Carboxyhaemoglobin formation and ECG changes during hysteroscopic surgery, transurethral prostatectomy and tonsillectomy using bipolar diathermy.

Diathermy is known to produce a mixture of waste products including carbon monoxide. During transcervical hysteroscopic surgery, carbon monoxide might enter the circulation leading to the formation of carboxyhaemoglobin. In 20 patients scheduled for transcervical hysteroscopic resection of myoma or endometrium, carboxyhaemoglobin was measured before and at the end of the surgical procedure, and compared with levels measured in 20 patients during transurethral prostatectomy, and in 20 patients during tonsillectomy. Haemodynamic data, including ST-segment changes, were recorded. Levels of carboxyhaemoglobin increased significantly during hysteroscopic surgery from median (IQR [range]) 1.0% (0.7-1.4 [0.5-4.9])% to 3.5% (2.0-6.1 [1.3-10.3]%, p < 0.001), compared with levels during prostatectomy or tonsillectomy. Significant ST-segment changes were observed in 50% of the patients during hysteroscopic surgery. Significant correlations were observed between the increase in carboxyhaemoglobin and the maximum ST-segment change (ρ = -0.707, p < 0.01), between the increase in carboxyhaemoglobin and intravasation (ρ = 0.625; p < 0.01), and between intravasation and the maximum ST-segment change (ρ = -0.761; p < 0.01). The increased carboxyhaemoglobin levels during hysteroscopic surgery appear to be related to the amount of intravasation and this could potentially be a contributing factor to the observed ST-segment changes.

How safe is the intravasation limit in hysteroscopic surgery?

BACKGROUND: Transcervical resection of myomas (TCR-M) is considered a safe hysteroscopic procedure if intravasation is limited. Complications may occur if gas formation during myoma resection leads to gaseous embolism. However, the incidence of emboli during transcervical myoma resection is unknown. Therefore in this study the occurrence of physiological changes that indicate the formation of emboli was retrospectively determined in patients undergoing hysteroscopic myoma resection. In addition, these changes were related to the amount of fluid intravasation. METHODS: The anesthesia records and operation files of 234 patients were screened for physiological changes that indicate embolism, as measured with standard intraoperative monitoring. These patients underwent surgery for intrauterine myomas with either a monopolar resectoscope with electrolyte-free distension fluid containing 3% sorbitol (limited to 1500-mL intravasation) or a bipolar resectoscope with normal saline solution (limited to 2500-mL intravasation). The patients were grouped according to the amount of fluid intravasation during the operation: Group 1: 500 mL or less, group 2: 500-1000 mL, group 3: 1000-1500 mL, and group 4: 1500-2500 mL. RESULTS: Physiological changes that could be attributed to gaseous embolism were observed in 33% to 43% of patients with 1000 to 2500 mL fluid intravasation during transcervical myoma resection. Nearly half of those patients had cardiovascular disturbances that indicated the formation of emboli. CONCLUSION: During transcervical resection of myomas, physiological changes that could be attributed to gaseous embolism frequently occurred. Therefore cardiovascular disturbances that indicate gaseous embolism during transcervical resection of myomas may occur despite the limitation of intravasation according to current view.

Paradoxical gas embolism by transpulmonary passage of venous emboli during hysteroscopic surgery: a case report and discussion.

After an episode of apparent venous gas embolism in a patient undergoing surgical hysteroscopy, transoesophageal echocardiography revealed air in the left but not in the right heart. Contrast echocardiography failed to demonstrate anatomical right-to-left shunts, making it likely that venous emboli overwhelmed the capacity of lungs to filter emboli, resulting in paradoxical embolization.