Photo by Elise Amendola
A young trauma patient’s hematocrit level at hospital admission may predict the need for transfusion, new research suggests.
Results of this retrospective, single-center study indicate that children and adolescents with a hematocrit level of 35% or less at admission are more likely than their peers with higher hematocrit levels to require a transfusion after trauma.
The study was published in the Journal of Trauma and Acute Care Surgery.
“A quick and cost-effective measure, such as admission hematocrit, to identify pediatric patients who are at a high risk for bleeding could provide a critical improvement in optimizing care for children, while reducing costs,” said study author Christopher P. Gayer, MD, PhD, of Children's Hospital Los Angeles (CHLA) in California.
For this research, Dr Gayer and his colleagues examined the medical records of all patients, ages 0 to 17, who presented to the level 1 pediatric trauma center at CHLA between 2005 and 2013.
Of all the patients, 1341 had hematocrit measured at admission. The researchers divided this group into patients who required an intervention—transfusion or operation—for their bleeding (n=93) and those who did not (n=1248).
The mean hematocrit was 38.0 for patients who did not require an intervention and 34.3 for those who did (P<0.01). The mean hematocrit was 26.9 in patients who required a transfusion secondary to bleeding and 36.0 in those who required an operative intervention for nonhemostatic indications (P<0.01).
The researchers then analyzed a subset of patients who had an abdominal CT scan, as these patients had a definitive presence or absence of intra-abdominal injury. There was a significant decrease in admission hematocrit between patients who required a transfusion for an intra-abdominal injury and those who did not—29% and 37%, respectively (P<0.01).
Serial hematocrit values remained significantly lower in the patients who required a transfusion up to 67 hours after admission (P=0.04). The researchers said this suggests that hematocrit is a valuable predictor for requiring a transfusion at least 2 days after an injury, and it may be useful for patients presenting well after their initial injury.
The team then evaluated whether an admission hematocrit cutoff of 35% or less could predict the need for transfusion. For all patients, a cutoff of 35% or less had a sensitivity of 94%, specificity of 77%, positive-predictive value of 5%, and negative predictive value of 99.9%.
In patients who had an abdominal CT, a cutoff hematocrit of 35% or less had a sensitivity of 90%, specificity of 76%, positive predictive value of 21%, and negative predictive value of 99%.
These results led the researchers to conclude that this hematocrit cutoff may be a reliable screening tool.
“Admission hematocrit can be done rapidly in the trauma bay, is relatively inexpensive, causes minimal harm, and can aid in critical decision-making and rapid identification of occult bleeding,” said study author Jamie Golden, MD, of CHLA.
“Our results show that a hematocrit level of less than 35% on admission predicts a greater likelihood for the need of transfusion in pediatric blunt trauma patients.”
The researchers stressed that a doctor's concern in the face of clinical signs of hemorrhagic shock should always take priority over lab data. However, a repeat hematocrit can be quickly and easily performed if clinically indicated.
They added that the results of their study require validation in a prospective, multicenter study.
