| Methods |
2‐arm active‐controlled double‐dummy randomised trial |
| Participants |
60 women were randomised in a hospital setting in Canada. The population comprised women of any parity, a singleton pregnancy, at high risk for PPH, who delivered by elective caesarean section. Exclusion criteria comprised women with heart disease or cardiac arrhythmia, hypertension or liver/renal/endocrine disease. |
| Interventions |
100 mcg of carbetocin administered by an IV bolus versus 32.5 IU of oxytocin administered by an IV bolus + infusion |
| Outcomes |
The study recorded the following outcomes: PPH at 500; PPH at 1000; additional uterotonics; transfusion; death; blood loss (mL); nausea; vomiting; headache; fever; shivering; abdominal pain. |
| Notes |
Contact with study authors for additional information: yes. Additional data from authors: no |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Sequence generation was not reported. |
| Allocation concealment (selection bias) |
Unclear risk |
Allocation concealment was not reported. |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
Study participants and caregivers were blinded to treatment allocations. |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
Double‐blinded. |
| Objective assessment of blood loss |
Low risk |
Investigators appraised blood loss by a sensitive colorimetric measurement of the Hb concentration of blood loss collected, quote: "by means of aspiration from the operative field [that] began immediately after administration of the study drug and ceased at the time of skin closure. All gauzes used during this timeframe were placed in 15% Lyse solution. All aspirated blood, gauzes, and the reference blood sample were sent to the laboratory for quantification of total blood volume. Blood on gauzes was extracted with Lyse solution, and haemoglobin content was determined with a sensitive colorimetric method adapted to the Cobas FARA analyser. Haemoglobin concentration is proportional to the absorbance of a hydrogen peroxide‐activated aminophenazone‐phenol mixture measured at a wavelength of 500 nm. The inter‐assay coefficient of variation averaged 3.3%, and the limit of detection of the assay was 14 mg/dL. The amount of blood collected in gauzes was calculated with the following formula: blood loss in dL = amount of haemoglobin in surgical gauzes in mg/haemoglobin concentration in mg/dL before caesarean section. Total blood loss was calculated by means of summing the volumes of blood aspirated and collected with gauzes". |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Quote: "3 patients who received general instead of epidural anaesthesia were excluded from the study and did not receive the study medication" but the study report did not specify whether these exclusions occurred before or after randomisation. |
| Selective reporting (reporting bias) |
Unclear risk |
The protocol of the study was unavailable for verification. |
| Intention to treat analysis |
High risk |
Those who withdrew from the study after randomisation were not included in the analysis. |
| Funding source |
High risk |
The study was supported by funding from Ferring Pharmaceuticals. |
