Oxygen metabolism in malignant hyperthermia susceptible skeletal muscle and the effects of static halothane exposure

Abstract

Maternal temperature increased (0.2±0.1 C;.p¼0.003) only after 4h epidural analgesia, with ERMF subsequently recorded in 7/38 women (18.4%). Bupivacaine did not alter OXPHOS in NRLP3-/-cells, or reverse~75% suppression of OXPHOS/ glycolysis on exposure to labour plasma (n¼5), suggesting bupivacaine is not injurious to mitochondria/pro-inflammatory. Caspase-1 activity was measurable in 14% fewer MNF cells (95%CI:8-20); n¼9) obtained from labouring women after 4h incubation with bupivacaine, which also increased intracellular IL-1ra by 25±9% in MNF (p<0.001; n¼8). Plasma IL-1ra increased by 38±5% over 4h in women without an epidural (n¼6), but not after epidural analgesia (n¼17). Bupivacaine reduces caspase-1 activity in circulating leukocytes and IL-1ra secretion. Reduced circulating levels of anti-pyrogenic IL1-ra, rather than pro-inflammatory inflammation, may promote ERMF