Effect of Pneumoperitoneum on Working Space, Cardiorespiratory Function, Gastrointestinal Motility, Stress, and Pain in the Guinea Pig (Cavia porcellus)
Laparoscopic surgery is associated with decreased postoperative pain compared to open surgery, but information regarding parameters for laparoscopy in guinea pigs is limited. The purpose of this thesis was 1) to evaluate the effects of intra-abdominal pressure (IAP) and body position on working space, 2) to evaluate cardiorespiratory effects of different IAPs on intubated and non-intubated guinea pigs undergoing CO2 insufflation, and 3) to compare post-procedure markers of stress, gastrointestinal motility, and pain in guinea pigs undergoing insufflation versus controls. In the first study, six female Hartley guinea pigs received different IAPs (4, 6, 8 mm Hg), and different recumbencies (dorsal, right lateral, left lateral) followed by abdominal CTs. There was a 7.3% increase in working space at 6 mm Hg and 19.8% increase at 8 mm Hg, when compared to 4 mm Hg. In the second study, the same six guinea pigs were used to evaluate cardiorespiratory effects of pneumoperitoneum at different IAPs (0, 4, 6 mm Hg), with and without intubation and ventilation. Non-intubated guinea pigs had significantly higher partial pressure of carbon dioxide (PCO2) and lower pH. 6 mm Hg resulted in significantly higher PCO2 compared to 0 and 4 mm Hg. In the final study, guinea pigs were randomly assigned to receive insufflation at an IAP of 6 mm Hg for 30 minutes (n=7) or anesthesia and abdominal catheter placement alone (n=7). Post-procedure, markers of gastrointestinal motility, stress, and pain were monitored for 2.5 days. There was no significant difference between groups for vitals, fecal output by weight, appetite, blood glucose, and fecal cortisol. A few variables were different between groups at single time points. Summed passive and active behaviors were not significantly different between groups. Although increases in IAP increase working space in guinea pigs, higher IAPs are associated with more severe adverse cardiorespiratory effects. Therefore, IAP should not exceed 4-6 mm Hg during laparoscopy. Intubation and ventilation are recommended for guinea pigs undergoing pneumoperitoneum. CO2 insufflation did not have major effects on post-procedure gastrointestinal motility, stress, or pain. Therefore, capnoperitoneum may be a reasonable technique to investigate further for laparoscopy in guinea pigs.
McCready JE, Gozzard H, Tisotti T, Beaufr??re HH. Effect of pneumoperitoneum on gastrointestinal motility, pain behaviors, and stress biomarkers in guinea pigs (Cavia porcellus). Am J Vet Res. 2022;83(8). doi: https://doi.org/10.2460/ajvr.22.01.0001.
McCready JE, Sanchez A, Tisotti T, Beaufr??re H. Cardiovascular and respiratory effects of capnoperitoneum in intubated and non-intubated guinea pigs (Cavia porcellus). In: ExoticsCon 2022 Proceedings. AAV, AEMV, and ARAV
McCready JE, Gozzard H, Tisotti T, Beaufrere H. Effect of pneumoperitoneum on gastrointestinal motility, pain behaviors, and stress biomarkers in guinea pigs (Cavia porcellus). In: ExoticsCon 2022 Proceedings. AAV, AEMV, and ARAV