Contact mattress to prevent heat loss in neonatal and paediatric surgery

Perioperative Hypothermia in Children

Background: First described by paediatric anaesthesiologists, perioperative hypothermia is one of the earliest reported side effects of general anaesthesia. Deviations from normothermia are associated with numerous complications and adverse outcomes, with infants and small children at the highest risk. Nowadays, maintenance of normothermia is an important quality metric in paediatric anaesthesia. Methods: This review is based on our collection of publications regarding perioperative hypothermia and was supplemented with pertinent publications from a MEDLINE literature search. Results: We provide an overview on perioperative hypothermia in the paediatric patient, including definition, history, incidence, development, monitoring, risk factors, and adverse events, and provide management recommendations for its prevention. We also summarize the side effects and complications of perioperative temperature management. Conclusions: Perioperative hypothermia is still common in paediatric patients and may be attributed to their vulnerable physiology, but also may result from insufficient perioperative warming. An effective perioperative warming strategy incorporates the maintenance of normothermia during transportation, active warming before induction of anaesthesia, active warming during anaesthesia and surgery, and accurate measurement of core temperature. Perioperative temperature management must also prevent hyperthermia in children.

Prevention of intraoperative hypothermia in neonates and infants: results of a prospective multicenter observational study with a new forced-air warming system with increased warm air flow

OBJECTIVES

Neonates and infants are at the highest risk of developing perioperative hypothermia. A number of methods to prevent hypothermia during pediatric anesthesia are in use, and despite the fact that conventional forced-air warmers are the most effective devices, they are not always sufficient enough to maintain body temperature. Therefore, recently a new forced-air warming system with an increased warm air flow was introduced to the market.

AIM

The aim of this study was to evaluate this new forced-air warming system in neonates and infants during pediatric anesthesia. We hypothesized that the new blanket alone is sufficient enough to prevent neonates and infants from intraoperative hypothermia.

METHODS

Neonates and infants (body weight <10 kg) were enrolled in this prospective multicenter observational study. After admission to the operating room, the children were placed on the new forced-air warming blanket. Body temperature was measured continuously until admission to the recovery room or pediatric intensive care unit (PICU).

RESULTS

Hundred and nineteen children with a median body weight of 4.1 kg (range: 0.7-9.8) were enrolled and received their intended treatment. Median body temperature at the induction of anesthesia was 36.5 °C (range: 35.3-38.2 °C) and increased with the length of the operation up to 37.8 °C (37.1-38.2 °C) after 180 min. Median body temperature after admission to the recovery room or PICU was 37.2 °C (36.0-38.6 °C) and remained significantly above baseline (P < 0.05).

CONCLUSIONS

The new forced-air warming system as a sole warming device is effective in preventing perioperative hypothermia during pediatric anesthesia in neonates and infants.

Assessment of the efficiency of warming devices during neonatal surgery

This study assessed the relative efficiency of different warming devices (surgical sheets covering the body and a tubegauze on the head, forced-air warming, warming mattress) commonly used to prevent body hypothermia during neonatal surgery. Dry heat losses were measured from a thermal manikin, which simulated a low-birth-weight neonate of 1,800 g. The manikin's surface temperatures (35.8 degrees C) corresponded to those of neonates nursed in closed incubators. Experiments were performed in a climatic chamber at an ambient temperature of 30 degrees C, as commonly found in operating theatres. The supine manikin was naked or covered with operative sheets with a 5x5 cm aperture over the abdomen. Its head could be covered by a tube-gauze. Additional warming was provided by conduction through a warming mattress (surface temperature, 39 degrees C) and/or by convection (Bair Hugger, forced-air temperature 38 degrees C). Covering the manikin with surgical sheets decreased the dry heat loss by 10.4 W. Additional forced-air warming was more efficient than the warming mattress to reduce the total dry heat loss (6.8 W vs 2.1 W). Heat losses were reduced by 7.9 W when combining the warming mattress and Bair Hugger. The heat loss from the head of the covered manikin was reduced from 4.5 W to 3.9 W when the head was covered with the tubegauze. Our data indicate that forced-air warming is more effective than conductive warming in preventing neonatal hypothermia during abdominal operations.

Neonatal cleft lip repair in Ayrshire; a contribution to the debate

Neonatal cleft lip repair has been the normal practice in Ayrshire, Scotland, for the last 10 years. The surgical results are briefly presented. Anaesthetic and paediatric considerations are discussed. Assuming careful preoperative assessment is made, the procedure carries minimal morbidity, can give good results and is believed to offer distinct advantages to the parents and child.