Objective To test the hypothesis that heart rate characteristics (HRC) monitoring improves neonatal outcomes. Study design We conducted a two-group, parallel, individually randomized controlled ...clinical trial of 3003 very low birth weight infants in 9 neonatal intensive care units. In one group, HRC monitoring was displayed; in the other, it was masked. The primary outcome was number of days alive and ventilator-free in the 120 days after randomization. Secondary outcomes were mortality, number of ventilator days, neonatal intensive care unit stay, and antibiotic use. Results The mortality rate was reduced in infants whose HRC monitoring was displayed, from 10.2% to 8.1% (hazard ratio, 0.78; 95% CI, 0.61-0.99; P = .04; number needed to monitor = 48), and there was a trend toward increased days alive and ventilator-free (95.9 of 120 days compared with 93.6 in control subjects, P = .08). The mortality benefit was concentrated in infants with a birth weight <1000 g (hazard ratio, 0.74; 95% CI, 0.57-0.95; P = .02; number needed to monitor = 23). There were no significant differences in the other outcomes. Conclusion HRC monitoring can reduce the mortality rate in very low birth weight infants.
Apnea of prematurity (AOP) is found in >50% of premature infants and is almost universal in infants who are <1000 g at birth. The literature clearly defines clinically significant apnea in infants ...(breathing pauses that last for >20 seconds or for >10 seconds if associated with bradycardia or oxygen desaturation), but there is no consensus about the duration of apnea, the degree of change in oxygen saturation, or severity of bradycardia that should be considered pathologic. Although caregivers are able to respond successfully to apnea events with drugs (as well as physical and mechanical interventions) in the NICU, it remains unproven whether such interventions have any long-term effects. One of the most effective drugs, caffeine citrate, is currently labeled for short-term use only and within a limited gestational-age population. Clinicians often use off-label drugs that have been approved for gastroesophageal reflux disease, which is common in premature infants, with the belief that such treatments also have an impact on AOP, although this link has never been demonstrated. Key treatment issues include (1) lack of standardization for definition, diagnosis, and treatment of AOP, (2) unproven benefit of intervention, (3) lack of real-time data documenting AOP events, (4) unevaluated sustained treatment improvement at 7 days or later, (5) failure to address confounding conditions, (6) unsubstantiated AOP-gastroesophageal reflux disease relationship, and (7) undetermined role of AOP affecting long-term neurodevelopmental outcomes. In addressing study-design issues, the pulmonary group identified (1) key questions about neonatal apnea, (2) methodologic requirements for study, (3) appropriate outcome measures, and (4) ethical considerations for future studies. This article describes a sample framework for the study of apnea in neonates and identifies future research needs. Plenary-session discussion points are also listed.
Periodic breathing (PB), regular cycles of short apneic pauses and breaths, is common in newborn infants. To characterize normal and potentially pathologic PB, we used our automated apnea detection ...system and developed a novel method for quantifying PB. We identified a preterm infant who died of sudden infant death syndrome (SIDS) and who, on review of her breathing pattern while in the neonatal intensive care unit (NICU), had exaggerated PB.We analyzed the chest impedance signal for short apneic pauses and developed a wavelet transform method to identify repetitive 10-40 second cycles of apnea/breathing. Clinical validation was performed to distinguish PB from apnea clusters and determine the wavelet coefficient cutoff having optimum diagnostic utility. We applied this method to analyze the chest impedance signals throughout the entire NICU stays of all 70 infants born at 32 weeks' gestation admitted over a two-and-a-half year period. This group includes an infant who died of SIDS and her twin.For infants of 32 weeks' gestation, the fraction of time spent in PB peaks 7-14 d after birth at 6.5%. During that time the infant that died of SIDS spent 40% of each day in PB and her twin spent 15% of each day in PB.This wavelet transform method allows quantification of normal and potentially pathologic PB in NICU patients.
Apnea of prematurity is an important and common clinical problem, and is often the rate-limiting process in NICU discharge. Accurate detection of episodes of clinically important neonatal apnea using ...existing chest impedance (CI) monitoring is a clinical imperative. The technique relies on changes in impedance as the lungs fill with air, a high impedance substance. A potential confounder, however, is blood coursing through the heart. Thus, the cardiac signal during apnea might be mistaken for breathing. We report here a new filter to remove the cardiac signal from the CI that employs a novel resampling technique optimally suited to remove the heart rate signal, allowing improved apnea detection. We also develop an apnea detection method that employs the CI after cardiac filtering. The method has been applied to a large database of physiological signals, and we prove that, compared to the presently used monitors, the new method gives substantial improvement in apnea detection.
IntroductionTiming of cord clamping and other cord management strategies may improve outcomes at preterm birth. However, it is unclear whether benefits apply to all preterm subgroups. Previous and ...current trials compare various policies, including time-based or physiology-based deferred cord clamping, and cord milking. Individual participant data (IPD) enable exploration of different strategies within subgroups. Network meta-analysis (NMA) enables comparison and ranking of all available interventions using a combination of direct and indirect comparisons.Objectives(1) To evaluate the effectiveness of cord management strategies for preterm infants on neonatal mortality and morbidity overall and for different participant characteristics using IPD meta-analysis. (2) To evaluate and rank the effect of different cord management strategies for preterm births on mortality and other key outcomes using NMA.Methods and analysisSystematic searches of Medline, Embase, clinical trial registries, and other sources for all ongoing and completed randomised controlled trials comparing cord management strategies at preterm birth (before 37 weeks’ gestation) have been completed up to 13 February 2019, but will be updated regularly to include additional trials. IPD will be sought for all trials; aggregate summary data will be included where IPD are unavailable. First, deferred clamping and cord milking will be compared with immediate clamping in pairwise IPD meta-analyses. The primary outcome will be death prior to hospital discharge. Effect differences will be explored for prespecified participant subgroups. Second, all identified cord management strategies will be compared and ranked in an IPD NMA for the primary outcome and the key secondary outcomes. Treatment effect differences by participant characteristics will be identified. Inconsistency and heterogeneity will be explored.Ethics and disseminationEthics approval for this project has been granted by the University of Sydney Human Research Ethics Committee (2018/886). Results will be relevant to clinicians, guideline developers and policy-makers, and will be disseminated via publications, presentations and media releases.Registration numberAustralian New Zealand Clinical Trials Registry (ANZCTR) (ACTRN12619001305112) and International Prospective Register of Systematic Reviews (PROSPERO, CRD42019136640).
Objective To compare the frequency and severity of apneic events in very low birth weight (VLBW) infants before and after blood transfusions using continuous electronic waveform analysis. Study ...design We continuously collected waveform, heart rate, and oxygen saturation data from patients in all 45 neonatal intensive care unit beds at the University of Virginia for 120 weeks. Central apneas were detected using continuous computer processing of chest impedance, electrocardiographic, and oximetry signals. Apnea was defined as respiratory pauses of >10, >20, and >30 seconds when accompanied by bradycardia (<100 beats per minute) and hypoxemia (<80% oxyhemoglobin saturation as detected by pulse oximetry). Times of packed red blood cell transfusions were determined from bedside charts. Two cohorts were analyzed. In the transfusion cohort, waveforms were analyzed for 3 days before and after the transfusion for all VLBW infants who received a blood transfusion while also breathing spontaneously. Mean apnea rates for the previous 12 hours were quantified and differences for 12 hours before and after transfusion were compared. In the hematocrit cohort, 1453 hematocrit values from all VLBW infants admitted and breathing spontaneously during the time period were retrieved, and the association of hematocrit and apnea in the next 12 hours was tested using logistic regression. Results Sixty-seven infants had 110 blood transfusions during times when complete monitoring data were available. Transfusion was associated with fewer computer-detected apneic events ( P < .01). Probability of future apnea occurring within 12 hours increased with decreasing hematocrit values ( P < .001). Conclusions Blood transfusions are associated with decreased apnea in VLBW infants, and apneas are less frequent at higher hematocrits.
As recently as the year 2000, 100% oxygen was recommended to begin resuscitation of depressed newborns in the delivery room. However, the most recent recommendations of the International Liaison ...Committee on Resuscitation counsel the prudent use of oxygen during resuscitation. In term and preterm infants, oxygen therapy should be guided by pulse oximetry that follows the interquartile range of preductal saturations of healthy term babies after vaginal birth at sea level. This article reviews the literature in this context, which supports the radical but judicious curtailment of the use of oxygen in resuscitation at birth.
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