Mean Core Body Temperature Research Articles

Temperature Dynamics in Early Pregnancy: Implications for Improving In Vitro Fertilization Outcomes

In assisted reproductive technology, in vitro fertilization involves cultivating embryos in an artificial environment, often yielding lower-quality embryos compared to in vivo conditions. This study investigated core body temperature (CBT) fluctuations in mice during early pregnancy. Their CBT was measured with a high temporal resolution to identify the optimal thermal conditions during the first five days post-fertilization, aiming to improve in vitro culture conditions. Data were collected from 12 female mice, with 8 becoming pregnant, using temperature loggers every minute for 11 days. Data analysis focused on trends, circadian rhythms, frequency components, and complexity using multiscale entropy (MSE). The results for the pregnant mice showed a mean CBT increase from 37.23 °C to 37.56 °C post-mating, primarily during the light phase, with a significant average rise of 0.58 °C. A Fourier analysis identified dominant 24, 12, 8, and 6 h components, with the 24 h component decreasing by 57%. Irregular fluctuations decreased, and MSE indicated increased complexity in the CBT time series post-mating. These results suggest that reducing diurnal temperature variations and maintaining a slightly elevated mean CBT of approximately 37.5 °C, with controlled minor fluctuations, may enhance embryo quality in pregnant mice. This study provides a reference for temperature regulation in embryo culture, improving embryo quality by aligning in vitro conditions with the natural thermal environment of the fallopian tubes.

Interventions to prevent hypothermia in extremely preterm low-weight infants undergoing cardiac catheterisation

BackgroundIn January 2019, a new device called the Amplatzer Piccolo Occluder was approved by the US Food and Drug Administration for percutaneous closure of patent ductus arteriosus in infants weighing...

Effects of dietary L-citrulline supplementation on nitric oxide synthesis, immune responses and mitochondrial energetics of broilers during heat stress

L-Citrulline is a non-protein amino acid that promotes arginine recycling and muscle protein synthesis. This study investigated whether L-citrulline can exert these functions in heat-stressed chickens. Arbor acre broilers were fed either basal diets (Control) or basal diets supplemented with 1% L-citrulline (L-Cit). At 28 d old, broilers were subjected to two environmental temperatures, 35 °C for 8 h/d (HS) or 24 °C for 24 h/d (TNZ) for 2 weeks. The experiment was designed as a 2 by 2 factorial arrangement. Results showed that HS increased the core body temperature (CBT) and rectal temperature of broilers compared to the TNZ condition. The CBT and mean CBT decreased by ∼0.5oC in TNZ + L-Cit broilers compared to the TNZ + Control group (P < 0.05). L-Cit supplementation at TNZ significantly (P < 0.05) lowered the plasma malondialdehyde content but this was increased during HS. Exposure to HS significantly (P < 0.05) elevated plasma malondialdehyde compared to TNZ condition. Plasma immunoglobulin A, G, and M were increased (P < 0.05) by TNZ + L-Cit compared to the TNZ + Control group. Plasma nitric oxide and endothelial nitric oxide synthase (NOS) activity was increased during HS, whereas the total and inducible NOS enzymes were decreased. In addition, L-Cit supplementation increased both the inducible and endothelial NOS isoforms (P < 0.05). The mRNA expression of peroxisome proliferator-activated receptor γ coactivator 1-α, avian uncoupling protein, cytochrome C oxidase subunit 3, and ATP synthase F1 subunit beta (ATP5β) in the breast muscle were downregulated (P < 0.05) during HS. However, L-Cit supplementation upregulated the mitochondrial transcription factor A and during HS, L-Cit increased ATP5β expression similar to TNZ housed broilers. Therefore, this study demonstrates that dietary L-Cit can lower the body temperature, decrease lipid peroxidation and promote the immune status of broilers under thermoneutrality. Also, L-Cit would act to promote muscle ATP generation during heat stress in broilers.

Dietary L-citrulline influences body temperature and inflammatory responses during nitric oxide synthase inhibition and endotoxin challenge in chickens

Recent studies have revealed the role of L-citrulline (L-CIT) in thermoregulation, but very little is known about the mechanisms involved. In this study, nitric oxide synthase inhibition and endotoxin-induced fever were used to investigate the effects of L-CIT on body temperature and inflammatory responses. In experiment 1, NW-nitro-L-arginine methyl ester (L-NAME, 150 mg/kg BW), was i. p. injected into chicks fed with basal (CON) or L-CIT diets for 14 days. In experiment 2, Lipopolysaccharide (LPS, 2 mg/kg BW) was i. p. injected following 21d feeding with CON or L-CIT diets. In experiment 3, chickens were injected with either L-NAME, LPS, or L-NAME + LPS following 26 days feeding with CON or L-CIT diets. The rectal (RT), ear (ET), and core body temperature (CBT) of chickens were examined. Results showed that L-NAME effectively decreased the RT, ET, CBT, and plasma NO concentration. In contrast, LPS increased NO levels and initiated hyperthermia by increasing RT, ET, CBT, and PGE2 levels. L-CIT diet reduced the mean CBT in experiment 1 and diminished the NO level, PGE2 level, and mean RT in experiment 3. Co-administration of L-CIT + LPS upregulated IL-6 expression, whereas, LPS injection alone induced IL-10, IL-1β, and TLR4 gene expressions. Therefore, this study reveals that L-CIT-induced hypothermia was related to NO inhibition and a decrease in PGE2 concentration. Conversely, LPS induced hyperthermia was associated with an increase in both NO and PGE2 concentrations.

Comparison of Combined Forced-Air Warming and Circulating-Water-Mattress and Forced-Air Warming Alone in Patients Undergoing Open Abdominal Surgery in Lithotomy Position: a Randomized Controlled Trial

The objective of this study was to evaluate the efficacy of warming devices in patients undergoing open abdominal surgery in lithotomy position. This randomized, controlled trial was designed to compare body temperatures of patients undergoing open abdominal surgery in lithotomy position between February and May 2019. After prewarming for 30 min with forced-air using a full-body blanket, patients were randomized to receive intraoperative warming either with forced-air using a blanket covering the upper torso and upper extremities in combination with circulating-water-mattress warming the back (Group I) or with only forced-air using blanket covering the upper torso and upper extremities (Group II). Primary outcome measure was the intraoperative change in core-body temperature using oesophageal temperature probe. A total of 28 patients were randomized. The mean core-body temperatures (Group I: 36.1 SD0.41 vs Group II: 35.9 SD0.53 °C; p=0.139) and intraoperative changes (Group I: 0.41% vs Group II: − 0.001%; p=0.306) were similar. The core-body temperature at the end of the operation correlated with the operating room temperature in Group II (r=0.862, p<0.001), but not in Group I (r=0.323, p=0.259). The combination of forced-air warming and circulating-water-mattress for open abdominal surgery in the lithotomy position may be more beneficial than forced-air warming alone, due to maintenance of the intraoperative mean core-body temperature ≥36°C, despite variations in operating room temperature. Trial Registry Number: ClinicalTrials.gov Identifier: NCT03824262 (Date of registry: 29 January 2019)

Autonomic dysregulation as an early pathologic feature of Huntington Disease.

Autonomic nervous system (ANS) dysfunction has been described in adults with motor-manifest Huntington's Disease (HD) or those who are near their predicted motor onset. It is unclear if ANS dysfunction is present years prior to the onset of motor symptoms of HD. To bridge this gap in knowledge, we compared crude markers of ANS function between children with the gene-expansion that causes HD (GE group) who were decades from their predicted motor onset and gene-non-expanded children (GNE group). We included participants from the Kids-HD study who were <18years old. Linear mixed effects regression models were constructed that controlled for sex, age, and BMI, and included a random effect per participant and per family. We compared resting heart rate (rHR), core body temperature (CBT), systolic blood pressure (SBP), and diastolic blood pressure (DBP) between the GE (n=84) and GNE (n=238) groups. We then grouped participants from the GE group based on their predicted years to onset (YTO) and compared their vital signs to the GNE group. The GE group had higher rHR (∆=3.83, p=0.0064), SBP (∆=2.38, p=0.032), and CBT (∆=0.16, t=2.92, p=0.007). The mean rHR and CBT became significantly elevated compared to the GNE group in participants who had 15-25 YTO and those who had <15 YTO. The mean SBP of participants who had 25-35 YTO was significantly elevated compared to the GNE group. ANS dysfunction in HD seems to occur approximately 20years prior to the predicted onset of motor symptoms of HD.

Aortic arch surgery at 32°C: mild hypothermia and unilateral antegrade cerebral perfusion.

With development of antegrade cerebral perfusion, the necessity of deep hypothermic circulatory arrest (CA) in aortic arch surgery has been called into question. To minimize the adverse effects of hypothermia, surgeons now perform these procedures closer to normothermia. This study examined postoperative outcomes of hemiarch replacement patients using unilateral selective antegrade cerebral perfusion and mild hypothermic CA. Single-centre retrospective review of 66 patients undergoing hemiarch replacement with mild hypothermic CA (32°C) and unilateral selective antegrade cerebral perfusion between 2011 and 2018. Antegrade cerebral perfusion was delivered using right axillary artery cannulation. Postoperative data included death, neurological dysfunction, acute kidney injury and renal failure requiring new dialysis. Additional intraoperative metabolic data and blood transfusions were obtained. Eighty-six percent of patients underwent elective surgery. Mean age was 67 ± 3 years. Lowest mean core body temperature was 32 ± 2°C. Average CA was 17 ± 5 min. No intraoperative or 30-day mortality occurred. Survival was 97% at 1 year, 91% at 3 years and 88% at 5 years. Permanent and temporary neurological dysfunction occurred in 1 (2%) and 2 (3%) patients, respectively. Only 3 (5%) patients suffered postoperative stage 3 acute kidney injury requiring new dialysis. Intraoperative transfusions occurred in 44% of patients and no major metabolic derangements were observed. In patients undergoing hemiarch surgery, mild hypothermia (32°C) with unilateral selective antegrade cerebral perfusion via right axillary cannulation is associated with low mortality and morbidity, offering adequate neurological and renal protection. These findings require validation in larger, prospective clinical trials.

Effect of an Innovative Mattress and Cryotherapy on Sleep after an Elite Rugby Match.

This study aimed to explore the relationship between elite rugby union match and postmatch sleep architecture and to investigate the effects of a high-heat capacity mattress (MAT) and a whole-body cryotherapy (WBC) session on postmatch sleep architecture. Nineteen elite male U23 rugby union players performed in three official matches, followed by three experimental conditions, in a randomized order: MAT, WBC, and no intervention (CONT). Match load was evaluated using GPS trackers and video analyses. Sleep architecture was assessed by polysomnography (PSG). Core body temperature (CBT) and mattress surface temperature were monitored during sleep. Linear mixed-effects models were conducted to assess the effects of each experimental condition on sleep, with match load variables as covariates. A lower wake after sleep onset (β = -10.5 min, P < 0.01) and higher rapid eye movement sleep proportion (β = +2.8%, P < 0.05) were reported for MAT compared with CONT. Moreover, lower mean CBT (β = -0.135°C, P < 0.001) and mean mattress surface temperature (β = -2.736°C, P < 0.001) during sleep were observed for MAT compared CONT. WBC did not affect nocturnal CBT nor interfere with sleep architecture. For every 100-m increase in high-speed running distance, a higher slow wave sleep (β = +1.1%, P = 0.05) and lower light sleep proportion (β = -1.2%, P < 0.05) proportion were observed. Conversely, for every 10 supplementary collisions, lower slow wave sleep (β = -1.9, P = 0.09) and higher light sleep (β = +2.9%, P < 0.001) proportion were observed. MAT use had a positive effect on sleep architecture after an elite rugby union match, potentially through a more efficient nocturnal heat transfer.

An Occupational Heat Stress and Hydration Assessment of Agricultural Workers in North Mexico.

Expanding agribusiness in Northern Mexico has increased demand for workers from Southern Mexico, with hundreds of thousands migrating for work annually. Extreme temperatures, physical labor, and low fluid consumption place workers at risk for heat strain and dehydration, commonly underreported hazards in the agricultural industry. The objectives of this pilot study were to assess heat exposure and hydration status of a population of migratory agricultural workers in Northern Mexico throughout the grape harvest season. In addition to demographic information, environmental conditions, hydration status, and core body temperatures were collected. The majority listed Chiapas as their home state, nearly half spoke an Indigenous language, and none had completed high school. The wet-bulb globe temperature was significantly higher during the harvest and post-harvest seasons compared to the pre-harvest season. Across the different seasons, the majority were dehydrated post-shift, and mean core body temperature of workers was not significantly different. This project highlights the need for targeted interventions to improve hydration and prevent heat stress in this region. As the number of warm days is expected to rise each year worldwide, it will be increasingly important to engage in practices to protect vulnerable populations, such as migratory agriculture workers.

Forced air-warming blanket versus pethidine for the prevention of shivering during and after caesarean section

Background Spinal anaesthesia significantly impairs thermoregulation by inhibiting vasomotor and shivering responses and by redistributing heat from the core of body to peripheral tissues. Core hypothermia may be associated with a number of adverse outcomes in pregnant women, including shivering, wound infection, coagulopathy, increased blood loss and transfusion requirements. Several pharmacological and mechanical methods have been used in an attempt to maintain normothermia and prevent intra-anaesthetic and postanaesthetic shivering. Therefore, the aim of the present study was to compare the efficacy of prophylactic use of forced air-warming blanket with pethidine for the prevention of shivering during and after spinal anaesthesia in elective caesarean section. Patients and methods The present study included 96 pregnant women with ASA I and II, admitted to Al Shatby Maternity Hospital. Patients were randomly assigned into three equal groups of 32 patients each. Group I patients were covered with forced air-warming blanket over the upper limbs and chest, group II patients received a single bolus of 0.5 mg/kg pethidine intravenously and group III patients did not receive anything, and they were regarded as control. Results Heart rate and mean arterial blood pressure decreased significantly in all the three studied groups after spinal anaesthesia. The decrease in the mean arterial blood pressure required ephedrine boluses, which ranged between 0 and 4 boluses, with no significance between the three studied groups. The core body temperature decreased significantly 15 min after spinal anaesthesia and thereafter in all patients of the three studied groups. However, the decrease in core temperature was significantly more in groups II and III. The shivering score increased significantly 10 min after spinal anaesthesia and thereafter intraoperatively. The shivering scores were significantly lower in groups I and II when compared with group III. There was a negative correlation between core body temperature and shivering scores in all the three studied groups. The mean core body temperature for shivering patients was significantly less in group II patients compared with groups I and III patients. The three groups were matched as regard to APGAR score at 1 and 5 min. No significant changes were observed as regard to hypotension, nausea, vomiting and feeling cold extremities. Conclusion Forced air-warming blanket decreased the shivering incidence by preserving core body temperature, whereas pethidine can prevent and treat shivering.

Body temperature patterns vary with day, season, and body condition of moose (Alces alces)

Abstract Variation in core body temperature of mammals is a result of endogenous regulation of heat from metabolism and the environment, which is affected by body size and life history. We studied moose (Alces alces) in Alaska to examine the effects of endogenous and exogenous factors on core body temperature at seasonal and daily time scales. We used a modified vaginal implant transmitter to record core body temperature in adult female moose at 5-min intervals for up to 1 year. Core body temperature in moose showed a seasonal fluctuation, with a greater daily mean core body temperature during the summer (38.2°C, 95% CI = 38.1–38.3°C) than during the winter (37.7°C, 95% CI = 37.6–37.8°C). Daily change in core body temperature was greater in summer (0.92°C, 95% CI = 0.87–0.97°C) than in winter (0.58°C, 95% CI = 0.53–0.63°C). During winter, core body temperature was lower and more variable as body fat decreased among female moose. Ambient temperature and vapor pressure accounted for a large amount of the residual variation (0.06–0.09°C) in core body temperature after accounting for variation attributed to season and individual. Ambient temperature and solar radiation had the greatest effect on the residual variation (0.17–0.20°C) of daily change in core body temperature. Our study suggests that body temperature of adult female moose is influenced by body reserves within seasons and by environmental conditions within days. When studying northern cervids, the influence of season and body condition on daily patterns of body temperature should be considered when evaluating thermal stress.

Magnitude and associated factors of Perioperative hypothermia in patients who underwent Elective surgery at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia.

Background : Body temperature is a vital sign and 37°C is the mean core body temperature of a healthy human. Core body temperature is normally tightly regulated and maintained within narrow range. Perioperative hypothermia is one of the major problems during surgery and anesthesia that can affect operated patients. Methods: Institutional based cross-sectional study was conducted. Patient interview, chart review and temperature measurement were employed for data collection. Temperature was measured using tympanic membrane thermometer. SPSS version 20 software was used for analysis. binary logistic regression was used to look at associations anda p-value of &lt;0.05 was considered statistically significant.&#x0D; Result :The overall magnitude of preoperative, intra and post-operative hypothermia in this study was 16.2%, 53.2% and 31.3%, respectively. Age (AOR=7.15, 95% CI, 1.16, 43.99), coexisting illness (AOR, 3.32, 95% CI, 1.06; 10.36), preoperative hypothermia (AOR; 57; 95% CI; 7.1, 455.4), operation room temperature (AOR=1.91; 95 % CI, 1.04; 3.5) and crystalloid fluids administered (AOR; 2.3; 95% CI, 1.07, 4.9) were found to be factors associated with intraoperative hypothermia.&#x0D; Conclusion and recommendation: The magnitude of perioperative hypothermia remains high. Measures should focus on improving room temperature and warming up fluids. Susceptible patients like the aged and those with coexisting disease should be given extra attention.&#x0D;

Animal factors associated with core body temperature of nonlactating dairy cows during summer.

The primary objectives of the current study were to investigate animal factors associated with core body temperature (CBT) and to determine the time of the day in which CBT assessment best describes the magnitude of hyperthermia throughout the day of heat-stressed dry cows. The secondary objective was to develop a predictive model for CBT of dry cows. Nonlactating Holstein cows (n = 105) with 250 to 260 d of gestation from 2 commercial dairies were enrolled in the study during summer. During 4 consecutive days, CBT from all cows was recorded in 5-min intervals and average CBT was calculated for each cow. In addition, mean, maximum, minimum, and standard deviation of daily CBT were calculated and using these measures cows were categorized as having high temperature (HT) or low temperature (LT) based on the median values. Cows carrying twins had greater (P < 0.01) CBT than cows bearing singletons (39.07 ± 0.07 vs. 38.84 ± 0.03 °C). Average CBT decreased (P < 0.01) 0.015 ± 0.004 °C for each 1-d increase in gestation length. Cows in Dairy A tended (P = 0.09) to have lower CBT than cows in Dairy B (38.91 ± 0.04 vs. 39.00 ± 0.06 °C). Season of birth, lactation number, body condition score category, previous projected 305-d mature equivalent milk yield, days in milk at dry-off, days after dry-off at enrollment, days of gestation at enrollment, and calf sex were not associated (P > 0.12) with CBT. Principal component analyses showed that 71% of the variance of CBT was explained by the first principal component alone, which was correlated with mean CBT (r = 0.99). Among all time points assessed, CBT recorded at 2215 h had the highest correlation with the first principal component (r = 0.93). The best agreement for classifying cows as HT or LT was between mean daily CBT and assessment at 2215 h (k = 0.73). The model that resulted in best predictivity (0.56) of average CBT included the following variables: dairy, gestation length, and twinning. In conclusion, findings from the present study suggest that CBT assessed between 250 and 260 d of gestation is negatively associated with gestation length and cows bearing twins have greater CBT than singletons. Our results indicate that the best time of the day to evaluate severity of heat stress in dry cows is 2215 h. Predictive models for CBT of dry cows should include dairy, twinning, and gestation length.

Core Body Temperature but Not Intraabdominal Pressure Predicts Postoperative Complications Following Closed-System Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Administration.

Hyperthermic intraperitoneal chemotherapy (HIPEC) following cytoreductive surgery (CRS), performed using closed-abdomen technique (CAT), may affect intraabdominal pressure (IAP). High IAP may increase postoperative complications due to decreased venous return and hypoperfusion to vital organs. Elevated core body temperature (CBT) may cause multiorgan dysfunction. Low IAP or CBT could result in suboptimal HIPEC and potentially translate into early disease recurrence. The aim of the present study is to identify possible correlations between IAP or CBT and postoperative complications. Continuous intraabdominal pressure measurement was performed by intraabdominal catheter. Inflow temperature was set at 44°C, and mean perfusate temperature was 42°C. CBT was measured continuously in the distal esophagus. We compared the rate of postoperative complications between the low IAP group (2-10mmHg, n=28), target IAP group (10-20mmHg, n=71), and high IAP group (20-34mmHg, n=16) as well as with CBT as a continuous variable. 115 patients were included in the study. There was no difference between IAP groups in terms of age, gender, primary diagnosis, operative peritoneal cancer index, CBT, or operative time. There was no correlation between IAP and postoperative complications or with prolonged hospital stay. On multivariate analysis, elevated mean CBT was a positive predictor of postoperative complications (p=0.035). IAP level during closed-abdomen technique HIPEC is not associated with postoperative complications. However, elevated CBT may increase postoperative complications.

Implementation of Neurocritical Care Is Associated With Improved Outcomes in Traumatic Brain Injury.

We conducted a single-center quasi-experimental uncontrolled pre- and post-NCC study in severe traumatic brain injury patients (Glasgow Coma Scale ≤8). The NCC program includes consultation with a neurointensivist and neurosurgeon and multimodal neuromonitoring. Demographic, injury severity metrics, neurophysiologic data, and therapeutic interventions were collected. Glasgow Outcome Scale (GOS) at 6 months was the primary outcome. Multivariable ordinal logistic regression was used to model the association between NCC implementation and GOS at 6 months. A total of 113 patients were identified: 76 pre-NCC and 37 post-NCC. Mean age was 39 years (standard deviation [SD], 2) and 87 of 113 (77%) patients were male. Median admission motor score was 3 (interquartile ratio, 1-4). Daily mean arterial pressure was higher (95 mmHg [SD, 10]) versus (88 mmHg [SD, 10], p<0.001) and daily mean core body temperature was lower (36.6°C [SD, 0.90]) versus (37.2°C [SD, 1.0], p=0.001) post-NCC compared with pre-NCC, respectively. Multivariable regression modelling revealed the NCC program was associated with a 2.5 increased odds (odds ratios, 2.5; 95% confidence interval, 1.1-5.3; p=0.022) of improved 6-month GOS. Implementation of a NCC program is associated with improved 6 month GOS in severe TBI patients.

Repeated anaesthesia with isoflurane and medetomidine-midazolam-fentanyl in guinea pigs and its influence on physiological parameters.

Repeated anaesthesia may be required in experimental protocols and in daily veterinary practice, but anaesthesia is known to alter physiological parameters in GPs (Cavia porcellus, GPs). This study investigated the effects of repeated anaesthesia with either medetomidine-midazolam-fentanyl (MMF) or isoflurane (Iso) on physiological parameters in the GP. Twelve GPs were repeatedly administered with MMF or Iso in two anaesthesia sets. One set consisted of six 40-min anaesthesias, performed over 3 weeks (2 per week); the anaesthetic used first was randomized. Prior to Iso anaesthesia, atropine was injected. MMF anaesthesia was antagonized with AFN (atipamezole-flumazenil-naloxone). Abdominally implanted radio-telemetry devices recorded the mean arterial blood pressure (MAP), heart rate (HR) and core body temperature continuously. Additionally, respiratory rate, blood glucose and body weight were assessed. An operable state could be achieved and maintained for 40 min in all GPs. During the surgical tolerance with MMF, the GPs showed a large MAP range between the individuals. In the MMF wake- up phase, the time was shortened until the righting reflex (RR) returned and that occurred at lower MAP and HR values. Repeated Iso anaesthesia led to an increasing HR during induction (anaesthesias 2–6), non-surgical tolerance (anaesthesias 3–6) and surgical tolerance (anaesthesias 4, 6). Both anaesthetics may be used repeatedly, as repeating the anaesthesias resulted in only slightly different physiological parameters, compared to those seen with single anaesthesias. The regular atropine premedication induced HR increases and repeated MMF anaesthesia resulted in a metabolism increase which led to the faster return of RR. Nevertheless, Iso’s anaesthesia effects of strong respiratory depression and severe hypotension remained. Based on this increased anaesthesia risk with Iso, MMF anaesthesia is preferable for repeated use in GPs.

Effect of shortened sleep on energy expenditure, core body temperature, and appetite: a human randomised crossover trial

The effects of sleep restriction on energy metabolism and appetite remain controversial. We examined the effects of shortened sleep duration on energy metabolism, core body temperature (CBT), and appetite profiles. Nine healthy men were evaluated in a randomised crossover study under two conditions: a 3.5-h sleep duration and a 7-h sleep duration for three consecutive nights followed by one 7-h recovery sleep night. The subjects’ energy expenditure (EE), substrate utilisation, and CBT were continually measured for 48 h using a whole-room calorimeter. The subjects completed an appetite questionnaire every hour while in the calorimeter. Sleep restriction did not affect total EE or substrate utilisation. The 48-h mean CBT decreased significantly during the 3.5-h sleep condition compared with the 7-h sleep condition (7-h sleep, 36.75 ± 0.11 °C; 3.5-h sleep, 36.68 ± 0.14 °C; p = 0.016). After three consecutive nights of sleep restriction, fasting peptide YY levels and fullness were significantly decreased (p = 0.011), whereas hunger and prospective food consumption were significantly increased, compared to those under the 7-h sleep condition. Shortened sleep increased appetite by decreasing gastric hormone levels, but did not affect EE, suggesting that greater caloric intake during a shortened sleep cycle increases the risk of weight gain.

Extracorporeal Life Support for Refractory Cardiac Arrest from Accidental Hypothermia: A 10-Year Experience in Edinburgh

BackgroundCardiac arrest caused by accidental hypothermia is a rare phenomenon with a significant mortality rate if untreated. The consensus is that these patients should be rewarmed with extracorporeal life support (ECLS) with the potential for excellent survival and neurologic outcomes. However, given the lack of robust data and clinical trials, the optimal management of such patients remains elusive. ObjectiveIn this single-center study, we looked at the outcomes of all adult patients undergoing salvage ECLS for cardiac arrest caused by accidental hypothermia over a 10-year period from June 2006 to June 2016. MethodsThese data were obtained from the Royal Infirmary of Edinburgh cardiothoracic surgery database. The patients' hard copy case notes, TrakCare (InterSystems Corp, Cambridge, MA), picture archiving and communications system (PACS), and WardWatcher databases were used to cross-check the accuracy of the acquired data. ResultsEleven patients met the inclusion criteria. The etiology of hypothermia was exposure to cold air (64%) and cold water immersion (36%). Two (18%) were treated with extracorporeal membrane oxygenation and the rest with cardiopulmonary bypass. The mean age was 51 years (range 32–73), and the mean core body temperature on admission was 20.6°C (range <18–24°C). The overall survival rate to hospital discharge was 72%, with 75% of survivors having no chronic neurologic impairment. ConclusionOur case series shows the remarkable salvageability of patients suffering prolonged cardiac arrest caused by accidental hypothermia, particularly in the absence of asphyxia, trauma, or severe hyperkalemia. ECLS is a safe and effective rewarming treatment and should be used to aggressively manage this patient group.

Intraoperative temperature regulation in children using a liquid-warming garment.

Children undergoing operative intervention while induced under general anesthesia are at risk for experiencing a significant decrease in core body temperature that can lead to adverse systemic effects. Given that the head contributes an estimated 18% of a child's body surface area, we theorized that a liquid-warming garment applied to the head could control a pediatric patient's core body temperature during surgical procedures. Patients undergoing elective, non-cranial, general surgical procedures were enrolled in the study. A head garment with an embedded network of tubing was placed on the patient. The garment connected to a computer-controlled water bath that managed the temperature of the water in the tubing through a feedback mechanism. Ten patients with ages ranging from 1day to 3years (mean age 10.5months) were enrolled in this study. The average procedure length was 82.5min. The mean core body temperature throughout the procedure for all-comers was 36.5±0.9°C with an overall mean difference in maximum and minimum temperatures of 1.32±1.1°C. A liquid-warming garment applied to the head of pediatric surgical patients is an innovative and relatively low-cost means to regulate and to maintain the ideal core body temperature of patients undergoing surgical procedures.

Active perioperative patient warming using a self-warming blanket (BARRIER EasyWarm) is superior to passive thermal insulation: a multinational, multicenter, randomized trial

Study ObjectiveIncidence of inadvertent perioperative hypothermia is still high; therefore, present guidelines advocate “prewarming” for its prevention. Prewarming means preoperative patient skin warming, which minimizes redistribution hypothermia caused by induction of anesthesia. In this study, we compared the new self-warming BARRIER EasyWarm blanket with passive thermal insulation regarding mean perioperative patient core body temperature. DesignMultinational, multicenter randomized prospective open-label controlled trial. SettingSurgical ward, operation room, postanesthesia care unit at 4 European hospitals. PatientsA total of 246 adult patients, American Society of Anesthesiologists class I to III undergoing elective orthopedic; gynecologic; or ear, nose, and throat surgery scheduled for 30 to 120 minutes under general anesthesia. InterventionsPatients received warmed hospital cotton blankets (passive thermal insulation, control group) or BARRIER EasyWarm blanket at least 30 minutes before induction of general anesthesia and throughout the perioperative period (intervention group). MeasurementsThe primary efficacy outcome was the perioperative mean core body temperature measured by a tympanic infrared thermometer. Secondary outcomes were hypothermia incidence, change in core body temperature, length of stay in postanesthesia care unit, thermal comfort, patient satisfaction, ease of use, and adverse events related to the BARRIER EasyWarm blanket. Main ResultsThe BARRIER EasyWarm blanket significantly improved perioperative core body temperature compared with standard hospital blankets (36.5°C, SD 0.4°C, vs 36.3, SD 0.3°C; P<.001). Intraoperatively, in the intervention group, hypothermia incidence was 38% compared with 60% in the control group (P=.001). Postoperatively, the figures were 24% vs 49%, respectively (P=.001). Patients in the intervention group had significantly higher thermal comfort scores, preoperatively and postoperatively. No serious adverse effects were observed in either group. ConclusionsPerioperative use of the new self-warming blanket improves mean perioperative core body temperature, reduces the incidence of inadvertent perioperative hypothermia, and improves patients' thermal comfort during elective adult surgery.