Factors predicting difficulty in insertion of real-time-three-dimensional transesophageal echocardiography probe in adult patients undergoing cardiac surgery.

Background: Transesophageal echocardiography (TEE) probe insertion may be associated with many complications. Demographic factors and airway conditions such as high Mallampati scores (MMC) and Cormack-Lehane grades (MCLG) are likely to have an impact on its ease of insertion. The primary aim of this study was to identify the predictive factors for difficult real-time-three-dimensional TEE probe insertion.

Methods: A total of 153 adult patients undergoing cardiac surgery were prospectively evaluated. The upper airway manipulations required for TEE probe placement were jaw thrust, reverse Sellick's maneuver, and laryngoscopy. All the patients who required airway manipulations were grouped under difficult TEE probe placement group. We evaluated the patients' predictive factors such as demographic characteristics and factors related to difficult intubation.

Results: Out of 153 patients, 123 were males and 30 were females. Overall, 27.5% (n = 42) patients had difficulty in probe placement. About 31.7% (n = 39) males had difficulty in TEE probe placement against 13% (n = 4) females (P-value 0.045). Difficulty in TEE probe placement was found in 72.7% (n = 16) of obese patients (body mass index [BMI] > 30), compared to 18.6% (n = 17) in the patients with BMI less than 25 (P-value < 0.001). Probe insertion was significantly more difficult in the presence of MMC III and IV (50%, n = 18) compared to class I (19.2%, n = 10) (P-value 0.001) and MCLG III (73.3%, n = 22) compared to grade I (11.1%, n = 7) (P-value 0.001).

Conclusion: Male gender, obesity, higher grades of MMC and MCLG were found to be the risk factors for difficult TEE probe placement in anesthetized patients.