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J Milerad

Publications and source records attributed to J Milerad.

At least 19 recordsLinked to original sources

International Child Care Practices Study: infant sleeping environment.

BACKGROUND: The International Child Care Practices Study (ICCPS) has collected descriptive data from 21 centres in 17 countries. In this report, data are presented on the infant sleeping environment with the main focus being sudden infant death syndrome (SIDS) risk factors (bedsharing and infant using a pillow) and protective factors (infant sharing a room with adult) that are not yet well established in the literature. METHODS: Using a standardised protocol, parents of infants were surveyed at birth by interview and at 3 months of age mainly by postal questionnaire. Centres were grouped according to geographic location. Also indicated was the level of SIDS awareness in the community, i.e. whether any campaigns or messages to "reduce the risks of SIDS" were available at the time of the survey. RESULTS: Birth interview data were available for 5488 individual families and 4656 (85%) returned questionnaires at 3 months. Rates of bedsharing varied considerably (2-88%) and it appeared to be more common in the samples with a lower awareness of SIDS, but not necessarily a high SIDS rate. Countries with higher rates of bedsharing appeared to have a greater proportion of infants bedsharing for a longer duration (>5 h). Rates of room sharing varied (58-100%) with some of the lowest rates noted in centres with a higher awareness of SIDS. Rates of pillow use ranged from 4% to 95%. CONCLUSIONS: It is likely that methods of bedsharing differ cross-culturally, and although further details were sought on different bedsharing practices, it was not possible to build up a composite picture of "typical" bedsharing practices in these different communities. These data highlight interesting patterns in child care in these diverse populations. Although these results should not be used to imply that any particular child care practice either increases or decreases the risk of SIDS, these findings should help to inject caution into the process of developing SIDS prevention campaigns for non-Western cultures.

Beds↗

Changes in the epidemiology of sudden infant death syndrome in Sweden 1973-1996.

BACKGROUND: From the early 1970s to the early 1990s, there was a significant rise in the incidence of sudden infant death syndrome (SIDS) in Scandinavia. Following the risk reducing campaign, the incidence has fallen to about the same level as in 1973. AIMS: To identify the changes that have occurred in the epidemiology of SIDS. METHODS: We compared the Swedish part of the Nordic Epidemiological SIDS Study (NESS), covering the years 1992-1995, with two earlier, descriptive studies during this period. To assess the changing effects of risk factors, we analysed data from the Medical Birth Registry of Sweden, covering the years 1973-1996. RESULTS: There was a predominance of deaths during weekends in the 1970s and 1990s. The seasonal variation was most notable in the 1980s. The proportion of young mothers decreased from 14% to 5%. Cohabitation (living with the biological father) was as frequent in the 1990s as in the 1970s. The prevalence of high parity, admissions to neonatal wards, low birth weight, prematurity, and multiple pregnancies were all increased in the 1990s compared to the 1970s. No significant change in the prevalence of previous apparent life threatening events was found. Deaths occurring in cars diminished from 10% to below 2%. In the data from the Medical Birth Registry of Sweden, there were significantly increased odds ratios after the risk reducing campaign of the risk factors smoking during early pregnancy and preterm birth. We could find no increased effects of maternal age, parity, or being small for gestational age over time. The rate of deaths at weekends remained increased; the median age at death fell from 90 to 60 days. Seasonal variation was less notable in the periods of low incidence.

Age Distribution↗

[Patent ductus arteriosus. A common clinical problem in extremely premature infants].

An analysis was made of the incidence and treatment regimen of symptomatic patent ductus arteriosus (PDA) in 95 preterm infants treated 1997-1999 in a level three intensive care unit in Stockholm. 47 infants (49 percent) had PDA. Of these 17 infants were managed conservatively (fluid restriction and diuretics), 13 were treated with indomethacin, 10 underwent primary surgical ligation and 7 were treated with indomethacin first and surgery later on. The proportion of infants given "active" therapy (surgery and/or indomethacin) rose from 50 percent in 1997 to 85 percent in 1999. In a stepwise multiple regression analysis low birthweight, septicaemia and need for mechanical ventilation were all independently associated with PDA.

Cyclooxygenase Inhibitors↗

[Fiberoptic endoscopy confirms the cause of upper respiratory obstruction in small children. The most common causes to referrals are sleep apnea syndrome and inspiratory stridor].

Guidelines for the clinical investigation of young children with stridor and sleep apnea are presented. Clinical examination and flexible videolaryngoscopy performed in local anaesthesia are the most important diagnostic tools for this group of children. If the impairment is severe or an objective evaluation is needed the child should also undergo nocturnal polygraphic recording and lung function tests. Out of 43 children examined with flexible videolaryngoscopy 21 had positive findings, laryngomalacia being the most common diagnosis. Flexible videolaryngoscopy is a good complement to laryngoscopy under general anaesthesia. It can be performed as early as in the neonatal period.

Child, Preschool↗

Breathing patterns, oxygen and carbon dioxide levels in sleeping healthy infants during the first nine months after birth.

UNLABELLED: Data on arterial oxygen saturation (SaO2), transcutaneous PO2, pCO2 (tcpO2, tcpCO2) and breathing patterns in sleeping healthy term infants were obtained during the first 9 mo after birth. Forty-four healthy infants, mean GA at birth 40 +/- 1.0 wk, mean BW 3520 +/- 562 g were examined between 2 wk and 9 mo postnatally in a cross-sectional study. SaO2, tcpO2, tcpCO2, heart rate (HR), rib cage and abdominal respiratory movements were recorded during natural nocturnal sleep, stratified for sleep states (active sleep (AS), indeterminate sleep (IS), quiet sleep (QS)). The data on AS and IS were pooled as in previous studies. The variables were analysed with respect to age. SaO2 in AS + IS and QS was 96.1 +/- 1.3%, 96.6 +/- 1.4%, respectively. TcpO2 in AS + IS was 10.6 +/- 1.1 kPa and 10.7 +/- 1.3 kPa in QS, while tcpCO2 in AS + IS was 5.4 +/- 0.3 kPa and 5.4 +/- 0.4 kPa in QS. Neither SaO2 nor tcpO2 was influenced by age. TcpCO2 decreased significantly postnatally. Five infants (11.3%) experienced episodes of hypoxaemia with a mean decrease in SaO2 to 86 +/- 1.5%. In four infants these hypoxaemic episodes were linked to upper airway obstructions. Episodes of SaO2 < 90% in conjunction with a decrease in HR to < 100 bpm were detected in one infant only. Periodic breathing (PB) was observed in 38.6% of infants. CONCLUSION: Oxygenation and carbon dioxide levels in sleeping healthy term infants were comparable to those reported in older children. Hypoxaemic episodes, if present, are associated with upper airway obstruction. PB, often assumed to be a pathological feature, is a normal breathing pattern in this age group.

Age Factors↗

Heart rate variability in infants with apparent life-threatening events.

UNLABELLED: 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.

Analysis of Variance↗

Nicotine delays arousal during hypoxemia in lambs.

A decreased ability to arouse from sleep in response to arterial hypoxemia may lead to severe asphyxia and has been proposed as a mechanism of sudden infant death syndrome. Based on previous observations that nicotine exposure, a major environmental risk factor for sudden infant death syndrome, may impair hypoxic defense in neonates, we hypothesized that a short-term infusion of nicotine could impair hypoxic arousal through interference with oxygen-sensing mechanisms. Seven chronically instrumented unanesthetized lambs were studied at the age of 4.6 +/- 1.3 d during normoxia and acute hypoxia (0.1 fraction of inspired oxygen) for 5 min. Ventilation, transcutaneous Hb oxygen saturation, blood pressure, heart rate, and time to arousal were compared during a control saline infusion and during a 0.5 microg x kg(-1) x min(-1) nicotine infusion. Activity states, i.e. wakefulness and quiet sleep as well as arousal, were defined by EEG, nuchal electromyogram, and electrooculogram. Each lamb acted as its own control. Arousal from quiet sleep occurred significantly later during nicotine infusion compared with control (177 +/- 93 versus 57 +/- 41 s, p < 0.01) and at a lower transcutaneous Hb oxygen saturation (60 +/- 12 versus 79 +/- 12%, p < 0.01) (paired t test). The ventilatory response to hypoxia in wakefulness was similar during both conditions but was significantly attenuated in quiet sleep during nicotine infusion (p < 0.001, 2-way ANOVA repeated-measures design). Blood pressure and heart rate responses were similar during both conditions. These results suggest that a brief nicotine exposure blunts oxygen sensitivity in young lambs, a finding of potential relevance for sudden infant death syndrome.

Animals↗

Reduced inspiratory drive following laryngeal chemoreflex apnea during hypoxia.

Respiratory inhibition following laryngeal water administration was investigated by breath-by-breath analysis of inspiratory ventilation (VI) and central inspiratory drive (P0.1) in 15 unanesthetized lambs studied in 0.21 FIO2 (PaO2: 82-92 torr, PaCO2 41-43 torr) and in 0.1 FIO2 (Pao2 30-34 torr, PaCO2 32-33 torr). During the 30 sec period after stimulation, VI decreased significantly compared to prestimulation levels both in 0.21 FIO2 (-22, -21 and -18%) and in 0.1 FI(O2), (-16, -23 and -19%) at 5, 16 and 29 days, respectively. In contrast, P0.1 remained at prestimulation levels during normoxia in all age groups (1, 10 and 9%, NS), but decreased significantly during hypoxia (-11 and -13%, P < 0.05) at 16 and 29 days, respectively. Poststimulation apnea duration was significantly related to the decrease in VI (P < 0.001) but not to the change in P0.1. Laryngeal stimulation during hypoxemia/hypocapnia induces a prolonged decrease of central inspiratory drive in postneonatal lambs, a finding of potential significance for the mechanisms of sudden infant death syndrome.

Age Factors↗

Growth hormone treatment increases CO(2) response, ventilation and central inspiratory drive in children with Prader-Willi syndrome.

UNLABELLED: We studied whether the beneficial effects of growth hormone (GH) treatment on growth and body composition in PWS are accompanied by an improvement in respiratory function. We measured resting ventilation, airway occlusion pressure (P(0.1)) and ventilatory response to CO(2) in nine children, aged 7-14 years, before and 6-9 months after the start of GH treatment. During GH treatment, resting ventilation increased by 26%, P(0.1) by 72% and the response to CO(2) by 65% (P < 0.002, <0.04 and <0.02, respectively). This observed increase in ventilatory output was not correlated to changes in body mass index. CONCLUSION: Treatment of children with Prader-Willi syndrome (PWS) seems to have a stimulatory effect on central respiratory structures. The observed increase in ventilation and inspiratory drive may contribute to the improved activity level reported by parents of PWS children during growth hormone therapy.

Adolescent↗

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Journal Article↗

Objective measurements of nicotine exposure in victims of sudden infant death syndrome and in other unexpected child deaths.

OBJECTIVE: Self-reported maternal smoking is associated with a dose-related-increase in the risk of sudden infant death syndrome (SIDS). The aim of this study was to measure objectively whether victims of SIDS are more exposed to tobacco smoke before death than infants who die unexpectedly of other causes. DESIGN: Continine levels in pericardial fluid were used as an indicator of exposure. Levels > 5 ng/mL indicated significant exposure, and levels > 20 ng/mL indicated heavy exposure. Samples were obtained from all sudden deaths in children < 7 years of age that occurred from 1990 through 1993 in southeastern Norway. Twenty four infants died of SIDS, 12 infants of infections, and 9 of accidents (median age 4.5, 5, and 35 months, respectively). RESULTS: Compared with the age-matched infectious deaths, a significantly higher proportion of victims of SIDS had been significantly (92% vs 67%) or heavily exposed (25% vs 0%) to nicotine, (P < .05). Median cotinine levels in infants with SIDS, 15.8 ng/mL, were significantly higher than in infants who had infectious deaths 7.1 ng/mL (P < .003) but were comparable to those of accident victims (12.9 ng/mL, not significant). CONCLUSIONS: Victims of SIDS are more often and more heavily exposed to tobacco smoke doses before death than are infants who have sudden infectious deaths. Accidental death in infancy and childhood is often associated with a significant exposure to nicotine.

Humans↗

Sleeping position, breastfeeding, bedsharing and passive smoking in 3-month-old Swedish infants.

Parents of 1028 infants who attended community-based infant health clinics were interviewed concerning infant sleeping position, feeding habits, bedsharing and passive smoking at 3 months of postnatal age. In addition, they were asked to state which source of information had mainly influenced them in the choice of the sleeping position. Fifteen per cent of the infants were regularly laid to sleep in the prone position, compared with 72% (1991) before official guidelines concerning infant sleeping position were issued. The overall prevalence of exclusive breastfeeding was 70.4%. Prevalence of maternal smoking was 17.9% and 22.8% of the infants were regularly bedsharing with the parents. Those mothers who did not comply with official recommendations regarding infant sleeping position were also less likely to follow other recommendations concerning infant care practices. Prone sleeping infants were more likely to be formula fed and exposed to passive smoking, and hence associated with additional risk factors for sudden infant death syndrome.

Breast Feeding↗

A case-control study of smoking and sudden infant death syndrome in the Scandinavian countries, 1992 to 1995. The Nordic Epidemiological SIDS Study.

AIM: To establish whether smoking is an independent risk factor for sudden infant death syndrome (SIDS), if the effect is mainly due to prenatal or postnatal smoking, and the effect of smoking cessation. METHODS: The analyses were based on data from the Nordic epidemiological SIDS study, a case-control study with 244 cases and 869 controls. Odds ratios were computed by conditional logistic regression analysis. RESULTS: Smoking emerged as an independent risk factor for SIDS, and the effect was mainly mediated through maternal smoking in pregnancy (crude odds ratio 4.0 (95% confidence interval 2.9 to 5.6)). Maternal smoking showed a marked dose-response relation. There was no effect of paternal smoking if the mother did not smoke. Stopping or even reducing smoking was beneficial. SIDS cases exposed to tobacco smoke were breast fed for a shorter time than non-exposed cases, and feeding difficulties were also more common. CONCLUSIONS: Smoking is an independent risk factor for SIDS and is mainly mediated through maternal smoking during pregnancy. Stopping smoking or smoking less may be beneficial in reducing the risk of SIDS.

Breast Feeding↗

The divergent ventilatory and heart rate response to moderate hypercapnia in infants with apnoea of infancy.

BACKGROUND: Inspired CO2 is a potent ventilatory stimulant exhibiting a paradoxical inhibitory effect on breathing at high concentrations. Severe respiratory depression as a result of CO2 rebreathing during sleep has been implicated as a possible trigger factor in sudden infant death syndrome (SIDS). OBJECTIVE: To investigate the ventilatory and heart rate (HR) responses to inhaled CO2 in infants with apnoea of infancy, a group believed to be at increased risk of SIDS. STUDY DESIGN: Thirty one infants with severe sleep related apnoea, 31 infants with mild recurrent apnoea, and 31 age and sex matched controls for the infants with severe sleep related apnoea were studied. HR was computed from digitised RR intervals, "ventilation" was recorded by inductance plethysmography, and PCO2 and PO2 were monitored by transcutaneous electrodes. The ventilatory and HR responses to CO2 were expressed as percentage increase in ventilation and change in HR/unit change in transcutaneous PCO2. RESULTS: The mean increase in transcutaneous PCO2 during CO2 challenge (0.45 kPa = 3.4 mm Hg) resulted in a mean increase in ventilation of 291%/1 kPa (7.3 mm Hg) increase in transcutaneous PCO2, with no difference between the groups. A significant difference between infants with severe sleep related apnoea and mild recurrent apnoea versus controls (p < 0.02, p < 0.01, respectively) was found in their HR response to CO2 challenge: HR decreased in 12 severe sleep related apnoea infants and 10 infants with mild recurrent apnoea, but only in two controls. CONCLUSION: Infants with apnoea of infancy frequently show a paradoxical decrease in HR during CO2 challenge, possibly because of an insufficient ability to mobilise cardiovascular defence mechanisms when challenged with hypercapnia.

Apnea↗

Incidence of cleft lip and palate and risks of additional malformations.

OBJECTIVE AND METHODS: Children with cleft lip and/or palate (n = 251) born between 1991 and 1995 in the county of Stockholm, Sweden, were studied with reference to incidence and rate ratios (RRs) of different types of clefts, gender, birth weight, mother's age, and length of pregnancy. Children who had clefts and additional malformations were compared with children who had clefts but no additional malformations. RESULTS: The incidence of clefts was 2.0/1000 live births, and it was higher among males than among females. The RR, an index of relative risk, was 1.58. The main groups, children with isolated cleft lip, children with cleft lip and palate, and children with isolated cleft palate, showed similar incidence values (0.6-0.7/1000 live births). Children with bilateral clefts had an incidence of 0.3/1000 live births. Additional malformations were found in approximately every sixth newborn with a cleft when children with Robin sequence were excluded. There was a tendency for newborns with bilateral clefts to have additional malformations (RR = 1.36; confidence interval = 0.74-2.49). Children with clefts and additional malformations had lower birth weight and were born earlier than children with clefts only. CONCLUSION: Preterm cleft children with low birth weight should be screened for the presence of other birth defects.

Adult↗

Sudden infant death and prevalence of whooping cough in the Swedish and Norwegian communities.

UNLABELLED: Whooping cough (WC) has been suggested to be a trigger factor for sudden infant death (SID), the proposed mechanism being unrecognised hypoxaemic episodes. In contrast to Norway, Sweden ceased its immunisation programme against Bordetella pertussis (BP) in 1979. We investigated the relation between SID mortality and the prevalence of BP during 1983 to 1988, by month, in the two ethnically and socially similar, bordering countries adopting different strategies towards WC. In addition, the greater Stockholm area was analysed. For both countries the prevalence of BP was collected from monthly reports by regional health officers. SID mortality rates were provided by the Norwegian Central Bureau of Statistics and the SID registry at the Swedish National Board of Health and Welfare. The relation between SID mortality rate and prevalence of WC, by month, was analysed by linear regression. In addition, the consistency of seasonal fluctuations was investigated by analysing the covariance between average, pooled, monthly values of the two variables. SID mortality rate followed significantly the monthly prevalence of BP in Sweden (P < 0.01) and Stockholm (P < 0.0001) during the study period. In Norway there was a significant correlation only during the epidemic outbreak of WC (P < 0.05), but not for the whole study period. When controlling for seasonality a significant correlation remained in the urban area of Stockholm (P < 0.05). CONCLUSION: It is suggested that covariations between WC and SID mortality rate may be related to transmission rate and immunisation status of the investigated population.

Analysis of Variance↗

The decline in the incidence of SIDS in Scandinavia and its relation to risk-intervention campaigns. Nordic Epidemiological SIDS Study.

A prospective case-control study of sudden infant death syndrome (SIDS) in Norway, Denmark and Sweden between September 1, 1992 and August 31, 1995 comprised 244 cases and 869 matched controls. After the introduction of risk-intervention campaigns, the SIDS incidence decreased from 2.3/1000 live births in Norway, 1.6 in Denmark and 1.0 in Sweden to 0.6/1000 or fewer in all the Scandinavian countries in 1995. The decrease paralleled a decline in the prone sleeping position and there was an accompanying parallel fall in total postneonatal mortality in all three countries. Thus, the risk-reducing campaigns for SIDS have been successful not only in Norway and Denmark, starting from relatively high incidences, but also in Sweden, starting from a low incidence. During the study period, a gradual increase was observed for the effects of prone sleeping, smoking and bottle-feeding as risk factors for SIDS.

Case-Control Studies↗