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Biomedical subjects

J Groswasser

Publications and source records attributed to J Groswasser.

32 records · Page 2Linked to original sources
PubMed1997

Development of cardiopulmonary integration and the role of arousability from sleep.

The recent literature on cardiopulmonary integration in infants is surveyed here, focusing on arousals from sleep. Recent studies reported that the ontogenicity of cardiopulmonary integration cannot be evaluated independently from that of sleep-wake cycles. The issue is of importance for researchers and clinicians evaluating cardiorespiratory characteristics in infants. It also has significant implications in the understanding of clinical conditions, such as parasomnias, obstructive sleep apneas, or some cases of sudden infant death syndrome. The propensity to arouse can be evaluated by exposing the sleeper to awakening challenges. Arousal thresholds are determined by measuring the intensity of the stimulus needed to induce arousals. However, these studies are complicated by factors such as the scoring of the arousal responses. Another difficulty lies in the choice and modality of the arousal stimulus. Noise, gases, light, and nociceptive, mechanical, chemical, or temperature stimuli have all been used to induce arousals. Confounding factors modify the sleeper's responses to a given stimulus. Prenatal drug, alcohol, or cigarette use and the infant's age or, previous sleep deprivation also modify thresholds. Other confounding factors include time of the night, sleep stages, the sleeper's body position, and sleeping conditions. Arousal can also occur spontaneously because of endogenous stimuli. The literature surveyed here also covers such unresolved issues as the clinical significance of aborted arousals, or the mechanisms responsible for the arousal reactions.

Age Factors↗
PubMed1996

Normal sleep architecture in infants and children.

Because the collection of normative sleep data in the pediatric age group largely depends on technical issues, this article discusses various aspects of sleep recordings in infants and children. Polygraphic monitoring of sleep and waking behavior contributes to a better description of maturational stages in children, from the prenatal period to the end of adolescence. This article reviews the general characteristics of normal children's sleep and the environmental factors that influence these maturational processes. The use of polygraphic recordings to identify neurological deficits and to predict behavioral and neurological outcome in infants and children, however, does not hold great promise. The importance of polysomnographic evaluation is admitted for some major clinical conditions, such as risks for abnormal breathing or narcoleptic attacks.

Adolescent↗
PubMed1996

Decreased cardiac responses to auditory stimulation during prone sleep.

OBJECTIVE: To evaluate the relationship between body position during sleep and the infants' cardiac responses to auditory stimulation. METHODS: Thirty healthy infants with a median age of 11 weeks were studied polygraphically for one night, while sleeping successively prone and supine, or vice versa. Their behavioral and cardiac responses were recorded during rapid eye movement (REM) sleep, both before and after exposure to 90 dB (A) of white-noise. RESULTS: Ten infants were excluded from the study, because they woke up during the challenge. For the 20 infants included in the analysis, no significant difference was seen between the prone and the supine position for total sleep time, sleep efficiency, percent of REM and nonrapid eye movement sleep, number of gross body movements, transcutaneous oxygen saturation levels, mean cardiac rate, heart rate variability, number of heart rate drops; mean respiratory rate, and number or duration of central or obstructive apneas. Auditory challenges induced significantly less overall changes in heart rate, less heart rate drops, less heart rate variability, as well as fewer and shorter central apneas in the prone than in the supine position. Autoregressive power spectral analysis of the heart rate was consistent with a possible increase in orthosympathetic tone in the prone position. CONCLUSION: Prone sleeping was associated with a decrease in cardiac responses to auditory stimulation and a possible increase in orthosympathetic activity. Prone positioning could favor a reduced reactivity to danger-signaling stimuli during REM sleep.

Acoustic Stimulation↗
PubMed1995

Reduction in obstructive breathing events during body rocking: a controlled polygraphic study in preterm and full-term infants.

OBJECTIVE: To investigate the effect of body rocking on infant respiratory behavior during sleep. METHODS: Eighteen infants with documented obstructive sleep apneas were studied. There were eight premature infants with persistent bradycardias and 10 infants born full-term, admitted after an idiopathic apparent life-threatening event. No cause for the obstructive apneas was found. The infants were recorded with polygraphic techniques during two successive nights. They were randomly assigned to a rocking or a nonrocking mattress. The conditions were reversed the following night, in a crossover design. RESULTS: In both groups of infants, no significant difference was seen between the two consecutive nights for most of the variables studied: total sleep time, the proportion of non-rapid-eye-movement and rapid-eye-movement sleep, the number of arousals, the number and maximal duration of central apneas, the frequency of periodic breathing, the level of oxygen saturation, and heart rate. During the nonrocking nights, all infants had repeated obstructive breathing events. In seven of the eight preterm infants and in nine of the 10 full-term subjects, body rocking was associated with a significant decrease in the frequency of obstructive events. During rocking, in the preterm infants the obstructions fell from a median of 2.5 to 1.8 episodes per hour (P = .034). In the full-term infants, rocking reduced the obstructive events from a median of 1.5 obstructions per hour to 0.7 (P = .005). No difference was seen for the duration of the obstructive episodes. CONCLUSION: In preterm and full-term infants prone to obstructive sleep apneas, gentle side-to-side body rocking is associated with a significant decrease in the frequency of upper-airway obstructions.

Beds↗
PubMed1994

Mechanisms of obstructive sleep apneas in infants.

During sleep, infants with obstructive sleep apneas are characterised by snoring, laborious breathing, and profuse sweating. During wakefulness, they may have breath-holding spells, and during feeding, difficult breathing and swallowing coordination. Abnormal weight, difficult growth, and recurring ear infections may also develop. During sleep apneas, cinefluoroscopy shows approximation of tongue and hypopharyngeal tissues, with an obliteration of the air space. The obstructed breaths occur mainly in REM, and light NREM sleep, associated with total short sleep time, and frequent arousals. Preterm infants, and term neonates are more prone to obstructive apneas than older healthy infants. Apneas are more frequently seen in boys and in case of excess in body weight. Obstructive apneas are frequently associated with upper airway anatomic abnormalities: malformations, soft tissue infiltration, and neurologic lesions impairing muscle contractions. Alterations of the autonomic nervous control may induce airways obstructions. Contributing factors include mucopolysaccharide storage disease, hypothyroidism, or Down's syndrome. Superimposed factors may occur, such as nasal obstruction, secretions in the airways, or tissue edema. Pressure- and chemo-sensitive reflexes may also favor obstruction. Environmental factors also contribute to the development of sleep apneas: body position, neck flexion, sleep deprivation, or the effects of sedative drugs.

Airway Resistance↗
PubMed1994

Polygraphic evaluation of night-to-night variability in sleep characteristics and apneas in infants.

The study was designed to evaluate whether results of a single overnight recording session are sufficient for the study of sleep profiles and detection of apneas in infants, or whether it would be beneficial to extend the recording period. Nineteen infants were recorded during successive nights. Eight of the 19 infants were studied after an idiopathic apparent life-threatening event, whereas the other 11 were healthy. There were 13 boys and six girls, with a median age of 11 weeks (range 5-36 weeks). All infants were recorded polygraphically during 2 nights, and 11 were recorded during 3 successive nights. No significant difference was observed between any of the following variables, regardless of the number of nights for which the recording was performed: total recording time, total sleep time, delay in sleep onset, time awake, percent of rapid eye movement or nonrapid eye movement sleep, mean respiratory rates, density and duration of central, obstructive or mixed apneas. The frequency of obstructed breathing events for each infant did not differ significantly from 1 night to the next. The present study indicates that under adequate study conditions, recordings of a single night can reliably describe the frequency of central and obstructive apneas in infants.

Arousal↗
PubMed1994

Prenatal exposure to cigarettes in infants with obstructive sleep apneas.

OBJECTIVE: To investigate the effect of prenatal smoking on infant respiratory behavior during sleep. METHODS: A questionnaire concerning family habits and infants' history was completed for 550 healthy infants before a 9-hour night polysomnographic study. Because the data for 41 infants were not available for analysis, 509 subjects were studied: 115 were newborns evaluated within 1 week after birth, and 394 were healthy infants admitted at 11 weeks of life (range 5 to 29 weeks) after various research protocols. RESULTS: According to the smoking frequency of the mothers during pregnancy, the subjects were defined as "nonsmokers" (no cigarette smoked during pregnancy; n = 400), "light smokers" (1 to 9 cigarettes per day; n = 37), or "smokers" (10 or more cigarettes per day; n = 72). Compared with nonsmokers and light smokers, "smoking" mothers had a significant increase in the number of episodes of uterine bleeding during the pregnancy. Their infants had lower birth weights and more frequent episodes of profuse sweating during sleep. Infants of smokers also had more frequent and longer obstructive sleep apneas than those of the two other groups. For infants of smokers the relative risk for obstructive apneas was 2.76 (95% confidence interval: 1.63 to 4.69; P = .001). The relation between prenatal smoking and postnatal manifestation of obstructive sleep apneas demonstrated a dose-response pattern. Paternal smoking during pregnancy increased the risk of obstructive apneas only in the infants of smoking mothers, but not in those of the two other groups. Maternal smoking after birth did not add significantly to the risk of obstructive apneas. The effect of smoking was seen in older infants, as well as in the newborn not yet exposed to ambient cigarette smoke. A stepwise logistic regression, using obstructive sleep apneas as the dependent variable identified three significant independent variables: smoking during pregnancy (P = .001), profuse sweating during sleep (P = .001), and birth weight (P = .010). No explanation was found for the effect of prenatal smoking on obstructive sleep apneas. CONCLUSION: Prenatal smoking by mothers correlated with an increase in frequency and length of obstructive apneas and a decrease in birth weight of their infants. The infants were under greater risk for obstructive apnea if both parents smoked. Explanations for our results are unknown to us, but these findings may be of interest in the study of infant breathing behavior and epidemiological characteristics of sudden infant death syndrome.

Adolescent↗
PubMed1993

Clinical symptoms associated with brief obstructive sleep apnea in normal infants.

Relatively little data exist concerning the manifestations of repeated obstructive sleep apnea in normal infants. A questionnaire concerning daytime and sleep habits was completed by the parents of 4,100 healthy infants before they underwent a 9-hour night monitoring study. One hundred infants with an obstructive apnea index above 1.2 were randomly selected. They formed the "apnea" group. From the initial population, 300 infants with no apnea were also selected to form the "no-apnea" group. Both groups were matched for sex, gestational age, post conceptional age, birth weight, mother's age, parity and a family history of sudden infant death. Five variables from the questionnaires significantly differentiated the two groups of infants. When awake, the infants with apnea were characterized by a greater frequency of breathholding spells (22% of apnea infants) and episodes of fatigue during feeding (28%) than the non-apnea infants. During sleep, they exhibited a greater frequency of profuse sweating (15%), snoring (26%) or noisy breathing (44%). Multiple symptoms were present in some infants. A stepwise logistic regression resulted in two significant independent variables: profuse sweating during sleep (p = 0.008) and noisy breathing (p = 0.002). The predictive value of these two symptoms was tested on a new group of 650 healthy infants. The two independent variables led to the correct classification of 60 of the 67 infants with apnea (89.67%) and 382 of the 583 non-apnea infants (65.5%). A positive history alone had a positive predictive value of 0.21.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography↗
PubMed1993

Prone or supine body position and sleep characteristics in infants.

OBJECTIVE: To evaluate the potential relation between body position and sleep characteristics in normal infants. PATIENTS: Two groups of 3-month-old healthy infants were evaluated: 40 infants who usually slept supine, and 40 who usually slept prone. The two groups were matched for gender, gestational age, postnatal age, birth weight, and total recording time. RECORDING TECHNIQUES: The 80 infants were studied polygraphically during one night in the pediatric sleep laboratory. They were allowed to fall asleep in their usual sleep position, and every 3 hours were gently turned from prone to supine, or from supine to prone. RESULTS: In each group, 6 infants were excluded from the analysis, because they woke up after having been turned over. In both groups, no significant difference was seen between the prone and the supine body positions for the following variables: number of sleep state changes; number of gross body movements; percent of rapid eye movement sleep; saturation with oxygen, arterial blood levels; number and duration of acid esophageal reflux; rectal temperature; mean respiratory rates; water evaporation rates from the forehead skin; and number or duration of central or of obstructive apneas. In both groups of infants, prone body position was associated with a significant increase in sleep duration (+16%) and in non-rapid eye movement sleep (+25%) and a significant decrease in number of arousals (-40%) and in their duration (-43%). CONCLUSIONS: No explanation has been found for the sleep-promoting effect of prone body positioning. The finding could be of interest to the study of infants' sleep quality, as well as to the potential relation between body positions and sudden death during sleep.

Female↗
PubMed1992

Sleep and cardiorespiratory characteristics of infant victims of sudden death: a prospective case-control study.

We studied the polygraphic sleep recordings of 30 infants who eventually died of sudden infant death syndrome (SIDS) and those of 60 matched control infants. All records were extracted from 20,750 sleep studies collected prospectively in 10 sleep laboratories. Of the 30 future SIDS victims, 5 were siblings of SIDS victims and 9 were studied after an apparent life-threatening event. For each SIDS victim, two normal control infants were matched for sex, gestational age, postnatal age and weight at birth. The future SIDS infants were reported to have more frequent episodes of regurgitations after feeding (p = 0.01) and profuse sweating during sleep (p = 0.01) than the control subjects. Only two polysomnographic variables characterized the future SIDS infants. Compared to control subjects, the SIDS infants moved less during sleep (p = 0.04) and had significantly more frequent obstructed breathing events. Obstructive and mixed apneas were seen in 23 of 30 future SIDS victims, but in only 9 of 60 control subjects (p = 0.01). The obstructed and mixed apneas lasted longer in the SIDS than in the control infants (p = 0.01) but did not exceed 15 seconds. The obstructed breaths occurred mainly in rapid eye movement sleep (78% of the events) and were accompanied by drops in heart rates to 68 beats per minute and in SaO2 levels to 75%. The present report adds further indirect evidence for a possible sleep-related impairment of respiratory control in some infants who eventually died of SIDS.

Case-Control Studies↗