Increased specimen minimum volume reduces turnaround time and hemolysis

Abstract

Quantity not sufficient (QNS) specimens with minimal blood volume for testing are common in clinical laboratories. However, there is no universal definition of minimum volume for a QNS specimen and little data is available addressing the impact of QNS / low volume specimens on turnaround time (TAT) and sample hemolysis. We compared the TAT and hemolysis index from samples ≤1.0 mL to all specimens received and quantified the number of specimens with reduced blood volume. A new QNS policy requiring ≥1.5 mL of sample in a blood tube for laboratory analysis was implemented and the results were assessed by sample hemolysis and TAT. The median laboratory TAT for samples with ≤1.0 mL of blood was 61 min (Interquartile Range, IQR: 50–82), in contrast to 28 min (26–34) for all samples. The hemolysis index for samples ≤1.0 mL was 112 (65–253) and 15 (8–29) for all samples. Requirement of a minimum volume of 1.5 mL of blood resulted in the proportion of samples with TAT ≥ 60 min to decrease from 10.4% to 4.24% in the ED, and for specimens cancelled due to hemolysis to decrease from 4.24% to 3.38%. This policy was introduced hospital wide with similar effects. Together, we correlate limited specimen volume with an increase in laboratory TAT and hemolysis. Implementation of a QNS policy of ≥1.5 mL and provider education provided a significant and durable reduction in TAT and specimen hemolysis.