Victor Chernick

Bio: Victor Chernick is an academic researcher from University of Manitoba. The author has contributed to research in topics: Non-rapid eye movement sleep & Hypercapnia. The author has an hindex of 31, co-authored 100 publications receiving 2861 citations. Previous affiliations of Victor Chernick include Boston Children's Hospital.

A controlled trial of synthetic surfactant in infants weighing 1250 g or more with respiratory distress syndrome. The American Exosurf Neonatal Study Group I, and the Canadian Exosurf Neonatal Study Group.

Abstract: Background Surfactant-replacement therapy is now recognized as a life-saving and safe intervention in small premature infants, but there is little evidence concerning its risks and benefits in larger premature infants. Methods We conducted a placebo-controlled, blinded trial in 1237 infants with respiratory distress who were enrolled at 23 hospitals in the United States and 13 hospitals in Canada. At entry all the infants weighed at least 1250 g, were receiving mechanical ventilation, and had a ratio of arterial to alveolar oxygen tension below 0.22. The initial dose of either the synthetic surfactant (Exosurf, 5 ml per kilogram of body weight) or air (the placebo) was administered less than 24 hours after birth, with a second dose given 12 hours later. A total of 614 infants were assigned to receive surfactant, and 623 to receive placebo. Results Fewer infants in the surfactant group than in the placebo group died before 28 days of age or survived at 28 days with bronchopulmonary dysplasia (7 percent vs. 12 percent, P = 0.002). In the first 28 days of life, there were fewer deaths due to respiratory distress syndrome in the surfactant group (1 percent vs. 3 percent, P = 0.043), lower overall neonatal mortality (4 percent vs. 7 percent, P = 0.04), and a lower incidence of bronchopulmonary dysplasia (3 percent vs. 6 percent, P = 0.008). There was also a significantly lower incidence of pulmonary air leaks, intraventricular hemorrhage, patent ductus arteriosus, seizures, hypotension, and pulmonary hypertension in the surfactant group. The infants treated with surfactant were weaned from oxygen and mechanical ventilation significantly sooner than those given placebo, and they less often required high-frequency ventilation or extracorporeal membrane oxygenation. The primary side effect observed more frequently among the infants who received surfactant treatment was pulmonary hemorrhage (six infants vs. one infant, P = 0.055). Conclusions In infants weighing at least 1250 g at birth who have respiratory distress syndrome, treatment with two doses of synthetic surfactant improves survival and reduces perinatal morbidity.

Correlations of Mechanical Stability, Morphology, Pulmonary Surfactant, and Phospholipid Content in the Developing Lamb Lung

Abstract: Pressure-volume characteristics and surface tension measurements of the lamb of 120 to 130 days gestational age were typical of the mature lung in the upper lobes and the immature lung in the lower lobes. By term both upper and lower lobes had findings characteristic of the mature animal. Phospholipid concentration per milligram DNA and per cent saturated fatty acids on pulmonary phosphatidyl choline were relatively constant from 60 to 120 days gestational age; thereafter there was a significant increase in both measurements. These changes usually coincided with an increase in osmiophilic inclusion bodies in the large alveolar cell. A concentration of disaturated phosphatidyl choline per milligram DNA in excess of 0.170 mg per mg was associated with a minimal surface tension below 13 dynes per cm (p < 0.001). Newborn animal lungs contained over 3 times this critical concentration, whereas adult lungs contained 1.5 times this value. The excess disaturated phosphatidyl choline per milligram DNA may represent a reservoir of pulmonary surfactant.

Part 9: Post-Cardiac Arrest Care: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Abstract: There is increasing recognition that systematic post–cardiac arrest care after return of spontaneous circulation (ROSC) can improve the likelihood of patient survival with good quality of life. This is based in part on the publication of results of randomized controlled clinical trials as well as a description of the post–cardiac arrest syndrome. 1–3 Post–cardiac arrest care has significant potential to reduce early mortality caused by hemodynamic instability and later morbidity and mortality from multiorgan failure and brain injury. 3,4 This section summarizes our evolving understanding of the hemodynamic, neurological, and metabolic abnormalities encountered in patients who are initially resuscitated from cardiac arrest. The initial objectives of post–cardiac arrest care are to ● Optimize cardiopulmonary function and vital organ perfusion. ● After out-of-hospital cardiac arrest, transport patient to an appropriate hospital with a comprehensive post–cardiac arrest treatment system of care that includes acute coronary interventions, neurological care, goal-directed critical care, and hypothermia. ● Transport the in-hospital post–cardiac arrest patient to an appropriate critical-care unit capable of providing comprehensive post–cardiac arrest care. ● Try to identify and treat the precipitating causes of the arrest and prevent recurrent arrest.

Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth

Abstract: Background Respiratory morbidity including respiratory distress syndrome (RDS) is a serious complication of preterm birth and the primary cause of early neonatal mortality and disability. While researching the effects of the steroid dexamethasone on premature parturition in fetal sheep in 1969, Liggins found that there was some inflation of the lungs of lambs born at gestations at which the lungs would be expected to be airless. Liggins and Howie published the first randomised controlled trial in humans in 1972 and many others followed. Objectives To assess the effects of administering a course of corticosteroids to the mother prior to anticipated preterm birth on fetal and neonatal morbidity and mortality, maternal mortality and morbidity, and on the child in later life. Search methods We searched Cochrane Pregnancy and Childbirth's Trials Register (17 February 2016) and reference lists of retrieved studies. Selection criteria We considered all randomised controlled comparisons of antenatal corticosteroid administration (betamethasone, dexamethasone, or hydrocortisone) with placebo, or with no treatment, given to women with a singleton or multiple pregnancy, prior to anticipated preterm delivery (elective, or following spontaneous labour), regardless of other co-morbidity, for inclusion in this review. Most women in this review received a single course of steroids; however, nine of the included trials allowed for women to have weekly repeats. Data collection and analysis Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach. Main results This update includes 30 studies (7774 women and 8158 infants). Most studies are of low or unclear risk for most bias domains. An assessment of high risk usually meant a trial had potential for performance bias due to lack of blinding. Two trials had low risks of bias for all risk of bias domains. Treatment with antenatal corticosteroids (compared with placebo or no treatment) is associated with a reduction in the most serious adverse outcomes related to prematurity, including: perinatal death (average risk ratio (RR) 0.72, 95% confidence interval (CI) 0.58 to 0.89; participants = 6729; studies = 15; Tau² = 0.05, I² = 34%; moderate-quality); neonatal death (RR 0.69, 95% CI 0.59 to 0.81; participants = 7188; studies = 22), RDS (average RR 0.66, 95% CI 0.56 to 0.77; participants = 7764; studies = 28; Tau² = 0.06, I² = 48%; moderate-quality); moderate/severe RDS (average RR 0.59, 95% CI 0.38 to 0.91; participants = 1686; studies = 6; Tau² = 0.14, I² = 52%); intraventricular haemorrhage (IVH) (average RR 0.55, 95% CI 0.40 to 0.76; participants = 6093; studies = 16; Tau² = 0.10, I² = 33%; moderate-quality), necrotising enterocolitis (RR 0.50, 95% CI 0.32 to 0.78; participants = 4702; studies = 10); need for mechanical ventilation (RR 0.68, 95% CI 0.56 to 0.84; participants = 1368; studies = 9); and systemic infections in the first 48 hours of life (RR 0.60, 95% CI 0.41 to 0.88; participants = 1753; studies = 8). There was no obvious benefit for: chronic lung disease (average RR 0.86, 95% CI 0.42 to 1.79; participants = 818; studies = 6; Tau² = 0.38 I² = 65%); mean birthweight (g) (MD -18.47, 95% CI -40.83 to 3.90; participants = 6182; studies = 16; moderate-quality); death in childhood (RR 0.68, 95% CI 0.36 to 1.27; participants = 1010; studies = 4); neurodevelopment delay in childhood (RR 0.64, 95% CI 0.14 to 2.98; participants = 82; studies = 1); or death into adulthood (RR 1.00, 95% CI 0.56 to 1.81; participants = 988; studies = 1). Treatment with antenatal corticosteroids does not increase the risk of chorioamnionitis (RR 0.83, 95% CI 0.66 to 1.06; participants = 5546; studies = 15; moderate-quality evidence) or endometritis (RR 1.20, 95% CI 0.87 to 1.63; participants = 4030; studies = 10; Tau² = 0.11, I² = 28%; moderate-quality). No increased risk in maternal death was observed. However, the data on maternal death is based on data from a single trial with two deaths; four other trials reporting maternal death had zero events (participants = 3392; studies = 5; moderate-quality). There is no definitive evidence to suggest that antenatal corticosteroids work differently in any pre-specified subgroups (singleton versus multiple pregnancy; membrane status; presence of hypertension) or for different study protocols (type of corticosteroid; single course or weekly repeats). GRADE outcomes were downgraded to moderate-quality. Downgrading decisions (for perinatal death, RDS, IVH, and mean birthweight) were due to limitations in study design or concerns regarding precision (chorioamnionitis, endometritis). Maternal death was downgraded for imprecision due to few events. Authors' conclusions Evidence from this update supports the continued use of a single course of antenatal corticosteroids to accelerate fetal lung maturation in women at risk of preterm birth. A single course of antenatal corticosteroids could be considered routine for preterm delivery. It is important to note that most of the evidence comes from high income countries and hospital settings; therefore, the results may not be applicable to low-resource settings with high rates of infections. There is little need for further trials of a single course of antenatal corticosteroids versus placebo in singleton pregnancies in higher income countries and hospital settings. However, data are sparse in lower income settings. There are also few data regarding risks and benefits of antenatal corticosteroids in multiple pregnancies and other high-risk obstetric groups. Further information is also required concerning the optimal dose-to-delivery interval, and the optimal corticosteroid to use. We encourage authors of previous studies to provide further information, which may answer any remaining questions about the use of antenatal corticosteroids in such pregnancies without the need for further randomised controlled trials. Individual patient data meta-analysis from published trials is likely to answer some of the evidence gaps. Follow-up studies into childhood and adulthood, particularly in the late preterm gestation and repeat courses groups, are needed. We have not examined the possible harmful effects of antenatal corticosteroids in low-resource settings in this review. It would be particularly relevant to explore this finding in adequately powered prospective trials.

A controlled trial of antepartum glucocorticoid treatment for prevention of the respiratory distress syndrome in premature infants

Abstract: A controlled trial of betamethasone therapy was carried out in 282 mothers in whom premature delivery threatened or was planned before 37 weeks9 gestation, in the hope of reducing the incidence of neonatal respiratory distress syndrome by accelerating functional maturation of the fetal lung. Two hundred and thirteen mothers were in spontaneous premature labor. When necessary, ethanol or salbutamol infusions were used to delay delivery while steroid or placebo therapy was given. Delay for at least 24 hours was achieved in 77% of the mothers. In these unplanned deliveries, early neonatal mortality was 3.2% in the treated group and 15.0% in the controls (p 0.01). There were no deaths with hyaline membrane disease or intraventricular cerebral hemorrhage in infants of mothers who had received betamethasone for at least 24 hours before delivery. The respiratory distress syndrome occurred less often in treated babies (9.0%) than in controls (25.8%, p 0.003), but the difference was confined to babies of under 32 weeks9 gestation who had been treated for at least 24 hours before delivery (11.8% of the treated babies compared with 69.6% of the control babies p. 0.02). There may be an increased risk of fetal death in pregnancies complicated by severe hypertensionedema-proteinuria syndromes and treated with betamethasone, but no other hazard of steroid therapy was noted. We conclude that this preliminary evidence justifies further trials, but that further work is needed before any new routine procedure is established.

Part 14: Pediatric Advanced Life Support 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Abstract: In contrast to adults, cardiac arrest in infants and children does not usually result from a primary cardiac cause. More often it is the terminal result of progressive respiratory failure or shock, also called an asphyxial arrest. Asphyxia begins with a variable period of systemic hypoxemia, hypercapnea, and acidosis, progresses to bradycardia and hypotension, and culminates with cardiac arrest.1 Another mechanism of cardiac arrest, ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT), is the initial cardiac rhythm in approximately 5% to 15% of pediatric in-hospital and out-of-hospital cardiac arrests;2,–,9 it is reported in up to 27% of pediatric in-hospital arrests at some point during the resuscitation.6 The incidence of VF/pulseless VT cardiac arrest rises with age.2,4 Increasing evidence suggests that sudden unexpected death in young people can be associated with genetic abnormalities in myocyte ion channels resulting in abnormalities in ion flow (see “Sudden Unexplained Deaths,” below). Since 2010 marks the 50th anniversary of the introduction of cardiopulmonary resuscitation (CPR),10 it seems appropriate to review the progressive improvement in outcome of pediatric resuscitation from cardiac arrest. Survival from in-hospital cardiac arrest in infants and children in the 1980s was around 9%.11,12 Approximately 20 years later, that figure had increased to 17%,13,14 and by 2006, to 27%.15,–,17 In contrast to those favorable results from in-hospital cardiac arrest, overall survival to discharge from out-of-hospital cardiac arrest in infants and children has not changed substantially in 20 years and remains at about 6% (3% for infants and 9% for children and adolescents).7,9 It is unclear why the improvement in outcome from in-hospital cardiac arrest has occurred, although earlier recognition and management of at-risk patients on general inpatient units …