Patient controlled analgesia (PCA) can be used effectively in emergency department patients dealing with moderate or severe pain, according to results of the Pain Solutions in the Emergency Setting (PASTIES) studies (here and here).

The trials showed significant improvement in pain control in patients with nontraumatic abdominal pain who received PCA over nurse titrated analgesia, and a small but not statistically significant improvement in pain control in trauma patients. Patients who received PCA were much more satisfied with their care.

“Patient controlled analgesia is used to good effect in other areas of the hospital, but not typically in emergency patients,” Jason E. Smith, MBBS, MSc, consultant in emergency medicine at Derriford Hospital in Plymouth, United Kingdom, told Reuters Health by email.

The U.K.-based PASTIES research team conducted two pragmatic, multicenter parallel group randomized controlled trials, enrolling 200 adults with acute nontraumatic abdominal pain in one study and 200 adults with acute traumatic injury in the other study.

The studies included only patients who needed boluses of morphine, titrated and given by a nurse in the ED, and were expected to stay in the hospital for at least 12 hours. “We looked at pain over a 12-hour period—the first study to look at this vulnerable period between emergency care and inpatient care,” Dr. Smith said. Participants in each study were randomly allocated to PCA or nurse-titrated analgesia (usual care).

In the nontraumatic abdominal pain patients, the PCA group reported significantly less pain overall than the usual care group. The PCA group spent 14.5 percent less time in moderate or severe pain over 12 hours, received significantly more morphine (mean difference 12.3 mg), and had about a 2.5-fold increase in the likelihood of being very or completely satisfied with their pain management.

In the acute traumatic injury patients, pain scores were also lower and satisfaction scores higher with PCA, but the differences failed to reach statistical significance relative to usual care.

In an editorial in the BMJ, Fiona Lecky, MB ChB, MSc, PhD, clinical professor of emergency medicine at the University of Sheffield, United Kingdom, said, “The inconsistent results could be due to differing pain mechanisms in the two populations (visceral in abdominal pain, somatic in acute traumatic injury), a type 2 error in the study of acute traumatic injury (whereby the study failed to find an existing difference between treatments owing to methodological factors such as low power), or type 1 error in the abdominal pain study (whereby the study found a difference where none existed).”

“In both studies, the relative increase in satisfaction scores with PCA was greater than the relative reduction in pain scores, suggesting that patients attach more value to autonomy in pain management than to the magnitude of pain experienced,” Dr. Lecky said.

Taken together, the PASTIES studies suggest that starting PCA in the ED is “likely to be beneficial for patients who have needed a bolus of intravenous opiate analgesia for initial pain management, particularly when severe pain recurs during their stay in the emergency department. Patients with a similar clinical profile to those in the PASTIES studies are most likely to benefit; however, extrapolation to other groups is not unreasonable, particularly when a second bolus of intravenous opiate is being considered,” Dr. Lecky said.

She concluded, “We know that PCA devices are safe and effective in the postoperative setting, where they have been used extensively since the 1990s. Cost effectiveness—although not described in PASTIES—is unlikely to be a major barrier for emergency departments, as the small investment in reusable equipment and set-up time is more than likely to be recuperated by reductions in the nursing time spent administering additional bolus opiates. The acronym for the PCA device should perhaps be reattributed to ‘patient centered analgesia,’ as these devices clearly deliver an autonomy that is highly valued by many patients.”

Dr. Smith told Reuters Health, “As a result of the findings of these trials, we have instituted a PCA protocol for use in our emergency department, and hope that other emergency departments will follow suit and add this to the armory of analgesia options available to emergency physicians.”

The PASTIES studies were funded by the National Institute for Health Research. The authors and Dr. Lecky have no disclosures.