Department of Pediatric Surgery, Erasmus University Medical Centre, PO Box 2060, 3000 CB Rotterdam, The Netherlands.
Surg Endosc. 2013 May;27(5):1668-73. doi: 10.1007/s00464-012-2654-0. Epub 2012 Dec 13.
Several factors may affect volume and dimensions of the working space in laparoscopic surgery. The precise impact of these factors has not been well studied. In a porcine model, we used computed tomographic (CT) scanning for measuring working space volume and distances. In a first series of experiments, we studied the relationship between intra-abdominal pressure (IAP) and working space.
Eleven 20 kg pigs were studied under standardized anesthesia and volume-controlled ventilation. Cardiorespiratory parameters were monitored continuously, and blood gas samples were taken at different IAP levels. Respiratory rate was increased when ETCO₂ exceeded 7 kPa. Breath-hold CT scans were made at IAP levels of 0, 5, 10, and 15 mmHg. Insufflator volumes were compared to CT-measured volumes. Maximum dimensions of pneumoperitoneum were measured on reconstructed CT images.
Respiratory rate had to be increased in three animals. Mild hypercapnia and acidosis occurred at 15 mmHg IAP. Peak inspiratory pressure rose significantly at 10 and 15 mmHg. CT-measured volume increased relatively by 93 % from 5 to 10 mmHg IAP and by 19 % from 10 to 15 mmHg IAP. Comparing CT volumes to insufflator volumes gave a bias of 76 mL. The limits of agreement were -0.31 to +0.47, a range of 790 mL. The internal anteroposterior diameter increased by 18 % by increasing IAP from 5 to 10 mmHg and by 5 % by increasing IAP from 10 to 15 mmHg. At 15 mmHg, the total relative increase of the pubis-diaphragm distance was only 6 %. Abdominal width did not increase.
CT allows for precise calculation of the actual CO₂ pneumoperitoneum volume, whereas the volume of CO₂ released by the insufflator does not. Increasing IAP up to 10 mmHg achieved most gain in volume and in internal anteroposterior diameter. At an IAP of 10 mmHg, higher peak inspiratory pressure was significantly elevated.
多种因素可能会影响腹腔镜手术的工作空间的体积和尺寸。这些因素的确切影响尚未得到充分研究。在猪模型中，我们使用计算机断层扫描（CT）扫描来测量工作空间的体积和距离。在一系列初步实验中，我们研究了腹腔内压（IAP）与工作空间之间的关系。
11 头 20 公斤重的猪在标准化麻醉和容量控制通气下进行研究。连续监测心肺参数，并在不同的 IAP 水平采集血气样本。当 ETCO₂超过 7 kPa 时，增加呼吸频率。在 IAP 水平为 0、5、10 和 15 mmHg 时进行呼气暂停 CT 扫描。比较测压计测量的体积与 CT 测量的体积。在重建的 CT 图像上测量气腹的最大尺寸。
在 3 头动物中必须增加呼吸频率。在 15 mmHg IAP 时发生轻度高碳酸血症和酸中毒。在 10 和 15 mmHg 时，峰压明显升高。CT 测量的体积从 5 mmHg IAP 增加到 10 mmHg IAP 增加了 93%，从 10 mmHg IAP 增加到 15 mmHg IAP 增加了 19%。将 CT 体积与测压计体积进行比较，得到 76 mL 的偏差。一致性区间为 -0.31 至 +0.47，范围为 790 mL。IAP 从 5 mmHg 增加到 10 mmHg 时，内部前后直径增加了 18%，从 10 mmHg 增加到 15 mmHg 时增加了 5%。在 15 mmHg 时，耻骨膈肌距离的总相对增加仅为 6%。腹部宽度没有增加。
CT 可精确计算实际 CO₂气腹的体积，而测压计释放的 CO₂体积则不然。将 IAP 增加到 10 mmHg 可最大程度地增加体积和内部前后直径。在 IAP 为 10 mmHg 时，吸气峰压明显升高。
