Predicting Factors for Requiring Routine Postoperative Blood Analysis in Primary Hip and Knee Arthroplasty: A...

Area of Science:

• Orthopedic Surgery
• Clinical Pathology
• Health Economics

Background:

• Minimizing healthcare expenditure is crucial given high demands on the health sector.
• Routine postoperative blood tests after primary knee and hip arthroplasty represent an area for potential cost savings.
• Developing criteria to identify patients truly needing these tests can reduce unnecessary expenditure.

Purpose of the Study:

• To propose and validate criteria for requesting postoperative blood tests following primary knee and hip arthroplasty.
• To ensure these criteria are safe and do not miss patients requiring essential monitoring.
• To reduce unnecessary blood testing and associated costs in the National Health Service (NHS).

Main Methods:

• Prospective evaluation of 126 patients undergoing elective primary total hip (THR) or total knee replacement (TKR).
• Recording of patient demographics, in-patient events, and hospital readmissions up to 90 days postoperatively.
• Statistical analysis including binary logistic regression to identify predictors for requiring postoperative blood tests.

Main Results:

• Risk factors for requiring postoperative full blood count tests include pre-operative Hb ≤ 110 g/L, cardiac disease, anemia symptoms, and intraoperative blood loss > 500 mL.
• Risk factors for postoperative electrolyte/urea tests include pre-operative electrolyte derangement and clinical signs of renal disturbance.
• No patients required hospital readmission within 90 days.

Conclusions:

• Implementing the devised criteria could have saved 74 blood tests in the cohort of 126 patients.
• The criteria demonstrated a significantly higher odds ratio (14.0) of abnormal results in tested patients compared to those not tested.
• These criteria offer a safe and effective method for reducing unnecessary blood tests and healthcare costs post-arthroplasty.