The Use of Biomarkers in the Early Diagnosis of Septic Arthritis and Osteomyelitis-A Pilot Study

BACKGROUND

The diagnosis of septic arthritis (SA) and osteomyelitis (OM) has remained challenging in the pediatric population, often accompanied by delays and requiring invasive interventions. The purpose of this pilot study is to identify a novel panel of biomarkers and cytokines that can accurately differentiate SA and OM at initial presentation using serum alone.

METHODS

Twenty patients below 18 years old whose working diagnosis included SA (n=10) and OM (n=10) were identified. Serum was collected at initial evaluation. Each sample underwent seven ELISA [C1-C2, COMP, CS-846, hyaluronan, procalcitonin, PIIANP, C-terminal telopeptide of type II collagen (CTX-II)] and 65-plex cytokine panels. Principal component and Lasso regression analysis were performed to identify a limited set of predictive biomarkers.

RESULTS

Mean age was 4.7 and 9.5 years in SA and OM patients, respectively (P=0.029). 50% of SA patients presented within 24 hours of symptom onset, compared with 0% of OM patients (P=0.033). 30% of SA patients were discharged home with an incorrect diagnosis and re-presented to the emergency department days later. At time of presentation: temperature ≥38.5°C was present in 10% of SA and 40% of OM patients (P=0.12), mean erythrocyte sedimentation rate (mm/h) was 51.6 in SA and 44.9 in OM patients (P=0.63), mean C-reactive protein (mg/dL) was 55.8 in SA and 71.8 in OM patients (P=0.53), and mean white blood cells (K/mm3) was 12.5 in SA and 10.4 in OM patients (P=0.34). 90% of SA patients presented with ≤2 of the Kocher criteria. 100% of SA and 40% of OM patients underwent surgery. 70% of SA cultures were culture negative, 10% MSSA, 10% Kingella, and 10% Strep pyogenes. 40% of OM cultures were culture negative, 50% MSSA, and 10% MRSA. Four biomarkers [CTx-II, transforming growth factor alpha (TGF-α), monocyte chemoattractant protein 1 (MCP-1), B cell-attracting chemokine 1] were identified that were able to classify and differentiate 18 of the 20 SA and OM cases correctly, with 90% sensitivity and 80% specificity.

CONCLUSIONS

This pilot study identifies a panel of biomarkers that can differentiate between SA and OM at initial presentation using serum alone.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Use of a Sterile Collection Process to Reduce Contaminated Peripheral Blood Cultures

BACKGROUND

Contaminated blood cultures pose a significant burden by subjecting children to unnecessary testing, procedures, and antibiotics and increasing health care costs. The aim of our quality improvement (QI) initiative was to decrease the percentage of contaminated peripheral blood cultures in our pediatric emergency department (ED) from an average of 6.7% to <3% over a 16-month period.

METHODS

The QI initiative was implemented in the pediatric ED of a tertiary care children's hospital. Interventions included change of the peripheral blood culture collection from a clean to a sterile process, nursing education, and individualized feedback. The primary outcome measure was the percentage of contaminated peripheral blood cultures. The process measure was the percentage of nurses who completed 75% to 100% of the steps of the sterile collection process, as measured by self-reporting in audit cards. The balancing measures were time from antibiotic ordering to time of administration and ED length of stay.

RESULTS

We decreased the percentage of contaminated peripheral blood cultures threefold from a baseline (June 2, 2018, to December 31, 2018) of 6.7% to 2.1% during the intervention period (January 1, 2019, to April 30, 2020). Ninety-eight percent of nurses who completed audit cards reported performing 75% to 100% of the steps of the new sterile process. There was no significant difference in the average time from antibiotic ordering to antibiotic administration or ED length of stay between the baseline and intervention periods.

CONCLUSIONS

Use of a sterile blood culture collection process, in addition to nursing education and individualized feedback, is an effective method to decrease peripheral blood culture contamination rates in a pediatric ED.

Implementation of Telemedicine in Pediatric and Neonatal Transport

OBJECTIVE

Telemedicine uses video technology to communicate visual clinical information. This study aimed to implement telemedicine in pediatric and neonatal transport, assess its value, and identify barriers.

METHODS

This prospective study implemented telemedicine before transport to a tertiary care children's hospital. A preimplementation survey assessed attitudes toward telemedicine and perceived barriers. During the 12-week pilot, a video connection was initiated between transport and medical control. We collected survey results measuring telemedicine usefulness and hindrance after each use. A postimplementation survey assessed opinions about when telemedicine was useful.

RESULTS

Initially, 82% of users had no direct experience with telemedicine. Perceived utility and burden of telemedicine varied significantly by department. During the study, telemedicine was offered 65% of the time, initiated in 47% of cases, and successful in 30% of cases. The greatest barrier was connectivity. Over time, transport members and physicians found telemedicine to be significantly more useful. In 14 cases, telemedicine changed patient outcome or management. Providers who reported a change in management rated telemedicine as significantly more useful.

CONCLUSION

This prospective pilot successfully implemented telemedicine before pediatric transport. Telemedicine was more useful in patients with visual findings on examination and, in some cases, changed the clinical outcome.

Circulating matrix metalloproteinases in children with diabetic ketoacidosis

BACKGROUND AND OBJECTIVE

Matrix metalloproteinases (MMPs) mediate blood-brain barrier dysfunction in inflammatory disease states. Our objective was to compare circulating MMPs in children with diabetic ketoacidosis (DKA) to children with type 1 diabetes mellitus without DKA.

RESEARCH DESIGN AND METHODS

This was a prospective study performed at five tertiary-care pediatric hospitals. We measured plasma MMP-2, MMP-3, and MMP-9 early during DKA (time 1; within 2 h of beginning intravenous fluids) and during therapy (time 2; median 8 h; range: 4-16 h). The primary outcome was MMP levels in 34 children with DKA vs. 23 children with type 1 diabetes without DKA. Secondary outcomes included correlations between MMPs and measures of DKA severity.

RESULTS

In children with DKA compared with diabetes controls, circulating MMP-2 levels were lower (mean 77 vs. 244 ng/mL, p < 0.001), MMP-3 levels were similar (mean 5 vs. 4 ng/mL, p = 0.57), and MMP-9 levels were higher (mean 67 vs. 25 ng/mL, p = 0.002) early in DKA treatment. MMP-2 levels were correlated with pH at time 1 (r = 0.45, p = 0.018) and time 2 (r = 0.47, p = 0.015) and with initial serum bicarbonate at time 2 (r = 0.5, p = 0.008). MMP-9 levels correlated with hemoglobin A1c in DKA and diabetes controls, but remained significantly elevated in DKA after controlling for hemoglobin A1c (β = -31.3, p = 0.04).

CONCLUSIONS

Circulating MMP-2 levels are lower and MMP-9 levels are higher in children during DKA compared with levels in children with diabetes without DKA. Alterations in MMP expression could mediate BBB dysfunction occurring during DKA.

Challenges Enrolling Children Into Traumatic Brain Injury Trials: An Observational Study

OBJECTIVES

In preparation for a clinical trial of therapeutic agents for children with moderate-to-severe blunt traumatic brain injuries (TBIs) in emergency departments (EDs), we conducted this feasibility study to (1) determine the number and clinical characteristics of eligible children, (2) determine the timing of patient and guardian arrival to the ED, and (3) describe the heterogeneity of TBIs on computed tomography (CT) scans.

METHODS

We conducted a prospective observational study at 16 EDs of children ≤ 18 years of age presenting with blunt head trauma and Glasgow Coma Scale scores of 3-12. We documented the number of potentially eligible patients, timing of patient and guardian arrival, patient demographics and clinical characteristics, severity of injuries, and cranial CT findings.

RESULTS

We enrolled 295 eligible children at the 16 sites over 6 consecutive months. Cardiac arrest and nonsurvivable injuries were the most common characteristics that would exclude patients from a future trial. Most children arrived within 2 hours of injury, but most guardians did not arrive until 2-3 hours after the injury. There was a substantial range in types of TBIs, with subdural hemorrhages being the most common.

CONCLUSION

Enrolling children with moderate-to-severe TBI into time-sensitive clinical trials will require large numbers of sites and meticulous preparation and coordination and will prove challenging to obtain informed consent given the timing of patient and guardian arrival. The Federal Exception from Informed Consent for Emergency Research will be an important consideration for enrolling these children.

Relationship of Physician-identified Patient Race and Ethnicity to Use of Computed Tomography in Pediatric Blunt Torso Trauma

OBJECTIVES

The objective was to determine whether a child's race or ethnicity as determined by the treating physician is independently associated with receiving abdominal computed tomography (CT) after blunt torso trauma.

METHODS

We performed a planned secondary analysis of a prospective observational cohort of children < 18 years old presenting within 24 hours of blunt torso trauma to 20 North American emergency departments (EDs) participating in a pediatric research network, 2007-2010. Treating physicians documented race/ethnicity as white non-Hispanic, black non-Hispanic, or Hispanic. Using a previously derived clinical prediction rule, we classified each child's risk for having an intra-abdominal injury undergoing acute intervention to define injury severity. We performed multivariable analyses using generalized estimating equations to control for confounding and for clustering of children within hospitals.

RESULTS

Among 12,044 enrolled patients, treating physicians documented race/ethnicity as white non-Hispanic (n = 5,847, 54.0%), black non-Hispanic (n = 3,687, 34.1%), or Hispanic of any race (n = 1,291, 11.9%). Overall, 51.8% of white non-Hispanic, 32.7% of black non-Hispanic, and 44.2% of Hispanic children underwent abdominal CT imaging. After age, sex, abdominal ultrasound use, risk for intra-abdominal injury undergoing acute intervention, and hospital clustering were adjusted for, the likelihood of receiving an abdominal CT was lower (odds ratio [OR] = 0.8, 95% confidence interval [CI] = 0.7 to 0.9) for black non-Hispanic than for white non-Hispanic children. For Hispanic children, the likelihood of receiving an abdominal CT did not differ from that observed in white non-Hispanic children (OR = 0.9, 95% CI = 0.8 to 1.1).

CONCLUSIONS

After blunt torso trauma, pediatric patients identified by the treating physicians as black non-Hispanic were less likely to receive abdominal CT imaging than those identified as white non-Hispanic. This suggests that nonclinical factors influence clinician decision-making regarding use of abdominal CT in children. Further studies should focus on explaining how patient race can affect provider choices regarding ED radiographic imaging.

Incidental findings in children with blunt head trauma evaluated with cranial CT scans

OBJECTIVE

Cranial computed tomography (CT) scans are frequently obtained in the evaluation of blunt head trauma in children. These scans may detect unexpected incidental findings. The objectives of this study were to determine the prevalence and significance of incidental findings on cranial CT scans in children evaluated for blunt head trauma.

METHODS

This was a secondary analysis of a multicenter study of pediatric blunt head trauma. Patients <18 years of age with blunt head trauma were eligible, with those undergoing cranial CT scan included in this substudy. Patients with coagulopathies, ventricular shunts, known previous brain surgery or abnormalities were excluded. We abstracted radiology reports for nontraumatic findings. We reviewed and categorized findings by their clinical urgency.

RESULTS

Of the 43,904 head-injured children enrolled in the parent study, 15,831 underwent CT scans, and these latter patients serve as the study cohort. On 670 of these scans, nontraumatic findings were identified, with 16 excluded due to previously known abnormalities or surgeries. The remaining 654 represent a 4% prevalence of incidental findings. Of these, 195 (30%), representing 1% of the overall sample, warranted immediate intervention or outpatient follow-up.

CONCLUSIONS

A small but important number of children evaluated with CT scans after blunt head trauma had incidental findings. Physicians who order cranial CTs must be prepared to interpret incidental findings, communicate with families, and ensure appropriate follow-up. There are ethical implications and potential health impacts of informing patients about incidental findings.

Factors associated with adverse outcomes in children with diabetic ketoacidosis-related cerebral edema

OBJECTIVE

To investigate the relation between outcomes of children with diabetic ketoacidosis (DKA)-related cerebral edema and baseline clinical features and therapeutic interventions for treatment of cerebral edema.

STUDY DESIGN

All children </=18 years old with DKA and cerebral edema (n = 61) were retrospectively identified from 10 pediatric centers between 1982 and 1997. Demographic, biochemical, and therapeutic data were collected. Ordinal logistic regression analysis was used to identify factors associated with the clinical outcome (death or persistent vegetative state; mild to moderate neurological disability; or normal) after adjusting for known risk factors for the development of cerebral edema as well as the degree of neurologic depression at the time of diagnosis of cerebral edema.

RESULTS

Seventeen (28%) children died or survived in a vegetative state; 8 (13%) survived with mild to moderate neurologic disabilities; and 36 (59%) survived without sequelae. Factors associated with poor outcomes included greater neurologic depression at the time of diagnosis of cerebral edema, a high initial serum urea nitrogen concentration, and intubation with hyperventilation to a PCO (2) <22 mm Hg.

CONCLUSIONS

After adjusting for potential confounding variables and the degree of neurologic compromise at the initiation of therapy, intubation with hyperventilation is associated with adverse outcomes of DKA-related cerebral edema. Greater neurologic depression at the time of diagnosis of cerebral edema and a higher initial serum urea nitrogen concentration are also associated with poor outcome.

Risk factors for cerebral edema in children with diabetic ketoacidosis. The Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics

BACKGROUND

Cerebral edema is an uncommon but devastating complication of diabetic ketoacidosis in children. Risk factors for this complication have not been clearly defined.

METHODS

In this multicenter study, we identified 61 children who had been hospitalized for diabetic ketoacidosis within a 15-year period and in whom cerebral edema had developed. Two additional groups of children with diabetic ketoacidosis but without cerebral edema were also identified: 181 randomly selected children and 174 children matched to those in the cerebral-edema group with respect to age at presentation, onset of diabetes (established vs. newly diagnosed disease), initial serum glucose concentration, and initial venous pH. Using logistic regression we compared the three groups with respect to demographic characteristics and biochemical variables at presentation and compared the matched groups with respect to therapeutic interventions and changes in biochemical values during treatment.

RESULTS

A comparison of the children in the cerebral-edema group with those in the random control group showed that cerebral edema was significantly associated with lower initial partial pressures of arterial carbon dioxide (relative risk of cerebral edema for each decrease of 7.8 mm Hg [representing 1 SD], 3.4; 95 percent confidence interval, 1.9 to 6.3; P<0.001) and higher initial serum urea nitrogen concentrations (relative risk of cerebral edema for each increase of 9 mg per deciliter [3.2 mmol per liter] [representing 1 SD], 1.7; 95 percent confidence interval, 1.2 to 2.5; P=0.003). A comparison of the children with cerebral edema with those in the matched control group also showed that cerebral edema was associated with lower partial pressures of arterial carbon dioxide and higher serum urea nitrogen concentrations. Of the therapeutic variables, only treatment with bicarbonate was associated with cerebral edema, after adjustment for other covariates (relative risk, 4.2; 95 percent confidence interval, 1.5 to 12.1; P=0.008).

CONCLUSIONS

Children with diabetic ketoacidosis who have low partial pressures of arterial carbon dioxide and high serum urea nitrogen concentrations at presentation and who are treated with bicarbonate are at increased risk for cerebral edema.

A rapid method for the analysis of influenza virus genes: application to the reassortment of equine influenza virus genes

We describe a rapid method for genetic characterisation of influenza virus genes using reverse transcription and amplification by polymerase chain reaction (RT/PCR) of all virus segments simultaneously (multiplex RT/PCR) using primers based on the conserved terminal sequences. The product has been shown to be suitable for determination of partial nucleotide sequences which can be used to search nucleotide sequence databases and rapidly map the genetic origin of each segment. We illustrate the use of the method by analysing genetic reassortment in H7N7 equine influenza viruses.