Initial Body Temperature Research Articles

Influence of Pre-Cooling on Skill Performance During Intermittent Exercise in the Heat

Skill performance deteriorates as hyperthermia develops during intermittent exercise in the heat. As pre-cooling lowers initial body temperature, it may play a role in improving skill performance during intermittent exercise in hot ambient conditions. However, there has been no little or no examination of this proposal. PURPOSE: To examine the influence of whole body pre-cooling on skill performance during simulated squash match play in the heat. METHODS: Six male squash players (22 ± 3 yr, 181 ± 5 cm, 75 ± 4 kg) were either pre-cooled for 60 min in a cool water shower or rested for 60 min before performing a skill test (ST 1), a 55 min simulated squash match in the heat (air temperature 28°C) and a second skill test (ST 2). By replicating shots performed in a match, skill performance was assessed using accuracy of a squash ball hitting pre-determined targets on the court floor. Comparisons between conditions were performed using a paired t statistic and simple, standardised effect size (ES). We also calculated the probability that the true population effect was practically significant (defined as one hit or one error) and interpreted this using a scale of qualitative descriptors and 90% confidence intervals (CI). RESULTS: Pre-cooling did not affect shot accuracy in ST 1, with no change in either targets hit (5 ± 2 hits vs. 5 ± 2 hits; p = 0.741; ES = 0.1) or errors (9 ± 4 errors vs. 10 ± 3 errors; p = 0.910; ES = 0.0). Pre-cooling was found to diminish the skill decrement seen at the end of intermittent exercise in heat, with increased targets hit (5 ± 3 hits vs. 2±1 hits; p = 0.004; ES = 3.0) and reduced failure (9 ±4 errors vs. 13 ± 4 errors; p = 0.016; ES = 0.9). This indicates that the pre-cooling is ‘almost certainly' (99% probability; 90% CI 2.2 to 5.1) and'very likely'(98% probability; 90% CI-5.7 to-1.6) to be practically beneficial, respectively. Throughout exercise, core temperature was lower (37.7 ± 1.0°C vs. 38.4 ± 0.9°C; p = 0.001; ES = 0.8) and heat storage was greater (373 ± 61 W-nrz vs. 299 ± 43 W-nr2; p = 0.006; ES = 1.7) following pre-cool, which concomitantly attenuated heart rate (161 ± 15 beats-mirr1 vs. 165 ±15 beats-min1: p = 0.008; ES = 0.3) and perceived exertion (14 ±2 vs. 16 ± 2; p = 0.001; ES = 1.0). CONCLUSION: Whole body pre-cooling is associated with improved skill performance at the end of simulated squash match play in the heat, which may be linked to a reduced thermoregulatory and perceived strain.

Low levels of hypohydration and endurance capacity during heavy exercise in untrained individuals

Untrained subjects ( n = 6 ) performed three cycle exercise trials at 80% maximal O 2 uptake until exhaustion in a climatic chamber (32 °C, 60% relative humidity) under the following three conditions: (1) 2% hypohydration, (2) 1% hypohydration, and (3) euhydration. Exercise tolerance time averaged 7.7±1.5, 14.0±2.4, and 20.9±3.7 min, respectively, under these three conditions. Endurance capacity in untrained individuals is substantially impaired even at low levels of hypohydration during heavy exercise in a compensable hot environment, and this impairment is associated with hypohydration-induced higher initial body temperatures that leads to earlier attainment of a critical core temperature.

How septic is urosepsis? Clinical course of infected hydronephrosis and therapeutic strategies

Despite rapid decompression of the upper urinary tract, some patients show signs of systemic inflammatory response syndrome (SIRS) or septic shock syndrome when infected hydronephrosis is diagnosed. Clinical and biological parameters were analyzed retrospectively in 189 patients diagnosed with hydronephrosis regarding disease severity as well as microbiological and antibiotic features. Fifty of the 189 patients had positive urine culture in the renal pelvis and were included in the study. Fifteen patients had to be placed in the intensive care unit and two patients developed severe septic signs. An initial body temperature above 38.5 degrees C (P=0.0004) and an elevated BMI (P=0.002) were the only parameters that indicated a higher risk of developing SIRS or sepsis. Typical biological parameters were not helpful in differentiating patients who will develop urosepsis. Further research is necessary to provide conclusive evidence of the value of other early prognostic markers in patients with infected hydronephrosis.

Risk factors influencing inadvertent hypothermia in infants and neonates during anesthesia

The factors affecting the thermal status in neonates and infants undergoing general anesthesia are not yet investigated in detail. We evaluated the factors leading to intraoperative hypothermia in 60 neonates and infants. The initial body temperatures and the core temperatures at the 10th, 30th, 60th and 90th minute of anesthesia, as well as at the end of the operation were recorded. The patients were divided into the groups according to the age, type of surgery (minor vs major), operating room (OR) temperatures (low '<23 degrees C' vs high '>23 degrees C') and the initial core temperature of the patients. In 31 neonates and 29 infants, the mean core temperatures decreased 10 min after anesthesia induction. In all neonates and in infants with 'low OR temperature' (<23 degrees C), these decreases continued to the end of the surgery. Except infants undergoing minor surgery, in all patients, the core temperatures at the end of surgery were lower than the baseline temperature. The greatest decrease in core temperatures occurred in neonates undergoing major surgery and with low OR temperature. In low OR temperature, the decrease of core temperature is higher in patients with major surgery. In patients undergoing minor surgery, the decrease of core temperature is more in neonates than infants. Major surgery increased the chance of decrease of the core temperature by 2.66 times and operating room temperature less than 23 degrees C by 1.96 times. The type of surgery and the OR temperature are the main factors for decrease of the core temperature in neonates and infants. In neonates, the core temperatures are less stable, regardless of OR temperature and type of surgery. In high OR temperature, infants can stabilize their core temperature better than neonates.

COMPARING CORRELATED PARAMETER ESTIMATES FOR NONLINEAR PET MODEL

The nonlinear PET model based on Newton's law of cooling can be used to estimate body temperature in cattle, T b challenged by hot cyclic chamber temperatures, T a . The PET model has four biologically meaningful parameters: K, the thermal constant; Δ, the difference between T b and adjusted T a ; Υ the proportion of variation in T b comparable to variation in Ta ; T bini, the initial body temperature. The two parameters Y and Δ are highly correlated in the current version of the model. This study looks at other ways to parameterize the PET model in an effort to reduce the correlation between parameters and improve nonlinear behaviors, such as parameter-effects curvature, bias, excess variance and skewness.

Effects of initial (larval) size and host body temperature on growth in trematodes

For ectotherms, temperature is an important correlate of variation in body size within species. Variation in body size among related species could also be attributable in part to temperature if the different species grow under different thermal regimes. The roles of both initial (larval) size and host body temperature on final (adult) size of parasitic trematodes were investigated in a comparative analysis. Trematodes are a good model group for such a study, with almost half of known species growing at high and constant temperatures in endothermic vertebrates and the rest at lower and fluctuating temperatures in ectothermic vertebrates. The relative growth of trematodes, i.e., their growth relative to the size of their larvae, varied greatly among species. Increases in body size from the cercarial larval stage to the adult stage averaged almost 40-fold (maximum 1300-fold), whereas increases in size from the metacercarial stage to the adult stage averaged 6-fold (maximum 110-fold). There were no differences between trematodes in ectothermic hosts and trematodes in endothermic hosts with respect to these measures of relative growth, however, which suggests that host type and the thermal regime provided by the host have no effect on the growth of trematodes from larval to adult stages. In contrast, the final (adult) body size of trematodes appears to be determined to some extent by their initial (larval) size, independently of the type of host in which they developed.

A Comparative Study of Three Warming Interventions to Determine the Most Effective in Maintaining Perioperative Normothermia

A Comparative Study of Three Warming Interventions to Determine the Most Effective in Maintaining Perioperative Normothermia

Does prehospital fluid administration impact core body temperature and coagulation functions in combat casualties?

Background: Administration of large amounts of fluids to trauma patients, in the absence of surgical control, may increase bleeding, cause hypothermia and coagulopathy which may worsen the bleeding and increase morbidity and mortality. The purpose of our study is to examine the impact of prehospital fluid administration to military combat casualties on core body temperature and coagulation functions. Methods: Prospective data were collected on all cases of moderately (9≤ISS≤14) and severely (ISS≥16) injured victims wounded in South Lebanon, treated by Israeli military physicians and evacuated to hospitals in Israel, over a two-year period. Data regarding prehospital phase of injury (timetables, amount of fluids) and upon hospital arrival (initial core body temperature, prothrombin time [PT], partial thromboplastin time [PTT]) were examined for monotonic relation using Spearman's non-parametric test. Results: Fifty-three moderately injured and 31 severely injured patients were included in the study. The average evacuation time for the moderately injured group was 109.3±44.8 min, and for the severely injured 100.3±38.4 min ( P value=NS). The mean volume of fluids administered was 2.39±1.52 and 2.49±1.47 l, respectively ( P=NS). No statistical correlation was found between core body temperature, PT or PTT, measured upon hospital arrival, and prehospital fluid treatment. In addition, no correlation was found between core body temperature on hospital arrival and prehospital time, or between prehospital fluid volumes and prehospital time. The mean core body temperature of the moderately injured patients was 36.8 °C, and that of severely injured was 35.8 °C ( P=0.026). Conclusions: With proper control of blood loss and avoidance of excessive fluid administration, moderately and severely injured combat casualties in ‘low intensity conflict’ in South Lebanon can be resuscitated with fluid volumes that do not result in a coagulation deficit or hypothermia. The core body temperature on arrival at the hospital is related to the severity of the injury.

Mastoïdites aiguës extériorisées de l’enfant : à propos d’une série de 48 cas

Design. – To determine the impact of the emergence of penicillin-resistant strains of pneumococci on the frequency of acute mastoiditis in children, and to assess the importance of laboratory and imaging studies in the treatment of acute mastoiditis. Method. – Retrospective review of the medical records of children with postauricular swelling and otoscopic signs of acute otitis media from January 1993 through December 2000. Results. – Forty-eight children aged three months to 14 years (median 17 months) were identified. The number of cases was almost the same from one year to another. All children had bacteriological examinations. The mastoid pus and the otorrhea was sterile in 22 cases. The most frequent pathogen was Streptococcus pneumoniae (17 cases), which was resistant to penicillin in 71 % of cases. The initial body temperature, the number of polymorphonuclears and the CRP were not different between the group of 18 children with periostitis, which required medical treatment alone, and the group of 30 children who had a mastoid abscess which required surgery. The difference between periostitis and mastoid abscess was seen on clinical examination and CTscan.

Symposia

We examined, in a controlled design, potential alterations in body temperature of male schizophrenic patients following acute antipsychotic drug (APD) administration. Fourteen drug-free (study group) and seven schizophrenic patients maintained on APDs (comparison group) initiated or received higher dose of their APD, respectively, for 27 days. Initial body temperature was 0.36°C higher in the study group (P=0.01) and decreased within 24 h to values comparable to that of the comparison group (all within normal range).

Stroke Severity Determines Body Temperature in Acute Stroke

Several studies have claimed that temperature on admission is of prognostic significance in acute stroke. Experimental studies showing that hyperthermia increases infarct size have lent credibility to this assumption. The aim of the present study was to test the hypothesis that initial body temperature is of importance for stroke outcome. This prospective study included 725 consecutive patients, 584 with cerebral infarcts and 141 with intracerebral hemorrhages, admitted to an acute stroke unit within 6 hours of stroke onset. Time of stroke onset and time of admission were recorded. Body temperature was measured on admission and every 2 hours during the first 24 hours. Patients were divided into 2 groups on the basis of stroke severity on admission: Scandinavian Stroke Scale Score (SSS) </=25 was defined as major stroke, and SSS >25 was defined as mild to moderate stroke. On admission, mean body temperature was normal. In the major stroke patients, body temperature started to rise 4 to 6 hours after stroke onset. At 10 to 12 hours after stroke onset, increased body temperature was found to be related to poor outcome. In mild to moderate stroke, there was no significant rise in temperature. Initial temperature >37.5 degrees C was not related to stroke severity or stroke outcome. In major stroke, a significant rise in temperature occurred hours after stroke onset. Severe infarcts and intracerebral hemorrhages caused temperature to rise, whereas initially increased temperature had no influence on stroke severity. Elevated body temperature on admission within 6 hours of stroke onset had no prognostic influence on stroke outcome at 3 months.

Acute antipsychotic drug administration lowers body temperature in drug-free male schizophrenic patients

We examined, in a controlled design, potential alterations in body temperature of male schizophrenic patients following acute antipsychotic drug (APD) administration. Fourteen drug-free (study group) and seven schizophrenic patients maintained on APDs (comparison group) initiated or received higher dose of their APD, respectively, for 27 days. Initial body temperature was 0.36°C higher in the study group ( P=0.01) and decreased within 24 h to values comparable to that of the comparison group (all within normal range).

Hypothermic cardiac arrest: An 11 year review of ED management and outcome

The purpose of this study was to examine the emergency department (ED) management of hypothermic cardiac arrest and its outcome. The medical records of all patients with hypothermic cardiac arrest treated in the ED from January 1, 1988 to January 31, 1999 were retrospectively reviewed. Data collected included initial body temperature, serum potassium, methods of rewarming, return of perfusing rhythm, and morbidity and mortality. Data were analyzed by descriptive methods. Eleven patients were treated in the ED resuscitation room for hypothermic cardiac arrest. Six patients were found in cardiac arrest in the field, one patient arrested during transport, and four patients arrested after ED arrival. The average initial temperature was 79.1°F (range 69.0°F to 86.7°F). Seven patients received an ED thoracotomy with internal cardiac massage and warm mediastinal irrigation. Four patients had airway management in the ED and then direct transport to the operating room for cardiac bypass rewarming. Three of the seven patients who received an ED thoracotomy subsequently went to intraoperative cardiac bypass rewarming. Five of the seven (71.4%) patients who received an ED thoracotomy survived, versus none of the four patients (0%) who went directly to intraoperative cardiac bypass. A direct comparison of immediate ED thoracotomy versus intraoperative cardiac bypass without ED thoracotomy is cautiously made as this was an unmatched and nonrandomized study. Three of the surviving patients underwent intraoperative cardiac bypass rewarming after receiving an ED thoracotomy. In two of these patients a perfusing rhythm had been established after thoracotomy in the ED and before transport to the operating room for cardiac bypass. Only one of seven (14.3%) patients who arrested prehospital survived versus four of four (100%) who arrested in the ED. ED thoracotomy with internal cardiac massage and mediastinal irrigation rewarming is effective in the management of hypothermic cardiac arrest. (Am J Emerg Med 2000;18:418-422.

Behavioral rise in body temperature and tachycardia by handling of a turtle ( Clemmys insculpta)

Three turtles, Clemmys insculpta, were kept together in a terrarium in a climatic chamber at 18°C, with lights on at 07:00 h and off at 19:00 h. In one corner of the terrarium an infrared lamp produced an operative temperature of 42.5°C, thereby allowing behavioral temperature regulation during the light period. When the turtles were handled only once a day for the purpose of taking cloacal temperature, their body temperature held stable at about 22–23°C. Immediately after being handled the turtles sought the radiant heat and regulated their body temperature at about 4°C higher than before the handling. When repeatedly handled every 15 min for 2 h the turtles maintained a high body temperature by their behavior. When not repeatedly handled the turtles returned to their initial preferred body temperature ca 22–23°C within 2 h. It is hypothesized that handling causes in turtles a fever similar to that observed in stressed mammals. The turtles were equipped with an electrocardiogram radio transmitter and their heart rate was recorded at a distance. Heart rate in undisturbed turtles was 28.3±0.6 bt/min. During a 1-min handling, their heart rate rose to 40.2±0.8 bt/min. This tachycardia persisted several minutes, then their heart rate returned to the baseline value in ca. 10 min. Stress fever and tachycardia are taken as signs of emotion in turtles.

Stroke: Neurologic and Functional Recovery The Copenhagen Stroke Study

Neurologic and functional recovery is dependent on a large variety of factors such as initial stroke severity, body temperature and blood glucose in the acute phase of stroke, stroke in progression, and treatment and rehabilitation on a dedicated stroke unit. The most important factor for recovery remains the initial severity of the stroke. In unselected patients 19% of the strokes are very severe, 14% are severe, 26% are moderate, and 41% are mild. In survivors, neurologic impairment after completed rehabilitation is still severe or very severe in 11%, moderate in 11%, mild in 47%, and 31% have achieved normal neurologic function. The ability to perform basic activities of daily living initially is reduced in three out of four patients with stroke. Most often affected is the ability to transfer, dress, and walk. After completed rehabilitation the group with moderate and severe disability is reduced from 50% to 25%, and the group with mild or no disability is increased from 50% to 75%. The prognosis of patients with mild or moderate stroke generally is excellent. Patients with severe stroke have a very variable recovery. Although the prognosis of patients with the most severe stroke is generally poor, one third of the survivors in this group are able to be discharged back to their own homes with no or only mild disability, if rehabilitated on a dedicated stroke unit. Functional recovery generally was completed within 3 months of stroke onset. Patients with mild stroke, however, recover within 2 months, patients with moderate stroke within 3 months, patients with severe stroke within 4 months, and patients with the most severe strokes have their functional recovery within 5 months from onset. Functional recovery is preceded by neurologic recovery by a mean of 2 weeks.

When to come out from a refuge: risk-sensitive and state-dependent decisions in an alpine lizard

Prey often respond to predator presence by increasing their use of refuges. However, unfavorable thermal conditions in refuges might entail physiological costs for an ectothermic prey. Thus, the decision of when to come out from a refuge should be optimized by considering the expected fitness effects of diminution of predation risk with time, but also by considering the cost of the loss of time spent at optimal body temperature maximizing physiological functions. The model of Ydenberg and Dill describes the trade-off between risk and cost for a prey fleeing to a refuge. We present a special case of this model to predict how emergence time from the refuge in lizards or other ectotherms should vary as a function of risk of predation and thermal costs of refuge use. The analyses of the variation in emergence time from a refuge of Lacerta monticola lizards in the field under two different predation risk levels supported the predictions of the model. As predicted, time spent in the refuge was longer when the threat of the initial attack had been higher, and therefore the subsequent diminution of risk was slower, but only when lizards emerged at the same place where they hid. When initial body temperature was high, some lizards decreased emergence time by emerging from a different place. In addition, the effects of thermal costs were more relevant in the highrisk situation. Time spent in the refuge under high risk increased when thermal conditions of the refuge were more similar to thermal conditions outside (i.e., physiological costs of refuge use were lower). We conclude that optimization of refuge-use strategies might help lizards cope with changes in predation risk without incurring excessive physiological costs. Key words: antipredator behavior, decision rules, ectotherms, hiding behavior, Lacerta monticola, lizards, predation risk, refuge use. [Behav Ecol 10:487‐492 (1999)]

The relationships of body temperature to weight gain, feed consumption, and feed utilization in broilers under heat stress

Commercial broiler males were used to evaluate body temperature response to heat stress and its relationship to gain, feed consumption, and feed conversion ratio. Individual gain, feed consumption, and feed conversion ratio were obtained from 28 to 49 d in a heat stress environment (32 C) and compared to a 21 C environment. Body temperatures were measured at 28, 35, and 42 d, then daily from 43 to 48 d, and correlated with 28 to 49 d gain, feed consumption, and feed conversion ratio. Feather cover was measured at 51 d of age as a percentage of BW. Initial 28-d body temperature was not significantly different between 21 and 32 C. Body temperature was significantly higher in the 32 C environment after 7 d of heat stress and was significantly higher than at 21 C at all points through 21 d of heat stress, with mean differences ranging from 0.5 to 1.0 C. Feather weight as a percentage of BW was significantly greater in the 21 C environment (6.22%) than the 32 C environment (5.03%). Mortality was not affected by the heat stress environment. Correlations between body temperature and gain, feed consumption, and feed conversion ratio were low and nonsignificant for most periods in the 21 C environment. In the 32 C environment, body temperature was significantly correlated with gain, feed consumption, and feed conversion ratio after 7 d of heat stress, with mean correlations of -0.40 for gain, -0.31 for feed consumption, and 0.24 for feed conversion ratio in Replicate 1 and -0.44 for gain, -0.40 for feed consumption, and 0.43 for feed conversion ratio in Replicate 2.

MDMA induced hyperthermia: a survivor with an initial body temperature of 42.9 degrees C.

A young male survived hyperpyrexia (42.9 degrees C) following MDMA ("Ecstasy") ingestion. He developed convulsions, rhabdomyolysis, metabolic acidosis, and respiratory failure. This was successfully managed by assisted ventilation, aggressive fluid...

Le test à l'indométacine permet-il d'orienter le diagnostic étiologique d'une fièvre isolée?

The aim of this study was to determine if evolution of fever after administration of indomethacin to febrile patients could separate those with fever of infectious origin from those with non-infectious origin. All patients with a rectal body temperature superior than 38 degrees C for at last 5 days and without any antibiotic or antipyretic therapy for more than 48 hours, were included in a 1 year prospective study. Each patient received one time 50 mg of indomethacin and rectal body temperature was obtained every 3 hours for 12 hours. Forty-five patients were included, 20 in group I (fever of infectious origin) and 25 in group II (fever of non-infectious origin). The mean age and mean initial body temperature were similar in the two groups. After administration of indomethacin, mean duration and mean amplitude of abatement of fever were similar in the two groups. Hypothermia was observed more frequently in group II (28%) than in group I (10%) (p < 0,05) and was preferentially associated to a malignant lymphoma. Also, diagnostic procedure with indomethacin is of little interest to separate fever of infectious origin from other, but hypothermia would suggest a fever due to a malignant lymphoma.

Risk Factors for Adverse Outcome in Persons With Pneumococcal Pneumonia

To identify risk factors for death and respiratory failure in persons with penicillin-sensitive pneumococcal bacteremia and pneumonia from data available at initial clinical evaluation. Retrospective chart review of persons with pneumococcal bacteremia and pneumonia. Tertiary care medical center (University of California Davis Medical Center, Sacramento). One hundred two consecutive adults admitted to the hospital for treatment of pneumococcal pneumonia with bacteremia. Of 102 persons, 25 (25%; 95% confidence interval [CI], 17 to 34%) died and 17 (16%; 95% CI, 10 to 25%) survived mechanical ventilation for respiratory failure. In univariate analyses, persons with preexisting lung disease (relative risk [RR], 2.0; 95% CI, 1.3 to 3.1), initial body temperature < 38 degrees C (RR, 2.1; 95% CI, 1.3 to 3.6), or nosocomial infections (RR, 2.5; 95% CI, 1.8 to 3.6) or who were > or = 48 years old (RR, 2.7; 95% CI, 1.5 to 4.8) were at greater risk for adverse outcomes than persons without these risk factors. Of 25 persons without these risk factors, only one (4%; 95% CI, 0 to 20%) died, and the remaining 24 persons did not require intensive care. Using these risk factors in a multivariate logistic model, death or respiratory failure would have been predicted in 67% of persons and better outcome predicted in 83% of the persons. In multivariate analysis, nosocomial infection was the greatest risk factor (adjusted odds ratio, 17.3; 95% CI, 3.1 to 98). Risk factors identified at hospital admission can predict the outcome in persons with pneumococcal pneumonia and bacteremia. Identifying these factors may allow earlier use of intensive care or more aggressive treatment. Independent of age, nosocomially acquired infections were the greatest risk factor for death or respiratory failure.