Related Experiment Videos
Anesthesia blocks nonshivering thermogenesis in the neonatal rabbit
C T Albanese1, B M Nour, M I Rowe
1Department of Pediatric Surgery, Children's Hospital of Pittsburgh, PA 15213-2583.
Journal of Pediatric Surgery
|August 1, 1994
Summary
Neonatal nonshivering thermogenesis (NST) is impaired by many anesthetics and paralyzing agents. However, stopping anesthesia during cold exposure significantly boosts metabolic activity (oxygen consumption) in neonates.
Area of Science:
- Neonatal physiology
- Anesthesiology
- Thermoregulation
Background:
- Nonshivering thermogenesis (NST) is a critical neonatal response to cold, involving brown fat activation.
- Standard neonatal surgical practice involves warming to conserve energy.
- The impact of anesthesia and paralysis on neonatal NST is not fully understood.
Purpose of the Study:
- To characterize the neonatal thermogenic response to cold exposure under various anesthetic and paralyzing agents.
- To investigate the effect of anesthetic withdrawal on metabolic activity during cold exposure.
Main Methods:
- Newborn rabbits (1-7 days old) were mechanically ventilated and received various agents (metocurine, pancuronium, curare, fentanyl, nitrous oxide, halothane) or were spontaneously breathing (controls).
- Oxygen consumption (VO2) was measured at thermoneutrality (39°C) and cold exposure (25°C).
- An additional study examined VO2 during continuous halothane vs. halothane withdrawal during cold exposure.
Main Results:
- Controls and metocurine-treated animals showed increased VO2 during cold exposure.
- Curare, pancuronium, fentanyl, nitrous oxide, and halothane inhibited the VO2 response to cold.
- Halothane withdrawal during cold exposure caused a significant increase in VO2, returning to baseline upon rewarming.
Conclusions:
- Common anesthetic and paralyzing agents suppress neonatal thermogenic responses to cold.
- Anesthetic cessation in a cold environment can elicit a substantial increase in neonatal metabolic activity.