Brazilian Journal of Anesthesiology
Brazilian Journal of Anesthesiology
Original Investigation

Forced-air warming and continuous core temperature monitoring with zero-heat-flux thermometry during cesarean section: a retrospective observational cohort study

Aquecimento com ar forçado e monitoramento contínuo da temperatura central com termometria de fluxo de calor zero durante a cesariana: um estudo de coorte observacional retrospectivo

Laurentiu Marin, Jan Höcker, André Esser, Rainer Terhorst, Axel Sauerwald, Stefan Schröder

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Over 30% of parturients undergoing spinal anesthesia for cesarean section become intraoperatively hypothermic. This study assessed the magnitude of hypothermic insult in parturients and newborns using continuous, high-resolution thermometry and evaluated the efficiency of intraoperative forced-air warming for prevention of hypothermia.

111 parturients admitted for elective or emergency cesarean section under spinal anesthesia with newborn bonding over a 5-month period were included in this retrospective observational cohort study. Patients were divided into two groups: the passive insulation group, who received no active warming, and the active warming group, who received convective warming through an underbody blanket. Core body temperature was continuously monitored by zero-heat-flux thermometry and automatically recorded by data-loggers. The primary outcome was the incidence of hypothermia in the operating and recovery room. Neonatal outcomes were also analyzed.

The patients in the passive insulation group had significantly lower temperatures in the operating room compared to the actively warmed group (36.4°C vs. 36.6°C, p = 0.005), including temperature at skin closure (36.5°C vs 36.7°C, p = 0.017). The temperature of the newborns after discharge from the postanesthetic care unit was lower in the passive insulation group (36.7°C vs 37.0°C, p = 0.002); thirteen (15%) of the newborns were hypothermic, compared to three (4%) in the active warming group (p < 0.01).

Forced-air warming decreases perioperative hypothermia in parturients undergoing cesarean section but does not entirely prevent hypothermia in newborns while bonding. Therefore, it can be effectively used for cesarean section, but special attention should be given to neonates.


Cesarean section;  Core temperature;  Hypothermia;  Newborn bonding;  Zero-heat-flux


Justificativa: Mais de 30% das parturientes submetidas à raquianestesia para cesariana tornam-se hipotérmicas no intraoperatório. Este estudo avaliou a magnitude do insulto hipotérmico em parturientes e recém-nascidos usando termometria contínua de alta resolução e avaliou a eficiência do aquecimento com ar forçado intraoperatório para prevenção de hipotermia. Métodos: 111 parturientes admitidas para cesariana eletiva ou de emergência sob raquianestesia com ligação do recém-nascido por um período de 5 meses foram incluídas neste estudo de coorte observacional retrospectivo. Os pacientes foram divididos em dois grupos: o grupo de isolamento passivo, que não recebeu aquecimento ativo, e o grupo de aquecimento ativo, que recebeu aquecimento convectivo por meio de um cobertor sob o corpo. A temperatura corporal central foi monitorada continuamente por termometria de fluxo de calor zero e registrada automaticamente por registradores de dados. O desfecho primário foi a incidência de hipotermia na sala de cirurgia e recuperação. Os resultados neonatais também foram analisados. Resultados: Os pacientes do grupo de isolamento passivo apresentaram temperaturas significativamente mais baixas na sala de cirurgia em comparação com o grupo aquecido ativamente (36,4°C vs. 36,6°C, p = 0,005), incluindo temperatura no fechamento da pele (36,5°C vs 36,7°C C, p = 0,017). A temperatura dos recém-nascidos após a alta da sala de recuperação pós-anestésica foi menor no grupo isolamento passivo (36,7°C vs 37,0°C, p = 0,002); treze (15%) dos recém-nascidos estavam hipotérmicos, comparados a três (4%) no grupo de aquecimento ativo (p < 0,01).


Cesariana; Temperatura do núcleo; Hipotermia; Ligação do recémnascido; Fluxo de calor zero


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