Ngan Kee 2000.
| Study characteristics | ||
| Methods | RCT | |
| Participants | 80 women Inclusion criteria: ASA I or II Asian women with term singleton pregnancies having elective CS Exclusion criteria: pre‐existing or pregnancy‐induced hypertension, known cardiovascular or cerebrovascular disease, or contraindications to spinal anaesthesia Setting: Hong Kong, China |
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| Interventions |
Ephedrine + crystalloid preload (different doses) versus crystalloid preload alone Group1: ephedrine 10 mg Group 2: ephedrine 20 mg Group 3: ephedrine 30 mg Group 4: saline control All were diluted to 10 mL with saline and injected intravenously over 30 s. All women received a standardised crystalloid preload with Ringer's lactate followed by a standardised spinal anaesthetic technique and dose. |
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| Outcomes |
Maternal: hypotension; hypertension; heart rate; total ephedrine dose; nausea or vomiting; upper sensory level; skin incision to birth and uterine incision to birth time Neonatal: Apgar scores at 1 min and 5 min; umbilical arterial and venous blood gas and pH; cardiotocograph |
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| Notes | Hypotension defined as SBP < 80% baseline or < 100 mmHg Hypertension defined as SBP > 120% baseline |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Coded, opaque shuffled envelopes – randomisation method not described |
| Allocation concealment (selection bias) | Low risk | Adequate: coded, opaque shuffled envelopes, study drugs were prepared by an anaesthetist not involved in assessing women |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Double‐blind (participants and anaesthetists) – no further details |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | As above |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Losses to follow‐up: maternal heart rate data lost in 1 woman (out of 20) from 10 mg group; cord blood samples incomplete in 2 each from control (n = 20), 20 mg (n = 20) and 30 mg (n = 20) groups |
| Selective reporting (reporting bias) | Low risk | Appears to report all outcomes |
| Other bias | Low risk | None evident |