Effect of transesophageal echocardiography probe on tracheal perfusion pressure and ventilatory parameters in pediatric patients undergoing cardiac surgery using cardiopulmonary bypass: A prospective observational study.

Abstract

Background: Overinflation of cuffed endotracheal tubes and transesophageal echocardiography (TEE) probe causes increased intracuff pressure (CP) compromising tracheal perfusion pressure (TPP). Primary objective of the study was to assess CP, TPP on TEE probe insertion and examination during pediatric cardiac surgeries. Secondary objectives were to evaluate the effect of the probe on peak airway pressures (P_peak), mean airway pressures (P_mean) and to monitor CP, TPP on cardiopulmonary bypass (CPB).

Materials and methods: This prospective observational study included fifty patients, aged 1-5 years undergoing cardiac surgeries using CPB. Following induction, TEE probe was introduced. CP, TPP, P_peak, P_mean were measured before insertion of TEE probe (T₁), during probe insertion (T₂) and examination at mid-esophageal (T₃), transgastric level (T₄), and on removing probe (T₆). CP, TPP were monitored on CPB (T₅). Statistical analysis was done using paired t-test.

Results: CP, P_peak and P_mean increased significantly, while TPP decreased significantly from T₁ to T₂, T₃, T₄ (P < 0.001). CP, TPP decreased significantly at T₅ in comparison to T₆ (P < 0.001). In 48% of the patients CP increased above 30 cm H₂O at T₂.

Conclusion: TEE probe causes an increase in CP and decreases TPP. Constant monitoring and maintaining CP, TPP in optimum range is recommended.