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25/08/2016

Réchauffer une perfusion: La tubulure +++

An Analysis of the Temperature Change in Warmed Intravenous Fluids during Administration in a Cold Environment at Temperatures of Less than 0

2016 Critical Care Transport Medicine Conference Scientific Forum

SIngleton W et Al. Air Medical Journal 35 (2016) 205-207

 

Objective: This is a non-human simulation study determining the decrease in temperature that occurred to 1L bags of Normal Saline in an austere environment. The bags were warmed to 38°C (100°F), administered through standard intravenous tubing at a set flow rate, while in an environment with ambient temperatures of less than 0°C (32°F). The goal was to determine if there was a significant decrease in fluid temperature from the IV bag through the tubing to the IV catheter administration site.

Methods/Materials: Three trials were run at four different temperatures, 0°C (32°F), -7 °C (20°F), -12°C (10°F ) and 33°C (72°F control ). Each bag of normal saline was warmed to the same temperature 38°C (100°F) utilizing the Soft Sack IV Fluid Warmer. Three of the bags were then placed in a cold austere environment (freezer) at each of the specified temperatures. The remaining bag was kept in the ambient temperature 33°C (72°F control). The fluid was administered through standard intravenous tubing (18 gauge catheter, 20 drop set, 211 cm in length) at a flow rate of 999ml/hr in temperatures less than 0°C (32°F). Fluid was collected in a glass container outside the austere environment with the temperature being recorded at 5 minute intervals.

Results: The results demonstrated a statistically significant (p> 0.05) change in temperature between the IV bag and the administration site. The most rapid change occurred within the first 5 minutes. The temperature change was more significant with the colder ambient temperatures, with an average of 50° difference at -7°C (20°F) and -12°C (10°F ). This is compared to a 27° difference at 0°C and the control temperature of 33°C (72°F control). The temperature of the fluid remaining within the IV bag also decreased an average of 15°C at the control temperature of 33°C (72°F control) and 0°C (32°F), which is statistically significant. The temperature in the bag decreased an average of 35°C at -7°C (20°F) and -12°C (10°F), which was statistically significant (p>0.05).

Conclusion: Based on these results, it appears that the most significant heat loss occurs through the IV tubing itself, the loss occurs rapidly, and is more pronounced at colder ambient air temperatures. Therefore, it may be beneficial to insulate the tubing on a trauma patient receiving warmed IV fluids in a cold environment of less than 0°C (32°F) to help prevent hypothermia.

01/05/2015

Gelures

Cold Exposure Injuries to the Extremities

Golant A. et AL. J Am Acad Orthop Surg 2008;16:704- 715

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Un document un peu ancien, mais bien fait notamment une physiopathologie clairement présentée.

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Cold exposure injuries comprise nonfreezing injuries that include chilblain (aka pernio) and trench, or immersion, foot, as well as freezing injuries that affect core body tissues resulting in hypothermia of peripheral tissues, causing frostnip or frostbite. Frostbite, the most serious peripheral injury, results in tissue necrosis from direct cellular damage and indirect damage secondary to vasospasm and arterial thromboses. The risk of frostbite is influenced by host factors, particularly alcohol use and smoking, and environmental factors, including ambient temperature, duration of exposure, altitude, and wind speed. Rewarming for frostbite should not begin until definitive medical care can be provided to avoid repeated freeze-thaw cycles, as these cause additional tissue necrosis. Rewarming should be rapid and for an affected limb should be performed by submersion in warm water at 104° to 107.6°F (40° to 42°C) for 15 to 30 minutes. Débridement of necrotic tissues is generally delayed until there is a clear demarcation from viable tissues, a process that usually takes from 1 to 3 months from the time of initial exposure. Immediate escharotomy and/or fasciotomy is necessary when circulation is compromised. In addition to the acute injury, frostbite is associated with late sequelae that include altered vasomotor function, neuropathies, joint articular cartilage changes, and, in children, growth defects caused by epiphyseal plate damage.

| Tags : gelures

28/02/2015

Hyporthermie: Il faut envelopper !

Protection Against Cold in Prehospital Care: Wet Clothing Removal or Addition of a Vapor Barrier

Henriksson O. et All. Prehosp Disaster Med. 2012 Feb;27(1):53-8

Objective.

The purpose of this study was to evaluate the effect of wet clothing removal or the addition of a vapor barrier in shivering subjects exposed to a cold environment with only limited insulation available.

Methods.

Volunteer subjects (n ¼ 8) wearing wet clothing were positioned on a spineboard in a climatic chamber (–18.51C) and subjected to an initial 20 minutes of cooling followed by 30 minutes of 4 different insulation interventions in a crossover design: 1) 1 woolen blanket; 2) vapor barrier plus 1 woolen blanket; 3) wet clothing removal plus 1 woolen blanket; or 4) 2 woolen blankets. Metabolic rate, core body temperature, skin temperature, and heart rate were continuously monitored, and cold discomfort was evaluated at 5-minute intervals.

Results.

Wet clothing removal or the addition of a vapor barrier significantly reduced metabolic rate (mean difference  SE; 14  4.7 W/m2 ) and increased skin temperature rewarming (1.01  0.21C). Increasing the insulation rendered a similar effect. There were, however, no significant differences in core body temperature or heart rate among any of the conditions. Cold discomfort (median; interquartile range) was significantly lower with the addition of a vapor barrier (4; 2–4.75) and with 2 woolen blankets (3.5; 1.5–4) compared with 1 woolen blanket alone (5; 3.25–6).

VaporBarrier2.jpg

VaporBarrier.jpg

Conclusions. 

In protracted rescue scenarios in cold environments with only limited insulation available, wet clothing removal or the use of a vapor barrier is advocated to limit the need for shivering thermogenesis and improve the patient’s condition on admission to the emergency department

| Tags : hypothermie

16/12/2013

Gelures: Le guidelines de la WMS

Frostbite.jpg

Clic sur l'image pour accéder au document

| Tags : gelures

18/11/2013

Hypothermie et vêtements humides

Dry and wet heat transfert through clothing dependent on the clothing properties under cold conditions

Richards GM et Al. Int J Occup Saf Ergon. 2008;14(1):69-76.

Il est recommandé  lors de la prise en charge de blessés hypothermes de remplacer leurs vêtements humides par de vêtements secs. Ceci permettrait d'éviter l'aggravation de l'hypothermie secondaire à un transfert accru de châleur par conduction et par évaporation. Ceci est loin d'être toujours réalisable. Il convient dès lors de réaliser un isolement particulier du blessé basé sur latechnique de Hibler et dont la couche externe doit être ETANCHE à l'air. Ceci est connu depuis longtemps (ref ici). Le document proposé explique cela.

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Une couche externe ETANCHE réduit les pertes thermiques évaporatives.

Lire la a fiche mémento


| Tags : hypothermie

24/01/2013

Hypothermie et trauma: Un point 2013

Clinical and translational aspects of hypothermia in major trauma patients: From pathophysiology to prevention, prognosis and potential preservation

http://dx.doi.org/10.1016/j.injury.2012.12.027

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Un revue très synthétique à lire, notamment le paragraphe portant sur le recours à une hypothermie induite en cas de traumatisme sévère.

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Generally, hypothermia is defined as a core temperature <35°C. In elective surgery, induced hypothermia has beneficial effects. It is recommended to diminish complications attributable to ischemia reperfusion injury. Experimental studies have shown that hypothermia during hemorrhagic shock has beneficial effects on outcome. In contrast, clinical experience with hypothermia in trauma patients has shown accidental hypothermia to be a cause of posttraumatic complications. The different etiology of hypothermia might be one reason for this disparity because induced therapeutic hypothermia, with induction of poikilothermia and shivering prevention, is quite different from accidental hypothermia, which results in physiological stress. Other studies have shown evidence that this contradictory effect is related to the plasma concentration of high-energy phosphates (e.g., adenosine triphosphate [ATP]). Induced hypothermia preserves ATP storage, whereas accidental hypothermia causes depletion. Hypothermia also has an impact on the immunologic response after trauma and elective surgery by decreasing the inflammatory response. This might have a beneficial effect on outcome. Nevertheless, posttraumatic infectious complications may be higher because of an immunosuppressive profile. Further studies are needed to investigate the impact of induced hypothermia on outcome in trauma patients.

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Quatre plaques pour une lecture rapide

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| Tags : hypothermie

29/12/2012

Hypothermie: Quelle isolation ? Plusieurs couches et étanches à l'air

Protection against cold in prehospital care

Henriksson O. 

Ce travail suédois compare l'efficacité de diverses méthodes d'isolation thermique en fonction des conditions de vent. Le document proposé fait la synthèse de 4 publication par la même équipe:

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Lundgren P, Henriksson O, Widfeldt N, Vikström T. Insulated Spine Boardsfor Prehospital Trauma Care in a Cold Environment. International Journal of Disaster Medicine 2004;2:33–37.

Henriksson O, Lundgren P, Kuklane K, Holmér I, Björnstig U. Protection Against Cold in Prehospital Care – Thermal Insulation Properties of Blankets and Rescue Bags in Different Wind Conditions. Prehosp Disaster Med. 2009;24(5):408–415.

Henriksson O, Lundgren P, Kuklane K, Holmér I, Naredi P, Bjornstig U. Protection Against Cold in Prehospital Care: Evaporative Heat Loss Reduction by Wet Clothing Removal or the Addition of a Vapor Barrier – A Thermal Manikin Study. Prehosp Disaster Med 2012;26(6):1–6. 2009;24(5):408–415

Henriksson O, Lundgren P, Kuklane K, Holmér I, Giesbrecht G, Naredi P, Björnstig U. Protection Against Cold in Prehospital Care – The Effect on Thermoregulation by Wet Clothing Removal or Addition of a Vapour Barrier in Shivering Subjects. Manuscript.

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On utilise souvent une couverure aluminisée comme moyen deprévention de l'hypothermie? Cette façon de faire est peu efficace et doit être remise en questoin surtout en présence de vent, ce qui est habituel lors d'EVASAN Hélico. Il est alors fondamental d'avoir recours à des protections étanches non compressibles par le vent ambiant. Le retrait des vêtemenst humides n'apparaît pas être nécessaire si ces conditions sont obtenues.

hypothermie

hypothermie

hypothermie.jpg

 

| Tags : hypothermie

02/12/2012

La thermorégulation par N. Deye IAR IDF

iar.JPG

Clic sur le logo pour accéder au cours

28/11/2012

Hypothermie: Toujours une réalité!

Evaluation of military trauma system practices related to damage-control resuscitation

Palm K et All. J Trauma Acute Care Surg. 2012;73: S459YS464.

 

Hypothermia 5.JPG

Patients admitted with documented temperature less than 96.8-F (36-C) January 2002 to December 2011 Operation Enduring Freedom and Operation Iraqi Freedom/Operation New Dawn combined.

La prévention d'une hypothermie est un des enjeux de la prise en charge du combattant blessé. Dans ce texte les auteurs rapportent l'évolution de la température à la prise en charge hospitalière sur une période de plus de 10 ans. Malgré l'introduction en 2006 d'une procédure de mise en place en 2006 d'une procédure spécifique,  On note la réapparition de ce problème en 2010 notamment sur le théâtre afghan (contexte climatique, moindre adéquation à la procédure ??). 

On rappelle l'importance de la qualité de la mise en oeuvre des moyens disponibles dont le principe global est l'isolation la plus parfaite possible du blessé aux effets de l'environnement (froid, vent, humidité) notamment par la technique de l'oignon (technique de hibbler). La mise en oeuvr d'une protection thermique nécessite donc un entraînement spécifique.

La fiche mémento sur l'hypothermie est accessible ici



 


 

 


14/07/2012

Secours en milieu froid

 http://www.cosafe.eu/PDF/ENG_booklet_casualty_workers%20(... 

Un document intéressant qui fait le point sur les principes de la mise en condition des blessés en milieu froid

Réchauffer les perfusions

An experimental study of warming intravenous fluid in a cold environment.

Platts-Mills TF et all. Wilderness Environ Med. 2007 Fall;18(3):177-85.

Il existe des moyens artisanaux pour réchauffer les perfusions, notamment l'emploi de pack de réchauffe de rations alimentaires.

Cette manière de faire n'est pas toujours efficace et dans certains cas réchauffe de manière trop importante les solutés qui dépasse alors la température maximum généralement admise à laquelle ces derniers peuvent être perfusés: 42°c

 

RechauffPErf.JPG

Il peut être proposé d'attendre une dizaine de minutes avant de'adminstrer ces perfusions. 

Réchauffement Perf.JPGhttp://www.fresno.ucsf.edu/em/posters/2006_IVF_warming.pdf

Bien sur il existe des dispositifs électriques mais aussi des packs chimiques spécifiques

5 1Panel with IV.jpg

17/06/2012

Prise en charge d’un blessé en hypothermie accidentelle

Prise en charge d’un malade en hypothermie accidentelle

Briot R et all. Réanimation (2010) 19, 607—615

 

ATTENTION le réchauffement préhospitalier a pour objectif de limiter l'hypothermie.

ATTENTION un réchauffement actif préhospitalier n'est pas indiqué si l'hypothermie est profonde

ATTENTION le réchauffement actif préhospitalier est d'autant plus efficace si la conscience et le frisson persistent

 

Hypothermie sans frissons.jpg

ici la procédure du SAMU 38

05/05/2012

Ready heat ou triple couche ?

The effect of active warming in prehospital trauma care during road and air ambulance transportation - a clinical randomized trial.

Lundgren P. et all  Scand J Trauma Resusc Emerg Med. 2011 Oct 21;19:59.

La prévention de l'hypothermie fait appel à des moyens de réchauffement cutanés passifs ( couverture renforcée type Rothco ou la couverture triple couche type blizzard blanket ) ou actifs (couverture ready-heat). Mais comment choisir ?

Le travail présenté ici démontre qu'en présence d'une hypothermie modérée supérieures à 35°C il n'est pas utile d'avoir recours à un moyen actif en terme de limitation de l'hypothermie dès lors que le frisson est conservé. Le seul gain porte sur un confort thermique accru.

hypothermia 4.JPG

BACKGROUND:

Prevention and treatment of hypothermia by active warming in prehospital trauma care is recommended but scientific evidence of its effectiveness in a clinical setting is scarce. The objective of this study was to evaluate the effect of additional active warming during road or air ambulance transportation of trauma patients.

METHODS:

Patients were assigned to either passive warming with blankets or passive warming with blankets with the addition of an active warming intervention using a large chemical heat pad applied to the upper torso. Ear canal temperature, subjective sensation of cold discomfort and vital signs were monitored.

RESULTS:

Mean core temperatures increased from 35.1°C (95% CI; 34.7-35.5°C) to 36.0°C (95% CI; 35.7-36.3°C) (p < 0.05) in patients assigned to passive warming only (n = 22) and from 35.6°C (95% CI; 35.2-36.0°C) to 36.4°C (95% CI; 36.1-36.7°C) (p < 0.05) in patients assigned to additional active warming (n = 26) with no significant differences between the groups. Cold discomfort decreased in 2/3 of patients assigned to passive warming only and in all patients assigned to additional active warming, the difference in cold discomfort change being statistically significant (p < 0.05). Patients assigned to additional active warming also presented a statistically significant decrease in heart rate and respiratory frequency (p < 0.05).

CONCLUSIONS:

In mildly hypothermic trauma patients, with preserved shivering capacity, adequate passive warming is an effective treatment to establish a slow rewarming rate and to reduce cold discomfort during prehospital transportation. However, the addition of active warming using a chemical heat pad applied to the torso will significantly improve thermal comfort even further and might also reduce the cold induced stress response.

| Tags : hypothermie

11/04/2012

Prise en charge des victimes d'avalanche ?

ICAR MEDCOM guidelines 2002

Il s'agit des recommandations de l'International Commission for Alpine Emergency Medicine

http://users.south-tyrolean.net/avalanche/pdf/Guidelines_...

Accidental Hypothermia

Accidental Hypothermia

Davis PR et all. J R Army Med Corps 2006; 152: 223-233

 

Une revue générale sur la prise en charge des hypothermies accidentelles. Il y en a d'autres mais son intérêt est d'être rédigée par nos collègues anglais

http://www.ramcjournal.com/2005/hostile_environments/davi...

12/02/2012

hypothermie: Isoler le blessé du brancard !

Les phénomènes de conduction ne doivent pas être négligés dans la génèse de l'hypothermie.

 

hypothermie

C'est ce que rappelle la publication suivante:


Assessment of Hypothermia Blankets Using an Advanced Thermal Manikin. 

Rugh JP et All. Conference Paper NREL/CP-540-45888 July 2009

http://www.nrel.gov/vehiclesandfuels/ancillary_loads/pdfs...

hypothermia 3.JPG

| Tags : hypothermie

Hypothermie et couverture chimiques

Assessment of Hypothermia Blankets Using an Advanced Thermal Manikin. 

Rugh JP et All. Conference Paper NREL/CP-540-45888 July 2009

http://www.nrel.gov/vehiclesandfuels/ancillary_loads/pdfs...

 

Elles sont efficaces. Elles ne doivent JAMAIS être placées au contact direct de la peau. 

hypothermia 1.JPG

hypothermia 2.JPG

 

 

| Tags : hypothermie

05/02/2012

Hypothermie et la méthode de Hibbler

HYpothermie_Comparaison couvertures.JPG

 

 Hypothermie_hibbler.JPG

 

 

 

 

La méthode de hibbler est une méthode de prévention relativement simple faisant appel à la superposition d'au moins deux couvertures réflective +/- une source de chaleur. Le blessé doit être parfaitement emmailloté sans fuite d'air.

 

Il existe peu de littérature concernant la véritable efficacité des divers moyens employés. Le travail présenté par Thomassen et ses associés rappelle que des moyens simples sont aussi efficace que l'emploi de couvertures standards oude bubble Wrapp.

 

La fiche mémento sur l'hypothermie est accessible ici

23/01/2012

Prise en charge des gelures

http://www.ramcjournal.com/2011/mar11/grieve.pdf

10/12/2011

Military Mountaineering

http://ps-survival.com/PS/Military_FMs/FM_3-97_61c1_Milit...