无创正压通气治疗慢性阻塞性肺疾病所致严重呼吸衰竭失败的相关因素

①目的 了解无创正压通气（NIPPV）治疗慢性阻塞性肺疾病（COPD）所致严重呼吸衰竭失败相关因素，探讨NIPPV治疗失败需转换为有创通气时机。②方法 对67例COPD所致严重呼吸衰竭病人进行NIPPV治疗，根据治疗结果分为NIPPV失败组和NIPPV成功组，比较两组病人的各项指标变化，分析其与NIPPV治疗失败相关的因素。③结果 NIPPV失败组25例（37.31％），入院初的动脉血氧分压（PaO2）、pH值低于NIPPV成功组，二氧化碳分压（PaCO2）高于NIPPV成功组，差异有显著意义（t=4.13～6.87，P〈0.05）。Logistic回归分析显示，PaO2〈6.0kPa，PaCO2〉10.0kPa，pH〈7.10是导致NIPPV治疗失败的相关因素。NIPPV失败组治疗后6h内动脉PaO2、PaCO2和pH与治疗前比较无明显改善，而成功组则显示有明显改善（t=3.49～6.35，P〈0.05）。④结论 COPD所致严重呼吸衰竭病人显著异常的PaO2、PaCO2和pH是导致NIPPV治疗失败相关的因素。NIPPV治疗初期（6h内）动脉血气有无显著改善亦可作为预测NIPPV治疗成功与否的指标。

RELEVANT FACTORS OF NON-INVASIVE POSITIVE PRESSURE VENTILATION FAILURE IN THE COPD PATIENTS WITH SEVERE RESPIRATORY FAILURE

Objective To study the failure-related factors in the treatment of severe respiratory failure due to chronic obstructive pulmonary disease (COPD) using non-invasive positive pressure ventilation (NIPPV), and to find the time that NIPPV be replaced by invasive ventilation when NIPPV failure occurs. Methods Sixty-seven patients with severe respiratory failure due to COPD were investigated and divided into NIPPV failure group and NIPPV success group. Physiological and clinical parameters were studied comparatively between two groups. Factors associated with failure of NIPPV were analyzed. Results Failure rate of NIPPV was 37.31% (25/67). PaCO_2 were higher ,and PaO_2 and pH were lower significantly in patients in NIPPV failure group, compared with NIPPV success group (t=4.13-6.87,P<0.05). Logistic regression analysis showed that the NIPPV failure was significantly associated with PaO_2<6.0 kPa, PaCO_2>10.0 kPa and pH<7.10. In NIPPV success group, there was obvious improvement of PaO_2, PaCO_2 and pH at two and six hours after NIPPV therapy compared with baseline (t=3.49-6.35,P<(0.05)). In NIPPV failure group, there was not statistical difference in arterial blood gas between after and before NIPPV therapy. (Conclusion NIPPV) failure in patients with severe respiratory failure due to COPD is influenced by markedly abnormal PaO_2, PaCO_2 and pH. Improvement of arterial blood gas within 6 hours after NIPPV is an index for predicting the success of the treatment.