Changes In Tympanic Membrane Temperature Research Articles

Does the Laminar Airflow System Affect the Development of Perioperative Hypothermia? A Randomized Clinical Trial.

We aimed to compare tympanic membrane temperature changes and the incidence of inadvertent perioperative hypothermia (IPH) in patients undergoing laparoscopic cholecystectomy under general anesthesia in laminar airflow systems (LAS-OR) and conventional turbulent airflow systems (CAS-OR). Different heating, ventilation, and air-conditioning (HVAC) systems are used in the operating room (OR), such as LAS and CAS. Laminar airflow is directed directly to the patient in LAS-OR. Does laminar airflow in ORs cause faster heat loss by convection? This is a prospective, randomized study. We divided 200 patients with simple randomization (1:1), as group LAS and group CAS, and took the patients into the LAS-OR or CAS-OR for the operation. Clinical trial number: IRCT20180324039145N3. The tympanic membrane temperatures of patients were measured (°C) before anesthesia induction (T0) and then every 15 min during surgery (Tn). Changes (Δn) between T0 and Tn were measured. In the first 30 min, there was a temperature decrease of approximately 0.8 °C (1.44 °F) in both groups. Temperature decreases at 45 min were higher in group LAS than in group CAS but not statistically significant, Δ45, respectively, 0.89 (95% confidence interval [CI] [0.77, 1.02]) versus 0.77 (95% CI [0.69, 0.84]; p = .09). IPH occurred in a total of 60.9% (112 of 184) of patients in the entire surgical evaluation period in group LAS and group CAS (58.9% vs. 62.8%, p = . 59). IPH is seen frequently in both HVAC systems. Clinically, the advantage of HVAC systems relative to each other has not been demonstrated during laparoscopic cholecystectomy.

The Impact of a 20-Minute Animal-Assisted Activity Session on the Physiological and Emotional States in Patients With Fibromyalgia

ObjectiveTo study the direct physiological and emotional impact of an animal-assisted activity (AAA) session (a form of complementary and integrative medicine) in patients with fibromyalgia (FM). Patients and MethodsThe study population consisted of 221 participants with FM who were attending Mayo Clinic’s Fibromyalgia Treatment Program between August 5, 2017, and September 1, 2018. This was a randomized controlled trial. Participants were randomly assigned to either the treatment group (a 20-minute session with a certified therapy dog and handler) or the control group (a 20-minute session with a handler only). To gain a better understanding of the direct physiological and emotional effects of AAA in patients with FM, we used multiple noninvasive physiologic-emotional biomarkers, including salivary cortisol and oxytocin concentrations, tympanic membrane temperatures, and various cardiac parameters, in addition to standardized pain and mood-based questionnaires. ResultsResults show a decrease in heart rate, an increase in heart rate variability, an increase in well-being survey scores, an increase in salivary oxytocin, and subsequent tympanic membrane temperature changes, suggesting that participants in the treatment group were in a more positive emotional-physiologic state as a result of the AAA session compared with the control group. ConclusionOur results suggest that a 20-minute therapy dog visit in an outpatient setting can significantly and positively impact the physical and mental health of patients with FM.

Rightward Tympanic Membrane Temperature Bias During Acute Restraint-Isolation Stress in Marmoset Monkeys.

Restraint is widely used to experimentally assess stress-induced effects. Surprisingly, little is known on how marmosets – an increasingly used small primate – process and respond to restraint stress. Here, we assessed blood cortisol concentration and tympanic membrane temperatures (TMT) in adult marmoset monkeys (Callithrix penicillata) during 0, 15, or 30 min of restraint and social isolation in a small cage. TMT reflects blood flow to the cerebral hemispheres, which in turn reflects neural activity. Baseline TMT were subtracted from post-test measures to establish shifts in blood flow possibly induced by ipsilateral brain activity. Cortisol was assayed immediately after the post-test assessment of the TMT. Marmosets restrained-isolated for 15 or 30 min had higher cortisol levels than the non-restrained-isolated group. Furthermore, significant changes in TMT were detected only in the right ear of the restrained-isolated groups, this effect being unrelated to overall body temperature or the time needed to capture/measure the TMT. Adult marmosets thus readily perceive a significant reduction in their range of movement as an event of sufficient negative intensity and/or duration to activate a pertinent neuroendocrine response. Also, an asymmetrical shift in their TMT reflects that such an aversive event may be rightwardly biased in this primate.

Natural predator and a human stimulus differently affect the behavior, cortisol and cerebral hemisphere activity of marmoset monkeys

The behavior, cortisol concentration and cerebral hemisphere activity of twelve marmoset monkeys were determined during standardized predatory stress-related events. Each subject was submitted to three 5-min trials, randomly held at 2-week intervals: a human intruder, a taxidermized oncilla cat and a no-stimulus control trial. Stimuli were positioned outside the home-cage and the ensuing reaction recorded. Baseline tympanic membrane temperature (TMT) was subtracted from the post-trial measure to determine changes in blood flow induced by ipsilateral brain activity. Cortisol was assayed immediately after the post-trial TMT assessments. Both genders reacted fearfully/anxiously towards the stimuli – each condition inducing a distinct pattern. Cortisol increased only when females were confronted with the wildcat, with higher levels of alarm calls predicting lower cortisol release. When either stimulus was present, changes in TMT were detected, albeit only in the right ear. The specific directional shift in temperature was gender- and stimulus-dependent, requiring further investigation. The control trial did not alter any of the parameters. Marmosets thus exhibit flexible multileveled coping strategies towards different aversive events, yet in general these seem to be asymmetrically processed by the right cerebral hemisphere.

Improvement of cerebral blood perfusion in certain cerebral regions after cranioplasty could be monitored via tympanic membrane temperature changes

ABSTRACTObjective: Delayed neurological deficit was often observed in patients underwent craniectomy, which could be improved by cranioplasty. Little is known about hemodynamic improvement before and after cranioplasty.Methods: Cerebral blood perfusion, tympanic membrane temperature (TMT), neuropsychological and cognitive function were assessed in eleven craniectomy patients before and after cranioplasty.Results: Before cranioplasty, the cerebral blood volume (CBV) on the decompressed side was significantly lower than that of the contralateral side. The cranioplasty led to instant improvement (7 days after cranioplasty) of cerebral perfusion at the cranioplasty side in the frontal lobe, parietal lobe, temporal lobe, mesencephalon, basal ganglia and thalamus, but not the occipital lobe and epencephalon. Interestingly, CBV of the thalamus and basal ganglia gradually decreased to pre-surgical status 6 months later while the frontal lobe, parietal lobe, temporal lobe, mesencephalon remained well perfused. Meanwhile, the TMT changes acquired positive correlation with the perfusion of temporal lobe and mesencephalon as well as the GCS and MMSE score.Conclusion: The cranioplasty remarkably improves neurological and cognitive function by ameliorating cerebral perfusion in certain regions. The TMT could be used as a non-invasive method to monitor the cerebral perfusion improvement after the cranioplasty.

Tympanic membrane temperature decreases during head up tilt: relation to frontal lobe oxygenation and middle cerebral artery mean blood flow velocity

Introduction: Changes in blood flow influence temperature of surrounding tissues. Since the internal carotid artery (ICA) and internal jugular vein (IJV) neighbor the tympanic membrane, changes in their blood flow most likely determine changes in tympanic membrane temperature (TMT). We sought to evaluate the relationship between changes during a head-up tilt (HUT) induced reduction in cerebral blood flow (CBF) and TMT.Methods: Ten male subjects (age 19–28 years) underwent 50° HUT until presyncope. A non-contact infrared sensor in the ear canal targeted the tympanic membrane. Changes in CBF were monitored by transcranial Doppler which determined the mean blood flow velocity in the middle cerebral artery (MCA Vmean) and by near infrared spectroscopy assessed frontal lobe oxygenation (ScO2), while skin blood flow (SkBF) was evaluated by laser Doppler flowmetry.Results: During HUT, TMT decreased by 0.6 °C (median; range 0.2 to 1.6 °C) related to a decrease in MCA Vmean (51.0 ± 6.7 to 34.3 ± 5.8 cm/sec (mean ± SD); r = 0.518, p = .002) and ScO2 (78.6 ± 5.4% to 69.0 ± 5.7%; r = 0.352, p = .043), but not to SkBF (120 ± 78 to 69 ± 37 PU; r = 0.245, p = .142).Conclusion: During an orthostatic challenge TMT decreases and the decrease is related to a reduction in CBF as indicated by MCA Vmean and ScO2, but not to SkBF. We consider TMT holds potential for non-invasive assessment of changes in cerebral perfusion.

Handedness and lateralised tympanic membrane temperature in relation to approach–avoidance behaviour in Garnett's bushbaby (Otolemur garnettii)

Studies of handedness suggest a relationship between hemispheric specialisation and emotional processing. Recently measures of lateralised tympanic membrane temperature (TMT) have identified similar relationships (i.e., the left hemisphere is involved in approach behaviour and the right hemisphere avoidance behaviour). In the present study we examined lateralised changes in TMT in response to social interaction in 10 Garnett's bushbabies. Additionally, we examined whether handedness could be used as a predictor of approach–avoidance tendencies. We found a positive association between temperature change and both allogrooming and affiliative approach. Social behaviour did not differ between right- and left-handed bushbabies. These findings are discussed in terms of existing theories of asymmetric emotional processing. Overall, the data suggest that there is a left hemisphere specialisation for processing approach-related behaviours, which is consistent with existing models of lateralised emotional processing. Our data also indicate that TMT is a reliable, cost-effective measure of cerebral activation that is less invasive and more practical than alternative measures such as EEG, PET, and fMRI.

Lateralized changes in tympanic membrane temperature in relation to different cognitive tasks in chimpanzees (Pan troglodytes).

Lateralized changes in tympanic membrane (TM) temperature were assessed in chimpanzees. Subjects were engaged in 1 of 3 different cognitive tasks, including matching-to-sample, visual-spatial discrimination, and a motor task. During execution of each task, TM temperatures were taken from each ear over a 20-min time period. The TM temperatures at each time interval were subtracted from a baseline measure to assess relative change in blood flow. For the matching-to-sample and visual-spatial discrimination tasks, significant lateralized changes in TM temperature were found, with left-ear temperature increasing and right-ear temperature decreasing. No laterality effects were found for the motor or control tasks. These data provide the first evidence of laterality in physiological functioning in chimpanzees and suggest that transient asymmetries in cognitive functions are associated with changes in cerebral blood flow as assessed by TM temperature change.

Lateralized changes in tympanic membrane temperature in relation to different cognitive tasks in chimpanzees (Pan troglodytes).

Lateralized changes in tympanic membrane temperature in relation to different cognitive tasks in chimpanzees (Pan troglodytes).

THERMOREGULATORY ADJUSTMENT DURING PREGNANCY PROTECTS FETUS FROM EXPOSURE OF EXERCISE-INDUCED HYPERTHERMIA 565

The purpose of this study was to determine whether moderate exercise determined by RPE during pregnancy elevates the deep trunk temperature of the mother, thus may expose the fetus to a potential hyperthermia. A total of 20 healthy women (10 pregnant; 10 non-pregnant), participated the study. Pregnant women's gestatio at the time of the data collection was 27 ± 7 week(mean ± SD). The Branching protocol with a treadmill was applied to reach the steady state at RPE 13 for 30 min. Body temperature (C°) was measured at the auditory canal, the back, the chest, and the rectum simultaneously at 5 minutes intervals before, during, after exercise, and until subjects reached to the resting values. Heart rate was also measured at 5 minutes intervals. The times at which each subject started sweating and returned to the resting core temperature were also recorded. Between two groups, there were no differences in age (29 ± 4 vs. 34 ± 11 years old. Body Mass Index (26 ± 4 vs. 24 ± 4),%Body Fat (30± 4 vs. 29 ± 4), time required to start sweating (10 ± 4 vs. 9 ± 8 min), and time to return to resting rectal temperature (38± 15 vs. 37 ± 16 min). Our results show that while skin temperature was higher in pregnant women during resting (34.4 ± 1.1 vs. 32.5 ± 1.8; p <.05) and exercising (33.0 ± 1.3 vs. 31.5± 1.8; p <.05), rectal temperature was lower in pregnant women during resting (37.1 ± 5 vs. 37.6 ± 3;p <.05) and exercising(37.5 ±.2 vs. 38.1 ±.2; p <.001). The exercise lowered skin temperature by 1 °C and elevated rectal temperature by.5 °C for both groups and caused no changes in tympanic membrane temperature, possibly indicating RPE 13 induced similar thermal changes for pregnant and non-pregnant women and that tympanic membrane temperature which reflects hypothalamic temperature was not affected by an acute exercise. We conclude that physiologic adjustment to pregnancy creates favorable thermal environment for fetus by increasing skin temperature and decreasing deep trunk temperature.

Mild resuscitative hypothermia and outcome after cardiopulmonary resuscitation.

Recovery without residual neurological damage after cardiac arrest with global cerebral ischemia is still a rare event. Severe impairment of bodily or cognitive functions is often the result. The individual, emotional, and social aspects of brain damage and rehabilitation are seldom taken into account. Efforts to improve the prevention of brain damage immediately after successful resuscitation of patients are missing. The efficacy of hypothermia in preserving neurologic function when instituted before and during certain no-flow cardiovascular states has been well documented both clinically and experimentally since the 1950s. Most studies have used moderate (28-33 degrees C) to deep (20-28 degrees C) hypothermia to demonstrate these protective effects. Considering the use of hypothermia for preservation and resuscitation, the lack of controlled outcome trials, the long period of time required to reach therapeutic hypothermia, and the incidence of rewarming complications such as infection, arrhythmia, and coagulopathy have made it difficult to apply these methods to emergency situations such as cardiac arrest. Recent experimental evidence in dogs has shown that hypothermia induced after cardiac arrest does indeed mitigate the effects of the postresuscitation syndrome and improves neurologic function and reduces histologic brain damage. More importantly, such benefits can be demonstrated with mild (34-36 degrees C) hypothermia, thus minimizing complications and requiring less time for induction of hypothermia. Ice water nasal lavage, direct carotid infusion of cold fluids, use of a cooling helmet, and peritoneal cooling are promising techniques for clinical cerebral cooling. External auditory canal temperature (e.g., tympanic membrane temperature changes) could provide an approximation to brain temperatures. For accurate temperature monitoring, however, a central pulmonary artery thermistor probe should be inserted. Temperature monitoring is needed to avoid temperature < 30 degrees C. Mild hypothermia may prove to be an important and secure component for cerebral preservation and resuscitation during and after global ischemia; it may also prove to be a useful method of cerebral resuscitation after global ischemic states, thereby promoting the prevention of neuromental diseases.

Tympanic Temperature Should Not be Used to Assess Exercise Induced Hyperthermia

Because of its easy access, tympanic membrane temperature has enjoyed increasing popularity as an index of deep core temperature during exercise as well as during recovery from exercise. These measurements are made with the assumption that changes in tympanic membrane temperature reflect changes in deep body temperature and, therefore, can be used as an index for the treatment of hyperthermia. In the present study, we report measurements of tympanic, esophageal and skin temperature in subjects exercising at constant (n = 6) or incremental (n = 4) work loads, and during recovery from exercise. Fanning of the upper chest was applied during recovery in two of the subjects who repeated the constant load exercise. Tympanic temperature was lower than esophageal during constant and incremental load exercise (p < 0.025 and p < 0.05, respectively). For both constant and incremental load exercise, there was a delay in the increase in tympanic temperature and the magnitude of the change was less than that of esophageal temperature. Furthermore, during recovery from steady state exercise, while tympanic and skin temperatures still increased, esophageal temperature readily decreased. Finally, because fanning influenced both tympanic and skin temperature changes and had little effect on esophageal temperature, we conclude that tympanic membrane temperature is influenced by rapid changes in skin temperature and should not be used to assess the thermal state of athletes during exercise or during recovery from exercise.

Effect of respiratory rate, respiratory depth, and open versus closed mouth breathing on sublingual temperature

The effect of open mouth breathing, tachypnea, and hyperpnea, either alone or in combination, on sublingual and tympanic membrane temperature in healthy adults was investigated. Seventy-eight subjects maintained randomly assigned breathing patterns for 15 minutes. Temperatures were monitored immediately prior to and for 5 minutes following the breathing protocol. The only statistically significant finding (p less than .01) was a lower sublingual temperature with open mouth breathing. No significant changes in tympanic membrane temperature were seen.

Inaccuracy of Liquid Crystal Thermometry to Identify Core Temperature Trends in Postoperative Adults

In 71 adult postsurgical patients, simultaneous measurement of core (tympanic membrane) and shell (liquid crystal adhesive temperature strip) cutaneous temperature was assessed on admission and every 15 minutes throughout the recovery room stay. Tympanic membrane sensors were inserted into the ear and adhesive temperature strips were applied to the forehead. Although temperature strip temperatures on admission to the recovery room were correlated significantly with tympanic membrane temperatures on admission to the recovery room (r = 0.61, p less than 0.001), subsequent readings 15, 30, 45, and 60 minutes after admission demonstrated decreasing correlation coefficients. Moreover, changes in temperature strip temperatures over the first 15, 30, and 45 minutes of monitoring in the recovery room did not correlate significantly with changes in tympanic membrane temperatures over the same time period. These data suggest that shell temperature (temperature strip) is not a reliable or valid trend indicator of core temperature (tympanic membrane) in postanesthetic adults.

Effect of head skin temperature on tympanic and oral temperature in man.

Five subjects were sequentially heated and cooled in a double-climate chamber while mean skin temperature (except the head) and head skin temperature were separately varied. The tympanic membrane temperatures of these subjects were disproportionately influenced by changes in head skin temperature. By heating and cooling localized regions of the head, changes in tympanic membrane temperature that followed changes in skin temperature on the ipsilateral side of the head could be produced. During heating of the head, oral and tympanic membrane temperatures were influenced to a similar degree, while esophageal temperature remained essentially unaffected. However, under conditions in which the legs and feet were heated in a water bath, esophageal temperature showed more rapid changes than either tympanic membrane or oral temperature. These findings suggest that tympanic membrane temperature and, to a lesser degree, oral temperature may be affected by thermal exchange occurring between arteries and veins in the cervical and cephalic regions. In addition, the ability to influence selectively esophageal and tympanic membrane temperatures brings into question the arbitrary use of these measurements under widely different experimental conditions as estimates of core temperature.

EFFECTS OF COOLING AND WARMING OF THE COMMON CAROTID ARTERIES ON THE BRAIN AND TYMPANIC MEMBRANE TEMPERATURES IN THE RABBIT

The thermal change in the hypothalamus, the thermoregulatory center, of the experimental animals has been usually measured by use of a thermocouple or a needleformed thermistor inserted through the skull and the brain parenchyma. However, these procedures may be unsuitable for a longterm, observation of the body temperature because the insertion of the thermodes causes considerably widespread damage of the brain tissues, particularly the hypothalamus. Recording the intracardiac, rectal and muscular temperatures of the rabbit by means of the thermistor equipped on the apex of the venous catheter or of the metal-needle, Yasuda (1-3) of this laboratory has reported the influence of various pyrogenic substances on the temperature. Using the same technique, Takashima (4) has compared the effects of pyrogenic substances in the intact and the liver-damaged rabbits. There exist some reports on the tympanic membrane temperature. Benzinger (5) has chosen the tympanic membrane of a human for the measurement of internal body temperature as close as feasible to the hypothalamic heat center. He has introduced 36-gauge twin wires of copper and constantan into the external auditory canal and has placed the thermoelectric junction of the wires at the tympanic membrane. But little work has been done to study the correlation between the brain temperature and the tympanic membrane temperature. The present experiments have been designed to determine whether the tympanic membrane temperature changes in parallel with the hypothalamic temperature or not. In these experiments a decline of the tympanic membrane and brain temperatures was produced by cooling the common carotid arteries or by the administration of some hypothermic agents. An elevation of the temperature was produced by the carotid warming or by the administration of pyrogenic substances. Moreover, the influences of the carotid cooling and warming on behaviors, respiration, blood pressure and heart rate were studied.