Suresh Havalad

Energy expenditure in children with severe head injury: lack of agreement between measured and estimated energy expenditure.

BACKGROUND The purpose of this study was to test the hypotheses that estimates of resting energy expenditure (REE) vary significantly from measured energy expenditure in a population of head-injured children and are not accurate for use in determining nutrition needs in this population. METHODS This is a retrospective study of 30 children with severe head injury, with Glasgow Coma Scale (GCS) score of <8 and needing mechanical ventilation. Measured REE was obtained using indirect calorimetry. Estimated REEs were calculated using Harris-Benedict, World Health Organization (WHO), Schofield, and White formulas. Severity of illness was calculated using Pediatric Risk of Mortality (PRISM) score. Agreement between measured REE and estimated REE was tested using the Bland-Altman method. Correlation coefficient between PRISM score and measured REE was calculated using Spearman test. RESULTS More than half of the estimates of REE differed from measured REE by >10%. Significant disagreement between estimated REE and measured REE was demonstrated using the Bland-Altman method. There was no correlation between severity of illness and measured REE to explain the inaccuracies of REE estimates. CONCLUSION Energy expenditure in critically ill children cannot be estimated accurately; hence, nutrition for critically ill children with head injury should be provided according to measurement of REE to avoid the consequences of overfeeding or malnutrition.

Centhaquin improves resuscitative effect of hypertonic saline in hemorrhaged rats

BACKGROUND We observed that centhaquin, a cardiovascular active agent, reduces blood lactate levels. Because blood lactate is an important indicator of end-organ perfusion, we determined the resuscitative effect of centhaquin in hemorrhaged rats. MATERIALS AND METHODS Male, adult Sprague-Dawley rats (Harlan, Indianapolis, IN) were anesthetized with urethane, and a pressure catheter SPR-320 was placed in the left femoral artery, and a pressure-volume catheter SPR-869 was placed into the left ventricle through carotid artery. Hemorrhage was induced by withdrawing blood from the right femoral artery, and mean arterial pressure was maintained between 35 and 40 mm Hg for 30 min after which resuscitation was performed using normal saline (control), 3% hypertonic saline, or centhaquin dissolved in 3% hypertonic saline. Arterial blood pH, pO(2), pCO(2), lactate, hematocrit, and cardiovascular parameters were measured before the induction of hemorrhage (baseline), 30 min after induction of hemorrhagic shock, and every 60 min thereafter until the animal expired. RESULTS Hypertonic saline was effective in reducing blood lactate levels and improving cardiac output (CO) of hemorrhaged rats. Centhaquin dissolved in hypertonic saline produced a significantly greater decrease in blood lactate and increase in mean arterial pressure and CO compared with hypertonic saline in hemorrhaged rats. Fraction survival at 250 min was 0 when resuscitated with hypertonic saline, whereas it was 0.8 with centhaquin. CONCLUSIONS Centhaquin significantly improved the resuscitative effect of hypertonic saline by increasing CO, reducing blood lactate, and improving survival time of hemorrhaged rats.

Neuroprotective Effect of IRL-1620, an Endothelin B Receptor Agonist, on a Pediatric Rat Model of Middle Cerebral Artery Occlusion

Objective: The purpose of this study was to determine the potential neuroprotective effect of endothelin B (ETB) receptor agonist IRL-1620 treatment in a pediatric model of ischemic stroke. Design: A prospective, animal model study. Setting: An experimental laboratory. Subjects: Three-month-old male Wistar Han rats. Interventions: The rats underwent permanent middle cerebral artery occlusion (MCAO). At 2, 4, and 6 h post MCAO, they were treated with saline, IRL-1620 (5 μg/kg, IV), and/or ETB antagonist BQ788 (1 mg/kg, IV). Measurements and Main Results: The rats were evaluated over the course of 7 days for neurological and motor deficit, cerebral blood flow (CBF), and infarct volume. Young rats treated with IRL-1620 following MCAO improved significantly in neurological and motor assessments as compared to the vehicle-treated group, as measured by neurological score (P = 0.00188), grip test (P < 0.0001), and foot-fault error (P = 0.0075). CBF in the infarcted hemisphere decreased by 45–50% in all groups immediately following MCAO. After 7 days, CBF in the infarcted hemisphere of the IRL-1620 group increased significantly (P = 0.0007) when compared to the vehicle-treated group (+2.3 ± 23.3 vs. −45.4 ± 10.2%). Additionally, infarct volume was significantly reduced in IRL-1620-treated rats as compared to vehicle-treated rats (P = 0.0035, 41.4 ± 35.4 vs. 115.4 ± 40.9 mm3). Treatment with BQ788 blocked the effects of IRL-1620. Conclusions: IRL-1620 significantly reduced neurological and motor deficit as well as infarct volume while increasing CBF in a pediatric rat model of cerebral ischemia. These results indicate that selective ETB receptor stimulation may provide a novel therapeutic strategy in the treatment of pediatric ischemic stroke as has been demonstrated in adult ischemic stroke.

724: EFFECT OF IRL-1620, AN ENDOTHELIN-B RECEPTOR AGONIST, ON ISCHEMIC STROKE IN A PEDIATRIC RAT MODEL

Crit Care Med 2016 • Volume 44 • Number 12 (Suppl.) poor outcomes at 180 days. Subjects with poor outcome at day 180 had significantly more days with temperature readings >37.5oC (median 4 days vs. 2 days, p< 0.001). On multinomial logistic regression, number of days with temperature reading >37.5oC was an independent predictor of poor outcome at 180 days, after adjustment for age, thalamic location, stability IVH volume, GCS, CLR and any infection during the first week (OR:1.12 CI:1.02–1.24, p=0.024). Conclusions: Temperatures >37.5oC after spontaneous IVH are associated with poor functional outcome, and negate any enhanced enzymatic clot dissolution.

270: EFFECT OF TIDAL VOLUME ON LUNG INJURY IN RATS WITH LPS-INDUCED SEPTIC SHOCK

Crit Care Med 2016 • Volume 44 • Number 12 (Suppl.) patients are less likely to survive to discharge. We hypothesize that precipitating etiology of arrest may be a more important predictor of survival than age alone. Methods: We performed a retrospective review of an IHCA registry at a tertiary academic hospital from July 2007 to May 2016. Included were patients suffering IHCA for whom cardiopulmonary resuscitation was attempted. Arrest etiology was evaluated via a validated classification scheme containing 4 categories according to primary disease process that led directly to the arrest. Survival to discharge was the primary outcome. Neurologic status at discharge also was evaluated according to Cerebral Performance Category (score of 1-2 considered favorable). Results: A total of 967 index IHCA were identified. Mean age was 59 ± 17 years (range 16-99 years); 36% were female. Forty-four percent of arrests occurred out-of-ICU. Overall survival was 34%, and 27% of patients had a favorable neurologic outcome at discharge. Eighty-four percent had a non-shockable rhythm at time of arrest. Etiology of arrest was mixed: respiratory (n=332, 34%), neurological (n=24, 2.5%), circulatory (n=358, 37%), and dysrhythmias (n=253, 26%). Age was not significantly associated with survival (OR 1.00, 95% CI 0.99-1.01; p=.55) nor favorable neurologic outcome at discharge (OR 1.00, 95% CI 0.99-1.01; p=.74) in univariate models. In multivariable regression, the association between age and survival remained non-significant (OR 0.99, 95% CI 0.98-1.00; p=.10) after adjusting for arrest etiology and location. Both arrest etiology and location were independently associated with survival and favorable neurologic outcome. Conclusions: In our large single-center cohort, age did not predict survival nor neurologic outcome after IHCA. By contrast, arrest etiology predicted survival independent of age and arrest location. These findings may help individualize treatment recommendations, guided by patient-specific risk factors for each arrest etiology.