From the Departments of *Pediatric Anesthesiology, †Pediatric General Surgery, ‡Urology, and §Pediatric Anesthesiology and Critical Care, Children's Hospital of Wisconsin, Medical College of Wisconsin, Milwaukee, Wisconsin.
Anesth Analg. 2015 Feb;120(2):349-54. doi: 10.1213/ANE.0000000000000525.
Clinically significant gas embolism during laparoscopy is a rare but potentially catastrophic event. Case reports suggest that air, in addition to the insufflation gas, may be present. We studied the effects of equipment design and flushing techniques on the composition of gas present under experimental and routine pediatric surgical conditions. Concentrations of nitrogen (N2), oxygen (O2), and carbon dioxide (CO2) were measured by Raman spectroscopy in gas delivered to and retrieved from a mock peritoneum during simulated laparoscopy. We then analyzed the composition of insufflated and recovered gases during elective laparoscopic procedures conducted with CO2-preflushed and unflushed tubing to determine the presence of significant (10%) quantities of air. In vitro, CO2 was not detected at the distal end of insufflator tubing until after delivery of approximately 0.2 L of gas, and N2 persisted until >0.4 L was delivered, with 40% ± 8% (mean ± SD, range 33%-49%) recovered from the mock peritoneum at the termination of initial insufflation. In clinical studies, preflushing reduced the initial concentration of N2 from 78% ± 0.5% to 23% ± 15%, but >10% air was detected in all subsequent samples, regardless of insufflation technique. Laparoscopic equipment and practice routinely permit delivery of air to the insufflated cavity. Purging the equipment with CO2 reduces but does not eliminate air (N2, O2) within the peritoneal cavity during laparoscopy. Thus, when vascular injury occurs, embolized gases will contain variable quantities of N2, O2, and CO2. As the initial insufflation volume diminishes and approaches the volume of the insufflation tubing, which occurs in infants and young pediatric patients, the concentration of N2 will approximate that of room air in an unflushed system. Small insufflation volumes containing high N2 concentrations can contribute to catastrophic air emboli in neonates and small pediatric patients.
在腹腔镜检查期间出现有临床意义的气体栓塞是一种罕见但潜在灾难性的事件。病例报告表明，除了注入的气体外，可能还存在空气。我们研究了设备设计和冲洗技术对实验和常规儿科手术条件下存在的气体组成的影响。通过拉曼光谱法测量了模拟腹腔镜检查过程中向模拟腹膜内输送和回收的气体中的氮气（N2）、氧气（O2）和二氧化碳（CO2）的浓度。然后，我们分析了在使用 CO2 预冲洗和未冲洗的管道进行的选择性腹腔镜手术中注入和回收的气体的组成，以确定是否存在大量（10%）的空气。在体外，直到输送了大约 0.2 L 的气体后，才在注气器管道的远端检测到 CO2，并且 N2 持续存在，直到输送了>0.4 L 的气体，在初始注气结束时从模拟腹膜中回收了 40%±8%（平均值±标准差，范围 33%-49%）。在临床研究中，预冲洗将初始 N2 浓度从 78%±0.5%降低至 23%±15%，但无论注气技术如何，在所有后续样本中均检测到>10%的空气。腹腔镜设备和操作通常允许将空气输送到注入的腔中。用 CO2 冲洗设备可减少但不能消除腹腔镜检查期间腹腔内的空气（N2、O2）。因此，当发生血管损伤时，栓塞的气体会包含不同数量的 N2、O2 和 CO2。随着初始充气量减少并接近充气管道的体积，这种情况在婴儿和年幼的儿科患者中发生，未冲洗系统中的 N2 浓度将接近室内空气的浓度。含有高浓度 N2 的小充气量会导致新生儿和小型儿科患者发生灾难性的空气栓塞。
