|Participants||n = 45.|
|Interventions||Group 1 received room air, group 2 received oxygen 6 L/min and group 3 received oxygen 10 L/min via simple face mask.|
Pre-load: lactated Ringer's solution 1.500-2,000 mL; and
Epidural anaesthesia: 18-20 mL of 2% xylocaine with adrenaline 1:200,000 via epidural catheter.
Maternal ABG (pH, PO2, PCO2, HCO3, base excess, saturation) at the time of delivery.
Fetal UV and UA (pH, PO2, PCO2, HCO3, base excess, saturation) analysis at the time of delivery.
Number of foetuses with Apgar scores < 7 at 1, 5 min.
|Notes||Theoretically delivered oxygen:|
Group 1 = 21%.
Group 2 = 40%.
Group 3 = 60%.
|Risk of bias|
|Bias||Authors' judgement||Support for judgement|
|Random sequence generation (selection bias)||High risk||"They were allocated randomly to the following 3 groups; breathing room air (group 1, control, breathing through a simple face mask with oxygen inflow of 6 L/min or (group 2) breathing through a simple face mask with oxygen inflow of 10 L/min".|
Comment: no randomization description and in the results stated: "Forty-five participants were divided equally into 3 groups in the study".
|Allocation concealment (selection bias)||High risk||Not described.|
|Blinding of participants and personnel (performance bias) |
|High risk||Blinding of those receiving care: not stated.|
Blinding of those providing care: not stated.
Comment: participants, staff and research personnel probably unblinded to the intervention, since group 1 breathing room air, groups 2 and 3 breathing through a simple face mask.
|Blinding of outcome assessment (detection bias) |
|Low risk||Blinding of outcome assessors: yes (paediatrician who assessed Apgar scores).|
"The 1- and 5-minute Apgar scores were awarded by a paediatrician unaware of the maternal inspired oxygen concentration".
|Incomplete outcome data (attrition bias) |
|High risk||More than one reported outcome was not pre-specified. Recruitment and attrition data absent.|
|Selective reporting (reporting bias)||High risk||"We were interested in knowing (1) whether such a method of delivering oxygen to the mother could improve foetal oxygenation in our current practice and (2) whether foetal PO2 could be increased by an increment of oxygen flow to the simple face mask".|
Comment: More than one reported outcome was not pre-specified.
|Other bias||High risk||No data support the following statement: "In our study, a simple O2 mask was used to deliver oxygen to the patient......The oxygen percentages delivered through the simple mask can approach 35% to 55% when oxygen flow rates of 6 L to 10 L/min are used for adults".|
The actual FIO2 of the intervention group was not reported. The data were entered as FIO2 of 0.4 (for oxygen 6 L/min) and 0.6 (for oxygen 10 L/min) for analysis. Sample size calculation not stated.