Angiotensin in cardiac surgery: efficacy in patients on angiotensin converting enzyme inhibitors.
BACKGROUND
Patients presenting for cardiac surgery are often treated with angiotensin converting enzyme inhibitors (ACEIs), either for heart failure or hypertension. Control of systemic vascular resistance (SVR) during surgery can be difficult in such patients. Angiotensin II has been available as an unlicensed vasoconstrictor, but there is concern about renal damage and its use.


OBJECTIVE
This study compared a standard vasoconstrictor with angiotensin II and examined the effect on renal function after cardiac surgery.


METHODS
Twenty consecutive, consenting patients scheduled for cardiac surgery that had been taking ACEIs for at least 6 months, were randomly assigned to receive either phenylephrine or angiotensin II for the control of SVR during and for 24 h after cardiac surgery. A pulmonary artery catheter was used to guide therapy. Creatinine clearance was measured before, 24 and 48 h after surgery.


RESULTS
Low SVR and blood pressure requiring intervention was seen in all patients, particularly during cardiopulmonary bypass. One patient in the control group failed to respond to P, but responded normally to angiotensin II. Neither drug caused renal impairment.


CONCLUSIONS
Angiotensin II is a safe alternative to phenylephrine in patients on ACEIs and should be considered in patients who fail to respond to conventional vasoconstrictors.
Bennett
S R
SR
Department of Anaesthesia, Castle Hill Hospital, Cottingham, East Yorkshire HU16 5JQ, UK. sean@kemproad.freeserve.co.uk
McKeown
J
J
Drew
P
P
Griffin
S
S
D000704:Analysis of Variance; D000804:Angiotensin II / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D006348:Cardiac Surgical Procedures; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D006973:Hypertension / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010656:Phenylephrine / Q000627:therapeutic use*; D014655:Vascular Resistance / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
D000806:Angiotensin-Converting Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D010656:Phenylephrine