The Risk Factors With Non-invasive Positive Pressure Ventilation Failure In Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Objective: to evaluate the risk factors associated with failure of non-invasive positive pressure ventilation(NPPV)in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).Methods: We retrospectively evaluated 162 AECOPD patients treated with NPPV.Patients were grouped according to the results into two groups: success group and failure group,univariable analyses were performed on: age,smoking history,gender,body mass index(BMI),breathlessness measurement using the modified British Medical Reseach Council(m MRC),auxiliary respiratory muscle classification,glasgow coma score(GCS),acute physiology and chronic health evaluation(APACHE)? at admission,vital signs at admission,after 1 h and 3h of NPPV treatment: respiratory rate(RR),heart rate(HR),blood routine at admission: white blood cell,hemoglobin,blood biochemistry at admission: total protein,albumin,creatinine,C-reactive protein(CRP),arterial blood gases(p H,Pa O2,Pa CO2,Pa O2/Fi O2)at admission,after 1 h and 3h of NPPV treatment.Results: NPPV was successful in 127(78.4%),failed in 35(21.6%).1.on admission no difference was seen: age,smoking history,gender,BMI,m MRC,auxiliary respiratory muscle classification,GCS.On admission APACHE? score was higher(17.1±4.1 vs.12.5±3.0,point,p=0.000)in the failure group.2.on admission lower serum albumin level(28.9±5.3 vs.35.3±4.6,g/L,p=0.000),and higher serum CRP level(23.2±9.9 vs.19.0±8.8,mg/L,p=0.017)in the failure group.3.RR and HR were higher(RR: 26.8±6.3 vs.21.1±3.8,breaths/min,p=0.000,HR: 123.7±11.2 vs.104.5±13.0,beats/min,p=0.000)after 1h,RR and HR were higher(RR: 31.5±7.4 vs.20.6±4.2,breaths/min,p=0.000,HR: 123.5±10.9 vs.93.3±6.5,beats/min,p=0.000)after 3h in the failure group.4.arterial p H,Pa O2,and Pa O2/Fi O2 were higher(p H: 7.34±0.08 vs.7.29±0.05,p=0.000,Pa O2: 67.2±10.2 vs.61.3±6.8,mm Hg,p=0.000,Pa O2/Fi O2: 239.3±31.2 vs.195.9±22.1,mm Hg,p=0.000)after 1h and were higher(p H: 7.36±0.06 vs.7.30±0.07,p=0.000,Pa O2: 69.1±7.6 vs.62.3±9.4,mm Hg,p=0.000,Pa O2/Fi O2: 243.9±27.7 vs.194.1±23.8,mm Hg,p=0.000)after 3h in the NPPV successful group.Pa CO2 was higher higher(64.2±6.9 vs.55.4±5.1,mm Hg,p=0.000)after 3h in the failure group.Conclusion: on admission lower serum albumin level,high CRP concentration and APACHE ? score,inadequate response in tachypnea,tachycardia,oxygenation status,hypercapnia and acidosis after 1-3 h of NPPV treatment were the risk factors with NPPV failure in AECOPD.