The effects of CO2-insufflation with 5 and 10 mmHg during thoracoscopy on cerebral oxygenation and hemodynamics in piglets: an animal experimental study

Abstract

Objective To evaluate the effect of CO 2 -insufflation with 5 and 10 mmHg on cerebral oxygenation and hemodynamics in neonates. Background An increasing percentage of surgical interventions in neonates are performed by minimal invasive techniques. Recently, concerns have been raised regarding a decrease of cerebral oxygenation in neonates during thoracoscopy as a result of CO 2 -insufflation. Methods This was an animal experimental study. Piglets were anesthetized, intubated, ventilated, and surgically prepared for CO 2 -insufflation. Insufflation was done with 5 or 10 mmHg CO 2 during 1 h. Arterial saturation (SaO 2 ), heart rate (HR), mean arterial blood pressure (MABP), and cerebral oxygenation (rScO 2 ) were monitored. CFTOE, an estimator of cerebral oxygen extraction ((SaO 2 -rScO 2 )/ SaO 2 )), was calculated. Arterial blood gases were drawn every 15 0 : pre (T0), during (T1-T4) and after CO 2 -insufflation (T5). Results Ten piglets (4 kg) were randomized for 5 (P5) and 10 (P10) mmHg CO 2 -insufflation. Two P10 piglets needed resuscitation after insufflation, none P5. Linear mixed-effect modeling of paCO 2 , pH, and SaO 2 showed that values were dependent on time and time squared (p \ 0.001) but were not different between the 5 and 10 mmHg groups. Analysis demonstrated significant changes over time in heart rate and MABP between the 5 and 10 mmHg groups, with a significant higher heart rate and lower blood pressure in the 10 mmHg group (p \ 0.001). For rScO 2 and cFTOE, no group differences could be demonstrated, but a significant effect of time was found: rScO 2 increased and cFTOE decreased (p \ 0.001). Conclusions Insufflation of CO 2 during thoracoscopy with 10 mmHg caused more severe hemodynamic instability and seems to be related with a decrease of cerebral perfusion as represented by a higher oxygen extraction. CO 2 -insufflation of 5 mmHg for thoracoscopy seems to have no adverse effects on cerebral oxygenation.

Insufflation in minimally invasive surgery: Is there any advantage in staying low?

“…We have previously reported the incidence of high EtCO2 in patients undergoing MIS for CDH and OA/TOF repair 15 . Although many reports advise against the use of high insufflation pressures, there are only very few studies examining the effect of various pressures on acidosis, hypercapnia and cerebral oxygenation 19,20 . The only randomised controlled trial on this topic described the negative impact of C02 insufflation on worsening acidosis, especially so in a thoracoscopic repair of CDH 15 .…”

Cardiorespiratory effects of variable pressure thoracic insufflation in cats undergoing video‐assisted thoracic surgery

“…The theory behind this approach is that, by limiting ventilation, PaCO 2 is allowed to increase, so‐called permissive hypercapnia , which may have a sympathomimetic effect. This can cause an increase in heart rate, systemic vasodilation, and an increase in CI that may mitigate detrimental effects on cardiorespiratory function when higher ITP are employed or ventilatory support is not increased to maintain eucapnia . This approach was not used in the cats in this study but would be interesting to investigate in the future.…”

“…This was accompanied by an increase in oxygen consumption and oxygen utilization ratio, suggesting that the effect could be even more detrimental than just the 20% decrease in cardiac index. In other studies of the hemodynamic effects of CDI using experimental animal models or in reports of the use of CDI in humans, effects on CI have been variable. Many of these studies, although not all, used ITP of 5 mm Hg or greater; in humans, much greater ITP is required to provide adequate working space to perform VATS procedures in animals .…”

30 Years of pediatric endoscopic surgery and the challenge goes on

“…To investigate the question, in an animal study, using 4 kg piglets, brain perfusion was compared using 5-and 10-mm insufflation pressures. The use of 5-mm insufflation pressure had no adverse effects of cerebral perfusion [24]. Also in a study on thoracoscopic esophageal atresia repair, insufflation was tolerated in all patients [25].…”