Comparison of Two Different Uses of Underbody Forced-air Warming Blankets for the Prevention of Hypothermia in Patients Undergoing Arthroscopic Shoulder Surgery: a Prospective Randomized Study

Background: Forced-air warming (FAW) is an effective method of preventing inadvertent perioperative hypothermia (IPH). However, its warming effects can be influenced by the style and position of the FAW blanket. This study aimed to compare the effects of underbody FAW blankets being placed under or over patients in preventing IPH.Methods: Patients (n=100) undergoing elective arthroscopic shoulder surgery in the lateral decubitus position were randomized into either under body (UB) group or the over body (OB) group (50 per group). The core body temperature (CBT) of the patients was recorded from baseline to the end of anesthesia. The incidences of postoperative hypothermia and shivering were also collected.Results: A steady decline in the CBT was observed in both groups up to 60 minutes after the start of FAW. After 60 minutes of warming, the OB group showed a gradual increase in the CBT. However, the CBT still decreased in UB group until 75 minutes, with a low of 35.7℃ ± 0.4℃. Then the CBT increased mildly and reached 35.8℃ ± 0.4℃ at 90 minutes. After 45 minutes of warming, the CBT was significantly different (P < 0.05). The incidence of postoperative hypothermia in the UB group was significantly higher than that in the OB group (P = 0.023).Conclusions: The CBT was significantly better when the underbody FAW blanket was placed over patients compared with under the patients. However, there was not a clinically significant difference in CBT. The incidence of postoperative hypothermia was much lower in the OB group. Therefore, placing underbody FAW blankets over patients is recommended for the prevention of IPH in patients undergoing arthroscopic shoulder surgery.Trial registration: This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 13/1/2021 with the registration number ChiCTR2100042071. It was conducted from 14/1/2021 to 30/10/2021 as a single, blinded trial in Sichuan Provincial Orthopedic Hospital.

Effect of Music on Stress Parameters in Dogs during a Mock Veterinary Visit

Veterinary visits can be stressful for dogs, but how their wellbeing changes during a visit is not well understood. Music therapy has been successfully used in clinical practice to alleviate stress and anxiety in people. The present study aimed to understand how canine stress changes during a veterinary visit, establish the effect of music, and highlight measures which may be of practical use. In a randomized crossover design, dogs were exposed to no music and a bespoke piece of classical music at a tempo designed to match their resting heart rate during a mock veterinary visit. Dogs were scored as more “afraid” during the physical examination compared to when they were in the hospital kennel (p < 0.001). Salivary cortisol, IgA, and infrared temperature all increased significantly (p < 0.05) from baseline to post-kennel and post-examination, with no effect of music treatment. Core body temperature (p = 0.010) and the odds of ‘relaxed’ lips (p = 0.020) were lower when dogs were exposed to music compared to control visits. Overall, dogs experienced changes in physiology and behavior, indicative of increased stress, over the course of the visit. Additional research is required to further understand the effect that bespoke music may have in alleviating canine stress during veterinary visits.

Non-Invasive Assessment of Mild Stress-Induced Hyperthermia by Infrared Thermography in Laboratory Mice

Stress-induced hyperthermia (SIH) is a physiological response to acute stressors in mammals, shown as an increase in core body temperature, with redirection of blood flow from the periphery to vital organs. Typical temperature assessment methods for rodents are invasive and can themselves elicit SIH, affecting the readout. Infrared thermography (IRT) is a promising non-invasive alternative, if shown to accurately identify and quantify SIH. We used in-house developed software ThermoLabAnimal 2.0 to automatically detect and segment different body regions, to assess mean body (Tbody) and mean tail (Ttail) surface temperatures by IRT, along with temperature (Tsc) assessed by reading of subcutaneously implanted PIT-tags, during handling-induced stress of pair-housed C57BL/6J and BALB/cByJ mice of both sexes (N = 68). SIH was assessed during 10 days of daily handling (DH) performed twice per day, weekly voluntary interaction tests (VIT) and an elevated plus maze (EPM) at the end. To assess the discrimination value of IRT, we compared SIH between tail-picked and tunnel-handled animals, and between mice receiving an anxiolytic drug or vehicle prior to the EPM. During a 30 to 60 second stress exposure, Tsc and Tbody increased significantly (p < 0.001), while Ttail (p < 0.01) decreased. We did not find handling-related differences. Within each cage, mice tested last consistently showed significantly higher (p < 0.001) Tsc and Tbody and lower (p < 0.001) Ttail than mice tested first, possibly due to higher anticipatory stress in the latter. Diazepam-treated mice showed lower Tbody and Tsc, consistent with reduced anxiety. In conclusion, our results suggest that IRT can identify and quantify stress in mice, either as a stand-alone parameter or complementary to other methods.

Notes from the Field: The Construction of a Logistical Model for Sports-Related Injury Risk Assessment. A Cross-Sectional Pilot Study

Handball is a high-intensity contact sports activity characterized by repetitive movements, leading to sport-specific muscle patterns. However, at some stage, this pattern may turn into imbalance, predisposing athletes for injuries. The complexity of muscular interactions often makes it difficult to see a whole picture of an athlete’s postural disorders and assess them within the framework of his stereotyped movements. We attempted to find an association between the muscle pattern and the number of injuries in a limited group of handball players by constructing a static logistical model. The constructed decision table of the static logistical model included seven conditional attributes of the muscle imbalance as preconditions for injury development and one decision attribute representing the number of experienced injuries of 25 university handball players. The findings displayed a sport-specific pattern of muscle alignment in athletes without or only one injury. However, all players with repetitive injuries had unilateral m. gluteus maximus weakness. In the latter case, impaired core body musculature can lead to increased share forces and stress for the gluteus maximus muscle leading to weakness of this crucial dynamic stabilizer. The logistical model allowed defining muscle imbalance associated with sports-related injuries in a limited group of athletes.

Influence of Cold-TRP Receptors on Cold-Influenced Behaviour

The transient receptor potential (TRP) channels, TRPA1 and TRPM8, are thermo-receptors that detect cold and cool temperatures and play pivotal roles in mediating the cold-induced vascular response. In this study, we investigated the role of TRPA1 and TRPM8 in the thermoregulatory behavioural responses to environmental cold exposure by measuring core body temperature and locomotor activity using a telemetry device that was surgically implanted in mice. The core body temperature of mice that were cooled at 4 °C over 3 h was increased and this was accompanied by an increase in UCP-1 and TRPM8 level as detected by Western blot. We then established an effective route, by which the TRP antagonists could be administered orally with palatable food. This avoids the physical restraint of mice, which is crucial as that could influence the behavioural results. Using selective pharmacological antagonists A967079 and AMTB for TRPA1 and TRPM8 receptors, respectively, we show that TRPM8, but not TRPA1, plays a direct role in thermoregulation response to whole body cold exposure in the mouse. Additionally, we provide evidence of increased TRPM8 levels after cold exposure which could be a protective response to increase core body temperature to counter cold.

Heat Exposure and Physiological Changes among Cooks

Cooks who are exposed to heat produced from stoves when working in the kitchen are at risk of thermal stress and heat-related illness. Physiological changes such as increased heart rate, sweat production and blood pressure may also affect them. This study aimed to determine the area heat exposure levels and physiological changes including core body temperature, blood pressure and heart rate during pre-, mid- and post-shift among cooks and its association, and to compare the mean difference of physiological changes between the shifts. This cross-sectional study utilised the purposive sampling method and recruited 30 cooks from food stalls and cafeterias in Kelantan. Area heat measurements were collected from 14 sites (7 inside and 7 outside the USM Health Campus). Wet-bulb Globe Temperature (WBGT) monitor was mounted on a tripod at 1.1 m height near the source of heat for 8 hours. The core body temperature, blood pressure, and heart rate were taken three times per day during pre-, mid- and post-shift for physiological changes measurement. Respondents’ personal information, health history, work description, and symptoms of heat-related illness were collected using a questionnaire. The overall WBGT area levels at each sampling site were homogeneously distributed. There was significant increase in core body temperature and heart rate from pre-shift to post-shift. However, there was no significant correlation (p>0.05) between heat exposure (WBGT index) established with the physiological changes. This may suggest that the increase in core body temperature and heart rate might be attributed to other factors and needed further investigation.