Medicina (Kaunas). 2026 Oct 17;62(10):2009. doi: 10.3390/medicina62102009.
ABSTRACT
Background and Objectives: Hemolysis is the most common preanalytical error in emergency department samples and can compromise diagnostic reliability. Evidence on tourniquet-release timing under standardized pressure is limited. We assessed whether initiating cuff deflation when blood enters the first tube and completing it as that tube fills reduces hemolysis. Materials and Methods: In a single-center, parallel-group, 1:1 randomized trial (ClinicalTrials.gov NCT07617103), 792 adults triaged as Emergency Severity Index (ESI) 3 to 5 underwent venipuncture with stasis applied at 60 mm Hg by sphygmomanometer. Cuff deflation was initiated when blood entered the first tube and completed as that tube filled (n = 396) or after the last tube filled (n = 396). The primary outcome was the proportion of serum separator gel tubes with a hemolysis index of 1+ or greater, assessed by personnel blinded to allocation. The primary complete-case analysis included 790 participants analyzed as randomized. Results: Hemolysis occurred in 68 of 395 patients (17.2%) with early release and 103 of 395 (26.1%) with late release (absolute risk reduction 8.9 percentage points; 95% confidence interval (CI), 3.1-14.5; p = 0.003; number needed to treat (NNT) 11.3). The adjusted odds ratio in the prespecified model was 0.58 (95% CI, 0.41-0.82), and the ordinal distribution also favored early release (p = 0.002). No early-release patient exceeded 60 s of stasis, versus 29.0% with late release. Complication estimates were imprecise (8.1% vs. 5.6%; risk difference +2.5 points; 95% CI, -1.0 to 6.1). Conclusions: In adult emergency department patients presenting with non-critical acuity (ESI 3-5) undergoing direct 21-gauge venipuncture under standardized 60 mm Hg cuff pressure, early cuff release significantly reduced specimen hemolysis (NNT 11.3 for preventing one laboratory-defined hemolyzed sample). These findings cannot be generalized to resuscitated patients (ESI 1-2), intravenous catheter blood draws, winged collection devices, or uncalibrated elastic tourniquets.
PMID:42942540 | DOI:10.3390/medicina62102009
