Haemodynamic effects of three doses of dihydroergotamine during spinal anaesthesia.

We performed a randomized study comparing the haemodynamic effects of three doses of the vasopressor dihydroergotamine (DHE) (5, 10 and 15 microg x kg(-1)) in 30 ASA 1 and 2 patients, aged 53-87 yr, undergoing spinal anaesthesia. Non-invasive systolic arterial pressure (SAP), heart rate and central venous pressure (CVP) were recorded continuously for 25 min. Intravenous fluids were withheld during this period. All three doses of DHE reversed the lowering effects of spinal anaesthesia on SAP and CVP (P<0.0001), and these effects were smooth in onset and sustained. Whereas the lowest (5 microg x kg(-1)) dose restored SAP and CVP to near prespinal values, the higher (10 and 15 microg x kg(-1)) doses resulted in above-baseline increases in SAP of 7% and in CVP of 2.7 cm H2O (P<0.05). The haemodynamic profile of DHE makes it a useful agent for managing hypotension during spinal anaesthesia. A dose of 5-10 microg x kg(-1) is recommended.