Wednesday, June 3, 2015

GCS: Saying What We Mean

The Gist:  The Glasgow Coma Scale (GCS) is widely used, yet complicated by clunkiness and poor inter-rater reliability (explanation of kappa).  The Simplified Motor Score (SMS) is easier to use and equivalent, although this is prone to similar limitations.  Until a better means of communicating mental status comes, it may be best to communicate what the patient is doing (opening eyes to voice, moaning incomprehensibly, localizing pain). See this ScanCrit post.

The Case: A 29 year old male involved in a MVC with multiple traumatic injuries resulting in a prolonged ICU course at Janus General had a tracheostomy placed for respiratory failure.  The patient was responding appropriately to questions, following commands, opening his eyes spontaneous and lacked any signs of confusion or delirium, mouthing words, but was awaiting tracheostomy exchange for a fenestrated trach with a Passy-Muir valve.  What's the patient's GCS? Does this patient's GCS reflect their mental status?
  • Documented at as 10NT, 11T, and 15 by various providers.  The arguments behind each: 10NT - cannot test verbal, 11T -one point for showing up, 15 -patient oriented, and saying appropriate words, just without phonation.
In medicine, we communicate through abbreviations, codes, and numbers. When we see heart rate or blood pressure values we can place these numbers in the context of our knowledge of the patient’s peers. These numbers become actionable.  

Other critical components to the physical exam and evaluation are less easily quantified.  The mental status, for example, is a key component to evaluating a patient.  The GCS was developed to communicate the mental status of a head injured individual among providers during continuing care in a neurosurgical unit [1].  It is often used to track neurologic status when transferring care or over time.  A particular GCS in the prehospital setting may also qualify a patient for a trauma activation in some settings. 

Limitations: Unfortunately, unlike other vital signs, scores don't have explicit meaning.  The total GCS is often reported, yet this 13 point scale (3-15) actually has 120 different possible combinations.  A patient with a GCS of 10 may be completely oriented but totally paralyzed or be moaning incomprehensibly with their eyes own and a withdrawal reflex present.  Further, the sum of the GCS does not equal the parts, with regard to mortality. Healey et al used the National Trauma Database to model mortality predictions based on GCS and found that the same total sum score could be associated with double the mortality (ex: from 27% to 52%) depending on the individual components. Further, the mortality associated with scores is not linear [3].  So a GCS of 11, for instance may mean very different things for two different patients.

Yet, even if the numbers did mean something, the GCS has been found to have abysmal inter-rater reliability.  In one study, 19 emergency physicians rated 131 patients within five minutes of each other found a concordant GCS 32% of the time (Spearson's rho 75, weighted kappa 0.40) [4].   Even in the rather protected setting of case based written scenarios, emergency providers the overall GCS accuracy was 33.1% (95% CI, 30.2-36.0) [5].  In a written mock scenario, EMS personnel (n=178) generated an accurate GCS one-quarter of time without a scoring aid and a shocking 57% with the use of a scoring aid [7].

Alternatives: Given the inaccuracy of the GCS, Thompson et al set out to determine whether the performance of the SMS, a truncated version of the GCS was equivalent to the GCS in a retrospective cohort of out of hospital head injured patients. In the SMS, points are awarded for obeying commands (2), localizing pain (1), and withdrawing to pain or worse (0). They found that the predictive nature of the SMS paralleled that of the GCS, although the GCS seemed to predict mortality slightly better,  0.90 using GCS (0.88-0.01) vs 0.87 using SMS (0.86-0.88) [7].

So, what do we do?
Trashing the GCS is simply not an option for most of us; yet, score cards don't seem to do us any favors.  For example, during a trauma activation, the expectation (at least at Janus General) is to communicate to the room the patient’s GCS.  This may seem to convey more neurologic information than the actual exam discriminates. Recognizing the limitations to the GCS is important in discerning both what we do with this information and how we communicate what we mean, whether it's in documentation, to other providers, or family members.

  • Describe the exam.  With the knowledge of the subjectivity and poor reliability of the GCS, one may give the breakdown of points rather than a simple total GCS and describe the neurologic examination.  Documenting descriptors in medical records this may aid other teams in tracking the patient's exam.  
  • We may also engage in interdisciplinary discussions about use of simplified scoring systems such as the SMS or about the ways we communicate and document neurologic exams. 
1. Green SM. Cheerio, laddie! Bidding farewell to the Glasgow Coma Scale. Ann Emerg Med. 2011;58(5):427–30. doi:10.1016/j.annemergmed.2011.06.009.
2. Singh B, Murad MH, Prokop LJ, et al. Meta-analysis of Glasgow Coma Scale and Simplified Motor Score in predicting traumatic brain injury outcomes. 2013;27(March):293–300. 
3. Healey C, Osler TM, Rogers FB, et al. Improving the Glasgow Coma Scale score: motor score alone is a better predictor. J Trauma. 2003;54(4):671–678; discussion 678–680. 
4. Beveridge R, Ducharme J, Janes L, Beaulieu S, Walter S. Interrater reliability of Glasgow Coma Scale scores in the emergency department. Ann Emerg Med. 2004;43(February):215–223. 
5. Bledsoe BE, Casey MJ, Feldman J, et al. Glasgow Coma Scale Scoring is Often Inaccurate. Prehosp Disaster Med. 2014. doi:10.1017/S1049023X14001289.
6. Feldman A, Hart KW, Lindsell CJ et al. Randomized controlled trial of a scoring aid to improve glascow coma scale scoring by emergency medical services providers. Ann Emerg Med. 2015 Mar;65(3):325-329.e2.
7. Thompson DO, Hurtado TR, Liao MM, Byyny RL, Gravitz C, Haukoos JS. Validation of the Simplified Motor Score in the out-of-hospital setting for the prediction of outcomes after traumatic brain injury. Ann Emerg Med. 2011;58(5):417–25. 

Friday, May 15, 2015

FOAM on the Spot - A Needle in a Haystack?

At the SAEM conference, I had the privilege of partaking in a didactic with Dr. Anand Swaminathan, Dr. Ryan Radecki, and Dr. Matt Astin entitled, "FOAM on the Spot - Integration of Online Resources into Real-Time Education and Patient Care."

The cornucopia of free open access medical education (FOAM) resources may be overwhelming and I get frequent requests for guidance sorting through the cornucopia of FOAM.  People often have the question, "I remember hearing about this technique but I can't recall which site and want to review it..."  As such, I've posted a recording of my portion of the didactic here.

The Gist:
  • Filter FOAM by searching relevant information - FOAMsearch [1].
    • Customized Google search engine of 300+ blogs related to EM/critical care plus journal articles.
  • Engage in the community of personal librarians - Twitter (a few pearls on Twitter)
    • Tag others when you have a question
    • Participate in discussions and "be the librarian" for others.
  • Use a system to stay organized and collate resources - AgileMD.
    • Pro - Can collate several FOAM blogs, PV cards from Academic Life in Emergency Medicine, WikEM, and podcast notes all in one application on a smart phone/tablet.
    • Con - Presently can only build a "library" from a limited number of resources.
As a rather junior individual, selfishly, always welcome constructive feedback on my talks. This is my experiment in crowdsourcing feedback from the FOAM community to become a better presenter.

1. Raine T, Thoma B, Chan TM, Lin M. A custom search engine for emergency medicine and critical care. Emerg Med Australas. 2015;(March):n/a–n/a. doi:10.1111/1742-6723.12404.

Monday, December 29, 2014

Medicine's Third: Polypharmacy

The Gist: Polypharmacy, the concurrent use of multiple medications (5+) or use of unnecessary medications, is problematic in medicine.  Consider “medication related problem” on the differential diagnosis and review the patient’s medications.  When prescribing a medication, consider the unwanted reactions and tailor therapy, recalling that medications frequently have subtle or additive effects that may be especially problematic in the elderly. When in doubt, send a communication to a patient's PCP.

The Case: A 58 y/o with a history of hypertension and diabetes presented with weakness, vomiting, and fatigue.  A basic chemistry panel returned with a creatinine of 3.8 mg/dL (last value, 0.9 mg/dL).  While initially it seemed as though the gentleman had prerenal acute kidney injury from vomiting, the patient revealed he had been taking both ibuprofen and naproxen for worsening arthritis, in addition to his prescribed ace-inhibitor and thiazide diuretic.  See another case in this post on medication reconciliation.

Newton's Third Law states:
"For every action there is an equal and opposite reaction.” 

We ponder this frequently looking at collisions or calculating billiard shots but I think this principle can be translated to medicine. In the medical realm we prescribe therapies for the primary action of that medication/intervention.  Yet, unintended consequences abound.  Despite the comically long “disclaimers” of side effects on advertisements, the additive effects, unintended as they may be, are often disguised in a patient’s presenting complaint.  Further, patients are often prescribed medication to mask the side effects of another medication. Struck by this during medical school, I created my own version:
Westafer’s Third Law of Medicine:
 “For every medication action there is an unequal and unintended reaction.” 

This came up recently in a discussion on Twitter regarding a new medication for hyperkalemia, targeted to combat the side effect of elevated potassium in patients on ACE-inhibitors, ZS-9. A medication for a medication side effect (with likely more broad application in reality).

Although prescriptions from the emergency department (ED) are likely a minority of offenders with regard to the volume of inappropriate medications, awareness of the role that medications may play in the patient’s complaint. Studies show that adverse drug events (ADEs) may be responsible for 10-12% of ED visits among patients > 65 years old, although the definition of adverse drug event and determination of causality vary based on the study [1-3].   A more recent Canadian database review demonstrated a lower prevalence of ADEs generating ED visits, 0.8%, but the methods leave something to be desired [4].

A small study by Chin and colleagues identified ED prescriptions for analgesia, notably NSAIDs, muscle relaxants, and narcotics, as an area for future intervention [5].  Interestingly, this paper was published prior to the massive spike in opioid prescriptions; thus, this area may be even more crucial presently [6].  

Polypharmacy, particularly in the elderly, is associated with an increase in the prevalence of falls, mortality, hospital admission, and hospital length of stay.  The elderly are more susceptible to many of these effects as clearance and metabolism change with age, and elderly patients tend to be on more medications. 

Drug-drug interaction - A medication alters the activity of another.  Example: warfarin + ciprofloxacin -> supratherapeutic INR and may lead to increased bleeding.
Drug-disease interaction - Medications that should be avoided in patients with specific medical conditions.  
  • Example: Use of aspirin 325 mg or non-steroid anti-inflammatories in patients with peptic ulcer disease.
Adverse effects - Many medications have more pronounced adverse effects in elderly patients, often because the pharmacokinetics, such as renal excretion, are altered and may predispose patients to acute kidney injury, delirium, or orthostatic hypotension.  Check out this podcast for more.
  • Example: Anticholinergic properties are abundant in medications, including antidepressants, antihistamines, and antipsychotics.  In the elderly these effects are more pronounced and are associated with hallucinations, impaired memory, tachycardia, falls, constipation, etc.
Unnecessary - Medications are frequently initiated and then continued without re-examination for appropriateness. A study of Veterans Association hospital discharges of patients age >65 y/o classified as "frail" found that 44% had at least one unnecessary medication at discharge [8]. These medications contribute to increase cost and may play a role in further drug interactions or adverse effects. 
  • Example: A H2 blocker such as ranitidine may be prescribed for prophylaxis but the anticholinergic effects can contribute to diminished cognition, constipation, etc (see above).
Under-recognized  A prospective observational study by Hohl and colleagues of ED patients > 65 y/o in Canada found ADEs in 8.3%-12.3%, depending on the breadth of the definition of ADEs.  A prospective study by Hohl et al found that many ADEs in the ED were not attributed as medication related, particularly in the older population [9]. 

ED Interventions
  • Consider the Third Law of Medication when pondering the differential diagnosis.  For example, geriatric fall patients should probably be screened for polypharmacy (What medications is the patient on?  Can the problem be explained by a medication?) and while prescribing medications (Is the medication truly necessary? Will it interact with any of their medications?  Does the patient need a bowel regimen or other precautions?)
  • Medication review in the ED.  The ED encounter can serve as an opportunity for an outsider to glance at the patients medications to gain a sense as to whether something may be dangerous or warrant further discussion with their primary physician.
  • Judicious prescription of medications.  In the ED, we often write for short courses of medication and may be lulled into the sense that these prescriptions don't matter, yet they may carry an unintended reaction.  Be familiar with medications that are common offenders.
    • The Beers' List has a long list of medications to avoid in the elderly, but often these aren't the biggest offenders (also note the STOPP criteria). The most common medications associated with ADEs, implicated in 67% of hospital admissions according to a national survey database, were: 
      • warfarin (33.3%)
      • insulins(13.9%)
      • oral antiplatelet agents (13.3%)
      • oral hypoglycemic agents (10.7) [1,4]
  • Targeted feedback to general practitioners regarding potentially problematic medications.  Many health systems and electronic medical records have easy ways to send messages to primary care physicians.  In the ED haste, these communications frequently take a back seat but may be important.  Yet, the ACEP Geriatric ED guidelines recommend referral to PCP for any concern for polypharmacy (>5 medications) or presence of any high risk medication [10].
  • ED pharmacists. Many study authors have called for increasing the role of ED pharmacists in identifying ADE related to medications [2].
1.Budnitz DS, Lovegrove MC, Shehab N, Richards CL. Emergency hospitalizations for adverse drug events in older Americans. N Engl J Med. 2011;365:(21)2002-12. 
2. Banerjee A, Mbamalu D, Ebrahimi S, Khan AA, Chan TF. The prevalence of polypharmacy in elderly attenders to an emergency department - a problem with a need for an effective solution. Int J Emerg Med. 2011;4(1):22.
3. Budnitz DS, Shehab N, Kegler SR, Richards CL. Medication use leading to emergency department visits for adverse drug events in older adults. Ann Intern Med. 2007;147:(11)755-65.
4.Bayoumi I, Dolovich L, Hutchison B, Holbrook A. Medication-related emergency department visits and hospitalizations among older adults. Can Fam Physician. 2014;60:(4)e217-22. 
5. Chin MH, Wang LC, Jin L, et al. Appropriateness of Medication Selection for Older Persons in an Urban Academic Emergency Department. Acad Emerg Med. 2007;6(12):1232–1242.
6. Ruscitto A, Smith BH, Guthrie B. Changes in opioid and other analgesic use 1995-2010: Repeated cross-sectional analysis of dispensed prescribing for a large geographical population in Scotland.Eur J Pain. 2015 Jan;19(1):59-66. 
7. Robitaille C, Lord V, Dankoff J, et al. Emergency Physician Recognition of Adverse Drug-related Events in Elder Patients Presenting to an Emergency Department. 2005;12(3). 
8.Hajjar ER, Hanlon JT, Sloane RJ, et al. Unnecessary drug use in frail older people at hospital discharge. J Am Geriatr Soc. 2005;53:(9)1518-23. 
9. Hohl CM, Zed PJ, Brubacher JR, Loewen PS, Purssell RA. Do Emergency Physicians Attribute Drug-Related Emergency Department Visits to Medication-Related Problems? YMEM. 2009;55(6):493–502.e4. 
10.American College of Emergency Physicians. Geriatric emergency department guidelines 2013

Saturday, November 22, 2014

Misrepresented: EBM

The Gist: Evidence based medicine (EBM) is misunderstood; it's not a randomized control trial (RCT) or "the literature." Rather, EBM is the intersection of the best available evidence, clinical expertise, and patient values [1-2]. Avoid BARF (Brainless Application of Research Findings), with tips from Emergency Medicine Cases

We have a cultural problem.  Clinicians are increasingly called upon to practice EBM.  Yet, the term EBM does not sit well on the palate of many physicians.  Conversations involving a mention of EBM have resulted in some of the following refrains...
"See, my patients are different..." 
"We'll never get an RCT on that..." 
"The culture is different here, I don't want to get sued." 
"Patients don't understand, but they do hold the power with satisfaction scores." 
"It's cookbook medicine."
With these words and reactionary body language, the dialogue quickly shuts down - by both parties.  First, this is a shame.  We should learn from one another but there seems to be a "hard stop" between many who champion EBM and those who find EBM off-putting. Second, this is a misunderstanding.  EBM is not an RCT.  In fact, EBM is not the best statistical methods or the rationing of care. EBM is not nihilism.  

EBM is the intersection of the best available evidence, clinical expertise, and patient values:
"the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research" [1].
Why, then, the misunderstanding? 
Here are some thoughts...

Misrepresentation. EBM is often used to refer to literature or studies, rather than to the application of research and evidence to particular patients and situations, using one's clinical experience (example and discussion: "EBM is Crap").  As a result, EBM may be misunderstood as a cost-cutting venture or a cookbook for medicine [3]. I have been complicit in perpetuating this misrepresentation of EBM.   As a novice physician-in-training with limited clinical experience, I draw predominantly upon the literature base.  I have unknowingly quoted the literature, thereby proudly proclaiming my practice of EBM, while unconsciously dismissing the other components of EBM.  
  • A remedy:  Remind ourselves and others that the evidence is part of the trifecta of EBM, along with the patient's values and clinical expertise.  We can be clear in what we mean by EBM and refrain from referring to a body of literature as EBM. 
Zeal. A religiosity exists amongst many champions of EBM, or people who believe they are championing EBM.  We tout our pyramids of evidence and may scoff at a lack of evidence or rigorous trials.  This may be off-putting as not all fields are amenable to RCTs and patient populations vary.  Moreover, there's a human tendency to form a reactionary attitude when someone exerts a strong identity [4].  Hence, EBM zeal may engender an anti-EBM attitude and cause people to be wary of solid practice changing evidence.
  • A remedy:  While championing good research and employing the best available evidence, we can balance our enthusiasm with important caveats and understand the importance for tailored approaches for patients.  Gentle education about EBM rather than diatribes may aid individuals in understanding the values of EBM beyond evidence.
Fear.  People like to be right.  We may reflexively become defensive when we are (possibly) wrong. EBM or "literature" can be used in an antagonizing way and, subconsciously, a way to exert a feeling of superiority.  "You haven't read that study?"
  • A remedy: Understand that unlearning in medicine is difficult.  Aggressive assertions may push people further away.  Think of it as a Kubler-Ross like grief cycle, as explained in this post.  This may help us become more cognitively flexible, understand the reticence of others, and perhaps make our points more effectively.  

Confusion.  Historically, researchers, clinicians, physicians in training, and allied health professionals have limited understanding of fundamental statistics [5,6].  As such, we may not understand what we're reading or how it applies to our patient population.  We may have difficulty understanding why something we believed was proper at one time is no longer the case.  Often, this is because the research was, in fact, initially wrong or misleading [7]. 
  • A remedy: Read.  This podcast proffers tips on getting started; however, even the most seemingly rigorous papers published in high impact journals are subject to bias (publication bias and otherwise), which can be difficult to parse through.  For example, the oseltamivir (tamiflu) recommendations from Cochrane changed after they were allotted access to data, demonstrating the profound impact of publication bias [Jefferson et al].  More on this here.
Time. The number of journal articles needed to read (NNR) to obtain valid and relevant information is typically cited as 20-200, an insurmountable task [8].  The process of trolling through the literature is time consuming and may be overwhelming.  Frustration can turn into apathy, confusion, and mistrust.
There are legitimate issues with EBM.  Evidence is often subject to the biases of industry and legislative bodies.  Guidelines or recommendations billed as "EBM" may be hijacked by individuals with conflicts of interest or other agendas. Further, the grading of evidence isn't always objective or consistent, as seen by the grading of evidence for thromboylitics in acute ischemic stroke listed in the ACEP clinical policy.   In addition, guidelines harness EBM and disseminate the body of evidence to practitioners.  For example, the 2008 AHA/ACC guidelines are based largely on low levels of evidence and expert opinion,  many of whom have financial conflicts of interest.  Only 11% of the recommendations were based on high quality evidence [9].  

So, while EBM has imperfections in concept, representation, and implementation, the model incorporates the primary things we, as providers, care about - the evidence, the patient, and clinical experience.  Let's understand what EBM means and apply the term and principles appropriately.

1. Sackett DL, Rosenberg WM, Gray JAM, et al. Evidence based medicine: what it is and what it isn’t. BMJ. 1996;312(7023):71–72. 
2. Greenhalgh T, Howick J, Maskrey N. Evidence based medicine: a movement in crisis? BMJ 2014;348:g3725
3. Straus SE, McAlister FA. Evidence-based medicine: a commentary on common criticisms. CMAJ. 2000;163(7):837–41. 
4.  Maalouf A.  In the Name of Identity: Violence and the Need to Belong. New York: Penguin Books, 2000.
5.  Windish D, Huot S, Green M. Medicine residents’ understanding of the biostatistics and results in the medical literature. Jama. 2007;298(9). 
6.  Mavros MN, Alexiou VG, Vardakas KZ, Falagas ME. Understanding of statistical terms routinely used in meta-analyses: an international survey among researchers. PLoS One. 2013;8(1):e47229. 
7.Ioannidis JP a. How many contemporary medical practices are worse than doing nothing or doing less? Mayo Clin Proc. 2013;88(8):779–81.
8. McKibbon KA, Wilczynski NL, Haynes RB. What do evidence-based secondary journals tell us about the publication of clinically important articles in primary care journals? BMC Med. 2004;2:33. 
9.  Tricoci P1, Allen JM, Kramer JM, et al.  Scientific evidence underlying the ACC/AHA clinical practice guidelinesJAMA. 2009 Feb 25;301(8):831-41.

Saturday, November 8, 2014

SBO Ultrasound

The GistAs mentioned in this post, the operating characteristics of historical and physical features are suboptimal in small bowel obstruction (SBO).  Bedside ultrasound has better operating characteristics and is one of the easier scans to perform and read.  Assuming others like to make their lives easier, I gave a talk on this; but professionals have created a tutorial at The Ultrasound Podcast tutorial.

I delivered a quick talk at the Controversies and Consensus in Emergency Medicine Conference on ultrasound for SBO, a modality that I've found great utility for in my developing practice. As a believer in Free Open Access Medical education (FOAM) and with hopes that, as a novice I might receive some constructive criticism to help me become better, I have posted the recording.

A Few Tidbits (some redundancy from prior post): 
Time.  Ultrasound for SBO is quick and easy and can be performed in conjunction with the history and physical exam in appropriate patients.  This may alleviate the time to definitive diagnosis (say CT or surgical evaluation), treatment, and/or disposition.*  Furthermore, sometimes we see things we don't expect on ultrasound.  Familiarity with US findings of SBO may make sense of dilated loops of bowel or altered peristalsis encountered during a gallbladder or aorta scan for abdominal pain.  Conversely, there are times when SBO may be suspected and a quick ultrasound may reveal an alternative diagnosis that may grossly change management (examples in talk).

X-rays are out for SBO.  Bedside ultrasound has better operating characteristics than plain films with fewer instances of equivocal results.  Sometimes plain films are crucial to evaluate for pneumoperitoneum but most patients with abdominal pain don't fall in this category.  Indeed, The American College of Radiology conclusion on plain films in suspected SBO
"In light of these inconsistent results, it is reasonable to expect that abdominal radiographs will not be definitive in many patients with a suspected SBO. It could prolong the evaluation period and add radiation exposure while often not obviating the need for additional examinations, particularly CT" [5].
  • Ileus vs. SBO - while US beats plain films with regard to percentage of ambiguous scans, ultrasounds can be equivocal as well.
  • Cause of obstruction/Transition point not well elucidated.  In patients with recurrent SBO from malignancy or adhesions and this may be less important to the managing team and surgeons often stop ordering CT scans if the presentation is consistent with prior presentations. 
  • Consultant access to images obtained at the bedside.
Note:  I have not included surgical consultants requiring a CT scan as part of the limitations.  The surgical literature recognizes the capacity of US to diagnose SBO, although this is not yet widely adopted [6].  However, despite common assumptions, surgeons don't require a CT scan for every recurrent SBO.  As a result, sometimes a positive ultrasound, followed by plain film, may be enough in these patients who will undergo conservative management.  Have a chat with each consultant, they're not always as inflexible as we make them out to be. 

*NCT02190981 pending with LOS as secondary outcome

1.  Carpenter CR, Pines JM. The end of X-rays for suspected small bowel obstruction? Using evidence-based diagnostics to inform best practices in emergency medicine. Acad. Emerg. Med. 2013;20(6):618–20.
2.  Taylor MR, Lalani N. Adult small bowel obstruction. Acad. Emerg. Med. 2013;20(6):528–44.
3. Böhner H, Yang Q, Franke C, Verreet PR, Ohmann C. Simple data from history and physical examination help to exclude bowel obstruction and to avoid radiographic studies in patients with acute abdominal pain. Eur. J. Surg. 1998;164(10):777–84. 
4. Jang TB, Schindler D, Kaji AH.  Bedside ultrasonography for the detection of small bowel obstruction in the emergency department. Emerg Med J. 2011 Aug;28(8):676-8.
5. Katz DS, Baker ME, Rosen MP, Lalani T, et al, Expert Panel on Gastrointestinal Imaging. ACR Appropriateness Criteria® suspected small-bowel obstruction. Reston (VA): American College of Radiology (ACR); 2013. 10 p.
Maung AA, Johnson DC, Piper GL et al. Evaluation and Management of Small-Bowel Obstruction.  J Trauma. 73(5):S362-S369, November 2012

Saturday, October 11, 2014

Euboxia - Not Necessary (Or Necessarily Normal)

The Gist:  In medicine, we historically strive towards achieving values that fall within a reference range, or are normal, a phrase coined "euboxia" [1].  Targeting treatments to normalize values may not result in patient-oriented benefit and may cause harm.  We must also consider that normal values may not necessarily be normal for our patients.  Data fatigue, the exposure to copious data, may lead to ignoring values that are not flagged as abnormal, regardless of the appropriateness for a patient.
"'Euboxia' (from the Greek 'eu' meaning good, normal or happy, and 'box' from the tradition of writing physiological variables in boxes) is a colloquial word used in many North American and other hospitals to describe the state of apparent perfection aimed at by residents by the time they present their patients on morning rounds" - MC Meade [2].
Euboxia Is Not Always Necessary
Chris Nickson's Free Open Access Medical education (FOAM) post on Euboxia highlights some of the pitfalls with this obsession with normalcy. He also delivered a talk Euboxia and (ab)Normality at SMACC Gold which will hopefully be available on the SMACC podcast in the near future. A few examples include:
  • Hemoglobin transfusion trigger in anemia - Studies such as TRICC, CRIT, SOAP, and TRISS demonstrate that transfusion targets of more "normal" hemoglobin levels is not advantageous and may incur increased risks.  As such, transfusion triggers, in the absence of active myocardial ischemia, have moved to <7 g/dL while uptake of this trigger remains low in some communities [4]. 
  • Oxygen saturation in COPD - Unless patients are under duress, guidelines suggest patients with COPD have oxygen saturations targeted to 88-92% rather than the 98-100% more often associated with perfection [5]
  • Blood gas and saturations in ARDS - Guidelines for ventilation in patients with ARDS aim to protect the lungs using low tidal volumes and plateau pressures at the expense of allowing a pH of 7.20, permissive hypercapnia, and lower oxygen saturations of 88-95% (paO2 55-80 mmHg).  Correction of these lab abnormalities may come at the cost of additional lung damage by means of higher pressures or volumes and are thus discouraged [6].
Euboxia Is Not Necessarily Normal
Euboxia, however, may fool also practitioners into a false sense of security.  Failure to truly see a value that appears normal and isn't flagged, red, or outside of the box may be problematic. A few examples:

Normotension - Hypotension typically refers to systolic blood pressure <90 mmHg or a drop in systolic blood pressure >40 mmHg.  The latter part of this definition is often unable to be determined (due to lack of information) or forgotten.  The trauma literature seems to have solidified around the notion that the widely accepted definition of hypotension does not apply to many trauma patients, particularly those > 65 years old, and that 110 mmHg is probably a better cutoff [9-12].  While these recommendations have been out since 2011,  90 mmHg remains the common cut point for hypotension.
  • The CDC triage guidelines/"National Trauma Triage Protocol" have suggested <110 mmHg as the new hypotension guideline in patients > 65 years of age as multiple registry studies have demonstrated that an SBP <110 mmHg is associated with increased mortality and has an improved AUC compared with other blood pressure cut offs [9]. 
    • An abstract presented at AAST in 2014 found that patients >65 y/o with an SBP 90-109 mmHg had an odds of mortality of 9.7 (95% CI 8.7-10.8, p<0.01).  This survey study found improved, but terrible sensitivity for Trauma Center Need (ISS>15, ICU admit, urgent OR, or ED death) with the higher SBP cut-off [10].
Normal White Blood Cell Count (WBC) - Leukocytosis is often used as a predictor of infection/inflammation and historically loved by surgical services, yet the operating characteristics don't perform that well.  During a lecture as a medical student Dr. Sean Fox (PEM Morsels) shared the following perspective on the WBC, "WBC is the last bastion of the intellectually destitute."
I soon discovered that the sensitivity and specificity of leukocytosis, or the absence thereof, wasn't helpful in many situations.
  • In acute cholecystitis, for example, the WBC proves unhelpful as demonstrated by the following operating characteristics for leukocytosis: +LR 1.5; -LR 0.6; Sensitivity 63%; Specificity 57% [13].  Thus, a normal WBC does not help rule out acute cholecystitis.  Similarly, a normal WBC does not exclude acute appendicitis, although values <8 (a normal value) may have some utility in this regard according to Bundy et al.  
Normal Potassium in DKA - The reference range for potassium runs approximately 3.5-5 mEq/L.  Patients presenting in DKA may have low normal potassium concentrations but have severe total body potassium deficits.  As a result, professional societies recommend withholding insulin if a patient has a potassium <3.5 and supplementing potassium even when values are well within the upper "normal" limit of 4-5 mEq/L [14].  Despite these teachings and nearly habitual practice, without mindful attention to the potassium the "normal" lab value could easily be ignored. 

Normal Lactate - Lactate is beloved in Emergency Department (ED) care and it's well accepted that elevated lactate values predict mortality.  Yet, normal lactate levels may be falsely reassuring.  Lactate has been used as screening test in mesenteric ischemia as small, early reports yielded a sensitivity of 100% [15].  More recent analysis, however, show that the +LR 1.7 (1.4–2.1), -LR 0.2 (0–2.9) for L-lactate.  The -LR for lactate crosses 1.0, demonstrating that a normal lactate is not useful in crossing mesenteric ischemia off the list [16].  While we may cognitively understand this notion, in practice I think we quite often feel reassured by normal lactates (or reassure the admitting teams).

What to do?
Data overload and obsession may engender a sort of "data fatigue."  It is difficult to notice abnormalcy in data that may appear, for most individuals, normal.  This may be particularly arduous in a sea of numbers.  Furthermore, our attention is typically drawn to the red or flagged "abnormal" numbers.  This is not to suggest that we should agonize over every value and cannot trust anything "normal."  Rather, it seems that the signal in medicine is that tests and parameters are only as good as the context of the patient and the provider interpreting them. Here's what I'm trying, to combat my own data fatigue and subconscious euboxic thinking:
  • Think about a patient's clinical context, which requires mindfulness in the fast pace and overwhelming environment we call an ED.
  • Order a test?  Review the results (really), paying attention and process the results in the context of the patient.
  • If possible and appropriate, prevent data overload and data fatigue by ordering tests that will add value to the care of the patient.
1.  Reade MC. The pursuit of oxygen euboxia. Anaesth Intensive Care. 2013;41(4):453–5.
2.  Reade MC. Should we question if something works just because we don’t know how it works? Crit Care Resusc. 2009;11(4):235–6. 
3. Nickson CN.  Don't Put Your Patient In A Box.  Life in the Fast Lane. 
4. Carson JL, Grossman BJ, Kleinman S et al.  Red blood cell transfusion: a clinical practice guideline from the AABB.*Ann Intern Med. 2012 Jul 3;157(1):49-58.
5. Abdo WF, Heunks LM. Oxygen-induced hypercapnia in COPD: myths and facts. Crit Care. 2012 Oct 29;16(5):323. 
6.The Acute Respiratory Distress Syndrome Network (2000) Ventilation with low volumes as compared with traditional tidal volumes for acute lung injury and acute respiratory distress syndrome. N Engl J Med 342:1301-1308 
7. Putensen C, Theuerkauf N, Zinserling J et al. Meta-analysis: ventilation strategies and outcomes of the acute respiratory distress syndrome and acute lung injury. Ann Intern Med. 2009 Oct 20;151(8):566-76.
10. Brown JB, Gestring ML, Forsythe RM et al. Systolic Blood PRessure Criteria in the National Trauma Triage Protocol for Geriatric Trauma: 110 is the new 90.  Oral Abstracts, AAST July 2014.
11. Eastridge BJ, Salinas J, McManus JG, et al. Hypotension begins at 110 mm Hg: redefining “hypotension” with data. J Trauma. 2007;63(2):291–7; discussion 297–9.
12. Oyetunji TA, Chang DC, Crompton JG, et al. Redefining hypotension in the elderly: normotension is not reassuringArch Surg. 2011;146(7):865–9.
13. Trowbridge RL, Rutkowski NK, Shojania KG. Does This Patient Have Acute Cholecystitis? JAMA. 2003;289(1):80–86.
14. Kitabchi AE, Umpierrez GE, Miles JM, Fisher JN. Hyperglycemic crises in adult patients with diabetes. Diabetes Care. 2009;32(7):1335–43. 
15. Lange H, Jäckel R. Usefulness of plasma lactate concentration in the diagnosis of acute abdominal disease. Eur J Surg. 1994;160(6-7):381.
16.  Cohn B.  Does This Patient Have Acute Mesenteric Ischemia?  Ann Emerg Med. 2014 Jan 30

Saturday, August 16, 2014

Open to Interpretation: Do Not ______

The Gist:  DNR (Do Not Resuscitate) orders are subject to variable interpretation by providers and patients whereas Physician Orders for Life Sustaining Treatments (POLST) are becoming increasingly common and have more specific, meaningful directives. As critical care providers, we should understand the meanings behind each of these documents, as well as the limitations.  The Annals of Emergency Medicine August 2014 podcast has a fantastic Free Open Access Medical education (FOAM) discussion of DNRs and POLSTs as they pertain to the physician in the Emergency Department (ED).  Despite these helpful aids, nothing replaces discussions with patients and their family members or health care proxies about treatment that is clinically appropriate and congruent with the patient's goals.

The Case:  A 82 y/o male presents to Janus General in respiratory distress, 72% on 4L of oxygen via nasal cannula up to 92% on 15L non-rebreather from the rehab facility where he is recuperating from a fractured tibia.  Previously in excellent health, he has been febrile and confused for the past two days with radiographic and clinical diagnosis of pneumonia and therapy with azithromycin and ceftriaxone at the facility.  Patient has a signed DNR order and an advance directive stating that for an irreversible/terminal condition the patient would not want artificial support.  The health care proxy is unavailable by phone and the patient lacks a clear sensorium but is in respiratory distress, appears septic, and has a chest x-ray with clear infiltrate and interstitial pattern that may indicate early ALI/ARDS.
  • What should happen?  BiPAP?  Morphine? Intubation?  What's this patient's disposition?  At Janus General, the providers in the ED and the inpatient team disagreed about what the patient's course should be, whether or not the condition was "reversible," and what the patient would want in this situation.  
In a recent post I shared a talk on tips for palliative care in the ED setting.  Despite our best efforts in the ED, uncovering documents such as DNRs and advance care directives may obscure the picture more than provide clarity.  I discovered on rotations through critical care units that the presence of a DNR seemed to bias both myself and my colleagues regarding the care of patients that was unrelated to the performance of cardiopulmonary resuscitation.  I believe we acted based on what we felt was clinically appropriate in the patient's situation but upon closer inspection, I think we were occasionally subject to a touch of another form of bias - The DNR bias.

The Do Not Resuscitate (DNR):  A medical order that specifies one not initiate cardiopulmonary resuscitation (CPR) in a patient who has died (pulseless/apneic) [1].
  • Technically, applies to a dead patient.
  • Does not indicate a patient's general wishes for medical care, only their preference regarding initiation of CPR. 
The Problem With The DNR
DNR orders, which technically only speak to a patient's wishes to receive CPR, have variable interpretations amongst healthcare professionals and, likely, patients [2-4].  The issue lies in the word "resuscitate," which may be used to include fluids, antibiotics, vasopressors, advanced means of ventilation or, at the extreme, CPR.
  • The TRIAD II-IV studies surveyed EMS personnel, physicians, and medical students respectively and provided the participants with an advance care directive as well as case scenarios.  The participants then indicated whether a patient was a DNR or full code and the appropriate action.  Both physicians and EMS providers performed poorly and variably, indicating that the directives were not clear [2,4].
DNR orders may mean that patients receive care that differs from their wishes or standard medical practice.  This demonstrates that the DNR bias may exist, even if it's partially a reflection of a patient's general clinical situation.
  • Aspirin is a non-intensive and relatively safe standard intervention in patients with acute myocardial infarction (AMI) (NNT=42, NNH=167). In patients with an AMI, the Worcester Heart Attack study demonstrated a negative association between aspirin administration and those patients with a DNR [5].  Of note, the individuals in this study with a DNR were "sicker," meaning they had comorbidities or other poor prognostic signs such as shock.  Other markers of more aggressive care such as PCI, thrombolytics, and cardiac catheterization, were also reduced in the DNR cohort.  Therefore, it is possible that this association may represent the belief that these patients were not candidates for these interventions independent of their DNR status.
  • The Worcester Heart Failure study also demonstrated that patients with a DNR were less likely to receive any quality assurance intervention than those with no DNR (HR 0.52, adjusted HR 0.63- 0.4-0.99) [7].  This may have been appropriate given the clinical situation of the patients.
But, it's not all about the co-morbidities:
  • Residents in Missouri nursing homes with a DNR were less likely to be hospitalized following a LRTI (OR 0.69; 0.49-0.97).  Compared with the Worcester Heart Attack study, patients with comorbidities were more likely to receive aggressive treatment (hospitalization) than those without a DNR (excluded patients with a Do Not Hospitalize order) [7].  
The Physician Order for Life Sustaining Treatment (POLST)Physician orders, on a standardized form, that are designed to transfer amongst settings, following an individual from home to hospital and nursing home/rehabilitation facilities.  Most states have POLST programs or are in the process of developing them these programs (map of programs) and some have online registries for providers, mitigating issues with located print copies.  Jesus et al give a good rundown of POLSTs in the ED in Annals of Emergency Medicine, August 2014 [8].

These may be more meaningful in the critical setting of the ED as they may indicate a patient's preference for a broad array of clinical conditions encountered.  For example, in Massachusetts, the back portion of the MOLST resembles a sushi menu where individuals can opt to specify whether they would accept non-invasive ventilation, dialysis, artificial hydration or nutrition and, if yes, whether temporarily or permanently.

Issues with POLSTs:
  • Require a physician signature and require either medical literacy or a good deal of physician explanation.  
  • It is possible that only the sickest patients or those with terminal illnesses may be prompted to have a POLST.
  • Components are still open to interpretation by providers as the reversibility or predicted length of therapy are often difficult to determine upon initiation.  
  • The FOAM blog, GeriPal, has an interesting discussion on the semantics prevalent in the POLST.  For example, the connotation of the word "only" following Comfort Measures is not necessary and undermines the intensive work often required for end of life comfort.  The blog offers some suggestions that may surface as POLSTs become increasingly adopted.
1. Dugdale DC. .Do Not Resuscitate Orders."  MedlinePlus Medical Encyclopedia.  
2.  Mirarchi FL, Kalantzis S, Hunter D, McCracken E, Kisiel T. TRIAD II: do living wills have an impact on pre-hospital lifesaving care? J Emerg Med. 2009;36(2):105–15. doi:10.1016/j.jemermed.2008.10.003.
3. Mirarchi FL, Costello E, Puller J, Cooney T, Kottkamp N. TRIAD III: nationwide assessment of living wills and do not resuscitate orders. J Emerg Med. 2012;42(5):511–20. doi:10.1016/j.jemermed.2011.07.015.
4.Mirarchi FL, Ray M, Cooney T.  TRIAD IV: Nationwide Survey of Medical Students' Understanding of Living Wills and DNR OrdersJ Patient Saf. 2014 Feb 27. 
5. Gurwitz JH, Lessard DM, Bedell SE, Gore JM. Do-Not-Resuscitate Orders in Patients Hospitalized With Acute Myocardial Infarction. 2014;164.
6. Chen JLT, Sosnov J, Lessard D, Goldberg RJ. Impact of do-not-resuscitation orders on quality of care performance measures in patients hospitalized with acute heart failure. Am Heart J. 2008;156(1):78–84. doi: 10.1016/j.ahj.2008.01.030.4. 10.1002/jhm.2234
7. Zweig SC, Kruse RL, Binder EF, Szafara KL, Mehr DR. Effect of do-not-resuscitate orders on hospitalization of nursing home residents evaluated for lower respiratory infections. J Am Geriatr Soc. 2004;52(1):51–8. 
8. Jesus JE, Geiderman JM, Venkat A, et al. Physician Orders for Life-Sustaining Treatment and Emergency Medicine: Ethical Considerations, Legal Issues, and Emerging Trends. Ann Emerg Med. 2014;64(2):140–144. doi:10.1016/j.annemergmed.2014.03.014.

Wednesday, July 30, 2014

Seduction, Hype, and the Tradition - FOAM as Effective Learning

I had the phenomenal opportunity to present at SMACC in Australia and it's now out there on the SMACC podcast or here
 So, here are some of the references/resources I promised.  This fantastic conference will be held in Chicago, June 2015 - book your leave!

The Gist - Whether Free Open Access Medical Education (FOAM) represents gizmo idolatry or effective learning depends - not on the resource, but on the user.  Consider treating FOAM like a parachute, for which there are also no human randomized controlled trials - perform safety checks, examining FOAM closely for holes and actively identify and repair these before they become unsafe, start with “tandem jumps," guided through FOAM, directed by teachers, a curator, or role model and teach others the necessary critical thinking and skills needed for successful solo jumps.  Like any educational resource, FOAM can be gizmo idolatry or powerfully effective learning, so let's use FOAM effectively.

Gizmo Idolatry 
Gizmo idolatry, coined by Leff and Finucane, is our intrinsic preference for a technologically advanced approach than one that is less technological.  We're seduced by new technologies/innovations because we like to be on the cutting edge and because they "make sense," are sexy and full of hype.  Often this occurs before the evidence is in, which may show that these interventions don't pan out.  Recent clinical examples revolve around robotic surgery and coronary CT.  Some argue that, as a "new" and popular educational intervention without significant evidentiary basis, FOAM can be gizmo idolatry for the following reasons:
  • Superficial learning/absorption of information (See post: "But I heard it on a podcast..")
  • Over reliance on multi-tasking, which is not as effective as we like to believe [1]
  • Lack of focus on core content and over-emphasis on the fun parts of medicine like airway and memes  (Note: This was one motivation behind co-founding FOAMcast)
  • Sometimes FOAM can even be wrong, as evidenced by one of my own experiences in which I placed part of an algorithm from a peer reviewed journal in this blog post, only to be corrected within hours in post-publication peer review (the individual caught the error in the peer-reviewed journal as well).
Note: it's important to realize that superficial learning, inaccurate information, idolatry, and enjoyment of the fun parts of medicine are not unique to FOAM, rather part of human nature and can be present in classrooms, conferences, peer-reviewed literature, etc.

Effective Learning

While the evidence for the efficacy of FOAM is currently lacking, there is an evidentiary underpinning behind some ways in which we can use FOAM.  Used smartly, FOAM can naturally harness some of the most evidence based learning modalities, spaced repetition and practice testing, and encourage learners to engage in learning and critical thinking[2].  

Spaced Repetition - We learn better in small aliquots over time because we tend to forget things over time, but when we're reminded repeatedly, or "beaten over the head" with a fact, we retain the information better [2].  This learning theory, which has been born out in medical education RCTs, happens naturally in FOAM, as contributors cover the same topic repeatedly, particularly when information is pushed to the learner (RSS feeds, Twitter).  See this post:  "Drinking From the Firehose - One Sip of FOAM at a Time"
Practice Testing - One of the most highly effective learning interventions as it provides learners with immediate feedback in an often non-threatening way [4-5].  FOAM examples include the repository at Life in the Fast Lane and the Detroit Receiving EM blog.

The Pause Principle - Pausing during lectures can allow learners to think and assess what they're learning as it can allow time for clarification and collaboration during an otherwise passive absorption of content [6,7].  This is one appeal of podcasts.

Highlighting the Things We Don't Know that We Don't Know- We often overestimate our abilities or knowledge, especially as novices.  When pushed to us in RSS feeds, podcasts, or tweets, FOAM can expose us things that we would otherwise never seek out, particularly things we think we're good at or know well. This is detailed in this blog post "We Don't Know What We Don't Know, which highlights the


1.Kirschner P a., van Merriënboer JJG. Do Learners Really Know Best? Urban Legends in Education. Educ Psychol. 2013;48(3):169–183.  
2.  Dunlosky J, Rawson K, Marsh EJ, Nathan MJ, Willingham DT. Improving Students’ Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology. Psychol Sci Public Interes. 2013;14(1):4–58. 
3  Larsen DP, Butler AC, Roediger HL. Comparative effects of test-enhanced learning and self-explanation on long-term retention. Med Educ. 2013;47(7):674–82. 
4.  Chan JC, McDermott KB, Roediger HL. Retrieval-induced facilitation: initially nontested material can benefit from prior testing of related material.  J Exp Psychol Gen. 2006 Nov;135(4):553-71.
5.Larsen DP1, Butler AC, Roediger HL.  Repeated testing improves long-term retention relative to repeated study: a randomised controlled trial. Med Educ. 2009 Dec;43(12):1174-81.
6. Ruhl KL, Hughes C a., Schloss PJ. Using the Pause Procedure to Enhance Lecture Recall. Teach Educ Spec Educ J Teach Educ Div Counc Except Child. 1987;10(1):14–18. 
7.  Di Vesta FJ, Smith D a. The pausing principle: Increasing the efficiency of memory for ongoing events. Contemp Educ Psychol. 1979;4(3):288–296. 

Thursday, July 17, 2014

CRITICAL Care - End of Life in the ED

The Gist: Palliative care is an emerging field in Emergency Medicine and most of us are inadequately equipped to discuss end of life issues, death and dying, which are all quite common in the Emergency Department (ED) [1].  We often feel uncomfortable in these situations as our instinct remains - resuscitate first, ask questions later. In a community that values cutting edge, critical care medicine, I was stunned when I realized that Free Open Access Medical education (FOAM) has engendered me to think twice about a procedure and take the time to ascertain what a patient actually wants.

These FOAM resources changed my course as a budding Emergency Physician and made me realize how ill equipped I was to handle dying patients, despite the frequency with which I encounter them.  As such, I felt compelled to use my slot at our residency conference dedicated to critical care to discuss end of life issues with my colleagues.  Here it is as FOAM, since I hassle others to share their talks.

EMCrit with Dr. Ashley Shreves "Critical Care Palliation"
The Geripal Blog - The Importance of Language

The Take Home
Run these ABCD's in tandem with our typical ABCs (Airway, Breathing, Circulation) because the trajectory that we launch patients on matters - whether it's to the ICU with an endotracheal tube, to dialysis with a line, or a palliative care consult [1, 6-9,15].

Advance Care Directives (does the patient have one?), Ask the patient/caregivers what they want.
  • Identify if a patient has a health care proxy or physician order for life sustaining treatment (POLST).  
  • Use appropriate language, avoid jargon.  The phrase, "Do Not Resuscitate (DNR)," is falling out of favor and major societies are now using the language "Allow Natural Death"[3]. Try replacing DNR with "It sounds like she would want a natural death."  
  • Dying patients, even those with DNR orders, Comfort Measure Only orders, or those with Do Not Hospitalize directives come to the hospital because dying is hard, uncomfortable, and stressful.  Figure out what they want and need, it's not always a tube or a line.
Better - Make the patient feel better
  • Turn off monitors or beeping pumps (especially if they're beeping), generously dole out opioids for dyspnea/pain, offer various means of respiratory relief (non-rebreather, nasal cannula, non-invasive ventilation).
Caregivers - identify the patient's caregivers and Communicate with all parties in appropriate language
  • As above, use appropriate language, avoid jargon.  My favorite phrase, effective on nearly all patients, "What is most important right now?"
Decisions - offer medically appropriate decisions in ways patients and caregivers can understand.  Aggressive resuscitation and cardiopulmonary resuscitation (CPR) are appropriate in many situations, but not all.  Think about the downstream consequences, positive and negative, of various courses of action.
  • The publics perception of CPR is largely misinformed and studies show that most people overestimate the success of CPR to hospital discharge.  One study of patients over 70 years of age found over half believed survival after CPR was >50% and 23% believed survival to discharge was >90% after CPR [2].  Furthermore, people may not understand that CPR does reverse the underlying process and a patient is typically sicker after CPR than they were before.  Let patients know the implications of these decisions.  For example, once someone dies, CPR involves chest compressions which often result in broken ribs but sometimes restart the heart.  There's no guarantee that if we restart the heart that we will get his/her brain function back.
  • If appropriate, offer more than one option and recognize the power and responsibility that comes with the entrusted title of physician.  People do listen to provider recommendations [5].  For example, some patients may want aggressive testing and treatment for etiologies of dyspnea, some may want oral antibiotics for a pneumonia if it may improve their shortness of breath, and some may opt solely for opioids. 
1. Members of the Emergency Medicine Practice Committee.  Emergency Department Palliative Care Information Paper June 2012.   ACEP 
2. Adams DH, Snedden DP. How misconceptions among elderly patients regarding survival outcomes of inpatient cardiopulmonary resuscitation affect do-not-resuscitate orders. J Am Osteopath Assoc. 2006;106(7):402–4. 
3. Breault JL. DNR, DNAR, or AND? Is Language Important? Ochsner J. 2011;11(4):302–6. 
4. Cassel JB, Kerr K, Pantilat S, Smith TJ. Palliative care consultation and hospital length of stay. J Palliat Med. 2010;13(6):761–7. doi:10.1089/jpm.2009.0379.
5. Cook D, Rocker G. Dying with Dignity in the Intensive Care Unit. N Engl J Med. 2014;370(26):2506–2514. doi:10.1056/NEJMra1208795.
6. DeVader TE, Albrecht R, Reiter M. Initiating palliative care in the emergency department. J Emerg Med. 2012;43(5):803–10. doi:10.1016/j.jemermed.2010.11.035.
7. DeVader TE, Jeanmonod R. The effect of education in hospice and palliative care on emergency medicine residents’ knowledge and referral patterns. J Palliat Med. 2012;15(5):510–5. doi:10.1089/jpm.2011.0381.
8. Lamba S, Mosenthal AC. Hospice and palliative medicine: a novel subspecialty of emergency medicine. J Emerg Med. 2012;43(5):849–53. doi:10.1016/j.jemermed.2010.04.010.
9. Lamba S, Quest TE. Hospice care and the emergency department: rules, regulations, and referrals. Ann Emerg Med. 2011;57(3):282–90. doi:10.1016/j.annemergmed.2010.06.569.
10. Schmidt TA, Zive D, Fromme EK, Cook JNB, Tolle SW. Physician orders for life-sustaining treatment (POLST): lessons learned from analysis of the Oregon POLST Registry. Resuscitation. 2014;85(4):480–5. doi:10.1016/j.resuscitation.2013.11.027.
11. Wright A a, Keating NL, Balboni T a, Matulonis U a, Block SD, Prigerson HG. Place of death: correlations with quality of life of patients with cancer and predictors of bereaved caregivers’ mental health. J Clin Oncol. 2010;28(29):4457–64. doi:10.1200/JCO.2009.26.3863.
12. Wu FM, Newman JM, Lasher A, Brody A a. Effects of initiating palliative care consultation in the emergency department on inpatient length of stay. J Palliat Med. 2013;16(11):1362–7. doi:10.1089/jpm.2012.0352.

Monday, June 23, 2014

Dip the Tap? - Diagnosis of Spontaneous Bacterial Peritonitis at the Bedside

The Gist:  Study results of urine reagent strips for the bedside diagnosis of spontaneous bacterial peritonitis (SBP) are highly variable with sensitivities from 45-100%.  Some suggest that certain dipsticks, if at least Grade 3 positive, have a great positive predictive value and positive likelihood ratio; thus, initiating treatment for SBP is likely a good idea.  A negative result, however, cannot rule out SBP, and this test is subject to limitations such as which reagent strip one has, what qualifies as "positive," and the prevalence of SBP at that location.  Suspect SBP or sick patient? Give antibiotics.

Why the enthusiasm in the Emergency Department (ED)?
A bedside test for diagnosis of SBP is neat and could potentially help identify an infective source earlier than standard laboratory tests (ascitic fluid cell count of >1000 WBCs or >250 polymorphonuclear neutrophils (PMNs) [1].  This laboratory endeavor takes time and reagent test strips commonly referred to as "urine dipsticks" have surfaced as a candidate.  Some studies cite a time "savings" of 2-3 hours using these strips as one may start targeted antibiotics after the bedside test [6].  In an era of source control and "time to antibiotics" measures in sepsis, early diagnosis of SBP has potential benefit.
Photo: Nottingham Vet School
Typical reagent strips, like the one above, demonstrate different grades of positivity, indicated by the color of the individual block.  Here, the leukocytes are indicated by the box on the far left of the image in which presence of leukocytes is quantified by reaction via leukocyte esterase.  These are read at the bedside after a certain period of time elapses (often 1-2 minutes), either by a person or machine. The pictured stick has a negative (off white), Grade 1 (slightly less off white), Grade 2 (lavender), Grade 3 (darker lavender/purple).

One important lesson that Free Open Access Medical education (FOAM) has hammered home, however, is the importance of understanding how to use a test prior to adoption.  On a recent episode of FOAMcast, we discovered that the core text, Rosen's Emergency Medicine references the positive correlation between SBP and a "positive" dipstick [1].  Unfortunately, the text doesn't go into how specifically to use the test or limitations, which could potentially lead to misapplication.  As an excited resident, I might opt to test this trick of the trade out without investigating exactly how it could or should change my practice. Furthermore, major societies currently recommend against the use of these test strips [2,3].

The Early Literature Hype
The initial studies were promising and cited sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Values (NPV) of 100% [4].  These studies also had relatively small numbers (n=31-257) and were conducted in a variety of settings with limited ED patients [4].  A positive test, in the majority of studies, was any result other than negative.  Some authors, including Gaya et al, called for the ability to rule out SBP based on a negative dipstick (Multistix 10SG) [5].

The Shifting Tide:  The many studies that subsequently followed had varied results and few were conducted in the Emergency Department (ED).  These studies used a variety of strips (Multistix - most commonly tested, Nephur, Combur, Uriscan, Aution Combina, and Choiceline) and demonstrated widely variable predictive scores with sensitivities of approximately 65% in nearly half of the studies and one study with a sensitivity of merely ~45%.  The specificity in these studies, however, remained quite high at >90% [4].  This literature is summarized nicely in a meta-analysis by Nguyen-Khac et al.
  • Multistix (n=12 studies): Sensitivities ranged from 45.3-100%, with higher sensitivities when a lower grade was used as "positive" (64.7-100%) [4].
A more recent study that was not included in this analysis posed a head-to-head ED based comparison between Uri-Quick Clini 10SG and MultistixSG10 in a population with a relative high incidence of SBP - 21.9% (49/223 samples).  Both strips had comparable specificities in the ~98% range.  This study more accurately depicts the way in which one might use reagent test strips, the importance of understanding which strip one has access to and its test characteristics, and the authors emphasize that the test does not rule out or replace the cell count [7].
  • Uri-Quick Clini 10SG Sensitivity 79.6% (64-87); + LR 33.7 (13-90); - LR 0.22 (0.13-0.38)
  • MultistixSG10: Sensitivity 77.5% (64-88%); + LR 33.6 (12.66-89.91); -LR 0.23 (0.14-0.39)
Why the variation?
  • Strips calibrated for urine so they don't match up to the PMN threshold for SBP.  As a result, what qualifies as a "positive" test varies - some studies used any level of positivity as "positive" and some specified a particular "Grade." 
  • Reading times of reagent strips varies and may impact results.
  • Different types of strips - the matrix and enzymes in strips varies based on manufacturer which may affect performance.  The strips used (ex: Aution sticks with high sensitivity) are not universally available [4,7].
  • Subjective interpretation of strips - This is a potential problem; however, the interrater reliability (kappa) was 0.8-0.94 (excellent!) in the studies in which it was calculated [6,7].  This is also dependent on whether the stick is read by a human or a machine (spectrophotometry).  
  • Varying prevalence of SBP in studied population (7-20%) [4,6].
What Now?
  • A 2012 study out of Mexico by Uribe et al demonstrates the utility of reagent strip testing as a rapid rule in diagnosis for SBP in low resource settings, with the caution that it is not a "rule out" test [7].  
  • SBP is associated with great mortality indicative of a very sick population, with an estimated survival after a patient's first episode of 68.1% at 1 month and 30.8% at 6 months [8].  As a result, it's probably best to suspect SBP in any sick cirrhotic, understand the limitations of the clinical exam, and administer antibiotics early in these patients.  Even if these patients get a non-targeted dose of piperacillin-tazobactam, this antibiotic still covers most SBP (although agents of choice are typically cefotaxime 2 grams IV Q4-8 hours or ceftriaxone 2 grams IV Q24 hours) [8].
  • Look for use of reagent strips at the bedside in the future for SBP but, like any test, understand the variability, the limitations, and the ways that the test is usable in one's own ED. 
1.  Oyama L.  Chapter 90:  Disorders of the Liver and Biliary Tract.  Rosen's Emergency Medicine, 8e (2014).  pp 1186-1204.
2.  European Association for the Study of the Liver.  EASL clinical practice guidelines on the management of ascites, spontaneous bacterial peritonitis, and hepatorenal syndrome in cirrhosis. J Hepatol. 2010 Sep;53(3):397-417.
3.  Runyon BA.  Management of Adult Patients with Ascites  Due to Cirrhosis: Update 2012.  (2013) doi: 10.1002/hep.00000
4.  Nguyen-Khac E1, Cadranel JF, Thevenot T, Nousbaum JB. Review article: the utility of reagent strips in the diagnosis of infected ascites in cirrhotic patients. Aliment Pharmacol Ther. 2008 Aug 1;28(3):282-8.
5. Gaya Dr, Lyon DB, Clarke J et al. Bedside leucocyte esterase reagent strips with spectrophotometric analysis to rapidly exclude spontaneous bacterial peritonitis: a pilot study. Eur J Gastroenterol Hepatol. 2007 Apr;19(4):289-95.
6.  Nousbaum JB, Cadranel JF, Nahon P, et al. Diagnostic accuracy of the Multistix? 8 SG reagent strip in diagnosis of spontaneous bacterial peritonitis. Hepatology 2007; 45: 1275–81.
7.  Uribe M, Vargas-vorackova F. Rapid diagnosis of spontaneous bacterial peritonitis using leukocyte esterase reagent strips in Emergency. 2012;11(5):696–699.
8.  O’Mara SR, Gebreyes K.  Chapter 83. Hpeatic Disorders, Jaundice, and Hepatic Failure. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e. New York, NY: McGraw-Hill; 2011. p 566-574