Uemura Kenichiro, McClaine Rebecca J, de la Fuente Sebastian G, Manson Roberto J, Campbell Kurt A, McClaine Deborah J, White William D, Stamler Jonathan S, Eubanks W Steve, Reynolds James D
Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA.
Anesthesiology. 2004 Dec;101(6):1332-8. doi: 10.1097/00000542-200412000-00013.
Anecdotal reports suggest that the second trimester is the safest time to conduct a laparoscopic procedure on a pregnant patient, but this supposition has not been tested empirically.
Previously instrumented preterm sheep (total n = 8) at gestational day 90 (term, 145 days) were anesthetized and then insufflated with carbon dioxide for 60 min at a pressure of 15 mmHg. Cardiovascular parameters were continuously recorded while blood gas status was determined before and at 15-min intervals during and up to 2 h after insufflation.
Insufflation produced minimal maternal blood gas or cardiovascular changes except for a significant reduction in uterine blood flow. The decrease in perfusion increased fetal arterial blood partial pressure of carbon dioxide and decreased fetal pH, oxygen saturation, and oxygen content; there was also progressive fetal hypotension and bradycardia. After manually deflating the ewe, uterine blood flow returned to normal, and the fetal partial pressure of carbon dioxide and pH changes resolved within 1 h. However, fetal oxygen saturation and content remained depressed, and fetal cardiovascular status continued to decline during the 2-h postinsufflation monitoring period.
Previous studies with near-term sheep determined that carbon dioxide pneumoperitoneum produces respiratory acidosis but does not decrease fetal oxygenation. In contrast, the current findings indicate that in the preterm fetus, insufflation-induced hypercapnia and acidosis are accompanied by prolonged fetal hypoxia and cardiovascular depression. This result suggests that additional work should be conducted to confirm the presumed safety of conducting minimally invasive procedures during the second trimester.
轶事报道表明，孕中期是对孕妇进行腹腔镜手术最安全的时期，但这一假设尚未得到实证检验。
对90日龄（足月为145天）已植入仪器的早产绵羊（共8只）进行麻醉，然后以15 mmHg的压力充入二氧化碳60分钟。在充气期间及充气后长达2小时内，每隔15分钟测定一次血气状态，同时持续记录心血管参数。
除子宫血流量显著减少外，充气对母体血气或心血管变化影响极小。灌注减少使胎儿动脉血二氧化碳分压升高，胎儿pH值、氧饱和度和氧含量降低；还出现了胎儿渐进性低血压和心动过缓。人工给母羊放气后，子宫血流量恢复正常，胎儿二氧化碳分压和pH值变化在1小时内得到缓解。然而，胎儿氧饱和度和氧含量仍处于较低水平，在充气后2小时的监测期内胎儿心血管状态持续下降。
先前对近足月绵羊的研究表明，二氧化碳气腹会导致呼吸性酸中毒，但不会降低胎儿氧合。相比之下，当前研究结果表明，对于早产胎儿，充气引起的高碳酸血症和酸中毒会伴有胎儿长期缺氧和心血管抑制。这一结果表明，应开展更多工作以证实孕中期进行微创手术的假定安全性。
