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Safety Issues with PCA Part II - How To Prevent Errors

Patient-controlled analgesia (PCA) has considerable potential to improve pain management.However, errors happen frequently, sometimes with tragic consequences. In Part I, published in our July 10, 2003 newsletter, we described how PCA errors happen. Part II presents a checklist of efforts related to practice, systems, products, pumps, and regulations that can reduce the risks associated with this patient-centered technology.

When purchasing a PCA pump

  • Perform a failure mode and effects analysis using the actual PCA pump under evaluation. Examples of questions to explore: Can the pump be programmed easily to deliver the desired concentrations?  Could unsafe administration sets that allow free-flow be used accidentally? Is the pump operation intuitive for the clinician and patient? What are the default settings for the opiate concentrations in use? Do the drugs, units of delivery, and strengths appear in a logical sequence?
  • Limit PCA pumps to a single model to promote proficiency with programming.
  • Before distributing the new pumps, verify that all pump default settings are set up as expected, and place a warning label on the activation button that states "FOR PATIENT USE ONLY."

Before prescribing, dispensing, or initiating PCA

  • Require PCA prescribers to undergo a privileging process to verify proficiency with this form of pain management. Limit the prescribing of fentanyl for epidural PCA to anesthesia staff, pain management teams, or critical care prescribers.
  • Design standard order sets to guide drug selection, doses, and lockout periods; patient monitoring; and precautions such as avoiding concomitant analgesics, and how and when to administer oxygen and naloxone. Test the order sets using the pump's programming sequence to reduce the risk of errors.
  • Provide nurses with relevant information about opiates used for PCA. Alert them to the dangers of administering a dose for the patient (PCA by proxy) and the differences between hydromorphone and morphine.
  • Teach nurses and pharmacists how to program PCA pumps, and verify their ability to enter a PCA prescription accurately. Ensure that training occurs close to the introduction of new pumps, not months before use, and offer practice sessions as needed to maintain proficiency.
  • Run simulations in which staff purposely write incomplete orders; select an inappropriate drug or dose; misprogram a pump; ignore double checks; forget critical monitoring points; and miss obvious signs of toxicity so that clinicians can identify these at-risk behaviors.
  • Ensure that nurses recognize the signs and symptoms of opiate toxicity and withdrawal, the need to assess patients with minimal verbal or tactile stimulation, and the ability to distinguish between oversedation and other pulmonary, neurologic, or cardiovascular complications.
  • Provide ongoing education to clinicians about PCA errors to build awareness, and encourage internal and external (FDA, ISMP, USP) reporting of PCA errors.
  • Require annual competency assessments for all professionals who prescribe, dispense, and administer PCA.
  • Establish patient selection criteria for PCA. Candidates should have an appropriate level of consciousness and cognitive ability to self-manage pain. Infants, young children, and confused patients are unsuitable candidates.

When prescribing PCA

  • Require the use of PCA standard order sets (all sections completed) and limit verbal orders to dose changes.
  • Always dose PCA opiates in mg or mcg, not by volume (mL).
  • Check patient allergies before selecting the opiate used with PCA.
  • Use morphine as the opiate of choice. Use hydromorphone for patients who need very high doses of opiates. Reserve meperidine for patients who are allergic to both morphine and hydromorphone.
  • Consider other medications that the patient has received (e.g., analgesics taken at home, intraoperative medications) or currently has prescribed (e.g., antihistamines, nighttime sedatives) when determining the loading and maintenance doses.
  • Reassess the appropriateness of PCA therapy at regular intervals.

When dispensing PCA

  • Establish one standard concentration for each opiate used for PCA.
  • Stock only the standard concentrations of morphine and hydromorphone in patient care units (meperidine for PCA should be dispensed from the pharmacy).
  • Separate the storage of hydromorphone from morphine in the pharmacy and patient care units to avoid mix-ups.
  • Check patient allergies and ensure that they are listed in the interactive allergy field on the patient profile before entering PCA orders into the computer.
  • Set maximum dose limits for PCA opiates in the pharmacy computer so an alert appears if safe doses are exceeded during order entry.
  • Affix prominent warnings if dispensing an opiate in a nonstandard concentration.
  • Use prefilled syringes/bags/cassettes whenever available commercially. Have pharmacy prepare all PCA products that are not commercially available.
  • Require a pharmacist to review all PCA orders before initiation (exception: when a pharmacist is not on site) and suggest renal dose adjustments or an alternative opiate when appropriate. If meperidine PCA is used, have pharmacy set dose limits and reassess the patient every 24 hours.
  • Use "tall man" lettering on pharmacy-applied labels for HYDROmorphone to help avoid confusion with morphine.
  • Alert clinicians to potential drug shortages with PCA opiates and, if encountered, recommend an alternative drug with clear dosing instructions.

When initiating PCA

  • Check patient allergies, which should be visible on the medication administration record (MAR), before initiating PCA.
  • Connect PCA to a port close to the patient (to avoid dead space) and prominently label the infusion line at this connection to avoid mix-ups with other lines.
  • Provide laminated instructions for programming PCA pumps for reference by nurses who may infrequently initiate PCA.
  • Require two clinicians to independently double-check the patient's identification, drug and concentration, PCA pump settings, and the line attachment before use (and before pump refill or programming change). Bedside bar-coding can be used to verify the patient and drug/concentration; however, pump settings may still require an independent double check.
  • Avoid nurse-controlled PCA unless special monitoring in place (see page 3).
  • Verify PCA settings each shift, immediately after receiving report.
  • Avoid administering concomitant opiates (an alert should appear on the MAR).
  • Have oxygen and naloxone readily available.
  • Educate patients about the proper use of PCA before initiation. Start during the preoperative testing visit so patients are not too groggy to understand. Warn family members and visitors about the danger of PCA by proxy.

When monitoring the effects of PCA

  • Establish a standard measurement scale to assess the patient's level of pain.
  • Develop monitoring requirements for patients who are receiving PCA and be alert for signs of oversedation. At a minimum, evaluate the patient's level of pain, alertness, and vital signs, including rate and quality of respirations, every 4 hours.
  • Evaluate all patients with minimal verbal and tactile stimulation to obtain an accurate assessment of their level of sedation.
  • Monitor patients more frequently during the first 24 hours and at night, when hypoventilation and nocturnal hypoxia may occur.
  • Establish risk factors that could increase respiratory depression (e.g., obesity or low body weight, concomitant medications that potentiate opiates, preexisting conditions such as asthma and sleep apnea) and determine the level of enhanced monitoring that would be required if these patients use PCA (e.g., capnography, apnea alarms at night).
  • Identify the infrequent situations where critical care patients may be suitable for nurse-controlled analgesia, and the level of enhanced monitoring that would be required for these patients.
  • Do not rely on pulse oximetry readings alone to detect opiate toxicity. Since capnography is currently not available for all PCA patients, reserve its use for those with a heightened risk of toxicity, and with nurse-controlled analgesia.
  • Keep flowsheets at the bedside to document PCA doses and patient monitoring.
  • Monitor the use of naloxone to identify adverse events related to PCA.

Recommendations for pharmaceutical companies

  • Improve the visibility of label information about preservatives in opiates.
  • Distinguish the packaging of opiates and the varying strengths used for PCA. Use "tall man" letters for HYDROmorphone to help avoid confusion with morphine.
  • Seek FDA approval of hydromorphone for PCA so the product can be packaged in prefilled syringes or bags for PCA use.
  • Provide wholesalers and healthcare providers with early warnings about potential drug shortages to allow providers time to prepare for short-term alternatives.

Recommendations for PCA pump manufacturers

  • Ensure free-flow protection for all administration sets and extension tubing.
  • Provide visual and auditory feedback to patients about doses that are administered when the activation button is pressed.
  • Require pumps to be programmed in mg/mL or mcg/mL, not just mL.
  • Establish default settings of zero for all opiate concentrations.
  • Change the appearance of the activation button to avoid looking like a call bell.
  • Develop technology to alert users and stop PCA if a syringe or bag is empty.
  • Explore design standards to prevent connecting an IV PCA to an epidural line.
  • Develop technology for PCA to alert clinicians to unsafe dose settings, programming errors, and respiratory depression.
  • Contact healthcare providers immediately when pump problems are recognized.

Recommendations for regulatory bodies

  • Require PCA pump manufacturers to provide a patient guide for use.
  • Enhance FDA communication to providers about PCA problems, and issue hazard alerts or recalls on unsafe devices currently on the market.
  • Require pump manufacturers to perform premarket testing of the device using clinicians and potential patients.
  • Require pump manufacturers to apply existing human factors design guidelines for medical devices.