BioProject

Background: The aim of this study is to improve our understanding of the mechanisms underlying the function of corticosteriods in the limb muscles of ICU patients with acute quadriplegic myopathy (AQM) by using a unique porcine ICU model, i. More...

Background: The aim of this study is to improve our understanding of the mechanisms underlying the function of corticosteriods in the limb muscles of ICU patients with acute quadriplegic myopathy (AQM) by using a unique porcine ICU model, i.e., 5-day longitudinal experiments where animals are sedated, mechanically ventilated and exposed to factor triggering AQM that is hydrocortisone. Results: An increased expression of genes involved in kinase activity, cell cycle regulation and transcriptional regulation. A decreased expression in genes regulating heat shock proteins, cytoskeletal & sarcomeric and oxidative stress response were also apparent. Therefore, it appears that CS has an additive deleterious role in acute quadriplegic myopathywere also apparent. Conclusions: CS induced molecular mechanisms involving kinase activity and heat shock protein genes were forwarded as probable mechanisms underlying the decreased force generating capacity. Overall design: Eight female domestic piglets (Sus scrofa, average body weight 26.4 kg) were used in this study. Piglets were immobilized by anesthesia and mechanically ventilated via a tracheotomy for a period of five days. During this study period, the animals were sedated using isoflurane inhalation (Abbott Laboratories, Chicago, Il, USA, 0.8 - 1.3% end-tidal concentration) supplemented by intravenous bolus doses of morphine and ketamine as needed. Core body temperature (blood) was maintained in the range of 38.5 - 40°C by a servo controlled heating pad. The animals received intravenous crystalloid fluid (Ringeracetat) to maintain stable blood pressure and urinary output and a glucose infusion (Rehydrex, Fresenius Kabi, Stockholm, Sweden, 25 mg glucose /mL) in the range of 0.5 - 1.5 mg/kg/minute to decrease the effects of catabolism. Each animal received prophylactic streptomycin 750 mg/d and bensylpenicillin 600 mg/d (Streptocillin Vet, Boeringer-Ingelheim, Hellerup, Denmark). Arterial blood gas analysis as well as electrolytes and blood glucose levels were monitored regularly and kept in the normal range throughout the study period. A neuromuscular blocking agent (NMBA) was administered as a continuous infusion of pancuronium bromide 0.1mg/kg/h (Pavolun; Organon, Boxtel, The Netherlands) for 5days while a corticosteroid (CS) was given as bolus doses of hydrocortisone. Keywords: Treatment, immobilization, muscle function. Less...