Patient-controlled analgesia (PCA) by proxy—activation of the PCA pump by anyone other than the patient, whether authorized or not—is a controversial practice.1 Many supporters of authorized agent-activated PCA argue that if the patient can't operate the PCA, having a nurse or other authorized agent push the PCA button can provide adequate analgesia (see Defining PCA by proxy and AACA). This type of PCA by proxy has been used successfully in pediatric settings, but as the practice was transferred to other medical areas, it's been used for less than ideal candidates, such as cognitively or physically impaired adults.1
Because most adults can self-administer PCA doses, the use of an authorized agent to push the PCA button for the patient is most commonly found in the pediatric setting, with a family operating the PCA for a child who's unable to do so. The best literature support for this authorized agent-controlled analgesia (AACA) is in pediatrics; information related to adult use of it is scant. The unauthorized activation of PCA isn't endorsed by The Joint Commission (TJC), Institute for Safe Medication Practices (ISMP), or other organizations. However, the use of AACA has the support of the American Society for Pain Management Nursing (ASPMN), as long as the facility has clear guidelines for when AACA can be used and for monitoring to ensure patient safety (more on this later).
If the patient isn't the person activating the PCA button, should we call the pain management technique PCA? This question has prompted discussion at many levels. Among the questions raised are: What are the safety issues related to PCA by proxy? Should another type of pain management be used for patients who can't activate the PCA button? This article focuses on safe PCA use and AACA.
The PCA concept
PCA was developed in the 1970s to provide easier, quicker, and more effective pain relief for surgical patients.2 Before then, I.M. injection and oral medications were the standard of care for postoperative pain management. Patients liked the idea of PCA because it provided a pain relief option that was ready when they needed it and they had more control over their medication delivery and pain management.
In general, PCA includes the use of a device that's preprogrammed to deliver a prescribed medication. The device contains a bag or syringe of medication that flows through I.V. tubing to the patient's venous access when the patient pushes the PCA button, providing pain relief.
For PCA to be effective, the patient should first be given prescribed I.V. bolus doses of analgesic until comfort is achieved; the patient-activated doses can then be used to maintain comfort. Opioid polymorphisms (differences in the way patients react to medications based on genetic predisposition) may affect the way that any one drug provides pain relief for the patient.2,3
Most PCA prescriptions have the following elements:
- A loading dose—usually twice the amount ordered in the bolus dose
- A bolus dose
- A basal dose option for opioid-tolerant patients
- A time period between doses
- A 1-hour or 4-hour lockout time period—that is, a maximum number of doses allowed in 1 or 4 hours.
Some order sets contain a prescription for additional medication if vascular access is lost, or prescribe a clinician bolus that can be given if the patient has increased pain (such as with activity). Prescriptions for antiemetics, opioid reversal agents, laxatives, and patient monitoring parameters may also be included.
The most common medications used for PCA are morphine, hydromorphone, and fentanyl. The medication choice is based on prescriber patterns and patient response. Should one medication fail to provide adequate analgesia after dose adjustments or if the patient develops intolerable adverse reactions such as nausea, switching opioids may provide better analgesia and decrease adverse reactions.
Preprinted and standardized order sets are recommended along with standardized medication concentrations.4,5 In the past, continuous infusions were ordered for patients in the hopes of providing analgesia while the patient slept. Current practice recommendations are to avoid the use of continuous infusions for opioid-naive patients, as the continuous infusion in these patients doesn't improve analgesia and can increase the risk of oversedation and subsequent respiratory depression.3,6
PCA has a built-in safety mechanism: the patient stops pushing the button when he or she starts to become sedated. Interrupting this negative feedback loop by using someone else to activate the PCA button can put the patient at risk for oversedation and respiratory depression.7 Along with continuous infusions and PCA by proxy, taking the patient out of PCA seriously compromises patient safety.
Guidelines for PCA use
Most of the literature on PCA by proxy centers on the safety dangers of the practice and the use of AACA in pediatric settings. In a review of patient safety data from the U.S. Pharmacopeia Medication Error Analysis database, 6,069 PCA errors of all types were listed; 460 of these resulted in patient harm or death. Twelve of the 460 errors were attributed to PCA by proxy, with one patient death the result of nurse-activated PCA.6,8 Error tracking by TJC isn't complete, as it relies on voluntary reporting by hospitals and healthcare practitioners, and estimates of errors may be lower than the actual number of errors.
Most healthcare providers agree that PCA is a valuable contribution to pain management. However, careful patient selection and monitoring are needed to ensure that each patient is safe during PCA.
PCA has been used effectively in the pediatric setting for many years to control cancer pain and postoperative pain, and is a useful option when oral medications can't be used. Children as young as 5 have successfully used PCA to control pain.3
A survey of American pediatric anesthesiologists in 252 institutions was undertaken to determine how I.V. PCA was provided to children; the results also shed light on how PCA by proxy was being used. I.V. PCA was available to pediatric patients at 96% of the institutions surveyed; PCA by proxy was available at only 38%.9 Eleven percent of the respondents indicated that PCA by proxy was discontinued after the TJC 2004 sentinel event alert (see TJC recommendations for PCA by proxy), 42 survey respondents recalled patients having received naloxone to counteract cardiopulmonary adverse effects of opioids during the year before they completed the survey, and eight respondents recalled deaths during the last 5 years in patients receiving I.V. PCA, I.V. PCA by proxy, and continuous non-I.V. PCA opioid infusions.9 Only 40% of 234 institutions provided educational material for patients and family on I.V. PCA. Providing educational materials was cited as an intervention that could have a positive effect of PCA use.
Reviewing pediatric literature on PCA use, Franson found a large number of adverse events in 145 children using PCA by proxy and in 157 self-administered PCA patients.10,11 The PCA by proxy group required interventions such as airway management, naloxone, or admission to the ICU; the self-administered PCA group needed supplemental oxygen or decreased opioid doses. Recommendations for change included the use of continuous pulse oximetry and sedation monitoring during PCA and PCA by proxy use to assist in early recognition of respiratory depression and adverse outcomes.
A study of pediatric oncology patients who were opioid-tolerant looked at 4,972 24-hour periods of PCA use by 1,011 patients and compared patients who self-administered I.V. PCA and those who had PCA by proxy. Only four patients (less than 1%) in the PCA by proxy group had complications, compared to about 1.5% of patients in the self-administered group.12 The explanation for the low occurrence of adverse reactions in both groups of these patients may be the fact that the patients weren't opioid-naive and that families were more involved with assessing and managing the patient's condition.
The last study included in the Franson review was a study of parent–nurse–controlled analgesia in patients under age 6. This observational study found that 9 of the 212 patients needed naloxone for respiratory compromise.13
Findings from the Franson review indicate that overall, patients and families were satisfied with PCA use, including PCA by proxy. The fact that adverse reactions occurred can be considered to be a result of patient weight, age-related pharmacokinetics, and clinical condition.10 However, most of the studies indicated the need for regular assessment, monitoring, patient and family education, and the use of continuous pulse oximetry for PCA use in the pediatric population.
ASPMN has developed a position paper for the use of PCA by proxy, and has clarified the terms PCA by proxy and AACA.1 According to ASPMN, although AACA carries risks (identified in pediatric literature), it has some advantages for patients because it uses medication that is readily available and can help manage pain in patients who are unable to activate the PCA button. The ASPMN statement clearly identifies key safety points and recommendations for healthcare agencies, prescribers, nurses, and caregivers.1
Using AACA safely
PCA by proxy by an unauthorized agent isn't recommended by the ISMP, TJC, or ASPMN.1,4,14 Well-meaning relatives or hospital staff could oversedate the patient in the name of providing pain relief, leading to serious patient complications and even death.
To use AACA safely, facilities should establish guidelines for who can activate the PCA button and how AACA is to be done. Monitoring parameters also need to be defined to ensure patient safety. Facilities should have a method of identifying the patients on AACA to all healthcare providers involved in the patient's care, and parameters for measuring the effectiveness of PCA therapy.1
Facilities also need to have a way to identify patients who aren't good candidates for PCA, and a way to define which patients are candidates for AACA. For example, obese patients, confused patients, and patients with sleep apnea or asthma may not be good candidates for PCA, so an alternate method should be considered and the pain management methods individualized.2,6 For AACA, the organization will need to provide guidelines not only for patients who are candidates but also for who can serve an authorized agent.1
Monitoring PCA and AACA
In the pediatric literature review, one of the recommendations for using PCA was to provide monitoring parameters for all patients on PCA and to use continuous pulse oximetry. Pulse oximetry is recommended for all patients using PCA, and emerging recommendations indicate that combining continuous pulse oximetry and capnography (which measures end-tidal carbon dioxide levels) can provide a more comprehensive indication of increasing sedation.6
Assess patients on all types of PCA with a standard pain intensity rating tool to determine if their pain is being managed effectively.6 Follow your facility's policy for the frequency of assessing pain intensity in patients using PCA. Assessments every 4 hours are common once the patient has stabilized, or assessment can be performed more frequently in response to changes in the patient's condition or pain management needs.
Monitoring for sedation should be done consistently and include not only a respiratory rate but also respiratory depth and quality, patient alertness, vital signs, and the use of a sedation scale. A simple scale (ranging from 1, alert and awake, to 4, somnolent with minimal response to stimulation) can be used to alert nurses to increasing patient sedation levels. All nurses should be trained in recognizing the stages of sedation and be comfortable with implementing the actions needed to avoid oversedation and respiratory arrest.
Patient and family education
If PCA will be part of the pain management regimen, teach patients and families how to use it, with printed materials, videos, or individual patient education provided by nurses. The prescription should be for PCA or AACA but not both.1 Once the patient is able to use PCA, it should replace AACA.
Explain to families that under PCA, the patient is the only person who should push the button. If this rule is violated despite repeated enforcement, the prescriber should consider other means of pain management, such as intermittent I.V. medications or a continuous infusion with additional bolus doses for opioid-tolerant patients.
If AACA is used, teach authorized agents how and when to activate the PCA button for the patient, and when not to activate the PCA button, such as while the patient is sleeping.1
PCA isn't push-button pain management, but a system that requires constant assessment and adjustment based on the patient's response. No matter which type of PCA is used, attention to the patient and how he or she responds to the medication, along with educating patients and families about how to use PCA, is essential for optimal patient safety.
Defining PCA by proxy and AACA
PCA by proxy is activation of the PCA pump by anyone other than the patient, whether that person is authorized or unauthorized to do so.
AACA is PCA in which a consistently available and competent individual is authorized by a prescriber and properly educated to activate the PCA dosing button when the patient is unable, in response to the patient's pain. This definition includes both nurse-controlled and caregiver-controlled analgesia (in which the authorized agent is a nonprofessional, such as a parent).1
TJC recommendations for PCA by proxy14
To reduce the risk of PCA by proxy, TJC made the following practice recommendations in its 2004 sentinel event alert:
- Develop criteria for determining which patients should receive PCA. Patients who aren't good candidates for PCA include infants and young children; patients who are confused, agitated, or restless; or patients with impaired level of consciousness, psychological stability, or intellectual capacity.
- Carefully monitor patients, using oximetry and capnography as appropriate.
- Teach patients and family members about the proper use of PCA and the danger of PCA by proxy. Provide written instructions telling family members not to administer PCA doses unless they are designated as an authorized agent.
- Warn staff of the dangers of PCA by proxy outside of an AACA protocol.
- Consider placing warning tags on all PCA delivery devices stating that only the patient should press the button.
1. Wuhrman E, Cooney MF, Dunwoody CJ, Esterowicz N, Merkel S, Oakes LL. Authorized and unauthorized (PCA by Proxy) dosing of analgesic infusion pumps: position statement with clinical practice recommendations. Pain Manag Nurs
2. D'Arcy Y. A Compact Clinical Guide to Acute Pain Management
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3. American Pain Society. Principles of Analgesic Use in the Treatment of Acute Pain and Cancer Pain
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4. Institute for Safe Medication Practices. Safety issues with patient controlled analgesia, Part 1. How errors occur. ISMP Medication Safety Alert.
July 10, 2003. http://www.ismp.org/Newsletters/acutecare/articles/20030710.asp
5. Joint Commission Perspectives on Patient Safety. Focus on five: preventing patient controlled analgesia overdose. Let eligible patients keep control. Jt Comm Perspect
6. D'Arcy Y. Keep your patient safe during PCA. Nursing.
7. Hurley R, Cohen S, Wu C. Acute pain in adults. In: Fishman SM, Ballantyne JC, Rathmell JP, eds. Bonica's Management of Pain
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Philadelphia, PA: Lippincott Williams & Wilkins; 2009:705–706.
8. Flynn F, Mohr L, Lawlor-Klean P. Case Study in brief. Right programming of PCA pumps to prevent errors in the infusion process. Jt Comm J Qual Saf
9. Nelson KL, Yaster M, Kost-Byerly S, Monitto CL. A national survey of American pediatric anesthesiologists: patient controlled analgesia and other intravenous opioid therapies in pediatric acute pain management. Anesth Analg.
10. Franson HE. Postoperative patient-controlled analgesia in the pediatric population: a literature review. AANA J
11. Voepel-Lewis T, Marinkovic A, Kostrzewa A, Tait AR, Malviya S. The prevalence and risk factors for adverse events in children receiving patient controlled analgesia by proxy or patient controlled analgesia after surgery. Anesth Anesthesiol.
12. Anghelescu DL, Burgoyne LL, Oakes LL, Wallace DA. The safety of patient-controlled analgesia by proxy in pediatric oncology patients. Anesth Analg
13. Monitto CL, Greenberg RS, Kost-Byerly S, et al. The safety and efficacy of parent controlled analgesia in patients less than 6 years of age. Anesth Analg
14. Joint Commission Sentinel Event Alert. Patient controlled analgesia by proxy. December 20, 2004. http://www.jointcommission.org/SentinelEvents/SentinelEventAlert