Müller N, Herberg U, Breuer J, Kratz T, Härtel J A
Department for Pediatric Cardiology, Children's Heart Center UK Bonn, University Hospital Bonn, Bonn, Germany.
Department for Pediatric Cardiology, University Hospital Aachen, Aachen, Germany.
Front Cardiovasc Med. 2023 Jun 23;10:1170275. doi: 10.3389/fcvm.2023.1170275. eCollection 2023.
At cruising altitude, the cabin pressure of passenger aircraft needs to be adjusted and, therefore, the oxygen content is equivalent to ambient air at 2,500 masl, causing mild desaturation and a rising pulmonary vascular resistance (PVR) in healthy subjects. For Fontan patients with passive pulmonary perfusion, a rising PVR can cause serious medical problems. The purpose of this fitness to fly investigation (FTF) is to assess the risk of air travel for children and adolescents after Fontan palliation.
We investigated 21 Fontan patients [3-14y] in a normobaric hypoxic chamber at a simulated altitude of 2,500 m for 3 h. Oxygen saturation, heart rate, and regional tissue saturation in the forehead (NIRS) were measured continuously. Before entering the chamber, after 90 and 180 min in the hypoxic environment, blood gas analysis and echocardiography were performed.
Heart rate and blood pressure did not show significant intraindividual changes. Capillary oxygen saturation (SaO) decreased significantly after 90 min by a mean of 5.6 ± 2.87% without further decline. Lactate, pH, base excess, and tissue saturation in the frontal brain did not reach any critical values. In the case of open fenestration between the tunnel and the atrium delta, P did not increase, indicating stable pulmonary artery pressure.
All 21 children finished the investigation successfully without any adverse events, so flying short distance seems to be safe for most Fontan patients with good current health status. As the baseline oxygen saturation does not allow prediction of the maximum extent of desaturation and adaption to a hypoxic environment takes up to 180 min, the so-called hypoxic challenge test is not sufficient for these patients. Performing an FTF examination over a period of 180 min allows for risk assessment and provides safety to the patients and their families, as well as the airline companies.
在巡航高度,客机机舱压力需要进行调节,因此氧气含量相当于海拔2500米处的环境空气,这会导致健康受试者出现轻度氧饱和度下降和肺血管阻力(PVR)升高。对于采用被动肺灌注的Fontan手术患者,PVR升高会引发严重的医疗问题。这项飞行适宜性调查(FTF)的目的是评估Fontan姑息治疗后儿童和青少年航空旅行的风险。
我们在常压低氧舱中对21名Fontan手术患者[3 - 14岁]进行了研究,模拟海拔2500米的环境,持续3小时。连续测量氧饱和度、心率和前额区域组织饱和度(近红外光谱法)。在进入舱室前、低氧环境中90分钟和180分钟后,进行血气分析和超声心动图检查。
心率和血压在个体内未显示出显著变化。90分钟后,毛细血管氧饱和度(SaO)显著下降,平均下降5.6±2.87%,且未进一步下降。乳酸、pH值、碱剩余和额叶脑组织饱和度均未达到任何临界值。在隧道与心房三角洲之间存在开放窗孔的情况下,肺动脉压力未升高,表明肺动脉压力稳定。
所有21名儿童均成功完成调查,未发生任何不良事件,因此对于目前健康状况良好的大多数Fontan手术患者而言,短途飞行似乎是安全的。由于基线氧饱和度无法预测氧饱和度下降的最大程度,且适应低氧环境需要长达180分钟,因此所谓的低氧激发试验对这些患者并不充分。进行为期180分钟的FTF检查可进行风险评估,并为患者及其家属以及航空公司提供安全保障。