PURPOSE: Predictors of readmission for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are not well defined. Identifying modifiable predictors may help reduce the burden of readmissions. The study was done to evaluate the role of serum magnesium in frequent readmissions.
METHODS: 100 patients admitted with a diagnosis of AECOPD to a tertiary care center from April 2004 to April 2006 were retrospectively followed from the time of index admission till next admission or death. Number of admissions was calculated for the year after index admission, and frequent readmission was defined as ≥3 per year. Patients with other respiratory diseases, renal failure and congestive heart failure were excluded. Serum magnesium was assayed at the time of admission by bichromatic photometry. Logistic regression analysis was used to find independent risk factors for readmission.
RESULTS: The mean age of patients was 71.9 (±10.9 SD) years. 57 were females. 90% were current or ex smokers. The median duration of time to next admission was 108 (range 2 to 842) days. 87% of patients were readmitted at least once during the first year of follow up and 5% died. 23% had frequent readmissions. 85% had received pneumococcal vaccine within 5 years and 29% received influenza vaccine in the current season. Frequency of readmissions was not influenced by the administration of inhaled or oral steroids, and diuretics at the time of discharge. Vaccination did not protect against frequent readmissions. Serum magnesium was lower in patients with frequent admissions (mean±SD 1.77±0.19 vs 1.86±0.24 mg/dl) and was the sole independent predictor of frequent readmissions (Adjusted Odds Ratio 0.001, 95% Confidence Intervals <0.001 to 0.70; p=0.039).
CONCLUSION: Lower serum magnesium level independently predicts readmission for AECOPD. This is an easily modifiable risk factor.
CLINICAL IMPLICATIONS: Serum magnesium levels should be ascertained in all patients with AECOPD. Further studies are needed to find the effect of long term magnesium supplementation on rate of readmission.
DISCLOSURE: Surya Prakash Bhatt, No Financial Disclosure Information; No Product/Research Disclosure Information