TRANSITIONAL HYPOTHERMIA IN

PRETERM NEWBORNS

Dr Prakash.I

INTRODUCTION Important factor influencing newborn Health. It remains a significant challenge, especially

in the perinatal care of preterm infants. Clinical experience suggests that

hypothermia remains An ongoing problem, especially among ELBW

infants, even for those born in Level III perinatal centers.

Preterm delivery less than 28 weeks or less than 1000 g occurs in 1–2% of all deliveries, but accounts for the large majority of neonatal morbidity and mortality.

Therefore, this topic deserves special attention.

DEFINITION

Newborn infant has immature thermo-regulation.

In 1997, acc to WHO definitions of normothermia and hypothermia:

Normal range: 36.5–37.51C Cold stress: 36.0–36.51; cause for

concern Moderate hypothermia: 32.0–36.0 Severe hypothermia: less than 32.0

CAUSES

Hypothermia can be a problems in Delivery room resuscitation efforts During transport of the preterm infant

to the NICU During certain NICU admitting

procedures.

PREVENTION STRATEGIES Perinatal hypothermia to be avoided except in

those who have sustained a significant hypoxic-ischemic insult.

In 2006, the AAP’ and AHA Neonatal Resuscitation Program (NRP) recommended-the first postnatal temperature should be an axillary temperature of approximately 36.5 C.

NRP recommends - ‘temperature must be monitored closely due to risk of hyperthermia during or after ischemia is associated with progression of cerebral injury. The goal is to achieve normothermia and avoid iatrogenic hyperthermia’.

Continuous temperature monitoring -initiated as soon as possible after the birth of the preterm infants.

NRP recommended- ‘when delivery of a preterm baby is anticipated, the temperature of the room should be increased’, and to ‘pre-heat the radiant warmer by turning it on well before birth, use a head cap, and if the baby is born at less than 28 weeks gestation, consider placing him, below the neck, in a reclosable polyethylene bag, without first drying the skin.

American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) and WHO works together for delivery room temperatures with hospital leaders and managers of Labor and Delivery services.

ASHRAE recommends- Single room labor-delivery-recovery-postpartum temperature : 75 °F, Standard patient room temperature of 75 °F Recovery room temperature : 75 °F Nursery temperature : 75 °F. The guidelines state that Delivery Room

temperature should never be ≤68 °F.

Recommendations from American Institute of Architects (AIA), WHO and Recommended Standards for Newborn ICU- Prevention of hypothermia is also enhanced by use of weighing scales built into warmers and appropriate attention to adequate warming mechanisms of transport incubators.

Important aspect- staff education on the problem of neonatal hypothermia and the use of preventive strategies, especially in the ELBW infant.

CURRENT DATA: PREVALENCE OF HYPOTHERMIA AMONG LOWBIRTH WEIGHT INFANTS

AAP colleagues shared the following quality improvement data regarding hypothermia (defined as a temperature ≤ 36.41C or ≤ 97.61F) at admission to their units from the delivery room within 30 min of birth (Table 2).

Data show a high prevalence of hypothermia among LBW preterm infants, with reported incidence of at least 25% among infants <2500 g birth weight, and ≥ 56% in infants <750 g

RECOMMENDATIONS Hypothermia a preventable event in nearly all

infants, even in ELBW Deserves special attention –as associated with

significant morbidity and mortality. Multicenter clinical trials required to establish

best practices for prevention of hypothermia. The delivery room temperature should be at

or higher than that recommended for the labor-delivery-recovery-postpartum, patient room, recovery room and nursery, especially for the preterm infant.

Recommendation: every delivery room should have individual thermostat and humidity control, as needed for preterm deliveries.

Delivery room temperatures and humidity should be documented, and infant’s temperature should be recorded as soon as possible after birth and every 10–15 min thereafter until continuous temperature monitoring has been established.

Monitoring consider the possibility of extremes in body temperature in either direction among ELBW infants.

Over-warming can occur and is equally dangerous.

The set points for delivery rooms are consensus-based and not evidence-based.

Acc to WHO, ‘adults should not determine the delivery room temperature according to their own comfort’.

Discussions with members of the obstetrical team will be necessary to effect this change in the delivery room, especially during operative deliveries when gowning is used.

It should be remembered that warming the delivery room above 72 F will be necessary in <2% of deliveries.

A dedicated room for newborn resuscitation adjacent to the delivery room in which ambient temperature can be well controlled.

SUMMARY Is a significant concern, especially among extremely preterm

infants. One study- hypothermia among preterm newborns born at or

below 1500 g varies from 31 to 78%. Clinical trials data currently are lacking.

Currently, we recommend the NRP and ASHRAE recommendations for delivery room temperature management

The goal is to achieve normothermia and avoid iatrogenic hyperthermia.

The AAP Committee on Fetus and Newborn are working together to assess the magnitude of this problem and support institution of measures to prevent hypothermia among preterm neonates.

Thank you