Postprocedural clinical and laboratory evaluation of sheep submitted to different intrabdominal pressures during laparoscopy

Abstract

The sheep experimental model is increasingly being used in laparoscopy, and there is a need to ensure animal welfare during and after the procedures. Therefore, the present study aims to evaluate postprocedural clinical and laboratory variables of sheep submitted to different intrabdominal pressures during laparoscopy. Ten female nonpregnant healthy adult Santa Ines ewes (48.8 ± 5.6 kg) were randomly submitted to a crossover study using different intrabdominal pressures (IAPs): 0 mmHg (G1), 10 mmHg (G2), 12 mmHg (G3), and 15 mmHg (G4). They were anesthetized and mechanically ventilated (VT =15 ml.kg−1) with positive end-expiratory pressure (3 cmH2O) and FiO2 = 1.0. At the same time, pneumoperitoneum was induced and maintained by Hasson's trocar cannula attached to an insufflator with no invasive visceral intervention. Physical examination and malondialdehyde levels were gathered immediately before (T0), 24 h (T1), 72 h (T2), 7 days (T3), and 14 days (T4) after the procedure. Hematology variables and fibrinogen were gathered at T0, T2, and T3, while serum biochemistry at T0 and T2. In the group with 15 mmHg of IAP, fibrinogen concentration was above normal level suggesting a late inflammatory response that persisted for up to 7 days (610 ± 335 mg/dL); Malondialdehyde concentration persisted in ascending levels for up to 14 days (from 257.2 ± 136.5–369.7 ± 201.4 nM/g Hb), and the opposite was observed in other groups. White blood cell (WBC), neutrophils, lymphocytes, and N:L ratios increased above normal levels in 72 h post-procedure and returned to normal within 7 days, except in the group of 15 mmHg of IAP which the highest value was reached 7 days post-procedure. Alterations in clinical parameters were mild and within normal values for the specie and breed in all groups. Biochemical analysis for all parameters was within the normal range in all groups. Still, monitoring aspartate aminotransferase (AST) up to 7 days after laparoscopic procedures is advisable due to its 72 h increase. Although no significant clinical and hematological alterations were observed, biochemical alterations and oxidative stress were greater up to 14 days after the procedure in the group with 15 mmHg IAP.