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This study was aimed at examining the associations between health disparities and physical activity, and their contributions to health and academic problems in schoolchildren.Pertinent data from a community-wide survey were analyzed, which included 2930 households with schoolchildren aged 7–14 years. Associations between the parents' self-reported race/ethnicity, parental education, household income, children's health status, physical activity, and academic problems were determined by Chi-square and logistic regression analyses. Contributory factors for children's health status, physical activity, and academic problems were predicted by logistic regression fitting.Within white/Caucasian children, 86.0% had very good/excellent health and 77.9% were physically active, values higher than those in Latino/Hispanic (77.8%, p

Over the past 20 years, hospitalists have emerged as a distinct group of pediatric practitioners. In August of 2014, the American Board of Pediatrics (ABP) received a petition to consider recommending that pediatric hospital medicine (PHM) be recognized as a distinct new subspecialty. PHM as a formal subspecialty raises important considerations related to: (1) quality, cost, and access to pediatric health care; (2) current pediatric residency training; (3) the evolving body of knowledge in pediatrics; and (4) the impact on both primary care generalists and existing subspecialists. After a comprehensive and iterative review process, the ABP recommended that the American Board of Medical Specialties approve PHM as a new subspecialty. This article describes the broad array of challenges and certain unique opportunities that were considered by the ABP in supporting PHM as a new pediatric subspecialty.

OBJECTIVE: In response to limitations in access to subspecialty care, I present personal observations and suggestions related to education of future pediatricians regarding development of critical thinking skills, care of complex and chronically ill patients, development of empathy, and restoration of responsibility that may help ameliorate this serious problem. Toward this end, I also offer 1 approach, a 24/7 telephone consultation network, for enriching interaction of primary care providers (PCPs) and subspecialists who can potentially provide rapid access to needed advice, reduce demand for subspecialty appointments, bolster decision-making and expertise, and realign resources with need. METHODS: Data were obtained from 579 requests by PCPs for telephone consultation by subspecialists in 8 areas (including child psychiatry). RESULTS: Of calls, 27% took CONCLUSIONS: Development of rapid telephone consultation networks could provide increased access to care for those children in greatest need, use limited resources more efficiently, foster collegial and productive relationships between medical providers, and increase expertise of PCPs and subspecialists.

American Pediatric Society 2009 Presidential Address—The Complexity of Pediatric Education in the 21st Century: What Can We Do?

* Abbreviation: EPA — : entrustable professional activity Within this compendium of perspectives and expert consensus about the education of subspecialty fellows, we are told that “ Recent advances in medical education allow the question of required duration of training to be examined using the metric of the pediatrics milestones.…” The consensus also reinforces that “Training should remain at three years for now, but over time the Board could allow a shorter or longer period to demonstrate expertise in a particular subspecialty. ” 1 Here we have the setting for 2 fundamental, but potentially conflicting, metrics, time versus maturation, that can collide and put substantial strain on resources intended to educate and certify fellows. If time is used as the gating mechanism for the advancement of fellows, it stands to reason that there will be heterogeneity of skills, knowledge, and maturity upon completion of the requisite time. Alternatively, if maturation is used as the gating mechanism, then there will likely be heterogeneity in the time to completion. It is worth exploring some of the consequences of these options. To the extent that the milestones (such as the Denver Developmental Screening Test) and entrustable professional activities (EPAs; such as the driver’s road test) will provide a blueprint for assessing the maturation of a fellow, the potential benefit is a rigorous, reproducible, and logical method to recognize what competencies have been achieved throughout the course of education and clinical practice. In addition, this method should provide a means to track a fellow’s progress in real time, which would permit formative feedback and potential for midcourse adjustments and, even more importantly, for self-directed learning and development. This approach requires validation of the evaluation, establishment of confidence intervals, measurement of interrater agreement, certainty that the maturational schema is properly ordered, and assessment of ease of application. It is essential to recognize that … Address correspondence to George Lister, MD, Department of Pediatrics, Yale School of Medicine, PO Box 208064, New Haven, CT 06520-8064. E-mail: george.lister{at}yale.edu

The American Academy of Pediatrics (AAP) strongly recommends the supine-only sleep position for infants and issued 2 more sudden infant death syndrome (SIDS) reduction recommendations: avoid bed sharing and use pacifiers during sleep. In this study, we investigated the following: 1) if mothers from at risk populations rate physicians as qualified to give advice about sleep practices and 2) if these ratings were associated with reports of recommended practice.A cross-sectional survey of mothers (N=2355) of infants aged8 months was conducted at Women, Infants, and Children (WIC) Program centers in 6 cities from 2006 to 2008. The predictor measures were maternal rating of physician qualification to give advice about 3 recommended sleep practices and reported nature of physician advice. The dependent measures were maternal report of usage of recommended behavior: 1) "infant usually placed supine for sleep," 2) "infant usually does not share a bed with an adult during sleep," and 3) "infant usually uses a pacifier during sleep."Physician qualification ratings varied by topic: sleep position (80%), bed sharing (69%), and pacifier use (60%). High ratings of physician qualification were associated with maternal reports of recommended behavior: supine sleep (adjusted odds ratio [AOR] 2.1, 95% confidence interval [CI], 1.6-2.6); usually no bed sharing (AOR 1.5, 95% CI, 1.2-1.9), and usually use a pacifier during sleep (AOR 1.2, 95% CI, 1.0-1.5).High maternal ratings of physician qualification to give advice on 2 of the 3 recommended sleep practices targeted to reduce the risk of SIDS were significantly associated with maternal report of using these behaviors. Lower ratings of physician qualification to give advice about these sleep practices may undermine physician effectiveness in promoting the recommended behavior.

Participants of the first colloquium of the Residency Review and Redesign in Pediatrics (R3P) Project considered possible scenarios affecting pediatric practice over the next 15 to 20 years and speculated about the knowledge and skills that pediatricians would need to care for children, adolescents, and young adults in the future. They concluded that the imponderables and complexity of that undertaking fell into the category of a “wicked problem” with no unique solutions. The specifics of the future cannot be predicted, but the themes important to thinking about the future are clear and must be incorporated into thinking about pediatric residency education.

In 1,079 infants monitored for >700,000 hr at home for apnea or bradycardia, we found an association between infants having multiple events exceeding conventional or a priori defined more extreme thresholds and less favorable developmental outcome at 1 year of age than infants with few or no events. If it is necessary to prevent such events to minimize risk for developmental morbidity, there is reason to determine whether there are disturbances in advance of the apnea or bradycardia that herald their onset. In the 85 infants with at least 1 extreme event and 1 conventional event, we hypothesized that apnea and bradycardia do not occur de novo but rather are preceded by cardiorespiratory and hemoglobin O2 saturation changes. We compared recorded time intervals preceding these events, and we analyzed three preceding time intervals for each conventional and extreme event, and each non-event recording: Time-2 hr: up to 2 hr before; Time-1 hr: up to 1 hr before; and Time-75 sec: the 75 sec immediately preceding each event. O2 saturation progressively decreased preceding both conventional and extreme events, and progressive increases occurred in heart and breathing rate variability. Duration of respiratory pauses and of periodic breathing progressively increased preceding conventional events, respiratory rate variability increased immediately preceding conventional events and at 1 hr preceding extreme events, and O2 saturation decreased immediately preceding both conventional and extreme events. Thus, conventional and extreme events do not occur de novo but rather are preceded by autonomic instability of the cardiorespiratory system. Pediatr Pulmonol. 2008; 43:87–98. © 2007 Wiley-Liss, Inc.

OBJECTIVES. The risk for sudden infant death syndrome in black infants is twice that of white infants, and their parents are less likely to place them in the supine position for sleep. We previously identified barriers for parents to follow recommendations for sleep position. Our objective with this study was to quantify these barriers, particularly among low-income, primarily black mothers. DESIGN/METHODS. We conducted face-to-face interviews with 671 mothers, 64% of whom were black, who attended Women, Infants, and Children Program centers in Boston, Massachusetts, Dallas, Texas, Los Angeles, California, and New Haven, Connecticut. We used univariate analyses to quantify factors that were associated with choice of sleeping position and multivariate logistic regression to calculate adjusted odds ratios for the 2 outcome variables: “ever” (meaning usually, sometimes, or last night) put infant in the prone position for sleep and “usually” put infant in the supine position to sleep. RESULTS. Fifty-nine percent of mothers reported supine, 25% side, 15% prone, and 1% other as the usual position. Thirty-four percent reported that they ever placed infants in the prone position. Seventy-two percent said that a nurse, 53% a doctor, and 38% a female friend or relative provided source of advice. Only 42% reported that a nurse, only 36% a doctor, and only 15% a female friend or relative recommended the supine position for sleep. When a female friend or relative recommended the prone position, mothers were more likely ever to place their infants in the prone position and less likely usually to choose supine compared with those who received no advice from friends or relatives. When a doctor or a nurse recommended a nonsupine position, the mothers were less likely to choose supine compared with those who received no advice from a doctor or a nurse. Mothers who trusted the opinion of a doctor or a nurse about infant sleeping position were more likely to place their infants in the supine position. Half of the mothers believed that infants were more likely to choke when supine, and they were less likely to place their infants supine. Mothers who believed that infants are more comfortable in the prone position (36%) were more likely to place their infants prone. Twenty-nine percent believed that having their infants sleep with an adult helps prevent sudden infant death syndrome, and only 43% believed that sudden infant death syndrome is related to sleeping position. CONCLUSIONS. We identified specific barriers to placing infants in the supine position for sleep (lack of or wrong advice, lack of trust in providers, knowledge and concerns about safety and comfort) in low-income, primarily black mothers that should be considered when designing interventions to get more infants onto their back for sleep.

Background.—African American infants have a higher incidence of SIDS and increased risk of being placed in the prone position for sleep. Objective.—To determine new barriers and more information about previously identified barriers that interfere with adherence to the Back-to-Sleep recommendations among inner-city, primarily African Americans. Design/Methods.—We conducted 9 focus groups with caregivers of infants and young children from women, infants, and children centers and clinics in New Haven and Boston. Themes were identified using standard qualitative techniques. Results.—Forty-nine caregivers participated, of whom 86% were African American, 6% were Hispanic, 4% were white, and 4% were other. Four themes were identified: 1) Safety: Participants chose the position for their infants based on which position they believed to be the safest. Some participants did not choose to put their infants in the supine position for sleep because they feared their infants would choke; 2) Advice: Participants relied on the advice of more experienced female family members. Health care providers were not uniformly a trusted source of advice; 3) Comfort: Participants made choices about their infants sleeping positions based on their perceptions of whether the infants appeared comfortable. Participants thought that their infants appeared more comfortable in the prone position; 4) Knowledge: Some participants had either limited or erroneous knowledge about the Back-to-Sleep recommendations. Conclusions.—We identified multiple barriers to adherence to recommendations regarding infant sleep position. Data obtained from these focus groups could be used to design educational interventions aimed at improving communication about and adherence to the Back-to-Sleep recommendations.

In 1981, the Report of the Medical Consultants on the Diagnosis of Death established guidelines for the diagnosis of brain death and, in 1995, the American Academy of Neurology published practice parameters to standardize determination of brain death. In 1987, the American Academy of Pediatrics established guidelines for determining brain death in children. Despite the establishment of these guidelines, the declaration of "death" based on the cessation of brain function remains complex and controversial. In this review are discussed the current guiding principles and the controversies in the diagnosis of brain death in children.

As part of the Collaborative Home Infant Monitoring Evaluation (CHIME) we compared apnea identified by a customized home monitor using respiratory inductance plethysmography (RIP) with simultaneously recorded polysomnography-acquired nasal end-tidal CO2 (Pet CO2 ) and nasal/oral thermistor in 422 infants during overnight laboratory recordings to determine concordance between techniques, sources of disagreement, and capacity of RIP to detect obstructed breaths within an apnea. Among 233 episodes of apnea identified by at least one method as ⩾ 16 s, 120 were observed by the CHIME monitor, 219 by Pet CO2 , and 163 by thermistor. The positive predictive value of the CHIME-identified apnea was 89.2% (95% CI 83, 95) and 73% (95% CI 65, 81) for Pet CO2 and thermistor, respectively. However, the sensitivity of the CHIME monitor in identifying events detected by the other methods was only ∼ 50%. Among 87 apnea events identified by all three techniques, no two methods showed high agreement in measurement of apnea d...

There are numerous reports of cardiorespiratory patterns in infants on home monitors, but no data to determine whether "experts" agree on the description of these patterns. Therefore, we evaluated agreement among four experienced investigators and five trained technicians who assessed independently the same sample of physiologic waveforms recorded from infants enrolled in a multicenter study. The monitor used respiratory inductance plethysmography and recorded waveforms for apnea > or = 16 s or a heart rate or = 5 s. The investigators and technicians initially assessed 88 waveforms. After additional training, the technicians assessed another 113 additional waveforms. In categorizing waveforms as apnea present or absent, agreement among technicians improved considerably with additional training (kappa 0.65 to 0.85). For categorizing waveforms as having bradycardia present versus absent, the trends were the same. Agreement in measurement of apnea duration also improved considerably with additional training (intraclass correlation 0.33-0.83). Agreement in measurement of bradycardia duration was consistently excellent (intraclass correlation 0.86-0.99). Total agreement was achieved among technicians with additional training for measurement of the lowest heart rate during a bradycardia. When classifying apnea as including > or = 1, > or = 2, > or = 3, or > or = 4 out-of-phase breaths, agreement was initially low, but after additional training it improved, especially in categorization of apneas with > or = 3 or > or = 4 out-of-phase breaths (kappa 0.67 and 0.94, respectively). Although researchers and clinicians commonly describe events based on cardiorespiratory recordings, agreement amongst experienced individuals may be poor, which can confound interpretation. With clear guidelines and sufficient training raters can attain a high level of agreement in describing cardiorespiratory events.

Intrinsic properties of lung and chest wall tissues can lead to breathing rate (frequency [f]) and amplitude (tidal volume [VT]) dependence of respiratory system resistance (R) and elastance (E). To explore these dependencies on R and E within physiological limits of tidal volume and breathing frequencies during early childhood. we measured airway opening pressure (Pao) and flow (V'ao) in 15 anesthetized, paralyzed, intubated, and mechanically ventilated healthy children (age 1 day to 72 months; weight 2.5-21 kg) at multiple combinations of VT (6, 10, and 14 mL/kg) and frequency (10, 20, and 30 breaths/min). In each instance, R and E were estimated by multiple linear regression applied to the tracheal pressure, flow, and volume (V), assuming a simple series R-E model. R decreased substantially with increasing frequency and weight (Wt), but was unaffected by changes in VT (R = 764Wt(-0.91) x f(-0.57)). E decreased sharply with increasing Wt, was lower at higher VT, and was slightly, yet significantly, increased at higher frequency (E = 2,905Wt(-1.38) x VT(-0.18) x f(0.11)). Such frequency dependence of R and E is consistent with stress adaptive, or viscoelastic, properties of respiratory tissues. The small V dependence of E is similar to that observed in other species under healthy conditions and presumably reflects the combined nonlinear pressure-volume relationships of the healthy parenchymal and chest wall tissues. Lack of VT dependence of R at high inspiratory flow rates suggests that turbulent flows are either not an important form of energy dissipation in the lower airways of children or they are counterbalanced by a decrease in tissue damping at high VT. The above regression models represent the first attempt to quantify simultaneously the separate effects of lung growth as well as rate and amplitude of breathing on R and E. Similar equations based on a larger sample of healthy subjects can provide normative R and E values for comparison with mechanically ventilated children with lung disease.

Importance A strong association between infant bed sharing and sudden infant death syndrome or unintentional sleep-related death in infants has been established. Occurrences of unintentional sleep-related deaths among infants appear to be increasing. Objectives To determine the trends and factors associated with infant bed sharing from 1993 through 2010, including the association of physician advice on bed sharing. Design National Infant Sleep Position study conducted with annual telephone surveys. Setting The 48 contiguous states. Participants Nighttime caregivers of infants born within 7 months of each survey administration. Approximately 1000 interviews were completed annually. Main Outcomes and Measures Infant bed sharing as a usual practice. Results Of 18 986 participants, 11.2% reported an infant sharing a bed as a usual practice. Bed sharing increased from 1993 (6.5%) to 2010 (13.5%). Although bed sharing increased significantly among white respondents from 1993 to 2000 ( P P = .48). Black and Hispanic respondents reported an increase in bed sharing throughout the study period, with no difference between the earlier and later periods ( P = .63 and P = .77, respectively). After accounting for the study year, factors associated with increase in infant bed sharing as a usual practice included maternal educational level of less than high school compared with college or greater (adjusted odds ratio, 1.42 [95% CI, 1.12-1.79]); black (3.47 [2.97-4.05]), Hispanic (1.33 [1.10-1.61]), and other (2.46 [2.03-2.97]) maternal race or ethnicity compared with white race; household income of less than $20 000 (1.69 [1.44-1.99]) and $20 000 to $50 000 (1.29 [1.14-1.45]) compared with greater than $50 000; living in the West (1.61 [1.38-1.88]) or the South (1.47 [1.30-1.66]) compared with the Midwest; infants younger than 8 weeks (1.45 [1.21-1.73]) or ages 8 to 15 weeks (1.31 [1.17-1.45]) compared with 16 weeks or older; and being born prematurely compared with full-term (1.41 [1.22-1.62]). Almost 46% of the participants reported talking to a physician about bed sharing. Compared with those who did not receive advice from a physician, those who reported their physicians had a negative attitude were less likely to have the infant share a bed (adjusted odds ratio, 0.66 [95% CI, 0.53-0.82]), whereas a neutral attitude was associated with increased bed sharing (1.38 [1.05-1.80]). Conclusions and Relevance Our finding of a continual increase in bed sharing throughout the study period among black and Hispanic infants suggests that the current American Academy of Pediatrics recommendation about bed sharing is not universally followed. The factors associated with infant bed sharing may be useful in evaluating the impact of a broad intervention to change behavior.

Recruitment and Development of Academic Pediatricians: Departmental Commitments to Promote Success

Objectives: To determine the relationship between the advice mothers receive about infant sleep position and the actual position they place their infants in to sleep and to understand modifiers of that relationship, especially beliefs about infant comfort and safety. Design: Cross-sectional, face-to-face interviews. Setting: Women, Infants, and Children centers in the United States from 2006 to 2008. Participants: A t otal o f 2 299 p redominantly African American mothers of infants younger than 8 months. Main Exposure: Advice received and beliefs about infant sleep position. Outcome Measure: Usually supine infant sleep position. Results: Advice for exclusively supine infant sleep position from family (OR, 1.6; 95% CI, 1.17-2.17), doctors (OR, 2.28; 95% CI, 1.77-2.93), nurses (OR, 1.46; 95% CI, 1.151.84), or the media (OR, 1.54; 95% CI, 1.22-1.95) was associated with usually placing an infant supine to sleep. Additional sources of advice for exclusively supine position significantly increase the odds that an infant will be placed supine. Mothers who believe an infant is comfortable supine are more likely to place their infants on their backs to sleep (OR, 4.05; 95% CI, 2.51-6.53). Mothers who believe an infant will choke on its back are less likely to place their infants supine (OR, 0.36; 95% CI, 0.24-0.54). Conclusion: Among predominantly African American mothers, increasing advice for exclusively supine sleep and addressing concerns about infant comfort and choking remain critical to getting more infants on their back to sleep.

To determine trends and factors associated with choice of infant sleeping position.Annual nationally representative telephone surveys from 1993 through 2007.Forty-eight contiguous states of the United States.Nighttime caregivers of infants born within the last 7 months; approximately 1000 interviews were given each year. Main Outcome Measure Whether infant is usually placed supine to sleep.For the 15-year period, supine sleep increased (P.001) and prone sleep decreased (P.001) for all infants, with no significant difference in trend by race. Since 2001, a plateau has been reached for all races. Factors associated with increased supine sleep between 1993 and 2007 included time, maternal race other than African American, higher maternal educational level, not living in Southern states, first-born infant, and full-term infant. The effect of these variables was reduced when variables related to maternal concerns about infant comfort, choking, and advice from physicians were taken into account. Between 2003 and 2007, there was no significant yearly increase in supine sleep. Choice of sleep position could be explained almost entirely by caregiver concern about comfort, choking, and advice. Race no longer was a significant predictor.Since 2001, supine sleep has reached a plateau, and there continue to be racial disparities. There have been changes in factors associated with sleep position, and maternal attitudes about issues such as comfort and choking may account for much of the racial disparity in practice. To decrease sudden infant death syndrome rates, we must ensure that public health measures reach the populations at risk and include messages that address concerns about infant comfort and choking.

Extracorporeal membrane oxygenation (ECMO) is a means of diverting a fraction or all of the circulation through a device that permits gas exchange across a permeable membrane. The site of removal and the site of return of blood are dictated primarily by practical considerations based on the volume of flow of blood to be diverted and whether a particular organ is to be bypassed. The prototype of extracorporeal oxygenation is heart-lung bypass, used for various types of cardiac surgery, in which the entire venous return is diverted through an oxygenator (bubble or membrane type) and returned to the aorta. Since the earliest reports of the use of ECMO in neonates, venoarterial bypass has been the preferred route, with blood drained from the right atrium and returned either to the carotid artery or to the femoral artery, although the former seems to have been used most often (2;4;11;12;14;18). In some reports, veno-venous bypass has also been accomplished with removal of blood from the right atrium and return into the umbilical or femoral vein (13;19). Gas exchange across the lung may also continue, although the ventilator rate, tidal volume, or peak inspiratory pressure are usually reduced markedly during the period of extracorporeal oxygenation. Anticoagulation is accomplished with few problems by infusion of heparin sulfate throughout the duration of the procedure. There now have been enough reports in the literature (individual cases or series of patients) to demonstrate that the procedure can be carried out with a minimum of technical difficulties in newborn infants (2;3;4;11;12;18), although the selection of “appropriate” patients reduces the morbidity and technical challenges of the procedure.

Persistent pulmonary hypertension of the newborn or persistent fetal circulation is a clinical syndrome that is usually apparent within the first 2 days after birth because of the presence of hypoxemia (2;12;19). The syndrome was first described in an abstract by Gersony, Due, and Sinclair (6) in 1969. Two infants were reported who had “RV decompensation, cyanosis and clear lung fields… in the absence of recognizable cardiac, pulmonary, hematologic or CNS disease.” The syndrome has been associated with aspiration of meconium, diaphragmatic hernia, asphyxia, hemorrhage, shock, and maternal infection (4;18). In other cases, there is no clear antecedent event. Despite considerable interest in the problem and a wealth of research related to pulmonary vasoregulation and vascular development in the fetus and newborn, the etiology of the syndrome remains obscure 20 years since its recognition.

In 1,079 infants monitored for700,000 hr at home for apnea or bradycardia, we found an association between infants having multiple events exceeding conventional or a priori defined more extreme thresholds and less favorable developmental outcome at 1 year of age than infants with few or no events. If it is necessary to prevent such events to minimize risk for developmental morbidity, there is reason to determine whether there are disturbances in advance of the apnea or bradycardia that herald their onset. In the 85 infants with at least 1 extreme event and 1 conventional event, we hypothesized that apnea and bradycardia do not occur de novo but rather are preceded by cardiorespiratory and hemoglobin O2 saturation changes. We compared recorded time intervals preceding these events, and we analyzed three preceding time intervals for each conventional and extreme event, and each non-event recording: Time-2 hr: up to 2 hr before; Time-1 hr: up to 1 hr before; and Time-75 sec: the 75 sec immediately preceding each event. O2 saturation progressively decreased preceding both conventional and extreme events, and progressive increases occurred in heart and breathing rate variability. Duration of respiratory pauses and of periodic breathing progressively increased preceding conventional events, respiratory rate variability increased immediately preceding conventional events and at 1 hr preceding extreme events, and O2 saturation decreased immediately preceding both conventional and extreme events. Thus, conventional and extreme events do not occur de novo but rather are preceded by autonomic instability of the cardiorespiratory system.

My challenge here is to convey the lessons I have learned in serving as a mentor to budding physicianscientists; yet, this is not as easy as it seems at first blush for at least two reasons. First, so many outstanding scientists, including Nobel laureates, have extolled the virtues of their own mentors who were central to their success. Thus, it feels pretentious to explain how to be a mentor, as if I have now reached some Olympian stature. Furthermore, I realize that those who might at first glance at this article have already thought about the topic throughout their career and acknowledged its importance. I certainly do not wish to provide obvious and unneeded advice.

Coma following a hypoxic-ischemic event is a serious condition and common reason for admission to the pediatric intensive care unit. Because coma has a high rate of mortality and morbidity in children, and the clinician may be unsure of the outcome very early in the course, it is important to have strategies to define prognosis. Although most studies have been conducted in adults, we review factors predicting outcome from coma of nontraumatic causes in infants and children. We consider the relation between physical findings, commonly accessible laboratory tools, and outcome, and comment on some newer techniques that may become more available for clinical purposes.

ContextHome monitors designed to identify cardiorespiratory events are frequently used in infants at increased risk for sudden infant death syndrome (SIDS), but the efficacy of such devices for this use is unproven.ObjectiveTo test the hypothesis that preterm infants, siblings of infants who died of SIDS, and infants who have experienced an idiopathic, apparent life-threatening event have a greater risk of cardiorespiratory events than healthy term infants.DesignLongitudinal cohort study conducted from May 1994 through February 1998.SettingFive metropolitan medical centers in the United States.ParticipantsA total of 1079 infants (classified as healthy term infants and 6 groups of those at risk for SIDS) who, during the first 6 months after birth, were observed with home cardiorespiratory monitors using respiratory inductance plethysmography to detect apnea and obstructed breathing.Main Outcome MeasuresOccurrence of cardiorespiratory events that exceeded predefined conventional and extreme thresholds as recorded by the monitors.ResultsDuring 718 358 hours of home monitoring, 6993 events exceeding conventional alarm thresholds occurred in 445 infants (41%). Of these, 653 were extreme events in 116 infants (10%), and of those events with apnea, 70% included at least 3 obstructed breaths. The frequency of at least 1 extreme event was similar in term infants in all groups, but preterm infants were at increased risk of extreme events until 43 weeks' postconceptional age.ConclusionsIn this study, conventional events are quite common, even in healthy term infants. Extreme events were common only in preterm infants, and their timing suggests that they are not likely to be immediate precursors to SIDS. The high frequency of obstructed breathing in study participants would likely preclude detection of many events by conventional techniques. These data should be important for designing future monitors and determining if an infant is likely to be at risk for a cardiorespiratory event.

* Abbreviations: SIDS = : sudden infant death syndrome • ECG = : electrocardiogram • LQTS = : long QT syndrome We read with interest the article on the proposed association of prolonged QT interval and the sudden infant death syndrome (SIDS) by Schwartz et al.1 Recognizing the previous failures to determine cause(s) for SIDS and the risks of changing practice in response to one study, we wish to take this opportunity to place the findings of the study in perspective and reflect on directions that might be pursued. Although the mechanism for SIDS (the most common cause of death from 1 month to 1 year of age) remains unknown, certain factors, such as smoking during pregnancy and sleep position of the infant lter the risk of SIDS.2–7 The hypothesis that there is a relationship between SIDS and prolonged QT has been previously raised by Schwartz8 and other authors,9–12 and disputed by some,13–15 but the recent data by Schwartz et al1 are the most compelling to date. Schwartz et al obtained electrocardiogram (ECG) recordings 3 to 4 days after birth in 34 443 newborn infants, 24 of whom died within the first year after birth with a diagnosis of SIDS. The authors found that these 24 infants had an average QT interval (corrected for heart rate) that was longer than in 9725 randomly selected living infants and longer than in 10 infants who died of other causes. Accordingly, this report raises several important questions. What is the cause of the long QT interval in the infants? Schwartz et al1 suggest that the prolonged QT might be caused by: a) different rates of development of the right and left sympathetic nerves rendering the infant susceptible to an arrhythmia during sudden increases in sympathetic activity8 ,16 ,17; or b) mutation in one of the genes encoding sodium or potassium channels, as has been identified … Address correspondence to George Lister, MD, Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, PO Box 208064, New Haven, CT 06520-8064.

Infant polysomnography (IPSG) is an increasingly important procedure for studying infants with sleep and breathing disorders. Since analyses of these IPSG data are subjective, an equally important issue is the reliability or strength of agreement among scorers (especially among experienced clinicians) of sleep parameters (SP) and sleep states (SS). One basic issue of this problem was examined by proposing and testing the hypothesis that infant SP and SS ratings can be reliably scored at substantial levels of agreement, that is, kappa (kappa) > or = 0.61. In light of the importance of IPSG reliability in the collaborative home infant monitoring evaluation (CHIME) study, a reliability training and evaluation process was developed and implemented. The bases for training on SP and SS scoring were CHIME criteria that were modifications and supplements to Anders, Emde, and Parmelee (10). The kappa statistic was adopted as the method for evaluating reliability between and among scorers. Scorers were three experienced investigators and four trainees. Inter- and intrarater reliabilities for SP codes and SSs were calculated for 408 randomly selected 30-second epochs of nocturnal IPSG recorded at five CHIME clinical sites from healthy full term (n = 5), preterm (n = 4), apnea of infancy (n = 2), and siblings of the sudden infant death syndrome (SIDS) (n = 4) enrolled subjects. Infant PSG data set 1 was scored by both experienced investigators and trained scorers and was used to assess initial interrater reliability. Infant PSG data set 2 was scored twice by the trained scorers and was used to reassess inter-rater reliability and to assess intrarater reliability. The kappa s for SS ranged from 0.45 to 0.58 for data set 1 and represented a moderate level of agreement. Therefore, rater disagreements were reviewed, and the scoring criteria were modified to clarify ambiguities. The kappa s and confidence intervals (CIs) computed for data set 2 yielded substantial inter-rater and intrarater agreements for the four trained scorers; for SS, the kappa = 0.68 and for SP the kappa s ranged from 0.62 to 0.76. Acceptance of the hypothesis supports the conclusion that the IPSG is a reliable source of clinical and research data when supported by significant kappa s and CIs. Reliability can be maximized with strictly detailed scoring guidelines and training.

Peters, Jochen K., George Lister, Ethan R. Nadel, and Gary W. Mack. Venous and arterial reflex responses to positive-pressure breathing and lower body negative pressure. J. Appl. Physiol. 82(6): 1889–1896, 1997.—We examined the relative importance of arteriolar and venous reflex responses during reductions in cardiac output provoked by conditions that increase [positive end-expiratory pressure (PEEP)] or decrease [lower body negative pressure (LBNP)] peripheral venous filling. Five healthy subjects were exposed to PEEP (10, 15, 20, and 25 cmH2O) and LBNP (−10, −15, −20, and −25 mmHg) to induce progressive but comparable reductions in right atrial transmural pressure (control to minimum): from 5.9 ± 0.4 to 1.8 ± 0.7 and from 6.5 ± 0.6 to 2.0 ± 0.2 mmHg with PEEP and LBNP, respectively. Cardiac output (impedance cardiography) fell less during PEEP than during LBNP (from 3.64 ± 0.21 to 2.81 ± 0.21 and from 3.39 ± 0.21 to 2.14 ± 0.24 l ⋅ min−1 ⋅ m−2with PEEP and LBNP, respectively), and mean arterial pressure increased. We observed sustained increases in forearm vascular resistance (i.e., forearm blood flow by venous occlusion plethysmography) and systemic vascular resistance that were greater during LBNP: from 19.7 ± 2.91 to 27.97 ± 5.46 and from 20.56 ± 2.48 to 50.25 ± 5.86 mmHg ⋅ ml−1 ⋅ 100 ml tissue−1 ⋅ min ( P < 0.05) during PEEP and LBNP, respectively. Venomotor responses (venous pressure in the hemodynamically isolated limb) were always transient, significant only with the greatest reduction in right atrial transmural pressure, and were similar for LBNP and PEEP. Thus arteriolar rather than venous responses are predominant in blood volume mobilization from skin and muscle, and venoconstriction is not intensified with venous engorgement during PEEP.

We previously observed young lambs to be more tolerant of hypoxia; compared with older lambs, they accumulate lactate at a slower rate during comparable reduction in cardiac output, and have a greater percent decrease in cardiac output before onset of systemic lactate accumulation. To determine the mechanism of lactic acidosis and the cause for this "tolerance," we reduced cardiac output progressively in seven chronically catheterized conscious lambs (16.4 + 5.1 d) and measured hepatic and gastrointestinal (GI) blood flow (radioactive microspheres) and delivery, uptake, and extraction of lactate and O2. Hepatic O2 consumption declined proportionately below a critical hepatic O2 delivery (approximately 2 mL O2/min/kg), corresponding to the systemic O2 delivery associated with the onset of systemic lactate accumulation. As hepatic O2 delivery decreased below the critical value, there was initially net hepatic lactate uptake and then a change to net production when the O2 delivery decreased below approximately 1 mL O2/min kg. The GI tract had net lactate production at rest, but surprisingly switched to lactate uptake as cardiac output decreased. The mechanism of lactic acidosis was failure of hepatic lactate uptake to increase despite increased hepatic lactate delivery, as reported in adults subjects. However, in contrast, there was "true" hepatic dysfunction and lactate production only at the lowest levels of cardiac output, after onset of systemic lactate accumulation. Moreover, we speculate that tolerance of young lambs to hypoxia is at least due to two factors: 1) hepatic lactate uptake is maintained beyond the "critical" O2 delivery and fall in hepatic O2 consumption, and 2) there is a switch to lactate uptake by the GI tract serving to buffer the lactate.

Resuscitations are events that are often clouded by desperation and frenzy and directed by persons with limited experience, who may feel a great burden of responsibility for the circumstances preci...

To report longitudinal home recordings of hemoglobin O(2) saturation by pulse oximetry (Spo(2)) during unperturbed sleep in preterm and term infants.We recorded continuous pulse oximetry during the first 3 minutes of each hour of monitor use (nonevent epochs) for 103 preterm infants born at1750 g and ≤ 34 weeks postmenstrual age (PMA), and 99 healthy term infants.Median baseline Spo(2) was approximately 98% for both the preterm and term groups. Episodes of intermittent hypoxemia occurred in 74% of preterm and 62% of term infants. Among infants with intermittent hypoxemia, the number of seconds/hour of monitoring90% Spo(2) was initially significantly greater in the preterm than the term group and declined with age at a similar rate in both groups. The 75(th) to 95(th) percentiles for seconds/hour of Spo(2)90% in preterm infants were highest at 36 weeks PMA and progressively decreased until 44 weeks PMA, after which time they did not differ from term infants.Clinically inapparent intermittent hypoxemia occurs in epochs unperturbed by and temporally unrelated to apnea or bradycardia events, especially in preterm infants at 36 to 44 weeks PMA.

The recent study by Shipman et al1 is noteworthy, particularly given their focused examination of pediatric workforce data at the level of primary care service areas (PCSAs). As Shipman noted, although concerns regarding the number of primary care physicians have led to efforts to increase the number of trainees who elect careers in primary care, little has been done regarding the inequitable geographic distribution of the pediatric workforce. Although we agree that primary care for children across the United States may not be distributed equitably and support the need for further research in this area, some limitations can potentially threaten the interpretability of the results. The workforce numbers that are reported annually by the American Board of Pediatrics (ABP) differ from those presented in the article. The main reason for the difference is the database used …

Society for Pediatric Research Presidential Address 1993: Development of the Academic Pediatrician

We tested whether digoxin would limit tissue hypoxia during severe anemia by improving peripheral O2 distribution or decreasing O2 demands. Hematocrit (Hct) was reduced in eight control and eight digoxin-treated pigs from 27-28% to 17-18, 11-12, and 7-8%. Whole body and hindlimb blood flow, O2 transport, O2 extraction, and O2 consumption and serum catecholamines (epinephrine and norepinephrine) were determined at each Hct. Arterial and femoral venous lactate and O2 deficit were obtained to reflect tissue hypoxia. Cardiac output was significantly greater (P less than 0.05) with digoxin, as expected, but there were no differences in hindlimb blood flow. Also, whole body and hindlimb O2 extractions were equal in both groups for similar levels of O2 transport, suggesting that digoxin did not alter the relationship of O2 flow to metabolism in regional circulations. As whole body O2 consumption fell, controls accumulated more (P less than 0.05) O2 deficit and arterial lactate than the digoxin group. Furthermore, the slope demonstrating the linear increase of lactate with respect to O2 deficit was much steeper in controls (y = 1.11 + 0.06x) than in digoxin (y = 1.36 + 0.02x), suggesting that there were differences in the degree of tissue hypoxia for comparable O2 deficit. This may be attributed to the marked differences in catecholamine response: epinephrine was higher in controls at Hct of 7-8% and norepinephrine was higher at Hcts of 11-12 and 7-8%. Digoxin may have inhibited the release of catecholamine or reduced the stimulus for catecholamine secretion during anemia. We speculate that digoxin markedly improved the balance between peripheral O2 supply and demand during anemia by inhibiting catecholamine thermogenesis, thereby decreasing O2 demands. This may explain some of the salutary effects of glycosides in high-output cardiac failure with normal ventricular function.

Background As part of the Collaborative Home Infant Monitoring Evaluation, a home monitor was developed to record breathing, heart rate, other physiologic variables, and the time the monitor was used. Objective To determine the frequency of monitor use, factors that influence use, and validity of a model developed to predict use. Design We developed a model to predict monitor use using multiple linear regression analysis; we then tested the validity of this model to predict adherence for the first week of monitoring and for the subsequent 4-week period (weeks 2-5). Setting Clinical research centers in Chicago, Ill; Cleveland, Ohio; Honolulu, Hawaii; Los Angeles, Calif; and Toledo, Ohio. Patients Preterm infants, infants younger than 1 month with a history of autopsy-confirmed sudden infant death syndrome in a sibling, and infants with an idiopathic apparent life-threatening event were divided into 2 cohorts based on enrollment date. Main Outcome Measure Mean hours of monitor use per week. Results In cohort 1, the variables available before monitoring were only weakly associated with total hours of monitor use in weeks 2 to 5 (total model r 2 = 0.08). However, when hours of monitor use in week 1 were included as a variable to predict monitor use in weeks 2 to 5, the r 2 increased to 0.64 for hours of monitor use per week. Conclusions Our data show that monitor use in the first week was the most important variable for predicting subsequent monitor use. The study suggests that a major focus of home monitoring should be adherence in the first week, although it remains to be tested whether this adherence can be altered.