Wilderness and Rescue Medicine 7th Edition Jeffrey Isaac, PA-C and David E. Johnson, MD

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Section IV: Trauma

viscous lidocaine or spray benzocaine can be very effective when combined with systemic analgesics to decrease the discomfort of wound debridement and irrigation.

by injection. Some of these can also be given by intranasal atomizer, as can the opioid antagonist (antidote) naloxone. Use of these medications and routes is generally restricted to advanced level providers. As any practitioner using these medications should be aware, opioids and benzodiazepines are central nervous system depressants and can depress respiration, mental status, and level of consciousness. When used in combination, the effects are cumulative. Care must be taken to use the lowest effective dose and to monitor the patient carefully. Risk Versus Benefit The goal of pain management in the wilderness and rescue setting is an awake patient with toler- able pain. When using opioids and benzodiaz- epines, titrate the dose gradually to achieve the desired effect. Avoid the temptation or pressure to give a large dose initially or to increase the dose quickly. Putting your patient to sleep will run the risk of respiratory depression, aspiration, airway obstruction, and the development of ischemia or other problems that may go undetected. An awake patient will tell you when the leg goes numb or the splint is beginning to cause an abra- sion. An awake patient will provide feedback on the success or failure of your treatment. An awake patient, even with analgesics on board, will not hurt herself by overusing an injured body part. This reassurance, however, does not extend to local anesthetic agents. These medications can eliminate pain perception, even if the patient is wide awake. Injecting a joint with lidocaine, for example, can allow the patient to cause significant self-inflicted injury without feeling anything. A patient given anesthetic eye drops could tear or abrade the cornea just by rubbing the eye without the benefit of painful feedback. The use of injected and ophthalmic anesthetics should include a plan for minimizing these risks, such as not allowing a patient to return to normal activity until the anesthetic has worn off. Dispensing or administering any medication carries considerable responsibility, requires

General Principles

Anesthetics like lidocaine can be injected into wounds to block the pain of exploration and cleaning. Lidocaine is also available in a viscous solution for topical use when injection is not feasible.

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General Principles

Injectible Anesthetics

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Injectable Anesthesia: • lidocaine, bupivacaine, diphenhydramine • intradermal infiltration

• intraarticular • digital block • hematoma block

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Ketamine is another anesthetic that may be used by advance practitioners in the field. It is systemic rather than local, and can be given orally or by intramuscular or IV injection. At lower dosages it is a good pain reliever when use alone, and even better when combined with a low dose of an opioid. A separate class of drugs worthy of mention for pain management is the benzodiazepines, such as diazepam and lorazepam. These are anxiolytics (anti-anxiety), not analgesics, but can substan- tially enhance the pain-relieving effect of opioids and NSAIDs. An opioid at the lower end of its dose range combined with a low dose of benzo- diazepine may have a better effect than a larger dose of either drug alone. In a well-controlled setting, opioids, benzodiaz- epines, and ketamine are typically administered