Sudden infant death syndrome and near sudden infant death syndrome: a review of the literature, 1964 to 1982

Factors associated with bed sharing and sleep position in Thai neonates

BACKGROUND

Sleep in a supine position and in a bed separate from but proximate to adults is recommended, in several Western countries, to prevent Sudden Infant Death Syndrome (SIDS). Cultural differences and a lower rate of SIDS in Asian populations may affect concern with this problem and thus infant sleeping arrangements. Objective To study bed sharing and sleep position in Thai neonates and the relationship to infant and maternal characteristics.

METHODS

A cross-sectional survey based on interviews with parents of infants aged 21 days old, was conducted under the Prospective Cohort Study of Thai Children.

RESULTS

Of the total sample, 2236/3692 (60.6%) infants shared a bed with their parents. Sixty per cent of the parents placed their infants to sleep in a supine position, 32.2% on their side and 4.9% in a prone position. Bed sharing was associated with older maternal age, higher education, Muslim mother, and with work status of professional career or unemployed. Placing the infants to sleep in a prone position was associated with infant birth weight of greater than 2500 g, older maternal age, higher education, Buddhist mother, mother with professional career and middle-class household economic status.

CONCLUSIONS

Infant bed sharing is a common practice in the Thai culture, as in other Asian countries. The prone sleep position is less common than in Western populations. The main factor associated with both bed sharing and putting infants to sleep in the prone position was a higher maternal socioeconomic status (SES), in contrast to previous studies in some Western countries in which both practices were associated with low maternal SES. Cultural differences may play an important role in these different findings.

Intestinal epithelial damage in sids babies and its similarity to that caused by bacterial toxins in the rabbit

Sections of the duodenum, jejunum, ileum, caecum and large intestine from 14 sudden infant death syndrome (SIDS) babies were examined by scanning (SEM) and transmission electron microscopy (TEM). The type and amount of damage was characterised and quantitated and compared with the presence of Clostridium perfringens, Clostridium difficile, Escherichia coli and Staphylococcus aureus in faecal samples from the babies and toxins from the bacteria in faecal samples and serum from the babies. The data were compared with the damage that these toxins cause to the rabbit intestinal epithelium (see the previous paper in this issue). Damage was present in most of the SIDS samples, varying from 0 to 96%, and most damage occurred when the faecal samples contained the above bacteria and their toxins. Damage varied from removal of microvilli, damage to villus tips, separation of and removal of epithelial cells from the lamina propria, and removal of enterocytes leaving goblet and tuft cells, to damage and breakdown of the lamina propria. The results support the hypothesis that the cause of death in a significant proportion of SIDS babies may result from the absorption of toxins from the intestinal tract initiating a toxic shock reaction.

Response of the cricothyroid and thyroarytenoid muscles to stereotactic injection of substance P into the region of the nucleus tractus solitarius in developing dogs

Substance P (SP), a putative sensory neurotransmitter, mediates reflex laryngeal adductor activity in developing dogs. Such reflex activity includes life-threatening laryngospasm induced by stimulation of distal esophageal afferent nerves. The site of SP's activity is unknown. This research was undertaken to determine whether injection of SP into the nucleus tractus solitarius (NTS) of developing beagles alters laryngeal adductor motor activity. Six animals, 57 to 78 days of age, underwent stereotactic injection of 5 to 10 microL of SP into the region of the NTS, identified by electrical stimulation of the ipsilateral superior laryngeal nerve. In 8 additional studies, SP was injected into the cerebellum (2) or brain stem (6) distant from the NTS. Cardiovascular and electromyographic (EMG) responses of the diaphragm and the cricothyroid (CT) and/or thyroarytenoid (TA) muscles were recorded in all 6 animals. Injection of SP into the region of the NTS induced a decrease in blood pressure in all animals and an increase in either ipsilateral CT or TA activity. Three of these animals experienced mixed apnea characterized by sustained EMG activity (spasm) of the ipsilateral CT or TA muscles and an absence of diaphragm EMG activity. The apnea event was fatal in 1 of these animals. In the 6 animals who underwent injections in the brain stem but outside the region of the NTS, diaphragm and laryngeal EMG activity generally did not change after injection of SP, with the exception of 1 animal who experienced a mild, short-lived increase in ipsilateral CT activity. A brief phasic increase in ipsilateral CT activity was seen in both animals who underwent injection of SP into the cerebellum. A putative sensory neurotransmitter, SP evokes ipsilateral CT and/or TA EMG activity when injected into the region of the NTS in developing beagle dogs. This research suggests that SP in the NTS may play a role in mediating life-threatening laryngeal adductor reflexes in developing mammals and may provide important information regarding therapeutic intervention.

Sudden infant death syndrome: a hypothesis

A study of the strikingly low incidence of sudden infant death syndrome in Eastern countries revealed significant differences in infant handling thought to have an etiological bearing; therefore this writer suggested that adoption of certain Eastern methods of nursing may reduce the incidence of sudden infant death syndrome. A dramatic fall in incidence has resulted from implementing one of the suggestions made by the writer in 1983, namely the abandonment of the prone position, after initial opposition. The present hypothesis sets out to give a scientific explanation for this fall, and is a unified hypothesis explaining certain puzzling and disparate features of sudden infant death syndrome such as the remarkable winter incidence, age incidence, and the occurrence of sudden infant death syndrome during sleep, and is based on a postulated disturbance in thermoregulatory function (a unique hypothermia). Recommendations are made for evolving a test for sudden infant death syndrome-proneness and a possible method of treatment of a fatality within a short time frame.

Is sudden infant death syndrome a problem in Zimbabwe?

In order to determine the incidence of sudden infant death syndrome (SIDS) in Zimbabwe, a prospective study was done in infants aged 1 month to 1 year who were certified as dead at home and brought to the accident and emergency department of Mpilo Central Hospital in Bulawayo from July 1992 to June 1993. There were four cases of SIDS among a total of 18,889 registered live births, giving an incidence rate for SIDS of approximately 0.2/1000 (95% CI 0.004-0.4/1000). SIDS appears to be uncommon in black Africans of low socio-economic status in Zimbabwe. Child rearing practices, parental lifestyle and a home environment different from that of Europeans might explain the low incidence of SIDS in the population.

Changes in the concentration and distribution of immunoglobulin-producing cells in SIDS palatine tonsils

Seventeen sudden infant death syndrome (SIDS) cases and 9 controls, were examined immunohistochemically with regard to the presence of IgA-, IgM-, IgD, and IgG, as well as for the subtypes IgG1-, IgG2-, IgG3-, and IgG4-immunocytes. Differences in compartmentalization were also investigated. Differences were demonstrated between SIDS and controls in total number of IgG cells per 0.1 mm2 tissue area (median: 18.3, range: 12.3-30.2 versus median: 6.3, range: 2.0-14.6) (p < 0.01), and for IgA immunocytes (median: 3.9, range: 2.4-5.0 versus median: 1.5, range: 1.1-3.7) (p < 0.05), while no differences were demonstrated for IgM cells (median: 1.8, range: 1.2-3.3 versus median: 1.8, range: 0.7-5.6) or IgD cells (median: 1.9, range: 0.8-2.9 versus median: 1.6, range: 0.7-2.4). Differences were demonstrated between SIDS and control IgG plasma cells in all the four palatine tonsillar compartments; germinal centre (p < 0.01), mantle zone (p < 0.05), interfollicular area (p < 0.01) and reticular epithelium (p < 0.01). Furthermore, the number of IgA cells was higher in SIDS vs. controls in both the germinal centre (median: 1.4, range: 0.6-2.1 versus median: 0.6, range: 0.3-1.3) (p < 0.05) and in the interfollicular area (median: 2.2, range: 1.1-3.1 versus median: 0.5, range: 0.4-2.0) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Is the higher postneonatal mortality in lower social status groups due to SIDS?

In order to study the influence of sociodemographic factors, postneonatal mortality of all live births surviving the neonatal period registered in the Norwegian Medical Birth Registry in 1978-1982 were examined (n = 209,030). Postneonatal deaths (n = 634) were divided into two categories; deaths due to the sudden infant death syndrome (SIDS) (n = 359) and deaths due to other causes (non-SIDS) (n = 275). SIDS and non-SIDS deaths showed different relationships to sociodemographic factors, and the associations appeared to be different for first-born and later born children. SIDS mortality was highest for first-born offspring when the mother was young (adjusted relative risks (RR) 2.3) and had a low educational level (adjusted RR 4.9). For later-born offspring no association between maternal educational level and SIDS was found, while young maternal age (adjusted RR 4.4) and unmarried status (adjusted RR 2.3) were closely associated with SIDS. In the multivariate model, however, there were no statistically significant associations between non-SIDS and sociodemographic factors for first-born or later-born children. Thus it appears that the increased postneonatal mortality in lower social groups can be explained by an association with SIDS.

The micro-environment of the sleeping newborn piglet covered by bedclothes: gas exchange and temperature

This study followed the thermal and gaseous micro-environment of the newborn piglet sleeping under two levels of bedding insulation. After 1 h in the piglet's thermal comfort zone, the head of each piglet was covered for 2 h with bedding either 12 mm or 21 mm thick. Body temperature rose rapidly, but the arterial gases showed no change in the direction of asphyxia; with the thicker covering PaO2 was unchanged and PaCO2 fell and pH rose. These changes were despite a small rise in environmental PCO2 and fall in PO2 but were also minimized by the piglet's ability to avoid profound hypocapnia by panting at a very low tidal volume. No significant changes in blood gases occurred with the thinner bedding; the temperature rose markedly but more slowly. It is suggested that human babies submerged under bedclothes for any length of time would be more likely to succumb to the effects of hyperthermia than of asphyxia.

An epidemiological survey of SIDS in the Sydney metropolitan area

Records of 1049 cases of Sudden Infant Death Syndrome (SIDS) (100%) in the Sydney metropolitan area (SMA) from 1980 to 1989 were analysed in relation to ambient temperature, geographical distribution and socio-economic scale. The SIDS rate varied between eastern and western Sydney and between statistical subdivisions; it peaked sharply in July, coinciding with the monthly mean minimum daily temperature (MMMDT; 6.5 and 5.4 degrees C, respectively). The inverse linear relationship between the SIDS rate and the MMMDT for the regions and the subdivisions was highly significant (P < 0.001). The SIDS rate showed a significant inverse linear relationship to two socio-economic scales (allotment and house value) for 82 of the 87 suburbs (94%) of the SMA. Temperature, indicative of cold weather, was the major factor determining SIDS rates, and this, together with socio-economic factors, largely explains the observed geographical distribution of SIDS rates in the SMA.

Enlargement of the tongue in sudden infant death syndrome

Anatomic details of the infantile oropharynx and relationships to possible airway obstruction in sudden infant death syndrome (SIDS) are understood incompletely. Tonkin recognized this in 1975, suggesting that enlargement of the tongue might be important in SIDS, within the context of other anatomic and physiologic factors unique to early life. We therefore conducted a morphometric study of the tongue in 100 victims of SIDS and 36 control infants; the latter group consisted of infants with the same range in age and body size who had grown normally and died acutely. Highly significant differences in tongue weight, width, and thickness were demonstrated between the two groups by linear regression and analysis of covariance. Two multivariate techniques, stepwise discriminant analysis and factor analysis, identified marked discordance between somatic and lingual size in SIDS and a statistical uniqueness in tongue thickness. Certain explanations for lingual enlargement in SIDS were ruled out: redistribution of fluid and other effects of death, postmortem interval, duration and mode of feeding, and smallness of control tongues. At present, the functional significance of these observations is unclear. The effects of both normal and increased tongue size on airway patency are, however, widely recognized. Further studies of the enlarged tongue, addressing such topics as in situ anatomy and developmental mechanisms, are necessary to establish the potential for pathophysiologic consequences in SIDS.

Airway resistance of the posterior nasal pathways in sudden infant death victims

In order to test the hypothesis that infectious swelling of parts of the inner nose causes airway obstruction and is of aetiological significance for sudden infant death (SID), we measured the airway resistances of the prepared posterior nasal pathways of 55 SID victims and 7 infants who died of other causes. About 25% of the SID victims but none of the control cases had strongly elevated nasal resistances; over 4000 kPa.s.m-3 up to unmeasurable values. A histological survey showed that about 50% of the SID cases and only 1 of the control cases exhibited distinct to severe signs of inflammation of the nasal mucous membranes. No correlation was found between nasal resistance and age, sex, body weight, body length, head circumference, or histological findings. We conclude that an elevated nasal resistance plays a role in some SID cases and that SID is rather the result of different processes than a monocausal disease.

Laryngomalacia: a cause for early near miss for SIDS

Six infants had recurrent apnea of infancy episodes (near miss sudden infant death syndrome) during their neonatal period. Physical examination and laboratory investigation were normal. Polygraphic sleep monitoring revealed recurrent obstructive sleep apnea. These infants underwent fiberoptic endoscopy which showed that airway obstruction occurred at the laryngeal orifice as a result of laryngomalacia. It is suggested that laryngomalacia may be a cause for early apnea of infancy.

Preventing the sudden infant death syndrome

Current efforts in the US to prevent the sudden infant death syndrome (SIDS) are largely based on pneumocardiogram screening and home apnoea monitoring. This technology does not prevent most SIDS deaths because the screening procedures lack the sensitivity and specificity needed to identify most high risk infants. In the UK the largest efforts to prevent SIDS have been based on infant health surveillance. These efforts appear to have been ineffective and along with the US failures highlight the need for new strategies to prevent SIDS. One strategy might be to develop methods to avoid known risk factors for SIDS. Prominent among these risk factors are cigarette smoking and the use of psychotropic drugs during pregnancy, overheating and infections in infants. Possible approaches to avoid these and other risks are described in the present paper.

Immunohistological localisation of staphylococcal toxic shock syndrome toxin (TSST-1) antigen in sudden infant death syndrome

A polyclonal antiserum to toxic shock syndrome toxin (TSST-1) and a standard immunoperoxidase technique were used on formalin fixed tissues from 50 cases of sudden infant death syndrome (SIDS) to determine if the syndrome was associated with bacterial infection. There was strong specific staining in the renal tubular cells in nine (18%) cases. A similar pattern of staining was seen in three of a series of 50 kidneys selected for comparison from a wide range of necropsy cases. The staining was finely granular within the cytoplasm of proximal convoluted tubular cells and diffuse in tubular cell nuclei. In an attempt to validate the staining pattern the immunoperoxidase technique was also performed on formalin fixed kidneys from rats which had been given intravenous injections of crude bacterial products containing TSST-1. These showed coarse granular cytoplasmic staining in proximal convoluted tubules with some diffuse nuclear staining. This pattern was not seen in controls injected with saline. These results indicate that TSST-1 might have a pathogenic role in some cases of SIDS.

Lung immunoglobulins in the sudden infant death syndrome

The incidence of the sudden infant death syndrome parallels that of respiratory tract infections in the paediatric community. On the basis that the aetiology of the sudden infant death syndrome may lie in an unusual response to a trivial intercurrent respiratory infection a necropsy study was carried out investigating pulmonary immunoglobulins in 16 victims of the syndrome and a series of infants (controls) who had died of non-pulmonary causes. Compared with the controls victims of the sudden infant death syndrome had grossly raised concentrations of IgG, IgM, and to a less extent IgA in lung lavage samples. In addition, pulmonary interstitial and terminal airway cells expressing these immunoglobulins were identified far more often in victims than controls. The study failed to determine whether the increased immunoglobulin concentrations were a consequence of an unusual response to a trivial infection or an expression of otherwise altered immunological control in the respiratory tract. Epidemiological evidence and the findings of this study suggest that the respiratory tract is the prime target organ in the sudden infant death syndrome.

[Selective detection of cytomegalovirus by in situ hybridization]

In two SIDS autopsy cases, in situ hybridization with biotin-labeled DNA probes was used to demonstrate a specific cytomegalovirus (CMV) infection in paraffin-embedded tissue sections. This technique represents a rapid, specific, and highly sensitive tool for the detection of CMV infections and is recommended for routine examination in other suspected viral infections, particularly in cases connected with SIDS.

Home monitoring in children at risk of sudden infant death

Electronic home monitoring has been advocated as a means of preventing sudden infant death syndrome (SIDS). Special emphasis has been placed on apnoea monitoring. The evaluation of the preventive aspect of home monitoring is exceedingly difficult considering the ethical and statistical implications. Major problems arise as the monitoring is done by the parents in a situation different from the one in the intensive care unit. The relative advantages of pulse oximetry and inductance plethysmography are outlined in comparison with other techniques like impedance pneumography, apnoea mattress and apnoea capsule.

Comparison of infants dying from the sudden infant death syndrome with matched live controls

Development, medical history and social background of 79 sudden infant death syndrome (SIDS) and 79 age matched controls were compared. SIDS was associated with a high proportion of S.G.A. infants, more hospital admissions and increased reporting of symptoms, particularly irritability, by parents. Social factors did not play a significant role with no evidence of marked social deprivation or lack of caring in either group. When this background data from both groups was compared there was no evidence of reliable predictors of sudden infant death.

Grief reaction to sudden unexpected cardiorespiratory arrest in a normal newborn nursery

The authors report two cases of sudden unexpected cardiorespiratory arrest occurring in a normal newborn nursery. They discuss the impact on the families and hospital personnel. The nursing and medical staff demonstrated many of the reactions experienced by families of sudden infant death syndrome (SIDS) victims, including shock, anger, guilt, disbelief, fear, and doubt. The manner in which hospital personnel were supported and counseled is discussed. Specific clinical implications of these cases, including the need to provide for appropriate monitoring and resuscitation in normal newborn nurseries, are presented.

A study of the sudden infant death syndrome by age

Data from 201 infants in South East Scotland certified at death as sudden infant death syndrome (SIDS) were analysed to determine whether the cases in the younger age groups at death (4-19 weeks) differed from those in the older group (19-52 weeks) on a number of background, developmental and medical variables frequently associated with SIDS in research findings. Some of the findings of the study were contrary to much of the research on SIDS in general. While some factors commonly associated with SIDS were found in both groups the 'typical' pattern presented in SIDS in the literature was more strongly associated with the older group. Marked differences between the two age groupings at death raise questions concerning those aspects of causation and aetiology that may go undetected if this distinction is not made during the analysis of SIDS information.

Apnoea and seizures

We report two infants with near miss sudden infant death syndrome events exhibiting seizure disorders after caffeine treatment, suggesting there is an infant subgroup diagnosed as near miss sudden infant death syndrome who have apnoea possibly with seizures whose seizure threshold may be lowered by central nervous system stimulants like caffeine.

Effect of sleep position on transcutaneous oxygen tension in SIDS siblings

To assess the influence of sleep position in sudden infant death syndrome siblings (SIDSS), we have studied 60 healthy SIDSS between the 1st and 3 + 4th month of life polygraphically. Infants were grouped according to postnatal age (1st, 2nd and 3 + 4th month) and sleep position (supine and prone). Transcutaneous oxygen tension (tcPO2) was continuously recorded and studied in each sleep state (active (AS) and quiet sleep (QS)) during the 1st and 2nd sleep cycle. No statistical difference could be found in tcPO2 levels as regards different sleep positions, postnatal ages (except for AS during the 2nd sleep cycle in prone and supine positions: 3 + 4th month greater than 2nd month, P less than 0.05), sleep states (except for the 1st month in supine: QS greater than AS, P less than 0.05; and 3 + 4th month in prone: AS greater than QS, P less than 0.05) or sleep cycles. tcPO2 variability was found to be significantly higher in AS as compared to QS (P less than 0.05). These results suggest that sleep position does not influence tcPO2 levels in SIDSS.

Ventilatory response to CO2 in infants with alleged sleep apnoea

Twenty-eight children whose parents reported sleep apnoea were investigated. In 15 infants apnoeic periods during sleep could be confirmed during clinical observation. Ventilatory responses to CO2 were measured in all infants, in 23 during sleep in 5 only when awake. A very wide range of CO2 sensitivities was found. In four children there was no ventilatory response or even a paradox one: a decrease in ventilation as PACO2 was increased. Two of these non-responding children died later, one still sleeps in a respirator aged three, and one developed a normal CO2 sensitivity a few months later. It is concluded that the parent's account of an apnoeic incident during sleep is not always reliable. A ventilatory response to CO2 is a useful tool with which to identify infants at risk of death, possibly related to a defective control of ventilation. The actual value of the CO2 sensitivity hardly gives any useful information, due to the wide range of "normal" reactions. No or negative ventilatory responses to CO2 seem to be indicators of high risk children, and may possibly play a role in SIDS incidents.

Carotid bodies in sudden infant death syndrome: a combined light microscopic, ultrastructural, and biochemical study

Carotid bodies (CBs) are peripheral chemoreceptors that can undergo compensatory hypertrophy and hyperplasia in some patients with chronic hypoxemia. At the Children's Hospital morphometric and biochemical analyses were done on CBs obtained at autopsy from 89 infants in the first year of life to determine if there were statistically significant differences in sudden infant death syndrome (SIDS, n = 38) compared with an age-matched control population (n = 51). Mean combined weights of CBs from SIDS victims were greater than controls in the 1- to 4-month age interval (mean = 3.4 mg, p less than 0.075) and the 4- to 8-month interval (mean = 5.0 mg, p less than 0.098) but the differences were not statistically significant (t-test, p less than 0.05). Computerized planimetry of total surface area and area occupied by "functional" parenchyma revealed no statistically significant differences. Both groups showed an equally intense degree of cytoplasmic argyrophilia of chief cells, and electron microscopy of CBs from 5 SIDS victims was indistinguishable from controls, including overall content of dense-core neurosecretory granules. There were also no significant differences in catecholamine content using liquid chromatography with electrochemical detection (SIDS n = 29, controls n = 21). These morphometric, ultrastructural, and biochemical data are not supportive for CBs having a significant role in the pathogenesis or etiology of SIDS.

Cot death in Hong Kong: a rare problem?

Cot death is very rare in Hong Kong; this may be an important contributory factor to the low postneonatal mortality (3.1 per 1000). Over the 5 years 1980-84 only 15 cases of cot death were documented by forensic pathologists--an approximate incidence of 0.036 per 1000 live births. If the incidence was similar to that in western countries (2-3 per 1000), 800-1200 cot deaths might have been expected over this period. It is argued that this rare occurrence is real and not cot death masquerading as other causes of death. It is speculated that perhaps life-style (including crowded living conditions), the practice of placing babies supine in their cots rather than prone, and a lower frequency of preterm birth could contribute.

Brainstem auditory evoked responses in infants at risk of sudden infant death

Brainstem auditory evoked responses (BAERs) were recorded from 63 near-miss Sudden Infant Death Syndrome (NMSIDS) infants, 26 siblings of SIDS (SSIBS) infants and 67 control infants between 0 and 30 weeks post-term. The majority of BAERs recorded from the NMSIDS and SSIBS infants had normal form and interpeak intervals (V-I and V-IIn) within normal limits for their age. However, 15% of these infants had interpeak intervals outside the normal range, suggesting abnormal neural function in these cases. The distributions of interpeak intervals for all NMSIDS and SSIBS infants were skewed towards longer times compared to control infants. The distributions of V-IIn intervals for both groups of at risk infants were significantly different to that of control infants. While the observations confirm that the recording of BAERs is not suitable for identifying infants at risk of SIDS, they suggest, however, that maturation of neural processing in the brainstem of these infants may be delayed.

Cardiac atrioventricular junctional tissues in hearts from infants who died suddenly

The cause of sudden infant death syndrome is not known at present. Most agree that in the majority of cases it involves primary apnea. However, cardiac abnormalities probably account for a subset of these deaths. An investigation into the structure of the atrioventricular (AV) junctional tissues of the heart would provide insight into the frequency of sudden death in infants that might result from abnormal cardiac morphology. The hearts of seven infants who died from diagnosed sudden infant death syndrome were examined by serially sectioning and studying this critical region of the heart. The hearts of these infants could be divided into three groups on the basis of their morphologic features. In the first group, represented by two cases, there were marked variations from normal, the most striking feature being the presence of accessory pathways. In the second group, represented by four cases, the AV junctional tissues were not fully mature and clusters of AV nodal and bundle cells were dispersed throughout the anulus fibrosus. In the third group, the structure of the junctional tissues was normal. There remains a distinct subset of infants who might have died suddenly and unexpectedly from cardiac abnormalities that needs to be more completely defined.

Evaluation of a one-year Swedish neonatal care population

A one-year population of 527 newborn infants treated in a Swedish neonatal unit was studied with regard to the effectiveness of the neonatal care in rate of normal survival and rate of handicaps at 3 years of age. The effectiveness could be accurately calculated in terms of survival rate being 84% and 98% of outborns and inborns respectively, and in terms of survivors without neurodevelopmental handicaps at 3 years of age being 90% and 97%, respectively. From available data on the cost of the neonatal care it could be estimated that the average annual costs for rehabilitation care for a light or moderately to a severely handicapped child were 5.8 to 11.2 times higher than in average per patient in-hospital costs during neonatal treatment. It is evident that skills in specialized neonatal care are indispensable for optimal outcome for very small low birthweight infants below 1500 g or born before 30(-32) weeks of gestation. However, in order to evaluate the return on expenditure for prevention of handicaps from the viewpoint of society adequate data on effectiveness of treatment as well as economic cost-efficiency are necessary for local and regional organization of neonatal care units.

Apnea in newborn infants: approach to management

Approximately 25% of infants with birth weights less than 1800 g or infants of about 34 weeks gestational age have an apneic episode. This, and the known high incidence of apneas in infants who subsequently are victims of sudden infant death syndrome, has led to aggressive attempts at early identification of newborns with abnormal cardio-respiratory patterns. We have found the pneumocardiogram to be effective in detecting cardio-respiratory abnormality in the newborn, and a very useful tool in the assessment of the effectiveness of pharmacologic therapy of neonatal apnea. Infants who are discharged on a home apnea monitor should be managed, utilizing a coordinated multidisciplinary team approach, that includes 24 h availability of a physician, technician, community health nurse, social worker and, when possible, a member of a parent support group. This paper presents a review of neonatal apnea and our institutional approach to its evaluation and management.

Incidence and significance of primary abnormalities of cardiac rhythm in infants at high risk for sudden infant death syndrome

The exact relationship between cardiac arrhythmias and sudden infant death syndrome (SIDS) is uncertain. Several reports have implicated both ventricular and supraventricular arrhythmias in isolated cases, but there have been no studies of the incidence or type of arrhythmias that occur in populations at risk for SIDS. Of 1699 infants at high risk for SIDS, 60 (4%) were found to have a primary cardiac arrhythmia (i.e., not associated with disordered respiration or apnea). The incidence of atrial and ventricular premature beats, supraventricular tachycardia, and Wolff-Parkinson-White syndrome was similar to the incidence found in normal infants. Primary bradycardia (defined as a heart rate less than 60 for greater than 10 s not associated with abnormal respiration) was the most common arrhythmia, occurring with a frequency and severity not seen in normal infants. Thirty-two infants experienced periodic bradycardia. In 19 of these latter infants, there were symptoms associated with these bradyarrhythmias that necessitated treatment. Heart rates as low as 20 beats/min were recorded. One infant presented with an episode of ventricular fibrillation and on further evaluation was noted to have recurrent bradyarrhythmias. In no infant was there abnormal prolongation of the QT interval. Primary bradyarrhythmias are seen at an increased incidence in infants at high risk for SIDS and may play a causal role in this syndrome. Most symptomatic infants can be adequately controlled with sympathomimetic or parasympatholytic therapy. Other cardiac arrhythmias occur at a rate similar to that in normal infants and are therefore unlikely to play a major role in SIDS.