Department of Specialistic, Diagnostic and Experimental Medicine (DIMES), Respiratory and Critical Care, University of Bologna, Sant'Orsola Malpighi Hospital building #15, Alma Mater Studiorum, via Massarenti n,15, Bologna 40185, Italy.
BMC Pulm Med. 2014 Feb 13;14:19. doi: 10.1186/1471-2466-14-19.
Identifying the predictors of noninvasive ventilation (NIV) failure has attracted significant interest because of the strong link between failure and poor outcomes. However, very little attention has been paid to the timing of the failure. This narrative review focuses on the causes of NIV failure and risk factors and potential remedies for NIV failure, based on the timing factor.
The possible causes of immediate failure (within minutes to <1 h) are a weak cough reflex, excessive secretions, hypercapnic encephalopathy, intolerance, agitation, and patient-ventilator asynchrony. The major potential interventions include chest physiotherapeutic techniques, early fiberoptic bronchoscopy, changing ventilator settings, and judicious sedation. The risk factors for early failure (within 1 to 48 h) may differ for hypercapnic and hypoxemic respiratory failure. However, most cases of early failure are due to poor arterial blood gas (ABGs) and an inability to promptly correct them, increased severity of illness, and the persistence of a high respiratory rate. Despite a satisfactory initial response, late failure (48 h after NIV) can occur and may be related to sleep disturbance.
Every clinician dealing with NIV should be aware of these risk factors and the predicted parameters of NIV failure that may change during the application of NIV. Close monitoring is required to detect early and late signs of deterioration, thereby preventing unavoidable delays in intubation.
由于无创通气（NIV）失败与不良结局之间存在很强的关联，因此识别 NIV 失败的预测因素引起了广泛关注。然而，人们很少关注失败的时间因素。本叙述性综述重点关注基于时间因素的 NIV 失败的原因、风险因素以及 NIV 失败的潜在补救措施。
即刻失败（数分钟至<1 小时内）的可能原因包括咳嗽反射减弱、分泌物过多、高碳酸血症性脑病、不耐受、烦躁不安和人机不同步。主要的潜在干预措施包括胸部物理治疗技术、早期纤维支气管镜检查、改变呼吸机设置和合理镇静。高碳酸血症性和低氧血症性呼吸衰竭的早期失败（1 至 48 小时内）的风险因素可能不同。然而，大多数早期失败是由于动脉血气（ABG）较差且无法迅速纠正、疾病严重程度增加以及高呼吸频率持续存在所致。尽管初始反应令人满意，但仍可能发生晚期失败（NIV 后 48 小时），这可能与睡眠障碍有关。
每个处理 NIV 的临床医生都应该了解这些风险因素以及 NIV 应用过程中可能发生变化的 NIV 失败的预测参数。需要密切监测以发现早期和晚期恶化的迹象，从而避免不可避免的插管延迟。
