Patients gain only slight benefits from controlling their own analgesia
Patient-controlled analgesia (PCA) may be no more effective at controlling moderate to severe pain than routine care, according to a randomised controlled trial in English hospitals.
A total of 200 adults participated in the study. They presented to the emergency department requiring intravenous analgesia and admission to hospital with either traumatic musculoskeletal injury or non-traumatic abdominal pain.
Patients use more pain relief than clinicians would usually administer
Participants allocated to receive routine care were treated with intravenous morphine while in the emergency department and oral morphine (or subcutaneous/intramuscular morphine for those nil by mouth) when transferred to the ward. Participants in the PCA group received instruction by the research nurse in how to operate the PCA device.
The primary outcome was total pain experienced over the 12-hour study period.
There was slight – but not statistically significant – lower total pain in the PCA group than in the routine care group.
However, the researchers ‘cannot rule out the possibility that PCA provides a clinical benefit’.
They wrote: ‘Significantly more morphine was used in the PCA group, which may reflect under-treatment in the routine care group. Patients’ satisfaction also showed a difference in favour of PCA; the difference did not reach statistical significance, although it may be clinically important.’