Department of Pathology and Veterinary Clinic, Faculty of Veterinary Medicine, Fluminense Federal University, Niterói, RJ, Brazil.
Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Physiol Rep. 2022 Nov;10(21):e15506. doi: 10.14814/phy2.15506.
Increased intraabdominal pressure (IAP) during laparoscopy can reduce venous return, but changes in respiratory system mechanics and their effect in left cardiac function are not well documented. This study evaluated the effects of different IAPs on respiratory mechanics and cardiac function in 10 healthy nonpregnant adult Santa Ines ewes randomly submitted to a crossover study using different IAPs: 0 mm Hg (G1), 10 mm Hg (G2), 12 mmHg (G3), and 15 mmHg (G4). Animals were anesthetized and mechanically ventilated (V = 15 ml/kg; positive end-expiratory pressure = 3 cmH O; FiO = 1.0). Pneumoperitoneum was induced by Hasson's trocar cannula. Variables were measured at INITIAL (IAP, 0 mmHg) and FINAL time points for each IAP after 1 h. At FINAL, driving airway pressure (ΔP, ), and percentage fraction of dead space (Vd/Vt) were higher in G3 and G4 than G1 (p = 0.002, difference in means [MD] 4.60, 95% CI: 7.91-1.28, and p < 0.001, MD 5.4, 95% CI: 8.7-2.0; p = 0.016, MD -9.5, 95% CI: -17.9 to -1.2; and p = 0.027, MD -8.7, 95% CI: -17.1 to -0.4). The ejection fraction and fractional shortening were lower in G3 (p = 0.039, MD -11.38, 95% CI: -0.07--22.68; p = 0.015, MD -13.05, 95% CI: -1.74--24.36) and G4 (p = 0.039, MD -9.94, 95% CI: -0.07 to -19.80; p = 0.015, MD -11.43, 95%CI: -1.57 to -21.30, respectively) than G2. In G3, the maximum pulmonary flow velocity correlated negatively with ΔP, (r = -0.740; p = 0.018), and Vd/Vt correlated positively with ΔP, (r = 0.738, p = 0.046). At IAP of 12 and 15 mm Hg impaired respiratory system mechanics, reduced left cardiac function and no change in maximum pulmonary artery flow velocity were detected. Therefore, respiratory mechanics should be monitored as an interplay to reduce left cardiac function.
腹腔镜手术期间腹内压（IAP）升高会减少静脉回流，但呼吸系统力学的变化及其对左心功能的影响尚未得到很好的记录。本研究评估了不同 IAP 对 10 只健康非妊娠成年 Santa Ines 母羊呼吸力学和心脏功能的影响，这些母羊随机接受交叉研究，接受不同的 IAP：0 mmHg（G1）、10 mmHg（G2）、12 mmHg（G3）和 15 mmHg（G4）。动物麻醉并机械通气（V=15ml/kg；呼气末正压=3cmH2O；FiO2=1.0）。通过 Hasson 的套管针诱导气腹。在每个 IAP 下，在 1 小时后于初始（IAP，0mmHg）和最终时间点测量变量。在最终时间点，G3 和 G4 中的驱动气道压力（ΔP）和死腔分数（Vd/Vt）高于 G1（p=0.002，差异均值[MD]为 4.60，95%CI：7.91-1.28，p<0.001，MD 为 5.4，95%CI：8.7-2.0；p=0.016，MD-9.5，95%CI：-17.9 至-1.2；p=0.027，MD-8.7，95%CI：-17.1 至-0.4）。G3（p=0.039，MD-11.38，95%CI：-0.07--22.68；p=0.015，MD-13.05，95%CI：-1.74--24.36）和 G4（p=0.039，MD-9.94，95%CI：-0.07 至-19.80；p=0.015，MD-11.43，95%CI：-1.57 至-21.30）的射血分数和短轴缩短率低于 G2。在 G3 中，最大肺血流速度与ΔP 呈负相关（r=-0.740；p=0.018），Vd/Vt 与ΔP 呈正相关（r=0.738，p=0.046）。在 IAP 为 12 和 15mmHg 时，呼吸系统力学受损，左心功能降低，肺动脉最大血流速度无变化。因此，应监测呼吸力学以减少左心功能。
