Epidemiology of paediatric trauma presenting to US emergency departments: 2006-2012.

BACKGROUND: Traumatic injury is the leading cause of paediatric morbidity and mortality in the USA. We present updated national data on emergency department (ED) discharges for traumatic injury for a recent 7-year period. METHODS: We conducted a descriptive epidemiological analysis of the Nationwide Emergency Department Sample Survey, the largest and most comprehensive database in the USA, for 2006-2012. Among children and adolescents, we tracked changes in injury mechanism and severity, cost of care, injury intent and the role of trauma centres. RESULTS: There was an 8.3% (95% CI 7.7 to 8.9) decrease in the annual number of ED visits for traumatic injury in children and adolescents over the study period, from 8 557 904 (SE=5861) in 2006 to 7 846 912 (SE=5191) in 2012. The case-fatality rate was 0.04% for all injuries and 3.2% for severely injured children. Children and adolescents with high-mortality injury mechanisms were more than three times more likely to be treated at a level 1 trauma centre (OR=3.5, 95% CI 3.3 to 3.7), but were more no more likely to die (OR=0.96, 95% CI 0.93 to 1.00). Traumatic brain injury diagnoses increased 22.2% (95% CI 20.6 to 23.9) during the study period. Intentional assault accounted for 3% (SE=0.1) of all child and adolescent ED injury discharges and 7.2% (SE=0.3) of discharges among 15-19 year-olds. There was an 11.3% (95% CI 10.0 to 12.6) decline in motor vehicle injuries from 2009 to 2012. The total cost of care was $23 billion (SE=0.01), a 78% increase from 2006 to 2012. CONCLUSIONS: This analysis presents a recent portrait of paediatric trauma across the USA. These analyses indicate the important role and value of trauma centre care for injured children and adolescents, and that the most common causes and mechanisms of injury are preventable.

Prolonged length of stay in delayed cholecystectomy is not due to intraoperative or postoperative contributors.

BACKGROUND: Previous studies have reported that same-day laparoscopic cholecystectomy for acute cholecystitis is superior to delayed elective cholecystectomy. Although this practice is ideal, it requires significant hospital resources, particularly for an underprivileged inner-city population at a large, municipal hospital. We sought to evaluate the implementation of same-day laparoscopic cholecystectomy in a large, municipal hospital and assess the possible benefits of decreasing preoperative length of stay (LOS), particularly its effect on operative time and length of stay in patients with acute cholecystitis. MATERIALS AND METHODS: This was a retrospective chart review of patients treated for symptomatic gallstone disease between September 2012 and November 2013. Medical records were reviewed, and relevant data points were collected. Univariate and multivariate regressions were performed to assess the correlation between time to operation (<36 h [no delay] or >36 h [delay]) and the main outcomes (operative time and total length of stay). Inclusion criteria were patients age ≥18 y who underwent same-admission cholecystectomy and had a diagnosis of cholecystitis on pathology. Eighty-eight patients met all inclusion criteria. RESULTS: The mean (standard deviation) preoperative LOS was 76.2 (±48.6) h, the mean operative time was 2.3 (±1.1) h, and the mean postoperative LOS was 60.3 (±60.1) h. The average total LOS was 136 (±79.8) h. Operative times and postoperative LOS were similar for patients in the delay and no delay groups. Patients with >36 h wait before surgery had a total length of stay twice as long as patients with <36 h wait (152 versus 83.3 h; P = 0.0005). These findings remained significant when adjusted for age, sex, radiologic findings, number of preoperative tests, and pathology. CONCLUSIONS: Increased preoperative LOS is not associated with a significant increase in operative time. However, it was associated with significantly increased length of stay. Further analysis is needed to explore the potential cost savings of decreasing preoperative LOS.

Illusory spirals and loops in crystal growth.

The theory of dislocation-controlled crystal growth identifies a continuous spiral step with an emergent lattice displacement on a crystal surface; a mechanistic corollary is that closely spaced, oppositely winding spirals merge to form concentric loops. In situ atomic force microscopy of step propagation on pathological L-cystine crystals did indeed show spirals and islands with step heights of one lattice displacement. We show by analysis of the rates of growth of smaller steps only one molecule high that the major morphological spirals and loops are actually consequences of the bunching of the smaller steps. The morphology of the bunched steps actually inverts the predictions of the theory: Spirals arise from pairs of dislocations, loops from single dislocations. Only through numerical simulation of the growth is it revealed how normal growth of anisotropic layers of molecules within the highly symmetrical crystals can conspire to create features in apparent violation of the classic theory.