Accuracy of the minimal leak test for endotracheal cuff pressure monitoring.

OBJECTIVES

To determine the accuracy of the minimum leak test as a surrogate for target endotracheal cuff pressure of 20-30 cm H2 O in intubated patients.

METHODS

Cuff pressures were measured at the University of Miami Hospital using the minimum leak test on every intubated patient once per shift, then cuff pressure was reevaluated using handheld numerical manometers and recorded pressures above or below the target range, readjusting the pressure as needed. This assessment was repeated throughout each patient's intubation for up to 6 days. The readjustment rate of the test and the probability of a patient needing at least one adjustment were determined.

RESULTS

One hundred twenty-two patients were evaluated. Median age was 67 years (range 29-95), 52% were male, 48% were female. Patients were followed for an average of 4.7 days. Seven hundred twenty-two minimum leak tests were performed. Of these, 170 required readjustment into the target range (24% readjustment rate). Of the tests outside target range, 66% of cuffs were overinflated and 34% were underinflated. Fifty-five percent of patients required at least one adjustment.

CONCLUSION

Despite ubiquitous use of the minimum leak test for endotracheal cuff pressure adjustment, the test has an unacceptably high error rate resulting in cuff pressures above or below the target range. Most patients will require at least one adjustment throughout an intubation, putting them at risk for tracheal injury, stenosis, or leak and aspiration. The minimum leak test is not sufficiently accurate for endotracheal cuff pressure monitoring. Formal manometry is superior and should be used to optimize patient outcomes.

LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1646-1650, 2020.