Showing posts with label Sepsis. Show all posts
Showing posts with label Sepsis. Show all posts

Wednesday, May 2, 2018

Hollow Hegemony: The Opportunity Costs of Overemphasizing Sepsis


Protocols are to make complex tasks simple, not simple tasks complex. - Scott K Aberegg

Yet here we find ourselves some 16 years after the inauguration of the Surviving Sepsis Campaign, and their influence continues to metastasize, even after the message has been hollowed out like a piece of fallen, old-growth timber.

Surviving sepsis was the brainchild of Eli Lilly, who, in the year after the ill-fated FDA approval of drotrecogin-alfa, worried that the drug would not sell well if clinicians did not have an increased awareness of sepsis. That aside, in those days, there were legitimate questions surrounding the adoption and implementation of several new therapies such as EGDT, corticosteroids for septic shock, Xigris for those with APACHE scores over 25, intensive insulin therapy, etc.

Those questions are mostly answered. Sepsis is now, quite simply, a complex of systemic manifestations of infection almost all of which will resolve with treatment of the infection and general supportive care. The concept of sepsis could vanish entirely, and nothing about the clinical care of the patient would change: an infection would be diagnosed, the cause/source identified and treated, and hemodynamics and laboratory dyscrasias supported meanwhile. There is nothing else to do (because lactic acidosis does not exist.)

But because of the hegemony of the sepsis juggernaut (the spawn of the almighty dollar), we are now threatened with a mandate to treat patients carrying the sepsis label (oftentimes assigned by a hospital coder after the fact) with antibiotics and a fluid bolus within one hour of triage in the ED. Based on what evidence?

Weak recommendation, "Best Practice Statement" and some strong recommendations based on low and moderate quality evidence.  So if we whittle it down to just moderate quality of evidence, what do we have?  Give antibiotics for infections, and give vasopressors if MAP less than 65.  But now we have to hurry up and do the whole kit and caboodle boiler plate style within 60 minutes?

Sepsis need not be treated any differently than a gastrointestinal hemorrhage, or for that matter, any other disease.  You make the diagnosis, determine and control the cause (source), give appropriate treatments, and support the physiology in the meantime, all while prioritizing the sickest patients.  But that counts for all diseases, not just sepsis, and there is only so much time in an hour.  When every little old lady with fever and a UTI suddenly rises atop the priorities of the physician, this creates an opportunity cost/loss for the poor bastard bleeding next door who doesn't have 2 large-bore IVs or a type and cross yet because grandma is being flogged with 2 liters of fluid, and in a hurry.  If only somebody had poured mega-bucks into increased recognition and swift treatment of GI bleeds....


Petition to retire the surviving sepsis campaign guidelines:

(Sign the Petition Here.)

Friends,

Concern regarding the Surviving Sepsis Campaign (SSC) guidelines dates back to their inception.  Guideline development was sponsored by Eli Lilly and Edwards Life Sciences as part of a commercial marketing campaign (1).  Throughout its history, the SSC has a track record of conflicts of interest, making strong recommendations based on weak evidence, and being poorly responsive to new evidence (2-6).

The original backbone of the guidelines was a single-center trial by Rivers defining a protocol for early goal-directed therapy (7).  Even after key elements of the Rivers protocol were disproven, the SSC continued to recommend them.  For example, SSC continued to recommend the use of central venous pressure and mixed venous oxygen saturation after the emergence of evidence that they were nonbeneficial (including the PROCESS and ARISE trials).  These interventions eventually fell out of favor, despite the slow response of SSC that delayed knowledge translation. 

SSC has been sponsored by Eli Lilly, manufacturer of Activated Protein C.  The guidelines continued recommending Activated Protein C until it was pulled from international markets in 2011.  For example, the 2008 Guidelines recommended this, despite ongoing controversy and the emergence of neutral trials at that time (8,9).  Notably, 11 of 24 guideline authors had financial conflicts of interest with Eli Lilly (10).

The Infectious Disease Society of America (IDSA) refused to endorse the SSC because of a suboptimal rating system and industry sponsorship (1).  The IDSA has enormous experience in treating infection and creating guidelines.  Septic patients deserve a set of guidelines that meet the IDSA standards.


Guidelines should summarize evidence and provide recommendations to clinicians.  Unfortunately, the SSC doesn’t seem to trust clinicians to exercise judgement.  The guidelines infantilize clinicians by prescribing a rigid set of bundles which mandate specific interventions within fixed time frames (example above)(10).  These recommendations are mostly arbitrary and unsupported by evidence (11,12).  Nonetheless, they have been adopted by the Centers for Medicare & Medicaid Services as a core measure (SEP-1).  This pressures physicians to administer treatments despite their best medical judgment (e.g. fluid bolus for a patient with clinically obvious volume overload).

We have attempted to discuss these issues with the SSC in a variety of forums, ranging from personal communications to formal publications (13-15).  We have tried to illuminate deficiencies in the SSC bundles and the consequent SEP-1 core measures.  Our arguments have fallen on deaf ears. 

We have waited patiently for years in hopes that the guidelines would improve, but they have not.  The 2018 SSC update is actually worse than prior guidelines, requiring the initiation of antibiotics and 30 cc/kg fluid bolus within merely sixty minutes of emergency department triage (16).  These recommendations are arbitrary and dangerous.  They will likely cause hasty management decisions, inappropriate fluid administration, and indiscriminate use of broad-spectrum antibiotics.  We have been down this path before with other guidelines that required antibiotics for pneumonia within four hours, a recommendation that harmed patients and was eventually withdrawn (17).

It is increasingly clear that the SSC guidelines are an impediment to providing the best possible care to our septic patients.  The rigid framework mandated by SSC doesn’t help experienced clinicians provide tailored therapy to their patients.  Furthermore, the hegemony of these guidelines prevents other societies from developing better guidelines.

We are therefore petitioning for the retirement of the SSC guidelines.  In its place, we would call for the development of separate sepsis guidelines by the United States, Europe, ANZICS, and likely other locales as well.  There has been a monopoly on sepsis guidelines for too long, leading to stagnation and dogmatism.  We would hope that these new guidelines are written by collaborations of the appropriate professional societies, based on the highest evidentiary standards.  The existence of several competing sepsis guidelines could promote a diversity of opinions, regional adaptation, and flexible thinking about different approaches to sepsis. 

We are disseminating an international petition that will allow clinicians to express their displeasure and concern over these guidelines.  If you believe that our septic patients deserve more evidence-based guidelines, please stand with us.  

Sincerely,

Scott Aberegg MD MPH
Jennifer Beck-Esmay MD
Steven Carroll DO MEd
Joshua Farkas MD
Jon-Emile Kenny MD
Alex Koyfman MD
Michelle Lin MD
Brit Long MD
Manu Malbrain MD PhD
Paul Marik MD
Ken Milne MD
Justin Morgenstern MD
Segun Olusanya MD
Salim Rezaie MD
Philippe Rola MD
Manpreet Singh MD
Rory Speigel MD
Reuben Strayer MD
Anand Swaminathan MD
Adam Thomas MD
Lauren Westafer DO MPH
Scott Weingart MD

References
  1. Eichacker PQ, Natanson C, Danner RL.  Surviving Sepsis – Practice guidelines, marketing campaigns, and Eli Lilly.  New England Journal of Medicine  2006; 16: 1640-1642.
  2. Pepper DJ, Jaswal D, Sun J, Welsch J, Natanson C, Eichacker PQ.  Evidence underpinning the Centers for Medicare & Medicaid Services’ Severe Sepsis and Septic Shock Management Bundle (SEP-1): A systematic review.  Annals of Internal Medicine 2018; 168:  558-568. 
  3. Finfer S.  The Surviving Sepsis Campaign:  Robust evaluation and high-quality primary research is still needed.  Intensive Care Medicine  2010; 36:  187-189.
  4. Salluh JIF, Bozza PT, Bozza FA.  Surviving sepsis campaign:  A critical reappraisal.  Shock 2008; 30: 70-72. 
  5. Eichacker PQ, Natanson C, Danner RL.  Separating practice guidelines from pharmaceutical marketing.  Critical Care Medicine 2007; 35:  2877-2878. 
  6. Hicks P, Cooper DJ, Webb S, Myburgh J, Sppelt I, Peake S, Joyce C, Stephens D, Turner A, French C, Hart G, Jenkins I, Burrell A.  The Surviving Sepsis Campaign:  International guidelines for management of severe sepsis and septic shock: 2008.  An assessment by the Australian and New Zealand Intensive Care Society.  Anaesthesia and Intensive Care 2008; 36: 149-151.
  7. Rivers ME et al.  Early goal-directed therapy in the treatment of severe sepsis and septic shock.  New England Journal of Medicine 2001; 345: 1368-1377.
  8. Wenzel RP, Edmond MB.  Septic shock – Evaluating another failed treatment.  New England Journal of Medicine 2012; 366:  2122-2124.  
  9. Savel RH, Munro CL.  Evidence-based backlash:  The tale of drotrecogin alfa.  American Journal of Critical Care  2012; 21: 81-83. 
  10. Dellinger RP, Levy MM, Carlet JM et al.  Surviving sepsis campaign:  International guidelines for management of severe sepsis and septic shock:  2008.  Intensive Care Medicine 2008; 34:  17-60. 
  11. Allison MG, Schenkel SM.  SEP-1:  A sepsis measure in need of resuscitation?  Annals of Emergency Medicine 2018; 71: 18-20.
  12. Barochia AV, Xizhong C, Eichacker PQ.  The Surviving Sepsis Campaign’s revised sepsis bundles.  Current Infectious Disease Reports 2013; 15:  385-393. 
  13. Marik PE, Malbrain MLNG.  The SEP-1 quality mandate may be harmful: How to drown a patient with 30 ml per kg fluid!  Anesthesiology and Intensive Therapy 2017; 49(5) 323-328.
  14. Faust JS, Weingart SD.  The past, present, and future of the centers for Medicare and Medicaid Services quality measure SEP-1:  The early management bundle for severe sepsis/septic shock.  Emergency Medicine Clinics of North America 2017; 35:  219-231.
  15. Marik PE.  Surviving sepsis:  going beyond the guidelines.  Annals of Intensive Care 2011; 1: 17.
  16. Levy MM, Evans LE, Rhodes A.  The surviving sepsis campaign bundle:  2018 update.  Intensive Care Medicine.  Electronic publication ahead of print, PMID 29675566.
  17. Kanwar M, Brar N, Khatib R, Fakih MG.  Misdiagnosis of community-acquired pneumonia and inappropriate utilization of antibiotics: side effects of the 4-h antibiotic administration rule.  Chest 2007; 131: 1865-1869.

Tuesday, February 23, 2016

Much Ado About Nothing? The Relevance of New Sepsis Definitions for Clinical Care Versus Research

What's in a name?  That which we call a rose, by any other name would smell as sweet. - Shakespeare, Romeo and Juliet Act II Scene II

The Society of Critical Care Medicine is meeting this week, JAMA devoted an entire issue to sepsis and critical illness, and my twitter feed is ablaze with news of release of a new consensus definition of sepsis.  Much laudable work has been done to get to this point, even as the work is already generating controversy (Is this a "first world" definition that will be forced upon second and third world countries where it may have less external validity?  Why were no women on the panel?).  Making the definition of sepsis more reliable, from a sensitivity and specificity standpoint (more accurate) is a step forward for the sepsis research enterprise, for it will allow improved targeting of inclusion criteria for trials of therapies for sepsis, and better external validity when those therapies are later applied in a population that resembles those enrolled.  But what impact will/should the new definition have on clinical care?  Are the-times-they-are-a-changing?

Diagnosis, a fundamental goal of clinical medicine is important for several reasons, chief among them:

  1. To identify the underlying cause of symptoms and signs so that treatments specific to that illness can be administered
  2. To provide information on prognosis, natural history, course, etc for patients with or without treatment
  3. To reassure the physician and patients that there is an understanding of what is going on; information itself has value even if it is not actionable
Thus redefining sepsis (or even defining it in the first place) is valuable if it allows us to institute treatments that would not otherwise be instituted, or provides prognostic or other information that is valuable to patients.  Does it do either of those two things?

Friday, May 1, 2015

Is There a Baby in That Bathwater? Status Quo Bias in Evidence Appraisal in Critical Care

"But we are not here concerned with hopes and fears, only the truth so far as our reason allows us to discover it."  -  Charles Darwin, The Descent of Man

Status quo bias is a cognitive decision making bias that leads to decision makers' preference for the choice represented by the current status quo, even when the status quo is arbitrary or irrelevant.  Decision makers tend to perceive a change from the status quo as a loss and therefore their decisions are biased toward the status quo.  This can lead to preference reversals when the status quo reference frame is changed.  The status quo can be debiased using a reversal test, i.e., manipulating the status quo either experimentally or via thought experiment to consider a change in the opposite direction.  If reluctance to change from the status quo exists in both directions, status quo bias is likely to exist.

My collaborators Peter Terry, Hal Arkes and I reported in a study published in 2006 that physicians were far more likely to abandon a therapy that was status quo or standard therapy based on new evidence of harm than they were to adopt an identical therapy based on the same evidence of benefit from a fictitious RCT (randomized controlled trial) presented in the vignette.  These results suggested that there was an asymmetric status quo bias - physicians showed a strong preference for the status quo in the adoption of new therapies, but a strong preference for abandoning the status quo when a standard of care was shown to be harmful.  Two characteristics of the vignettes used in this intersubject study deserve attention.  First, the vignettes described a standard or status quo therapy that had no support from RCTs prior to the fictitious one described in the vignette.  Second, this study was driven in part by what I perceived at the time was a curious lack of adoption of drotrecogin-alfa (Xigris), with its then purported mortality benefit and associated bleeding risk.  Thus, our vignettes had very significant trade-offs in terms of side effects in both the adopt and abandon reference frames.  Our results seemed to explain s/low uptake of Xigris, and were also consistent with the relatively rapid abandonment of hormone replacement therapy (HRT) after publication of the WHI, the first RCT of HRT.

Saturday, October 11, 2014

Enrolling Bad Patients After Good: Sunk Cost Bias and the Meta-Analytic Futility Stopping Rule

Four (relatively) large critical care randomized controlled trials were published early in the NEJM in the last week.  I was excited to blog on them, but then I realized they're all four old news, so there's nothing to blog about.  But alas, the fact that there is no news is the news.

In the last week, we "learned" that more transfusion is not helpful in septic shock, that EGDT (the ARISE trial) is not beneficial in sepsis, that simvastatin (HARP-2 trial) is not beneficial in ARDS, and that parental administration of nutrition is not superior to enteral administration in critical illness.  Any of that sound familiar?

I read the first two articles, then discovered the last two and I said to myself "I'm not reading these."  At first I felt bad about this decision, but then that I realized it is a rational one.  Here's why.

Monday, May 19, 2014

Sell Side Bias and Scientific Stockholm Syndrome: A Report from the Annual Meeting of the American Thoracic Society

What secrets lie inside?
Analysts working on Wall Street are sometimes categorized as working on either the "buy side" or the "sell side" depending on whether their firm is placing orders for stocks (buy side, such as institutional investors for mutual funds) or filling orders for stocks (sell side, which makes commissions on stock trades).  Sell side bias refers to any tendency for the sell side to "push" stocks via overly optimistic ratings and analyses.

Well, I'm at the American Thoracic Society (ATS) meeting in San Diego right now, and it certainly does feel like people - everyone - is trying to sell me something.  From the giant industry sponsored banners, to the emblazoned tote bags, to the bags of propaganda left at my hotel room door every morning, to the exhibitor hall filled with every manner of new and fancy gadgets (but closed to cameras), to the investigators themselves, everybody is trying to convince me to buy (or prescribe) something.  Especially ideas.  Investigators have a promotional interest in their ideas.  And they want you and me to buy into their ideas.  I have become convinced that investigators without industry ties (that dying breed) are just about as susceptible to sell side bias as those with industry ties.  Indeed, I have also noted that the potential consumer of many of the ideas himself seems biased - he wants things to work, too, and he has a ready explanation for why some ideas didn't pan out in the data (see below).  It's like an epidemic of scientific Stockholm Syndrome.

The first session I attended was a synopsis of the SAILS trial by the ARDSnet investigators, testing whether use of a statin, rosuvastatin, in patients with sepsis-incited lung injury would influence 60 day mortality.  The basis of this trial was formed by observational associations that patients on statins had better outcomes in this, that, and the other thing, including sepsis.  If you are not already aware of the results, guess whether rosuvastatin was beneficial in this study.

Saturday, April 26, 2014

Dear SIRS: Your Septic System Stinks

I perused with interest the April 2nd JAMA article on the temporal improvement in severe sepsis outcomes in Australia and New Zealand (ANZ) by Kaukonen et al this week.  Epidemiological studies like this remind me why I'm so fond of reading reports of RCTs:  because they're so much easier to think about.  Epidemiological studies have so many variables, measured and unmeasured, and so much confounding you have to consider. I spent at least five hours poring over the ANZ report, and then comparing it to the recent NEJM article about improved diabetes complications between 1990 and 2010, which is similar, but a bit more convincing (perhaps the reason it's in the NEJM).

I was delighted that the authors of the ANZ study twice referenced our delta inflation article and that the editorialists agree with the letter I wrote to AJRCCM last year advocating composite morbidity outcomes in trials of critical illness.  These issues dovetail - we have a consistent track record of failure to demonstrate mortality improvements in critical care, while we turn a blind eye to other outcomes which may be more tractable and which are often of paramount concern to patients.

Sunday, March 23, 2014

Lost Without a MAP: Blood Pressure Targets in Septic Shock

Another of the critical care articles published early online at www.nejm.org last week was this trial of High versus Low Blood-Pressure Target in Patients with Septic Shock.  In this multicenter, open-label trial, the authors enrolled 776 patients in France and randomized them to a target MAP (mean arterial pressure) of 65-70 mm Hg (low target) versus 80-85 (high target).  The hypothesis is that a higher pressure, achieved through vasopressor administration, will improve 28-day mortality.  If you don't already know the result, guess if the data from this trial support or confirm the hypothesis (the trial had 80% power to show a 10% absolute reduction in mortality).

Thursday, March 20, 2014

Sepsis Bungles: The Lessons of Early Goal Directed Therapy

On March 18th, the NEJM published early online three original trials of therapies for the critically ill that will serve as fodder for several posts.  Here, I focus on the ProCESS trial of protocol guided therapy for early septic shock.  This trial is in essence a multicenter version of the landmark 2001 trial of Early Goal Directed Therapy (EGDT) for severe sepsis by Rivers et al.  That trial showed a stunning 16% absolute reduction in mortality in sepsis attributed to the use of a protocol based on physiological goals for hemodynamic management.  That absolute reduction in mortality is perhaps the largest for any therapy in critical care medicine.  If such a reduction were confirmed, it would make EGDT the single most important therapy in the field.  If such reduction cannot be confirmed, there are several reasons why the Rivers results may have been misleading:

There were other concerns about the Rivers study and how it was later incorporated into practice, but I won't belabor them here.  The ProCESS trial randomized about 1350 patients among three groups, one simulating the original Rivers protocol, one to a modified Rivers protocol, and one representing "standard care" that is, care directed by the treating physician without a protocol.  The study had 80% power to demonstrate a mortality reduction of 6-7%.  Before you read further, please wager, will the trial show any statistically significant differences in outcome that favor EGDT or protocolized care?

Monday, November 18, 2013

Dead in the Water: Colloids versus Crystalloids for Fluid Resuscitation in the ICU

It is a valid question:  at what point has a concept been tested ad infinitum such that further testing is not worthwhile?  There are at least three reasons why additional study of a concept may not be justified:

  1. Because the prior probability of success is so low (based on extant trials) that a subsequent trial is unlikely to influence the posterior probability that any success represents the truth.  (This is a Bayesian or meta-analytic worldview.)
  2. Because the low probability of success does not justify the expense of additional trials
  3. Because the low probability of success violates bioethical precepts mandating that trials must have added value for patients and society
And so we have, in the November 6th edition of JAMA, the CRISTAL trial of colloids versus crystalloids for resuscitation in the ICU.  As is customary, I will leave it to interested readers to peruse the manuscript for details.  My task here is to provide some background and nuance.

Saturday, October 12, 2013

Goldilocks Meets Walter White in the ICU: Finding the Temperature (for Sepsis and Meningitis) that's Just Right

In the Point/Counterpoint  section of the October issue of Chest, two pairs of authors spar over whether fever should be controlled in sepsis by either pharmacological or external means.  Readers of this blog may recall this post wherein I critically appraised the Schortgen article on external cooling in septic shock that was in AJRCCM last year.  Apparently that article made a more favorable impression on some practitioners than it did on me, as the proponents of cooling in the Chest piece hang their hats on this article (and their ability to apply physiological principles to medical therapeutics).  (My gripes with the Schortgen study were many, including a primary endpoint that was of little value, cherrypicking the timing of the secondary mortality endpoint, and the lack of any biological precedent for manipulation of body temperature improving mortality in any disease.)

Reading the Point and Counterpoint piece (in addition to an online first article in JAMA describing a trial of induced hypothermia in severe bacterial meningitis - more on that later) allowed me to synthesize some ideas about the epistemology (and psychology) of medical evidence and its evaluation that I have been tossing about in my head for a while.  Both the proponent pair and the opponent pair of authors give some background physiological reasoning as to why fever may be, by turns, beneficial and detrimental in sepsis.  The difference, and I think this is typical, is that the proponents of fever reduction:  a.) seem much more smitten by their presumed understanding of the underlying physiology of sepsis and the febrile response; b.) focus more on minutiae of that physiology; c.) fail to temper their faith in application of physiological principles with the empirical data; and d.) grope for subtle signals in the empirical data that appear to rescue the sinking hypothesis.

Sunday, March 24, 2013

Why Most Clinical Trials Fail: The Case of Eritoran and Immunomodulatory Therapies for Sepsis

The experimenter's view of the trees.
The ACCESS trial of eritoran in the March 20, 2013 issue of JAMA can serve as a springboard to consider why every biological and immunomodulatory therapy for sepsis has failed during the last 30 years.  Why, in spite of extensive efforts spanning several decades have we failed to find a therapy that favorably influences the course of sepsis?  More generally, why do most clinical trials, when free from bias, fail to show benefit of the therapies tested?

For a therapeutic agent to improve outcomes in a given disease, say sepsis, a fundamental and paramount precondition must be met:  the agent/therapy must interfere with part of the causal pathway to the outcome of interest.  Even if this precondition is met, the agent may not influence the outcome favorably for several reasons:
  • Causal pathway redundancy:  redundancy in causal pathways may mitigate the agent's effects on the downstream outcome of interest - blocking one intermediary fails because another pathway remains active
  • Causal factor redundancy:  the factor affected by the agent has both beneficial and untoward effects in different causal pathways - that is, the agent's toxic effects may outweigh/counteract its beneficial ones through different pathways
  • Time dependency of the causal pathway:  the agent interferes with a factor in the causal pathway that is time dependent and thus the timing of administration is crucial for expression of the agent's effects
  • Multiplicity of agent effects:  the agent has multiple effects on multiple pathways - e.g., HMG-CoA reductase inhibitors both lower LDL cholesterol and have anti-inflammatory effects.  In this case, the agent may influence the outcome favorably, but it's a trick of nature - it's doing so via a different mechanism than the one you think it is.

Thursday, May 24, 2012

Fever, external cooling, biological precedent, and the epistemology of medical evidence

It is rare occasion that one article allows me to review so many aspects of the epistemology of medical evidence, but alas Schortgen et al afforded me that opportunity in the May 15th issue of AJRCCM.

The issues raised by this article are so numerous that I shall make subsections for each one. The authors of this RCT sought to determine the effect of external cooling of febrile septic patients on vasopressor requirements and mortality. Their conclusion was that "fever control using external cooling was safe and decreased vasopressor requirements and early mortality in septic shock." Let's explore the article and the issues it raises and see if this conclusion seems justified and how this study fits into current ICU practice.

PRIOR PROBABILITY, BIOLOGICAL PLAUSIBILITY, and BIOLOGICAL PRECEDENTS

These are related but distinct issues that are best considered both before a study is planned, and before its report is read. A clinical trial is in essence a diagnostic test of a hypothesis, and like a diagnostic test, its influence on what we already know depends not only on the characteristics of the test (sensitivity and specificity in a diagnostic test; alpha and power in the case of a clinical trial) but also on the strength of our prior beliefs. To quote Sagan [again], "extraordinary claims require extraordinary evidence." I like analogies of extremes: no trial result is sufficient to convince the skeptical observer that orange juice reduces mortality in sepsis by 30%; and no evidence, however cogently presented, is sufficient to convince him that the sun will not rise tomorrow. So when we read the title of this or any other study, we should pause to ask: What is my prior belief that external cooling will reduce mortality in septic shock? That it will reduce vasopressor requirements?

Thursday, July 9, 2009

No Sham Needed in Sham Trials: Polymyxin B Hemoperfusion in Abdominal Septic Shock (Alternative Title: How Meddling Ethicists Ruin Everything)

This a superlative article to jab at to demonstrate some interesting points about randomized controlled trials that have more basis in hope than reason and whose very design threatens to invalidate their findings: http://jama.ama-assn.org/cgi/content/abstract/301/23/2445?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=polymyxin&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT . Because endotoxin has an important role in the pathogenesis of gram-negative sepsis, there has been interest in interfering with it or removing it in the hopes of abating the untoward effects of the sepsis inflammatory cascade. Learning from previous experiences/studies (e.g., http://content.nejm.org/cgi/content/abstract/324/7/429 ) that taking a poorly defined and heterogenous illness (namely sepsis) and using therapy that is expected to work in only a subset of patients with the illness (gram-negative source), the authors chose to study abdominal sepsis because they expected that the majority of patients will have gram-negatives as a causative or contributory source of infection. They randomized such patients to receive standard care (not well defined) or the insertion of a dialysis catheter with subsequent hemoperfusion over a Polymyxin B impregnated surface because this agent is known to adsorb endotoxin. The basic biological hypothesis is that removing the endotoxin in this fashion will cause amelioration of the untoward effects of the sepsis inflammatory cascade in such a way as to improve blood pressure, other phyisological parameters, and hopefully, mortality as well. There is reason to begin one's reading of this report with robust skepticism. The history of modern molecular medicine, for well over 25 years, has been polluted with the vast detritus of innumerable failed sepsis trials founded on hypotheses related to modulation of the sepsis cascade. During this period, only one agent has been shown to be efficacious, and even its efficacy remains highly doubtful to perhaps the majority of intensivists (myself excluded; see: http://content.nejm.org/cgi/content/abstract/344/10/699 ).


Mortality was not the primary endpoint in this trial, but rather was used for the early stopping rule. Even though I am currently writing an article suggesting that mortality may not be a good endpoint for trials of critical illness, this trial reminds me why the critical care community has selected this endpoint as the bona fide gold standard. Who cares if this invasive therapy increases your MAP from the already acceptable level of ~77mmHg to the supertarget level of 86? Who cares if it reduces your pressor requirements? Why would a patient, upon awakening from critical illness, thank his doctors for inserting a large dialysis catheter in him to keep his BP a little higher than it otherwise would have been? Why would he rather have a giant hole in his neck (or worse - GROIN!) than a little more levophed? If it doesn't save your life or make your life better when you recover, why do you care? We desperately need to begin to study concepts such as "return to full functionality at three (or six) months" or "recovery without persistent organ failures at x,y,z months". (This latter term I would define as not needing ongoing therapy for the support of any lingering organ failure after critical illness [that did not exist in the premorbid state], such as oxygen therapy, tracheostomy, dialysis, etc.). Should I be counted as a "save" if my existence after the interventions of the "saviors" is constituted by residence in a nursing home dependent on others for my care with waxing and waning lucidity? What does society think about these questions? We should begin to ask.

And we segue to the stopping issue which I find especially intriguing. Basing the stopping rule on a mortality difference seems to validate my points above, namely that the primary endpoint (MAP) is basically a worthless one - if it were not, or if it were not trumped by mortality, why would we not base stopping of the trial on MAP? (And if this is a Phase II or pilot trial, it should be named accordingly, methinks.) This small trial was stopped on the basis of a mortality difference significant at P=0.026 with the stopping boundary at P<0.029. I will point out again on this blog for those not familiar with it this pivotal article warning of the hazards of early stopping rules (http://jama.ama-assn.org/cgi/content/abstract/294/17/2203 ). But here's the real rub. When they got these results at the first and only planned interim analysis, (deep breath), they consulted with an ethicist. The ethicist said that it is unethical to continue the trial because to do so would be to deny this presumably effective therapy to the control group. But does ANYONE in his or her right state of mind agree that this therapy is effective on the basis of these data? And if these data are not conclusive, does not that condemn future participants in a future trial to the same unfair treatment, namely randomization to placebo? Does not stopping the trial early just shift the burden to other people? It does worse. It invalidates to large degree the altruistic motives of the participants (or their surrogates) in the current trial because stopping it early invalidated it scientifically (per the above referenced article) and because stopping it early necessitates the performance of yet another larger trial where participants will be randomized to placebo, and which, it is fair to suspect, will demonstrate this therapy to be useless, which is tantamount to harmful in the net because of the risk of catheters and wasted resources in performing yet another trial. Likewise, if we assume that this therapy IS beneficial, stopping it has reduced NET utility to current participants, because now NOBODY is receiving the therapy. So, from a consequentialist or utilitarian standpoint, overall utility is reduced and net harm has resulted from stopping the trial. What if the investigators of this trial had made it more scientifically valid from the outset by using a sham hemoperfusion device (an approach that itself would have caused an ethical maelstrom)? And what if the sham group proved superior in terms of mortality - would the ethicists have argued for stopping the trial because continuing it would mean depriving patients of sham therapy? Would there have been a call for providing sham therapy to all patients with surgically intervened abdominal sepsis? I write this with my tongue in my cheek, but the ludicrousness of it does seem to drive home the point that the premature stopping of this trial is neither ethically clear-cut nor obligatory, and that from a utilitarian standpoint, net negative utility (for society and for participants - for everyone!) has resulted from this move. And that segues me to the issue of sham procedures. It is abundantly obvious that patients with a dialysis catheter inserted for this trial (probably put in by an investigator, but not stated in the manuscript) will be likely to receive more vigilant care. This is the whole reason that protocols were developed in critical care research, as a result of the early ECMO trials (Morris et al 1994) where it was recognized that you would have all sorts of confounding by the inability to blind treating physicians in such a study. While it is not feasible to blind an ECMO study, the investigators of this study do little to convince us that blinding was not possible and feasible, and they make light of the differences in care that may have resulted from lack of blinding. Moreover, they do not report on the use of protocols for patient care that may/could have minimized the impact of lack of blinding, and in a GLARING omission, they do not describe fluid balance in these patients, a highly discretionary aspect of care that clearly could have influenced the primary outcome and which could have been differential between groups because of the lack of blinding and sham procedures. Unbelievable! (As an afterthought, even the mere increased stimulation [tactile, auditory, or visual] of patients in the intervention group, by more nursing presence or physician presence in the room may have led to increases in blood pressure.) There are also some smaller points, such as the fact that by my count 10 patients (not accounting for multiple organisms) in the intervention group had gram positive or fungal infections making it difficult to imagine how the therapy could have influenced these patients. What if patients without gram-negative organisms isolated are excluded from the analysis? Does the effect persist? What is the p-value for mortality then? And that point segues me to a final point - if our biologically plausible hypothesis is that reducing endotoxin levels with this therapy leads to improvements in parameters of interest, why, for the love of God, did we not measure and report endotoxin levels and perform secondary analyses of the effect of the therapy as a function of endotoxin levels and also report data on whether these levels were reduced by the therapy, thus supporting the most fundamental assumption of the biological hypothesis upon which the entire study is predicated?