Assessment of phosphatemia at admission to the intensive care unit to predict mechanical ventilation among patients with acute exacerbation of chronic obstructive pulmonary disease: a retrospective cohort study.

Abstract

Hypophosphatemia has been reported to impair diaphragmatic function in patients with chronic obstructive pulmonary disease (COPD). However, little is known about the role of dysphosphatemia at admission [plasmatic phosphate concentration at intensive care unit (ICU) admission (T0-Ph)] to the ICU and respiratory outcomes among patients with severe acute COPD exacerbation. We aimed to assess the value of T0-Ph as a predictive factor of invasive mechanical ventilation (MV) during ICU stay. We retrospectively included consecutive patients admitted to the ICU for a severe acute exacerbation of COPD between May 2015 and December 2018. Logistic multivariate regression analysis was performed to identify association between T0-Ph and the need for invasive MV during the ICU stay. We included 198 patients of whom 132 (67%) were male. The median age was 70 [interquartile range (IQR), 61-77] years. Nine (4.5%) patients died in the ICU. Median T0-Ph was significantly higher among patients requiring invasive MV as compared to non-intubated patients [1.23 (IQR, 1.07-1.41) and 1.09 (IQR, 0.91-1.27) mmol/L; P=0.005]. By multivariate analysis, pneumonia [odds ratio (OR) =6.42; 95% confidence interval (CI): 2.78-15.96; P<0.0001) and a history of intubation (OR =3.33; 95% CI: 0.97-11.19; P=0.05) were independently associated with the need for invasive MV, whereas T0-Ph was not (OR =1.75; 95% CI: 0.72-4.44; P=0.22). T0-Ph was significantly higher in patients requiring invasive MV. However, T0-Ph was not associated with the need for invasive MV in multivariate analysis.