Comparison of two techniques of administering the Valsalva manoeuvre in patients under general anaesthesia: A randomised controlled study

Surgeons often request a Valsalva manoeuvre (VM) at the end of surgery (head-neck surgery, craniotomy) to check haemostasis and to unmask covert venous bleeders. We aimed to compare an anaesthesia machine-generated objective technique for delivering VM under pressure-control (PC) mode with the traditional subjective technique of delivering VM in manual mode.