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21/09/2016

Hypothermie accidentelle: Vision scandinave

Accidental hypothermia-an update : The content of this review is endorsed by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM).

Paal et al. Scand J Trauma Resusc Emerg Med. (2016) 24:111

 

BACKGROUND:

This paper provides an up-to-date review of the management and outcome of accidental hypothermia patients with and without cardiac arrest.

METHODS:

The authors reviewed the relevant literature in their specialist field. Summaries were merged, discussed and approved to produce this narrative review.

RESULTS:

The hospital use of minimally-invasive rewarming for non-arrested, otherwise healthy, patients with primary hypothermia and stable vital signs has the potential to substantially decrease morbidity and mortality for these patients. Extracorporeal life support (ECLS) has revolutionised the management of hypothermic cardiac arrest, with survival rates approaching 100 % in some cases. Hypothermic patients with risk factors for imminent cardiac arrest (temperature <28 °C, ventricular arrhythmia, systolic blood pressure <90 mmHg), and those who have already arrested, should be transferred directly to an ECLS-centre. Cardiac arrest patients should receive continuous cardiopulmonary resuscitation (CPR) during transfer. If prolonged transport is required or terrain is difficult, mechanical CPR can be helpful. Delayed or intermittent CPR may be appropriate in hypothermic arrest when continuous CPR is impossible. Modern post-resuscitation care should be implemented following hypothermic arrest. Structured protocols should be in place to optimise pre-hospital triage, transport and treatment as well as in-hospital management, including detailed criteria and protocols for the use of ECLS and post-resuscitation care.

CONCLUSIONS:

Based on new evidence, additional clinical experience and clearer management guidelines and documentation, the treatment ofaccidental hypothermia has been refined. ECLS has substantially improved survival and is the treatment of choice in the patient with unstable circulation or cardiac arrest.

 

| Tags : hypothermie

01/09/2016

Chaud et froid: Nous aussi !

Critical care at extremes of temperature: effects on patients, staff and equipment

Hindle EM, et al. J R Army Med Corps 2014;160:279–285

 

Le chaud et le froid ont aussi des effets sur notre performance, et il faut en tenir compte.

 

Modern travel and military operations have led to a significant increase in the need to provide medical care in extreme climates. Presently, there are few data on what happens to the doctor, their drugs and equipment when exposed to these extremes. A review was undertaken to find out the effects of ‘extreme heat or cold’ on anaesthesia and critical care; in addition, subject matter experts were contacted directly. Both extreme heat and extreme cold can cause a marked physiological response in a critically ill patient and the doctor treating these patients may also suffer a decrement in both physical and mental functioning. Equipment can malfunction when exposed to extremes of temperature and should ideally be stored and operated in a climatically controlled environment. Many drugs have a narrow range of temperatures in which they remain useable though some have been shown to remain effective if exposed to extremes of temperature for a short period of time. All personnel embarking on an expedition to an extreme temperature zone should be of sufficient physical robustness and ideally should have a period of acclimatisation which may help mitigate against some of the physiological effects of exposure to extreme heat or extreme cold. Expedition planners should aim to provide climatic control for drugs and equipment and should have logistical plans for replenishment of drugs and medical evacuation of casualties.

24/09/2015

Coup de chaleur: Position US

 

 

Heat.jpg

 

Le coup de chaleur d'exercice est une réalité. Un refroidissement obtenu en moins de 30 minutes est indispensable. L'immersion corps entier est la méthode la plus efficace mais n'est pas forcément disponible. Le refroidissement par immersion des membres supérieurs est discuté. Une approche très intéressante semble être l'emploi de nouvelles couvertures refroidissantes (lien) qui permettent un abaissement significatif des mesures de refroississement dès le lieu de prise en charge et pendant toute la phase de transport.

| Tags : hyperthermie

15/08/2015

Hypoxie d'altitude: Pour les AMET AUSSI !

Effects of Altitude-Related Hypoxia on Aircrews in Aircraft With Unpressurized Cabins

Nishi S. Military Medicine, 176, 1:79, 2011

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La prise en charge de blessés en altitude ajoute à l'hémorragie le problème de l'hypoxie liée à la baisse de la PAO2 par baisse de la pression barométrique. Ceci joue aussi pour les sauveteurs, dès 1500 m,  dont la performance peut être moindre avec une réduction de la capcité de concentration et une baisse d'acuité visuelle marquée à partir de 3000 m. Cela peut être le cas des équipes AMET dès lors que les cabines ne sont pas pressurisées

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Introduction: Generally, hypoxia at less than 10,000 ft (3,048 m) has no apparent effect on aircrews. Nevertheless, several hypoxic incidents have been reported in flights below 10,000 ft. A recently introduced pulse oximeter using finger probes allows accurate monitoring of oxygen saturation (SPO 2 ) in the aeromedical environment. Using such a pulse oximeter, inflight SPO 2 levels were evaluated in aircrew in unpressurized aircraft. In addition, career in- flight hypoxic experiences were surveyed.

Methods: In-fl ight SPO 2 was measured in aircrews operating UH-60J helicopters at up to 13,000 ft, and 338 aircrew members operating unpressurized cabin aircraft were surveyed concerning possible in-fl ight hypoxic experiences.

Results: In aircrews operating UH-60J helicopters, SPO 2 decreased significantly at altitudes over 5,000 ft, most markedly at 13,000 ft (vs. ground level). The survey identified three aircrew members with experiences suggesting hypoxemia at below 5,000 ft.

Conclusions: Careful attention should be paid to the possibility of hypoxia in aircrews operating unpressurized cabin aircraft. 

| Tags : altitude

26/07/2015

Gestion des contraintes thermiques

Management of Heat and Cold Stress – Guidance to NATO Medical Personnel

Findings of Task Group HFM-187

Work-to-Rest-WBGT.png

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Egalement:  Consensus recommendations on training and competing in the heat

22/07/2015

Hyperthermie d'effort: Quoi de neuf ?

Exertional Heat Stroke: New Concepts Regarding Cause and Care

Casa DJ  et All. Curr Sports Med Rep. 2012 May-Jun;11(3):115-23

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Une bibliographie très riche pour ce qui est pour nous une préoccupation régulière. Lire aussi (1, 2,3)

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When athletes, warfighters, and laborers perform intense exercise in the heat, the risk of exertional heat stroke (EHS) is ever present. The recent data regarding the fatalities due to EHS within the confines of organized American sport are not promising: during the past 35 years, the highest number of deaths in a 5-year period occurred from 2005 to 2009. This reminds us that, regardless of the advancements of knowledge in the area of EHS prevention, recognition, and treatment, knowledge has not been translated into practice. This article addresses important issues related to EHS cause and care. We focus on the predisposing factors, errors in care, physiology of cold water immersion, and return-to-play or duty considerations

| Tags : hyperthermie

28/06/2015

Froid: Alaska Guide 2014

ColdInjuriesAlaska Guidelines.jpg

Clic sur l'image pour accéder au document

| Tags : hypothermie

27/06/2015

Médecine d'altitude: Manuel sponsorisé par l'OTAN

HighAltitude.jpg

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| Tags : altitude

22/06/2015

OHB des gelures: Etudes des pratiques européennes ?

Place de l'oxygenotherapie hyperbare dans le traitement des gelures : Evaluations des pratiques europeennes

Thèse de médecine Kolakowska E.

À l’heure actuelle, l’oxygénothérapie hyperbare (OHB) ne fait pas partie des recommandations pour le traitement des gelures et pourtant elle est proposée par plusieurs spécialistes. La gelure est une lésion tissulaire survenant lors d’une exposition prolongée et directe à une température inférieure à 0 °C. L’OHB pourrait être utile par le biais de l’amélioration de l’oxygénation locale, la limitation de l’oedème, la lutte contre l’infection et la stimulation des processus de cicatrisation. L’équipe du centre hyperbare de l’Hôpital de Sainte-Marguerite à Marseille avait traité les victimes de gelures avec des résultats très encourageants, ce qui nous a motivé à évaluer les pratiques concernant l’utilisation de l’OHB dans la prise en charge des gelures dans différents centres hyperbares Européens et vérifier, s’il avait existé un bénéfice thérapeutique. Il s’agit d’une étude réalisée à l’aide d’un questionnaire auprès des médecins exerçant aux caissons hyperbares en Europe. Sur 134 messages envoyés, 21 médecins avaient rempli le questionnaire. 86 % des spécialistes estimaient que théoriquement l’OHB pourrait être indiquée dans la prise en charge de gelures. Parmi les 25 patients inclus, 84 % avaient été atteints de gelures profondes et seulement 44% avaient bénéficié d’une prise en charge dans les premières 72 heures. Malgré la gravité des lésions et le délai de la prise en charge, nous avons constaté, qu’à 3 mois d’évolution, 88 % des patients avaient présenté une amélioration sur le plan cutané par rapport à l’état initial. Bien que notre étude ne soit pas d’une grande valeur statistique, elle permet toutefois de s’apercevoir du bénéfice thérapeutique que l’OHB pourrait apporter dans cette pathologie, y compris tardivement. En effet, des études prospectives larges seront nécessaires et justifiées.

Rappel: Schéma physiopathologique de la gelure 

Gelure Physiopath.jpg

| Tags : gelures

21/05/2015

Médecine de haute altitude: En pratique, c'est quoi ?

Mount Everest Base Camp Medical Clinic “Everest ER”: Epidemiology of Medical Events During the First 10 Years of Operation

Pressman BA et AL. Wilderness Environ Med. 2015 Mar;26(1):4-10

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Si l'intervention dans de telles conditions nécessite évidemment une pratique réelle de la montagne en haute altitude, la spécificité de la pathologie médicale rencontrée semble être essentiellement en rapport avec l'isolement.

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Objective:

As the highest peak on the planet, Mount Everest provides a truly austere environment in which to practice medicine. We examined records of all visits to the Everest Base Camp Medical Clinic (Everest ER) to characterize the medical problems that occur in these patients.

Methods:

A retrospective analysis of medical records from the first 10 years of operation (2003–2012) was performed. Descriptive data collected included patient demographics, diagnoses, treatments, prescriptions, medications dispensed, and evacuation type, if any.

Results: In all, 2941 patients were seen for a total of 3569 diagnoses. The number of patient visits each year at the Everest ER increased at a greater rate than the total numbers of climbers attempting Mount Everest over this period. The most commonly treated patients were Nepalese, accounting for 51% of all nationalities. The most common medical diagnoses were from pulmonary causes such as high altitude cough and upper respiratory infections, comprising more than 38% of all medical diagnoses. The most common traumatic diagnoses were from dermatologic causes such as frostbite and lacerations, comprising 56% of all traumatic diagnoses. Pulmonary and dermatologic diagnoses were also the most frequent reasons for evacuation from Everest Base Camp, most commonly for high altitude pulmonary edema and frostbite, respectively.

Conclusions:

Medical professionals treating patients at extreme altitude should have a broad scope of practice and should be well prepared to deal with serious traumas from falls, cold exposure injuries, and altitude illness.

| Tags : altitude

29/03/2015

O2 pas mieux extrait lors de l'effort en altitude !

Systemic oxygen extraction during exercise at high altitude

Martin DS et Al. British Journal of Anaesthesia 114 (4): 677–82 (2015)

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On pourrait penser que qu'un des mécanismes d'adaptation à l'effort conduit en haute altitude soit l'augmentation de l'extraction d'oxygène, il semble qu'il n'en soit rien. C'est ce que suggère le travail proposé qui avance par ailleurs que ceci serait en relation avec:

1. Une anomalie de diffusion tissulaire de l'oxygène notamment à cause de la baisse du gradient de pression partielle entre capillaire et mitochondrie, ceci étant associé à la réduction du temps de transit capillaire musculaire  en rapport avec l 'effort.

2. Des anomalies régionales de besoins en oxygène avec hétérogénéité des débits sanguins régionaux.

3. La redistribution des débits sanguins musculaires vers les organes dits "nobles"

4. La réduction de la consommation au niveau mitochondrial

En altitude la consommation en oxygène est plus en rapport avec la consommation mitochondriale qu'avec la délivrance d'oxygène aux tissus. 

Ces observations vont l 'opposé de ce que l'on peut observer en cas d'hémorragie. On peut se poser la question des mécanismes d'adaptations en cas d'hémorragie survenant dans les mêmes conditions. EN tous cas ne changeons rien, continuons d'en apporter.

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Background.

Classic teaching suggests that diminished availability of oxygen leads to increased tissue oxygen extraction yet evidence to support this notion in the context of hypoxaemia, as opposed to anaemia or cardiac failure, is limited.

Methods.

At 75 m above sea level, and after 7–8 days of acclimatization to 4559 m, systemic oxygen extraction [C(a2v)O2] was calculated in five participants at rest and at peak exercise. Absolute [C(a2v)O2] was calculated by subtracting central venous oxygen content (CcvO2) from arterial oxygen content (CaO2 ) in blood sampled from central venous and peripheral arterial catheters, respectively. Oxygen uptake (VO˙ 2) was determined from expired gas analysis during exercise.

Results.

Ascent to altitude resulted in significant hypoxaemia; median (range) SpO2 87.1 (82.5–90.7)% and PaO2 6.6 (5.7–6.8) kPa. While absolute C(a-v)O2 was reduced at maximum exercise at 4559 m [83.9 (67.5–120.9) ml litre-1 vs 99.6 (88.0–151.3) ml litre-1 at 75 m, P¼0.043], there was no change in oxygen extraction ratio (OER) [C(a-v)O2/CaO2] between the two altitudes [0.52 (0.48–0.71) at 4559 m and 0.53 (0.49–0.73) at 75 m, P¼0.500]. Comparison of C(a-v)O2 at peak VO˙ 2 at 4559 m and the equivalent VO˙ 2 at sea level for each participant also revealed no significant difference [83.9 (67.5–120.9) ml litre1 vs 81.2 (73.0–120.7) ml litre-1 , respectively, P¼0.225].

Conclusion.

In acclimatized individuals at 4559 m, there was a decline in maximum absolute C(a-v)O2 during exercise but no alteration in OER calculated using central venous oxygen measurements. This suggests that oxygen extraction may have become limited after exposure to 7–8 days of hypoxaemia.

20/01/2015

Obstétrique à l'hôpital de district

Un document ancien, mais qui peut vous sortir de ennuis si vous vous trouver "seul au monde" face à une urgence obstétricale

cesarean.jpg

Clic sur l'image pour accéder au document

18/01/2015

Lesions dues au froid: Pas que les gelures

 NonFreezing.jpg

Clic sur l'image pour accéder au document

| Tags : gelures

25/11/2014

Environnement extrême: Les reco du CIO

International Olympic Committee consensus statement on thermoregulatory and altitude challenges for high-level athletes

Bergeron MF et AL. Br J Sports Med. 2012 Sep;46(11):770-9

Logo of epm

Clic sur l'image pour accéder au document

 

Dermatologie d'altitude: La connnaître

Incidence and Care of Environmental Dermatoses in the High-Altitude Region of Ladakh, India

Singh GK et All. Indian J Dermatol. 2013 Mar-Apr; 58(2): 107–112.

BACKGROUND:

Low humidity, high-velocity wind, excessive ultraviolet (UV) exposure, and extreme cold temperature are the main causes of various types of environmental dermatoses in high altitudes.

MATERIALS AND METHODS:

A retrospective study was carried out in patients visiting the lone dermatology department in Ladakh between July 2009 and June 2010. The aim was to identify the common environmental dermatoses in high altitudes so that they can be treated easily or prevented. The patients were divided into three demographic groups, namely, lowlanders, Ladakhis (native highlanders), and tourists. Data was analyzed in a tabulated fashion.

RESULTS:

A total of 1,567 patients with skin ailments were seen, of whom 965 were lowlanders, 512 native Ladakhis, and 90 were tourists. The skin disorders due to UV rays, dry skin, and papular urticaria were common among all groups. The frequency of melasma (n = 42; 49.4%), chronic actinic dermatitis (CAD) (n = 18; 81.81% of total CAD cases), and actinic cheilitis (n = 3; 100%) was much higher among the native Ladakhis. The frequency of cold-related injuries was much lesser among Ladakhis (n = 1; 1.19%) than lowlanders (n = 70; 83.33%) and tourists (n = 13; 15.47%) (P < 0.05).

CONCLUSION:

Dryness of skin, tanning, acute or chronic sunburn, polymorphic light reaction, CAD, insect bite reactions, chilblain, and frostbite are common environmental dermatoses of high altitudes. Avoidance of frequent application of soap, application of adequate and suitable emollient, use of effective sunscreen, and wearing of protective clothing are important guidelines for skin care in this region.

| Tags : altitude

12/11/2014

Prevention and Treatment of Acute Altitude Illness

Wilderness Medical Society Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness

Luks AM et All. Wilderness Environ Med. 2010 Jun;21(2):146-55

To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the prevention and treatment of acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations for their roles in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to the prevention and management of each disorder that incorporate these recommendations.

| Tags : altitude

Hypothermie accidentelle: Guidelines 2014 de la WMS

Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia

Zaphren K. et All. Wilderness Environ Med. 2014 in press

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Doit être remarqué la recommandation de ne pas mobiliser le blessé hypotherme pendant au moins 30 min après la mise en oeuvre des techniques de réchauffement. Ceci a pour objet de limiter les effets de l'afterdrop, mécanisme par lequel le réchauffement peut transitoirement aggraver l'hypothermie centrale par un mécanisme de recirculation de sang froid. 

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1. The key factors to guide treatment are level of consciousness, shivering intensity, and cardiovascular stability, based on blood pressure and cardiac rhythm  Core temperature can provide additional helpful information (panel consensus).

2. A patient who is shivering but able to function well and to care for himself or herself is unlikely to be hypothermic. A patient who is shivering, becoming incapacitated, and having difficulty caring for himself or herself is likely to be hypothermic. If there is any doubt, assume that the patient is hypothermic (panel consensus).

3. Because the temperature ranges to which the HT grades are meant to correspond are the same as the standard classification, rescuers should refer to mild, moderate, severe, and profound hypothermia (<24°C) on the basis of their clinical observations, remembering that shivering can occur below 32°C, usually with altered mental status, and that patients can have detectable vital signs with core temperatures below 24°C (panel consensus).

4. Clinicians should consider causes other than hypothermia to explain altered mental status or lack of shivering that does not correlate with the measured core temperature or by a history of minimal cold exposure (panel consensus).

5. In a patient whose airway has been secured with an endotracheal tube or with a supraglottic airway that has a port for placing a gastric tube, use esophageal temperature monitoring with the esophageal temperature probe inserted into the lower third of the esophagus (1C).

6. Use an epitympanic thermometer designed for field conditions with an isolating ear cap in a patient whose airway has not been secured by endotracheal intubation or a supraglottic airway or in a patient with a secured airway if an esophageal probe is not available (1C)

7. Rectal temperature should not be measured in the field until the patient is in a warm environment (1C).

8.Use oral temperature measurement with a thermometer (electronic or liquid-filled) that can read below 35°C only to rule out hypothermia (1A).

9. Monitor rectal or bladder temperature during rewarming of an unconscious patient only if an esophageal or epitympanic probe is not available. If rectal or bladder temperature is used for monitoring during rewarming, allow for inaccuracy owing to the time lag behind core temperature changes (1A).

10. Do not use a temporal artery thermometer in a possibly hypothermic patient (1C)

11. The decision to rescue or to resuscitate a potentially severely hypothermic patient should only be made after the scene is secure and safe for the rescuers to enter and make an evaluation (1A). After safety of rescuers has been assured, the priorities in out-of-hospital treatment of a hypothermic patient who is not in cardiac arrest are to avoid causing cardiovascular collapse during rescue, to prevent a further decrease in core temperature (afterdrop), and to rewarm the patient in a safe manner. If a hypothermic patient is in cardiac arrest, rescuers should initiate resuscitation, if indicated.

12. Rescuers should keep a hypothermic patient horizontal, especially during rescue from water or from a crevasse (1B) and should limit physical effort by the patient during rescue (1B). A conscious patient should be encouraged to be vigilant and focus on survival (1C).

13. Handle a hypothermic patient gently and continue to keep the patient horizontal (1B). Avoid any disturbance, especially movement of the extremities that might precipitate VF (1B). Once the patient is in a warm environment, clothes should be cut off rather than removed manually (1B)

14. Protect from further cooling by using insulation and a vapor barrier until the patient has reached a warm environment, such as the interior of an ambulance. Remove wet clothes, preferably by cutting them off, only when the patient has been protected from the cold (1C). Take special care to insulate the patient from the ground (eg, with sleeping pads) to protect from conductive heat loss and also to protect the head and neck by closing the area around the face as effectively as possible (1C).

15. Use an outer windproof layer to protect the patient from wind and especially from rotor wash when loading or unloading from a helicopter (1C).

16. Shivering is an effective method of rewarming a patient who is cold but not hypothermic or who is mildly hypothermic. The patient must have sufficient energy reserves to sustain shivering and must be adequately insulated from the environment to retain the heat that is generated (1A)

17. An alert patient who is shivering, and who is not at risk for aspiration, should receive high-carbohydrate liquids and food. Liquids and food may be warmed but should not be hot enough to cause burns (1C).

18. Initially, a hypothermic patient should not be allowed to stand or walk (1C)

19. A shivering patient who may be hypothermic should be kept as warm as possible, given calorie replacement, and observed for at least 30 minutes before exercising. The patient should be monitored closely. An alert patient may be allowed to stand. If the patient can stand without difficulty, exercise intensity should start low and increase gradually as tolerated (1C)

20. Large heat pads should be used, if available (1B). Rewarming devices should be used in conjunction with vapor barriers and insulation (1C). The HeatPac should only be used outdoors or with proper ventilation that is carefully monitored (1B).

21. Body-to-body rewarming can be used in mild hypothermia to increase patient thermal comfort if enough personnel are available and if it does not delay evacuation to definitive care (1B).

22. Apply heat sources to the axillae, chest, and back. A large heat pad or blanket should be placed over the chest and, if large enough, extended into the axillae and under the back (1B). Additional heat, if available, can be applied to the neck if precautions are taken to prevent heat loss through any neck opening (1C). Avoid applying external heat to the extremities, although it is not necessary to insulate the arms from heat applied to the torso (1B).

23. The HPMK can be used as a convenient and effective means of preventing heat loss and providing active external rewarming (1C).

24. Avoid localized pressure to cold skin. Heat should never be applied directly to the skin. A barrier should be used to prevent burning the skin when using chemical or electrical heat pads or warm water bottles (1C).

25. Do not use small chemical heat packs for rewarming a hypothermic patient (1B). Small chemical heat packs can be used to prevent local cold injury to the hands and feet during treatment and transport (1C).

26. Heated humidified oxygen can be used in combination with other rewarming methods (2C), but should not be relied on as the only rewarming method (1B).

27. Do not use a warm shower or bath for rewarming, even if a patient appears to be only mildly hypothermic (1C).

28. Distal limb warming to the elbows and knees in 421C to 451C water can be used for rewarming a patient with mild hypothermia (1C).

29. Forced-air warming should be used during air or ground transport, if available (1A). If forced-air warming is not available, use of heat pads, including the HPMK, can be continued. Care must be take to prevent CO buildup with the charcoal HeatPac in a ground ambulance; this can be done by igniting the device outside the vehicle, bringing it inside only after initial smoke production subsides, ventilating the vehicle compartment, and monitoring CO (1C). HeatPac should not be used in an aircraft (1C).

30. Patient compartments in ground and air ambulances should be heated to at least 241C, if possible, to decrease further heat loss (1C).

31. A cold-stressed patient who is not hypothermic does not need to be kept horizontal. The patient may be allowed to remove his or her own wet clothing and to put on dry clothing without shelter, if necessary. The patient may be allowed to rest in a sitting position, to eat and drink to maintain energy reserves and hydration, and may move or keep moving, if necessary (panel consensus).

32. Fixed, dilated pupils, apparent rigor mortis, and dependent lividity are not contraindications to resuscitation of a severely hypothermic patient (1A for fixed, dilated pupils and apparent rigor mortis; 2C for dependent lividity). If there are no contraindications to cardiopulmonary resuscitation (CPR), rescuers should not give up hope and should attempt resuscitation (1A).

33. Do not attempt to resuscitate a patient with obvious fatal injuries or whose chest wall is too stiff for compressions (1A).

34. Do not attempt resuscitation in an avalanche victim buried for 35 minutes or longer with an airway that is definitely obstructed by snow or ice (1A).

35. Rescuers should make every effort to move the patient to a warm setting, such as a ground or air ambulance or a medical facility where cardiac monitoring is available to guide resuscitation and to start rewarming (1C). Before starting CPR, feel for a carotid pulse for 1 minute. If there is no detectible pulse after 1 minute, start CPR, including rescue breathing (1C).

36. CPR should be started if a nonperfusing rhythm, including ventricular tachycardia (VT), VF, or asystole, is detected. If there is a cardiac rhythm with organized QRS complexes (other than VT), CPR should not be performed (1C) unless ETCO2 monitoring confirms lack of perfusion or echocardiography shows that there are no cardiac contractions corresponding to electrical activity (1B).

37. If shock is advised by the AED, attempt defibrillation and start CPR. If no shock is advised on an AED, no carotid pulse is found after palpating for at least 1 minute, normal breathing or other signs of life are not observed, and ultrasound is not available to verify cardiac activity or pulses, start CPR (1C).

38. In patients with severe or profound hypothermia, CPR can be delayed (“scoop and run”) and can be given intermittently during evacuation if it is not technically possible or safe to perform continuous CPR (1C). CPR can be given for several hours, if necessary (1B).

39. If there is no contraindication to CPR and no indication to terminate CPR, continue resuscitation attempts in a patient even if the core temperature is below 101C measured by an esophageal probe in the lower third of the esophagus (2C).

40. If a cardiac monitor is available, use maximal amplification to search for QRS complexes (1C).

41. If a monitor or defibrillator shows VT or VF or if shock is advised by an AED in a patient whose core temperature is thought to be below 301C, give a single shock at maximal power (1C).

42. Wait until a patient has been rewarmed at least 11C to 21C or to 301C before attempting further shocks (2C). Once the core temperature reaches 301C, follow defibrillation guidelines for normothermic patients (1C).

43. For cardiac arrest in a hypothermic patient, deliver chest compressions at the same rate as in normothermic patients (1C).

44. In the absence of ETCO2 monitoring, deliver ventilations at the same rate recommended for a normothermic patient,11,17 unless an advanced airway is in place (see below) (2C).

45. gement. Recommendation. In a patient with an advanced airway, if ETCO2 monitoring is not available, deliver ventilations at half the rate recommended for a normothermic patient to avoid hyperventilation (1C).

46. If ETCO2 monitoring is available, keep ETCO2 within the normal range. In rescues at altitudes above 1200 m, ALS personnel should be aware of the normal range of ETCO2 at a given altitude (1C).

47. High-quality CPR can be performed effectively during prolonged transport using a mechanical device (1C).

48. The advantages of advanced airway management outweigh the risk of causing VF (1C). A nasogastric or orogastric tube should also be placed to decompress the stomach, after the airway is secured (1C).

49. Below a core temperature of 301C, dosages of anesthetic and neuromuscular blocking agents should be lowered and intervals extended according to the degree of hypothermia. Current data are insufficient to recommend specific protocols (1C).

50. A hypothermic patient may receive supplemental oxygen, especially at altitudes greater than 2500 m. There is potential benefit and no known harm (1C).

51. If circulatory access cannot immediately be obtained with a peripheral IV catheter, access should be obtained by the IO method (1C). Central venous access can be obtained using a femoral line if no other option is available (1C).

52. Resuscitate a hypothermic patient with normal saline warmed to 401C to 421C given IV or IO. Use caution to prevent volume overload (1B).

53. When practical, fluids should be given as boluses rather than by continuous infusion (1C). The goal of fluid administration should be to maintain systolic blood pressure at a level that provides adequate perfusion, depending on the degree of hypothermia (1C).

54. Glucose should be administered to a hypothermic patient who is hypoglycemic (1A). Insulin is not initially indicated for hyperglycemia (1B). If glucose testing is not available, IV glucose can be administered empirically to a hypothermic patient with altered mental status (1C).

55. Transcutaneous pacing may be beneficial in hypothermia in the setting of bradycardia with hypotension disproportionate to the core temperature (2C).

56. No treatment is indicated for atrial dysrhythmias in a hemodynamically stable patient during rewarming (IB).

57. A severely injured patient should be treated early and aggressively with active rewarming during all phases of out-of-hospital care to prevent hypothermia (1B).

58. To prepare a patient for transport, potential spinal injuries should be stabilized105 (1C). Fractures and dislocations should be reduced as much as possible to normal anatomic configuration (1C). Open wounds should be covered (1C).

59. An uninjured patient who is completely alert and shivering may be treated without being transported to a hospital (1B).

60. If injuries meet trauma criteria, a patient should be transported to a trauma center (1B). An asphyxiated patient should be transported to a hospital for observation (1B).

61. A patient with moderate to severe hypothermia who is hemodynamically stable can be transferred to the closest hospital or other appropriate medical facility such as a rural clinic (1C). A patient who is hemodynamically unstable or who has a core temperature less than 281C should be transferred to a hospital capable of providing critical care and ECC, if possible. If this will require significant additional time—generally more than an additional hour—of non– critical care transport the patient should first be stabilized at a closer facility (1C). A patient in cardiac arrest should be transferred to a hospital capable of providing ECC if possible. If all other factors are equal, ECMO is preferable to CPB (1B). In geographic regions where there is no hospital capable of providing ECC or when a hospital capable of providing ECC is not accessible, transport a patient in cardiac arrest to the closest hospital where serum potassium can be measured and where resuscitation methods not involving ECC can be attempted for a patient whose serum potassium is 12 mmol/L or less. (Please see following section for use of biochemical markers.) (1C).

62. If an adult hypothermic patient has a potassium greater than 12 mmol/L, CPR should be terminated (1B).

63. An avalanche victim buried 35 minutes or less or with a core temperature of at least 321C should receive standard resuscitation, including CPR if in cardiac arrest67,120 (1C). If there is ROSC, the victim should be transported to the nearest hospital that can manage any associated injuries (1C). An avalanche victim who was buried more than 35 minutes or who has a core temperature less than 321C and has detectable vital signs should be transported to the nearest hospital or rural clinic for active rewarming (1C). If there are no vital signs and the airway is patent, CPR should be started67 (1B). An avalanche victim in cardiac arrest with an airway that is definitely obstructed should not be resuscitated if burial time was greater than 35 minutes or core temperature is less than 321C67 (1C). If there is any chance that the airway was patent, a short trial of CPR is warranted (1B).

64. An avalanche victim with CPR in progress should be transported to a hospital with the capability of performing extracorporeal rewarming if possible (1B). If it is not practical for the patient to go directly to a hospital that can perform extracorporeal rewarming and serum potassium has not already been measured, the patient should be transported to a hospital or clinic capable of measuring serum potassium (1C). Resuscitation should be continued only if serum potassium is 12 mmol/L or less (1B).

 

| Tags : hypothermie

05/11/2014

Heatpac: Ancien, oublié mais reste d'actualité

Pre-hospital torso-warming modalities for severe hypothermia: a comparative study using a human model

Hultzer M. et Al. CJEM 2005;7(6):378-386

Objective: To compare 5 active torso-warming modalities in a human model of severe hypothermia with shivering heat production inhibited by intravenous meperidine.

Methods: Six subjects were cooled on 6 different occasions each, in 8°C water, for 30 minutes or to a core temperature of 35°C. Spontaneous warming was the first torso-warming modality to be tested for every subject, and results served both as a comparative control and for determination of the meperidine dose for subsequent trials. Meperidine (1.5 mg/kg) was administered during the final 10 minutes of immersion to suppress shivering. Subjects were removed from the water, dried and insulated for 30 minutes, followed by 120 minutes of 1) forced-air warming with either a 600-W heater and commercial soft warming blanket; or 2) a 600-W heater and rigid cover; or 3) an 850-W heater and rigid cover; or 4) a charcoal heater on the chest; or 5) direct body-to-body contact with a normothermic partner. Supplemental meperidine (to a maximum cumulative dose of 3.2 mg/kg) was administered as required to inhibit shivering.

Results: The initial post-cooling afterdrop was approximately 1.0°C. After 30 minutes, core temperature continued to drop by 0.45°C in spontaneous and body-to-body warming modalities. This post-warming afterdrop was significantly less with 600-W heater and rigid cover and the charcoal heater (0.26°C) and the least with 850-W heater and rigid cover (0.17°C). Core rewarming rates were highest using 850-W heater and rigid cover (1.45°C/hr), with charcoal heating and 600-W rigid heater (0.7°C/hr), 600-W heater and blanket (0.57°C/hr) and body-to-body warming (0.52°C/hr) being more effective than spontaneous warming (0.36°C/hr).

Conclusions: In non-shivering subjects, external heat application was effective in attenuating core temperature afterdrop and facilitating safe core rewarming; this was more evident when heat was delivered preferentially to the chest, and dependent upon the amount of heat donated. The modalities studied appear sufficiently practical and portable for pre-hospital use and should be considered for such situations, particularly in rural or wilderness locations where anticipated transport time to the hospital exceeds 30 minutes.

charcoal.jpeg

 

Accéder à une étude technique

| Tags : hypothermie

04/11/2014

Gelures: L'expérience indienne

Management of Cold Injuries 

Hota PK et Al. Surgical Research Updates, 2013, 1, 20-25

Un article produit par une équipe ayant une grande connaissance de cette pathologie. La place de l'oxygénothérapie hyperbare y est mise en avant.

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Cold injuries are very common among the troops deployed in high altitude regions. Now days, it is also seen  among the civilian populations like mountaineers and winter sportspersons. There is no definitive treatment protocol  available for this entity. In this study, 234 patients of various degrees of cold injuries were treated with a standard  protocol of multidrug therapy with a view to combat the effects of cold injury at various steps of pathogenesis. Deep frost  bite cases were subjected to Hyperbaric Oxygen therapy (HBOT). An encouraging result was found in our study with this  protocol. There was less morbidity. Healing time, hospital stay and loss of digits were less. Multidrug therapy with  Pentoxyphylline, Ibuprofen and soluble aspirin was a better treatment modality than single drug used in the treatment of  cold injuries. HBOT was found to reduce morbidity to a great extent along with saving a number of digits from  amputation. 

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| Tags : gelures

24/05/2014

Gelures: Une vision actualisée 2014

Frostbite: a practical approach to hospital management

 
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La prise en charge des gelures évolue notamment par l'apport de la perfusion d'iloprost dans les formes les plus graves et du positionnement en cours de la thrombolyse. Ce document fait une synthèse des données actuelles.
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Frostbite presentation to hospital is relatively infrequent, and the optimal management of the more severely injured patient requires a multidisciplinary integration of specialist care. Clinicians with an interest in wilderness medicine/ freezing cold injury have the awareness of specific potential interventions but may lack the skill or experience to implement the knowledge. The on-call specialist clinician (vascular, general surgery, orthopaedic, plastic surgeon or interventional radiologist), who is likely to receive these patients, may have the skill and knowledge to administer potentially limb-saving intervention but may be unaware of the available treatment options for frostbite. Over the last 10 years, frostbite management has improved with clear guidelines and management protocols available for both the medically trained and winter sports enthusiasts. Many specialist surgeons are unaware that patients with severe frostbite injuries presenting within 24 h of the injury may be good candidates for treatment with either TPA or iloprost.

Frostbite.jpg

In this review, we aim to give a brief overview of field frostbite care and a practical guide to the hospital management of frostbite with a stepwise approach to thrombolysis and prostacyclin administration for clinicians

| Tags : gelures