Patient-Controlled Analgesia More Effective Than Standard Care

Results from two trials published in BMJ suggest that patient-controlled analgesia (PCA) appears to be statistically and clinically superior to standard pain control in emergency department (ED) patients with non-traumatic abdominal pain. Pain relief for patients with traumatic injury-related pain experienced similar outcomes with standard care and PCA.

Whereas patients presenting to the ED with moderate or severe pain are typically provided intravenous morphine administered by a nurse, and although this approach is usually safe and effective in the short term, it is demanding on nursing time, especially when repeat doses are required.

PCA devices consist of a syringe usually containing morphine that can be connected to a drip in the patient’s arm, allowing them to deliver their own pain relief by pressing a button. The devices have been commonly used in post-surgical patients, but little was known about their use in ED patients. Little evidence exists to support PCA use in the emergency setting, and no studies had assessed its effectiveness in the hours following admission to the ward, until now.

The two randomized controlled trials—conducted by research teams, funded by the UK’s National Institute of Health Research, from Plymouth Hospitals National Health Service (NHS) Trust and Plymouth University Peninsula Schools of Medicine and Dentistry, and managed by the Peninsula Clinical Trials Unit at Plymouth University, England—addressed this knowledge gap by assessing PCA in the ED and following admission in patients with non-traumatic abdominal pain and pain from traumatic injury.

For both trials, 200 patients were included who had presented to the ED with moderate to severe pain and were expected to be admitted to the hospital for at least 12 hours. Routine care was based on the best current practice using various modes of analgesia according to NHS trust analgesia policy.

Among patients who presented with abdominal pain, PCA users reported an average total pain score of 35.3, compared with a score of 47.3 for those who received usual pain relief. For patients with traumatic injury-related pain, those using PCA reported an average total pain score of 44.0, compared with a score of 47.2 for those who received usual pain relief. However PCA patients with traumatic injury-related pain who used PCA were nearly twice as likely to be very or perfectly satisfied with their treatment when compared with patients who received routine care.

“We were surprised that these two studies produced quite different results, but there are several possible reasons that have subsequently been suggested,” said lead author Jason Smith, Consultant in Emergency Medicine at Plymouth Hospitals NHS Trust and Professor of Emergency Medicine at Plymouth University Peninsula Schools of Medicine and Dentistry.

“Other factors may be important in patients with traumatic injuries, such as the effect of splinting on limb injuries… Notwithstanding, my take on this is that in emergency patients who are in pain (either abdominal pain or pain from traumatic injuries), PCA should be considered as a possible treatment option, particularly in patients whose pain is difficult to manage. We have, on the back of the results of these studies, set up a clinical protocol for the use of PCA in emergency patients at Plymouth Hospitals NHS Trust.”