Detection of gas embolism by transesophageal echocardiography during laparoscopic cholecystectomy

Using transesophageal echocardiography (TEE), 16 patients (ASA physical status I-III), undergoing laparoscopic cholecystectomy, were assessed for the occurrence of episodes of gas embolism and cardiovascular changes related to those emboli. The long-axis four-chamber view was monitored continuously, except for predetermined intervals where the transgastric short-axis view was obtained to derive the end-diastolic area (EDA), the end-systolic area (ESA), and the ejection fraction (EF). In one patient, we monitored the longitudinal view of the superior and the inferior vena cava. The monitoring of the patients also included: heart rate (HR), mean arterial pressure (MAP), arterial saturation by pulse oximetry (Spo2), end-tidal CO2 (ETCO2), minute ventilation (VE), and peak inspiratory pressure (PIP). Embolic events were defined as the appearance of gas bubbles in the right cardiac chambers. We observed gas embolism in 11/16 patients (five during peritoneal insufflation and six during gallbladder dissection). Using the longitudinal view of the superior and inferior vena cava (IVC), we found that these emboli were transmitted through the IVC. No episode of cardiorespiratory instability (decrease in MAP > or = 10 mm Hg, Spo2 < 90%) was observed. There was no significant difference in cardiorespiratory variables between patients who presented gas embolism (n = 11) and patients who did not (n = 5) during the studied period. In this small group of patients, we conclude that gas embolism occurs commonly during laparoscopic cholecystectomy but that these gas emboli cause minimal cardiorespiratory instability.