Transesophageal Echocardiography-An Alternative Introduction Method

Background: Intraoperative transesophageal echocardiography (TEE) is now being done in many operations for monitoring and diagnostic procedure. It is generally contemplated as a relative safe and minimally invasive technique. However, unfavorable events may occur during TEE introduction or manipulation. Despite a high successful rate of TEE introduction was reported, special care may be taken in endotracheal intubated patients. Endotracheal tube may interfere with TEE probe introduction and requiring additional manipulations. Failure to introduce or advance the TEE probe in 0.18%-1.9% of anesthetized patients. In our study, we assessed whether the Portex laryngeal mask airway introducer (Portex introducer) can be an aid for TEE introduction in patients under endotracheal general anesthesia.Methods: 80 ASA II-III adult patients undergoing cardiac surgery were randomly allocated to TEE group, n=40 or TEE-I group, n=40 (TEE with the Portex introducer). Endotracheal intubation after the induction of fentanyl (3-5ug/kg), etomidate (0.4mg/kg) and rocuronium (0.6mg/kg) was given to facilitate tracheal intubation. TEE introduction was done with regular blind method in TEE group, but the Portex introducer was placed in the mouth prior TEE introduction in TEE-I group. TEE probe was advanced along the Portex introducer as an ”artificial hard palate” which intends to guide the TEE probe sliding through the pharyngeal turn and deflects the probe down into hypopharynx, and maintains a midline approach for the probe toward the esophageal inlet. The frequency of attempts of TEE introduction and introduction time were compared with each group. Complications caused by TEE were also recorded in two groups. Chi-square test with Yates' correction, Fisher's exact test and two tailed Student's t-test were used for statistics.Results: Not only the successful first-time introduction rates, TEE group 34(85)% vs TEE-I group 40 (100%, p＜0.05), were lower for the TEE group, but also the TEE introduction was assisted by laryngoscope in a patient of TEE group. There were 5 patients succeed in introduction after subsequent second attempt in TEE group. The introduction time was much significant faster in TEE-I group (9.2 ± 1.69 sec., p＜0.05) than in TEE group (12.2 ± 3.84 sec.). The frequency of postoperative sorethroat were 11 (28.2%) in TEE group and 6 (15%) in TEE-I group. A case of dysphagia and 3 cases had bloodtinged sputum after removal of probe in TEE group were noted. The patients experienced small tear over left upper lip were 2 in TEE group and 1 in TEE-I group.Conclusion: We showed that TEE introduction can be done more smoothly and promptly by the aid of the Portex introducer. It helps the TEE probe to overcome the major impediment of the pharyngeal turn during introduction and maintains a midline approach for the probe toward the esophageal inlet even the patients were endotracheal tube intubated.