Effect of pneumoperitoneum on gastrointestinal motility, pain behaviors, and stress biomarkers in guinea pigs (Cavia porcellus)

OBJECTIVETo compare stress markers, gastrointestinal motility, and behavioral indicators of pain between guinea pigs undergoing pneumoperitoneum with carbon dioxide (CO2) and control guinea pigs. ANIMALSFourteen 4- to 5-month-old intact female Hartley guinea pigs. PROCEDURESGuinea pigs were randomized to receive insufflation or serve as controls (anesthesia and abdominal catheter placement without insufflation), with 7 animals/group. Insufflated animals underwent 6 mm Hg of CO2 pneumoperitoneum for 30 minutes. Afterward, results for vital signs, blood glucose, fecal cortisol, appetite, fecal output, and behaviors (via video recording) were compared between the 2 groups. RESULTSThere was no difference between groups and over time for body temperature, heart rate, fecal output in grams, pellets consumed, blood glucose, and fecal cortisol. Guinea pigs that underwent insufflation had significantly more fecal pellets at 36 hours after the procedure. Several behaviors were expressed similarly between groups and over time, such as body turns, incomplete movement, rearing, lying down, drinking, and hiding. Coprophagy occurred less often in the insufflated versus noninsufflated group at 12 h postprocedure but was similar between groups at other time points. At 60 hours after the procedure, insufflated animals spent less time squinting compared to noninsufflated animals. Other behaviors were differentially expressed over time but not between treatments. CLINICAL RELEVANCEOverall, there were no major differences in appetite, stress markers, and behaviors between insufflated and control guinea pigs. CO2 insufflation did not appear to cause undue pain or stress in guinea pigs and may be a reasonable technique to use during laparoscopy.