Corrado A, De Paola E, Gorini M, Messori A, Bruscoli G, Nutini S, Tozzi D, Ginanni R
Dipartimento di Pneumologia, Ospedale di Careggi, Firenze, Italy.
Thorax. 1996 Nov;51(11):1077-82. doi: 10.1136/thx.51.11.1077.
In recent years non-invasive ventilatory techniques have been used successfully in the treatment of acute on chronic respiratory failure (ACRF), but careful selection of patients is essential and a comatose state may represent an exclusion criterion. The aim of this retrospective and uncontrolled study was to evaluate whether a non-invasive ventilatory technique such as the iron lung could also be used successfully in patients with hypoxic hypercapnic coma, thus widening the range for application of non-invasive ventilatory techniques.
A series of 150 consecutive patients with ACRF and hypoxic hypercapnic coma admitted to our respiratory intensive care unit were evaluated retrospectively. The most common underlying condition was chronic obstructive pulmonary disease (79%). On admission a severe hypoxaemia (Pao2 5.81 (3.01) kPa) and hypercapnia (Paco2 14.88 (2.78) kPa) associated with a decompensated acidosis (pH 7.13 (0.13)) were present, the Glasgow coma score ranged from 3 to 8, and the mean APACHE II score was 31.6 (5.3). All patients underwent intermittent negative pressure ventilation with the iron lung. The study end point was based on a dichotomous classification of treatment failure (defined as death or need for endotracheal intubation) versus therapeutic success.
There were 45 treatment failures (30%) and 36 deaths (24%). Nine patients (6%) required intubation because of lack of airway control. The median total duration of ventilation was 27 hours per patient (range 2-274). The 105 successfully treated cases recovered consciousness after a median of four hours (range 1-90) of continuous ventilatory treatment and were discharged after 12.1 (9.0) days.
These results show that, in patients with acute on chronic respiratory failure and hypoxic hypercapnic coma, the iron lung resulted in a high rate of success. As this study has the typical limitations of all retrospective and uncontrolled studies, the results need to be formally confirmed by controlled prospective studies. Confirmation of these results could widen the range of application of non-invasive ventilatory techniques.
近年来，无创通气技术已成功用于治疗慢性呼吸衰竭急性加重（ACRF），但仔细选择患者至关重要，昏迷状态可能是一项排除标准。这项回顾性非对照研究的目的是评估诸如铁肺之类的无创通气技术是否也能成功用于缺氧性高碳酸血症昏迷患者，从而扩大无创通气技术的应用范围。
对连续收治入我们呼吸重症监护病房的150例ACRF合并缺氧性高碳酸血症昏迷患者进行回顾性评估。最常见的基础疾病是慢性阻塞性肺疾病（79%）。入院时存在严重低氧血症（动脉血氧分压5.81（3.01）kPa）、高碳酸血症（动脉血二氧化碳分压14.88（2.78）kPa）以及失代偿性酸中毒（pH值7.13（0.13）），格拉斯哥昏迷评分3至8分，急性生理与慢性健康状况评分系统II（APACHE II）平均评分为31.6（5.3）。所有患者均使用铁肺进行间歇性负压通气。研究终点基于治疗失败（定义为死亡或需要气管插管）与治疗成功的二分法分类。
有45例治疗失败（30%），36例死亡（24%）。9例患者（6%）因气道控制不佳需要插管。每位患者通气总时长的中位数为27小时（范围2至274小时）。105例成功治疗的病例在持续通气治疗中位数4小时（范围1至90小时）后恢复意识，12.1（9.0）天后出院。
这些结果表明，对于慢性呼吸衰竭急性加重合并缺氧性高碳酸血症昏迷患者，铁肺取得了较高的成功率。由于本研究具有所有回顾性非对照研究的典型局限性，结果需要通过对照前瞻性研究进行正式确认。这些结果若得到确认，可能会扩大无创通气技术的应用范围。
