Discharge Hemoglobin Impacts Functional Recovery After Lumbar Fusion

Retrospective longitudinal observational study.

To identify the impact of anemia at discharge on surgical outcomes and functional recovery following lumbar fusion.

Acute blood loss anemia is common following lumbar spine surgery. Current protocols emphasise limiting transfusions, resulting in more patients being discharged with lower haemoglobin.

Records of a consecutive series of patients who underwent one-level or two-level transforaminal lumbar interbody fusion (TLIF) from 2013 to 2022 were reviewed. Standard demographics, surgical parameters, and complications within a year after discharge were recorded. Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS, 0-10) for back and leg pain were collected preoperatively and at 3 months and 1 year postoperatively. Patients were categorized into three groups based on discharge hemoglobin: moderate (8-10 g/dL), mild (10-13 g/dL for males; 10-12 g/dL for females), and no anemia (>13 g/dL for males; >12 g/dL for females). Complications and PROMs were compared.

Of 576 patients, 253 were included in the analysis. The average hemoglobin at discharge was 11.1±1.6 mg/dL. Fifty-eight patients (23%) were discharged with moderate, 144 (57%) with mild, and 51 (20%) with no anemia. Complications rates were higher in patients discharged with lower hemoglobin, with significant differences observed in 90-day readmission (14%, 4%, 0%, P =0.002), infections (14%, 4%, 4%, P =0.022), stroke (5%, 0%, 2%, P =0.021), and gastrointestinal complications (13%, 0%, 8%, P <0.001). Patients with moderate anemia at discharge showed the highest ODI and NRS score of leg pain at all timepoints. There were significant differences in the trajectories of ODI ( P =0.021) and leg pain ( P =0.018) among the three groups. Among 180 patients with no complications, either during hospitalization or after discharge, the significant differences remained in leg pain.

Anaemia at discharge was significantly associated with the complication rate and worse functional recovery following lumbar fusion surgery.