As recently as 15 years ago, the approach to pain management was a symptomatic one, whereby the symptom of pain was hidden or minimized with a general analgesic such as an opioid or acetaminophen. Additional pain relief was sought by treating the underlying disease under the assumption that the pain would resolve if you did so.
Explore This IssueACEP Now: Vol 34 – No 02 – February 2015
The symptomatic approach has been almost completely replaced by a mechanistic approach. With this approach, the neurobiological mechanism creating the pain is identified and neutralized with a targeted medication. Although far more applicable in managing chronic pain, the mechanistic approach was first seen in acute pain settings. Witness the change from opioids to dopamine antagonists (eg, chlorpromazine, prochlorperazine, metoclopramide) and serotonin agonists (eg, triptans, ergotamines) for migraine and other vascular headaches. The role of prostaglandins in smooth muscle tension has resulted in the use of nonsteroidal anti-inflammatory drugs (NSAIDs) for renal and biliary colic as well as for severe menstrual cramps. Anticholinergic agents can be effective for both intestinal cramps (hyoscine) and large muscle spasms (benztropine). The indications for the primary use of an opioid in emergency medicine have been refined; there are many fewer indications than before, making their use even more justifiable in these specific instances (eg, extremity fractures, visceral pain, vaso-occlusive crisis).
Pain in the ED
In chronic noncancer pain, specific neurotransmitters and nerve channels have been relatively well-established. In neuropathic pain, either a sodium channel (tricyclic) or a calcium channel (gabapentanoid) blocker serves as first-line therapy, with opioids relegated to third- or fourth-line treatment. In diffuse widespread pain such as fibromyalgia, opioids are not recommended at all, with NSAIDs, tricyclics, or gabapentanoids being the optimal choices.
The indications for the primary use of an opioid in emergency medicine have been refined; there are many fewer indications than before, making their use even more justifiable in these specific instances (eg, extremity fractures, visceral pain, vaso-occlusive crisis).
In managing trauma patients, the last few years have demonstrated that the addition of low-dose (analgesic dose) ketamine serves to decrease the dosing requirements of opioids to control pain. It also serves to block N-methyl-D-aspartate (NMDA) release, thereby decreasing wind-up (pain after discharge and the risk of development of chronic pain). For procedural analgesia, ketamine and nitrous oxide serve as excellent alternatives to opioids. Ketamine, in an analgesic dose (0.2–0.3 mg/kg), seems to lead to less oxygen desaturation and hypoventilation when combined with a sedative than when an opioid, such as fentanyl, is used. The use of “ketofol,” a combination of ketamine and propofol in the same syringe, seems to offer no added value over giving a single dose of ketamine followed by the titration of an ultrashort-acting sedative such as propofol or methohexital.
Nitrous oxide was widely available in emergency departments 20 to 30 years ago in North America, but it fell out of favor for two reasons: misuse by staff and variable effectiveness in patients. Both of those problems were the result of trying to make use of a 50/50 mixture (nitrous and oxygen). Use of the 70/30 mixture has provided solutions to both problems: the stronger mixture does not lead to euphoria but rather unconsciousness, making it rather evident who might be trying to misuse it! Analgesic effectiveness is almost 100 percent with the 70/30 mixture, and it is widely used in Australia as a result. It is almost omnipresent in Canadian pediatric EDs as well. Current regulations already in place in the United States for other procedural sedation medications should allow a relatively easy process to reintroduce nitrous oxide into emergency departments. Indications for nitrous oxide’s use rapidly come to mind because of its rapid-on, rapid-off effect. They include catheter placement in cognitively impaired children, casting a pain fracture, and disimpaction, to name a few.
In Europe, where experience now exceeds three years, IV acetaminophen is used routinely in acute pain management as part of a multi-medication approach.
The introduction of IV acetaminophen in the past two years has provided yet another option for acute pain management. In studies to date, 1 g IV of acetaminophen appears to have an analgesic impact almost equivalent to 10 mg morphine. Of course, the same was also said of ketorolac when it was introduced to the market. In Europe, where experience now exceeds three years, IV acetaminophen is used routinely in acute pain management as part of a multi-medication approach. Start with acetaminophen except in obvious severe pain (polytrauma, fractures, etc.) and add an opioid if required. Even in patients requiring opioids, acetaminophen is used, if only to minimize initial dosing of all medications, thus minimizing adverse events from any one agent. Evidence about the safety of repetitive doses of IV acetaminophen does not yet exist. Evidence suggests that 2 g by mouth as a one-time dose would probably be just as effective.
The use of regional anesthesia will be discussed in a future article because it, too, can play an important role in pain management of fractures and in procedures.
Concern over opioid misuse is at its highest when discharge prescriptions are written. First consideration should be to avoid prescribing the opioid most misused in your community. Each community chooses its opioid. Within a 60-mile radius of where I have worked, patients have told me that “only idiots” abuse any opioid other than “fill in the blank.” Heroin, oxycodone, meperidine, hydromorphone, fentanyl, dextromethorphan—they all have been abused, but usually only one is abused in any given community. This is primarily due to control of the drug scene by one gang or another. If opioids do have to be prescribed, limit dosing to three to four days maximum because follow-up for persistent pain is essential.
Newer options that have been promoted include tapendtatol and tramadol. The former has turned out to be a very poor analgesic that costs a lot of money, whereas the latter has not gained much favor in the emergency physician community. Neither is at risk for abuse, and tramadol does offer valid analgesia in many patients. It might be of value to provide it in the ED to see how helpful it is prior to writing a prescription for it.
The NSAID with the best analgesia/anti-inflammatory/safety profile still is ibuprofen. It is the recommended analgesic of choice for dental pain. For new onset or a flare of chronic sciatica or other neuropathic pain, short-acting opioids will rarely help the patient. A combination of a NSAID with a tricyclic (nortriptyline is less sedating) is probably best. It is important to note that the starting dose of the tricyclic should be 25 mg at bedtime, rapidly titrated over seven to 10 days to at least 75 mg and with follow-up with a primary care provider. Carbamazepine for tic douloureux should be started at 200 mg and titrated up 200 mg every three days to effect, again with follow-up within one week. Initiation of either a tricyclic or a gabapentanoid (gabapentin 300 mg, increasing by 300 mg every three days to effect, or pregabalin 25 mg a day with much slower ramp up due to side effects) for postherpetic neuralgia (PHN) is an excellent option. See Table 1 for more recommendations for treating neuropathic pain.
Many nonopioid options exist, but to use these medications optimally and safely, a much greater understanding of pain mechanisms is required. Opioids have their place but a much smaller one than what was seen in the nondiscriminate symptomatic approach era.
Dr. Ducharme is editor in chief of the Canadian Journal of Emergency Medicine and clinical professor of medicine at McMaster University in Hamilton, Ontario.
Brief Script of How to Say No to the Opioid-Seeking Patient
Here are two variations of a script I use routinely. It is always essential to get two points across to patients:
- You are willing to help them manage their pain.
- You know the rules of the game.
Using variants of the below, I can count on one hand the number of times in the past five years the situation degenerated to where the patient was swearing or yelling.
Note that I also assess the patient to ensure there is no new pathology (especially in cancer patients) or acute flare-up of a chronic pain (complex regional pain syndrome and arthritis often have severe flares). These groups do require aggressive pain management in the ED and may well require opioids, but the patients do not get a new prescription unless this is true or unless I discuss the situation with the prescribing doctor, who then agrees.
You can also gently say you will check the state drug database to ensure they are receiving their medications solely from their prescribing doctor. In Canada, that makes drug misusers run for the door because false reporting of a controlled Rx is a felony, and as an emergency physician, I am required to call the police if I am aware of a false report and the patient is in the ED—and the patients all know this as well!
The Patient Encounter
Hello, Mr./Ms. X.
I am Dr. Y. How can I help you today?
Patient states need for opioid prescription.
OPTION 1: Mr./Ms. X, I am here to help you in any way I can and to see what exactly might be wrong. With respect to your request for me to renew your prescription of opioid Z, I am unable to do so. We are aware that doctors who prescribe opioids for long-term use advise their patients that only they can prescribe additional opioids. You would have had to agree to that before your doctor would have started that prescription. Even if you need more pills because of worsening pain and have run out early, you still need to see the doctor who prescribes those medications. Knowing that I am unable to renew that prescription, how else can I help you control your pain today?
OPTION 2: Mr./Ms. X, you say that you have run out of your pain pills and your doctor is away. As you know, you have to be responsible and accountable for your medications. If you saw that you were running low, it was up to you to contact your doctor and discuss obtaining more medications. I do know that most doctors caring for people in pain will not allow early renewals of their medications. They also request, and get their patients to agree, that only they can prescribe these pain medications. You certainly had that discussion with your doctor. So you can understand that while I am very willing to see how I can help better control your pain today, I cannot prescribe the additional pain pills that you are requesting. How else can I help you?