Abstract
Introduction: Total hip-joint arthroplasty is associated with a high rate of peri-operative blood transfusion, which has associated risk. Previous studies have identified individual factors than can predict those patients most at risk of post-operative allogenic blood transfusion. We undertook this study to attempt to identify further factors that may predict post-operative blood transfusion.
Methods: Data was collected pre-operatively for patient demographics including type of surgery, sex, age, BMI, ASA, pre-operative haemoglobin & pre-operative packed cell volume for all total hip arthroplasties performed by a single surgeon over twelve months (Total number 233; 166 primaries, 33 resurfacing & 20 revision arthroplasties: 14 excluded for insufficient data). Post-operative data collection included post-operative haemoglobin levels and allogenic transfusion requirements.
Results: Of 166 patients who underwent primary hip arthroplasty, 25 (15.1%) received allogenic blood transfusions, an average volume of 2.1 units per patient transfused. Analysis revealed significant predictive factors of gender (females > males, p=0.0019), advancing age (p=0.0045), lower height (p< 0.0000), lower pre-operative weight (p=0.0010), lower pre-operative haemoglobin (p< 0.0000), and lower pre-operative packed cell volume (p< 0.0000). Patients who underwent revision surgery were also more likely to have undergone transfusion compared to both primary (6.1% transfused, p=0.025) and resurfacing arthroplasty (35% transfused, p=0.009). BMI and ASA were found to not be significant risk factors. Pre-operative packed cell volume (PCV) showed the strongest correlation with post-operative blood transfusion. Cases with a PCV below the average of 39% had a rate of transfusion of 28%, 6.4 times greater than for those patients above the average at 4.4% (p< 0.0000).
Discussion: Pre-operative measurements of height, weight, haemoglobin and packed cell volume, together with factors including sex & type of surgery can identify those patients who are at greater risk of post-operative transfusion allowing selective transfusion prevention strategies.
Correspondence should be addressed to Mr Peter Howard, Editorial Secretary, BHS, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE, England.
