Current and developing methods of patient-controlled analgesia

Moderate-to-severe acute postoperative pain is commonly controlled with opioids administered via programmable intravenous (IV) patient-controlled analgesia (PCA) infusion pumps. Intravenously administered opioids provide effective relief of postoperative pain, and IV PCA enables patients to control their level of analgesia, which has advantages over nurse-administered approaches, including more satisfied patients and improved pain relief. Unfortunately, commonly used opioid analgesics can cause significant adverse effects. Furthermore, IV PCA has drawbacks, such as device programming errors, system errors, medication errors, limitations in patient mobility, and potential for IV tubing kinks, clogging, and transmission of infection. The IV route of administration is also characterized by a rapid, high peak in analgesic drug concentration followed by rapidly decreasing concentrations. Consequently, respiratory depression, excessive sedation, and inadequate pain control can occur. Furthermore, the technical assembly of an infusion pump is often complex and time-consuming. PCA modalities that incorporate superior opioid analgesics, such as sufentanil, and novel noninvasive routes of administration offer great promise for enhancing the patient and caregiver experience with the use of postoperative PCA.

Efficacy and safety of fentanyl HCl iontophoretic transdermal system compared with morphine intravenous patient-controlled analgesia for postoperative pain management for patient subgroups

BACKGROUND AND OBJECTIVE

Inadequate postoperative pain control remains a problem for many patients undergoing surgery. This study presents subgroup analyses from a large, randomized, multicentre, European study comparing the efficacy and safety of the fentanyl HCl iontophoretic transdermal system and morphine intravenous patient-controlled analgesia for postoperative pain management.

METHODS

The efficacy and safety of the fentanyl iontophoretic transdermal system and morphine intravenous patient-controlled analgesia were evaluated for patients divided by surgery type, sex, American Society of Anesthesiologists physical status and type of anaesthesia used during surgery. Efficacy measures included a patient global assessment of the method of pain control (a rating of 'good' or 'excellent' was considered as a success rating) and mean last pain intensity scores in the first 24 h. Discontinuation rates and the incidence of adverse events were also evaluated.

RESULTS

Numerically similar percentages of patients in most subgroups reported success on the last patient global assessment in the first 24 h for both the fentanyl iontophoretic transdermal system and morphine intravenous patient-controlled analgesia. Similar percentages of investigators reported success ratings on the investigator global assessment at the last assessment for both treatment groups regardless of surgery type, except for the knee surgery subgroup (fentanyl iontophoretic transdermal system, 75%; morphine intravenous patient-controlled analgesia, 95%). Mean last pain intensity scores in the first 24 h after surgery were similar in all subgroups. Rates of patient withdrawals and the incidence of adverse events were generally similar between treatment groups in the patient subgroups.

CONCLUSION

The fentanyl iontophoretic transdermal system and morphine intravenous patient-controlled analgesia are comparably well tolerated and effective methods of pain control, regardless of sex, American Society of Anesthesiologists physical status or the type of anaesthesia used for surgery, and following most surgery types.

Patient-controlled analgesia-related medication errors in the postoperative period: causes and prevention

Patient-controlled analgesia (PCA) is a common and effective means of managing postoperative pain. Unfortunately, the complex processes and equipment associated with the setup, programming and administration of intravenous or epidural PCA have allowed it to become a significant source of preventable medication errors. These errors can be classified into two major categories: human (operator) errors and equipment errors (malfunctions). Such errors are potentially harmful to patients, time-consuming for hospital staff and costly for healthcare providers. The objective of this article is to describe PCA medication errors and examine systems and modalities that may help reduce the incidence of system-related errors. Data from the US FDA's Manufacturer and User Facility Device Experience (MAUDE) database indicate that 6.5% of intravenous PCA-related events were due to operator error. Most (81%) of these errors were due to pump misprogramming, of which almost half were associated with patient harm; 76.4% of adverse events were attributed to device malfunction (e.g. due to frayed wires or a crack in the drug cartridge), although only 0.5% of these were associated with harm to patients. In a report based on data from MEDMARX, a voluntary database that captures reports on medication errors, 7.9% of the PCA-related errors captured over a 5-year period were described as causing harm to patients. Technological advances, such as improved PCA pump designs based on ergonomic and cognitive engineering principles, the use of barcode technology and other 'smart pump' safety features, and new postoperative pain management modalities, may play a significant role in reducing the future incidence and severity of PCA medication errors.

The Rate and Costs Attributable to Intravenous Patient-Controlled Analgesia Errors

Purpose

To estimate the rates and costs of intravenous patient-controlled analgesia (IV PCA) errors from the hospital or integrated health system perspective.

Methods

This study used a cost-accounting methodology to estimate the costs attributable to IV PCA errors in the United States. Data for the study were obtained from the MEDMARX and Manufacturer and User Facility Device Experience (MAUDE) datasets, published literature, and expert opinions. MEDMARX is a voluntary, anonymous, medication-error-reporting database owned and operated by the United States Pharmacopeia. MAUDE is a mandatory, device-error-reporting database maintained by the US Food and Drug Administration. Levels of care rendered as a result of the IV PCA errors were estimated by applying clinical assumptions (validated by an expert advisory panel) to each of the 7 error consequences considered in this analysis. Variable and opportunity costs (2006 values) were considered, including medication, laboratory, lost revenue, and labor. The corresponding costs were applied to the error consequences to derive the estimated mean cost for each error cause. The numbers of errors documented in each dataset and the published literature were used to extrapolate the rate of IV PCA errors annually.

Results

The average cost per error event was $733 in the MEDMARX dataset and $552 in the MAUDE dataset. Harmful IV PCA errors were 120 to 250 times more costly than nonharmful errors. The annual error rates were estimated as 407 IV PCA-related errors and 17 device-related errors per 10,000 people within the United States. Conclusion: Analysis of 2 datasets, MEDMARX and MAUDE, revealed that IV PCA medication- and device-related errors are costly to hospitals and integrated health systems and represent a significant burden on the US health system. This study provided a novel approach to estimating the associated costs of undesired IV PCA-related events. Additional research is needed to validate the methodology (as applied to this area) and results.

Clinical Staff Resource Use With Intravenous Patient-Controlled Analgesia in Acute Postoperative Pain Management: Results From a Multicenter, Prospective, Observational Study

The purpose of this study was to evaluate hospital resource utilization associated with intravenous patient-controlled analgesia (IV-PCA), with a focus on nursing, pharmacy, and central supply/engineering time spent from a hospital perspective. Data were collected during a multicenter (29 sites), prospective observational study in the United States of subjects who underwent total knee replacement (TKR), total hip replacement (THR), or abdominal hysterectomy (AH) and were administered analgesia through IV PCA for the management of acute postoperative pain. Nursing staff recorded the IV PCA-related tasks they performed for a subject and the duration of time required to perform each task from initial IV PCA set-up to discontinuation. Hospital administrators, nursing managers, central supply/engineering staff, and pharmacy directors were interviewed to obtain data regarding other IV PCA labor resource use. The distribution of surgery type among the 457 subjects was 31.1% THR, 35.9% TKR, and 33.0% AH. The average duration of IV PCA use was 32.6 hours. Nurses reported having to perform an average of 39.6 IV PCA-related tasks, which required an average of 67.4 minutes. The most common IV PCA-related tasks were evaluating pump use and settings, assessing the IV site, evaluating and addressing analgesia side effects, instructing/reinstructing the subject on use, administering supplemental pain medications, assisting with self-care or moving the subject, and assisting the subject with use of the button. Pharmacists reported that they spend approximately 7.9 minutes and pharmacy technicians spend approximately 9.8 minutes, per subject daily course of IV PCA therapy, on the following tasks: checking and verifying the order, doing inventory of the analgesia, preparing the analgesia (ie, filling reservoirs), checking the analgesia, and delivering the analgesia to the nursing units. In addition, pharmacists and RNs spend an average of 47.3 and 40.7 minutes per year in IV PCA-related training. Intravenous patient-controlled analgesia postoperative care requires coordination and involvement of numerous hospital departments. It is labor intensive and involves numerous time-consuming tasks, oversight of IV PCA, and ongoing training. Alternative methods of patient-controlled pain management with similar efficacy that reduces labor resource utilization may be warranted.