Detection of malintubation via defibrillator pads.
OBJECTIVE
Endotracheal intubation is the preferred method to ensure proper artificial ventilation. Early detection of esophageal intubation is important for an individual patient's outcome. The aim of the study was to see if impedance measurements can be used to detect esophageal intubation, using the impedance measurement system of an experimental defibrillator.


METHODS
Patients who died at the emergency department of a tertiary care hospital were eligible to be studied. After death was declared, patients were ventilated with a predefined tidal volume alternately via the conventional tracheal tube and via an additionally tube placed into the esophagus. The lowest and respectively highest median impedance amplitude for the first three ventilations was used as cut-off to calculate predictive values.


RESULTS
We enrolled 10 patients (mean age 65 years (S.D. 14), 7 male) of whom 9 underwent CPR prior to death, 30% of the patients had a BMI>30. Severe lung-edema was present in 2 cases. The lowest tracheal impedance value was 0.736 ohms and the highest esophageal was 0.496 ohms. A ROC curve for this individualised approach gave an area under the curve of 1 (95% CI 0.001, 0.249).


CONCLUSIONS
There is a large and significant reduction in transthoracic impedance when the tube is malpositioned in the esophagus. It may therefore be feasible to detect malintubation via thoracic impedance changes as an aid to improve the survival of critical ill patients. Further investigations on a larger population are needed.
Köhler
Klemens W
KW
Department of Emergency Medicine, Medical University of Vienna, General Hospital of Vienna, Austria.
Losert
Heidrun
H
Myklebust
Helge
H
Nysaether
Jon
J
Fleischhackl
Roman
R
Sodeck
Gottfried
G
Sterz
Fritz
F
Herkner
Harald
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007049:Iatrogenic Disease; D007442:Intubation, Intratracheal / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies