EFFECT OF Paco ON CEREBRAL BLOOD FLOW DISTRIBUTION DURING HALOTHANE COMPARED WITH ISOFLURANE ANAESTHESIA IN THE RAT

Open Access
Publisher Website
Google Scholar
Abstract
In order to examine anaesthetic effects on the distribution of cerebral blood flow (CBF) during normo- and hypocapnia, male adult Sprague-Dawley rats were allocated randomly to four groups in a 2×2 factorial design, using PaC(,2 value and anaesthetic agent as between-group factors. Animals were anaesthetized with either 1.38%isoflurane (inspired) or 1.05% halothane (inspired) and the lungs ventilated mechanically at either normocapnia (PaC0) 5.1–5.6kPa) or hypocapnia (?aCOl 3.1–3.3 kPa) for 1 h. CBF was measured using 14C-iodoantipyrine autoradio-graphy. Local CBF in selected cortical and subcortical regions of interest and area - weighted mean global CBF were calculated. Data were compared by analysis of variance. Normocapnic (mean (SE)) CBF for halothane (n = 6) and isoflurane (n = 7) was 120 (8) ml/100 g min−1 (Paco, 5.6 (0.49) kPa) and 117 (9) mil 100 g min−1 (PaC0} 5.4 (0.5) kPa), respectively. Hypocapnic CBF for halothane (n = 6) and isoflurane (n = 6) was 82 (7) ml/100 g min−1 (PaC0} 3.3 (0.12) kPa) and 82 (6) ml/ 100 g min−1 (PaCOl3.2 (0.12) kPa), respectively. Hypocapnia reduced global CBF for both groups by 30% (P < 0.001), but there was no difference between anaesthetic agents (P >0.8). Hypocapnia decreased CBF in all local structures examined. Although subcortical structures had similar CBF at both normocapnia and hypocapnia, CBF in three cortical samples was greater (P −1 mm Hg). We conclude that halothane is a selective cortical vasodilator compared with isoflurane, but both agents have similar effects on global CBF and local and global CBF reactivity to changes in Paco

This publication has 0 references indexed in Scilit: