The Gist: Knowledge translation is a problem in medicine and, at the individual level, unlearning likely contributes to the knowledge translation gap. It may also exist as part of the solution. Akin to yoga, unlearning requires flexibility, training or deliberate practice, and is enhanced by a community open to skepticism and growth.
- Note: These musings are not evidence based but are more of a cognitive framework to understand why we have such difficulty individually changing practice.
Flexibility - Unlearning requires cognitive flexibility. When we stretch our bodies, we reach a point where we feel a burn; our body telling us we are approaching our limit. We can push further safely, it just burns slightly more. Unlearning is essentially the same and is often accompanied by “the burn.” When we come across information counter to the way we practice, it stings. We may feel defensive. This is “the burn.” We experience discomfort when we stretch our thinking beyond this. This may be, in part, because we are emotionally tied to our knowledge. We work hard for what we know. We act quickly in emergency care and must have confidence in what we know, as emergent situations do not typically allow for debate or significant time to think.
- A fix: When one feels “the burn” when confronted with new information that runs counter to our practice, recognize that this is a warning sign that knowledge may be changing. Recognize that the sting comes from our ego, protecting what we know. This does not mean that one should change practice whenever we come across a piece of novel information. Rather, we should we aware that in order to practice evidence based, up to date medicine, we may feel discomfort. When our beliefs are challenged, instead of becoming defensive, we should thoughtfully consider the information.
- Early Exposure - The earlier we begin training, the more prepared we are. If one has an upcoming race, we may expect we will perform better if we begin preparing earlier rather than the week before the race. Similarly, when it comes to unlearning a habit or a way of thinking, the sooner we are exposed to the contrary argument, the more prepared we may be to unlearn. This may serve as a preconditioning so that we may react less strongly upon repeat exposure.
- Repeat Exposure - Practice is central to most athletic endeavors. The more repetitions we do, the stronger we become. The more we practice a yoga pose, the more likely we are to be successful, the more comfortable it will feel. Unlearning is easier when we are exposed to the target bit of knowledge more frequently. Spaced repetition exists as one of the most evidence-based means of learning and this probably applies to unlearning.
Unlearning in the Prehospital Arena: The WorkoutNeedle Decompression for Tension Pneumothorax (see this post or this podcast). The second intercostal space at the midclavicular line (2nd ICS MCL) has been taught as the ideal spot for needle decompression. This, however, is changing. New recommendations are to use a catheter at least 8cm in length if needle decompression is attempted at the 2nd ICS MCL or decompress at the fourth or fifth intercostal space at the anterior axillary line (4/5th ICS AAL).
The chest wall is thick at the 2nd ICS MCL [1,2]. Radiographic studies of chest wall thickness demonstrate increased thickness at the 2nd ICS MCL compared with the 4/5th ICS AAL (4.78 cm vs 3.42 cm). Even ATLS states that needle decompression in the 2nd ICS MCL will fail more than 50 percent of the time. This is an intervention undertaken in extreme circumstances in critically ill patients. A chance of failure of 1 in 2 is unacceptable.
The 2nd ICS MCL is difficult to identify [3,4]. The clavicle extends further than most people think. As a result, providers are less accurate in identifying the 2nd ICS MCL compared with the 4/5th ICS AAL.
The pulse check. If one were to survey cardiac arrest resuscitation across the United States, in and out of hospital, we would probably see that the majority of people pause every two minutes for a “pulse check” despite decreased emphasis on the pulse check by the AHA guidelines over the past 10 years. The guidelines recommend minimal interruptions for pulse check and detail the problematic sensitivity and specificity of pulse identification . After the initial pulse check prior to CPR, the guidelines don’t actually specify any time frame for repeat pulse checks. Yet, many of us do. Sure, we can pause for rhythm analysis; however, many systems and the European guidelines now recommend pulse assessment upon observation of an organized rhythm or increase in end tidal capnography .
Few people can determine the presence of pulselessness in 10 seconds. Dick et al of patients placed on cardiopulmonary bypass and providers blinded to whether or not the patient actually had a pulse. Only 2% of this cohort of experienced providers were able to identify a pulseless patient in 10 seconds . With increased emphasis on compression fraction, this may result in a delay in resumption of compressions.
The accuracy of the pulse identification by providers is suboptimal, noted to be 78% in one study . While an accuracy of 78% may seem high, this means that approximately one in four times we will be wrong. We may feel the reverberation of our own pulse and the truly pulseless patient may have an unnecessary and perhaps deleterious delay in chest compressions.
For more on this topic check out this post and/or this post.
Left Bundle Branch Block (LBBB) as a STEMI Equivalent (check out this post)- Prior to the 2013 iteration of the AHA guidelines for ST-elevation myocardial infarction (STEMI), new or presumed new LBBB existed as a “STEMI equivalent.” This often activated the cath lab and STEMI teams. In 2013, the AHA removed this from the guidelines yet these patients are often referred to the emergency department for “rule out MI.”
Further, STEMI may often be diagnosed on ECG, using the Sgarbossa or modified Sgarbossa criteria (link) .
Backboards - fortunately protocols in many states and systems have dispensed with long backboards. Long thought to be protective, despite known harms, the American College of Emergency Physicians released a guideline in 2016 explicitly stating that long backboards should not be used as a therapeutic or precautionary measure. They cause harm and don’t help. 
Oxygen in Acute Coronary Syndromes - Aspirin, oxygen, and nitroglycerin have long been the initial interventions for patients with suspected ACS. Recent studies have found no clear benefit for oxygen in patients with normal oxygen saturations. Further, one study found oxygen was associated with markers of larger myocardial infarctions (although this is not a patient-oriented outcome) . The AHA recommends oxygen is appropriate for patients who are hypoxemic (oxygen saturation < 90%) .
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