Why do ALTE infants not die in SIDS?

Aim: To compare known risk factors for sudden infant death syndrome (SIDS) amongst infants with apparent life threatening events (ALTE) with their matched controls, and ALTE infants who subsequently died of SIDS with infants surviving an ALTE.
Methods: Questionnaires with replies were obtained from 58 ALTE infants and 56 sex and age matched ALTE control infants. 244 SIDS cases and 868 SIDS controls were used as comparison.
Results: The incidence of ALTE was found to be 1.9% among SIDS controls, but 7.4% among infants who later on died of SIDS. The parents sought medical advice in 0.9% vs 3.7%. ALTE infants did not differ from their matched controls. In the ALTE group 13.3% of the survivors had the combination of prone sleeping and maternal smoking compared with 33.3% of those who became SIDS victims.
Conclusions: Our results show some major differences between the ALTE infants and SIDS victims not supporting that these conditions belong to the same entity. However, we cannot exclude the possibility that there is a subpopulation of ALTE infants who did not die in SIDS due to that they were sleeping on the back and not exposed to nicotine.     

Obstructive sleep apnea in infants: relation to family history of sudden infant death syndrome, apparent life-threatening events, and obstructive sleep apnea

OBJECTIVES: Familial aggregation of obstructive sleep apnea (OSA) has been shown to be associated with sudden infant death syndrome (SIDS) and apparent life-threatening events (ALTE) in infants. We wanted to determine the incidence of OSA in infants with siblings with ALTE and SIDS referred to our sleep clinic and to ascertain whether OSA was more common in infants who have family histories of SIDS, ALTE, and OSA. STUDY DESIGN: We studied 125 infants (mean age, 11.5 +/- 0.6 weeks) who were separated into 2 groups on the basis of their family history; polysomnographic studies were performed on each infant. RESULTS: Twenty infants had a multiple family history of SIDS, ALTE, or OSA (group 1), whereas the other 105 infants (group 2) had only one case of SIDS or ALTE within the family and no known history of OSA. We found that 19 of 20 infants in group 1 had OSA, whereas only 31 of 105 infants in group 2 had OSA (chi-squared analysis, P <.05). The OSA recorded was more frequent in infants of group 1 than in those of group 2. Follow-up studies in some infants with OSA demonstrated a progressive decrease in OSA, which resolved between 6 and 12 months of age. CONCLUSION: We conclude that infants of families with multiple histories of SIDS, ALTE, and OSA are more likely to have OSA than infants of families with only one case of SIDS or ALTE.     

Metabolic disease in 10 patients with sudden unexpected death in infancy or acute life‐threatening events

In order to determine the associations between sudden unexpected death in infancy (SUDI) or acute life‐threatening events (ALTE) and inborn errors of metabolism, particularly organic acidemia and fatty acid oxidation disorders, we evaluated clinical features in patients with SUDI or ALTE. The subjects were infants between the ages of 7 days and 3 years who developed SUDI or ALTE between January 2004 and December 2013. They were then diagnosed as having inborn errors of metabolism on gas chromatography–mass spectrometry (GC/MS) and/or tandem mass spectrometry (MS/MS). The age distribution, onset forms, and clinical findings were evaluated during the acute phase. Inborn errors of metabolism were detected in three of 196 patients with SUDI, and in seven of 167 patients with ALTE. Of these 10 patients, nine had a history of poor feeding and somnolence during the neonatal period, and symptoms of infection such as cough, fever or vomiting during infancy. Routine laboratory tests during an acute phase indicated hyperammonemia, liver dysfunction, increased blood creatine kinase, acidosis, positive ketone bodies in urine or blood, or hypoglycemia. When SUDI or ALTE are encountered in the emergency unit, it is essential that a detailed medical history is taken, particularly with regard to the neonatal period, and that specific abnormalities are investigated on routine laboratory tests. Moreover, samples such as urine, serum, and filter paper blood specimens should be collected for GC/MS and/or MS/MS of organic acids and acylcarnitines, to identify inborn metabolic disorders.     

Increased cerebrospinal fluid beta-endorphin immunoreactivity in infants with apnea and in siblings of victims of sudden infant death syndrome

To gain further insight into the possible role of endogenous opioid peptides in the respiratory difficulties associated with the apnea of infancy and other disorders possibly related to apnea, the levels of beta-endorphin immunoreactivity were measured in the cerebrospinal fluid (CSF) of five groups of infants: (1) infants with proved apnea, (2) infants with histories of an apparent life-threatening event (ALTE), (3) siblings of victims of the sudden infant death syndrome (SIDS), (4) infants with suspected but unproved apnea, and (5) infants undergoing investigation for other acute illnesses. Twenty-two infants considered at risk for an ALTE (groups 1 to 3) had significantly higher CSF beta-endorphin equivalents (88 +/- 7 pg/mL) than did the 22 control patients in groups 4 and 5 (31 +/- 3 pg/mL). Plasma beta-endorphin immunoreactivity, which was also measured in some of the infants, did not correlate with levels in CSF and, in fact, was significantly lower in the groups at risk for an ALTE (50 +/- 9 pg/mL; n = 14) than in the control subjects (80 +/- 6 pg/mL; n = 11). These studies indicate that elevated beta-endorphin immunoreactivity in CSF may be a marker in infants who have apnea and who may be considered at risk for an ALTE.     

A clinical comparison of SIDS and explained sudden infant deaths: how healthy and how normal?

OBJECTIVES—To compare the clinical characteristics associated with sudden infant death syndrome (SIDS) and explained sudden unexpected deaths in infancy (SUDI).
DESIGN—Three year population based, case control study with parental interviews for each death and four age matched controls.
SETTING—Five regions in England (population, > 17 million; live births, > 470 000).
SUBJECTS—SIDS: 325 infants; explained SUDI: 72 infants; controls: 1588infants.
RESULTS—In the univariate analysis, all the clinical features and health markers at birth, after discharge from hospital, during life, and shortly before death, significant among the infants with SIDS were in the same direction among the infants who died of explained SUDI. In the multivariate analysis, at least one apparent life threatening event had been experienced by more of the infants who died than in controls (SIDS: 12% v 3% controls; odds ratio (OR) = 2.55; 95% confidence interval (CI), 1.02 to 6.41; explained SUDI: 15% v 4% controls; OR = 16.81; 95% CI, 2.52 to 112.30). Using a retrospective illness scoring system based on "Baby Check", both index groups showed significant markers of illness in the last 24 hours (SIDS: 22% v 8% controls; OR = 4.17; 95% CI, 1.88to 9.24; explained SUDI: 49% v 8% controls; OR = 31.20; 95% CI, 6.93 to 140.5).
CONCLUSIONS—The clinical characteristics of SIDS and explained SUDI are similar. Baby Check might help identify seriously ill babies at risk of sudden death, particularly in high risk infants.
     

Gastric secretion in infants. Application to the study of sudden infant death syndrome and apparently life-threatening events.

Sudden infant death is a problem of paediatric public health which remains an unpredictable phenomenon of unknown aetiology. Many authors have discussed the role of a neurovegetative aetiology, the role of the vagus nerve being suspected above all. A biological approach to vagal tone was attempted by assaying intragastric pepsin and serum pepsinogen and calculating the ratio of pepsin to acid in control infants, and by assaying serum pepsinogen levels in infants having suffered an apparently life-threatening event (ALTE) or who died of the sudden infant death syndrome (SIDS). This study showed that the age of 2 months appears to be a turning point in the development of digestive secretions, an age when the risk of SIDS is at its peak, and that the rates of the selected biological markers are significantly higher in victims of SIDS or ALTE than in controls. The predictive value of these biological markers is currently under evaluation.     

Epidemiology of apparent life threatening events

Aims: To investigate the epidemiology and risk factors of apparent life threatening events (ALTE). Methods: A prospective study enrolled all live-born infants in the Tyrol (1993–2001). Information on pregnancy, sociodemographic characteristics, child care practices, and infant''s behaviour in the first four to six weeks of life was collected with a standardised questionnaire, and was available for 44 184 infants. ALTE was identified from hospital admission records. Results: During the study period 164 ALTE cases were identified, corresponding to an incidence of 2.46/1000 live births. In 73 of these infants no cause for the event and no comorbidity could be found (idiopathic ALTE). On average ALTE manifested ten weeks earlier than SIDS. Of various SIDS risk factors in the survey area, the prone sleeping position, smoking during pregnancy, low gestational age, profuse night sweating, and family history of infant death showed a moderate relation to the risk of overall ALTE, but only smoking maintained significance in the multivariate risk model. None of these variables was associated with idiopathic ALTE. In contrast to SIDS the frequency of ALTE did not change during the study period. None of the ALTE infants experienced SIDS later in life. Behavioural abnormalities such as feeding difficulties, episodes of pallor, cyanotic episodes, and repeated apnoea episodes were strongly associated with an increased risk of overall and idiopathic ALTE. Conclusions: Although there are some similarities in the clinical presentation and epidemiology of SIDS and ALTE, differences clearly predominate. Accordingly, ALTE and SIDS should not be considered different manifestations of the same disease process.     

Do risk factors differ between explained sudden unexpected death in infancy and sudden infant death syndrome?

BACKGROUND: In Germany, 2910 infants died in 2004; for many infants the reason was clear, especially prematurity or congenital abnormalities. However, 394 babies die every year suddenly and unexpectedly. The cause may be immediately clear, but is often not obvious. AIMS: (1) To describe the causes of explained sudden unexpected death in infancy (SUDI) and (2) to compare risk factors for sudden infant death syndrome (SIDS) and explained SUDI. METHODS: A 3-year population-based case-control study in Germany, 1998-2001. RESULTS: 455 deaths, of which 51 (11.2%) were explained. Most of these deaths were due to respiratory or generalised infections. The risk factors for SIDS and explained SUDI were remarkably similar except for sleep position and breast feeding. Prone sleeping position is a major risk factor for SIDS (adjusted odds ratio (OR) 7.16, 95% confidence interval (CI) 3.85 to 13.31) but not for explained SUDI (adjusted OR 1.71, 95% CI 0.25 to 11.57). Not being breast fed in the first 2 weeks of life is a risk factor for SIDS (adjusted OR 2.37, 95% CI 1.46 to 3.84) but not for explained SUDI (adjusted OR 0.39, 95% CI 0.08 to 1.83). CONCLUSIONS: Prone sleeping position is a unique risk factor for SIDS. Socioeconomic disadvantage and maternal smoking are risk factors for both SIDS and explained SUDI, and provide an opportunity for targeted intervention.     

Sudden unexpected death in infancy: A historical perspective

Epidemiological, developmental and pathological research over the last 40 years has done much to unravel the enigma of sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS) that has afflicted the human condition for millennia. Modifications in infant care practices based on the avoidance of risk factors identified from a consistent epidemiological profile across time and multiple locations have resulted in dramatic reductions in the incidence of SUDI and SIDS in particular. The definition of SIDS (or unexplained SUDI) has been continually refined allowing enhanced multidisciplinary research, results of which can be more reliably compared between investigators. These latter expanded definitions mandating death scene investigations, evaluation of the circumstances of death and more comprehensive autopsies including additional ancillary testing have illuminated the importance of life‐threatening sleep environments. The triple‐risk hypothesis for SIDS has been increasingly validated and formulates an inextricable relationship between an infant's state of development, underlying pathological vulnerability and an unsafe sleep environment for sudden infant death to occur. Today, the major risk factors for SUDI are maternal smoking and bed sharing, and the challenge is to implement effective strategies that will reduce the exposure to such risks as was done with prone sleeping position. The challenges ahead include development of clinical methods and/or laboratory testing that will accurately identify which infants are at particularly high risk of SIDS but also means by which their deaths can be prevented.     

Autopsy findings of co-sleeping-associated sudden unexpected deaths in infancy: relationship between pathological features and asphyxial mode of death

Aim: Co‐sleeping is associated with increased risk of sudden unexpected death in infancy (SUDI)/sudden infant death syndrome (SIDS). The aim of this study is to examine autopsy findings from a single UK specialist centre to determine the relationship between co‐sleeping and cause of death. Methods: Retrospective analysis of >1500 paediatric autopsies carried out by paediatric pathologists over a 10‐year period. SUDI was defined as sudden unexpected death of an infant aged 7–365 days; deaths were categorised into explained SUDI (cause of death was determined) and unexplained SUDI (equivalent to SIDS). Results: There were 546 SUDI; sleeping arrangements were specifically recorded in 314; of these, 174 (55%) were co‐sleeping‐associated deaths. Almost two thirds (59%) of unexplained SUDI were co‐sleeping compared to 44% explained SUDI (95% confidence interval (CI) 1.0–27.2%, P= 0.03); however, this difference remained statistically significant only for the first 5 months of life (95% CI 3.5–33.2%, P= 0.01). In unexplained SUDI aged < 6 months, there were no significant differences between co‐sleeping and non‐co‐sleeping deaths with respect to ante‐mortem symptoms, intrathoracic petechiae, macroscopic lung appearances, pulmonary haemosiderin‐laden macrophages, and isolation of specific bacterial pathogens; however, fresh intra‐alveolar haemorrhage was reported more commonly in co‐sleeping (54%) than in those that were not (38%; 95% CI 1.4–30.5%, P= 0.03). Conclusions: Co‐sleeping is associated with unexplained SUDI/SIDS in infants aged < 6 months, suggesting that co‐sleeping is related to the pathogenesis of death in younger infants. The finding that intra‐alveolar haemorrhage is more common in co‐sleeping suggests that a minority of co‐sleeping‐associated deaths may be related to an asphyxial process.     

Epidemiology of apparent life threatening events.

AIMS: To investigate the epidemiology and risk factors of apparent life threatening events (ALTE). METHODS: A prospective study enrolled all live-born infants in the Tyrol (1993-2001). Information on pregnancy, sociodemographic characteristics, child care practices, and infant's behaviour in the first four to six weeks of life was collected with a standardised questionnaire, and was available for 44,184 infants. ALTE was identified from hospital admission records. RESULTS: During the study period 164 ALTE cases were identified, corresponding to an incidence of 2.46/1000 live births. In 73 of these infants no cause for the event and no comorbidity could be found (idiopathic ALTE). On average ALTE manifested ten weeks earlier than SIDS. Of various SIDS risk factors in the survey area, the prone sleeping position, smoking during pregnancy, low gestational age, profuse night sweating, and family history of infant death showed a moderate relation to the risk of overall ALTE, but only smoking maintained significance in the multivariate risk model. None of these variables was associated with idiopathic ALTE. In contrast to SIDS the frequency of ALTE did not change during the study period. None of the ALTE infants experienced SIDS later in life. Behavioural abnormalities such as feeding difficulties, episodes of pallor, cyanotic episodes, and repeated apnoea episodes were strongly associated with an increased risk of overall and idiopathic ALTE. CONCLUSIONS: Although there are some similarities in the clinical presentation and epidemiology of SIDS and ALTE, differences clearly predominate. Accordingly, ALTE and SIDS should not be considered different manifestations of the same disease process.     

Parental compliance with home cardiorespiratory monitoring

AIMS—To evaluate parental compliance with home cardiorespiratory monitoring of premature infants with apnoea, siblings of infants who died of sudden infant death syndrome (SIDS), and infants with an apparent life threatening event (ALTE), during the first month of use.METHODS—A retrospective review of the first month''s recordings was conducted on 39 premature infants with apnoea, 13 siblings of SIDS, and 16 infants with ALTE. All infants were singletons. Recommendations during the study period (1992-1994) were for daily use for 23hours per day. Measurements were average daily hours of use and consistency of use (daily or variable). Gestational age, maternal age, and socioeconomic status as measured by receipt of public assistance were also recorded.RESULTS—Siblings of SIDS were monitored for fewer hours than were premature or ALTE infants. Only 54% of sibings of SIDS were monitored daily, compared to 87% of premature infants and 93% of ALTEs. Within each diagnostic category socioeconomic status did not affect average hours of monitoring. Consistency of use was more evident in those with private insurance, although the trend did not reach significance.CONCLUSIONS—Parents of infants with apnoea of prematurity or ALTE are highly compliant with cardiorespiratory monitoring recommendations in the first month of monitor usage. Siblings of SIDS are monitored for fewer hours and are less likely to be monitored on a daily basis.     

Size for gestational age at birth: impact on risk for sudden infant death and other causes of death, USA 2002

Background

Small for gestational age (SGA) infants have been reported to be at higher risk for sudden infant death syndrome (SIDS).

Objective

To compare the risk of SIDS among SGA and large for gestational age (LGA) infants with that of death from other causes of sudden unexpected deaths in infancy (SUDI) and the residual “other” causes of infant death.

Methods

The 2002 US period infant birth and death certificate linked file was used to identify infant deaths classified as SIDS (ICD‐10 code R95), SUDI (ICD‐10 codes R00‐Y84 excluding R95) or all other residual codes. The 2002 race and sex‐specific birth cohorts were used to generate the 10th and 90th percentiles of birth weight for each gestational age week from 24 to 42 weeks'' gestation. Demographic variables previously identified as associated with SIDS were used in multiple logistic regression equations to determine the risk for death among SGA and LGA infants (birth weight <10th percentile and >90th percentile, respectively) independent of other potentially confounding variables.

Results

Complete data on 1956 SIDS deaths, 2012 SUDI, and 11 592 other deaths were available. The adjusted OR for SIDS, SUDI and “other” causes for SGA infants was 1.65 (95% CI 1.47 to 1.85), 1.78 (1.59 to 2.00) and 4.68 (4.49 to 4.88), respectively. The adjusted OR for LGA infants was reduced for SIDS (0.73 (0.60 to 0.89)), SUDI (0.81 (0.68 to 0.98)) and “other” (0.42 (0.38 to 0.46)).

Conclusion

Although SGA infants seem to be at slightly increased risk for SIDS or SUDI their risk for “other” residual causes is about 2.5 times higher. LGA infants seem to be at reduced risk of mortality for all causes. The mechanisms by which restricted intrauterine growth increases risk of mortality and excessive intrauterine growth offers protective effects are uncertain.Small for gestational age (SGA) infants have been reported to be at 1.4 to 2.0 times greater risk for sudden infant death syndrome (SIDS).1,2,3,4,5 Other causes of death have also been reported to be associated with being SGA by some authors,6,7 in particular, preterm SGA infants are reported to have an increased risk of death ranging from 2.4 to 3.6 times that of appropriate for gestational age (AGA) preterm infants.8,9 Other authors, however, have observed no increase in risk for other causes of death among term SGA infants after adjusting for racial disparities in birth weight.10 The mechanisms associated with the increased risk for SIDS among SGA infants remain unclear, but some investigators have suggested that the risk may be secondary to the hypoxia these infants are suspected of being exposed to in utero.11,12 Why in utero hypoxia may make an infant more vulnerable to SIDS has been hypothesised to be related to a reduction of serotonergic receptors in multiple brainstem nuclei.13,14Despite the biological plausibility of the hypoxic‐related vulnerability of SGA infants for SIDS, comparative studies of just how much greater risk such an infant has for SIDS compared with other causes of death are not replete in the literature. Thus, the purpose of this analysis was to determine whether SGA infants were at greater risk for SIDS compared with other causes of death. The risk of large for gestational age (LGA) infants for SIDS has not been closely examined and an examination of this relationship was thus included in the analysis. Because of a trend towards the reclassification of SIDS deaths to other causes of sudden unexpected causes of death (SUDI),15 the risk of SUDI excluding SIDS for SGA infants as well as the risk of the remaining residual “other” causes of death among these infants was examined for the USA for the year 2002.     

Parental compliance with home cardiorespiratory monitoring.

AIMS: To evaluate parental compliance with home cardiorespiratory monitoring of premature infants with apnoea, siblings of infants who died of sudden infant death syndrome (SIDS), and infants with an apparent life threatening event (ALTE), during the first month of use. METHODS: A retrospective review of the first month's recordings was conducted on 39 premature infants with apnoea, 13 siblings of SIDS, and 16 infants with ALTE. All infants were singletons. Recommendations during the study period (1992-1994) were for daily use for 23 hours per day. Measurements were average daily hours of use and consistency of use (daily or variable). Gestational age, maternal age, and socioeconomic status as measured by receipt of public assistance were also recorded. RESULTS: Siblings of SIDS were monitored for fewer hours than were premature or ALTE infants. Only 54% of sibings of SIDS were monitored daily, compared to 87% of premature infants and 93% of ALTEs. Within each diagnostic category socioeconomic status did not affect average hours of monitoring. Consistency of use was more evident in those with private insurance, although the trend did not reach significance. CONCLUSIONS: Parents of infants with apnoea of prematurity or ALTE are highly compliant with cardiorespiratory monitoring recommendations in the first month of monitor usage. Siblings of SIDS are monitored for fewer hours and are less likely to be monitored on a daily basis.     

Heart rate variability in infants with apparent life-threatening events

Heart rate variability (HRV) is often used as an index of sympatho-vagal balance. A decreased HRV has been observed in patients with central hypoventilation and in infants who have later succumbed to sudden infant death syndrome (SIDS). The aim of the present study was to investigate whether HRV is altered in infants with apparent life-threatening events (ALTE), a group with an increased risk of SIDS. Fifty infants with ALTE were compared with 50 age- and sex-matched controls. ECG was recorded overnight in all infants. Two sequences of RR intervals free of artefacts were selected from each sleep state and spectral analysis of RR variability was performed. The mean and SD of RR and the low (LFPow) and high (HFPow) frequency power were analysed. In active sleep (AS) the LF/HF ratio was lower in ALTE infants, but no differences were seen in either the LFPow or the HFPow. In quiet sleep (QS), however, ALTE infants had higher SD-RR (p = 0.006), greater HFPow (p = 0.02) and VLFPow (very low frequency power, p = 0.02) than the control infants. The same results were seen when the two sleep states were combined for analysis, ALTE infants had higher SD-RR (p = 0.004), HFPow (p = 0.006) and VLFPow (p = 0.04). Conclusion: The different HRV pattern in ALTE infants compared to healthy controls suggests an altered autonomic control.     

Transepidermal water loss during sleep in infants at risk for sudden death

To search for excessive sweating during sleep in infants considered at risk for sudden infant death syndrome (SIDS), we studied 258 infants during one night. There were 134 normal infants (controls), 85 siblings of SIDS victims (siblings), and 39 infants who survived an apparent life-threatening event (ALTE) with no cause found for the incident. Mean postnatal ages were between 10 and 16 weeks. Transepidermal water evaporation rate was measured from the forehead using an evaporimeter during one night's polygraphic sleep recording. Measurements were made before feedings, during the first part of the night, and evaporation rate values were expressed as grams per square meter of body surface area per hour. In the three groups of patients evaporation rates were significantly lower during rapid eye movement (REM) sleep, compared with values measured during quiet wakefulness or nonrapid eye movement (NREM) sleep. Infants with an ALTE had significantly higher evaporation rate values during NREM sleep than the two other groups (20.1 +/- 1.93, 11.3 +/- 0.68, and 11.5 +/- 0.98 for the ALTE, control, and sibling infants, respectively). The differences were not related to age, sex, weight, or rectal temperature. During NREM sleep, evaporation rate values greater than 25 mg/m2/h were seen in 10/190 (5.3%) of the asymptomatic infants and in 11/36 (30.6%) of the infants with an ALTE. The results are in agreement with reports in the literature of repeated night sweating in infants who eventually died of SIDS. Although we are unable to conclude why evaporation rate values are higher in the ALTE group than in the two other groups, we cannot exclude that it reflects differences in autonomous system activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma ferritin in the assessment of iron status of Indian infants

In order to assess the iron nutritional status of infants, plasma ferritin levels were measured in the infants and children at different time intervals till two years of age from two different socio economic groups. While ferritin levels at 3-4 months age were significantly higher in upper income group infants, levels were almost similar in the subsequent infancy between the two income groups. A close correlation was seen between ferritin levels of mothers and infants at 1-3 months of age (p less than 0.001). Prenatal iron supplements (oral or parenteral) resulted in higher ferritin levels at 4-6 months age as compared to placebo group. While the infants born to mothers receiving parenteral iron did not show any evidence of iron deficiency (serum ferritin levels less than 12 ng/ml), 23.5 and 25.0% of infants in oral iron and placebo group had evidence of iron deficiency between 6-12 months. Thus it would appear that improving the iron status of mothers during pregnancy will have significant impact on the iron status of breast fed infants till 6 months.     

Apparent life threatening events with serious sequelae in infants and young children

Between January 1982 and June 1989 in South Australia 19 infants under 2 years of age have had serious sequelae following an apparent life threatening event (ALTE) for which no cause could be identified. Thirteen of these children have died, four survive with severe hypoxic damage, one has normal psycho-motor development and epilepsy, and another has mental retardation and strabismus. Study of these infants suggests heterogeneity in the cause of both sudden infant death syndrome (SIDS) and ALTE, and occasional links between the two.     

Early neonatal sudden death or near death syndrome. An epidemiological study of 29 cases

Early neonatal sudden death syndrome (SIDS) is a rare but well known disease entity. Between January 1975 and December 1991, 29 full-term newborn infants delivered in our maternity unit and, considered healthy at birth, suffered early SIDS ( n = 15) or early apparent life threatening events (ALTE) ( n = 14). Data from the whole population of live full-term infants born in our hospital during the past five years have been used as a reference (n = 27 841). The general rate of early SIDS was 0.14 per 1000 (15/107 263). Combining early ALTE cases, the overall rate was 0.27 per 1000 (291107263). A postmortem examination was performed for all infants who died (20/29): no cause of death could be determined, and we did not observe a single case with evident sequelae. There were 9 deaths (31 %) within the first hour after delivery and 12 deaths occurred in the early morning hours (04:00–08:00; RR = 3.76; p = 0.0008). The lowest incidence was in the spring (RR = 0.21; p = 0.03). There was a tendency for an increased incidence during the weekend and the summer. No influence of sex, maternal age, gestational age, infant weight presentation, delivery, anesthesia or presence of meconium-stained fluid was found. In our opinion, SIDS can take place even during the first hour of life and it is not possible to predict when a baby might be affected. Pediatrically trained caregivers, close observation by the mother during the first few days and resuscitation facilities in maternity wards may be the most important preventive measures to reduce the risk of early SIDS and the consequences of ALTE in the early newborn period.     

Associated and prognosis in apparent life threatening events (ALTE)

OBJECTIVE: To verify the etiology and prognosis of ALTE in infancy and its possible relationship to Sudden Infant Death Syndrome (SIDS). METHODS: We studied a group of infants that presented ALTE episodes and were evaluated in our hospital. First we reviewed their clinical history and polysomnographies, then we sent a letter to the families with questions regarding the outcome. RESULTS: 56 patients were included. 92% had ALTE during their first 6 months and 83% in the first trimester. Symptomatic ALTE predominated (71%). The disease most frequently associated was gastroesophageal reflux, followed by neurological diseases. The follow up showed 51.5% of normal outcome, 4 children repeated ALTE, no cases of SIDS were registered. CONCLUSIONS: Our results showed that multifactorial etiologies can be associated to ALTE, and the outcome is generally related to the associated disease. We did not observe any relationship between ALTE and SIDS considering a predominantly symptomatic ALTE population.