The prognostic value of hypophosphatemia in acute exacerbation of chronic obstructive pulmonary disease (COPD)

Background

Phosphorus (P) is an important electrolyte that plays a significant role in different physiological processes especially muscle contraction and adenosine triphosphate (ATP) high energy bonds. Low phosphorus level in blood may increase the exacerbation of chronic obstructive pulmonary disease (COPD), need, and duration of mechanical ventilation (MV).

Work aim

This study aims to examine and evaluate the effect of low serum phosphorus level on patients admitted with acute exacerbation of COPD regarding the need for ventilation, duration of ventilation and outcome.

Methods

We studied fifty patients with acute exacerbation of COPD admitted to chest department and respiratory ICU at Benha University hospital in the period between October 2014 and March 2015. A comparison was made between the group (A) with low phosphorus (<2.5 mg/dl) and group (B) with normal blood phosphorus (2.5–4.5 mg/dl), serum phosphorus was measured on admission. SIMV mode was the mode of MV in all patients.

Results

Sixty percent of the included patients had low levels of phosphorus while 40% had normal phosphorus level, 25 patients (83.3%) of hypophosphatemic group needed MV and 5 patients (16.7%) didn’t need MV, while in the normal phosphorus group, 11 patients (55%) needed MV and 9 patients (45%) didn’t need MV (P:0.032).

Regarding outcome, 18 patients (60%) with hypophosphatemia were discharged while 12 patients (40%) failed to wean and died. In normal phosphorus group, 14 patients (70%) discharged, but 6 patients (30%) failed to wean and died (P: 0.032), in patients with hypophosphatemia 10 patients had pneumonia with COPD, 5 patients of them needed MV and only one died, in patients with normal phosphorus level 7 patients had pneumonia, only one patient needed MV and died.

Conclusion

Hypophosphatemia may contribute to an increase in the COPD exacerbation, the need for ventilation, the duration of ventilation, and may contribute with other factors in increase in the rate of mortality. Therefore, monitoring and correcting its level is imperative.