La NAC: Intéressante en role 1: Probable ?

La N-acétylcystéine ou acétylcystéine ou NAC est un acide aminé non essentiel, qui stimule la production de glutathion, un antioxydant. Elle est surtout connue comme agent mucolytique. En médecine d'urgence son emploi lors d'intoxication au paracétamol est parfaitement validé. Moins connues sont les emplois de cet agent antioxydant dans deux types d'indication qui nous intéressent. 

La première est le traumatisme sonore aigu notamment après explosion (1) ou tir (2) où il semblerait que la démarche classique [repos auditif, corticothérapie+/- vasodilatateurs] (3, 4) évoluerait vers une statégie associant le repos, la corticothérapie et unhe stratégie antioxydante précoce incluant le recours précoce à la N Acétyl Cystéine(5, 6).

La seconde porte sur la réduction des séquelles neurologiques après blast cérébral (7). Cet intérêt pour les effets anti-oxydants ne sont pas nouveaux et les effets «protecteurs» sont mis en avant également au niveau pulmonaire (8), rénale (9) et hépatique (10).

Si tout ceci reste à valider (11, 12), il semble que l'intégration de cette molécule ancienne soit d'un intérêt réel pour la prise en charge du combattant blasté ou exposéà un TSA à condition que l'administration soit précoce  (<1h) (13) et donc que la N Acétyl Cystéine soit disponible en rôle 1

Causes de DC évitables: Actualisation UK

Identifying future ‘unexpected’ survivors: a retrospective cohort study of fatal injury patterns in victims of improvised explosive devices

1. Singleton JAG et All.  BMJ Open. 2013 Aug 1;3(8). pii: e003130. doi: 10.1136/bmjopen-2013-003130.

 

To identify potentially fatal injury patterns in explosive blast fatalities in order to focus research and mitigation strategies, to further improve survival rates from blast trauma.

DESIGN:

Retrospective cohort study.

PARTICIPANTS:

UK military personnel killed by improvised explosive device (IED) blasts in Afghanistan, November 2007-August 2010.

SETTING:

UK military deployment, through NATO, in support of the International Security Assistance Force (ISAF) mission in Afghanistan.

DATA SOURCES:

UK military postmortem CT records, UK Joint Theatre Trauma Registry and associated incident data.

MAIN OUTCOME MEASURES:

Potentially fatal injuries attributable to IEDs.

RESULTS:

We identified 121 cases, 42 mounted (in-vehicle) and 79 dismounted (on foot), at a point of wounding. There were 354 potentially fatalinjuries in total. Leading causes of death were traumatic brain injury (50%, 62/124 fatal injuries), followed by intracavity haemorrhage (20.2%, 25/124) in the mounted group, and extremity haemorrhage (42.6%, 98/230 fatal injuries), junctional haemorrhage (22.2%, 51/230 fatal injuries) and traumatic brain injury (18.7%, 43/230 fatal injuries) in the dismounted group.

CONCLUSIONS:

Head trauma severity in both mounted and dismounted IED fatalities indicated prevention and mitigation as the most effective strategies to decrease resultant mortality. Two-thirds of dismounted fatalities had haemorrhage implicated as a cause of death that may have been anatomically amenable to prehospital intervention. One-fifth of the mounted fatalities had haemorrhagic trauma which currently could only be addressed surgically. Maintaining the drive to improve all haemostatic techniques for blast casualties, from point of wounding to definitive surgical proximal vascular control, alongside the development and application of novel haemostatic interventions could yield a significant survival benefit. Prospective studies in this field are indicated.

Cette publication est très importante car elle insiste sur l'absolue nécessité de poursuivre les efforts en vue de prévenir le trauma aussi bien en matière de protection balistique, de réduction des délais de transports pour permettre la prise en charge d'hémorragie intra-cavitaires et l'aspect fondamental d'arrêter toutes les hémorragies sur le terrain notamment pas la mise en oeuvre d'une nouvelle catégorie de garrots pour les hémorragies jonctionnelles (voir 1, 2, 3, 4, 5, 6)

Les morts par IED sont plus sévèrement atteints dans un véhicule qu'à pied.

58% des Décès sont liés à plus de 2 causes potentiellement évitables

Les causes de décès ne sont pas les mêmes en combat à pied ou en véhicule

Exposition répétées: Plus graves ! ou ?

Primary blast survival and injury risk assessment for repeated blast exposures

Panzer MB et all. J Trauma. 2012;72: 454–466.

Les conflits afghnas et irakiens ont vu les personnels des armées occidentales confrontées à de nouvelles modalités d'exposition à des ondes de surpression. Leur caractèes répété est responsable de lésions plus graves. Cet article actualise un certain nombre de données.

Ces quelques diagrammes expriment de manière très claire la relation entre le pic de pressions, sa durée et la répétition sur la survie et les lésions observées.

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BACKGROUND:

The widespread use of explosives by modern insurgents and terrorists has increased the potential frequency of blast exposure in soldiers and civilians. This growing threat highlights the importance of understanding and evaluating blast injury risk and the increase of injury risk from exposure to repeated blast effects.

METHODS:

Data from more than 3,250 large animal experiments were collected from studies focusing on the effects of blast exposure. The current study uses 2,349 experiments from the data collection for analysis of the primary blast injury and survival risk for both long- and short-duration blasts, including the effects from repeated exposures. A piecewise linear logistic regression was performed on the data to develop survival and injury risk assessment curves.

RESULTS:

New injury risk assessment curves uniting long- and short-duration blasts were developed for incident and reflected pressure measures and were used to evaluate the risk of injury based on blast overpressure, positive-phase duration, and the number of repeated exposures. The risk assessments were derived for three levels of injury severity: nonauditory, pulmonary, and fatality. The analysis showed a marked initial decrease in injury tolerance with each subsequent blast exposure. This effect decreases with increasing number of blast exposures.

CONCLUSIONS:

The new injury risk functions showed good agreement with the existing experimental data and provided a simplified model for primary blast injury risk. This model can be used to predict blast injury or fatality risk for single exposure and repeated exposure cases and has application in modern combat scenarios or in setting occupational health limits.

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Audition du combattant et blast

Ear injuries sustained by British service personnel subjected to blast trauma

Breeze J. et all. The Journal of Laryngology & Otology (2011), 125, 13–17

Objectives:

To describe the pattern of ear injuries sustained by all British servicemen serving in Iraq and Afghanistan between 2006 and 2009; to identify all servicemen evacuated to the Royal Centre for Defence Medicine following blast injury; to ascertain how many underwent otological assessment; and to calculate the incidence of hearing loss.

Design and setting:

A retrospective analysis of data obtained from the Joint Theatre Trauma Registry and the Defence Analytical and Statistics Agency, together with audiometry records from the University Hospitals Birmingham National Health Service Trust.

Results:

Ear damage was present in 5 per cent of all British servicemen sustaining battle injuries. Tympanicmembrane rupture occurred in 8 per cent of personnel evacuated with blast injuries. In 2006, 1 per cent of servicemen sustaining blast injury underwent audiography; this figure rose to 13 per cent in 2009. Fifty-three per cent of these audiograms were abnormal.

Conclusion:

The incidence of tympanic membrane rupture was higher than that found in previous conflicts. Otological assessment prior to and following military deployment is required  to determine the incidence of ear injury amongst British servicemen following blast trauma.