Preoperative Dehydration Is an Underrecognized Modifiable Risk Factor in Total Hip Arthroplasty

Dehydration is an overlooked modifiable risk factor that should be optimized prior to elective total hip arthroplasty (THA) to reduce postoperative complications and inpatient costs. All primary THA from 2005 – 2019 were queried from the National Surgical Quality Improvement Program database, and patients were compared based on dehydration status: blood urea nitrogen (BUN): creatinine ratio (Cr) (BUN/Cr) < 20 (nondehydrated), 20 ≤ BUN/Cr ≤ 25 (moderately dehydrated), 25 < BUN/ Cr (severely dehydrated). A subgroup analysis involving only elderly patients > 65 years and normalized gender-adjusted Cr values was also performed. The analysis included 212,452 patients who underwent THA. Adjusted multivariate logistic regression analysis showed that the severely dehydrated cohort had a greater risk of overall complications, postoperative anemia requiring transfusion, nonhome discharge, and increased length of stay (all p < 0.01). Among the elderly, dehydrated patients had a greater risk of postoperative transfusion, cardiac complications, and nonhome discharge (all p < 0.01). BUN/Cr > 20 is an important preoperative diagnostic tool to identify at-risk dehydrated patients. Providers should optimize dehydration to prevent complications, decrease costs, and improve discharge planning. (Journal of Surgical Orthopaedic Advances 33(1):017-025, 2024)

Key words: hip arthroplasty, postoperative complications, dehydration status, BUN/Cr ratio, ACS NSQIP