Stephen Blumberg

Identifying Children at Very Low Risk of Clinically Important Blunt Abdominal Injuries

STUDY OBJECTIVE We derive a prediction rule to identify children at very low risk for intra-abdominal injuries undergoing acute intervention and for whom computed tomography (CT) could be obviated. METHODS We prospectively enrolled children with blunt torso trauma in 20 emergency departments. We used binary recursive partitioning to create a prediction rule to identify children at very low risk of intra-abdominal injuries undergoing acute intervention (therapeutic laparotomy, angiographic embolization, blood transfusion for abdominal hemorrhage, or intravenous fluid for ≥2 nights for pancreatic/gastrointestinal injuries). We considered only historical and physical examination variables with acceptable interrater reliability. RESULTS We enrolled 12,044 children with a median age of 11.1 years (interquartile range 5.8, 15.1 years). Of the 761 (6.3%) children with intra-abdominal injuries, 203 (26.7%) received acute interventions. The prediction rule consisted of (in descending order of importance) no evidence of abdominal wall trauma or seat belt sign, Glasgow Coma Scale score greater than 13, no abdominal tenderness, no evidence of thoracic wall trauma, no complaints of abdominal pain, no decreased breath sounds, and no vomiting. The rule had a negative predictive value of 5,028 of 5,034 (99.9%; 95% confidence interval [CI] 99.7% to 100%), sensitivity of 197 of 203 (97%; 95% CI 94% to 99%), specificity of 5,028 of 11,841 (42.5%; 95% CI 41.6% to 43.4%), and negative likelihood ratio of 0.07 (95% CI 0.03 to 0.15). CONCLUSION A prediction rule consisting of 7 patient history and physical examination findings, and without laboratory or ultrasonographic information, identifies children with blunt torso trauma who are at very low risk for intra-abdominal injury undergoing acute intervention. These findings require external validation before implementation.

Use of the focused assessment with sonography for trauma (FAST) examination and its impact on abdominal computed tomography use in hemodynamically stable children with blunt torso trauma

BACKGROUND The aim of this study was to evaluate the variability of clinician-performed Focused Assessment with Sonography for Trauma (FAST) examinations and its impact on abdominal computed tomography (AbCT) use in hemodynamically stable children with blunt torso trauma (BTT). The FAST is used with variable frequency in children with BTT. METHODS We performed a planned secondary analysis of children (<18 years) with BTT. Patients with a Glasgow Coma Scale (GCS) score of less than 9, those with hypotension, and those taken directly to the operating suite were excluded. Clinicians documented their suspicion for intra-abdominal injury (IAI) as very low, less than 1%; low, 1% to 5%; moderate, 6% to 10%; high, 11% to 50%; or very high, greater than 50%. We determined the relative risk (RR) for AbCT use based on undergoing a FAST examination in each of these clinical suspicion strata. RESULTS Of 6,468 (median age, 11.8 years; interquartile range, 6.3–15.5 years) children who met eligibility, 887 (13.7%) underwent FAST examination before CT scan. A total of 3,015 (46.6%) underwent AbCT scanning, and 373 (5.8%) were diagnosed with IAI. Use of the FAST increased as clinician suspicion for IAI increased, 11.0% with less than 1% suspicion for IAI, 13.5% with 1% to 5% suspicion, 20.5% with 6% to 10% suspicion, 23.2% with 11% to 50% suspicion, and 30.7% with greater than 50% suspicion. The patients in whom the clinicians had a suspicion of IAI of 1% to 5% or 6% to 10% were significantly less likely to undergo a CT scan if a FAST examination was performed: RR, 0.83 (0.67–1.03); RR, 0.81 (0.72–0.91); RR, 0.85 (0.78–0.94); RR, 0.99 (0.94–1.05); and RR, 0.97 (0.91–1.05) for patients with clinician suspicion of IAI of less than 1%, 1% to 5%, 6% to 10%, 11% to 50%, and greater than 50%, respectively. CONCLUSION The FAST examination is used in a relatively small percentage of children with BTT. Use increases as clinician suspicion for IAI increases. Patients with a low or moderate clinician suspicion of IAI are less likely to undergo AbCT if they receive a FAST examination. A randomized controlled trial is required to more precisely determine the benefits and drawbacks of the FAST examination in the evaluation of children with BTT. LEVEL OF EVIDENCE Prognostic and epidemiologic study, II.

Intraosseous infusion: a review of methods and novel devices.

This is a review article of intraosseous infusion methods and devices.

Impact of Just-in-Time and Just-in-Place Simulation on Intern Success With Infant Lumbar Puncture.

BACKGROUND AND OBJECTIVE: Simulation-based skill trainings are common; however, optimal instructional designs that improve outcomes are not well specified. We explored the impact of just-in-time and just-in-place training (JIPT) on interns’ infant lumbar puncture (LP) success. METHODS: This prospective study enrolled pediatric and emergency medicine interns from 2009 to 2012 at 34 centers. Two distinct instructional design strategies were compared. Cohort A (2009–2010) completed simulation-based training at commencement of internship, receiving individually coached practice on the LP simulator until achieving a predefined mastery performance standard. Cohort B (2010–2012) had the same training plus JIPT sessions immediately before their first clinical LP. Main outcome was LP success, defined as obtaining fluid with first needle insertion and <1000 red blood cells per high-power field. Process measures included use of analgesia, early stylet removal, and overall attempts. RESULTS: A total of 436 first infant LPs were analyzed. The LP success rate in cohort A was 35% (13/37), compared with 38% (152/399) in cohort B (95% confidence interval for difference [CI diff], −15% to +18%). Cohort B exhibited greater analgesia use (68% vs 19%; 95% CI diff, 33% to 59%), early stylet removal (69% vs 54%; 95% CI diff, 0% to 32%), and lower mean number of attempts (1.4 ± 0.6 vs 2.1 ± 1.6, P < .01) compared with cohort A. CONCLUSIONS: Across multiple institutions, intern success rates with infant LP are poor. Despite improving process measures, adding JIPT to training bundles did not improve success rate. More research is needed on optimal instructional design strategies for infant LP.

RNA transcriptional biosignature analysis for identifying febrile infants with serious bacterial infections in the emergency department: a feasibility study.

Objectives To develop the infrastructure and demonstrate the feasibility of conducting microarray-based RNA transcriptional profile analyses for the diagnosis of serious bacterial infections in febrile infants 60 days and younger in a multicenter pediatric emergency research network. Methods We designed a prospective multicenter cohort study with the aim of enrolling more than 4000 febrile infants 60 days and younger. To ensure success of conducting complex genomic studies in emergency department (ED) settings, we established an infrastructure within the Pediatric Emergency Care Applied Research Network, including 21 sites, to evaluate RNA transcriptional profiles in young febrile infants. We developed a comprehensive manual of operations and trained site investigators to obtain and process blood samples for RNA extraction and genomic analyses. We created standard operating procedures for blood sample collection, processing, storage, shipping, and analyses. We planned to prospectively identify, enroll, and collect 1 mL blood samples for genomic analyses from eligible patients to identify logistical issues with study procedures. Finally, we planned to batch blood samples and determined RNA quantity and quality at the central microarray laboratory and organized data analysis with the Pediatric Emergency Care Applied Research Network data coordinating center. Below we report on establishment of the infrastructure and the feasibility success in the first year based on the enrollment of a limited number of patients. Results We successfully established the infrastructure at 21 EDs. Over the first 5 months we enrolled 79% (74 of 94) of eligible febrile infants. We were able to obtain and ship 1 mL of blood from 74% (55 of 74) of enrolled participants, with at least 1 sample per participating ED. The 55 samples were shipped and evaluated at the microarray laboratory, and 95% (52 of 55) of blood samples were of adequate quality and contained sufficient RNA for expression analysis. Conclusions It is possible to create a robust infrastructure to conduct genomic studies in young febrile infants in the context of a multicenter pediatric ED research setting. The sufficient quantity and high quality of RNA obtained suggests that whole blood transcriptional profile analysis for the diagnostic evaluation of young febrile infants can be successfully performed in this setting.

Precision of Impedance Cardiography Measurements of Cardiac Output in Pacemaker Patients

Objective hemodynamic assessment of pacemaker patients is necessary for gauging responses to changes in programming or other conditions that affect the circulation. Impedance cardiogrphy permits noninvasive, repetitive determinations of cardiac output at short intervals, but data regarding variability of this method in patients with pacemakers is unavailable. Thirty‐eight patients with implanted pacemakers (24 DDD, 14 VVI) and six normal subjects were studied, A computerized impedance cardiograph was used to calculate cardiac output from the product of the first derivative of the thoracic impedance signal (dZ/dt), the ventricular ejection time, and heart rate. Each patient was studied while supine after a period of at least 15 minutes of rest and repeated impedance measurements (about ten) were performed. Fourteen patients were studied in sinus rhythm, 24 were studied during DDD pacing, and 32 patients were studied during VVI pacing. Cardiac and stroke indices were calculated 706 times on the basis of 11,296 accepted beats. Variability was assessed by methods that analyzed serial measurements and variability between two consecutive and nonconsecutive measurements. The mean indices and coefficients of variation of two measurements and of serial measurements in sinus rhythm and during DDD pacing were 4%; in VVI it was 6%. The precision of impedance Cardiography in all pacing modes, as demonstrated by analysis of variability, indicates that detected changes of stroke volume and cardiac output > 7% on serial (two and more) measurements, performed by the same operator and during the same session, represent true hemodynamic alterations with 95% confidence. Conclusions are that the precision of impedance Cardiography may be comparable or superior to other commonly used techniques and that the data obtained by this technique is valuable investigationally and clinically.

Variability of cardiac output as determined by impedance cardiography in pacemaker patients

Hemodynamic assessment of pacemaker patients is necessary for gauging responses to changes in programming or other conditions affecting circulation. Impedance cardiography permits noninvasive determinations of cardiac output at short intervals but data regarding variability of this method in patients with pacemakers is unavailable. Thirty-eight patients with pacemakers (24 with DDD and 14 with VVI devices) and 6 normal subjects were studied. Each patient was studied in the supine position and repeated impedance measurements were obtained. Fourteen patients were studied during sinus rhythm, 24 were studied during DDD pacing, and 32 patients were studied during VVI pacing. Variability was assessed by methods that analyzed both serial measurements and variability between 2 consecutive and nonconsecutive measurements. The mean indexes and coefficients of variation of 2 and serial measurements in sinus rhythm and DDD were 4%; in VVI it was 6%. The precision of impedance cardiography in all pacing modes, as demonstrated by analysis of variability, indicates that detected changes of stroke volume and cardiac output > 7% on serial (2 and more) measurements, performed by the same operator and during the same session, represent true hemodynamic alterations with 95% confidence. The precision of impedance cardiography demonstrated may be comparable or superior to other frequently used techniques, and the data obtained are valuable both investigationally and clinically.

A Multicenter Study of the Risk of Intra-Abdominal Injury in Children After Normal Abdominal Computed Tomography Scan Results in the Emergency Department

STUDY OBJECTIVE We determine whether intra-abdominal injury is rarely diagnosed after a normal abdominal computed tomography (CT) scan result in a large, generalizable sample of children evaluated in the emergency department (ED) after blunt torso trauma. METHODS This was a planned analysis of data collected during a prospective study of children evaluated in one of 20 EDs in the Pediatric Emergency Care Applied Research Network. The study sample consisted of patients with normal results for abdominal CT scans performed in the ED. The principal outcome measure was the negative predictive value of CT for any intra-abdominal injury and those undergoing acute intervention. RESULTS Of 12,044 enrolled children, 5,380 (45%) underwent CT scanning in the ED; for 3,819 of these scan the results were normal. Abdominal CT had a sensitivity of 97.8% (717/733; 95% confidence interval [CI] 96.5% to 98.7%) and specificity of 81.8% (3,803/4,647; 95% CI 80.7% to 82.9%) for any intra-abdominal injury. Sixteen (0.4%; 95% CI 0.2% to 0.7%) of the 3,819 patients with normal CT scan results later received a diagnosis of an intra-abdominal injury, and 6 of these underwent acute intervention for an intra-abdominal injury (0.2% of total sample; 95% CI 0.06% to 0.3%). The negative predictive value of CT for any intra-abdominal injury was 99.6% (3,803/3,819; 95% CI 99.3% to 99.8%); and for injury undergoing acute intervention, 99.8% (3,813/3,819; 95% CI 99.7% to 99.9%). CONCLUSION In a multicenter study of children evaluated in EDs after blunt torso trauma, intra-abdominal injuries were rarely diagnosed after a normal abdominal CT scan result, suggesting that safe discharge is possible for the children when there are no other reasons for admission.

Orthostatic Responses in Patients with ODD Pacemakers: Signs of Autonomic Dysfunction

Responses to orthostasis may be altered in states associated with autonomic dysfunction. Computerized impedance cardiography, a noninvasive method for continuous assessment of stroke volume and mean blood pressure, was utilized to study the postural hemodynamic changes in eight normal and 27 patients with DDD pacemakers. Twenty patients with complete heart block (five with heart failure) were studied in the VDD mode and seven patients with sick sinus syndrome were assessed in DVI (four] or VDD (three). The results with pacemaker patients are significantly different from those observed in normal. Pacemaker patient responses to standing included: (1) a reduction in systolic, diastolic, and mean blood pressure; (2) an increase in heart rate in patients with intact sinus node function and no change in patients with sick sinus syndrome; and (3) stroke volume was unchanged in patients with sick sinus syndrome or heart failure and only modest reduction occurred in the remaining patients. Conclusions: (1) No reduction in stroke volume during upright posture occurs in DDD patients with sick sinus syndrome and this appears to be a compensatory reaction to an inadequate heart rate response to standing; (2) The hemodynamic response of DDD patients to the assumption of an upright posture is consistent with autonomic dysfunction; and (3) The primary cause for autonomic dysfunction in DDD patients may be the asynchronous ventricular depolarization caused by right ventricular pacing.

The Yale Observation Scale Score and the Risk of Serious Bacterial Infections in Febrile Infants

In our large prospective cohort of febrile infants, neither the YOS score nor unstructured clinician suspicion reliably identified infants with serious bacterial infections. OBJECTIVES: To assess the performance of the Yale Observation Scale (YOS) score and unstructured clinician suspicion to identify febrile infants ≤60 days of age with and without serious bacterial infections (SBIs). METHODS: We performed a planned secondary analysis of a prospective cohort of non–critically ill, febrile, full-term infants ≤60 days of age presenting to 1 of 26 participating emergency departments in the Pediatric Emergency Care Applied Research Network. We defined SBIs as urinary tract infections, bacteremia, or bacterial meningitis, with the latter 2 considered invasive bacterial infections. Emergency department clinicians applied the YOS (range: 6–30; normal score: ≤10) and estimated the risk of SBI using unstructured clinician suspicion (<1%, 1%–5%, 6%–10%, 11%–50%, or >50%). RESULTS: Of the 4591 eligible infants, 444 (9.7%) had SBIs and 97 (2.1%) had invasive bacterial infections. Of the 4058 infants with YOS scores of ≤10, 388 (9.6%) had SBIs (sensitivity: 51/439 [11.6%]; 95% confidence interval [CI]: 8.8%–15.0%; negative predictive value: 3670/4058 [90.4%]; 95% CI: 89.5%–91.3%) and 72 (1.8%) had invasive bacterial infections (sensitivity 23/95 [24.2%], 95% CI: 16.0%–34.1%; negative predictive value: 3983/4055 [98.2%], 95% CI: 97.8%–98.6%). Of the infants with clinician suspicion of <1%, 106 had SBIs (6.4%) and 16 (1.0%) had invasive bacterial infections. CONCLUSIONS: In this large prospective cohort of febrile infants ≤60 days of age, neither the YOS score nor unstructured clinician suspicion reliably identified those with invasive bacterial infections. More accurate clinical and laboratory predictors are needed to risk stratify febrile infants.