Study objective

Drugs stored in rescue helicopters may be subject to extreme environmental conditions. The aim of this study was to measure whether drugs stored under the real-life conditions of a Swiss helicopter emergency medical service (HEMS) would retain their potency over the course of 1 year.

Methods

A prospective, longitudinal study measuring the temperature exposure and concentration of drugs stored on 2 rescue helicopters in Switzerland over 1 year. The study drugs included epinephrine, norepinephrine, amiodarone, midazolam, fentanyl, naloxone, rocuronium, etomidate, and ketamine. Temperatures were measured inside the medication storage bags and the crew cabins at 10-minute intervals. Drug stability was measured on a monthly basis over the course of 12 months using high-performance liquid chromatography. The medications were considered stable at a minimum remaining drug concentration of 90% of the label claim.

Results

Temperatures ranged from −1.2 °C to 38.1 °C (29.84 °F to 100.58 °F) inside the drug storage bags. Of all the temperature measurements inside the drug storage bags, 37% lay outside the recommended storage conditions. All drugs maintained a concentration above 90% of the label claim. The observation periods for rocuronium and etomidate were shortened to 7 months because of a supply shortage of reference samples.

Conclusion

Drugs stored under the real-life conditions of Swiss HEMS are subjected to temperatures outside the manufacturer’s approved storage requirements. Despite this, all drugs stored under these conditions remained stable throughout our study. Real-life stability testing could be a way to extend drug exchange intervals.

中文翻译：

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储存在直升机中供紧急医疗服务使用的药物的稳定性：一项前瞻性观察研究

学习目标

储存在救援直升机中的药物可能会受到极端环境条件的影响。本研究的目的是测量在瑞士直升机紧急医疗服务 (HEMS) 的真实条件下储存的药物是否会在 1 年内保持其效力。

方法

一项前瞻性纵向研究，测量瑞士 2 架救援直升机 1 年内储存的药物的温度暴露和浓度。研究药物包括肾上腺素、去甲肾上腺素、胺碘酮、咪达唑仑、芬太尼、纳洛酮、罗库溴铵、依托咪酯和氯胺酮。每隔 10 分钟测量一次药物储存袋和船员舱内的温度。使用高效液相色谱法在 12 个月的过程中每月测量药物稳定性。这些药物被认为是稳定的，最低剩余药物浓度为标签声明的 90%。

结果

药物储存袋内的温度范围为 -1.2°C 至 38.1°C（29.84°F 至 100.58°F）。在药物储存袋内的所有温度测量中，有 37% 位于推荐的储存条件之外。所有药物的浓度都保持在标签声明的 90% 以上。由于参考样品供应短缺，罗库溴铵和依托咪酯的观察期缩短至7个月。

结论

在瑞士 HEMS 的真实条件下储存的药物会经受超出制造商批准的储存要求的温度。尽管如此，在我们的研究过程中，在这些条件下储存的所有药物都保持稳定。现实生活中的稳定性测试可能是延长药物更换间隔的一种方式。