Jones P W, Greenstone M
Division of Physiological Medicine, St George's Hospital Medical School, Cranmer Terrace, Tooting, London, UK, SW17 ORE.
Cochrane Database Syst Rev. 2001;2001(1):CD002881. doi: 10.1002/14651858.CD002881.
Carbonic anhydrase inhibitors such as acetazolamide cause a mild metabolic acidosis and may stimulate breathing. Some patients with severe chronic obstructive pulmonary disease (COPD) develop chronic hypercapnic ventilatory failure. In theory, they may benefit from use of these drugs with a fall in arterial carbon dioxide level (PCO2) and a rise in arterial oxygen (PO2).
To determine the effectiveness and safety of acetazolamide in the treatment of hypercapnic ventilatory failure due to COPD SEARCH STRATEGY: The Cochrane Register of Controlled Clinical Trials was searched along with Medline, Embase, Central and CINAHL for relevant randomised control trials.
Trials were included in the review provided they were placebo controlled, carried out in patients with stable chronic ventilatory failure due to COPD.
Data were extracted and analysed by two reviewers (PJ and MG) and agreement was reached by consensus. Where data could be aggregated they were analysed using a fixed efefcts model and reported as a weighted mean difference (WMD) and its associated 95% confidence interval (95% CI).
Four trials were included in the review. Of these, two were randomised parallel studies, one was a crossover study and the other had a sequential design. A total of 84 patients were involved. Study quality was mixed and the studies were short (typically two weeks). All studies showed a similar direction and size of effect. In the randomised parallel studies, acetazolamide caused a metabolic acidosis and produced a non-significant fall in PCO2 (WMD -0.41 kPa; 95% CI -0.91, 0.09; N=2) and a significant rise in PO2 (WMD 1.54 kPa; 95% CI 0.97, 2.11; N=2). One study reported an improvement in sleep but there were no data concerning outcomes such as health status, symptoms, exacerbation rate, hospital admissions or deaths. Side effects were reported infrequently.
REVIEWER'S CONCLUSIONS: Acetazolamide can produce a small increase in arterial PO2 and fall in PCO2. These conclusions are drawn from a few small short studies that were not all of high quality. It is not known whether this physiological improvement is associated with clinical benefit.
乙酰唑胺等碳酸酐酶抑制剂可导致轻度代谢性酸中毒，并可能刺激呼吸。一些重度慢性阻塞性肺疾病（COPD）患者会出现慢性高碳酸血症性通气衰竭。理论上，使用这些药物可能会使动脉二氧化碳水平（PCO2）下降，动脉血氧（PO2）升高，从而使患者受益。
确定乙酰唑胺治疗COPD所致高碳酸血症性通气衰竭的有效性和安全性。检索策略：检索Cochrane临床对照试验注册库以及Medline、Embase、CENTRAL和CINAHL，查找相关随机对照试验。
纳入的试验需为安慰剂对照试验，研究对象为因COPD导致稳定慢性通气衰竭的患者。
由两名评价员（PJ和MG）提取并分析数据，通过共识达成一致意见。若数据可合并，则采用固定效应模型进行分析，并报告加权平均差（WMD）及其相关的95%置信区间（95%CI）。
本评价纳入了4项试验。其中，2项为随机平行研究，1项为交叉研究，另1项为序贯设计。共有84例患者参与。研究质量参差不齐，且研究时间较短（通常为两周）。所有研究显示的效应方向和大小相似。在随机平行研究中，乙酰唑胺导致代谢性酸中毒，PCO2有非显著性下降（WMD -0.4l kPa；95%CI -0.91，0.09；N = 2），PO2有显著性升高（WMD 1.54 kPa；95%CI 0.97，2.11；N =
2）。一项研究报告睡眠有所改善，但未提供有关健康状况、症状、急性加重率、住院或死亡等结局的数据。不良反应报告较少。
乙酰唑胺可使动脉PO2略有升高，PCO2略有下降。这些结论来自少数几项规模较小、时间较短且并非均为高质量的研究。尚不清楚这种生理改善是否与临床获益相关。
