[Prevention of arterial hypotension during spinal anesthesia using intramuscular ephedrine in older people]

To assess the efficacy of intramuscular ephedrine for prevention of hypotension following subarachnoid block (SB) in the elderly.

Prospective, randomized double blind study vs placebo.

Twenty patients, aged 60 years or more, of physical class ASA 2 or 3, scheduled for surgical fixation of fractured neck of femur under SB, allocated into two groups of ten each.

After oral premedication with hydroxyzine 50 mg, 90 min before surgery, and preloading with cristalloid solution 10 mL.kg-1, the subarachnoid space was punctured with the patient in lateral position using a 22 Gauge spinal needle at the L3-L4 or L4-L5 interspace. Patients were given 0.5% hyperbaric bupivacaine intrathecally, according to body weight. Patients in ephedrine group received intramuscular ephedrine 30 mg immediately after SB. Patients in placebo group received 1 mL of intramuscular saline immediately after SB. When blood pressure decreased below 100 mmHg repeated bolus of ephedrine 6 mg were given intravenously.

Patients in both groups experienced a significant decrease in systolic pressure after SB, the decrease being significantly greater in the placebo group.

Prophylactic intramuscular ephedrine is effective to prevent hypotension associated with SB in the elderly.