患者加热过度：对骨科手术室通风性能的影响。

Patient warming excess heat: the effects on orthopedic operating room ventilation performance.

机构信息

Department of Anesthesiology, University of Minnesota, Minneapolis, MN, USA.

出版信息

Anesth Analg. 2013 Aug;117(2):406-11. doi: 10.1213/ANE.0b013e31825f81e2. Epub 2012 Jul 19.

DOI:10.1213/ANE.0b013e31825f81e2

PMID:22822191

Abstract

BACKGROUND

Patient warming has become a standard of care for the prevention of unintentional hypothermia based on benefits established in general surgery. However, these benefits may not fully translate to contamination-sensitive surgery (i.e., implants), because patient warming devices release excess heat that may disrupt the intended ceiling-to-floor ventilation airflows and expose the surgical site to added contamination. Therefore, we studied the effects of 2 popular patient warming technologies, forced air and conductive fabric, versus control conditions on ventilation performance in an orthopedic operating room with a mannequin draped for total knee replacement.

METHODS

Ventilation performance was assessed by releasing neutrally buoyant detergent bubbles ("bubbles") into the nonsterile region under the head-side of the anesthesia drape. We then tracked whether the excess heat from upper body patient warming mobilized the "bubbles" into the surgical site. Formally, a randomized replicated design assessed the effect of device (forced air, conductive fabric, control) and anesthesia drape height (low-drape, high-drape) on the number of bubbles photographed over the surgical site.

RESULTS

The direct mass-flow exhaust from forced air warming generated hot air convection currents that mobilized bubbles over the anesthesia drape and into the surgical site, resulting in a significant increase in bubble counts for the factor of patient warming device (P < 0.001). Forced air had an average count of 132.5 versus 0.48 for conductive fabric (P = 0.003) and 0.01 for control conditions (P = 0.008) across both drape heights. Differences in average bubble counts across both drape heights were insignificant between conductive fabric and control conditions (P = 0.87). The factor of drape height had no significant effect (P = 0.94) on bubble counts.

CONCLUSIONS

Excess heat from forced air warming resulted in the disruption of ventilation airflows over the surgical site, whereas conductive patient warming devices had no noticeable effect on ventilation airflows. These findings warrant future research into the effects of forced air warming excess heat on clinical outcomes during contamination-sensitive surgery.

摘要

背景

基于在普通外科手术中确立的益处，患者保暖已成为预防意外低体温的标准护理措施。然而，这些益处可能并不能完全转化为对污染敏感的手术（即植入物），因为患者保暖设备会释放多余的热量，这可能会扰乱预期的天花板到地板的通风气流，并使手术部位暴露于额外的污染中。因此，我们研究了两种流行的患者保暖技术（强制空气和导电织物）与控制条件对使用全膝关节置换术覆盖的模型的骨科手术室通风性能的影响。

方法

通过将中性浮力清洁剂泡沫（“泡沫”）释放到麻醉罩头侧的非无菌区域来评估通风性能。然后，我们跟踪来自上身患者保暖的多余热量是否将“泡沫”移到手术部位。具体来说，随机重复设计评估了设备（强制空气、导电织物、对照）和麻醉罩高度（低罩、高罩）对拍摄到手术部位的泡沫数量的影响。

结果

强制空气保暖的直接质量流量排气产生了热空气对流，使泡沫在麻醉罩上移动并进入手术部位，导致患者保暖设备因素的泡沫计数显著增加（P < 0.001）。在两种罩高度下，强制空气的平均计数为 132.5，而导电织物为 0.48（P = 0.003），对照条件为 0.01（P = 0.008）。在两种罩高度下，导电织物和对照条件之间的平均泡沫计数差异不显著（P = 0.87）。罩高度因素对泡沫计数没有显著影响（P = 0.94）。