Pain is the most common emergency complaint. The World Health Organization supports optimal pain treatment as a fundamental human right (who.int.easyaccess2.lib.cuhk.edu.hk/mediacetre/news/notes/2007/np31/en/). Several prehospital studies have shown inadequate analgesia for these patients. Factors associated with failures in the management of prehospital pain include underestimation of pain, underdosing of analgesia medications, underfrequency of dosing, and inappropriate withholding of analgesia. The importance of prehospital analgesia has been outlined by the Emergency Medical Services Outcomes Project in (the United States as follows: “the relief of discomfort might be the most important task EMS providers perform for the majority of their patients.” This sentiment was also advocated by the National Association of EMS Physicians (NAEMSP), who issued a position paper stating that the relief of pain should be a priority for every EMS system. A more to the point assessment of prehospital undertreatment of pain was given in a Basket editorial: “The blame for ‘oligoanalgesias’ must be laid at the door of physicians in authority who have, through ignorance, underplayed the physiologic and psychological benefits of analgesia and overplayed the potential deleterious side effects of agents that are commonly available.”
Describe the goals of prehospital analgesia and sedation.
Discuss barriers to the administration of prehospital analgesia.
Describe pain assessment and prehospital pain scales.
Describe available pharmacological interventions.
Describe available local and regional anesthesia.
Discuss nonpharmacological interventions and therapies.
Describe the development of analgesia and sedation protocols.
Pain complaints present unique challenges to EMS providers. These patients may be difficult, distraught, evasive, and seemingly unreasonable. A full understanding of the differing types of pain, their presentations, and a concise, systematic approach to the treatment of these patients is paramount to optimizing their care. Furthermore, it is important to note that there are advanced life support agencies functioning without access to controlled substances for their patients. It is therefore important for EMS medical directors to understand the importance of these concepts. It is the responsibility of EMS physicians and medical directors to ensure that the problem of oligoanalgesia is addressed in CQI and education programs.
DEFINITION OF PAIN
Pain is the most common reason for patients to seek medical attention in the United States. 1 The International Association for the Study of Pain (IASP) defines pain as “an unpleasant sensory and/or emotional experience associated with actual or potential tissue damage. It usually motivates the patient to withdraw from the offending stimulus.” 2 Pain is not only a sensory process, but also an affective, subjective phenomenon influenced by physiological processes and by diverse psychological and emotional processes. Most pain will resolve quickly once the stimulus is withdrawn. However, pain may at times persist despite stimulus removal and apparent healing. At other times, pain may develop in the absence of any detectable stimulus or damage.
TYPES OF PAIN
There are two categories of pain: acute and chronic. Acute pain is associated with an injury or pathological illness that resolves with the resolution of the inciting cause. Acute pain is mediated through nerve fibers that fire in response to chemicals released with tissue damage. Chronic pain lasts longer than would be expected for a given injury or pathological condition. The main types of pain include nociceptive, neuropathic, phantom, and psychogenic pain.
Acute pain is mediated through nociceptors (pain receptors) that send impulses from the peripheral nerve fibers to the spinal cord and the cerebral cortex of the brain. These receptors respond to a broad range of noxious stimuli (thermal, mechanical, and chemical). Nociceptive pain may also be categorized into visceral, deep somatic, and superficial somatic pain.
Visceral pain: is usually caused by ischemia (low blood flow) and inflammation. Examples include appendicitis, ovarian torsion, and cardiac disease. It is diffuse and difficult to precisely locate and describe (“sick feeling,” “deep,” or “dull”). Visceral pain may actually present as referred pain to a more superficial location. Associated symptoms may include nausea and vomiting.
Deep somatic pain: occurs due to stimulation of the nociceptors in bones, tendons, ligaments, blood vessels, fasciae, and muscles (sprains and broken bones). It is also very difficult to localize and usually described as “dull” or “aching.”
Superficial somatic pain: occurs due to stimulation of nociceptors in the skin and superficial tissue (cuts or bruises). It is a sharp pain that is easy to locate and describe.
Neuropathic pain is usually caused by disorders of the peripheral or central nervous system. It may present with dysesthesia (unpleasant perception of sensory stimuli), or allodynia (pain due to stimuli not normally considered painful), hyperalgesia (intense response to a stimulus usually considered less painful), and paresthesias (pins and needle sensation). Neuropathic pain may be continuous or episodic in nature. It commonly presents as coldness, “pins and needles,” numbing, or itching. Several common diseases may manifest neuropathic pain, including diabetes, multiple sclerosis, postsurgical patients, certain types of strokes, herpes zoster, HIV, nutritional deficiencies, malignancies, and fibromyalgia.
Phantom pain is a type of neuropathic pain caused by the loss of a part of the body that is no longer supplying sensory input to the brain. It is common in amputees (82% in upper limb; 54% in lower limb). 3 It is reported in 72% of patients within 1 week of amputation and in 65% of patients 6 months postamputation. 4,5 The pain may be such that even touching these patients with a blanket or strap evokes a pain response powerful enough to result in urination or defecation.
Psychogenic pain is caused by emotional, mental, or behavioral factors. It can be quite intense, and/or prolonged. It is also called psychalgia or somatoform pain. These patients are often “labeled” as hypochondriacs with fictitious pain. However, pain specialists consider this pain no less “real” or painful than other types of pain.
EPIDEMIOLOGY OF PAIN
Pain is the primary reason for emergency department visits (>50%) and becomes more common as a person ages. 6 However, there is no simple relationship between gender or age and pain.
Pain in children was often ignored, with surgery and other procedures routinely performed on these patients because it was felt that pediatric patients had “immature” nervous systems that did not appreciate pain. Research on pain in children is still scarce. However, it is known that chronic pain syndromes in children are usually relapsing and remitting rather than the continuous pain often experienced by adults. 7
Studies have shown that women are less likely than men to receive morphine analgesia for isolated extremity injuries. A similar study found that nurses are less likely to give analgesics to women than to men given identical clinical scenarios. A paramedic study showed no difference in the rate of paramedic-initiated analgesia, but there was a difference in the type of analgesia administered.
Multiples studies have shown that patients of lower socioeconomic status and minorities tend to receive less analgesia for their pain. A retrospective review of 953 patients receiving pain medication for lower extremity injuries found a clear trend in which each successively lower income group had a reduced likelihood of receiving analgesia. While this was not a statistically significant finding, the trend was pervasive and deserves further inquiry. Other studies have found that minorities also have their pain levels underestimated. A growing body of research reveals that there are extensive gaps in pain assessment and treatment among racial and ethnic populations, with minorities receiving less care for pain than non-Hispanic Caucasians
There are many types of pain associated with this group. The most common are headaches, chest pain, and back pain.
Headaches: This is the most common type of pain among all age groups. Tension headaches are by far the most common type (lifetime prevalence of 80%) and are more common in women and younger adults. 7
Chest pain: Chest pain is the sine qua non of acute coronary syndrome (ACS). However, there is marked variability in pain intensity as well as other symptoms with ACS. Studies have shown that pain intensity peaks prior to hospital admission and many pain treatment strategies have been devised, including the use of nitrates, narcotics, β-blockers, and benzodiazepines. In the prehospital setting, there is currently not an optimal use, or combination of use, for these four most common therapies for ACS chest pain. There is also not much known about the impact that early and complete relief of chest pain has on the early phase of ACS, and few studies comparing pain-relieving strategies in the prehospital phase of ACS. However, Zedigh and colleagues found that prehospital interventions to decrease in chest pain within the first 30 minutes decreased heart rate and ST-segment elevations without decrements in systolic blood pressure or evidence of ST-segment depression.
Back pain: This is another common type of pain, one that is associated with many factors (physical, psychological, and social). It usually begins in the late teens to early forties, and plateaus in fifth decade of life, with an increased prevalence in those who smoke.7
Pain in geriatric patients: The most common pain in this group of patients is joint pain. The prevalence of hip and knee pain in those over 65 years of age is more than double that of younger adults. 7 The literature shows that both prehospital and emergency department staff fail to provide timely pain management for the elderly with femoral neck fractures. In these patients, communication issues and cognitive impairment comprise the majority of reported barriers to providing analgesia.
Pain in cancer patients: Cancer pain is caused by a variety of mechanisms and may involve the viscera, bone, or nerves. Patients with cancer experience greater pain in the later stages of their disease, and the treatment of their cancer may actually exacerbate their cancer pain. 7 There is significant evidence that the pain these patients experience is undertreated. The cancers cited most often as being associated with significant pain are bone, cervix, oral cavity, stomach, lung, genitourinary, pancreas, and breast.7
Pain in immunodeficient patients: Pain is a major problem for those with AIDs, especially in the later stages of the disease, and is comparable in intensity to that of cancer patients.7 The incidence of pain in those with HIV is approximately 30%.7 There is some gender and social bias in the treatment of these patients. In particular, women, less educated patients, and drug abusers are often undertreated.7
IMPORTANCE OF EARLY PAIN CONTROL
There are many reasons to treat pain adequately. Failure to do so may make it more difficult to treat future pain, increase the likelihood of developing chronic pain, and may lead to changes to a patient’s behavior in response to future pain. Inadequate pain control may lead to an increased pain threshold, making it more difficult to treat subsequent episodes of pain.
There is a “wind-up phenomenon” that causes untreated pain to worsen. Nerve fibers become more adept at delivering pain signals to the brain. The intensity of the signals increases over and above what is needed to warrant attention. The brain becomes more sensitive to the pain. Thus, pain feels much intense even though the injury or illness is not worsening. Early analgesia minimizes this phenomenon.
Preemptive analgesia or preventive analgesia is an evolving clinical concept. It involves the introduction of an analgesic regimen immediately upon recognition of pain or before the onset of noxious stimuli (ie, a planned procedure), with the goal of preventing sensitization of the nervous system to subsequent stimuli that could amplify pain. The importance of preemptive analgesia is that untreated acute pain has the potential to produce acute neurohumoral changes, neuronal remodeling, and long-lasting psychological and emotional distress, leading to a prolonged chronic pain states. Treatment should encompass the entire duration of the high-intensity noxious stimulation that can lead to establishment of central and peripheral sensitization caused by an injury.
It is not surprising that patient satisfaction is higher when pain control is offered. Patients given analgesia are often “uptriaged” upon arrival to the emergency department, due to the perception that the patient’s presentation is of a higher acuity. Conversely, patients not given analgesics in a prehospital setting are more likely to have a significant delay in receiving analgesics in the emergency department.
THE GOALS OF PREHOSPITAL PAIN MANAGEMENT, ANALGESIA, AND SEDATION
Success in patient treatment and therapies depends on the strength of the plan. All protocols should be developed, and reviewed with regularity, by a multidisciplinary team. This team should comprise paramedics, EMS supervisors, nurses, and physicians (medical control physicians, trauma surgeons, and emergency medicine specialists). The basic tenets of the plan should address these issues.
Unanimous advocacy from leadership that patients should receive expeditious pain management
Succinct, simple strategies and protocols that optimize pain assessment in all patients and require pain management intervention and recording of intervention following each assessment.
EMS systems should develop policies and procedures for the safe utilization of pain medications
BARRIERS TO THE ADMINISTRATION OF PREHOSPITAL ANALGESIA
Paramount to the care of patients is to abide by the health care professional’s responsibility to accept the patient’s report of pain and to respond in a positive manner.8 The development of any successful analgesia and sedation protocol must identify barriers to such care and develop protocols that mitigate these barriers.
The inability to assess pain is challenging. Hennes and colleagues found this to be the most common barrier, with paramedics listing it as their primary barrier in treating 87% of their pediatric patients and 90% of the adults. The use of pain assessments was dismally low for adolescents (5%) and children (2%) in the Hennes study. Several studies have confirmed the lack of pain assessment in pediatric patients. While 93% of prehospital providers had knowledge of adult analgesia indications for extremity fractures, only 50% thought that analgesia was needed for children with these injuries. These statistics were similar for adults and children with burns. Moreover, medical control leadership in the mandatory use of pain assessments for all patients has been clearly shown to improve compliance with the administration of analgesia and has been advocated in the NAEMSP position paper.
All pain concerns should be addressed. Some providers equate low pain scores as an indication not to medicate. Situational or experiential factors also come into play. Some providers believe they can ferret out true pain from “false” pain based on patient behavior, communication, and the interpretation of physical and hemodynamic parameters. Below are factors providers may use to gauge the need for analgesia.
Patient behavior and cooperation: Observation of the patient’s behavior and level of cooperation is used as an indicator for pain.
Nonverbal communication: Signs such as facial expressions, guarding, and withdrawing from examination were also seen as important.
Physical signs: Signs such as diaphoresis, swelling, deformity, or abnormalities in vital signs are also seen as important. Some paramedics question the patient’s pain claim if their physical examination and vital signs do not correspond.
Difficult vascular access is a known barrier to analgesic administration. One study found this reason cited as a barrier to the administration of morphine analgesia in 80% of both their adult and pediatric patients. These same providers cited “vascular access not required” as a barrier in 67% of both their adult and pediatric patients. Often providers find it easier to simply transport these patients and allow the emergency staff to obtain access and address painful conditions. However, delaying analgesia or sedation to a patient until arrival to the hospital only delays care. Other routes of analgesics administration should be considered such as oral, intranasal, intramuscular, or interosseus routes. A retrospective review of the time to analgesia for patients with painful extremity injuries found that only 12% received prehospital analgesia (average time 23 minutes). The other 88% received their first parenteral analgesia in the emergency department (113 minutes later). These results mirror a similar study of lower extremity fractures in which the mean time for the EMS treated group was 28 minutes versus 146 minutes for the ED treated group. Clearly, delaying pain management until arrival to the ED is not an optimum strategy.
Prehospital providers undertake an inordinate amount of tasks, even during routine transports. Record keeping, application of monitors, the obtaining of intravenous access, continual patient assessments, and reports to medical control/hospital of destination are just some of these. Paramedics also have to explain treatments and treatment options, obtain histories, allergies, medications, and engage in specific care such as splinting, hemorrhage control, elevation, and wound care. It is not surprising that the barrier of “other care adequate” and “record keeping” receive mention as significant barriers to analgesia and sedation. However, as previously stated, pain is the most common reason for patients to seek emergency care. Mandatory pain assessments with expected provider actions should be part of the quality assurance studies of EMS organizations.
The perception of drug seeking behavior may significantly reduce administration of analgesic medications. In the Hennes study, 81% of paramedics listed drug seeking as their reasoning for withholding analgesia. More impressively, these same paramedics (65%) also voiced drug seeking as a reason to withhold pain medications in children.
Providers’ personal bias may play a role in their perception of a patient’s pain and subsequently affect the overall administration of an analgesic. One study queried paramedics as to how they recognize pain. The overall response was that there is no classic sign and that experience was their guide.9 Overall, the majority of the paramedics in this study do not perceive all patients to be honest and feel that some exaggerate their pain.9 Some paramedics consider the “on a Scale of 1 to 10” to be too subjective to utilize as an indicator for analgesic medications. Others felt this overexaggerated behavior was a justification for calling an ambulance or to be seen quicker.9 Additionally, 83% of providers considered the cultural background of the patient to have a major impact on the patient’s pain experience. Some cultures are thought to be more vocal and emotional in expressing their pain.
A paramedic’s perception of the patient’s pain determines the treatment that is rendered. A provider’s belief that they can objectively determine a patient’s pain level and treat accordingly (withhold or provide analgesia or sedation) is false.10 Medical care providers, prehospital or otherwise, cannot see, feel, or define the pain that is experienced by a patient. Caregivers, prehospital providers, and others have been shown to underestimate patient pain levels. In the Hennes study, 37% of paramedics thought they administered morphine to adults with chest pain (actual number 4%); 24% reported giving morphine for extremity fractures (actual 12%); and 89% thought they gave morphine for burns (actual 14%). Now this may be related to the provider’s desire to meet establish goals on self-surveys. However, disparities such as these are concerning, and require further investigation.
This is a concern for many paramedics, and some would rather not treat a patient’s pain if they consider the pain to be a crucial element in diagnosis.9 Pain and its resultant anxiety are counterproductive to diagnostic and therapeutic interventions. Uninterrupted pain also adversely affects immune function, wound healing, and is associated with diagnosis-specific adverse events, such as blood pressure elevations in head-injured patients. Early studies and texts created a concern that analgesic administration blunts accurate examinations and delays or obscures diagnosis (eg, acute abdominal conditions). This is incorrect. Severe pain precludes proper examination. Diagnostic tenderness is usually not affected by analgesia. Early pain management allows better cooperation and facilitates examination, and several studies have demonstrated that it is a safe practice to administer opioids in patients suspected to harbor critical illness.
There is a certain degree of reluctance on the part of patients to complain of pain or to ask for pain medication. McEachin found that two-thirds of patients were not aware that EMS providers could give analgesics. The remaining third did not ask for analgesia despite knowledge of the availability of these medications. The same study found that 93% felt that their pain was poorly assessed and 66% felt their pain was not well managed. EMS providers should take the lead in advocating for early pain management for their patients. Pain assessment scales could guide the EMS provider in the appropriateness of analgesia.
Paramedics consider the types of illnesses (limb trauma, cardiac pain, back pain, labor, abdominal pain, sickle cell crises, and fractures), travelling time, nature of the roads, and hospital delays in their decision-making process.9
The type of injury or illness also influences a paramedic’s decision to withhold pain treatment. The paramedic’s perception of patient honesty is a key factor. Additionally, some paramedics feel that they can psychologically help patients control pain. They feel it is essential to take control of the situation, relieve anxiety, and gain the patient’s trust. For these providers, it is considered possible to “talk the patient down through their pain and reduce their pain without the need for drugs.”9
Pain is a complex, multidimensional experience determined not only by the injury severity, but also by previous pain experience, personal beliefs, motivations, and environmental factors. There is no objective measurement of pain. Self-reporting is the most valid. Caregivers cannot perceive the pain experienced by their patients, therefore, they must rely on self-reports, pain assessment scales, verbal and nonverbal communication, injury mechanisms, previous experiences, and empathy. Reports of pain may not correlate with the observed disability or physical examination findings. Pain assessment scales are important in providing a quantitative assessment of the pain as well as response to interventions. In spite of their repeated validation as an important tool that improves patient care, pain scales continue to be underutilized. Pain scales aid in real-time assessment and the care of patients and are vital for quality improvement that allows real time analyses of efficacy of interventions or changes in practice patterns.
The VAS is one of the most commonly used pain measurement tools. It consists of a 10-cm slide ruler device that is bounded on each end by perpendicular marks and descriptors. Patients are asked to move the slide rule along the scale to indicate the severity of their pain. The VAS has been shown valid for research purposes as well as a reliable measure of pain severity (Figure 62-1).
The NRS is a rapid and simple pain severity tool, in which patients are asked to rate their pain on a scale of 0 to 10. The advantages of this scale lies in its simplicity, reproducibility, easy comprehensibility, and sensitivity to small changes in pain. Patients prefer the NRS to the VAS. The NRS can be administered verbally without requiring cognitive translation into a mark on a 10-cm scale (Figure 62-2).
Wong-Baker FACES can measure pain in infants and young children using self-report scales or scales using physiological and behavioral measurement. Caregivers and parents tend to underestimate the severity of pain in pediatric patients. Pain scales for pediatric patients need to be tailored to the patient’s stage of development. In infants, pain assessment is inferred by behavioral responses (crying and facial grimacing) and physiological parameters (vital signs). In toddlers and young children, pictorial pain scales such as Wong-Baker FACES are useful. Older children can use NRS, VDS, or perhaps even VAS to assess their pain (Figure 62-3).
Wong-Baker FACES pain scale (Wong-Baker FACES Foundation (2015). Wong-Baker FACES® Pain Rating Scale. Retrieved [Date] with permission from www.WongBakerFACES.org.)