Although some medications only come in one formulation, many can be administered by more than one method. In the tactical environment, the decision on which formulation to use can be influenced by both the desired clinical effects and by the effect that a route of administration can have on your resources and time.
Within reason, a general rule is that pain relief should be provided as quickly as the situation allows to avoid unnecessary suffering on the part of the casualty. But that does not mean that because an IV preparation of a medication has the fastest onset of action it will always be best.
Sometimes, your objective will be a more sustained level of analgesia, and that might be accomplished better with an IM preparation or an oral/transmucosal preparation. This is particularly true during evacuations; even more so if a medical attendant is not present to control pain during the transit.
Also, some medications will alter a casualty’s mental status, and you may prefer to have those effects minimized, which can sometimes be a factor in which method of administration you choose.
Additionally, from a resource management perspective, if a casualty can take a medication orally or by transmucosal administration, you may save time from establishing IV or IO access and guard supplies that can be used for a future casualty. This may also reduce the potential workload on evacuation medical assets or receiving medical facilities later in the continuum of that casualty’s care.
The six routes of administration we will go over during this module are oral, transmucosal, intranasal, intramuscular, intraosseous, and intravenous. The table on the following slide shows some of the general characteristics of each route and can help highlight the pros and cons of a given method of administration when you are deciding on which route to consider, if multiple options are available. In the order they are listed, the onsets of action and medication peaks are faster with administration directly in the bloodstream, but the duration may be longer with those methods that have a slightly slower onset of action.
Another concept to remember is that it is always important to ensure that there are no medication errors by confirming the five “rights”: right patient, right medication, right dose and concentration, right time, and right route of administration. This is usually part of our standard operating procedures in a hospital setting, but the same safety concerns apply in the prehospital setting, and the same standard of care applies.
Additionally, it is important to check the casualty’s allergies before the administration of any medication, as well.