Cardiac output changes during Caesarean section. Measurement by transcutaneous aortovelography

A non-invasive technique of measuring cardiac output changes is described and studies of its accuracy and reproducibility are reviewed. Cardiac output changes in 11 patients undergoing Caesarean section under general anaesthesia were measured with this technique. Increases in cardiac output after induction and commencement of surgery (mean 19%, p less than 0.05), and after delivery (mean 19%, p less than 0.05) were found.