Getting out of your comfort zone with opioid-tolerant patients
How do you manage pain in patients already taking high doses of opioids?
Keywords: How physicians in the hospital should manage pain for patients on high-dose opioids
by Bonnie Darves
Published in the April 2013 issue of Today's Hospitalist
AS HOSPITALISTS increasingly comanage patients with specialists and take over postoperatively for surgeons, many find themselves planted squarely in the middle of managing acute pain. And when they treat patients who come into the hospital already opioid-tolerant because of chronic pain or other conditions, hospitalists may quickly find themselves out of their comfort zone.
Dosing can be complicated, especially for patients who have undergone a notoriously pain-inducing surgical procedure or event. But dosing can be tricky even in chronic-pain patients admitted for other reasons, such as gastroenteritis.
Fears about respiratory depression, over-sedation and
potential overdose are absolutely real and "definitely need to be considered," says Nalini Vadivelu, MD, an associate professor of anesthesiology at Yale University in New Haven, Ct.
|"You continue patients' home regimen, then you go above and beyond."|
–Paul Grant, MD
University of Michigan
"However, if you approach dosing systematically and cautiously," says Dr. Vadivelu, co-author of "Essentials of Pain Management" guide, both published in 2011, "you can avoid problems and still ensure adequate pain control." Hospitalists should also consider an approach that may include several adjuvant therapies besides opioids, from antihistamines to muscle relaxants and gabapentin to NSAIDs.
But taking care of opioid-dependent patients postop is challenging, Dr. Vadivelu adds. These patients tend to have a low threshold to pain, often because of opioid tolerance, so under-dosing can be a crisis in the making: out-of-control pain coupled with withdrawal.
Going beyond the total daily dose
To avoid that scenario, Dr. Vadivelu recommends creating a solid multimodal plan with built-in flexibility. But the first key step, she explains, is to take the patient's baseline chronic-opioid requirements into account and meet them.
Calculate the patient's 24-hour oral opioid dose being taken prior to surgery, then convert that to an IV dose. (Managing moderate to severe postop pain ideally includes a patient-controlled analgesia [PCA] pump in the first 24 hours because most patients can't take orals the first day.) To be safe, Dr. Vadivelu says, this opioid amount taken before surgery is given in the basal rate while additional doses are available in the form of rescue doses, usually every six to 10 minutes as needed. Patients can then titrate the amount they require via PCA.
A typical IV PCA rescue dose, Dr. Vadivelu explains, would be 0.2 mg hydromorphone or 1 mg of morphone every six minutes as needed. And the patient needs to be assessed for pain control, with the amount of rescue doses titrated accordingly. "This will usually allow for at least 25% over the patient's total daily dose being available in the form of rescue doses," she says.
"It's a balancing act," Dr. Vadivelu admits. "Close monitoring is essential, especially at night when patients might not be as well monitored."
Paul Grant, MD, is a hospitalist with the University of Michigan at Ann Arbor who directs the perioperative and consultative medicine service. He agrees that uncontrolled pain and opioid withdrawal can be avoided—as long as hospitalists have the right information on what therapies patients use on a chronic basis. He likewise uses that information as a starting point, even if that's 30 mg of morphine twice daily.
"You continue that home regimen, with the understanding that the amount won't affect their acute postop pain," Dr. Grant says. "Then you go above and beyond."
Unfortunately, there is no exact dosing schedule that hospitalists can follow because the baseline needs and health of opioid-tolerant patients are all different. But Dr. Grant urges hospitalists to be aggressive with short-acting PO, IV or PCA medications within the first 24 hours.
"A lot of physicians are uncomfortable doing this when patients are already on such high doses," he says. "The idea is to not touch their long-acting home opioids—whether it's extended-release morphine, long-acting oxycontin or a fentanyl patch—and titrate the short-acting ones frequently. Don't be afraid to titrate if the patient is in objective pain."
When it comes to that frequent titration, Dr. Grant adds, hospitalists tend to be too conservative, to patients' detriment. If the patient is alert and maintaining a normal heart rate and blood pressure, he explains, doctors can titrate doses safely.
But Dr. Grant adds this caveat: For patients known to be on very high opioid doses before admission—the hip-replacement patient on twice-daily 100 mg of long-acting morphine, for example—try to get the maintenance dose down during the weeks leading up to the admission.
"I explain to patients that we're more likely to successfully manage their pain postop if they get down to, say, 60 mg twice daily," he says. "They usually understand."
Transitioning to orals
After 24 hours, the strategy is to start converting to oral medications as quickly as possible. Dr. Grant will commonly treat patients with IV opioids (preferably via PCA) on postop days Nos. 0 and 1, then convert them to orals if they're eating. Even with orals, hospitalists should order considerably higher doses than they would for opioid-naive patients. While Dr. Grant would prescribe 15 mg morphine tablets for opioid-naive patients, for instance, he might go with 30 mg or higher for those who are opioid-tolerant.
Keri Mason, DO, a hospitalist in Cape Coral, Fla., has extensive experience with chronic-pain patients as a result of her previous military practice. She also opts for aggressive early dosing.
"With narcotic-tolerant patients, I start with 1 mg IV dilaudid every three hours, but only 0.5 mg in my opioid-naive patients," she says. (These doses are in addition to maintaining the home regimen.) "Here's my threshold: If patients get to 2 mg every three hours and I can't control them, I get pain management involved."
Dr. Mason also notes that with opioid-tolerant patients admitted with an uncomfortable but not particularly painful condition such as COPD exacerbation, she typically does not add additional opioids.
Medication reconciliation MIA?
Hospitalists managing opioid-tolerant patients who have been evaluated preoperatively or pre-admission in a hospitalist-run clinic have the benefit of "inheriting" a pain-management plan developed by a colleague. Otherwise, hospitalists may not be in the loop about patients' chronic opioid use, either because the information isn't available— as with patients coming in through the emergency department—or the medication reconciliation isn't complete.
Jason Ham, MD, who directs the adult medical observation unit at the University of Michigan, runs into that situation often. Opioid-tolerant patients with a chronic-pain issue might come in for an acute exacerbation or a new problem like abdominal pain.
"Some patients will be easily recognized on admission as having a chronic-pain syndrome, but others might not be," says Dr. Ham. "So while you're investigating the cause of the acute pain, working up a possible acute appendicitis or dissecting abdominal aortic aneurysm and you discover they're on chronic opioids, you've got to treat their chronic pain." In such complicated situations, Dr. Ham says, you can safely maintain patients on an IV drip until they can go back on orals.
"I also like to check on patients during the night to see that they are sleeping comfortably on the prescribed regimen," he notes. "Then it is easy to calculate the oral dosing in the morning after they wake up."
In other cases, hospitalists might be managing surgical patients who may have been cleared for surgery by a primary care physician but not identified as being opioid-dependent or -tolerant. "PCPs are wonderful," says Dr. Ham, "but many times when they do a preop evaluation, they may not address specific perioperative issues a hospitalist faces, like opioid tolerance."
Problems with under-treatment
When doctors aren't sure what patients are taking, Dr. Ham advises turning to state-controlled drug registries, which are also known in some states as prescription monitoring programs. These registries can be a valuable resource when there's no other reliable source of data. "The prudent hospitalist should use the registry to understand the patient's baseline use of narcotics," he says.
And contrary to another common misconception, strategies for managing acute pain in opioid-tolerant patients should be the same for patients who are either addicted or recovering from opioid addiction. Addiction medicine specialist Daniel Alford, MD, MPH, medical director of the office-based opioid treatment program at Boston Medical Center, advises hospitalists to be very careful not to undertreat pain in those two patient groups.
"Keep in mind that the consequence of under-medicating patients because of their history of addiction will be to increase their level of anxiety. The pain-relief seeking behavior that results is often mislabeled as 'drug seeking,' and it might ultimately compromise patients' ability or willingness to get their full postop treatment," says Dr. Alford, underscoring the danger of patients leaving against medical advice. "For the recovering patient, exposure to an opioid may be a trigger, but less so in the acute pain setting. Moreover, I don't know what's a bigger trigger: unrelieved acute pain or exposure to the molecule they were previously addicted to."
In such cases, hospitalists should have an open conversation with patients, explaining that opioids will be needed despite their history of addiction. Physicians should also explain that most recovering patients in acute pain don't get the euphoria from opioids that they would in a pain-free state.
Just about any patient with acute pain can benefit from adjuvant therapies. But use of such therapies is a must with opioid-tolerant patients on high doses, says Linda Milhoan, ARNP, a nurse practitioner who has extensive experience with pain management and who works with the hospitalist group at Providence Regional Medical Center in Everett, Wash.
"If you use good adjuvant therapies along with their opiates," Ms. Milhoan says, "a lot of the adjuncts will actually have an opioid-sparing effect. When you look at patients' 24-hour total, they'll use way less opiates than if you just do monotherapy with opiates."
Her personal goal, she explains, is to keep opioid-tolerant patients at about 30% above their chronic daily opiate use. "That's completely reasonable, in most cases," she says. But she notes that providers not knowledgeable about the value of adjunctive therapies in chronic pain may quickly get these patients to 100% of their daily usual requirements either via IV, PCA or oral. "Our team is often consulted for assistance when this happens."
Ms. Milhoan describes her management of a typical opioid-tolerant patient: a man in his late 40s with chronic back pain who is in for abdominal surgery. In addition to continuing the patient's home regimen and adding short-acting opioids, she may prescribe 1000 mg of acetaminophen (Tylenol) three times a day, up to 1000 mg of methocarbamol (Robaxin) three times a day, and/or hydroxyzine (Vistaril) on a scheduled basis: 50 mg every six hours.
"And if the patients are already on Neurontin or Lyrica for nerve pain, I start that right after surgery," Ms. Milhoan says. "If not, we add Neurontin—300 mg three times a day—while they're in the hospital because for most patients with chronic pain, there's likely a neuropathic component."
And if the topic isn't complicated enough, there's one more area associated with high opioid doses that's fraught with problems: the potential for developing opioid-induced hyperalgesia, also known as hyperalgesia syndrome. In this paradoxical phenomenon, patients taking chronically high doses may experience reduced analgesic effect and increased pain sensitivity, even when doses are increased.
"This happens more commonly than hospitalists might expect," Dr. Grant explains, who notes that about 5% of opioid-tolerant patients develop the syndrome. "This can be difficult to tease out, but when you do, the strategy is to start lowering the doses right away."
Bonnie Darves is a freelance health care writer based in Seattle.
Big benefits from PCAs
Some hospitals may restrict granting anesthesia-level or pain-physician privileges for a patient-controlled analgesia (PCA) pump. But PCAs can be managed safely and well by hospitalists who have received the requisite training.
That's according to Jason Ham, MD, who directs the adult medical observation unit at the University of Michigan at Ann Arbor. “In most instances with these patients, PCAs actually would be safer than IV push opiates," he points out. "You are delivering a constant dose of the medication with a lower bolus that is locked out. And we know that patients on PCAs over a 24-hour period often use less opiates than they would with IV push orders.”
But unfortunately, he adds, "PCAs are underused by hospitalists.” PCA management requires understanding the total dose patients would receive and the pharmacokinetics of pain medication. Hospitalists should have a good handle on both those skills sets from using IV push orders.
"It really comes down to understanding the mathematical formula of using a PCA," says Dr. Ham. "Hospitalists should know how to use a PCA just like any other procedure."
“If you know how to manage insulin, you can learn how to do this," explains hospitalist David Frenz, MD, a mental health and addiction specialist at HealthEast Care System in St. Paul, Minn. "It’s a matter of understanding the drugs and doses, and getting familiar with the equianalgesic table."
Dr. Frenz cites UpToDate’s tables as well as other pain-control modules as good go-to resources. “The point is to develop a plan,” he says, “but to also be prepared to make adjustments and use boluses with opioid-tolerant patients.”
In some patients on chronic opioids, Dr. Frenz adds, doses needed to control pain may be two to four times those required by patients who are opioid-naive.
"If the patient is NPO," he says, "take their oral dose and run it through the equianalgesic table to calculate the equivalent parenteral dose." From there, "you fudge up by two to four times, compared to opioid-naive patients."