Department of Surgery, University of Cincinnati, Cincinnati, OH, USA.
J Trauma Acute Care Surg. 2012 Jul;73(1):80-6. doi: 10.1097/TA.0b013e31824cf215.
Bacterial growth in soft tissue and open fractures is a known risk factor for tissue loss and complications in contaminated musculoskeletal wounds. Current care for battlefield casualties with soft tissue and musculoskeletal wounds includes tactical and strategic aeromedical evacuation (AE). This exposes patients to a hypobaric, hypoxic environment. In this study, we sought to determine whether exposure to AE alters bacterial growth in contaminated complex musculoskeletal wounds and whether supplemental oxygen had any effect on wound infections during simulated AE.
A caprine model of a contaminated complex musculoskeletal wound was used. Complex musculoskeletal wounds were created and inoculated with bioluminescent Pseudomonas aeruginosa. Goats were divided into three experimental groups: ground control, simulated AE, and simulated AE with supplemental oxygen. Simulated AE was induced in a hypobaric chamber pressurized to 8,800 feet for 7 hours. Bacterial luminescence was measured using a photon counting camera at three time points: preflight (20 hours postsurgery), postflight (7 hours from preflight and 27 hours postsurgery), and necropsy (24 hours from preflight and 44 hours postsurgery).
There was a significant increase in bacterial growth in the AE group compared with the ground control group measured postflight and at necropsy. Simulated AE induced hypoxia with oxygen saturation less than 93%. Supplemental oxygen corrected the hypoxia and significantly reduced bacterial growth in wounds at necropsy.
Hypoxia induced during simulated AE enhances bacterial growth in complex musculoskeletal wounds which can be prevented with the application of supplemental oxygen to the host.
软组织和开放性骨折中的细菌生长是受污染的肌肉骨骼创伤中组织损失和并发症的已知风险因素。目前，对软组织和肌肉骨骼创伤的战场伤员的护理包括战术和战略航空医疗后送（AE）。这使患者暴露于低压、低氧环境中。在这项研究中，我们试图确定 AE 是否会改变受污染的复杂肌肉骨骼创伤中的细菌生长，以及补充氧气是否会对模拟 AE 期间的伤口感染产生任何影响。
使用受污染的复杂肌肉骨骼创伤的山羊模型。在复杂的肌肉骨骼创伤中接种生物发光铜绿假单胞菌。山羊分为三组实验：地面控制组、模拟 AE 组和模拟 AE 加补充氧气组。在减压室中以 8800 英尺的压力加压 7 小时，诱导模拟 AE。使用光子计数相机在三个时间点测量细菌发光：飞行前（手术后 20 小时）、飞行后（距离飞行前 7 小时，手术后 27 小时）和解剖时（距离飞行前 24 小时，手术后 44 小时）。
与地面控制组相比，AE 组在飞行后和解剖时的细菌生长明显增加。模拟 AE 诱导的缺氧使氧饱和度低于 93%。补充氧气纠正了缺氧，并在解剖时显著减少了伤口中的细菌生长。
模拟 AE 期间诱导的缺氧会增强复杂肌肉骨骼创伤中的细菌生长，而通过向宿主应用补充氧气可以预防这种情况。
