Biomedical subjects

R Wigfield

Publications and source records attributed to R Wigfield.

3 recordsLinked to original sources

PubMed1994

SIDS: risk reduction measures.

Increasing public awareness of the prone sleeping position, maternal smoking and overheating as potentially avoidable risk factors for the sudden infant death syndrome (SIDS) has been accompanied by a dramatic reduction in mortality. The results of two population based studies of SIDS in Avon are compared; the first one occurred before these risk factors were widely known and during the second study there was a gradual increase in publicity. Between the studies the prevalence of prone sleeping in the control populations fell significantly from 60% to 28% and almost all of the reduction in SIDS mortality (3.5 to 1.7 per thousand live births) could be attributed to this change. Other changes were also found: the seasonal pattern of incidence was lost, the proportion of expreterm babies increased and the male predominance was accentuated. The relative importance of smoking and bottle feeding appeared to increase whereas the odds ratios for heavy wrapping and overnight heating were no longer significantly elevated. Small numbers limit the significance of these individual variations but demonstrate that changes are occurring. Local and national public health campaigns have been launched in the UK and abroad to encourage infant care practices that reduce the risk of SIDS. Monitoring the effectiveness of these campaigns is important and may allow new risk factors to be identified which could in turn be targeted in future preventative campaigns. Significant reductions in mortality have followed these initial campaigns but in order to maintain them the message must be regularly renewed using an appropriate approach and effective channels of communication to target high risk families within the community.

Bottle Feeding↗

PubMed1993

Interactions between thermoregulation and the control of respiration in infants: possible relationship to sudden infant death.

In summary, there is evidence that developmental changes in respiratory control and in thermoregulation have effects upon each other. Theoretically, such effects could give rise to failure of the respiratory system and there is some circumstantial evidence to support the concept that on occasions such interactions may be of importance in sudden unexpected death in infancy. Future research in this area should focus on the nature of the interactions between thermoregulation and respiration, and on the effects of infection and infection-related mediators on those interactions.

Body Temperature↗

PubMed1992

Development of thermoregulation in infancy: possible implications for SIDS.

Over the first three months of life the infant's metabolic rate rises, which, together with the rise in ratio of mass to surface area, means that the net heat loss per unit surface area is 50% higher in a 3 month old infant than in a neonate. This, together with the thicker layer of subcutaneous fat and more effective peripheral vasomotor response to cold in a 3 month old infant, means that thermal balance is shifted in favour of heat conservation. The head is the site of 40% of heat production and of up to 85% of heat loss in an infant in bed: covers rising up over the head could therefore result in acute thermal imbalance with a rise in brain temperature not necessarily accompanied by a rise in body temperature. In animal studies relatively small changes in hypothalamic temperature have profound effects on the control of respiration. Alternatively, a rise in metabolic rate (from an acute infection, for example) could result in a significant change in thermal balance. There is anecdotal evidence that heat stress may be associated with sudden infant death or with severe hypoventilation. In the Avon studies infants with SIDS, particularly those over 70 days of age, were more heavily wrapped and were more likely to have had the heating on all night than control infants matched for age, date, and neighbourhood. There was no significant excess of viral infections in the infants with SIDS, but those who had virus infections were much more heavily wrapped than control infants with similar infections, suggesting that the combination of heavy wrapping and virus infection may be more important than either factor alone. There is, therefore, some physiological evidence that infants of 2 to 3 months of age may be more vulnerable to heat stress than younger infants, and limited evidence, from clinical studies, that this may occur and be associated with some sudden deaths. The precise contribution of thermal stress and the mechanism by which it could cause death remain unclear.

Body Temperature Regulation↗