Anemia and performance status as prognostic markers in acute hypercapnic respiratory failure due to chronic obstructive pulmonary disease

Abstract

BackgroundIn patients with acute hypercapnic respiratory failure (AHRF) during exacerbations of COPD, mortality can be high despite noninvasive ventilation (NIV). For some, AHRF is terminal and NIV is inappropriate. However there is no definitive method of identifying patients who are unlikely to survive. The aim of this study was to identify factors associated with inpatient mortality from AHRF with respiratory acidosis due to COPD.MethodsCOPD patients presenting with AHRF and who were treated with NIV were studied prospectively. The forced expiratory volume in 1 second (FEV1), World Health Organization performance status (WHO-PS), clinical observations, a composite physiological score (Early Warning Score), routine hematology and biochemistry, and arterial blood gases prior to commencing NIV, were recorded.ResultsIn total, 65 patients were included for study, 29 males and 36 females, with a mean age of 71 ± 10.5 years. Inpatient mortality in the group was 33.8%. Mortality at 30 days and 12 months after admission were 38.5% and 58.5%, respectively. On univariate analysis, the variables associated with inpatient death were: WHO-PS ≥ 3, long-term oxygen therapy, anemia, diastolic blood pressure < 70 mmHg, Early Warning Score ≥ 3, severe acidosis (pH < 7.20), and serum albumin < 35 g/L. On multivariate analysis, only anemia and WHO-PS ≥ 3 were significant. The presence of both predicted 68% of inpatient deaths, with a specificity of 98%.ConclusionWHO-PS ≥ 3 and anemia are prognostic factors in AHRF with respiratory acidosis due to COPD. A combination of the two provides a simple method of identifying patients unlikely to benefit from NIV.

Post‐intensive care unit respiratory failure in older patients liberated from intensive care unit and ventilator: The predictive value of the National Early Warning Score on intensive care unit discharge

“…In addition to the NEWS, the level of hemoglobin was also found in the present study to be an independent predictor of PIRF‐14. Actually, anemia is associated with the risk of respiratory failure in patients with chronic obstructive pulmonary disease, increased mortality in general ICU patients and increased length of stay in older hospitalized patients . Although the underlying mechanism remains unknown, the present finding might be supported by these reports that anemia is correlated with the risk of PIRF in critical older patients with ICUmv‐lib.…”

Association between hemoglobin and prognosis in patients admitted to hospital for COPD

“…In contrast, a higher prevalence than ours was found in Silverberg et al31 Possible explanations are a different case mix where, for example, diabetes was twice as frequent as in our population and the exclusion from our study of patients admitted previously for AECOPD. In a study of patients treated with noninvasive ventilation for AECOPD, Mydin et al18 found higher prevalence of anemia than in our population. Probably, the inclusion of only patients in need of noninvasive ventilation shifted the case mix with regard to severity of illness compared to our population, which might explain the in-hospital mortality rate of 33% compared to only 7% in our study.…”

Daily Lowest Hemoglobin and Risk of Organ Dysfunctions in Critically Ill Patients

“…Iron deficiency anemia in ventilated COPD patients, and in those with chronic respiratory failure, is known to increase work of breathing and minute ventilation, (30) (31) (32) and transfusion may help to wean these patients from mechanical ventilation (33) (34). There is also a correlation between pulmonary function (Forced expiratory volume, FEV 1 ) and iron status, exacerbated by inflammation and nutritional deficiencies, which many critically ill patients have (35).…”