Inhaled Menthol for Dyspnea Relief During Cycle Exercise in COPD: A Randomized Trial.

Proposed mechanisms include stimulation of cold receptors in the upper airways, modulating perception of breathing-related effort and airflow.

提出的机制包括刺激上呼吸道的冷感受器，调节呼吸相关努力和气流的感知。

research_question

Does MI also alleviate exertional dyspnea in COPD?

MI也能缓解COPD患者的劳力性呼吸困难吗？

study_design_and_methods

Twenty patients with COPD (60% male; mean age ± SD, 68 ± 6 years; FEV1, 47% ± 17% predicted) completed 2 constant-load cycle exercise tests (73% ± 7% peak power output) to exhaustion with menthol or placebo (strawberry flavoring) added to the breathing circuit in counterbalanced order and on separate days.

20名COPD患者（男性占60%；平均年龄±标准差，68±6岁；FEV1为预测值的47%±17%）完成了2次恒定负荷的循环运动测试（峰值功率输出的73%±7%），直至力竭，测试中通过呼吸回路添加了薄荷或安慰剂（草莓香精），顺序和测试日是平衡的。

Ventilatory and neuromuscular parameters were measured continuously.

持续测量通气和神经肌肉参数。

Dyspnea intensity was serially assessed using the 0 to 10 category ratio Borg scale, and dyspnea unpleasantness and related sensory qualities were assessed using the Multidimensional Dyspnea Profile at end exercise.

使用0至10级比尔格量表连续评估呼吸困难强度，并在运动结束时使用多维呼吸困难量表评估呼吸困难的不愉快感及相关感觉特性。

Participants were asked in which test their inspiratory airflow felt easier.

参与者被询问在哪项测试中他们的吸气气流感觉更顺畅。

Results

Serial dyspnea intensity ratings were lower with menthol vs placebo (estimate [Δ/10% peak time]: -0.09; 95% CI, -0.15 to -0.02; P = .01), whereas ratings of dyspnea unpleasantness, air hunger, and mental breathing effort were lower at end exercise (all P < .05).

与安慰剂相比，薄荷醇的连续呼吸困难强度评分较低（估计[Δ/10%峰值时间]：-0.09；95%置信区间，-0.15至-0.02；P = .01），而在运动结束时，呼吸困难的不愉快感、空气饥饿感和精神呼吸努力的评分较低（所有P < .05）。

Menthol-related improvements in dyspnea intensity at symptom limitation of the shorter test vs equivalent time on the other were correlated with higher endurance time (r = -0.73, P < .001).

在症状限制的较短测试中，与另一测试的等效时间相比，薄荷醇相关的呼吸困难强度改善与更高的耐力时间相关（r = -0.73, P < .001）。

There were no differences in ventilatory and neuromuscular parameters (P > .05).

在通气和神经肌肉参数上没有差异（P > .05）。

Exercise endurance time was unaffected by menthol (Δ 0.3 ± 1.6 minutes with menthol vs placebo; P = .50).

运动耐力时间未受薄荷醇影响（薄荷醇与安慰剂相比，Δ 0.3 ± 1.6分钟；P = .50）。

A total of 85% reported easier inspiratory airflow with menthol.

85%的受试者报告使用薄荷醇后吸气气流变得更顺畅。

interpretation

MI may be useful for management of exertional dyspnea in selected patients with COPD.

对于选定的慢性阻塞性肺疾病（COPD）患者，心肌梗死（MI）可能有助于管理劳力性呼吸困难。

Future work should investigate if MI can improve outcomes of exercise rehabilitation programs.

未来的研究应调查心肌梗死（MI）是否能改善运动康复计划的结果。

clinical_trial_registration

ClinicalTrials.gov; No.: NCT05785026; URL: www.

ClinicalTrials.gov; 编号: NCT05785026; 网址: www.

clinicaltrials

gov.

5年总生存率为78%（95%置信区间，73%-83%）。