Nowhere is acute pain more evident than in the prehospital emergency setting. It is here ƒ on the roadside, at the workplace and in the home ƒ that most painful injuries occur and where pain is often the most severe and debilitating. Thus, the prehospital setting also allows for the most significant impact on pain management. Although we understand the pathophysiology of pain better than ever, it remains one of the most under-appreciated and under-treated conditions encountered by EMS personnel.
Virtually all health-care professions include in their code of ethics a statement stressing the importance of the alleviation of pain and suffering. However, as the transition is made from student to professional, and patient's faces become passing blurs in our memories, the significance of that statement is often forgotten. Therefore, in order to remain excellent providers, we must periodically refresh ourselves on the keys of pain management-particularly for pediatric patients who may be most neglected due to their inability to aptly communicate their pain.
The Broad Definitions
The single most common symptom of injury or disease, pain is an unpleasant sensory and emotional experience associated with actual or potential damage to tissues or the condition described in terms of such damage. Pain results from a combination of variables; a sensory stimulus is the primary event. Pain receptors (nociceptors) initiate pain signals by converting traumatic insults into electrical impulses. These pain impulses are then transmitted via the spinal cord to the brain stem, and then to the thalamus, cerebral cortex and limbic areas of the brain.
The impulses may be affected by chemical mediators (e.g., endorphins, enkephlins and dynorphins) during this transmission process, enhancing or inhibiting the perception of pain. Each person's unique memories, expectations and emotional status may modify the effect of these chemical mediators and, thus, the person's perception of pain. This entire process occurs on the subconscious level and is completed within milliseconds.
Pain may be classified as acute, chronic non-malignant or chronic malignant. Acute pain is of new onset, usually associated with trauma or inflammation, with a duration of less than six months. It serves as a warning mechanism that something is wrong.
Chronic pain is constant or recurring, without an anticipated or predictable end, and has a duration of greater than six months. Patients with chronic pain are generally under the care of a physician and have prescribed medications or other methods for reducing the pain.
Acute pain results in stimulation of the autonomic nervous system and is usually associated with sympathetic stimulation, resulting in the release of catecholamines (adrenaline) into the blood stream. This release manifests as increased pulse rate, increased contractility and cardiac output, sweating, tachypnea, bronchodilation and "nervousness." Parasympathetic stimulation is more likely to occur with chronic pain but may be seen with acute pain in some patients and may result in bradycardia, hypotension and syncope.
The end result of these two opposing sets of stimuli may vary considerably from person to person. For example, one patient may become hypotensive and faint after suffering a soft tissue injury, whereas another patient with a similar injury will become tachycardic and hypertensive. The very old and the very young are at greatest risk for developing complications secondary to pain.
However, pain is much more than an undesirable sensation. Untreated acute pain produces anxiety, depression and debilitation. It has also been shown to cause immune, cardiac and respiratory compromise, and to lengthen recovery time and hospitalization.
It's estimated that 75% of hospitalized patients with pain are under-treated. Emergency department (ED) patients are under-treated for pain as well. One large study showed that only 44% of patients presenting with long-bone fractures received analgesia. Although no prehospital statistics are available for review, it's likely that the incidence of the under-treatment of pain is even greater in the field. In most areas, paramedic students have relatively little interaction with pediatric patients. After joining the workforce, encounters with infants/children continue to be relatively infrequent. Given the lower comfort level that paramedics as a group have with pediatric patients, pain management is likely even more dismal for younger age groups.
Pain can be treated effectively only if the paramedic has an accurate understanding of the quality and quantity of pain being experienced. Making this determination is usually not difficult in the adult or older child with well-developed verbal skills. However, this may be difficult with younger children who can't verbalize their discomfort. Generally, any injury that would cause severe pain in an adult will also cause severe pain in a child, even if the child is unable to communicate that perception.
Approach children in a calm and non-threatening manner, keeping in mind that they often become very anxious when experiencing pain. Once the child is calmer, then movement is reduced and the pain level may decrease naturally. Continue to speak to the child by name and in a steady, gentle voice. In addition, because children respond best if approached on their own level, kneel or sit before interviewing and examining them.
For pediatric patients with potentially painful conditions, providers should ask if they're having pain and, if so, to rate the degree of pain using a facial analog chart. Ask the child to point to the face on the scale whose expression most accurately reflects their pain level. A zero-to-ten number scale, with zero equaling no pain and 10 equaling excruciating pain, is also effective for school-age children and adults with limited communication skills. The Wong-Baker FACES Pain Rating Scale (see below) should be used for preschool children and for adults who are incapable of comprehending the number scale.Source: FACES Pain Rating Scale. Wong on Web, 2002. www3.us.elsevierhealth.com/WOW/faces.html. Retrieved Feb. 20, 2006. From Hockenberry MJ, Wilson D, Winkelstein ML: Wong's Essentials of Pediatric Nursing, 7th ed. Mosby: St. Louis, 2005. p. 1259. Used with permission.
A thorough physical exam is essential. If the patient has been exposed to generalized or unknown trauma, your exam should include a thorough head-to-toe assessment with particular emphasis on neurologic and cardiovascular status. Evaluate breath and bowel sounds. Pay careful attention to volume and hydration status.
The physical exam is particularly important if narcotics are to be administered. Closed-head injury, hypotension and respiratory depression are contraindications for narcotics. Hypovolemia is a relative contraindication, increasing the likelihood of hypotension if narcotics are administered.
Reducing anxiety should always be the first step in pain management. Children generally have a positive image of EMS providers from TV shows and school programs. However, children are very perceptive and any hint of deception or apathy will quickly change that impression.
Trauma-induced pain is a common complaint among pediatric patients in the prehospital setting. Steps should be taken to alleviate pain before and during transport. An escalating treatment plan in which simpler approaches are tried first is preferred.
Distraction may be effective with some children. Simply asking a child about his family or a pet may provide some relief from pain. Similarly, covering a soft tissue injury so that a child can't see it may relieve anxiety. Another effective way to distract a younger child is to provide a stuffed animal for them to hold. Some ambulance services now routinely carry a supply of teddy bears or other popular characters for that purpose.
Patients experiencing moderate to severe pain secondary to isolated extremity trauma are good candidates for narcotic analgesia. The opiates and their synthetic analogs continue to be the standard for the relief of significant pain. These drugs have a proven track record for both safety and efficacy. The risk of addiction for a short course of narcotics in a pediatric patient is practically nil and should never be a deciding factor when considering pain relief. Withholding analgesics and other pain reducing treatment when no contraindications exist is inhumane and unacceptable.
Oral non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, are commonly used to treat fever and mild to moderate pain. These medications have little effect on the cardiovascular system and don't alter consciousness. However, the absorption of oral medications is unpredictable, making them undesirable for emergency use. These drugs should not be used as substitutes for more potent pain relievers. Toradol is the only drug of this type administered parenterally. It's occasionally used in the management of moderate to severe pain. It's effective at relieving certain types of pain, but should not be considered as a replacement for opiates for moderate to severe pain.
Nitrous oxide is used by some ambulance services, favoring its short half-life and ease of use. Nitrous oxide may be an effective agent for managing pain in children. However, some children are suspicious and afraid of the delivery mask. If capable, the child should be allowed to self-administer the medication. Many ambulance services no longer stock this drug due to the high incidence of abuse and the difficulty associated with accounting for use.
Morphine is the most widely used narcotic analgesic in the prehospital setting and continues to be the standard to which all others are compared. It has been in use for decades and has a proven safety record and predictable side effects. It has been used extensively in the pediatric population. When administered slowly and in small increments side effects can be minimized. A concomitantly administered antiemetic/potentiator may allow for a reduction in dosage and further decrease the probability of side effects.
The synthetic narcotic fentanyl is used by some flight programs and is an effective drug for the management of acute pain. It's 100 times more potent than morphine, less likely to cause respiratory depression and hypotension than other narcotics and has a relatively short half-life. Fentanyl lollipops are used by some EDs to provide sedation and analgesia for pediatric patients prior to painful procedures, such as suturing. The onset of action for this route of administration is approximately five minutes. Although a search of the literature failed to produce any evidence that this approach has been applied in the prehospital setting, this treatment option appears to hold some potential for field use.
Pain is generally under-treated in patients of all ages. Untreated pain may lead to compromised immune and cardiac function and may prolong recovery times. Although some progress has been made in the assessment and management of pain in the hospital environment, prehospital pain management has not kept pace, especially in the pediatric population. Children may be more difficult to communicate with and, thus, more difficult to assess. This obstacle often leads to overly conservative treatment by the prehospital health-care provider. Unfounded fears of drug side effects and addiction have also played a role.
However, because untreated pain may lead to serious emotional and physical consequences, prehospital providers should be aggressive in pain management in the absence of contraindications. An escalating approach works best. Distraction and reassurance are sometimes effective; if they are not, narcotic analgesics or nitrous oxide should be considered early in the management of patients with moderate to severe pain.
Editor's note: For more in-depth discussion of the three analgesics to use in the field, read "Simplifying Prehospital Analgesia" in July 2005 JEMS.
About the Author
Clyde Deschamp, PhD, NREMT-P, is associate professor and chair of the Department of Emergency Medical Technology at the University of Mississippi Medical Center. Contact him firstname.lastname@example.org.
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