| JOURNAL HOME | CME HOME | THIS MONTH | PAST ISSUES | ETOC | COLLECTIONS |
| AUTHORS | REVIEWERS | EDITORIAL BOARD | FEEDBACK | RSS | HELP |
| ||||||||||||||
| ||||||||||||||
|
|
|
|
||||||||||||
|
||||||||||||||
Department of Anesthesiology, Sapporo Medical University, School of Medicine, Sapporo, Japan
Address correspondence and reprint requests to Kohki Nishikawa, MD, Department of Anesthesia, Otaru Hokusei Hospital, 8-18 Umegae-cho, Otaru, Hokkaido 047-0044, Japan. Address e-mail to nkouki{at}sapmed.ac.jp
In a double-blinded, placebo-controlled, randomized study, we evaluated the effect of prophylactic IM phenylephrine at doses of 1.5 and 3 mg on hyperbaric tetracaine spinal anesthesia-induced hypotension in 90 normotensive and hypertensive patients aged >65 yr undergoing surgery for hip fracture. Thirty normotensive patients received 1.5 or 3 mg of phenylephrine IM (N/P-1.5 and N/P-3.0 groups; n = 15 in each), whereas controls received saline (N/C group; n = 15), and 45 hypertensive patients were treated in a similar manner (H/P-1.5, H/P-3.0, and H/C groups; n = 15 in each). All groups had a peak sensory block height of T9, with a range of T8 to T10. The incidence of hypotension (>25% decrease in mean arterial blood pressure [MAP] from baseline) was significantly lower in the patients who received phenylephrine 1.5 or 3 mg than in the controls, both in the normotensive and hypertensive groups (P < 0.01). The N/P-3.0 and N/P-1.5 groups and the H/P-3.0 group had significantly lower percentage reductions in MAP (P < 0.05) and required significantly smaller doses of rescue IV ephedrine (P < 0.05) than did the N/C group or the H/C group. The H/P-1.5 group also required significantly less rescue IV ephedrine (P < 0.05), although it was not sufficient to significantly attenuate the percentage decrease in MAP compared with that in the H/C group. Bradycardia (heart rate <50 bpm) as an adverse effect after IM administration of phenylephrine was not observed in any of the groups. Hypertension (MAP >20% increase from baseline) after medication occurred in the N/P-3.0 and H/P-3.0 groups, but not in the N/P-1.5 and H/P-1.5 groups. We conclude that prophylactic IM injection of 1.5 mg of phenylephrine is a safe (defined as the inhibition of bradycardia and hypertension) and effective means of reducing the incidence of hypotension associated with spinal anesthesia in normotensive and hypertensive elderly patients.
IMPLICATIONS: We evaluated the efficacy and safety of small-dose IM phenylephrine for prophylaxis against spinal anesthesia-induced hypotension in normotensive and hypertensive elderly patients. Phenylephrine 1.5 mg IM was effective for reducing the incidence of hypotension and avoided adverse effects.
|
