The Quest For Zero Infections: A Fool’s Mission?

flying cadeuciiJoyce is sick.  I am in the intensive care unit, peering at vital parameters that glow on the screen above her bed.  My eyes linger on those numbers because it is easier than looking at her.  A fever rages, her core temperature reads 103.4 degrees.  Her white hair is plastered on her forehead with sweat, and a tube to help her breathe emerges from her mouth and heads to a ventilator that angrily tweets a musical alarm every few minutes.  Her breathing is painfully obvious.  Her stomach moves paradoxically inward on every breath, and I can see the muscles in her neck tense with the effort of every breath.  Mercifully, her eyes are closed.  A nurse walks in and starts to change a bag of fluids that is hanging by her bed.  I follow the flexible plastic tubing that arises from the bag to an infusion pump, and then to a catheter that snakes under a see-through dressing underneath Joyce’s left collarbone.  I ask the nurse about how long the catheter has been in place…’3 days’…I’m told.  I mutter about the possibility of a central line infection – the dreaded central line-associated blood stream infection (CLABSI).  The nurse shakes her head, and tells me – “we don’t get those anymore”.

CLABSIs are ground zero in the war on preventing patient harm.  The story entered the mainstream consciousness in the lyrical words of Atul Gawande in the New Yorker in 2007.  There he told a story of an unlikely Superman in the form of a critical care intensivist named Peter Pronovost. Dr. Pronovost was waging war against infections from these nefarious central lines that were saving and killing patients at the same time.  He published a landmark study in the New England Journal of Medicine that used an evidence-based intervention to dramatically reduce infection rates in the intensive care unit.  Some form of the implementation bundle that worked for Dr. Pronovost soon found itself in ICUs everywhere.  Dramatic reductions in CLABSI rates followed.

The remarkable part about this feel good story is that it seemed so easy.  The ICU I was in had seemingly reproduced this success as well.  I spoke to nurse after nurse who noted that CLABSI’s were fairly rare events at this point.  Everyone had a different theory about how this happened.  Some attributed this to the full barrier sterile technique used for line insertion, others to the limitations put in place to draw blood from central line catheters, while others felt it was the maintenance of the catheters after they were placed.  Regardless, everyone had CLABSI on the brain.  The government had mandated that hospitals report their CLABSI rates, and with this, hospital resources to blot out this particular black spot were committed in earnest.  It should come as no surprise that infection rates would drop.  The size of the effect impressed me.  Hospitals, in my experience, are like large lumbering elephants.  It usually takes three forms, five signatures, and at the end of it all, I am told HIPAA won’t allow it.  No matter what it is.

In 1958, Hawthorne Works, a Western Electric factory outside of Chicago commissioned a study to see if their workers would become more productive in higher or lower levels of light.  The workers’ productivity improved when changes were made, but slumped when the study was over.  It was suggested the productivity gains were made because the workers were being observed. This has come to be known as the Hawthorne effect.  Not surprisingly the simple act of measuring, observing or testing has an effect on the performance of subjects.

There was no doubt that implementing a variety of maneuvers to reduce infections was having an impact, but this is not the whole story. In this particular ICU, for instance, I noticed that blood cultures were now rarely drawn from the central lines themselves.  They were now drawn peripherally.  This means hunting for a vein to thread a needle into to get a culture.  It was so much easier to take an empty syringe, hook it up to a catheter that was sitting in a vein and draw back 10 ml of blood.  The patient didn’t have to be stuck with a needle and a nurse/physician didn’t have to spend precious minutes hunting for a vein in a critically ill patient whose veins are either collapsed or buried in tissue laden with fluid.  Requiring peripheral cultures, though, does make plenty of clinical sense.

Cultures from catheters have a high false positive rate: organisms may grow that are colonizing the catheter but not causing an infection.  Deciding between the two – colonization or infection – can be challenging and is many times a clinical decision.  The CDC criteria for CLABSI in this regard is monolothic: any blood stream infection with a pathogenic organism counts against you.  Secondly, the act of collecting blood from a catheter is thought to raise the risk of introducing micro-organisms into the blood stream, and causing an infection.  These two points have been known for some time, but it was the specter of public reporting of these infections that really pushed hospitals to move in a systematic fashion to develop rigid protocols about cultures being drawn from central lines.  I applaud this new found fastidiousness with regard to cultures, but it does, however, make comparisons of infection rates somewhat challenging.  How much of the decline in infection rates is secondary to a more restrictive policy related to ordering blood cultures?  It is hard to know, and even Pronovost’s landmark study cannot escape from the bias inherent in performing a non-randomized study that in essence tracked infection rates over time.  Regardless of the size of the true effect, Pronovost’s accomplishment cannot be understated.  I can think of little that has been as clinically impactful in as short of a time.  To get hospital CEOs, CMO’s, infection control committees, nurses, technicians and physicians on the same page with regards to evidence based practices for line infections is a true tour de force.

Of course, a hard lesson I learned after a peanut better and jelly sandwich orgy applies here too – there can be too much of a good thing.  Pronovost started on a mission to reduce infections, but yet that is not what we try to do now.  Our current mission statement is to get to zero.  CLABSI’s have become the poster child for ‘preventable harm’,  a phrase that does not just imply,  but unabashedly states that any infection associated with a central line can be prevented.  Patients and stakeholders have carried this torch forward. Medicare has pushed forward with policies that would withhold reimbursement for any CLABSI’s, because of course, they are all deemed preventable.

The evidence for a zero is non-existent.  Pronovost’s study reduced infection rates a remarkable 66%.

2012 study provocatively titled: Zero risk for central line-associated blood stream infection: Are we there yet? found that we were not there yet.  The study based in 37 ICUs in South Wales sought to identify the longest time a central line could stay free of infection with another ‘insertion intervention bundle’.  The authors reported a significant reduction in rates of infection with their prevention bundle, but importantly found no catheter dwell time that was associated with zero risk.  It should not take a study to say this.  In today’s non-Star Trek world, the reality of critical care medicine frequently involves the insertion of central line catheters that are life saving.  These catheters are placed, not in the vacuum of space into sterile objects, but rather within the milieu of a hospital teeming with pathogenic organisms, and into patients that are far from sterile.  Our attempts to sterilize the human environment is an exercise in reducing the burden of micro-organisms, not eliminating them.

Tying reimbursement to an impossible goal places inordinate pressures on hospitals, which have consequences that are unintended, but quite predictable.  The response of hospitals and their staff takes many forms, and I have already written about the new found parsimony in blood cultures being drawn from central lines.  Other maneuvers are less sanguine.  A study done to compare infection control practitioners  to a standardized computer algorithm had disturbing results.  The medical center that had the lowest rate of central line infections as judged by infection control practitioners (2.4/1000 central-line days) had the highest rate by the standardized computer algorithm (12.6/1000 central-line days).  The study authors concluded that the variability of infection rates seen when compared to a reference standard suggests significant variation in the application of standard CLABSI definitions.  It would appear that the CLABSI definition was being applied in a subjective fashion to report rates much lower than an objective standard.  Welcome to a world that tells you what you want to hear.

The narrative that surrounds the noble sounding ‘prevention of harm’ strips meaning from the very phrase when applied in such a liberal, incoherent fashion. The reality is that patients arrive at hospitals and critical care units in extremis.  In that hospital room we struggle to make Joyce whole again.  It is a struggle we may not win because the very interventions we use to save a life can also take a life. The fervent hope of everyone in Joyce’s room is that on balance the benefits of the interventions taken are greater than the risks.  Over time, mortality rates have fallen in intensive care units – a fact that is remarkable given that patients in ICUs today are sicker than ever.  This fall in mortality is driven by progress in treatment of underlying disease states, as well as improvement of processes in medicine that predates ProPublica-style transparency and ‘performance’-based reimbursement.

Remarkably, yet predictably, the current iteration of ‘transparency’ combined with unrealistic expectations may be doing more harm than good.




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5 replies »

  1. The reduction of CLABSI is a genuine victory of safety advocates, and full credit to Pronovost. But like most things in life, the law of diminishing returns kicks in, and sterilizing the last atom will be extremely costly, largely unsuccessful, and perhaps even counterproductive.

  2. Seems to be what folks are incentivized to do..I don’t advocate for no testing, but is it too much to ask for realistic expectations?

  3. Exactly. Now if only the ven diagram of policy makers and clinicians who take care of patients connected. What a world that would be.

  4. I have an ancient horse that recently quit eating. Concerned, because it was near the beginning of the holiday weekend, I called to have a vet come out to check her. He reported back with a message that he had looked high and low and found nothing until he did a fecal test which showed extensive parasitic worm infestation.
    When I spoke with him I was concerned that my worming schedule was inappropriate or not giving the right meds. He assured me that I was doing nothing wrong, that she was an old horse with declining health and a diminished immune system.
    So, despite adequate, routine care, my aging horse developed a worm infestation.
    While I heartily agree with good routine care and hygiene and meticulous attention to sterile technique, I think a 0% CLABSI rate is an impossibility. And anyone who takes care of patients on a regular basis should know this.