Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats.
General anesthesia causes hypothermia by impairing normal thermoregulatory mechanisms. When using inhalational anesthetic agents, Redistribution of warm blood from the core to the periphery is the primary mechanism in the development of hypothermia and begins following induction of anesthesia. Raisi...
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doaj-f45a581c35ce4f26839869121267939d2021-03-03T21:32:31ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-01153e021972210.1371/journal.pone.0219722Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats.Maxime RufiangeVivian S Y LeungKeith SimpsonDaniel S J PangGeneral anesthesia causes hypothermia by impairing normal thermoregulatory mechanisms. When using inhalational anesthetic agents, Redistribution of warm blood from the core to the periphery is the primary mechanism in the development of hypothermia and begins following induction of anesthesia. Raising skin temperature before anesthesia reduces the temperature gradient between core and periphery, decreasing the transfer of heat. This prospective, crossover study (n = 17 adult male and female SD rats) compared three treatment groups: PW1% (pre-warming to increase core temperature 1% over baseline), PW40 (pre-warming to increase core temperature to 40°C) and NW (no warming). The PW1% group was completed first to ensure tolerance of pre-warming. Treatment order was then randomized and alternated after a washout period. Once target temperature was achieved, anesthesia was induced and maintained with isoflurane in oxygen without further external temperature support. Pre-warming was effective at delaying the onset of hypothermia, with a significant difference between PW1% (12.4 minutes) and PW40 (19.3 minutes, p = 0.0044 (95%CI -12 to -2.2), PW40 and NW (7.1 minutes, p < 0.0001 (95%CI 8.1 to 16.0) and PW1% and NW (p = 0.003, 95%CI 1.8 to 8.7). The rate of heat loss in the pre-warmed groups exceed that of the NW group: PW1% versus NW (p = 0.005, 95%CI 0.004 to 0.027), PW40 versus NW (p < 0.0001, 95%CI 0.014 to 0.036) and PW1% versus PW40 (p = 0.07, 95%CI -0.021 to 0.00066). Pre-warming alone confers a protective effect against hypothermia during volatile anesthesia; however, longer duration procedures would require additional heating support.https://doi.org/10.1371/journal.pone.0219722 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Maxime Rufiange Vivian S Y Leung Keith Simpson Daniel S J Pang |
spellingShingle |
Maxime Rufiange Vivian S Y Leung Keith Simpson Daniel S J Pang Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. PLoS ONE |
author_facet |
Maxime Rufiange Vivian S Y Leung Keith Simpson Daniel S J Pang |
author_sort |
Maxime Rufiange |
title |
Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. |
title_short |
Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. |
title_full |
Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. |
title_fullStr |
Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. |
title_full_unstemmed |
Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. |
title_sort |
pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2020-01-01 |
description |
General anesthesia causes hypothermia by impairing normal thermoregulatory mechanisms. When using inhalational anesthetic agents, Redistribution of warm blood from the core to the periphery is the primary mechanism in the development of hypothermia and begins following induction of anesthesia. Raising skin temperature before anesthesia reduces the temperature gradient between core and periphery, decreasing the transfer of heat. This prospective, crossover study (n = 17 adult male and female SD rats) compared three treatment groups: PW1% (pre-warming to increase core temperature 1% over baseline), PW40 (pre-warming to increase core temperature to 40°C) and NW (no warming). The PW1% group was completed first to ensure tolerance of pre-warming. Treatment order was then randomized and alternated after a washout period. Once target temperature was achieved, anesthesia was induced and maintained with isoflurane in oxygen without further external temperature support. Pre-warming was effective at delaying the onset of hypothermia, with a significant difference between PW1% (12.4 minutes) and PW40 (19.3 minutes, p = 0.0044 (95%CI -12 to -2.2), PW40 and NW (7.1 minutes, p < 0.0001 (95%CI 8.1 to 16.0) and PW1% and NW (p = 0.003, 95%CI 1.8 to 8.7). The rate of heat loss in the pre-warmed groups exceed that of the NW group: PW1% versus NW (p = 0.005, 95%CI 0.004 to 0.027), PW40 versus NW (p < 0.0001, 95%CI 0.014 to 0.036) and PW1% versus PW40 (p = 0.07, 95%CI -0.021 to 0.00066). Pre-warming alone confers a protective effect against hypothermia during volatile anesthesia; however, longer duration procedures would require additional heating support. |
url |
https://doi.org/10.1371/journal.pone.0219722 |
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