Objective: To explore the prognostic effects of anemia among the mechanically ventilated patients.
Methods: A prospective observational study was undertaken in a 12-bed intensive care unit (ICU). Patients requiring mechanical ventilation for at least 72 hours and hemoglobin (Hb)≥100 g/L were enrolled. Serum erythropoietin (EPO), Fe(3+), transferrin (TRF) levels were measured as baseline when they were enrolled and were repeated at day 3, 7 and 14. According to Hb concentration at day 3, patients were divided into anemia group (defined as Hb<100 g/L) and non-anemia group. Serum EPO, Fe(3+), TRF at day 1, 3 and 7, and mean amount of blood transfusion within 14 days, mean volume of blood drawn daily in 3, 7 and 14 days, the survival rate with unassisted breathing at day 28, ICU mortality, length of ICU stay, ventilator days, length of hospital stay and 28-day mortality were compared.
Results: Forty mechanically ventilated patients were enrolled and divided into anemia group (n = 18) and non-anemia group (n = 22). It was shown that the anemia group had lower serum Fe(3+) concentration, and higher serum EPO and TRF. The anemia group also had more transfusion [U: 4.0 (2.0, 6.0) vs. 2.0 (0.0, 2.0), P < 0.01], longer length of hospital stay [days: 35.0 (16.5, 51.6) vs. 24.5 (10.0, 35.8), P < 0.05], decreased rate of survival with unassisted breathing at day 28 (44.4% vs. 72.7%, P < 0.05) and higher ICU mortality (44.4% vs. 13.6%, P < 0.05). But there were no significant differences between anemia group and control group in mechanical ventilated days (days: 18.3 ± 10.8 vs. 11.6 ± 8.2, P > 0.05), length of ICU stay [days: 16.5 (8.0, 21.5) vs. 11.0 (5.8, 18.3),P > 0.05] and hospital mortality (61.1% vs. 31.8%, P > 0.05).
Conclusion: The anemic patients had longer ventilator days, hospital stay, higher ICU mortality, and lower rate of survival with unassisted breathing at day 28.