Utility of Routine Laboratory Testing for Detecting Intra-abdominal Injury in the Pediatric Trauma Patient

Abstract

Objective. To assess the prevalence of laboratory abnormalities (complete blood cell count, electrolytes, blood urea nitrogen, creatinine, glucose, aspartate aminotransferase, alanine aminotransferase, amylase, lipase, urinalysis [U/A]) and the sensitivity and specificity of the physical examination (PE) and screening laboratory tests for identifying intra-abdominal injury (IAI) in moderately injured pediatric patients. Design, participants, and setting. Phase I: Retrospective review of 285 consecutive level II (moderately injured) trauma patients seen at a children's hospital emergency department/pediatric trauma center. All patients were received directly from the scene and had the following data recorded: mechanism of injury, Glasgow coma score, trauma score, pediatric trauma score, systematically recorded PE findings, laboratory results, and injuries detected during hospitalization. Phase II: To confirm the sensitivity of the PE and U/A found in phase I, the model was applied to 91 additional trauma patients identified by International Classification of Diseases, 9th revision (ICD-9) codes as having IAI. Intervention. None. Results. Phase I: A total of 3939 tests were ordered for the 285 patients entered in phase I. Aspartate aminotransferase and alanine aminotransferase values were obtained in 59% of patients; glucose level was obtained in 78% of patients; complete blood cell count, U/A, and levels of electrolytes, blood urea nitrogen, creatinine, amylase, and lipase were obtained in more than 85% of patients. The overall prevalence of laboratory abnormalities was 5.7%. Fourteen patients (4.8%) were identified who had a total of 23 significant IAIs (9 pancreatic, 6 splenic, 5 renal, 3 hepatic). The PE combined with U/A showing more than five red blood cells per high-power field had a sensitivity of 100%, specificity of 64%, positive predictive value of 13%, and negative predictive value of 100% for the detection of IAI. The presence of laboratory abnormalities suggesting injury did not increase the sensitivity of the model and significantly decreased both specificity and positive predictive value. Phase II: The PE combined with U/A identified an abnormality in 89 (97.8%) of 91 cases (95% confidence interval = 94.8% to 100%). Conclusions. In the moderately injured pediatric trauma patient, (1) there is a low prevalence of laboratory abnormalities; (2) the PE combined with U/A is a highly sensitive screen for IAI; and (3) in patients with a normal PE of the abdomen and a normal U/A, laboratory testing seldom identifies unsuspected IAI.

Screening Laboratory Testing in Asymptomatic Minor Pediatric Blunt Trauma Leads to Unnecessary Needle Sticks

“…Although there is extensive research about the benefits of laboratory testing in pediatric trauma, most of these studies included patients with hemodynamic instability, abdominal pain, and other major injuries. 3,15,18 Studies have shown that patients with either a positive abdominal examination result 3,25 or an abnormal UA result had a high risk of intra-abdominal injury with a sensitivity of 100%. 15 Again, Holmes et al 3 proposed that 6 factors could predict intra-abdominal injury; GCS <14, elevated transaminases, positive UA (>5 rbc/hpf), abdominal tenderness, hematocrit <30%, and femur fracture.…”

“…3,15,18 Studies have shown that patients with either a positive abdominal examination result 3,25 or an abnormal UA result had a high risk of intra-abdominal injury with a sensitivity of 100%. 15 Again, Holmes et al 3 proposed that 6 factors could predict intra-abdominal injury; GCS <14, elevated transaminases, positive UA (>5 rbc/hpf), abdominal tenderness, hematocrit <30%, and femur fracture. Using these 6 factors, they could identify 98% of the patients with intra-abdominal injury.…”

“…Threshold values for abnormally high values for CBC, CMP, liver function tests, and coagulation profile were based on trauma literature. 15,[21][22][23] Univariate descriptive analysis of data was performed using IBM SPSS Statistics version 24 (IBM Corp, Armonk, NY).…”

“…[12][13][14] Screening laboratory tests have typically been used to identify significant blood loss, solid organ injury, or metabolic derangements in the trauma setting. [15][16][17] Current clinical prediction tools use screening laboratory tests, in combination with physical examination, urinalysis (UA), mechanism of trauma, and other injuries to stratify patients with intra-abdominal injuries. These studies have evaluated patients with significant mechanisms of injury, multiple injuries, altered mental status, and hemodynamic instability.…”

“…These studies have evaluated patients with significant mechanisms of injury, multiple injuries, altered mental status, and hemodynamic instability. 3,15,18 However, only 2 studies have tried to determine the utility of blood work in asymptomatic patients with minor trauma that still undergo screening laboratory work. 3,6 Screening blood work requires a needle stick, which is a prevalent type of procedural pain.…”