Stringing together a few rules of thumb

American ER Doc Gone Walkabout Episode 030

Let’s go back a few decades:  a person presents to the ER with signs of sepsis and a low blood pressure.  We evaluate the neck veins, listen to the lungs for crackles, maybe evaluate the BP response to Trendelenberg positioning.  Might even insert a central line and measure pressures with an old-school fluid filled manometer (or, just hold up some IV tubing attached to the CVC, and guesstimate the filling pressures – I did that a lot of times).  Not many protocols or pathways around, but many of us had some implicit internalized rules as to what we’d do.

With time and evidence and technology things have been more codified with the formal definition of sepsis and SIRS and whether it is severe.  We’ve had defined evidence of volumes to give and endpoints to achieve.  We’ve got better technology:  continuous electronic CVP pressure monitoring, as well as alternative and better measures – ultrasonographic, for instance – of volume tolerance and volume responsiveness.  (Don’t give up on me yet:  I have indeed read ProCESS and will have a comment at the end.)

Surviving Sepsis Campaign provides guidelines, and many ED’s have even more restrictive protocols.  These protocols allow even the untrained (kinda like me using a cookbook – though that may be an inept comparison, because even with detailed instructions, when I try to cook, often the first clue that dinner is ready is the blare of the smoke alarm) to follow a reasonable path to effective sepsis treatment.  For the more knowledgeable, a protocol saves time, helps to avoid oversight of important steps even when multitasking a busy department, or when tired or distracted.

The protocol may provide backup when dealing with recalcitrant consultants (“I know, and you know, that this patient is intoxicated, homeless, and smelly – but, he is also sick with disease x: your department and the ED have agreed a plan as to how these patients will be managed.  I’ve done my part, and now it’s time for you to do your part.  Thanks for your kind assistance.”)

The best, and most experienced clinicians may vary a bit from the clinical pathway (I hope that some degree of freedom is allowed).  Think of it as a glidepath being followed by a pilot landing a plane:  if you keep your airplane right on the glide path, you will arrive safely at the end of the runway.  But, the most experienced pilot might know that with the present winds, he’ll lose airspeed and altitude rapidly as he crosses the upcoming ridge – so he will let his plane stay a bit high on the glide path and allow it to drift down to the correct line as it crosses the ridge.  Without needing any abrupt adjustments to regain the path.  Smoother, but not strictly necessary.)

So, our most adept clinicians might modify step 1:  I’ll give volume until I hit one of several measures (depending on how sick, how available insertion of a CVC, how busy, etc.) – CVP, IVC size and collapsibility, response to leg raising, pulse pressure variability, whatever.  I’ll limit chloride ( to avoid worsening acidosis, and to protect renal function) and add albumin if giving lots of volume.  I don’t want to deal, in a couple days, with all that extra volume – now in the lungs – so, if my name is Marik, I’ll shrink the tank while filling it, by early addition of noradrenaline (norepi for the Yanks).

I’ve argued that we use RoT’s as shorthand or heuristic for experience and/or EBM.  And, that more often than not, they are implicit: I’m caring for an ankle injury which was suffered by stepping on uneven ground while my attention was distracted.  It’s unlikely that the cardiovascular or neurologic exam will demonstrate a cause for the fall, and I will therefore either not do the exam, or will do the exam in an efficient way.  I don’t have an explicit rule, but I’ve got that little implicit summary of all my training and experience that says, examine the ankle, not much else, and then get on with it.

Just imagine that the ankle injury was sustained by someone walking on the beach, looking at some gentleman wearing budgie smugglers, and wondering if it was Tony Abbott  (OK, Yanks, there are just so many things that you might not understand about that reference:  Tony Abbott( not related to me) is Oz’s PM, well known for news photo of him wearing inappropriate beach wear – Speedo’s to be precise – known to some as “Budgie Smuggler’s”, Budgies being an Aussie term for a small bird, and we’ll leave it to your (presumably filthy) imagination as to why wearing a Speedo might cause one to think that you were smuggling a couple of Budgies in it).

BTW, for the yanks, the little hat has no suggestion of Tony being Orthodox Jewish:  Ozzies, for reasons that escape me, sometimes wear the little skull caps – tied on to prevent being ripped off by 2 meter waves, on a calm day, at Manly.

Perhaps we can agree that a good Rule of Thumb helps both the experienced and not-so-knowledgeable:  then we can look at clinical pathways or protocols as strings of such rules – some might say the “Cliff Notes” of emergency medicine.

I could write a “clinical pathway” for ankle sprains:

If the injury was sustained with even the vaguest suspicion of syncope or seizure, perform a thorough cardiac and neurologic history and physical.  If not, perform a careful exam to identify the injured ligaments, neurovascular status, and degree of tenderness and swelling, then apply the Ottawa ankle room or clinical gestalt.  Don’t waste time on a detailed neuro/cardiac/pulmonary exam that is highly unlikely to yield useable information.

If an x-ray is indicated, peruse it carefully.  If it is normal, stress the ankle.  If it is not normal, do something appropriate.

You get the idea.

BTW, I’m often distressed at how often “clinical” pathways often ignore the clinical: the history and physical and assume that only the ancillary data will aid with diagnosis:   ACS guidelines that pay little attention to details of history (“Typical”, or twice in 24 hours seems to be as close as we get), but great attention to EKG, troponin, provocative or imaging tests.  But, we might be distressed that the current arc of emergency medicine seems to ignore, more and more, the history and the exam in favor of specific and expensive testing.

But, overall the use of such protocols or pathways do have clearly defined advantages:

•  The inexperienced are provided with a quickly attainable degree of expertise – assuming that they have sufficient training background to get to the correct pathway and use it reasonably (certainly not a uniformly safe assumption).
• The experienced and well trained are provided with a tool that saves time and effort, and minimizes errors of omission and errors resulting from divided attention or impaired attention.
• The guideline provides a framework for efficient communication and transfer of responsibility from one service to another without having to reinvent the wheel (or the rule).

Seems like the pathway or protocol is a critical part of modern medicine.

Two articles appeared between the initial and final drafts of this blog:

I suspect many are aware of the ProCESS trial that demonstrated little or no outcome difference among 3 groups:  full-bird adherence to the original EGDT protocol, a second group of “EGDT light” – no mandatory central venous monitoring, and “usual care” – do what you want to treat sepsis.

Another article in last weeks’s NEJM reported that in Ontario, Canada, the formal implementation of surgical checklists had no documentable significant change in surgical morbidity and mortality.

One interpretation of both of these articles, with studies performed well after extensive use of and dissemination of the basic tenets of aggressive care for sepsis and of a culture of safety around medical procedures, is that with time all of the stuff in the pathways and checklists becomes second nature, and we no longer need the documentation to keep us on the path to nirvana.  We’ve learned how to care for sepsis, and we’ve learned to always be sure to do the surgery on the correct leg, so we no longer need to follow a written pathway to get there.

Perhaps a comparison is an airliner cockpit:  the pilots go down a checklist before every takeoff and every landing.  But, if they happened to lose the checklist, they’d probably remember every (important) step and do it correctly even without the paper or electronic guide.  It would be tempting, after some number of takeoffs and landings, to eliminate the checklist.  Things would go just fine.  The problem is, that we humans may not have quite the durability of memory that a piece of paper or an iPad have:  after a few hundred more landings where the “landing gear down and locked” light always comes on, it becomes superfluous and silly to specifically look and note as to whether the light has come on (kinda like always looking at the optic fund for signs of papilledema before performing an LP – right, tell me that you always do that) and then you’re reliant upon the backup cues of a failure of the landing gear:  a very loud grinding noise and lots of sparks accompanying a rather rough landing.

It might not be wise to completely give up on surgical checklists, nor of an EGDT pathway just yet.

I’ll do some thinking and see if I can come up with any drawbacks to the use of clinical pathways and protocols and write about that later.  Drop me a comment if you can think of some – there must be some, maybe.

Ozzies, Sorry about the references to Tony, had to do it.

Later, mates.Next time:  The Land of Protocols