[Doppler effect and the Swan-Ganz catheter. Advantage in diagnosis and treatment of gaseous embolism by neurosurgical procedure (author's transl)].

During the neurosurgical procedure in the sitting position a prospective study was performed with a Swan-Ganz catheter on 99 subjects. Gaseous embolism occured in 11 subjects (11%). The frequency increased twofold in the surgery of pontocerebellar angle tumors. Haemodynamic study of 10 gaseous embolisms showed a rise in pulmonary arterial pressure (15.3 +/- 5.2 to 32.4 +/- 32.4 +/- 7.7 mm Hg; p < 0.005) with a rise in pulmonary resistances (22 +/- 1.2 to 9.0 +/- 3.1 units; p < 0.005) and in right ventricular systolic work index (7.8 +/- 1.3 to 14.4 +/- 6.3 gm/m2; p < 0.02). The fall in mean arterial blood pressure was inconstant and moderate (89 +/- 19 to 78 +/- 23 mm Hg; p < 0.05) as was the fall in cardiac output (5.6 +/- 0.9 to 5.0 +/- 0.8 l/min; p < 0.01). Increasing FIO2 hid hypoxemia but, in five subjects, the intrapulmonary shunt rose from 7 to 31%. The therapeutic aspects are reviewed.