Acute Exacerbation of Chronic Obstructive Pulmonary Disease: Predictors of Outcome

Background:Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is considered to be an important cause of morbidity, intensive care unit (ICU) admissionand mortality in COPD patients.
Objectives:to identify the factors which could predict the outcome ofCOPDpatients.
Patients and methods: A prospective study was conducted at Chest Department of Sohag University Hospital during the period from May 2016 to August 2017 and included 101 COPD patients with AECOPD. Patients were deemed to have AECOPD if this diagnosis appeared on their clinical histories. The studied variables included clinical parameters (symptoms & signs), spirometry and laboratory tests (complete blood count, serum creatinine, liver function tests -ALT, AST and serum albumin- serum electrolytes, arterial blood gas test and sputum cultures), radiological data(plain chest x-ray, CT chest (if indicated) and echocardiographic data for every patient. The outcome in the studyincluded improvement or non-improvement (referral to ICU or death).
Results:The study included 101 patients with AECOPD, the mean age of the patients was 60years, 66.34% of them were males and 33.66% females, according tothe outcome; 83 cases improved, 18 cases had poor outcome (i.e. need ICU admissionordied). Bacterial growth, in the sputum culture, was recorded in 65.35% of the cases. The most frequently recorded bacterial organism were: Streptococcus pneumonia, Haemophilus influenza and Pseudomonas aeruginosa (14.85%, 13.87% and 10.89% respectively). The factors, which had significant relation to poor outcome, were: male gender (P=0.04), frequent exacerbation (P=0.003), history of ≥2 hospital admission and previous ICU admission in the last year(P= 0.004 and 0.003 in order), history of prior LTOT(P=0.006),altered consciousness, tachycardia, tachypnea, fever, flapping tremor, pedal edema (P=0.009, 0.02, ˂0.0001, 0.03,˂0.0001and0.008 in order), associated comorbidities (bronchiectasis, corpulmonale and DM; P=0.047, 0.005 and 0.008respectively), lower mean values of pH, PaO₂, SaO₂ and higher mean values of PaCO₂ on admission (P=0.007, 0.003, 0.001 and 0.01in order), leukocytosis, thrombocytopenia, elevated serum creatinine, elevated liver enzymes and hypoalbuminemia (P= 0.008, 0.001, 0.02, 0.001and0.007 in order), presence of cardiomegaly or bronchiectaic changes as radiological findings (P= 0.001 and 0.047 in order), severe pulmonary artery hypertension as an echocardiographic finding (P=0.03), lower mean values of FEV1and FVC(P=0.01 and 0.02 in order), Staph. aureusand P. aeruginosa isolation in sputum cultures (P˂0.0001 and 0.002 in order).
Conclusion:The significant factors in predicting poor outcome of AECOPD were: male gender, frequent exacerbations, prior hospital (≥2 hospital admission/year) and ICU admission in the last year, history of prior LTOT, associated comorbidities (bronchiectasis,corpulmonale and DM), consciousness alteration, tachycardia, tachypnea, fever, flapping tremor, lower limb edema, arterial blood gas parameters on admission (higher mean values of PaCO₂ and lower mean values of pH, PaO₂ and SaO₂), leukocytosis, thrombocytopenia, elevated serum creatinine, higher mean levels of ALT and AST, hypoalbuminemia, presence of cardiomegaly or bronchiectatic changes as radiological findings, severe pulmonary artery hypertension as an echocardiographic finding, lower mean values of FEV₁ and FVC, P.aeruginosa and Staph.aureus isolation in sputum cultures.