News

Pain at the Pump


 

Patient-controlled analgesia (PCA), well accepted and widely used to quickly ease post-operative and acute pain, is safe and effective—in skilled hands. But there are complications, caveats, and safety concerns hospitalists should consider to incorporate this tool into their pain management routines and hospital protocols.

Studies show patients prefer the PCA compared with other analgesic routes.1-2 Less clear is whether it is more effective or leads to lower opioid use.

Some hospitalists use the PCA for their patients with pain—others defer to anesthesiologists, pain services, or palliative care consultants to manage the PCA and its multifaceted dosing requirements.

“There are a lot of misconceptions about the PCA,” says Deb Gordon, RN, MS, FAAN, senior clinical nurse specialist and pain consultant at the University of Wisconsin (UW) Medical Center in Madison. “There is a misunderstanding that the PCA is a magic black box for pain relief,” which can lead to its overuse. As a general rule of pain management, patients prefer the oral route of analgesic administration, Gordon says, unless that is a problem or rapid titration is needed.

“I don’t think [the PCA is] rocket science—it’s just a tool to deliver analgesics conveniently,” Gordon says. “I think every hospitalist should learn how to use the PCA, but there are always nuances of how to titrate opioids by any route.” UW has implemented PCA protocols, which staff can use for ballpark dosing recommendations.

Target PCA for Safety Programming

Many hospitals have policies, protocols, or guidelines for how to use the PCA. These may address recommended drugs and specific doses, as well as titration, monitoring, and other concerns—even who is credentialed to operate the PCA. If your hospital does not have such resources, this is a good project for a multidisciplinary, ad-hoc quality group—convened and led by hospitalists—to review the literature and develop policies and orders specific to your institution.

Chandler Regional Hospital in Ariz., implemented a revised PCA policy in May 2006, after reviewing the latest pump technology and selecting a new PCA system for the hospital. The eight-page hospital policy spells out how the PCA will be used, while a detailed physician order sheet summarizes the policy and guides choice of drug, dose, lockout interval, and how to increase dosage.

“Since employing the new policy and technology, we definitely feel we provide a safer environment for PCA administration within the hospital,” says clinical pharmacist Anthony Lucchi, PharmD.

The University of Utah Medical Center in Salt Lake City has taken PCA safety a step further by certifying its physicians in PCA use with a brief seminar and a test on the content. The self-learning “Module on PCA and Acute Pain Management” is offered online and takes about an hour to complete, says Dirim Acord, APRN, pain clinical nurse specialist and education coordinator for the medical center’s acute pain service. The pain service handles complex pain procedures but encourages residents and their attendings to become certified in PCA use. Roughly 30% of attendings in the facility, including some hospitalists, have done so.

“The knowledge difference between physicians who have gone through the course and those who have not is quite dramatic,” she adds. “Residents are just not getting this information in their basic training.”

For more information on Chandler Hospital’s PCA policy and order sheet, contact Donna Nolde, dnolde@chw.edu. For information on the University of Utah’s PCA policy and self-learning module, contact Dirim Acord, Dirim.Acord@hsc.utah.edu.—LB

How Hospitalists Use the PCA

The PCA delivers pain medication intravenously via a computerized pump with a button the patient can press when needed—without waiting for busy nurses to answer a call button and then confirm, prepare, and administer an analgesic treatment.

Hospitalists at UW, including Rob Hoffman, MD, often order the PCA. “It’s very well-liked by patients, who are not dependent on a busy nurse to get their analgesics administered,” Dr. Hoffman says. “The biggest concern, involving overdosing patients who are opioid-naïve, may be somewhat overblown. I haven’t experienced problems with my patients being over narcotized, but I start with a low dose and monitor them frequently.”

PCA technology can tabulate how much analgesic the patient has received during the previous 24 hours, Dr. Hoffman notes. “You know that’s a safe dose for the patient, and you can use it to make the transition to oral medications,” he says.

“Most of the patients I have on PCAs are palliative care patients,” says Rachelle Bernacki, MD, MS, a hospitalist, palliative care physician, and geriatrician at the University of California-San Francisco Medical Center. “I use it somewhat differently for the patients in my hospitalist practice—for example, for those who are experiencing intermittent, unpredictable episodes of abdominal pain. It’s also useful for patients with a need to feel in control of their situation. For constant, predictable pain, it’s better to use an around-the-clock schedule. I also send certain patients home on PCAs, especially if they are going to hospice care.”

Dr. Bernacki notes that some of her patients kiss the PCA button as if it were a long-lost friend, including one she recalls who had a bowel obstruction and had not found relief prior to starting on the PCA. But she also recalls a patient for whom the PCA was not a solution. “He was Cantonese-speaking,” she says. “Despite the presence of an interpreter and several attempts at education, he was never able to understand the connection between the PCA button and relief for his pain. We just couldn’t cross the cultural and language barriers.”

Hospitalists probably underuse the PCA, says Mahmood Shahlapour, MD, hospitalist and palliative care consultant at Chandler Regional Hospital in Chandler, Ariz. “Some hospitalists may feel uncomfortable with it,” he says. “I think it’s important for hospitalists to try to get more experience and comfort to be able to use it for the right patient and the right setting.”

What Is the PCA?

PCA technology as we know it today was pioneered in the early 1970s. Now it’s routine for post-surgical pain management. It is used for patients who have trouble taking oral medications or who need rapid response to acute pain crises. Increasingly, it is also used for patients with moderate to severe chronic pain related to cancer or who are being followed by hospice or palliative care services.

PCA refers both to the process of patient self-administration of parenteral analgesics and to the computerized infusion pump that makes this control possible. Recent advances in pain management also include patient-controlled epidural and transdermal analgesia systems—and other new pain modalities continue to be developed.3 Patients unable to operate the equipment themselves—for example, neonates or infants—may receive nurse-controlled analgesia, but experts say this should only be done within carefully defined parameters.

Considerations for PCA Use

Patient selection: The first requirement of the PCA is a patient able to exercise choice and control. Patients who have physical, psychological, or cognitive impairments or are fearful, demented, confused, unresponsive, paralyzed, or very young (under age 7) are not good candidates. Pain in cognitively impaired patients generally is controlled more effectively with scheduled doses or continuous infusions. Post-operative patients are the most common PCA candidates in the hospital, along with those who have sickle cell, cancer, pancreatitis, or other moderate-to-severe acute pain syndromes. Hospitals may consider developing patient selection criteria as part of their PCA policies.

Drug choice: The most common drug used in PCAs is morphine, considered the gold standard in opioid analgesic treatment. Hydromorphone (Dilaudid) is a second choice, especially for patients who are morphine-intolerant or have kidney failure. Fentanyl is another option, but because it is short acting and more potent, fentanyl (or other nonstandard PCA orders) is often reserved for pain or palliative care services. Meperidine is also used in PCAs, but generally is not recommended as an analgesic by pain experts.

Dosing: Standard equianalgesic conversion ratios between opioids and oral and intravenous routes of administration are foundational tools for hospitalists working with PCAs.7 Typical demand doses of morphine in PCAs for opioid-naïve patients are 0.5, 1.0, or 2.0 mg., although a 1989 study suggested that the lower number may be too little and the higher number too high for effective pain management.8 Another consideration when the initial dosage proves insufficient to manage the patient’s pain is to titrate up the demand dose rather than the basal rate. This approach allows a quick response to immediate pain without “stacking” opioids in the bloodstream. Then, based on the patient’s experience over the previous 24 hours, it will be clearer if the basal rate needs titrating upward—and what is a safe basal rate. “Ideally, what you want is to see the patient taking three to five demand doses per day,” Dr. Bernacki says. “If there are 20 or more, you may have undershot the dosing need—but if there are none, you may have overshot it.”

Safety monitoring: Given that opioids are used with PCAs, it is important to monitor the patient for respiratory depression or inadequate analgesia. Special caution is urged for the opioid-naïve, the very young or old, and patients with high opioid requirements or who have pulmonary conditions, asthma, obesity, or sleep apnea. Orders for PCAs can include monitoring expectations for nurses and instructions to decrease the dose if oversedation is detected. Pain experts emphasize the importance of monitoring respiration quality or depth—not just frequency—and of observing the level of consciousness before rousing the patient; being able to rouse an over-sedated patient may be misleading. Pulse oximetry is a standard monitoring technique, but hospitalists may also consider using capnography (carbon dioxide monitoring), especially for patients considered at higher risk.

Other safety concerns: Two July 2003 alerts by the Institute for Safe Medication Practices included recommendations such as testing PCA equipment before purchasing it. Prescribers must undergo a privileging process, providing ongoing information about PCA safety hazards to clinicians, establishing patient selection criteria for the facility, and developing PCA standard orders. Safety concerns include human error and machine error.9 Approaches such as bar coding recognition devices for medication and double-checking PCA inputs by nurses are recommended. Having oxygen and naloxone (Narcan) readily available is another precaution for using opioids. Standard recommendations for any opioid prescribing include watching out for drug interactions and ordering a stool softener to prevent constipation. —LB

With the more typical intravenous PCA, the computerized pump allows for a number of variables, including:

  • An initial bolus or loading dose to bring the pain under immediate control—an important but sometimes overlooked consideration in the successful use of PCAs;
  • The patient-initiated or demand dose, available to the patient at the press of a button;
  • The delay interval or lockout, typically between six and 15 minutes, allowing the analgesic to achieve its peak effect before another dose can be administered. The number of unsuccessful demands by patients during lockout periods is important for the physician to know;
  • A continuous infusion or basal rate to provide continuous pain relief, although this may be contraindicated for opioid-naïve patients starting on PCAs.4 For those receiving opioids for chronic pain, the basal rate could be their current analgesic dose converted to the intravenous equivalent. Alternatively, the patient could receive this dose in a long-acting oral analgesic, with the PCA used for incidental or breakthrough pain. A basal rate also helps patients sleep, their pain controlled without having to wake up to press for a dose;
  • A maximum volume of drug to be administered within a defined period of one, four, eight, or 24 hours, calculated to prevent an opioid overdose—regardless of how many times the PCA button gets pushed; and
  • Monitoring devices such as pulse oximeter or end-tidal carbon dioxide monitor may be part of the PCA system to help warn of emerging respiratory depression.

The fundamental challenge for physicians lies in balancing the loading, basal, and patient-initiated doses with an appropriate maximum to make sure the patient gets adequate pain relief but doesn’t overdose. This is a more complex, multifaceted mathematical formula than ordering opioids to be administered two, three, or four times a day.

A basic safeguard of the PCA for preventing overdose is that when the opioid analgesic starts to make the patient drowsy, he or she is likely to stop pressing the button for another dose. However, for this to work, the PCA must be patient-controlled. If a nurse or family member pushes the button on the patient’s behalf out of a well-meaning desire to keep pain in check, this raises the risk of overdose.

In the past few years, several national quality and safety organizations have issued alerts about the danger of such patient-controlled analgesia by proxy. The Institute for Safe Medication Practices (ISMP) in Huntington Valley, Pa., issued two safety alerts in July 2003 discussing how potentially life-threatening errors can occur with PCAs and offering ways to prevent such errors.

U.S. Pharmacopeia’s summer 2004 USP Quality Review also offered safety recommendations based on analysis of medical errors directly resulting from PCA by proxy. The Joint Commission issued a Sentinel Alert on Dec. 20, 2004, noting that “serious adverse effects can occur when family members, caregivers or clinicians who are not authorized become involved in administering the analgesic for the patient by proxy.”5 Earlier this year the American Society for Pain Management Nursing issued clinical practice recommendations for how nurses can deal with the problem of PCA by proxy.6

Well-designed hospital PCA protocols will address this problem by including clear instructions to family members not to push the button for the patient, with an explanation of why this can be dangerous. Printed brochures and signs in the patient’s room are also helpful.

The Need for Training

“Physicians, as a rule, don’t receive adequate training in the PCA,” says Jean Youngwerth, MD, hospitalist, palliative care consultant and fellowship associate director at the University of Colorado Health Sciences Center in Denver. “Then you’re expected to know how to use it. There clearly is a need for this kind of training in the basics of the PCA, but a brief in-service should be sufficient.”

Dan Johnson, MD, regional department chief for palliative care for Kaiser-Permanente in Colorado, says the level of experience with the PCA is highly variable among physicians he works with. “Some know how to use the PCA and actually do it quite well. Many others are not adequately trained,” he says. “When I test residents with a few questions, they customarily do very poorly. Some of the answers I see make me nervous.”

Dr. Johnson offers a refresher on the PCA for hospitalists in the Denver area who attend an annual palliative care retreat. Those who come regularly seem to retain the information he offers. “If I were in a hospital that had not rolled out PCA standing orders, I’d make sure that there were educational units provided for hospitalists,” he says. “I’d also investigate how to develop standing orders for the hospital.” TH

Larry Beresford is a frequent contributor to The Hospitalist.

References

  1. Hudcova J, McNicol E, Quah C, et al. Patient controlled opioid analgesia versus conventional opioid analgesia for postoperative pain. Cochrane Database Syst Rev. 2006;4.
  2. Ballantyne JC, Carr DB, Chalmers TC. Postoperative patient-controlled analgesia: Meta-analyses of initial randomized controlled trials. J Clin Anesth. 1993 May/June;5(3):182-193.
  3. D’Arcy Y. New pain management options: Delivery systems and techniques. Nursing. 2007 February; 37(2):26-27.
  4. Pasero C, McCaffery M. Safe use of a continuous infusion with IV PCA. J PeriAnesthesia Nursing. 2004 Feb;19(1):42-45.
  5. Joint Commission. Patient-controlled analgesia by proxy. Available at www.jointcommission.org/SentinelEvents/SentinelEventAlert/sea_33.htm. Last accessed July 12, 2007.
  6. Wuhrman E, Cooney MF, Dunwoody CJ, et al. Authorized and unauthorized (“PCA by Proxy”) dosing of analgesic infusion pumps: Position statement with clinical practice recommendations. Pain Manag Nurs. 2007 Mar;8(1):4-11.
  7. Prommer E. Fast Fact and Concept #92, Patient controlled analgesia in palliative care. End-of-Life/ Palliative Education Resource Center, Medical College of Wisconsin, Milwaukee:www.eperc.mcw.edu/ff_index.htm.
  8. Owen H, Plummer JL, Armstrong I, et al. Variables of patient-controlled analgesia. 1. Bolus size. Anaesthesia.1989 Jan.;44(1):7-10.
  9. Vicente KJ, Kada-Bekhaled K, Hillel G, et al. Programming errors contribute to death from patient-controlled analgesia. Can J Anesth. 2003;50:328-332.

How to Titrate the PCA

Teaching guidelines developed by Jean Youngwerth, MD, hospitalist and associate director of the palliative care fellowship program at the University of Colorado Health Sciences Center in Denver. Dr. Youngwerth says she has not found good published guidelines for PCA titration and uses the following guidelines when she teaches residents about pain management and PCAs.

  • Opioid naïve: No basal rate to start; and
  • Chronic opioid use: Use basal rate at equianalgesic dose of chronic opioid.

Parameters:

  • Calculate basal rate (equianalgesic dose of current opioid);
  • Incremental dose: 50%-100% of basal rate;
  • Lockout time: eight to 10 minutes (six-minute lockout for fentanyl);
  • Loading dose: Twice the incremental dose (or 10% of 24-hour dose);
  • Can change incremental dose at least every 30-60 minutes (use for acute pain control; rapid titration). For mild to moderate pain, increase dose by 25%-50%; for moderate to severe pain, increase dose by 50%-100%; and
  • Can change basal rate every eight hours or greater (do not increase by more than 100% at a time).

Dr. Youngwerth emphasizes that these guidelines have not been formally approved by the hospital or implemented as standard practice. They are offered as general information to aid others in developing hospital PCA policies. These rough guidelines should not be construed as medical advice, and clinicians should always take into account patient-specific factors.

Guidelines for PCA use specifically for palliative care patients can be found at the End-of-Life/Palliative Education Resource Center of the Medical College of Wisconsin, in “Fast Fact and Concept #92, Patient controlled analgesia in palliative care”: www.eperc.mcw. edu/fastFact/ff_92.htm.—LB

Next Article:

   Comments ()