We investigated the effects of
pancuronium bromide pretreatment on cerebral blood flow (CBF) during
bicuculline-induced
seizures in anesthetized piglets. Arterial blood pressure,
gases, pH, cerebral electrocortical activity, and CBF (radioactive
microsphere) were monitored at baseline, 10 min after administration of
pancuronium (0.3 mg/kg i.v.; n = 9) or vehicle (
normal saline; n = 8), and again at 5, 15, and 60 min after
bicuculline (3 mg/kg i.v.). No change in CBF from baseline was observed
at 10 min after either saline or
pancuronium treatment, before induction of
seizures. In the saline group, CBF was 36 +/- 3 mL.min-1.100 g-1 before
bicuculline and increased to 166 +/- 24 and 205 +/- 35 mL.min-1.100 g-1 at 5 and 15 min, respectively, after
bicuculline, returning toward baseline by 60 min. In the
pancuronium group at 5 min after
bicuculline, CBF increased from 45 +/- 7 to 169 +/- 26 mL.min-1.100 g-1, but fell to 88 +/- 17 mL.min-1.100 g-1 at 15 min in contrast to saline-treated piglets. Also, at 15 min of
seizures, differences between groups were observed in arterial blood pressure,
gases, and pH. Although these variables were in the normal range with
pancuronium treatment, the saline-treated animals had increased arterial blood pressure (81 +/- 6 mm Hg) and PCO2 (6 +/- 0.4 kPa) and decreased PO2 (7 +/- 0.5 kPa) and pH (6.91 +/- 0.06). Electrocortical activity was abnormal during
seizures in both groups. At 60 min, reversal to normal activity was observed in six of nine
pancuronium-treated animals versus two of eight saline-treated animals. These data suggest that
pancuronium limits cerebral
hyperemia during prolonged
seizures by attenuating increases in blood pressure as a result of elimination of skeletal muscle activity. This leads to minimal alteration of arterial PCO2, PO2, and pH during
seizures.