Cardiac output monitoring to guide fluid replacement in head and neck microvascular free flap surgery-what is current practice in the UK?

Appropriate fluid balance is an important factor in the survival of free flaps, and recently there has been a shift towards more conservative fluid regimens. Several surgical specialties have made extensive use of the relatively non-invasive method of measuring cardiac output (CO) to optimise fluid balance during and after surgery, which has resulted in a shorter hospital stay, but little has been published in head and neck surgery. To ascertain its use in the head and neck we sent a postal questionnaire to the anaesthetic departments of 40 major head and neck units identified from the 2010 database of the British Association of Oral and Maxillofacial Surgeons (BAOMS). Questions were asked about the number of free flaps done in the unit each year, the monitoring of central venous and arterial blood pressure (and inotrope protocols), optimal target variables, and whether CO was monitored (with type of device). Thirty-two units responded (80%). While 26 units (81%) routinely monitored central venous pressure (CVP), CO was monitored in only 3 units (9%). There was a wide range of responses in relation to optimal variables and use of inotropes. As with other specialties, it is likely that CO monitoring will become widely used in head and neck reconstructive surgery. Not only does it enhance fluid optimisation, but it may also reduce hospital stay and morbidity. Appropriate clinical studies are urgently needed to evaluate its use in our specialty.