Table 1

Exclusion criteria

Patients over 75 yearsAltered plasma levels of opioid in this age group for a given standard dose of PCA
Patients with a reduced conscious level (Glasgow Coma Score <15)Will not be able to give informed consent
Inability to operate a PCA deviceWill not be able to complete the intervention
Patients who cannot understand the study informationFor example due to pre-existing dementia, learning difficulties or intoxication. Will not be able to give informed consent
Patients with chronic painAltered pain processing or opioid tolerance
Patients who are opioid tolerant or have active opioid addictionAbnormal response to opioids or potential opioid misuse
Patients with a history of renal failureAccumulation of active opioid metabolites
Allergy or other contraindication to morphine
Hypotension (systolic blood pressure <90 mmHg)Morphine may exacerbate hypotension
Patients in police custody, or prisoners
Inability to gain intravenous accessWill not be able to receive intravenous morphine
Patients who are likely to be definitively treated in the ED and discharged, or who are likely to require transfer for surgery direct from the EDWill not be able to complete 12 h of VAS scoring
Patients who are pregnant or breast-feedingAltered drug metabolism and fetal/infant opioid effects
Patients on other predetermined analgesia pathwayeg, regional anaesthesia
Previous participation in this study
Current participation in another CTIMP
  • CTIMP, clinical trial of an investigational medicinal product; ED, emergency department; PCA, patient controlled analgesia, VAS, visual analogue scale.