--- Gilles Potel <[EMAIL PROTECTED]> wrote: > ..parac�tamol peu efficace et en tout cas non �valu� dans cette > indication.. notre exp�rience actuelle est que c'est effectivement > peu efficace..
Je peut comprendre Mais je suis trop m�decine de brousse Pour ne pas donner d'antipyr�tiques dans ces cas l� Est-ce qu'il y'a un foyer infectueux d�clencheur/co-facteur ??? C'est comme avec la bronchiolite L'approche Rx/Dx J'aurais besoins d'�tre convaincu de l'effet n�faste des antip�rytiques avant de les retir�s des protocoles Certainement dans les premi�res heures Autrement il y'a une paucit� de certitudes quant aux "meilleures approches" Surprenant ! ! ! Dans les CATs : Emergency Department Care: � Heatstroke o Rapidly conduct initial stabilization of airway, breathing, and circulation. Administer supplemental oxygen and IV crystalloid while core temperature is determined and clothing is removed. o Institute aggressive cooling measures as rapidly as possible to minimize end-organ damage. An ideal goal is to drop the patient�s core temperature by 0.2�C/min. o Evaporative cooling is the preferred cooling method because it is safe, effective, easily accomplished, and well tolerated. Undress the patient, spray with tepid (not cold) water, and cool by large fans to maximize evaporative heat loss. o Ice water or slush immersion is an alternative cooling method. Although ice water or slush immersion is effective at rapidly lowering body temperature, it is associated with more complications than evaporative cooling and generally is not recommended. Immersion in ice water causes peripheral vasoconstriction, shunts blood away from the periphery, and leads to less heat dissipation. It also is uncomfortable for the patient, limits access for cardiac and vital sign monitoring, and may result in hypothermic overshoot. o Adjunctive measures include ice packs applied to the patient�s neck, axillae, and groin as well as cooling blankets. o Other modalities with anecdotal success include ice water gastric lavage, ice water rectal lavage, ice water peritoneal lavage, and cardiopulmonary bypass. http://www.emedicine.com/emerg/topic236.htm Heat stroke syndrome - most cases occur during periods of extreme ambient heat (during the summer months), especially when the patient has a limited ability to effectively manage heat or limit significant exposure to the heat - elderly patients, who live a sedentary lifestyle and who do not have adequate cooling systems at home are at greatest risk - especially if they suffer from obesity, co-morbid diseases, psychiatric illness or chronic substance abuse +/- taking certain predisposing medications eg. diuretics, anti-cholinergics, anti-hypertensive agents - prodromal symptoms of heat exhaustion (nausea, weakness, dizziness, headache, muscle cramps and confusion) may precede the full-blown heat stroke syndrome - hyperpyrexia + altered LOC are the dominant features, and significant rigidity is uncommon - anhidrosis and a "hot, dry skin" suggests the diagnosis, but anhidrosis may be a late and inconsistent finding (* diaphoresis is more common in NMS and SS) - hepatic damage with disproportionately high liver enzymes is also suggestive, and the urine may be brown and turbid resembling "machine oil" - complications include hypotension and distributive shock, high output cardiac failure, acute oliguric renal failure, coagulopathy and DIC http://www.homestead.com/emguidemaps/files/rigidity.htm#Heat%20stroke%20syndrome Dans les textes pertinents : Pour le coup de chaleur le concensus semble �tre que plus le refroidissement est rapide plus la mortalit� est r�duite. Cleve Clin J Med. 2001 Aug;68(8):685-7. Heat illness: tips for recognition and treatment. Waters TA. Department of Emergency Medicine, Cleveland Clinic Foundation, OH 44195, USA. [EMAIL PROTECTED] Heat stroke, an acute, life-threatening emergency, results from an overload or impairment of heat-dissipating mechanisms. At risk are the elderly, infants, the obese, people with hyperthyroidism, and those taking certain drugs. Early recognition and rapid cooling are essential--the more rapid the cooling, the lower the mortality. Dans les M�thodes et traitments : (Des documents sur la fi�vre inclus) Am J Crit Care. 2001 Jul;10(4):276-80. Comparison of fever treatments in the critically ill: a pilot study. Henker R, Rogers S, Kramer DJ, Kelso L, Kerr M, Sereika S. University of Pittsburgh Medical Center, Pa., USA. BACKGROUND: Fever in critically ill patients is often treated with antipyretics or physical cooling methods. Although fever is a host defense response that may benefit some critically ill patients, others may not tolerate the cardiovascular demands associated with fever. OBJECTIVES: To compare antipyretics and physical cooling for their effects on core body temperature and cardiovascular responses in critically ill patients. METHODS: The antipyretic administered was 650 mg of acetaminophen. Physical cooling was accomplished by anterior placement of a cooling blanket at 18 degrees C. Core temperature and cardiovascular responses were measured in 14 febrile (body temperature, 38.8 degrees C) critically ill patients at baseline before treatment and up to 3 hours after treatment. Patients able to receive acetaminophen were randomly assigned to receive either acetaminophen only (n = 5) or acetaminophen in combination with a cooling blanket (n = 3). Patients not able to receive acetaminophen were treated with physical cooling only (n = 6). RESULTS: Mean body temperature decreased minimally from baseline to 3 hours after treatment in the physical-cooling-only group (from 39.1 degrees C to 39.0 degrees C) and in the physical cooling and acetaminophen group (from 39.1 degrees C to 38.6 degrees C), but the mean body temperature increased in the acetaminophen-only group (from 39.2 degrees C to 39.4 degrees C). Other notable findings included a slight increase in systemic vascular resistance index in the physical-cooling-only group and in the physical-cooling-plus-acetaminophen group. CONCLUSIONS: Although the study included only 14 subjects, the findings will provide information for future studies in febrile critically ill patients. Nurs Crit Care. 2003 Jan-Feb;8(1):37-45. Cooling strategies for patients with severe cerebral insult in ICU (Part 2). Price T, McGloin S, Izzard J, Gilchrist M. Critical Care, University of the West of England, Bristol. [EMAIL PROTECTED] Critically ill patients who have sustained a severe cerebral insult will be actively cooled should they develop an elevated body core temperature. Patients who require therapeutic hypothermia for neuroprotection may require the same cooling strategies. A literature review suggested limited evidence to support cooling strategies currently used within one intensive care unit. An experimental approach was used to examine the effects of paracetamol and four external cooling strategies on patients with severe cerebral insult It is suggested that paracetamol is effective in reducing body core temperature and that fans may not. However, data obtained from the study of the four external cooling strategies were inconclusive. Clin Infect Dis. 1997 Jun;24(6):1208-13. Comment in: � Clin Infect Dis. 1997 Jun;24(6):1214-6. Use and effectiveness of hypothermia blankets for febrile patients in the intensive care unit. O'Donnell J, Axelrod P, Fisher C, Lorber B. Section of Infectious Diseases, Temple University School of Medicine, Philadelphia, Pennsylvania, USA. We performed a prospective observational (noninterventional) study of hypothermia blanket use in a population of adult intensive care unit patients with body temperatures of > or = 102.5 degrees F. Thirty-nine of ninety-four febrile episodes (in 83 patients) were treated with hypothermia blankets. Logistic regression revealed that the strongest independent predictors of hypothermia blanket use were a temperature of > or = 103.5 degrees F (odds ratio [OR] = 17), mechanical ventilation (OR = 25), and acute central nervous system illness (OR = 7.5). Hospitalization in the medical intensive care unit was strongly associated with avoidance of this therapy (OR = 0.023). Treatment with a hypothermia blanket was ordered by a physician in only 15% of cases. The mean cooling rate was the same (0.028 degree F/h) for blanket-treated and control patients. Multivariate Cox regression and factorial and repeated measures of analysis of variance revealed that blanket treatment was not more effective than other cooling methods. However, this treatment was associated with more "zigzag" temperature fluctuations of > or = 3 degrees F (56% of blanket-treated patients vs. 18% of control patients; P < .001) and rebound hypothermia (18% vs. 0; P = .001). Hypothermia blanket therapy is primarily a nursing decision. We conclude that in addition to being no more effective than other cooling measures, hypothermia blanket therapy was associated with more temperature fluctuations and with more episodes of rebound hypothermia. J Neurosci Nurs. 1990 Feb;22(1):19-24. Related Articles, Links A comparison of three methods of managing fever in the neurologic patient. Morgan SP. Southwest Florida Regional Medical Center, Ft. Myers 33902. Patients with neurological dysfunction can suffer fevers due to irritation of, or damage to the temperature-regulating center in the brain, or a combination of both. Although hypothermic therapy is a critical treatment nurses often perform, the most effective cooling method has not been studied in the neurological patient. The purpose of this quasi-experimental study was to compare the effectiveness of three methods of fever reduction, and the effect of each on patient shivering. Twenty-one adult febrile neurological patients were randomly placed in one of three temperature reduction groups. One of the temperature reduction protocols was initiated when a subject first became febrile. Rectal temperatures were taken every 15 minutes using an IVAC Temp-Plus thermometer until the subject's temperature returned to 100 degrees F. Subjects were observed for shivering throughout the procedures. The mean time necessary for the subject's temperature to return to 100 degrees F was calculated. A one-way analysis of variance of the time required to reach 100 degrees F was done to determine if a significant difference existed in rate of temperature reduction among the groups. The analysis revealed no statistically significant difference among the three methods, but a chi-square analysis indicated a significant relationship between shivering and the use of a hypothermia blanket. Am J Crit Care. 2001 Jan;10(1):52-9. Cooling by convection vs cooling by conduction for treatment of fever in critically ill adults. Creechan T, Vollman K, Kravutske ME. Henry Ford Hospital, Detroit, Mich., USA. BACKGROUND: Cooling with water-flow blankets, which are difficult to manipulate and interfere with patients' care, may be ineffective in controlling fever. OBJECTIVE: To compare the effectiveness of cooling via convective airflow blankets with cooling via conductive water-flow blankets for treatment of fever in critically ill adults. METHOD: A 2-group experimental design was used to compare cooling via convection (n = 20) with cooling via conduction (n = 17) in critically ill adults with an infection-related fever of 38.5 degrees C or greater. Esophageal temperature was measured every 15 minutes until a temperature of 38.0 degrees C was reached or 8 hours had elapsed. Alternative cooling measures were withheld unless the temperature increased to more than 40.0 degrees C. Data on nurses' satisfaction were collected, and complications related to each cooling method were examined. RESULTS: Temperatures decreased more rapidly in the airflow group (mean decrease, 0.377 degree C/h) than in the water-flow group (mean decrease, 0.163 degree C/h). A temperature of 38.0 degrees C was achieved more often in the airflow group (75% vs 47.1%). Fever (temperature > 38.5 degrees C) recurred sooner in the water-flow group (6.6 hours) than in the airflow group (22.2 hours). Both methods were easy to use. Compared with the water-flow blanket, the airflow blanket was recommended for future use twice as often and interfered less with patients' care. CONCLUSIONS: In critically ill adults with an infection or a suspected infection, cooling with an airflow blanket is more effective and more preferred for cooling than is cooling with a water-flow blanket. Nurs Res. 1992 Mar-Apr;41(2):68-72. Cooling effects and comfort of four cooling blanket temperatures in humans with fever. Caruso CC, Hadley BJ, Shukla R, Frame P, Khoury J. School of Nursing, University of Michigan, Ann Arbor. Adult patients with fever (N = 89) were randomized into four blanket temperature groups: 7.2, 12.8, 18.3, and 23.9 degrees C. With their extremities protected, subjects were given acetaminophen and placed between two cooling blankets. There were no differences in the mean time (in minutes) to cool to a body temperature of 38.9 degrees C among groups. Although there were no differences in mean time for shivering, a trend of less shivering was apparent with warmer blanket temperatures. Few patients shivered (n = 17). There were no differences in the mean time (in minutes) for afterfall among the groups. The mean amount of afterfall for the 7.2 degrees C group (1.04 degrees C, SD = 0.50) was significantly greater than the 23.9 degrees C group (0.68 degrees C, SD = 0.47). Comfort scores significantly improved with warmer blanket temperatures. Thus, warmer blanket temperatures provided similar rates of cooling as the colder temperatures, yet were perceived to be more comfortable by the patient. Clin Infect Dis. 1997 Jun;24(6):1208-13. Comment in: � Clin Infect Dis. 1997 Jun;24(6):1214-6. Use and effectiveness of hypothermia blankets for febrile patients in the intensive care unit. O'Donnell J, Axelrod P, Fisher C, Lorber B. Section of Infectious Diseases, Temple University School of Medicine, Philadelphia, Pennsylvania, USA. We performed a prospective observational (noninterventional) study of hypothermia blanket use in a population of adult intensive care unit patients with body temperatures of > or = 102.5 degrees F. Thirty-nine of ninety-four febrile episodes (in 83 patients) were treated with hypothermia blankets. Logistic regression revealed that the strongest independent predictors of hypothermia blanket use were a temperature of > or = 103.5 degrees F (odds ratio [OR] = 17), mechanical ventilation (OR = 25), and acute central nervous system illness (OR = 7.5). Hospitalization in the medical intensive care unit was strongly associated with avoidance of this therapy (OR = 0.023). Treatment with a hypothermia blanket was ordered by a physician in only 15% of cases. The mean cooling rate was the same (0.028 degree F/h) for blanket-treated and control patients. Multivariate Cox regression and factorial and repeated measures of analysis of variance revealed that blanket treatment was not more effective than other cooling methods. However, this treatment was associated with more "zigzag" temperature fluctuations of > or = 3 degrees F (56% of blanket-treated patients vs. 18% of control patients; P < .001) and rebound hypothermia (18% vs. 0; P = .001). Hypothermia blanket therapy is primarily a nursing decision. We conclude that in addition to being no more effective than other cooling measures, hypothermia blanket therapy was associated with more temperature fluctuations and with more episodes of rebound hypothermia. J Neurosurg Anesthesiol. 1997 Jul;9(3):250-5. Convection versus conduction cooling for induction of mild hypothermia during neurovascular procedures in adults. Theard MA, Tempelhoff R, Crowder CM, Cheng MA, Todorov A, Dacey RG Jr. Department of Anesthesiology, Washington University Medical Center, St. Louis, Missouri 63110, USA. Hypothermia for cerebral protection is usually achieved by administration of intravenous fluids at room temperature, cooling ambient air, ice packs, and a temperature-adjustable circulating water mattress. We compared cooling by conduction by using a water mattress to cool by convection by using a forced-air cooling device. Twenty patients were prospectively randomized to two groups: 10 patients cooled by convection (CC) and 10 patients cooled by traditional methods (TC). Two patients in the CC group were withdrawn from the study and excluded from the analysis; one patient for failure to cool despite the use of both techniques, and the other for the abrupt onset of arrhythmias and myocardial depression during hypothermia. Temperature was measured at the tympanic membrane, pulmonary artery, and esophageal probe sites and recorded every 15 min. The time required to reach the target temperature range of 33-34 degrees C was recorded. We found no differences in the temperatures measured at the three sites during cooling and rewarming. Baseline temperatures recorded from the pulmonary artery catheter before beginning "active cooling" were similar in both groups (TC, 35.0 +/- 0.2 degrees C vs. CC, 35.3 +/- 0.1 degrees C). We found no difference in the time to target temperature between TC and CC (TC, 178 +/- 25 min vs. CC, 142 +/- 21 min). One patient had some arrhythmias on cooling in the convective group, but her preoperative condition may have been responsible. In conclusion, cooling by convection appears to be a safe alternative to conduction cooling. R�f�rence r�cente sans r�sum� : : Am Fam Physician. 2003 Apr 1;67(7):1439-40; author reply 1440. Evaluation and treatment of heat-related illnesses. Khogali M. Les gadgets : Anesthesiology. 1997 Nov;87(5):1089-95. Efficacy of intraoperative cooling methods. Plattner O, Kurz A, Sessler DI, Ikeda T, Christensen R, Marder D, Clough D. Department of Anesthesia and Perioperative Care, University of California, San Francisco 94143-0648, USA. BACKGROUND: Patients may require perioperative cooling for a variety of reasons including treatment of a malignant hyperthermia crisis and induction of therapeutic hypothermia for neurosurgery. The authors compared heat transfer and core cooling rates with five cooling methods. METHODS: Six healthy volunteers were anesthetized with desflurane and nitrous oxide. The cooling methods were 1) circulating water (5 degrees C, full-length mattress and cover), 2) forced air (10 degrees C, full-length cover), 3) gastric lavage (500 ml iced water every 10 min), 4) bladder lavage (300 ml iced Ringer's solution every 10 min), and 5) ice-water immersion. Each method was applied for 40 min or until the volunteers' core temperatures approached 34 degrees C. The volunteers were rewarmed to normothermia between treatments. Core cooling rates were evaluated using linear regression. RESULTS: The first volunteer developed abdominal cramping and diarrhea after gastric lavage. Consequently, the technique was not again attempted. Bladder lavage increased heat loss approximately 10 W and decreased core temperature 0.8 +/- 0.3 degrees C/h (r2 = 0.99 +/- 0.002; means +/- SD). Forced-air and circulating-water cooling comparably increased heat flux, approximately 170 W. Consequently, core cooling rates were similar during the two treatments at 1.7 +/- 0.5 degrees C/h (r2 = 0.99 +/- 0.001) and 1.6 +/- 1.1 degrees C/h (r2 = 0.98 +/- 0.02), respectively. Immersion in an ice water slurry increased heat loss approximately 600-800 W and decreased core temperature 9.7 +/- 4.4 degrees C/h (r2 = 0.98 +/- 0.01). Immersion cooling was associated with an afterdrop of approximately 2 degrees C. CONCLUSIONS: Bladder lavage provided only trivial cooling and gastric lavage provoked complications. Forced-air and circulating-water cooling transferred relatively little heat but are noninvasive and easy to implement. Forced-air or circulating-water cooling, perhaps combined with intravenous administration of refrigerated fluids, may be sufficient in some patients. When noninvasive methods prove insufficient for rapid cooling, ice-water immersion or peritoneal lavage probably should be the next lines of defense. Crit Care Med. 2002 Nov;30(11):2481-8. Comment in: � Crit Care Med. 2002 Nov;30(11):2598-600. Safety and efficacy of a novel intravascular cooling device to control body temperature in neurologic intensive care patients: a prospective pilot study. Schmutzhard E, Engelhardt K, Beer R, Brossner G, Pfausler B, Spiss H, Unterberger I, Kampfl A. Department of Neurology, University Hospital Innsbruck, Austria. OBJECTIVE: To determine the safety and efficacy of a novel intravascular cooling device (Cool Line catheter with Cool Gard system) to control body temperature (temperature goal <37 degrees C) in neurologic intensive care patients. DESIGN: A prospective, uncontrolled pilot study in 51 consecutive neurologic intensive care patients. SETTING: A neurologic intensive care unit at a tertiary care university hospital. PARTICIPANTS: Patients were 51 neurologic intensive care patients with an intracranial disease requiring a central venous catheter due to the primary (intracranial) disease. We excluded patients under the age of 19 yrs and those with active cardiac arrhythmia, full sepsis syndrome, bleeding diathesis and infection, or bleeding at the site of the intended catheter insertion. Male to female ratio was 31:20, and the median age was 55 yrs (range, 24-85 yrs). Forty-four of 51 patients (86.3%) had an initial Glasgow Coma Scale score of 3, three patients had a Glasgow Coma Scale score of 9, one patient presented with an initial Glasgow Coma Scale score of 11, two patients had an initial Glasgow Coma Scale score of 13, and one patient had an initial Glasgow Coma Scale score of 15. The mean initial tissue injury severity score was 45.1 and the median initial tissue injury severity score 45.0 (range, 19-70). INTERVENTIONS: Patients were enrolled prospectively in a consecutive way. Within 12 hrs after admission, the intravascular cooling device (Cool Line catheter) was placed, the temperature probe was located within the bladder (by Foley catheter), and the Cool Gard cooling device was initiated. This Cool Gard system circulates temperature-controlled sterile saline through two small balloons mounted on the distal end of the Cool Line catheter. The patient's blood is gently cooled as it is passed over the balloons. The Cool Gard system has been set with a target temperature of 36.5 degrees C. The primary purpose and end point of this study was to evaluate the cooling capacity of this intravascular cooling device. Efficacy is expressed by the calculation formula of fever burden, which is defined as the fever time product ( degrees C hours) under the fever curve. MEASUREMENTS AND MAIN RESULTS: The cooling device was in operation for a mean of 152.4 hrs. The ease of insertion was judged as easy in 42 of 51 patients; in a single patient, the catheter was malpositioned within the jugular vein, requiring early removal. The rate of infectious and noninfectious complications (nosocomial pneumonia, bacteremia, catheter-related ventriculitis, pulmonary embolism, etc.) was comparable to the rate usually observed in our neurologic intensive care patients with such severe intracranial diseases. The total fever burden within the entire study period of (on average) 152.4 hrs was 4.0 degrees C hrs/patient, being equivalent to 0.6 degrees C hrs/patient and day. Thirty of 51 patients showed an elevation of the body temperature (>37.9 degrees C) within 24 hrs after termination of the cooling study. One awake patient (subarachnoid hemorrhage, Glasgow Coma Scale score 15) experienced mild to moderate shivering throughout the entire period of 7 days. The mortality rate was 23.5%. CONCLUSION: This novel intravascular cooling device (Cool Line catheter and Cool Gard cooling device) was highly efficacious in prophylactically controlling the body temperature of neurologic intensive care patients with very severe intracranial disease (median Glasgow Coma Scale score, 3-15). Morbidity and mortality rates were consistent with the ranges reported in the literature for such neurologic intensive patients. Transplant Proc. 2002 Nov;34(7):2602-3. Total body cooling using cardiopulmonary bypass for procurement from non-heart-beating donors. Koyama I, Shinozuka N, Miyazawa M, Watanabe T. Neurology. 2001 Feb 13;56(3):292-8. Comment in: � Neurology. 2001 Feb 13;56(3):286-7. Clinical trial of an air-circulating cooling blanket for fever control in critically ill neurologic patients. Mayer S, Commichau C, Scarmeas N, Presciutti M, Bates J, Copeland D. Division of Critical Care Neurology, Department of Neurology, Columbia University College of Physicians & Surgeons, New York, NY, USA. [EMAIL PROTECTED] OBJECTIVE: To evaluate the efficacy of an air-circulating cooling blanket for reducing body temperature in febrile neuro-ICU patients treated with acetaminophen. METHODS: Two-hundred twenty consecutively admitted neuro-ICU patients whose tympanic membrane temperature reached or exceeded 101 degrees F (38.3 degrees C) were randomly assigned to receive acetaminophen (650 mg every 4 hours) alone (n = 107) or acetaminophen plus air blanket therapy (n = 113). After 24 hours of treatment, the authors compared the proportion of subjects who attained treatment success (T < or = 99 degrees F) or treatment failure (T > or = 101 degrees F for 2 consecutive hours) using the chi(2) test and the time to reach these endpoints using Kaplan-Meier survival analysis. MAIN RESULTS: Air blanket therapy resulted in a small increase in the proportion of subjects with treatment success (44% versus 36%, chi(2) p = 0.19, log rank p = 0.10) and a similar small reduction in the proportion of patients with treatment failure (42% versus 53%, chi(2) p = 0.11, log-rank p = 0.21), compared with treatment with acetaminophen alone. Approximately one third of patients in both groups remained febrile after randomization and "failed" after the first 2 hours of treatment. Twelve percent of patients assigned to air blanket therapy refused or were unable to tolerate treatment, compared with 2% of patients treated with acetaminophen alone (p = 0.005). CONCLUSIONS: Treatment with an air-circulating cooling blanket did not effectively reduce body temperature in febrile neuro-ICU patients treated with acetaminophen. More effective interventions are needed to maintain normothermia in patients at risk for fever-related brain damage. Intensive Care Med. 2003 Jun;29(6):939-43. Epub 2003 May 01. Endovascular cooling with heat exchange catheters: a new method to induce and maintain hypothermia. Keller E, Imhof HG, Gasser S, Terzic A, Yonekawa Y. Department of Neurosurgery, Nordtrakt 1, University Hospital of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland. [EMAIL PROTECTED] OBJECTIVE: To test the convenience of a new cooling technique with intravenous heat exchange catheters. DESIGN: Retrospective chart review. SETTING: University hospital neurointensive care unit. PATIENTS: Twenty patients with severe subarachnoid hemorrhage Hunt and Hess Grade 3-5 treated with mild hypothermia. INTERVENTIONS: Cooling to reach target body core temperature (33 degrees C-34 degrees C) was induced as quickly as possible in all patients. In the first ten patients (group one) moderate hypothermia was induced and maintained using cooling blankets. In group two, an 8.5F heat exchange catheter was placed central venous and temperature-adjusted normal saline circulated in a closed-loop system entailing two balloons. MEASUREMENTS AND RESULTS: A total of 2,007 values of body core temperature (BCT) were registered every hour. Foley temperature catheters were used for monitoring BCT in the bladder. The time to reach the target BCT and the stability of temperature during hypothermia were compared between the two groups. No specific complications associated with the new cooling device were observed. Time to reach the target temperature in group two was significantly shorter than in group one (190+/-110 and 370+/-220 min) ( P=0.023). In group one significantly more temperature values were out of the target range (127 of 792 values; 16.0%) than in group two (62 of 1,215 values; 5.1%) ( P<0.0001). CONCLUSIONS: The new endovascular cooling technique seems to be superior for rapid induction of hypothermia and maintaining a more stable temperature than the cooling techniques using blankets and ice bags. S Afr Med J. 1986 Mar 15;69(6):378-80. Body cooling as a method for reducing hyperthermia. An evaluation of techniques. Kielblock AJ, Van Rensburg JP, Franz RM. The most important objective in the treatment of heatstroke and related conditions is to reduce the body core temperature to safe levels. Subjects performed at an external work rate of 54 W in hot, humid conditions (dry-bulb 40 degrees C, wet-bulb 35 degrees C), and a recent innovation to achieve body cooling, i.e. strategically placing instant cold packs (ICPs) (Coldpak; Medac) over the large vessels of the neck, axillae and groin, was evaluated under controlled laboratory conditions. We found that this procedure was not significantly more effective (P greater than 0.5) than passive body cooling in bringing about a 2 degrees C reduction in rectal temperature. Moreover, covering the whole body with ICPs plus induced evaporative cooling produced higher cooling rates than those achieved by the strategic placement of ICPs (0.0340 degrees C/min and 0.0344 degrees C/min respectively) (P less than 0.01). J Appl Physiol. 1999 Jul;87(1):54-73. The free-convective anomaly. Steadman RG. Department of Agricultural Sciences, La Trobe University, Bundoora, Victoria 3083, Australia. [EMAIL PROTECTED] Persons exposed to high temperature, or to equivalent environmental factors, have quantifiable reactions, such as reducing the resistance to both heat and moisture flow in skin tissues and clothing needed to maintain thermal equilibrium. The one-to-one relationship between this resistance in the walking person and temperature, with the other factors neutral, is the basis for the apparent temperature scale and the derived heat index. When this approach is taken to assess the thermal environment for a still person exposed to heat in still air, there is a zone of ambient conditions in which there are three solutions to the heat-balance equation. Extraordinary thermal stress occurs, depending slightly on other conditions, at ambient temperatures near 41 degrees C, especially at high humidity, because of the difficulty in carrying sweat vapor from the person when free convection is minimal. This anomaly is examined for a range of ambient vapor pressures and extra radiation. The rapid rise in heat stress when ambient temperature just exceeds body temperature in still conditions may explain the severity of some observed distress. Anesthesiology. 1995 Apr;82(4):870-6. Thermoregulatory vasoconstriction impairs active core cooling. Kurz A, Sessler DI, Birnbauer F, Illievich UM, Spiss CK. Department of Anesthesia, University of California, San Francisco, School of Medicine 94143-0648, USA. BACKGROUND: Many clinicians now consider hypothermia indicated during neurosurgery. Active cooling often will be required to reach target temperatures < 34 degrees C sufficiently rapidly and nearly always will be required if the target temperature is 32 degrees C. However, the efficacy even of active cooling might be impaired by thermoregulatory vasoconstriction, which reduces cutaneous heat loss and constrains metabolic heat to the core thermal compartment. The authors therefore tested the hypothesis that the efficacy of active cooling is reduced by thermoregulatory vasoconstriction. METHODS: Patients undergoing neurosurgical procedures with hypothermia were anesthetized with either isoflurane/nitrous oxide (n = 13) or propofol/fentanyl (n = 13) anesthesia. All were cooled using a prototype forced-air cooling device until core temperature reached 32 degrees C. Core temperature was measured in the distal esophagus. Vasoconstriction was evaluated using forearm minus fingertip skin-temperature gradients. The core temperature triggering a gradient of 0 degree C identified the vasoconstriction threshold. RESULTS: In 6 of the 13 patients given isoflurane, vasoconstriction (skin-temperature gradient = 0 degrees C) occurred at a core temperature of 34.4 +/- 0.9 degree C, 1.7 +/- 0.58 h after induction of anesthesia. Similarly, in 7 of the 13 patients given propofol, vasoconstriction occurred at a core temperature of 34.5 +/- 0.9 degree C, 1.6 +/- 0.6 h after induction of anesthesia. In the remaining patients, vasodilation continued even at core temperatures of 32 degrees C. Core cooling rates were comparable in each anesthetic group. However, patients in whom vasodilation was maintained cooled fastest. Patients in whom vasoconstriction occurred required nearly an hour longer to reach core temperatures of 33 degrees C and 32 degrees C than did those in whom vasodilation was maintained (P < 0.01). CONCLUSIONS: Vasoconstriction did not produce a full core temperature "plateau," because of the extreme microenvironment provided by forced-air cooling. However, it markedly decreased the rate at which hypothermia developed. The approximately 1-h delay in reaching core temperatures of 33 degrees C and 32 degrees C could be clinically important, depending on the target temperature and the time required to reach critical portions of the operation. Am J Emerg Med. 1993 Jan;11(1):1-3. Comment in: � Am J Emerg Med. 1995 Jan;13(1):119. Evaporation versus iced peritoneal lavage treatment of heatstroke: comparative efficacy in a canine model. White JD, Kamath R, Nucci R, Johnson C, Shepherd S. Department of Emergency Medicine, School of Medicine, Georgetown University Medical Center, Washington, DC. 20007. The authors compared the speed of cooling and treatment efficacy for evaporative cooling versus iced peritoneal lavage in a canine heatstroke model. Nine random-source, mongrel dogs were anesthetized, shaved, and internally heated until the core temperature reached 43.0 degrees C. The animals were then randomly assigned to be cooled to 37 degrees C either by sterile normal saline (6 degrees C) continuous peritoneal lavage at 250 mL/min (n = 4), or by spraying with tap water (15 degrees C, 12 L/min) before a large fan blowing room temperature air (23 degrees C) across the dog at 0.5 m/sec from a height of 50 cm (n = 5). Temperatures were monitored by thermocouples in both tympanic membranes. Electrocardiogram, blood pressure, and pulse were continuously monitored. Evaporative cooling was as rapid as iced peritoneal lavage (0.18 +/- .03 versus 0.17 +/- .07 degrees C/min/m2, P = NS). All animals survived, although one animal in each treatment group demonstrated a moderate neurologic deficit when measured 48 hours following resuscitation. A simple noninvasive evaporative cooling technique, readily available in the emergency department, appears to be as rapid readily available in the emergency department, appears to be as rapid and effective as aggressive peritoneal lavage for cooling and treating heatstroke in the dog. Aviat Space Environ Med. 1978 Jun;49(6):779-84. Peritoneal lavage cooling in an anesthetized dog heatstroke model. Bynum G, Patton J, Bowers W, Leav I, Hamlet M, Marsili M, Wolfe D. This study was undertaken to compare cooling in room air (27 degrees C, 20% RH), ice slush surface cooling, and peritoneal lavage cooling (6-10 degrees C) as methods for lowering body temperature in an anesthetized dog heatstroke model. We anesthetized 19 animals with sodium pentobarbital (25 mg/kg) intravenously, and maintained them in an ambient temperature of 42-46 degrees C with a water heating blanket approximately 2.0 h until rectal temperatures rose to 43.2 +/- 0.2 degrees C. At the maximum rectal temperature, the heating blankets were removed, and animals were cooled, observed until death occurred or 18 h elapsed, and then sacrificed. The data demonstrate that maximum cooling rates of rectal temperature were: peritoneal lavage, 0.56 degrees C/min; ice slush, 0.11 degrees C/min; and 27 degrees C air cooling, 0.06 degrees C/min. The incidence of 18-h survival for lavage-cooled dogs when supported with normothermic dialysis every 4 h was significantly greater than for either ice slush or air cooled dogs. Anesth Analg. 1996 May;82(5):925-30. Rapid core-to-peripheral tissue heat transfer during cutaneous cooling. Plattner O, Xiong J, Sessler DI, Schmied H, Christensen R, Turakhia M, Dechert M, Clough D. Department of Anesthesia, University of California, San Francisco 94143-0648, USA. Perioperative thermal manipulations are usually directed at the skin surface because methods of directly warming the core are invasive or ineffective. However, inadequate heat flow between peripheral and core compartments will decrease the rate at which core temperature changes. We therefore determined whether core hypothermia is delayed after initiation of surface cooling. Six volunteers were anesthetized with propofol and midazolam, and maintained under three layers of passive insulation for 2.5-4 h. Subsequently, the skin surface was cooled using forced air, 1000 L/min, at 10 degrees C. Isoflurane was added as necessary to maintain arteriovenous shunt vasodilation. Overall heat balance was determined from the difference between cutaneous heat loss (thermal flux transducers) and metabolic heat production (oxygen consumption). Average arm and leg (peripheral) tissue temperatures were determined from 19 intramuscular needle thermocouples, 10 skin temperatures, and "deep" foot temperature. Overall body heat content decreased approximately 234 kcal during 2.5 h of active cooling. Core temperature, which was nearly constant before active cooling, decreased approximately 1.3 degrees C/h. There was no delay between initiation of active cooling and the decrease in core temperature. Furthermore, peripheral (arm and leg) and core (trunk and head) tissue heat contents decreased at virtually the same rates: approximately 50 kcal/h and approximately 47 kcal/h, respectively. These data indicate that there is little restriction of heat flow between peripheral and core tissues in vasodilated, anesthetized subjects. Anesth Analg. 2003 Jun;96(6):1683-7, table of contents. Resistive-heating and forced-air warming are comparably effective. Negishi C, Hasegawa K, Mukai S, Nakagawa F, Ozaki M, Sessler DI. Department of Anesthesia, Tokyo Women's Medical University, Tokyo, Japan. Serious adverse outcomes from perioperative hypothermia are well documented. Consequently, intraoperative warming has become routine. We thus evaluated the efficacy of a novel, nondisposable carbon-fiber resistive-heating system. Twenty-four patients undergoing open abdominal surgery lasting approximately 4 h were randomly assigned to warming with 1) a full-length circulating water mattress set at 42 degrees C, 2) a lower-body forced-air cover with the blower set on high, or 3) a three-extremity carbon-fiber resistive-heating blanket set to 42 degrees C. Patients were anesthetized with a combination of continuous epidural and general anesthesia. All fluids were warmed to 37 degrees C, and ambient temperature was kept near 22 degrees C. Core (tympanic membrane) temperature changes among the groups were compared by using factorial analysis of variance and Scheffe F tests; results are presented as means +/- SD. Potential confounding factors did not differ significantly among the groups. In the first 2 h of surgery, core temperature decreased by 1.9 degrees C +/- 0.5 degrees C in the circulating-water group, 1.0 degrees C +/- 0.6 degrees C in the forced-air group, and 0.8 degrees C +/- 0.2 degrees C in the resistive-heating group. At the end of surgery, the decreases were 2.0 degrees C +/- 0.8 degrees C in the circulating-water group, 0.6 degrees C +/- 1.0 degrees C in the forced-air group, and 0.5 degrees C +/- 0.4 degrees C in the resistive-heating group. Core temperature decreases were significantly greater in the circulating-water group at all times after 150 elapsed minutes; however, temperature changes in the forced-air and resistive-heating groups never differed significantly. Even during major abdominal surgery, resistive heating maintains core temperature as effectively as forced air. IMPLICATIONS: Efficacy was similar for forced-air and resistive heating, and both maintained intraoperative core temperature far better than circulating-water mattresses. We thus conclude that even during major abdominal surgery, resistive heating maintains core temperature as effectively as forced air. Charles Brault EMT-P __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com --- URG-L Pour modifier votre adresse de courriel sur URG-L, envoyez un avis a [EMAIL PROTECTED] en indiquant votre nouvelle adresse ainsi que l'ancienne et le nom de la liste.
