Leong 2015.

Methods	Safety study with single‐group assignment investigating vital‐sign patient‐assisted intravenous analgesia with remifentanil. The study is not yet recruiting. The author's origin is Singapore. Trial identifier: NCT02733835
Participants	Inclusion criteria: patients who choose to use parenteral opioid for pain relief, written informed consent, refuse labour epidural analgesia, contraindication to epidural analgesia, gestational age ≥ 36 weeks. Exclusion criteria: inability to understand instructions or to self‐administer PCA boluses, language differences, hypersensitivity to remifentanil or any component of its formulation or to other fentanyl analogue, severe respiratory disease, history of drug dependence or recreational drug abuse, unmanaged fetal bradycardia.
Interventions	patient‐assisted IV remifentanil
Outcomes	The primary outcome is maternal desaturation. The secondary outcomes are apnoea/hypopnoea and maternal bradycardia.
Notes	This study is expected to be excluded (no control intervention).