The ability of the patient to remain alive, and even stable, in spite of medical mismanagement, does not mean that the endotracheal tube has been placed endotracheally.
We have an infinite capacity for self-deception. This case is just one example of what is probably the most common mistake in medicine.
We report here a case of uneventful prolonged misdiagnosis of esophageal intubation with particular emphasis on failure to properly assess the important clinical diagnostic signs and radiologic features necessary for diagnosis.
Failure to properly assess, apparently because of a bias of unjustified faith in one’s own competence. This is not to pick on these doctors involved, since I have already pointed out that this is probably the most common mistake in medicine.
Proper tube placement was determined by auscultation of breath sounds bilaterally and apparent chest movements during positive pressure ventilation using an Ambu-bag.
This is a horribly inadequate method of confirmation of tube placement.
Addition of a color change carbon dioxide detector is not much better, but may have resulted in identification of the esophageal tube placement much earlier
She was also examined by several other resident physicians and a pulmonary fellow who were familiar with proper endotracheal intubation.
We are afraid to point out the errors of our colleagues, or those with higher education.
Sometimes those with the most education are best able to convince themselves that their unjustified biases are actually valid, in spite of the evidence to the contrary.
Initial arterial blood gases revealed pH 7.20, PaCO2 65 torr, and PaO2 51 torr.
Normal values –
pH 7.35 – 7.45.
PaCO2 35 – 45 mm Hg (torr).
PaO2 75 – 100 mm Hg.
For perspective, 60 mm Hg is roughly equal to an SpO2 of 90% in a normal healthy patient with a good pH, so a PaO2 of 51 (SpO2 of maybe 70% to 80%) should result in an aggressive search for the cause.
That did not happen.
This patient remained stable.
A stable patient can make it easier to rationalize unexpected assessment findings, that do not confirm our biases.
Repeat auscultation of the lungs by the same group of physicians revealed audible air entry over the chest bilaterally.
This is just another example of the lack of importance of listening to lung sounds for assessment of tube placement.
That is one of the reasons I teach people to listen first listen to the stomach.
The patient’s BP, HR, and clinical condition remained stable and the neurological evaluation for the etiology coma was continued.
Stable, but not good, and not suggesting proper tube placement.
Because of the hypercapnia, the rate of the mechanical ventilator was increased to 20 breath/min.
Similarly, just turning the oxygen up does not fix the underlying problem of a low oxygen saturation.
Several minutes later, gastric contents were observed inside the endotracheal tube and tubing of the mechanical ventilator. This occurred approximately 80 min from the start of intubation.
The medical term for this is Oops.
Nothing says esophageal as clearly as vomit in the endotracheal tube.
Retrospective comparison with the previous films revealed prior esophageal intubation since the endotracheal tube was positioned outside the tracheal walls.
The caption contest winner for this X-ray might be – You thought the tube was where?
Repeat ABG (Arterial Blood Gas) – pH 7.47, PaCO2 28 torr, and PaO2 270 torr, which indicates a slight overcorrection of the previous problems, but nothing bad.
Complications of endotracheal intubation include inadvertent endobronchial and esophageal intubation. 
This is nothing new.
Esophageal intubation is usually suspected during subsequent positive pressure ventilation when there is failure to hear any air enter the lungs, and failure to observe chest wall expansion. This is further supported when auscultation over the the abdomen reveals the presence of air entry into the stomach.
There are two extremes of approach to assessment of the location of the endotracheal tube.
1. Confirmation – The search for evidence to support the bias that the tube is in – often supported by the chant of the incompetent –
I saw the tube go through the cords.
2. Disconfirmation – The position of the tube is uncertain and should be presumed to be in the wrong place with a continual search for evidence of misplacement.
None of the observers auscultated over the abdomen to determine air entry into the stomach, an important sign when present.
My experience is that most people in medicine tend to assume that we do not make mistakes and that searching for evidence that something went wrong is foolish and insulting.
As if we would not have patients if things did not go wrong frequently.
We worry too much about perceived insults and not enough about our patients.
Batra AK, & Cohn MA (1983). Uneventful prolonged misdiagnosis of esophageal intubation. Critical care medicine, 11 (9), 763-4 PMID: 6884056