Abstract
This is an overview of pain management and conscious sedation in the Emergency Department. Suggestions for the approach to chronic pain in the emergency setting are made. Finally there are also suggestions for procedural conscious sedation.
Keywords
conscious sedation in the emergency department, pain management in the emergency department
The complaint of pain is the most common symptom presenting to the Emergency Department (ED). Over the past 15 years, the Joint Commission has emphasized the recognition of pain, and it now considers pain the fifth vital sign. The causes of pain encompass the entire range of human diseases, including psychological illness. The assessment of the severity of pain is subjective, and what appears to be the same problem or injury can affect each individual very differently. Several systems have been developed to quantify the degree of pain, but all rely on the patient’s perception of their pain. Practitioners must use all their clinical acumen to make an appropriate decision regarding the need for and class of analgesic to use in a given circumstance.
Pain can be divided into two major categories, acute and chronic. Acute pain serves a physiologic function in that it is a warning to the patient that something is wrong and results in the patient seeking help or prevents the patient from doing further harm by limiting activity. The bulk of this chapter is devoted to the discussion of the management of acute pain in the ED. The transition point from acute to chronic pain has been variably defined, ranging from as little as 4 to 6 weeks up to 6 months of pain.
Chronic Pain
Chronic pain serves no useful function to the patient. Patients with chronic pain can be divided into four general groups. These groups are patients with chronic pain secondary to underlying diseases, such as cancer, sickle cell disease, and AIDS; patients with known pain syndromes, such as tic douloureux and migraine headache; chronic pain patients without an identifiable cause; and finally, the group of patients that uses the complaint of chronic pain to obtain drugs or for other personal gains.
Each of these groups of patients requires a different management approach. Cancer patients with new pain or with acute worsening of their previous pain should be evaluated for a new complication, and their pain should be aggressively managed with opiates. For these patients, palliative screening can be initiated in the ED and can be very helpful for their long-term management. Patients with known pain syndromes and without objective cause for their pain require an aggressive team approach, and if they are patients within your institution, prearranged therapeutic plans should be in place for when they appear in the ED. This is particularly helpful for those patients with sickle cell disease and frequent pain crises. The final group is a subset of pain patients that tests the patience and professionalism of emergency physicians and nurses. The majority of these patients are seeking narcotics. The diagnosis of malingering must be a diagnosis of exclusion and cannot be made on the first visit by a patient to the ED. An appropriate workup for the patient’s complaint should be done and often needs to be repeated 2 or 3 times before the diagnosis of malingering is made. If malingering is suspected, the patient should be referred to the outpatient pain and psychiatric services for further evaluation and treatment. Each time these patients appear in the ED, the emergency physician should perform at least a basic history and physical examination, but you can refuse to give further narcotics. Nonsteroidal antiinflammatory drugs (NSAIDs) may be offered, but these patients will often refuse them or state that they cannot take them. There are no hard and fast rules as to how to handle this type of patient. All you can do is maintain your professional ethics and practice and do the best you can by performing an adequate assessment and then refer the patient to the appropriate outpatient services.
Acute Pain
Pain is a combination of physical, chemical, and psychological factors. There is no current method to directly measure the degree of pain that a given patient is experiencing from a given injury. However, if a patient presents to the ED with a complaint of pain, an attempt should be made to quantify the patient’s perception of the degree of pain. A patient’s verbal report is the only way to reliably obtain a patient’s evaluation of their pain. Several tools have been developed to grade a given patient’s pain and the response to treatment ( Table 36.1 ). Pain scales should be incorporated as part of the triage process and should be located on the record where the vitals are recorded. The severity of pain index should be recorded during the initial assessment process, and early and effective management of pain should be ensured. After treatment, the assessment should be repeated as needed. However, all too often, this does not occur.
| Clinical Tool | Grading Pain | When Used |
|---|---|---|
| Verbal quantitative scale | 0–10 (None to worst possible) | Routine evaluation |
| Visual analog device | [____________]. None to worst. Patient places a mark on the line. | Routine evaluation |
| Global satisfaction question | Are you satisfied with your pain relief? Yes/No | Useful for confusing patients |
| Pediatric pain scales | ||
| Observer generated | Facial expressions, crying | Neonate to age 3 and some 3–6 |
| Draw a picture of your pain | Est. location, intensity, and character | Over age 6 and some 3–6 |
| Faces | Over age 6 and some 3–6 | |
| Pain thermometer | Like visual scale for adults | Over age 6 and some 3–6 |
There are several difficult to control barriers to the successful management of acute pain in the ED. These include overcrowding, age, ethnicity, and overall attitude of the caregivers. In addition, the emergency physician must focus on diagnosis of the cause of pain which may distract from the management of the pain itself. Numerous studies have documented inadequate use of analgesic agents in the ED. This is particularly true in the pediatric population. Many patients do not receive any pain medications while in the ED, even though their primary presenting complaint was pain. In addition to no analgesia, there are a number of therapeutic errors that may result in the inadequate use of analgesics in the ED. These include prescribing the wrong agent, inappropriate dosage and dosing intervals, route of administration, improper use of adjunct agents, and concern for medically induced addiction to narcotics.
Failure to give analgesics is an issue that must be addressed by education of nursing staff and physicians. The goal should be adequate pain relief for all patients. Emphasis of the importance of pain control to the patient is key in this process of changing practice habits. Patient satisfaction may be directly related to adequate pain control. In addition, the early control of acute pain appears to reduce the incidence of chronic pain syndromes and may improve the patient’s outcome. Finally, health care providers have taken an oath to reduce or prevent pain and suffering.
Correction of the inappropriate usage of analgesics also requires a great deal of physician reeducation, and frequently, major changes in practice habits must be instituted. Severe pain generally requires the use of parenteral opioids. In the acute situation, an intravenous (IV) line should be established, and the dosage titrated for the individual patient. The amount required of a given opiate for adequate pain relief can vary widely from patient to patient. For example, the effective level for morphine has been reported to be as much as 8 times greater from one patient to another. The intramuscular (IM) route should be avoided, as it is painful and the onset of action is variable. If an IV cannot be obtained, the subcutaneous route offers an excellent alternative. In addition, there are newer agents that can be given by the sublingual or nasal route. Fentanyl is available in sucker form, which has great applicability in the pediatric population. Sufentanil and butorphanol, both potent opioids, are effective when given via the nasal mucosa. Once the route and dosage is determined, it should be given at frequent enough intervals to prevent the return of pain.
There is little role for adjunct agents in the management of acute pain in the ED. The exception is the clinical circumstance of persistent nausea and vomiting following the use of opioids or in patients with pain who also have nausea and vomiting. The practice of using an adjunct to reduce the opioid dose simply is not valid and exposes the patient to another set of side effects. This practice should be abandoned.
The risk of addiction to the opioids with medical use must be a concern for physicians, especially when treating patients with chronic pain. However, in the acute patient, there seems to be little evidence for undue concern. Of 11,892 inpatients who received opioids while in the hospital, only 4 became addicted without a prior history of substance abuse.
Specific Problems
Abdominal Pain
For years, the conventional teaching was to avoid the use of opioids for abdominal pain until a definitive decision had been made regarding surgery. This was sound and necessary practice prior to the development of modern diagnostic tools, such as computed tomography (CT) scanning. Simply put, this practice is outdated. From the published literature on this subject, there has not been a significant increase in management errors demonstrated nor is there evidence for major morbidity or mortality associated with the early use of opiates in the treatment of abdominal pain. The goal in patients with abdominal pain is not to achieve pain free status, but rather to substantially reduce the severity of the pain. Opioids given by the IV route allow for careful titration of these agents. The patient should be kept responsive enough to allow for subsequent examinations. Close observation of the patient’s course is mandatory, especially in patients with ulcerative colitis because of the added risk of toxic megacolon. NSAIDs can be effective therapy when treating biliary or renal colic.
Headache
The complaint of headache is commonly seen in the ED. Many of these patients have a known history of a specific type of headache such as migraine or vascular headaches. There are many causes of headache, and a minority of these patients may require extensive workups, including CT scanning, MRI, and lumbar puncture (LP), to exclude a life-threatening cause of headache. By far the majority of patients presenting to the ED with the complaint of headache will need only pain relief and follow-up. A useful reference to assist the emergency physician to sort through this complaint is the Classification and Diagnostic Criteria for Headache Disorders, Second edition, published by The International Headache Society in 2004. This handbook provides an organized approach to the diagnosis and management of the various types of headache and facial pain.
Migraine
In the United States, over 1 million patients per year present to EDs with the complaint of migraine. If the patient does not have a clear and reproducible history of migraines, this diagnosis should be made with caution, and a headache workup needs to be done. If the prodromal symptoms, pattern of pain, and associated symptoms are similar to past attacks, the workup may be limited to a history and physical exam unless there is coexisting illness. Most of these patients have had failure of their usual medications to control pain prior to arrival to the ED. Therapy to relieve the pain is indicated. In mild to moderate migraine, acetaminophen or nonsteroidal agents are often effective. In more severe and persistent migraine, such agents as sumatriptan given subcutaneously or by nasal spray, prochlorperazine, and metoclopromide by the IV route may be required to both relieve the pain and to counteract nausea and vomiting. Sumatriptan works best if used early in the onset of a migraine. This agent is contraindicated in patients with known coronary artery disease, hypertension, pregnancy, and peripheral vascular disease. The other two agents may be associated with hypotension, sedation, and dystonic reactions, and an anticholinergic drug should be added if these agents are given in high doses. Patients receiving metoclopromide or similar agents should receive a 500 cc bolus of saline prior to the drug being given to help avoid hypotension. When added to standard acute migraine therapy, 10 mg of dexamethasone given IM or IV appears to reduce the incidence of recurrent migraine over the next 24–72 hours. Opioids should only be given for patients who do not get relief by other means or in those who are unable to receive other agents. Dihydroergotamine is contraindicated in vascular disease, in the elderly, and in patients on monoamine oxidase (MAO) inhibitors or if sumatriptan has already been used. This agent is especially useful for those patients with a refractory attack of migraine, and if used, the patient should first receive an antiemetic.
Cluster Headache
Cluster headaches are seen much less commonly in the ED, and emergency physicians are often less comfortable with management of this clinical problem. If the patient is having a typical pattern of headache, there is little indication for extensive workup, and treatment should be initiated to control the pain. In many cases, sumatriptan will abort the attack. Frequently the patient with this problem has already used this medication, and needs pain control. High flow oxygen will often end the attack. If these attempts fail, dihydroergotamine given by the IV route is effective. Numerous other agents have been used, but if the above fails, neurological consultation should be considered to assist in managing this problem.
Subarachnoid Hemorrhage
Subarachnoid hemorrhage (SAH) remains a difficult diagnosis for the emergency physician, and SAH has a high morbidity and mortality rate, exceeding 50%. Many of these patients will expire before they can get to medical care or arrive at the ED comatose. Patients with SAH often deteriorate rapidly, and early diagnosis is mandatory to maximize the chances for a good outcome.
The speed of onset of the headache is a major diagnostic clue. If the headache has come on over more than a few minutes, it is highly unlikely that the headache is due to an SAH. In many cases, the patient describes the headache as if their head is exploding or that the top of their head felt as if it was going to come off. These patients will frequently state that this is or was the worst headache of their life, but this complaint is not exclusive to SAH. Even if the patient has none of the other features of an SAH, such as meningismus and neurological findings, these complaints should not be ignored.
A patient giving this type of history should be seriously considered for the work-up of SAH. The approach for many years has been to obtain a rapid CT of the brain to look for blood, and if this is negative, an LP should be used. CT cannot be relied on alone, as up to 10% of acute SAH does not show blood on CT. This percentage is based on results from the earlier generations of CT scanners, and it is probably much less today. If a cranial CT is performed closer to the time of onset of the headache associated with SAH, then the cranial CT is more reliable. By 1 week after an SAH, the percentage of false negatives on a brain CT may exceed 50%. A diagnostic alternative to an LP is a CT angiogram that is widely available today and is almost as reliable as LP to detect bleeding and diagnose for aneurysms.
Pain relief can be given. Nonsteroidals are contraindicated in the treatment of patients with suspected SAH because of their anticoagulation properties. Treatment similar to that for migraines as described above is often effective and should be tried first. If the headache is rapidly relieved by these agents, it is unlikely that the patient has SAH. Opioids are safe and effective, but it should be titrated to prevent excessive sedation.
Tension Headache
This is the most common cause of headache in the ED and is frequently associated with other medical and psychological problems. Tension headaches are also the most general and difficult to categorize. To a great extent, this is a diagnosis of exclusion and should only be given if the practitioner is satisfied that a more serious problem is not causing the headache. This may require imaging studies. Tension headaches often have a general pattern in that the patient complains of a bandlike pressure around the head and associated neck stiffness. Other symptoms are usually absent, and, if present, they are mild. Pain relief can usually be achieved with acetaminophen or nonsteroidals. If there is associated anxiety, mild tranquilizers may help to prevent recurrence.
Other Causes of Headache
There are numerous other disease processes that either are the direct cause of or are associated with the complaint of headache. An in-depth discussion of these is beyond the scope of this chapter. In many of these conditions, associated neurological symptoms will make the complaint of headache secondary. If the headache is related to a space-occupying lesion in the brain, opioids in careful doses are very useful to relieve the patient’s suffering. The patient requires rapid consultation with the appropriate specialty. For headaches associated with underlying medical diseases, such as hypertension, the treatment of the underlying problem will often relieve the headache with minimum need for analgesia. Suffice it to say, the emergency physician must use judgment when prescribing pain medications for the headache patient. Underlying causes for the headache should not be masked by the aggressive use of analgesics. However, the patient should not be denied some relief of their discomfort. Careful selection of the agent used, appropriate titration of the dosage of the agent, and proper delivery route of the drug can go a long way towards achieving these therapeutic goals without overly confusing the clinical picture.
Chest Pain
Chest pain is a frequent complaint in the ED. The causes of chest pain are myriad, and the emergency physician must make rapid clinical decisions if the pain is secondary to a life-threatening disease. The three most common serious diseases presenting with chest pain are myocardial ischemia and infarction, pulmonary embolism, and dissection of the thoracic aorta. Clinical pathways, particularly for myocardial ischemia, are well established. Part of these pathways is the use of morphine for the reduction of pain and anxiety. A major role of this agent is in those patients whose pain is not fully relieved by nitrates and beta-blockers. Doses should be given IV and titrated to achieve pain relief without respiratory depression. The clinician must carefully monitor the patient to avoid hypotension. Aortic dissection commonly requires an opioid to relieve the severe pain experienced by patients with this condition. Pulmonary embolism seldom requires heavy analgesia, and good pain relief can usually be obtained with NSAIDs. If required, opioids are safe and effective.
Most of the remaining causes of chest pain are either inflammatory, such as pericarditis, or due to musculoskeletal problems. The majority of these patients will respond well to NSAIDs or to acetaminophen. Adjunct therapy of heat or cold, massage therapy, and physical therapy may be indicated in follow up. A commonly occurring condition where NSAIDs should be avoided is in those patients with gastroesophageal reflux disorder (GERD). Acetaminophen may be used, but primary treatment with antacids and histamine blockers should be initiated.
Musculoskeletal Pain
All people experience a variety of aches and pains secondary to contusions, minor arthritis, and soft tissue sprains and strains. By far, the majority of these individuals treat themselves at home with a host of over-the-counter medications of varying degrees of efficacy and other adjunctive measures. The two over-the-counter drugs most frequently used today are ibuprofen and acetaminophen. If these patients present to the ED, a history of what agents and the amount taken needs to be obtained by the emergency physician to give appropriate treatment and to avoid overdosing the patient. Icing sprains and contusions and appropriate splinting and immobilization of the injured extremity is mandated in the acute period, but these adjunct therapies are often overlooked during long waits in the waiting room. This group of patients comprises the largest single source of complaints regarding failure of staff to control pain.
Although there has been little research to support the use of muscle relaxants, they appear to have a role in acute musculoskeletal injury when there is associated severe muscle spasm. Commonly used agents are orphenadrine citrate, methocarbamol, and the benzodiazepines. These agents cannot be a substitute for adequate analgesia. Oral opioids may be required in the management of severe musculoskeletal pain, especially when these patients are discharged. Acetaminophen with codeine has been used for years, but in reality, codeine is a poor analgesic and has not been demonstrated to be more effective than NSAIDs or acetaminophen alone. Other oral opioids are effective in the management of severe pain, but physicians are often reluctant to prescribe them on an outpatient basis because of the fear of causing addiction. Included in this group are hydrocodone, oxycodone, and oral meperidine. These agents should be used if the pain is severe and are generally safe to prescribe for short-term use. All of these agents do have a relatively high potential for abuse, and they should be prescribed with discretion and in limited amounts.
Patients with obvious fractures should be seen as soon as possible, and early immobilization be obtained. This prevents further soft tissue injury and will reduce the pain. Opioids often are required to control the pain, and the safest and most effective method is titration of these agents by the IV route. Patients given IV opioids need to be monitored for respiratory depression, hypotension, and excessive euphoria. If patients require extended “road trips” to radiology for multiple X-rays or CT scanning, they should be accompanied by medical personnel to both monitor their vitals and give additional analgesia if required.
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