Blood gas and hemodynamic effects of sedatives and analgesics when used as a supplement to local anesthesia in plastic surgery.

In 20 patients undergoing a rhinoplasty or rhytidectomy under local anesthesia combined with intravenous sedatives and hypnotics, fairly satisfactory operating conditions were obtained. This technique was associated with respiratory depression and hypoxia, however, with statistically significant elevations in the arterial carbon dioxide tensions, and depressions in the arterial oxygen tensions. We now advocate the routine use of supplement oxygen and periodic deep breathing during the operation, and in the immediate postoperative period. We will continue to advise the use of general anesthesia in patients with cardiopulmonary disease. The mental detachment and inability to articulate discomfort during the procedure are major disadvantages to the use of fentanyl and droperidol in these patients.

Positive end-expiratory pressure in weaning patients from controlled ventilation. A prospective randomised trial.

Twenty-five patients in acute respiratory failure were randomised to receive either 5 cm of positive end-expiratory pressure (P.E.E.P.) or no-P.E.E.P. while weaning from controlled ventilation. The use of P.E.E.P. resulted in a significant reduction in the increase in alveolar-arterial oxygen tension gradient (AaDO21) which occurred in the group of patients who were converted from controlled ventilation to spontaneous ventilation without P.E.E.P. Patients who weaned without P.E.E.P. had a mean increase in AaDO21 of 102+/-35 mm Hg S.E. while those who weaned with P.E.E.P. had a mean increase of only 10+/-22 mm Hg (P less than 0-03). The use of P.E.E.P. was also associated with a significant improvement in the vital capacity and the maximum inspiratory force. Patients who weaned with P.E.E.P. had an increase in vital capacity of 258+/-108 ml (P less than 0-05) and an increase in inspiratory force of -15+/-5 cm H2O (P less than 0-01), while patients who weaned without P.E.E.P. did not have significant changes in these measurements. The use of P.E.E.P. during weaning may be helpful in patients who fail to wean because of the development of hypoxaemia due to rapid alveolar collapse, since P.E.E.P. appears to minimise the increase in intrapulmonary right-to-left shunt which normally occurs during weaning from controlled ventilation.

A potentially serious complication with Swan-Ganz catheter placement by the percutaneous internal jugular route.

Percutaneous insertion of a Swan-Ganz catheter through the internal jugular vein is presumed to have resulted in lodgement of the catheter tip in the wall of the internal carotid artery.