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Analyzing standing waves and reactive vibration power is often not sufficient to solve vibroacoustic problems. Damping is a key factor in mechanical vibrations, and it is frequently the result of waves propagating from energy sources to energy sinks and boundaries. Structural power flow is a means of representing the wave propagation within a structure. The difficulties encountered in computing the power flow from measured data are mainly due to the sensitivity of the existing methods to measurement noise. Most existing techniques rely on a few measurements and a finite difference approximation of spatial derivatives, which is known to amplify noise. In this paper a new method is proposed to compute the flexural power flow in beams from measured transverse accelerations. The Prony method is used to estimate both the wavenumber and the flexural wave equation coefficients from overdetermined measured data. The method is modified to impose the known relations existing between the complex exponentials in the wave equation solution. The formulae relating the wave component parameters to the power flow are well known. Numerical simulation results and experimental results are shown to illustrate the proposed method. The method has the potential to treat different wave types superposed, as it is often the case in truss structures.

Objective: Evaluate medical and nurse's practices offered in last 24 hours of life of children that died in 2 Brazilian PICU.Methods: The prospective study was based on: 1) medical chart's analysis of children that died between April- September/2008; 2) Semi- structured interview with the nurses (17). Researchers fielded out 3 protocols looking for data about interventions and care offered in the last 24 hours of life as well as the nurse's participations on EOL decision. According to the treatment offered in the last moments of life, children were classified in 2 groups: ‘full CPR’ and ‘no CPR’. The groups were compared.Results: 37 deaths were identified in this period (excluded 3 cases-brain death). The CPR was not performed in 50% of children. In 10 of 17 patients not reanimated, the plan for LSL was not recorded in the medical charts. In 80% patients of the ‘no CPR’ group, the vasoactive drugs infusion and ventilator parameters were maintained/increased without differences when compared to “full CPR”(p=1,0 e p=0,6). The nurse's practices evaluated using NAS score in the last 24 hours of life didn't differ even when the patient wasn't reanimated. When nurses were asked about participation on EOL decision, only 30% confirmed it.Conclusion: Brazilian studies have demonstrated that EOL practice has been a process centralized on the medical perspectives. We observed that nurses and medical attitudes before death didn't change even when the patients were considered terminal illness and the nurses rarely participated on the decision making process.

Background and aims: Burnout Syndrome is a response to chronic occupational stress that may affect to many professional categories. It leads to low quality professional care, poor doctorpatient relationship, decreased ability to express empathy and increased medical errors. We aimed to estimate the prevalence of Burnout Syndrome among pediatric intensivistsand compare to a group of general pediatricians.Methods: a case control study was conducted, selecting the pediatric intensivists working on duty in two regional and referral Brazilian PICU(PICU group) whereas an equal number of general pediatricians working with outpatients in the same hospitals were included as the control group(GPA group). Two blind researchers evaluated the both groups using the Portuguese version of the MBIMaslach Burnout Inventory scale. The protocol was approved by the PUCRS Ethics Committee.Results: 35 cases and 35 controls were evaluated. No demographic differences between the groups were observed. Burnout was present in 71% of the PICU group and in 29% of the GPA group(p< 0.01). The average score for all dimensions were higher for the emotional exhaustion(EE) and depersonalization(DE), and lower for professional accomplishment(PA) in the PICU group (P=0.0003). The multivariate analysis demonstrated that working in a PICU has independently associated with Burnout with an odds ratio 5.7(CI95%;1.9-16.7) when compared to general pediatrician.Conclusions: Burnout among pediatric intensivists is frequent and characteristically manifested by high levels of EE and DE and low levels of PA suggesting low quality of life, emotional suffering and professional dissatisfaction.

Objective: Evaluate modes of death and the treatment offered in the last 48 hours of life to patients dying in 10 Brazilian intensive care units (ICU) in a period of 2 years.Design and setting: Cross-sectional multicenter study based on medical chart review. The medical records of all patients that died in 7 Pediatric and 3 adult ICU belonging to university and tertiary hospitals in a period of two years were included. Deaths in the first 24 hours of admission to the PICU/ICU and brain death were excluded.Intervention: 2 fellows of each ICU were trained for filling a standard protocol (Kappa=0.9) to record demographic data and all medical management provided in the last 48 hours of life. The Student t test, Mann Whitney, chi-square and relative risk were used for data comparison.Measurements and main Results: 1,053 medical charts were included (59.4% adult patients). Life Support Limitation (LSL) was more frequent in the adult group (86% versus 43.5%; p< 0.001). Do not resuscitate order was the most common mode LSL in both groups (75% and 66%), whereas withholding / withdrawing were more frequent in the pediatric group (33.9% versus 24.9%; p=0.02). The LSL was rarely reported in the medical chart (52.6% and 33.7%) with a scarce family involvement in the decision making process (23.0%versus 8.7%; p< 0.001).Conclusion: LSL decision is frequent in Brazil but the most common practice is the DNR orders. The decision making process is predominantly centered on the medical perspective, with scarce participation of the family.

Background and method: ACTH stimulation test is used for the diagnosis of adrenal insufficiency in sepsis, but the optimal dosage of ACTH is still debatable. We, therefore, compared the efficacy of low (1µg/1.73m2) and standard (250µg/1.73m2) dosages of ACTH in identifying adrenal insufficiency in children with septic shock.Method: We evaluated 25 children admitted to PICU with catecholamine-dependent septic shock. Upon recruitment, a blood sample was collected for baseline cortisol determination. After an intravenous administration of low dose ACTH another blood sample was collected in 30 minutes for determination of cortisol response. Four hours after, a second intravenous ACTH stimulation test was performed, now using standard dose. Children were followed until PICU discharge.Results: The mean baseline cortisol was 773±421nmol/L. Baseline cortisol was not different between survivors and non-survivors (724±443 vs 795±241, p=0.16). Mean peak cortisol after low dose ACTH stimulation was 1157±451nmol/L, with mean change from baseline of 458nmol/L. Both mean peak cortisol (1160±445nmol/L) and mean change from baseline (746±458nmol/L) were higher after standard dose ACTH stimulation (p=0.045 and p< 0.01, respectively). There was a good correlation between peak cortisol after low and standard dose ACTH stimulation tests (r2=0.58). Out of the 25 children in the study, 7(28%) had AI. All of these children could be identified using the low dose ACTH stimulation test, but only 3(43%) could be identified using the standard dose ACTH stimulation test (p = 0.01) alone.Conclusion: Low dose ACTH for adrenal stimulation identifies more children with AI when compared with the standard dose test.

Background/aims: Neuroimmunoendocrine and metabolic dysfunctions are present in critical illness. We investigated whether insulin could reverse or limit these changes.Methods: Open-label randomized controlled physiology study of the effects of insulin during critical illness. 31 children with multiple organ dysfunction syndrome were recruited: 13children received continuous insulin infusion (0.1Unit/Kg/hr) and glucose was added if required to maintain glucose levels between 4.5 and 7.0mmol/L. Blood samples for neuroimmunoendocrine and metabolic evaluation were obtained before randomization, and 24 and 72hours later. A growth hormone(GH) oscillation profile was obtained during the first night.Results: At baseline both groups were similar. There was also no absolute difference in between the groups, at any time, in GH, IGF-1 and IGFBP-3. GH had higher relative increase in children receiving insulin, which suggests worsened GH resistance. By day 2, insulin decreased IGFBP-1 levels. At the same time insulin decreased free fatty acid levels, which was accompanied by increased LDL cholesterol and relative increase in HDL levels. Total cholesterol and triglycerides were unchanged. TNF-alpha and interleukin(IL)-1beta decreased in both groups, whereas IL-6 levels were significantly reduced significantly in children receiving insulin.Conclusions: Insulin does not reverse most of the neuroendocrine changes induced by stress of critical illness. However, it does appear to improve lipid metabolism (preserved LDL and HDL cholesterol) and down-regulate inflammation (decreased IL-6). These findings suggest that insulin in critical illness acts as a modulator of lipid dysfunction, which suggests new targets for future investigations.Figure 1

Injuries and deaths among children left unattended in motor vehicles are frequent and the rates are increasing. Injuries associated with motor vehicle power windows usually affect children, in particular children under 6 years of age. This case report is about a child who was asphyxiated because of a motor vehicle power window closing. She was rapidly resuscitated and recovered fully. A brief review of the literature, epidemiology, and preventive measures to avoid this type of injury is also presented.