Update on intrapartum fetal pulse oximetry

This article examines the current status of fetal pulse oximetry (FPO) as a means of intrapartum assessment of fetal wellbeing. FPO has been developed to a stage where it is a safe and accurate indicator of intrapartum fetal oxygenation. In general, sliding the FPO sensor along the examiner's fingers and through the cervix, to lie alongside the fetal cheek or temple is easy The recent publication of a randomised controlled trial (RCT) of FPO versus conventional intrapartum monitoring has validated its use to reduce caesarean section rates for nonreassuring fetal status. An Australian multicentre RCT is currently underway. Maternal satisfaction rates with FPO are high. FPO may be used during labour when the electronic fetal heart rate trace is nonreassuring or when conventional monitoring is unreliable, such as with fetal arrhythmias. If the fetal oxygen saturation (FSpO(2)) values are < 30%, prompt obstetric intervention is indicated, such as fetal scalp blood sampling or delivery FSpO(2) monitoring should not form the sole basis of intrapartum fetal welfare assessment. Rather, the whole clinical picture should be considered.

Rebreathing potential of infant mattresses and bedcovers

Objective : To establish the CO2 dispersion and retention properties of some mattresses and bed coverings commercially available in Australia. Methods : Five mattresses were studied in (i) an in vivo model in which an infant's head was covered by a headbox, rebreathing was allowed to occur, and the final steady state CO2 concentration was measured; and (ii) an in vitro model in which 5% CO2 in a headbox was allowed to disperse, and the time taken for the concentration to reach 1% was measured. Five types of bedcover were studied in (i) an in vivo model in which an infant's head was covered by a bedcover and the final steady state CO2 concentration was measured; and (ii) an in vitro model in which 5% CO2 under a bedcover was allowed to disperse, and the time taken for the concentration to reach 1% was measured. Results : The steady state CO2 concentrations ranged from 0.6% to 3.0% for the mattresses (P < 0.05). The time for CO2 to disperse ranged from 5.5 min to 30.4 min (P < 0.05). Steady state CO2 concentrations ranged from 2.5% to 3.6% for the bedcoverings (P > 0.05). The time for CO2 to disperse ranged from 5.4 min to 7.7 min (P > 0.05). Conclusions : Some commercial cot mattresses and bedcoverings allow high concentrations of CO2 to accumulate in rebreathing environments. Some mattress types studied were more diffusive to CO2 , whereas there was no difference between the bedcovers studied. This may have implications for vulnerable infants at risk of sudden infant death syndrome.