A recognition primed decision model approach to the BMP problem

To restate the problem: The basic metabolic panel is very valuable. Too many students, residents and physicians seem to have an incomplete understanding of the information that the BMP can provide. This recent patient may make my point. 80-year-old patient admitted for hematemesis. Patient required several transfusions and volume resuscitation. No history of significant heart disease or lung disease. The patient spent 4 days in the ICU and then is transferred to our team early Monday morning. The intern briefly sees the patient and says she is stable – but does mention that she requires 3 liters nasal oxygen (no prior need for oxygen).  That day’s BMP gave us a big clue. On admission: 142 101 45 180 4.2 25 1.3     Monday morning   142 112 5 93 3.4 17 0.8       The task for you is to explain the bicarbonate drop from 25 to 17.  The albumin is normal – this patient does not have an increased anion gap.  What caused the bicarbonate drop? My explanation: In the RPDM (proposed by Gary Klein a major thought leader in naturalistic decision making), we start with system 1.  I have presented this problem to many internists and they have all made the same mistake – using system 1 and then not proceeding to test their assumption.  Thus, this problem leads to a classic diagnostic error in the majority of excellent physicians. Almost everyone immediately assumes that the patient has a normal gap acidosis.  When ...
Source: DB's Medical Rants - Category: Internal Medicine Authors: Tags: Acid-Base & Lytes Source Type: blogs