Does the endotracheal tube cuff pressure increases with transesophageal probe insertion?

The cuff pressure (CP) of the endotracheal tube (ETT) exceeding 30 cm of H₂O results in reduced perfusion of lateral mucosa of trachea leading to complications. As the posterior tracheal wall is in contact with the esophagus, there is a possibility that the insertion of transesophageal echo (TEE) probe may compress the tracheal wall and increase CP.

This study was aimed to assess the impact of TEE probe insertion on CP in adults undergoing cardiac surgery.

Prospective observational study of 65 patients at tertiary care level hospital.

After balanced general anesthesia, patients were intubated with high volume low-pressure ET.TEE probe was then inserted with gentle jaw thrust. CP was measured by standard invasive pressure monitoring device at four points: T1 at baseline before TEE probe insertion; T2 maximum CP noted at TEE probe insertion; T3 at 5 min post TEE probe insertion; and T4 at post-TEE exam.

CP was compared between pairs of time points (T1 vs. T2; T1 vs. T3; and T1 vs. T4) using Mann-Whitney U test. Factors predicting CP >30 cm of H₂O at T4 were assessed by backward stepwise regression.

CP (mean ± S.D.) at T1, T2, T3, and T4 was 22 ± 3, 38 ± 10, 30 ± 6, and 30 ± 7, respectively. CP increased significantly from T1 to T2 (P < 0.001), T1 to T3 (P < 0.001), and T1 to T4 (P < 0.001). There were 26 patients (40%) with CP >30 cm of H₂O at end of TEE exam (T4). On multivariate analysis baseline, CP (T1) >20 cm of H₂O was significantly associated with CP >30 cm of H₂O at end of TEE exam with Odd's Ratio (OR) of 8.5 (1.76-41.06, P = 0.008).

To conclude, the CP increases significantly with TEE probe insertion in 40% of patients exceeding a safe limit of 30 cm of H₂O. The monitoring and optimization of CP is advisable.