Association between intravenous iron therapy and short-term mortality risk in older patients undergoing hip fracture surgery: an observational study

BACKGROUND: Anemia is common among ortho-geriatric hip fracture patients and is associated with prolonged recovery and increased postoperative mortality rate. Intravenous iron seems to increase hemoglobin recovery and reduce the mortality rate in patients undergoing orthopedic surgeries. This study investigated the association between short-term mortality risk and intravenous iron therapy in older patients undergoing hip fracture surgery. METHODS: This observational study included 210 patients undergoing hip fracture surgery from July 2018 to May 2020. These 210 patients were alive and had a hemoglobin ≤ 6.5 mmol/L on the 3rd postoperative day. In May 2019, a local intravenous iron therapy protocol was implemented and recommended intravenous iron (Monofer©) if hemoglobin on the 3rd postoperative day was ≤ 6.5 mmol/L. According to the treatment of postoperative anemia between the 1st and 3rd day post-surgery, the patients were divided into four groups: no treatment (n=52), blood transfusion (n=38), IV Monofer (n=80), and blood transfusion and IV Monofer (n=40). Primary outcome was 30-day mortality post-surgery. The secondary outcome was the impact on hemoglobin level 14–30 days postoperatively. Multivariable Cox regression was used to estimate the 30-day mortality standardized for covariates. RESULTS: Of 210 patients, 17 (8.1%) died within 30 days after surgery. There was a significantly lower mortality among the patients who received IV Monofer compared to those who received no treatment (HR 0.17, 95% CI [0.03–0.93], P = 0.041). Among the 86 patients with available hemoglobin measurements within 14 to 30 days post-surgery, there was no significant difference in hemoglobin level between the various treatment groups (mean 6.6 mmol/L, P = 0.1165). CONCLUSION: IV Monofer on the 3rd postoperative day in older hip fracture patients seemed to reduce 30-day mortality compared with no treatment. No significant differences in hemoglobin levels between 14 and 30 days post-surgery across treatment groups were found, although this was assessed in a subset of patients with available hemoglobin levels warranting further study. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13018-021-02462-x.