Hypoxic and Hypercapnic Events in Young Infants During Bed-Sharing SCH Journal Club Elspeth Ferguson ST5 Paediatrics

Aim To determine if there is any difference in physiological parameters of bed-sharing and non-bed sharing infants during sleep

Objectives To search the literature for relevant articles Select a relevant paper to discuss Determine validity and reliability of paper in answering clinical question Discuss how this information may affect our clinical practice

What we know about SIDS 300 deaths/year Risk factors –Prematurity –LBW –Smoking –Sleep environment

What is the mechanism of SIDS Not well understood Presumed particular vulnerability ?Upper airway compromise ?Hypoxia ?Abnormalities of brainstem function

Current Advice for Parents Back to sleep Feet to foot Don’t smoke Don’t share a bed Baby to sleep in your room for first 6 months Don’t let your baby get too hot Breastfeed ?dummy

Clinical Question P Infants I Bed-sharing (co-sleeping) C Cot-sleeping (non co-sleeping) O Hypoxia/Hypercapnia Study design Case-control study

Hypoxic and Hypercapnic Events in Young Infants During Bed-Sharing Baddock, S.A., Galland, B.C., Bolton, D.P.G., Williams, S.M & Taylor, B.J Pediatrics :

Methods 40 bed-sharing infants, 40 cot-sharing infants Monitoring over 2 nights in home environment –Video recordings –Physiological recordings –Maternal questionnaire for demographic data

Outcome Measures Desaturation events –<90% ≥1second Re-breathing events –CO2 >3% CO2 exposure –CO2 >2/3/4% ≥ 3 seconds

CASP Analysis 1. Did the study address a clearly focused issue? ✓ Yes 2. Did the authors use an appropriate method to answer their question? ✓ Yes

3. Were the cases recruited in an acceptable way? Media advertising & Postnatal groups –Who responds to adverts? –Who attends postnatal groups? –?incentives

4. Were the controls recruited in an acceptable way? Postnatal ward Different group from bed-sharing individuals – why? Matched for age and season of study

5. Was the exposure accurately measured to minimise bias? Bed-sharing at least 5 hr per night ?how this was determined Regularly Blinding not possible –?infants affected by monitoring equipment –?mother’s actions altered

6. Confounding factors Matched for age and season of recruitment Smoking Alcohol Drug use Birth weight Gestation Socioeconomic status Method of feeding

What are the results? & How precise are they? Desaturation events –BS 255 VS CS 123 –Characteristics of events comparable –Mean events per infant BS 6.8 (0-44) VS CS 3.1 (0- 16) –Relative risk of event 2.17(1.75 – 2.69) –When adjusted for temperature RR 1.54 ( ) –1 degree increase in temperature = 60% increase in desaturation events (95% CI 31-96)

What are the results? & How precise are they? Rebreathing events –Infants experiencing episodes BS 22 VS CS 1 –Median rebreathing per night = 19min –Majority associated with head covering –Increases in heart rate and respiratory rate observed

What are the results? & How precise are they? CO2 exposure –Infants exposed to ≥ 2% CO2 BS 27 VS CS 2

9. Do you believe the results Significantly more desaturations in bed- sharing infants Temperature seems to have a key role Significance values for raised CO2 and rebreathing episodes unclear

10. Can the results be applied to the local population? Majority of European descent Socio-economic status or group Rates of breast-feeding

11. Do the results of this study fit with other available evidence? Suggest sleep ‘events’ more frequent in bed-sharing Highlights importance of temperature regulation May suggest a mechanism by which bed- sharing leads to an increased risk of SIDS

Summary Bed-sharing infants experience more episodes of desaturation, rebreathing and raised CO2 exposure than cot-sleeping infants BUT are these episodes of concern?