Journal: Curr Opin Anaesthesiol 21(3):259-262, 2008
Reprint: Department of Anaesthesiology, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium (M Van de Velde, MD, PhD)
Faculty Disclosure: Abstracted by L. Easley, who has nothing to disclose.
Spinal-induced hypotension is a common problem during cesarean delivery. This review focused on the usefulness and efficacy of low-dose spinal anesthesia to prevent maternal hypotension while maintaining good anesthetic conditions. Hypotension can cause maternal discomfort and impaired utero-placental perfusion, resulting in fetal academia. Various strategies have been described to prevent hypoten¬sion. A recent meta-analysis showed that although interventions such as colloids, ephedrine, phenyl¬ephrine or lower leg compression can reduce the incidence of hypotension, none has been shown to eliminate the need to treat maternal hypotension during spinal anesthesia for cesarean section.
Prophylactic management has been associated with side-effects. From various trials evaluating the effects of low-dose spinal anesthesia, it is clear that hypo¬tension occurs less frequently, is less severe and requires less pharmacological treatment when lower spinal doses are administered intrathecally as com¬pared with higher, more generally accepted doses. Many anesthetists would worry that lowering the spinal dose would reduce the quality of anesthesia and increase the incidence of pain during cesarean delivery. From prospective trials, it is clear that lowering the spinal dose improves maternal hemo¬dynamic stability. Doses of intrathecal bupivacaine between 5 mg and 7 mg are sufficient to provide effective anesthesia. Complete motor block is seldom achieved, and adequate anesthesia is limited in time. As a result, an epidural back-up catheter is a must.
From the authors' clinical experience, a bupivacaine dose between 5.5 mg and 6.5 mg combined with opioids provides reliable anesthesia from start of the spinal injection for 60-70 min. If the uterus is not closed after 45 min, an epidural top-up is given to prevent breakthrough pain. |
