21/11/2010
Pansements hémostatiques: Une vision US
Prehospital topical hemostatic agents – A review of the current literature
PHTLS Executive Council
Lance E. Stuke, M.D. MPH
Background: The 6th edition of the PHTLS textbook discusses three topical hemostatic agents which were approved by the U.S. Food and Drug Administration and available for prehospital use at the time: HemCon dressing, QuikClot, and TraumaDex. Data on these products was based primarily on anecdotal military reports and very little data was available on their use in the civilian prehospital setting. Several new products have arrived on the market after the release of the 6th edition of PHTLS and several important new studies have been published which will be reviewed here. The vast majority of these products have been researched and developed for use in the military setting in Iraq and Afghanistan although some limited civilian data is also available.
The perfect hemostatic dressing does not exist. Ideally, the dressing should be lightweight, easy to store, and able to be rapidly applied to a hemorrhaging wound. It should be conformable to the wound, allowing the hemostatic agent to reach areas of injury which are difficult to access with direct pressure (i.e. deep groin wounds). The dressing should cause minimal local tissue destruction, be easily removable from the wound, and not contain particles which can spread systemically. Finally, the dressing must not be washed away by rapid bleeding from high-flow blood vessels.
Manufacturers have tried various methods to deliver hemostatic agents into bleeding wounds. Some products are packaged into a granular form which can be poured directly into the wound. Others are incorporated into a dressing or mesh which allows the provider to apply direct pressure to the site of injury. This dressing can be formed either as a rigid bandage, a small bag, or a gauze which must be unrolled prior to application. Each method of preparation has distinct advantages and disadvantages depending on the location and type of injury being treated.
Literature and Product Review:
HemCon: HemCon dressing (Hemorrhage Control Technologies, Portland, OR), is composed of chitosan, a substance derived from arthropod skeletons. Chitosan dressings are thought to function by mechanically sealing the wound and adhering to surrounding tissue. HemCon is a dual-sided 4 x 4 inch rectangular bandage: a chitosan-containing active side which must be placed directly on the wound and a nonstick side which the provider uses to apply pressure. The efficacy of HemCon depends entirely on the bandage adhering well to the wound, which is difficult in wounds which aren’t flat and easily accessible. The bandage isn’t flexible and can break when forced into a wound. It is best applied to flat, superficial wounds which are easily accessible. HemCon has been studied in both the military and civilian settings. The military demonstrated a 97% success rate in controlling bleeding with HemCon.1,2 The civilian experience has been less optimistic, controlling bleeding in 27 of 34 cases studied (79%). Of the seven failures, six were felt to be due to user error, possibly due to less training by civilian EMS providers in the proper use of the product.3 An additional study using a complex groin injury model in swine noted an increase in the rate of rebleeding and mortality between those treated with HemCon versus QuikClot. The authors noted that application of HemCon was more difficult than other agents and all failures of HemCon were due to the bandage not adhering to the injured tissue to which it was applied.4
As previously noted, a disadvantage of the HemCon dressing is that it is relatively non-conformable and difficult to pack into deeper wounds. ChitoFlex is the latest development from HemCon Medical Technologies. It utilizes the same chitosan-based hemostatic agent but packages it into a gauze form. This allows the dressing to be packed into deep bleeding wounds for improved access to the site of hemorrhage. ChitoFlex is available in several sizes, including 1”x3”, 3”x9”, and as a 3”x28” roll. In one study, ChitoFlex was found to be equivalent, but not superior to QuikClot and Celox (a chitosan granule).5
WoundStat: WoundStat was an FDA-approved mineral-based agent consisting of granular smectite, a nonmetallic clay. When the granules were exposed to blood they absorbed water, swelled, and formed a clay paste with strong adhesiveness to the surrounding tissue. Initial studies were promising6,7,8 and it was used by the U.S. Army for a short time. However, later data demonstrated that the granules could cause injury to the blood vessels and make repair difficult. The granules were also shown to enter the circulatory system and cause thrombosis in distal organs.9 Because of these potentially serious side effects, the U.S. Army announced in April 2009 that WoundStat would no longer be used by their medical personnel.
QuikClot: QuikClot (Z-Medica, Wallingford, CT) is a granular product consisting of kaolin, which is a combination of inert minerals such as silicon, aluminum, magnesium, and sodium found in volcanic rock. When placed in a bleeding wound, it absorbs water thereby increasing the local concentration of clotting factors, platelets, and red blood cells to stimulate clot formation. A byproduct of its mechanism is a severe exothermic reaction, with heat generation of up to 70̊ C (158o F). This heat generation causes local tissue destruction and even burns. QuikClot has been studied in both the military and civilian sector, with up to 92% effectiveness in stopping hemorrhage.10 QuikClot was issued to U.S. soldiers in the Iraq and Afghanistan conflicts. Civilian use has been by a wide range of providers, including EMT/firefighters, paramedics, and police. Examples of civilian use include treatment of severe lacerations, gunshot wounds to the neck and even hemodialysis catheter dislodgement. Trauma surgeons have also used QuikClot for successful treatment of bleeding during surgery in the chest, abdomen, and pelvis. QuikClot was noted to have two significant weaknesses. Since it is a granular powder poured into a wound, it had limited usefulness in high-pressure bleeding (i.e. femoral artery bleed)as the granules were washed away by the bleeding before they were able to form a clot. Furthermore, the heat generated from its use was associated with several burns.
QuikClot production was stopped after development of several newer generation products. These newer generation products have minimal heat production and are packaged both as gauzes and in a bagged form. Currently Z-Medica sells QuikClot packaged in 2”x2” and 4”x4” gauze pads for use on superficial lacerations which don’t have severe bleeding. QuikClot has also developed a small kaolin-impregnated pad (QuikClot ACS+) and as a laparotomy pad (QuikClot Trauma Pad) for use by trauma surgeons in the operating room for cases of severe bleeding during surgery. This later product remains in the research phase and is not yet approved for widespread use.
QuikClot Combat GauzeTM is a 3”x4 yard long roll of nonwoven gauze impregnated with kaolin. Combat Gauze has all the advantages of normal gauze (easy application, flexible, large coverage area, and easily removable) with the additional advantage of hemostatic function from the kaolin. It is designed for packing into deep wounds which are actively bleeding (i.e. arterial injury in the groin). Prehospital personnel can also use combat gauze as they would any standard Kerlix gauze. Combat Gauze was recently compared to several newer generation products, including the HemCon RTS, and found to be superior and had no apparent side effects.11 Currently, QuikClot Combat Gauze is the only product endorsed by the Tactical Combat Casualty Care Committee and they recommend it as first line treatment for life-threatening hemorrhage on external wounds not amendable to direct pressure and tourniquet placement.
Summary:
- Numerous topical hemostatic products have been developed and released onto the market.
- Some of these products have since been discontinued, while others are widely used.
-Economic and medical considerations continue to make this a rapidly evolving and growing area of prehospital care. It is important for the EMS provider to remain cognizant of these products and their advantages, disadvantages, and complications as they continue to evolve.
PHTLS Recommendation: Topical hemostatic agents may be used to control hemorrhage occurring in sites not amenable to tourniquet placement and which cannot be controlled by direct pressure alone.
Bibliography
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Achneck HE, Sileshi B, Jamiolkowski RM, et al. A comprehensive review of topical hemostatic agents: Efficacy and recommendations for use. Annals of Surgery 2010; 251: 217-228.
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Mabry R and McManus JG. Prehospital advances in the management of severe penetrating trauma. Crit Care Med. 2008:36(7);S258-266.
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Brown MA, Daya MR, Worley JA. Experience with chitosan dressings in a civilian EMS system. J Emerg Med. 2009;62:239-243.
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Kozen BG, Kircher SJ, Henao J, et al. An alternative hemostatic dressing: comparison of CELOX, HemCon, and QuikClot.Acad Emerg Med. 2008; 15:74-81.
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Devlin JJ, Kircher S, Kozen BG, et al. Comparison of ChitoFlex, CELOX, and QuikClot in control of hemorrhage. J Emerg Med. 2009 Apr 1 (Epub ahead of print).
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Ward KR, Tiba MH, Holbert WH, et al. Comparison of a new hemostatic agent to current combat hemostatic agents in a swine model of lethal arterial hemorrhage. J Trauma. 2007;63:276-284.
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Kheirabadi BS, Edens JW, Terrazas IB, et al. Comparison of new hemostatic granules/powders with currently deployed hemostatic products in a lethal model of extremioty arterial hemorrhage in swine. J Trauma. 2009;66:316-328.
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Arnaud F, Parreno-Sadalan D, Tomori T, et al. Comparison of 10 hemostatic dressings in a groin transaction model in swine. J Trauma. 2009;67:848-855.
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Bheirabadi BS, Mace JE, Terrazas IB, et al. Safety evaluation of new hemostatic agents, smectite granules, and kaolin-coated gauze in a vascular injury wound model in swine. J Trauma. 2010;68:269-278.
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Rhee P, Brown C, Martin M, et al. QuikClot use in trauma for hemorrhage control: case series of 103 documented uses. J Trauma. 2008;64:1093-1099.
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Kheirabadi BS, Scherer MR, Estep JS, et al. Determination of efficacy of new hemostatic dressings in a model of extremity arterial hemorrhage in swine. J Trauma. 2009;67:450-460.
| Tags : pansement
19/11/2010
Le traitement de l'eau
Household Water Purification: Low-Cost Interventions
Col VK Agrawal (Retd)*, Brig R Bhalwar+
Abstract
Numerous studies have shown that improving the microbiological quality of household water by point-of-use treatment reduces diarrhoea and other waterborne diseases. The most promising and accessible of the technologies for household water treatment are filtration with ceramic filters, chlorination with storage in an improvised vessel, solar disinfection in clear bottles by the combined action of UV radiation and heat, thermal disinfection (pasteurization) in opaque vessels with sunlight from solar cookers or reflectors and combination systems employing chemical coagulation-flocculation, sedimentation, filtration and chlorination. However each of these technologies have limitations and effectiveness can be increased by use of two or more treatment systems in succession for improved treatment and the creation of multiple barriers. In particular those treatments that provide no residual disinfectant, such as boiling, solar treatment, UV disinfection with lamps and filtration could be followed by chlorination to provide a multibarrier approach. Water purifiers based on multiple interventions such as filtration/ultra filtration/ activated carbon adsorption / UV rays disinfection are available in the market which can be used to purify the water at point of use. Water purifiers based on single interventions like candle filters, resins filters or ultraviolet lamp can be used in most places being supplied water after purification. Troops on operational move can purify water by fabric/resins filtration and chlorine disinfection or by flocculent-disinfectant.
Altitude et acclimatation: Pas si simple
Determinants of Acclimatisation in High Altitude
Col VS Syed*, Maj Gen S Sharma+, Col RP Singh#
Abstract
Background: A total of 31 cases of effects of high altitude were admitted to a field hospital from a particular sector during the year 2008. This study was hence undertaken to see the efficacy of acclimatisation as well as outline the determinants of acclimatisation
Methods: The study monitored the transients in the acclimatisation period as well as laid down the guidelines to certify the fitness after the acclimatisation period.
Result: Almost 4.70% of transients were found unfit to proceed to higher altitudes even after acclimatisation. Tachycardia with oxygen saturation below 90% by digital pulse oximetry were the parameters found to be statistically significant as an indicator declare a person as not fully acclimatised or otherwise.
Conclusion: The administrative authorities must ensure that an individual is fully acclimatized, based on the fitness certificat
issued, before being dispatched to their units located in high altitude areas.
MJAFI 2010; 66 : 261-265
Masque laryngé: Êtes vous sûr ?
La place des dispositifs laryngés pour le contrôle des voies aériennes en condition de combat est très limitée. Ces dispositifs ne font pas partie des mesures recommandées par le TCCC et le BATLS, car ils ne ne répondent pas aux critères essentiels qui sont d'assurer l'ouverture des voies aériennes en cas de plaie maxillo-faciale, ils ne protègent pas des risques d'inhalation, ils ne dispensent pas de la réalisation d'une sédation, ils sont susceptibles de mobilisation, enfin ils ne représente pas la première ligne de traitement pour la prise en charge d'une détresse respiratoire en condition de combat.
L'article suivant expose un certain nombre de désagrément lié à l'emploi de l'un de ces dispositifs.
Indian Journal of Anaesthesia 2009; 53 (4):414-424
Troubleshooting ProSeal LMA
Bimla Sharma, Jayashree Sood , Chand Sahai , V P Kumra
Summary
Supraglottic devices have changed the face of the airway management. These devices have contributed in a bigway in airway management especially, in the difficult airway scenario significantly decreasing the pharyngolaryngeal morbidity. There is a plethora of these devices, which has been well matched by their wider acceptance in clinical practice. ProSeal laryngeal mask airway (PLMA) is one such frequently used device employed for spontaneous as well as controlled ventilation. However, the use of PLMA at times may be associated with certain problems. Some of the problems related with its use are unique while others are akin to the classic laryngeal mask airway (cLMA). However, expertise is needed for its safe and judicious use, correct placement, recognition and management of its various malpositions and complications. The present article describes the tests employed for proper confirmation of placement to assess the ventilatory and the drain tube functions of the mask, diagnosis of various malpositions and the management of these aspects. All these areas have been highlighted under the heading of troubleshooting PLMA. Many problems can be solved by proper patient and procedure selection, maintaining adequate depth of anaesthesia, diagnosis and management of malpositions. Proper fixation of the device and monitoring cuff pressure intraoperatively may bring down the incidence of airway morbidity.