Impact of different analgesic depths and abdominal trauma of different severities on stress and recovery of rats undergoing total intravenous anesthesia

Abstract

A number of animal models have been developed to examine the pathophysiological consequences of surgical procedures, but anesthetic methods, monitoring, and management measures in these models are very different from those used in humans. This study was designed to create a rat model of abdominal surgery using anesthetic methods and perioperative treatment similar to those used in the clinic and to investigate the effects of different injury severities and depths of anesthesia and analgesia on surgical stress and postoperative recovery. Abdominal skin/muscle incision was compared with exploratory laparotomy in rats under propofol intravenous anesthesia, accompanied by perioperative measures such as oxygen inhalation, fluid infusion, warmth, blood gas analysis, and infection prevention. Stress indices (mean arterial pressure, heart rate, blood glucose, and plasma corticosterone) were monitored during anesthesia and surgery, and recovery indicators (body weight, food consumption, and pain) were measured after surgery. In addition, animals undergoing laparotomy were subjected to low and high dosages of propofol and sufentanil, in order to examine the relationship between anesthetic and analgesic depth and stress on recovery. Exploratory laparotomy induced a greater stress response and caused slower postoperative recovery as measured than somatic injury. High-dose sufentanil downregulated plasma corticosterone and improved postoperative recovery more effectively than high-dose propofol (P<0.05). Taken together, a rat model of abdominal surgery using anesthetic methods and perioperative treatment similar to those used in the clinic was successfully developed. It showed a positive correlation between severity of surgical trauma and stress response and postoperative recovery and a significant role of adequate analgesia in reducing surgical stress and improving postoperative recovery.

A rat model to investigate quality of recovery after abdominal surgery

“… 21 Also, our series of experiments confirm and extend existing knowledge by demonstrating that in animals, laparotomy induces measurable parameters of sickness behavior. 19 , 28 Laparotomized rats also showed abdominal mechanical allodynia as previously described by Charlet et al However, the duration of allodynia was shorter in our study. The difference in the duration of the allodynia could be explained by differences in the models such as the implantation of electrodes and a transmitter for heart rate monitoring in the study by Charlet.…”

Identification of Brain Regions Activated by Sevoflurane and Propofol and Regional Changes in Gene Expression

“…The procedure from holding the rats to releasing them was completed within 5 min. Rats in the propofol group were randomly allocated to three groups: propofol (intravenous 36 mg/kg/hr after a 10 mg/kg bolus dose: based on previous studies [ 19 , 36 ], Pfizer Japan, Tokyo, Japan), intralipos (10% lipid, intravenous 36 mg/kg/hr after a 10 mg/kg bolus dose, Otsuka Pharmaceutical, Tokyo, Japan) and sham (plastic catheter placement only). Note that intralipos was used as one of the controls to adjust the intravenous caloric infusion because propofol is a lipid emulsion-based anesthetic [ 5 ].…”