Comparison of peri‐operative core temperature in obese and non‐obese patients*

Abstract

SummaryOur aim was to compare peri-operative core temperatures and the incidence of hypothermia in obese and non-obese women with active forced-air warming. Twenty female patients scheduled for abdominal surgery were allocated to two groups according to body mass index. Ten obese (30.0-34.9 kg.m )2) and 10 non-obese (18.5-24.9 kg.m ) women received forced-air warming on their lower limbs. At the end of surgery, the mean (SD) core temperatures were 36.7 (0.5)°C in the obese group and 36.0 (0.6)°C in the non-obese group (p < 0.001). Only in the non-obese group was there a significant decrease in the intra-operative core temperature values (p < 0.001). The incidences of intra-operative hypothermia were lower in the obese group (10%) compared with non-obese group (60%; p = 0.019). In the postoperative recovery phase, the mean (SD) core temperature data were higher in the obese group than in the nonobese group (36.2 (0.4) vs 35.6 (0.5)°C, respectively (p < 0.001)). In conclusion, obese female patients have higher perioperative core temperature and a lower incidence of hypothermia compared with non-obese female patients during abdominal surgery with active forced-air warming. Accepted: 21 August 2012Unintentional peri-operative hypothermia (core temperatures between 34.5 and 35.9°C) often leads to adverse outcomes, including cardiac events secondary to sympathetic nervous system activation [1], surgicalwound infections and prolonged hospitalisation [2], coagulopathy and increased blood loss [3], impaired drug metabolism, delayed postoperative recovery period [4,5] and shivering [6]. Therefore, maintaining perioperative normothermia reduces morbidity [1][2][3] and the use of peri-operative warming devices has become routine.The prevalence of obesity has increased markedly worldwide in recent years [7]. In clinical practice, body mass index (BMI) is used to estimate the degree of obesity, which is classified in three levels: grade 1 (BMI from 30.0 to 34.9 kg.m ) [8]. The prevalence of grade-1 obesity is higher among both female and male obese populations than are the other grades [8]. Obese patients are more likely to vasoconstrict in cooler environments [9], have reduced heat redistribution from core to peripheral tissue after

Tympanic and Temporal Thermometry in Hypothermia Assessment for Adult in Intraoperative Abdominal Surgery

“…By using measures of oral and esophageal temperatures, different thermometry than that used in this study, obese women were shown to have a higher perioperative temperature and a lower incidence of hypothermia when compared to non-obese women. 17 In the USA, one study comparing oral, temporal and bladder thermometry supported a BMI below 30 kg/m 2 as a risk factor for hypothermia. 13 In the present study, hypothermia was identified in patients with ASA II and III, that is, those with comorbidities.…”

The impact of body mass index on patient survival after therapeutic hypothermia after resuscitation

“…In these studies, obesity has been associated with longer duration of time to reach target temperature; although in one study there was no difference in survival. [11,12,21,22] It is acknowledged that fewer obese patients presented with ventricular fibrillation than non-obese patients, which may affect the findings. Nevertheless, we show contemporary results of patients stratified by BMI with similar percentages of non-shockable rhythms, ventricular tachycardia, and similar achievement of target temperatures; obesity was associated with reduced survival.…”

“…[9,10] While there is growing medical and surgical literature showing that the time to target temperature takes longer for obese patient, little is known about the impact of obesity on survival post therapeutic hypothermia. [11–13] We hypothesized that body mass index (BMI) ≥30 kilogram/meter squared (kg/m 2 ) is associated with higher risk of mortality than BMI <30kg/m 2 after therapeutic hypothermia for cardiac arrest.…”

Comparison of warming methods for core temperature preservation during total knee arthroplasty using a pneumatic tourniquet

“…The BMI of group 4 was lower than that of the other three groups. Fernandes et al [27] reported that the average core body temperature is maintained during the perioperative period at a higher level with air warmers in obese patients than in normal patients. Not only does thermal conduction occur more slowly in obese patients, but also the heat is produced to a greater degree by sympathetic nervous system activation through leptin secreted from fat cells [28,29].…”