Shannon N. Acker

Pediatric specific shock index accurately identifies severely injured children

INTRODUCTION Shock index (SI) (heart rate/systolic blood pressure)>0.9 predicts mortality in adult trauma patients. We hypothesized that age adjusted SI could more accurately predict outcomes in children. METHODS Retrospective review of children age 4-16 years admitted to two trauma centers between 1/07 and 6/13 following blunt trauma with an injury severity score (ISS)>15 was performed. We evaluated the ability of SI>0.9 at emergency department presentation and elevated shock index, pediatric age adjusted (SIPA) to predict outcomes. SIPA was defined by maximum normal HR and minimum normal SBP by age. Cutoffs included SI>1.22 (age 4-6), >1.0 (7-12), and >0.9 (13-16). RESULTS Among 543 children, 50% of children had an SI>0.9 but this fell to 28% using age adjusted SI (SIPA). SIPA demonstrated improved discrimination of severe injury relative to SI: ISS>30: 37% vs 26%; blood transfusion within the first 24 hours: 27% vs 20%; Grade III liver/spleen laceration requiring blood transfusion: 41% vs 26%; and in-hospital mortality: 11% vs 7%. CONCLUSION A pediatric specific shock index (SIPA) more accurately identifies children who are most severely injured, have intraabdominal injury requiring transfusion, and are at highest risk of death when compared to shock index unadjusted for age.

Glasgow motor scale alone is equivalent to Glasgow Coma Scale at identifying children at risk for serious traumatic brain injury.

BACKGROUND Glasgow Coma Scale (GCS) is a validated assessment of neurologic state. Assessment of the eye and verbal components is difficult to reliably obtain in children. We hypothesized that an abnormal Glasgow motor scale (GMS) score alone will reliably identify children with serious traumatic brain injury (TBI). METHODS We reviewed all children with a diagnosis of TBI from 2002 to 2011 at two urban Level I pediatric trauma centers. We used logistic regression to model GCS, GMS, Glasgow verbal scale (GVS), and Glasgow eye scale (GES) for seven outcomes: need for craniotomy, intracranial pressure monitoring, admission to the intensive care unit, hospital stay of 5 days or longer, discharge to rehabilitation, dependence on caretakers at follow-up, and survival to hospital discharge. We then used three measures of fit analysis to determine which scale offered the best fit for each of the outcomes. RESULTS A total of 2,341 patients (mean [SD] age, 6.9 [5.8] years; 64.7% male) with TBI and GCS data available were identified. The median GCS on presentation was 15 (interquartile range [IQR], 8–15); the median GMS on presentation was 6 (IQR, 4–6). The median GVS was 5 (IQR, 1–5), and the median GES was 4 (IQR, 2–4). GCS as a whole offered the best fit for the data in predicting need for intensive care unit admission, need for intracranial pressure monitoring, prolonged hospital length of stay, and discharge to rehabilitation but was equivalent to GMS in predicting need for craniotomy, survival to hospital discharge, or dependence on a caretaker at follow-up. Further analysis revealed that GMS was more predictive of these outcomes than GVS + GES, indicating that GMS provides the greatest contribution to the predictive ability of the GCS. CONCLUSION GMS score alone and GCS do not differ in identifying children with serious TBI. Eliminating the eye and verbal components of GCS does not adversely affect the accuracy of this tool to identify children at risk for serious TBI. LEVEL OF EVIDENCE Prognostic study, level III.

Pulmonary artery endothelial cell dysfunction and decreased populations of highly proliferative endothelial cells in experimental congenital diaphragmatic hernia

Decreased lung vascular growth and pulmonary hypertension contribute to poor outcomes in congenital diaphragmatic hernia (CDH). Mechanisms that impair angiogenesis in CDH are poorly understood. We hypothesize that decreased vessel growth in CDH is caused by pulmonary artery endothelial cell (PAEC) dysfunction with loss of a highly proliferative population of PAECs (HP-PAEC). PAECs were harvested from near-term fetal sheep that underwent surgical disruption of the diaphragm at 60-70 days gestational age. Highly proliferative potential was measured via single cell assay. PAEC function was assessed by assays of growth and tube formation and response to known proangiogenic stimuli, vascular endothelial growth factor (VEGF), and nitric oxide (NO). Western blot analysis was used to measure content of angiogenic proteins, and superoxide production was assessed. By single cell assay, the proportion of HP-PAEC with growth of >1,000 cells was markedly reduced in the CDH PAEC, from 29% (controls) to 1% (CDH) (P < 0.0001). Compared with controls, CDH PAEC growth and tube formation were decreased by 31% (P = 0.012) and 54% (P < 0.001), respectively. VEGF and NO treatments increased CDH PAEC growth and tube formation. VEGF and VEGF-R2 proteins were increased in CDH PAEC; however, eNOS and extracellular superoxide dismutase proteins were decreased by 29 and 88%, respectively. We conclude that surgically induced CDH in fetal sheep causes endothelial dysfunction and marked reduction of the HP-PAEC population. We speculate that this CDH PAEC phenotype contributes to impaired vascular growth in CDH.

Vasopressin Improves Hemodynamic Status in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE To assess the ability of vasopressin to stabilize hemodynamics in infants with systemic hypotension secondary to congenital diaphragmatic hernia (CDH). STUDY DESIGN A retrospective chart review was performed to identify 13 patients with CDH treated with vasopressin for refractory hypotension to assess the effect of vasopressin on pulmonary and systemic hemodynamics and gas exchange in this setting. Data collected included demographics, respiratory support, inotropic agents, pulmonary and systemic hemodynamics, urine output, and serum and urine sodium levels during vasopressin therapy. RESULTS Vasopressin therapy increased mean arterial pressure and decreased pulmonary/systemic pressure ratio, heart rate, and fraction of inspired oxygen. In 6 of 13 patients, extracorporeal membrane oxygenation therapy was no longer indicated after treatment with vasopressin. Improvement in left ventricular function and oxygenation index after vasopressin initiation was associated with a decreased need for extracorporeal membrane oxygenation therapy. Prolonged vasopressin treatment was associated with hyponatremia, increased urine output, and increased urine sodium. CONCLUSIONS Vasopressin stabilized systemic hemodynamics without adverse effects on pulmonary hemodynamics in a subset of infants with CDH. Our results suggest a potential role for vasopressin therapy in patients with CDH with catecholamine-resistant refractory hypotension.

Blood component transfusion increases the risk of death in children with traumatic brain injury.

BACKGROUND Blood transfusion has been associated with worse outcomes in adult trauma patients with traumatic brain injury (TBI). However, the effects in injured children have not been evaluated. We hypothesize that blood transfusion is also associated with worse outcomes in children with TBI. METHODS A retrospective review of the trauma database at two Level I pediatric trauma centers was performed. We reviewed all patients 18 years and younger with TBI, who survived at least 24 hours, from 2002 to 2011. Exclusion criteria include those who underwent craniotomy, thoracotomy, exploratory laparotomy, and any orthopedic procedure. RESULTS A total of 1,607 children with TBI were included in the study population (mean age, 6.4 [5.7] years; 65% male), 178 of whom received a blood transfusion. Mean Injury Severity Score (ISS) was 16.5 (9.1). Patients who received a transfusion had a higher ISS than those who did not (26.7 vs. 15.3). After controlling for age, sex, ISS, Glasgow Coma Scale (GCS) score on presentation, and mechanism of injury, patients who received a blood transfusion were more likely to be admitted to the intensive care unit (p < 0.0001), less likely to survive to hospital discharge (p = 0.02), more likely to be discharged to a rehabilitation facility (p = 0.01) and be dependent on caretakers at follow-up (p < 0.0001), as well as more likely to develop urinary tract infection (p = 0.02) and bacteremia (p = 0.02) during their hospital stay. These differences in outcomes among those who did and did not receive a blood transfusion began to disappear in patients with a nadir hemoglobin of less than 8.0 g/dL. CONCLUSION Pediatric patients sustaining TBI who receive blood transfusion and do not require operative intervention have worse outcomes compared with patients who do not receive transfusion. This includes an increased risk of death. These data suggest that a transfusion trigger of hemoglobin level at 8.0 g/dL in injured children with TBI may be beneficial. LEVEL OF EVIDENCE Epidemiologic study, level III. Therapeutic study, level IV.

Head injury and unclear mechanism of injury: Initial hematocrit less than 30 is predictive of abusive head trauma in young children

PURPOSE Head injury secondary to abusive head trauma (AHT) is a major cause of morbidity and mortality in susceptible young infants and children. Diagnosing AHT remains challenging and is often complicated by a questionable mechanism of injury. Concern of ionizing radiation risk to children undergoing head CT imaging warrants a selective approach. We aimed to evaluate initial findings that could direct further investigation of AHT. METHODS A retrospective review of the trauma databases at a two level one pediatric trauma centers was performed. We reviewed all patients age five years and under with a diagnosis of traumatic brain injury (TBI) from 2002-2011. RESULTS A total of 1129 patients (mean age 1.7 ± 1.7 years; 64% male) with TBI were identified, 429 (38%) of which were the result of AHT. Complete data was available for 921 patients (82%) and were included in statistical evaluation. Forty-eight percent of patients in the AHT group had a hematocrit ≤ 30% on presentation compared to 19% of patients in the non-AHT group. On univariate analysis, a hematocrit of ≤ 30% was predictive of AHT as the cause of injury (P<.0001), as was a platelet count of greater than 400,000 (P<.0001). After controlling for age, sex, ISS, GCS on presentation, need for CPR, and survival to hospital discharge, hematocrit of ≤ 30% and platelets of greater than 400,000 were predictive of AHT as the cause of TBI (P<.05). CONCLUSIONS In the setting of head injury and unclear history of trauma, a hematocrit of ≤ 30% on presentation increases the likelihood of abusive head trauma in children up to the age of 5 years.

Factors associated with peritoneal dialysis catheter complications in children.

BACKGROUND/PURPOSE Peritoneal dialysis (PD) is a common method of renal replacement therapy for children. However, placement of PD catheters has risk, and some are never used. METHODS We conducted a retrospective chart review of children with a PD catheter placed between 2000 and 2014. Logistic regression analyses were used to identify covariates associated with complications. RESULTS We identified 175 children with PD catheters. 110 complications developed in 80 children (45.7%). Complications including unexpected return to the operating room and peritonitis increased as the length of time a catheter was in place increased. Children who weighed <12.4 kg had 3.2 times greater odds of developing a leak (95% CI 1.21-8.63, p=0.02). Twelve children never used their PD catheters, 9 with acute kidney injury (AKI) who recovered from their disease more quickly than expected. No covariate was associated with nonuse. CONCLUSIONS Complications with PD catheters are common and increase the longer catheters are in place. Lower weight children are at greater risk of PD catheter leak. Decreased initial volumes of dialysate in smaller children may mitigate this risk. Nonuse may be reduced if dialysis is permitted the day of placement for children with AKI.

When is it safe to forgo abdominal CT in blunt-injured children?

INTRODUCTION CT is the standard modality to diagnose solid organ injury after blunt trauma; however, the associated radiation carries a risk of cancer. We hypothesized that there are patient-specific factors that can identify those children who require abdominal CT. METHODS We reviewed all children admitted to 2 pediatric trauma centers after blunt trauma with liver or spleen injury from January 2009 to December 2013. The low-risk group was defined as a Glasgow Coma Scale (GCS) of 15 with normal pediatric age-adjusted shock index (heart rate/systolic blood pressure; SIPA) on presentation, and injury attributable to a single, nonmotorized, blunt force to the abdomen. The at-risk group did not meet these criteria. RESULTS We identified 206 children with blunt liver or spleen injury, 101 of whom met the low-risk criteria. Among these 101 children who met the low-risk criteria, there were no deaths, no children required laparotomy, only 1 child required a packed red cell transfusion, and no children required discharge to a rehabilitation facility. CONCLUSION Children who present to the emergency department after blunt abdominal trauma by a nonmotorized force with a normal GCS and SIPA are unlikely to have a solid organ injury that will require intervention.

Preoperative imaging does not predict intrahepatic involvement in choledochal cysts

INTRODUCTION Choledochal cyst (CDC) is a congenital malformation of the bile ducts, which can include the intrahepatic or extrahepatic bile ducts. We hypothesize that preoperative intrahepatic ductal dilation is not predictive of postoperative intrahepatic involvement. METHODS We retrospectively reviewed all cases of CDC in children diagnosed at a single institution between 1991 and 2013. RESULTS Sixty-two patients were diagnosed with CDC during the study period with a median follow-up time of 2.25 (range 0-19.5) years. Forty-two patients (68%) were diagnosed with type I disease preoperatively, and 15 patients (24%) were diagnosed with type IV-A disease. The most common presenting symptoms included pain (34%), jaundice (28%), and pancreatitis (25%). There were no deaths or malignancies and only one postoperative stricture. Forty-two patients (68%) had intrahepatic ductal dilation preoperatively. Only four patients (9%) had intrahepatic ductal dilation following resection (P<0.0001). In one patient, this dilation resolved following stricture revision. Of the four patients with postoperative dilation, two were diagnosed with type I disease, and the other two were diagnosed with type IV-A disease preoperatively. CONCLUSION Preoperative intrahepatic ductal dilation is not predictive of postoperative intrahepatic ductal involvement in children with CDC. The preoperative distinction between type I and IV disease is not helpful in treating these patients.

Altered pulmonary artery endothelial-smooth muscle cell interactions in experimental congenital diaphragmatic hernia

Background:Pulmonary hypertension (PH) secondary to vascular remodeling contributes to poor outcomes in congenital diaphragmatic hernia (CDH), however mechanisms responsible are unknown. We hypothesized that pulmonary artery endothelial cell (PAEC) dysfunction contributes to smooth muscle cell (SMC) hyperplasia in experimental CDH.Methods:PAEC and SMC were isolated from fetal sheep with experimental CDH and controls. SMC growth was assessed alone and with SOD plus catalase and during coculture with control or CDH PAEC with and without ET-1 siRNA transfection. ET-1 protein was measured in PAEC and SMC lysates and supernatant. ROS production was measured in normal and CDH PAECs with and without ET-1 siRNA. PAEC growth and tube formation were measured with SOD plus catalase.Results:CDH SMC growth was decreased and increased with coculture with CDH PAEC more than control PAEC. Treatment of CDH PAEC with SOD plus catalase or ET-1 siRNA prevented the increase in SMC growth seen with coculture. ET-1 protein was increased in CDH PAEC and SMC. ROS production was increased in CDH PAEC and decreased with ET-1 SiRNA. SOD plus catalase restored CDH PAEC growth and tube formation.Conclusion:PAEC dysfunction in experimental CDH increases SMC proliferation via ET-1 induced ROS production by PAEC.