Risk Of Sudden Infant Death Research Articles

Sudden infant death syndrome and maternal smoking

A number of socioeconomic and demographic factors are associated with an increased risk ofsudden infant death syndrome (SIDS), but few readily amenable exposure factors have been identified.1 Reports of an association between maternal cigarette smoking during pregnancy and the subsequent occurrence of SIDS, however, do offer the possibility that reducing maternal smoking could result in a decline in the SIDS rate.2-4 Whether the association between SIDS and a history of maternal smoking during pregnancy is biological in nature or a proxy for maternal behavior is not clear. Haglund and Cnattingius reported that infants born to women who smoke during pregnancy die earlier with SIDS than infants of nonsmokers and that a doseresponse association exists between maternal smoking and the risk of SIDS.5 Their report supports the plausibility of a biological mechanism. We attempted to confirm their observations in two large US data sets.

Sudden infant death syndrome: does winter affect poor and rich babies equally?

The aim was to investigate whether the winter increase in risk of sudden infant death was similar across social classes. This was an unmatched case-control study using routine data. Cases and controls were selected from files holding routine birth and death certificate data for England and Wales for 1986. Cases were deaths in the first year of life occurring in the summer or the winter of 1986 with mention of sudden infant death or SIDS in the death certificate. Controls were a 1% random sample of all children born in the same year. Only children whose parents were married or living together at the time of birth registration were included. Data on age and season of death for cases, and on date of birth, social class of father, and birth weight were abstracted from the file. Season of birth and birth weight were treated as confounding variables. The increase in risk of SIDS in winter was calculated for each age group and social class. The winter increase in SIDS was more marked among the higher social classes for all ages, but not to a statistically significant degree: the p values for heterogeneity were 0.26 for age 0-3 months, 0.42 for 4-7 months, and 0.41 for 8-12 months. There is no direct association between seasonal variation in sudden infant death and social class.

Empfehlungen zur ambulanten Diagnostik schlafbezogener Atemstörungen in der Pädiatrie

In ambulatory monitoring of sleep related breathing disorders (SRBD) during infancy and childhood developmental differences in causes and in diagnsotic measures as well as social conditions should be considered. SRBD often precede nonrespiratory diseases such as infections, metabolic disorders, seizures or malformations. In infancy, breathing disorders of prematurity and the apparently life-threatening event (ALTE), belonging to the group with increased risk for sudden infant death (SIDS), play an important role. Obstructive sleep-apnea-syndrome is found in infants with malformations and rather often from the second year on, in children showing tonsillar or adenoidal hypertrophy. Abnormal ECG, transcutaneous pO2 < 50 mmHg, pCO2 > 50 mmHg, SaO2 < 87% are valuable indicators, since apneas may be missing. Specified ambulatory monitors for infants are missing. For this reason systems for adults, with continuous recording of heart rate, respiration with impedance and nasal flow, and oxygen saturation, may be used. Infants need personal supervision during ambulatory monitoring.

The risk of sudden infant death from gastroesophageal reflux

Gastroesophageal reflux (GER) has been a suspected cause of infant deaths and sudden infant death syndrome (SIDS). We examined our 10-year experience with 499 consecutive infants 6 months of age or less who had extended (18 to 24 hours) esophageal pH monitoring performed to evaluate for GER. The data extracted from the esophageal pH records included the pH score, the pattern of GER (type I, II, or III), and the mean duration of reflux during sleep (ZMD). All infants were followed to determine the occurrence and cause of death during the first year of life. Of the 19 deaths found in the series, three were classified as SIDS and two were in-hospital deaths caused by reflux-induced aspiration. All five of these infants who died had a prolonged ZMD (> 3.8 minutes) and received either basic medical (n = 4) or no (n = 1) antireflux therapy. Four infants also had the type I pattern of GER. There was a 9.1% ( 4 44 ; 95% confidence limits, 2.5% to 21.7%) incidence of reflux-related or SIDS deaths in infants with type I GER and a prolonged ZMD who were treated nonoperatively, compared with none ( 0 83 , P = .03) in the same group of infants treated with antireflux surgery. The incidence of SIDS was higher in infants with type I GER and a prolonged ZMD who were treated nonoperatively ( 3 44 , 6.8%) compared with all other infants treated nonoperatively ( 0 265 , o%; P = .003). Infants with type I GER and a prolonged ZMD had a lower incidence of SIDS when treated with antireflux surgery ( 0 83 , 0%) than when treated nonoperatively ( 3 44 , 6.8%; P = .04). In conclusion, GER appears to be a significant cause of infant death and SIDS. Infants at the highest risk for death can be identified with extended esophageal pH monitoring and the definitive elimination of GER can prevent some SIDS deaths.

Home monitors for infants: use, misuse, and “over-the-counter” use

The prevalence of "over-the-counter" monitors, was surveyed in infants referred to five Belgian paediatric centres between September 1987 and March 1988 for evaluation of their risk for sudden infant death (SID). Questionnaires were collected from 1625 families. Of the infants, 8.9% were already being monitored at home. For 78.1% of the infants no medical advice had been solicited, and for 21.9%, a paediatrician or a general practitioner had advised home monitoring without previous evaluation. Forty of 824 infants referred with no history of SID, and no history of apparent life-threatening event (ALTE), were monitored (4.8%). Monitoring was started for 3.8% (5 out of 130) of the infants who had lost a cousin or an uncle to SID, and for 22.2% (69 of 310) of the younger siblings of a SID victim. Of the 341 infants who had presented with an ALTE, monitoring was started in 32 (9.4%). The infants were monitored with respiratory monitors only, and in 86% of the monitors, the alarm delay had been regulated unnecessarily low.

Changes of heart rate in college students in connection with examination situation

Objective: The risk of sudden infant death during sleep was postulated to decrease with the use of a pacifier and by conditions facilitating arousals from sleep. We evaluated the influence of a pacifier on arousal from sleep in healthy infants.Study design: Fifty-six healthy infants were studied with polygraphy during 1 night; 36 infants used a pacifier regularly during sleep, and 20 never used a pacifier. Thumb users or occasional pacifier users were not included in the study. The infants were recorded at a median age of 10 weeks (range 6 to 19 weeks). To evaluate auditory arousal thresholds, the infants were exposed to white noise of increasing intensity during rapid eye movement sleep.Results: Polygraphic arousals occurred at significantly lower auditory stimuli in pacifier users than in nonusers (P = .010). Compared with nonusers, pacifier users were more frequently bottle-fed than breast-fed (P = .036). Among infants sleeping without a pacifier, breast-fed infants had lower auditory thresholds than bottle-fed infants (P = .049).Conclusions: Infants using pacifiers during sleep had lower auditory arousal thresholds than those who did not use a pacifier during sleep. Breast-feeding could be a further factor contributing to lower arousal thresholds. These findings could be relevant to the occurrence of sudden infant deaths during sleep.

Vaccination and cot deaths in perspective.

In 1985 twin boys simultaneously succumbed to sudden unexpected deaths two to three hours after vaccination with diphtheria, tetanus, and pertussis vaccine (DTP). This occurrence again raises the question of whether an association of sudden infant death (SID) with vaccination is other than temporal. Taking the incidence of SID in conjunction with rates of infant vaccination in the United Kingdom, nine infants would be expected to die, each year by chance alone, suddenly within 24 hours of (and within each 24 hour period succeeding) vaccination with DTP. Twins are at a greater risk of SID than single born infants and occasionally are found dead together. A number of studies into DTP vaccination as a risk factor in SID have shown that SID is less common in vaccinated than in unvaccinated infants.

Multiple causes of asphyxia in infants at high risk for sudden infant death.

A wide range of clinical findings was present in 58 near-miss sudden infant death syndrome (SIDS) infants and 6 surviving twins of SIDS siblings. Specific investigations included: studies of gastro-oesophageal reflux and aspiration (24-hour oesophageal pH recordings, barium swallow, radionuclide 'milk-scan'); polygraphic studies of breathing, reflux, and sleep state; studies of upper airways disease (lateral airways radiography and endoscopy); detection of seizure activity by electroencephalography; evaluation of thiamine status by erythrocyte transketolase activity of venous blood. Thiamine deficiency was found in 12 of 43 tested infants; 5 of the deficient infants had a familial history of SIDS. Many potential mechanisms for asphyxia were found: idiopathic central apnoea (7 infants), tracheal obstruction from minimal tracheomalacia or aberrant innominate artery (4 infants), temporal lobe or generalised seizures (6 infants), gastro-oesophageal reflux (55 infants) with intrapulmonary aspiration (11 infants). The high incidence, severity, and timing of reflux were new findings. Reflux occurred in active and indeterminate sleep, but not in quiet sleep. The depression of respiratory reflexes by active sleep stresses the vulnerability to asphyxia. Two factors suggest that near-miss episodes are related to SIDS: the similar age distribution but earlier occurrence of near-miss episodes compared with age at death of SIDS infants, and the subsequent sudden death of 2 infants whose necropsies were consistent with SIDS.

Respiratory pauses and apnea during daytime sleep in normal infants during the first year of life: Longitudinal observations

Respiratory pauses (3–10 sec in duration), apnea (>10 sec in duration), and periodic respiration observed in thoracic respirograms were measured in 226 polysomnograms obtained on 17 normal infants during the first year of life. All subjects had one or more respiratory pauses in a majority of recordings; 35% had respiratory pauses in all recordings; 75% of respiratory pauses were associated with body movement. There is marked intersubject and even intrasubject variability in respiratory pause rates. The range of mean respiratory pause rates among subjects was 2.0–14.4/h, and for single recordings was 0.0–43.6/h. Their occurrence was directly related to the occurrence of periodic respiration. Rates were higher during REM and indeterminate sleep than during slow wave sleep. There was no significant trend toward increase or decrease in respiratory pause rate during the first year post term. Apnea occurred in only one of the 226 recordings (0.4%). Periodic respiration occurred in 8 of 17 subjects (47%), and in 25 of 226 recordings (11%). Its occurrence was unrelated to sleep stage. The following conclusions are considered valid on the basis of the data presented and reports in the literature: (1) Rates of respiratory interruption are higher before than after 40 weeks conceptional age. (2) There is considerable intersubject variability in rates of respiratory interruptions. (3) Respiratory pauses are common during sleep in normal human infants. (4) Respiratory pauses occur more frequently with movements than in their absence. (5) Respiratory pause rates are higher during REM sleep than during slow wave sleep. (6) Apneas of greater than 10–15 sec duration do occur in normal infants, but are rare. From the clinical viewpoint, respiratory pauses (<15 sec) of the central type, regardless of abundance, and periodic respiration cannot by themselves be used as evidence that a baby is at risk of anything. The occurrence of apneas (>15 sec duration), especially if any are of the obstructive or mixed types (and perhaps respiratory pauses of the obstructive and mixed types), and/or if associated with bradycardia or decrease in oxygen saturation, indicate sleep apnea syndrome and suggest risk of sudden infant death.