提高无创通气压力支持水平在治疗COPD并急性呼吸衰竭的应用

Effects of Increasing Inspiratory Pressure in COPD patients with Acute Respiratory Failure during NIP-PV

目的比较不同的无创通气压力支持水平对COPD急性加重并呼吸衰竭患者血气分析的影响,探讨能否减少较严重气道阻塞患者建立有创人工气道的可能性及其时机.方法对42例COPD合并急性呼吸衰竭,PaCO2≥70mmHg,并出现神志改变的患者,进行面(鼻)罩压力支持通气治疗.结果①应用较高的压力支持水平(IPAP 25.6±2.4cmH2O)可使71.4% (30例,成功组)患者通气明显改善.PaCO2下降(p<0.05),PaO2升高(p<0.05);②12例(失败组)无创通气12～24小时后症状及血气分析无改善改有创通气.两组在高压力水平通气时均需改用面罩. 结论提高无创通气的压力支持水平,使71.4%患者血气分析改善,避免了建立人工气道.在较高支持压力水平(≥15-18cmH2O)通气时,建议用面罩通气,适时进行有创人工通气.

Objective To investigate the effect of increasing the inspiratory pressure support (IPS) in COPD patients with acute respiratory failure (ARF) .whether it could reducing the need for intubations and the timing of intubations of whom failure responses to NIPPV via nasal / face mask. Methods 42 consecutive COPD patients (M/F 30/12, mean age 63.7±14.4 years) with ARF were enrolled in the study.All patients received the standard therapy and NIPPV with initial IPS≤20 cmH2O for 2 hrs,then increasing the IPS 3≥20cmH2O. Arterial blood gas (ABG) and respiratory mechanics were measured at baseline,IPS≤20 cmH2O (P1) for 2 hrs, IPS≥20cmH2O (P2) for 2 hrs,4hrs and 12 hrs.Results ABC in 42 patients with NIPPV had not changed with P1 for 2 hrs,all p values > 0.05. After increased IPS to 25.1±2.4 cmH2O(P2) , ABG in 30 patients whom defined as the improved group, has significantly improved after 2 hrs and 4 hrs ventilation (PaCO276.1±18.2 vs 55.8±5.7mmHg, PaO256.8±8.8 vs 118 .6±15.2, all p < 0.05) ,all patients in this group were avoided intubations till discharged. Another 12 patients,whom were defined as failure group, pH,PaCO2 and PaO2 have not changed in spite of IPS increasing,all p values were > 0.05. All patients of the group were intubated within 24hrs.Overall,42 patients had to shifted to face masks within the higher IPS.Conclusions In 71.4% (32/40) COPD patients with ARF during NIPPV, increasing IPS combined with regular airway management can reduce the need of intubations, although they failed to respond to the lower IPS. If the patient's condition fails to improve in spite of the increasing of IPS within 6-12 hours, intubation and mechanical ventilation is indicated.