The aim of this study was to assess the level of knowledge of IN analgesia among FMHS physicians. The majority (77.6%) of physicians in the sample group stated that they were well acquainted with the technique of IN analgesia. However, only four physicians scored a maximum mark of five out of five on the multi-choice questions; 90.7% of the respondents declared an interest in following a specific training course on IN pain control. Although the FMHS doctors know about this technique, some supplementary training is necessary, together with the establishment of standardized protocols.
Civilian (28.9%) and military (18.3%) scientific articles or discussions between peers (16.8%) are the main sources of information for this method of analgesia. Only a small percentage (3.7%) know the IN route thanks to a training course, given at the Ecole du Val-de-Grâce (the French military medical academy), during a dedicated module on tactical management of combat casualties (27).
In all,62.5% of the sample group had a qualification in emergency medicine. Such training in emergency medicine is fundamental for a military GP as it gives the physician an indispensable level of autonomy in deployments in austere setting. For example, during French military operations in the Sahel (an area 10 times as wide as France), the evacuation time between the combat zone and the nearest field hospital can reach 6 to 12 hours (6–7). The frontline GPs and emergency medicine physicians, assisted by the nurses and combat medics, need to take complete charge of patients in very rudimentary conditions. The practice of emergency medicine is an important factor in the degree of knowledge concerning IN analgesia. Qualified personnel who regularly work in emergency medicine use this technique more than others.
Our study highlights the need for an initial training course, which could be provided by the Ecole du Val-de-Grâce (the French military medical academy), either at the end of the internship period, as a supplementary module, or prior to departure on deployment, as part of the tactical management of combat casualties. The results also underline the need for continuous professional development, both theoretical and practical, as regards IN analgesia. The FMHS physicians provide the medical support of military units during various missions involving very different field conditions. This governs the degree of engagement of these physicians in the medical outposts. The sea, mountains, and airborne or special operations are particularly austere environments, exacting and isolating for the soldiers but equally so for the physicians supporting them. From the respondents, the researchers have arbitrarily taken a sample of physicians who are assigned to highly operational units (Special Forces/GIGN [National Gendarmerie Intervention Group], paratroopers, medical evacuation [MEDEVAC] and search and rescue [SAR]) and naval embarkation units) or who are deployed in specific situations (mountain troops, Civil Security, BSPP (Paris Fire Brigade) and BMPM (Marseille Naval Fire Battalion)). The physicians assigned to these units have more knowledge of, and are more likely to use, IN analgesia.
Only a small proportion of the doctors questioned had already used the IN route for pain control and then mainly in pre-hospital medical care and in France. The most frequently used drug is ketamine, alone or in association with midazolam. Ketamine is a substance that is well-known to military physicians, because it is reliable and efficacious in controlling acute pain on the battlefield (28). Ketamine has the effect of stimulating the cardiovascular system (central sympathomimetic action) while having little effect on ventilation (28). In association with midazolam, the psychodysleptic side effects seen with IN ketamine are reduced. However, to our knowledge, no study has yet proven that joint administration of ketamine and midazolam diminishes this side effect. Four of the doctors used midazolam on its own but given that this drug has hypnotic properties it would seem to be more appropriate for sedation (of psychotic patients for instance) rather than pain control.
Despite the more numerous studies on the use of opioids (sufentanil and fentanyl) in IN analgesia, particularly in a pre-hospital context, both drugs are less frequently used by military doctors (23% of use). These substances are more lipophilic than ketamine and, consequently, the molecules are absorbed better by the nasal mucosa. However, because of their hypotensive properties and certain adverse effects, notably reducing respiration, they merit caution as regards their use for a combat casualty with hemorrhagic shock. On the other hand, an advantage of this class of therapeutics is the possibility of reversing any major adverse effects by the administration of an antidote (naloxone), initially using the same delivery route. The IN administration of this drug is available to non-medical professionals (police, paramedics etc.) in the USA for treating victims of an opioid overdose (29).
In our sample group, the physicians showed a preference, on national territory at least, for using ketamine. In familiarizing themselves with this drug, they will be capable of using it for a combat casualty in a critical state during deployments.
Several procedures are currently being introduced to extend the use of IN analgesia into combat zones. Those military doctors whose role is supporting the National Gendarmerie Intervention Group (GIGN) have put in place a protocol for administering sufentanil and ketamine via the IN route (30). At the moment, the MAD device is only available on demand in exceptional cases during deployments, but it should be available for routine ordering from 2021 onwards.
Finally, a ketamine pulverization device for IN analgesia is being developed currently by the FMHS Central Pharmacy and this could soon be made available as a means of auto-administration for all servicemen and women. The idea is to include this device in the personal kit of each soldier, actually this kit is composed of a morphine syrette (a 10 mg subcutaneous dose) for analgesia (31). It would be interesting to carry out a new study in a few year to assess the impact of introducing both these standardized guidelines and the new injection device on the level of knowledge and application of this method of analgesia.