Neonatal Hypothermia

Myron Yaster MD, Lynne G. Maxwell MD, Alan Jay Schwartz MD, MSEd

In yesterday’s PAAD, Dr. Alan Schwartz in “a remembering the classics”, reviewed the physics and methods of heat loss and conservation and the implications for pediatric anesthesia.  In today’s PAAD we review an article by Studer et al. ¹ on a single institution’s (Lurie Children’s Hospital) quality improvement project to prevent or reduce  intraoperative hypothermia.  I thought this would be a good time for these reviews as we welcome the new class of pediatric anesthesia fellows to our profession and brother/sisterhood. We, the entire editorial council of the PAAD, wish them all great success and happiness.  To quote from the knight templar in Indiana Jones and the Last Crusade: “you have chosen wisely!”   Myron Yaster MD

 

Original article

Studer A, Fleming B, Jones RC, Rosenblatt A, Sohn L, Ivey M, Reynolds M, Falciglia GH. Reducing Intraoperative Hypothermia in Infants from the Neonatal Intensive Care Unit. Pediatr Qual Saf. 2023 Jul 10;8: e655. PMID: 37434591.

As discussed in yesterday’s PAAD, newborns and young infants are at increased risk of developing hypothermia during transport to and from the OR and while in the OR because of their high body surface area to volume ratio, increased evaporative heat loss, and the absence of brown adipose tissue.  In the OR, hypothermia is increased because of open body cavities, radiation to distant walls, and the vasoplegic effects of general anesthesia.^{2, 3} Why should we care? "Hypothermic infants are at risk for infection, coagulopathy, mortality, increased oxygen consumption, and the need for cardiorespiratory support.”¹

The goal of Studer et al.’s quality improvement study was to decrease the incidence of intraoperative hypothermia. After forming a multidisciplinary, collaborative team of all of the stakeholders (NICU, OR, surgery, anesthesia, hospital QI) and using the “Model for Improvement,” the team implemented several interventions through 2 Plan-Do-Study-Act (PDSA) cycles.  After obtaining buy-in from all of the stake holders, they standardized “(1) temperature monitoring with a preoperatively placed rectal (unless contraindicated) continuous temperature probe (CTP)”, (2) the transport process whereby infants were transported by an anesthesia provider and NICU nurse in a thermal bed/shuttle (in servo mode) and a thermos reflective cap, and (3) warming equipment used in the OR including a forced air warmer underneath the patient, a portable heat lamp during infant exposure, and warmed betadine, fluid, and irrigation solutions.”¹ Patients who underwent bedside surgery or interventional radiologic procedures were excluded in this process and study.

What did they find? “By standardizing temperature monitoring, the transport process to the OR, and intraoperative warming, the percentage of infants experiencing hypothermia upon OR arrival and at any point during the operation decreased from 48.7% to 6.4% and 67.5% to 37.4%, respectively. Upon return to the NICU, the percentage of infants experiencing postoperative hypothermia decreased from 5.8% to 2.1%, while postoperative hyperthermia increased from 0.8% to 2.6%.”¹

This quality improvement study demonstrates once more that, in anesthesia practice, standardization and minimizing variability improves outcomes.  Further, as an aggressive heat conservationist using plastic bags to reduce evaporative heat loss⁴, I (MY) learned the hard way, that aggressive prevention of hypothermia may lead, as seen in this study, to an increase in HYPERthermia on arrival to the NICU.  Indeed, Studer et al. note “further decreasing intraoperative and postoperative hypothermia may not be possible without further increasing postoperative hyperthermia.”¹

Please send your thoughts about these 2 PAADs to Myron who will post in the Friday Reader response.

References

1.           Studer A, Fleming B, Jones RC, et al. Reducing Intraoperative Hypothermia in Infants from the Neonatal Intensive Care Unit. Pediatric Quality & Safety. 2023;8(4):e655. doi:10.1097/pq9.0000000000000665

2.           Sessler DI. Perioperative heat balance. Anesthesiology. 2/2000 2000;92(2):578-596. Not in File.

3.           Sessler DI. Temperature regulation. In: Gregory GA, ed. Pediatric anesthesia. 3d ed. Churchill Livingstone; 1994:47-82:chap 3.

4. Rowe MI, Taylor M. Transepidermal Water Loss in the Infant Surgical Patient. Journal of Pediatric Surgery, 1981; 16 (6); 878-881.