The Effect of Intraoperative Transesophageal Echocardiography Probe Placement on the Endotracheal Tube Cuff Pressure in Adult Patients Undergoing On-Pump Cardiac Surgery

Abstract

Objectives: The study was directed toward documentation of the effect of transesophageal echocardiography (TEE) probe insertion on the endotracheal tube cuff pressure (CP) in adult patients undergoing on-pump coronary bypass surgery. The primary objective of this study was to assess whether CP reaches supranormal pressures during the different stages of intraoperative TEE examination. The secondary objective was to observe the effect of TEE probe placement on the ventilation parameters.

Design: A prospective observational study.

Setting: At a tertiary care cardiac center.

Participants: Thirty-four cardiac surgical patients older than 18 years of age who required intraoperative TEE examination.

Interventions: TEE probe insertion.

Measurements and main results: Following the induction of general anesthesia and tracheal intubation, a TEE probe was introduced. The endotracheal tube CP was recorded at 5 time zones: Before TEE probe insertion, during the insertion of the probe, during probe manipulation, probe in the transgastric position, and during removal of the probe. A nonparametric test was used for comparing intracuff pressure between pairs of time zones. There was a statistically significant difference in CP values between the baseline and those during different time zones (chi-square test = 134.77, degrees of freedom = 4, p = 0.001). There was a statistically significant difference in the peak pressure between different time points compared to baseline (p = 0.0001).

Conclusions: TEE probe placement in patients with tracheal intubation may be associated with a significant increase in CP well above the baseline pressure. With the possibility of the mean arterial pressures during cardiopulmonary bypass being substantially lower than expected, the findings of the current study raised the concern of predisposing the tracheal mucosa to hypoperfusion, with subsequent temporary or permanent tracheal damage. Hence, at least a baseline estimation of the endotracheal tube CP at the time of tracheal intubation, with the help of a pressure gauge in the operating room, may be considered as a safe practice.

Keywords: adult cardiac; cuff pressure; intubation, intratracheal; observational; transesophageal echocardiography.