Gastric Myoelectric and Motor Activity in Dogs After Isoflurane Anesthesia

Abstract

To characterize the effects of isoflurane on gastric motility, gastric electrical and contractile activities were assessed in six healthy adult dogs before and after recovery from anesthesia. Baseline recordings (fasting and fed state) were obtained in unanesthestized dogs 8 days after implantation of serosal electrodes and strain-gauge force transducers. After an overnight fast, dogs were anesthetized with 1.3 minimum alveolar concentration (MAC) isoflurane for 4.5 hours (approximately 6 MAC hours). No other anesthetic or sedative drugs were administered. During anesthesia, ventilation was mechanically controlled to maintain arterial carbon dioxide tension at 36 +/- 4 mm Hg. Gastric electrical and contractile activities (fasting and fed state) were recorded again 18 hours after recovery from isoflurane anesthesia. Recordings were analyzed to determine gastric slow-wave frequency, presence of slow-wave dysrhythmias, slow-wave propagation velocity, coupling of contractions to slow waves, a motility index based on relative contractile amplitudes, and onset and duration of contractions after a standardized meal. The only variable that was significantly decreased 18 hours after 6 MAC hours of isoflurane anesthesia was the gastric motility index during fasting-state phase III. This decrease was not apparent in the fed-state test periods. Our results suggest that, with the exception of gastric motility index during fasting-state phase III, variables for gastric electrical and contractile activities in dogs are unaffected by isoflurane 18 hours after anesthesia.

Cerebral 6-[18F]fluoro-L-DOPA (FDOPA) metabolism in pig studied by positron emission tomography

“…In preliminary trials, carbidopa was administered via a gastric tube as tablets 60-90 min before the FDOPA infusion. However, the cerebral uptake of tracer was extremely variable in these animals, possibly due to inhibitory effects of anaesthesia on gastric motility and pH in pigs (Hall et al, 1995;Stødkilde-Jørgensen et al, 1985) resulting in variable carbidopa absorption. Thereafter, carbidopa was dissolved in 30 ml saline by slow heating, which was then cooled and administered as a slow (2-min) intravenous infusion ending 30 min before FDOPA injection (Chan et al, 1995).…”

Gastrointestinal Tracking and Gastric Emptying of Coated Capsules in Rats with or without Sedation Using CT imaging

“…When the effect of several anaesthetic agents on rat duodenum motility was investigated, all of the anaesthetic agents studied disrupted GI transit [15]. In dogs, a significant decrease in gastric myoelectric and motor activity was reported for 6 h following anaesthesia with isoflurane, and in the gastric motility index for 18 h post-anaesthesia [16]. In rats, even a brief exposure to isoflurane anaesthesia decreased GI motility which did not return to normal until 2 h later [17].…”

The effect of fasting on gastrointestinal motility in healthy dogs as assessed by sonography

“…Previous studies have used various invasive techniques to evaluate changes in GI motility with fasting in dogs. These procedures include serosal electrodes, strain‐gauge force transducers, and wireless motility capsule devices . Serosal electrodes and strain‐gauge force transducers require surgical implantation of electrodes.…”