Randomized Evaluative Study of Phenylephrine Or Norepinephrine for maintenance of blood pressure during spinal anaesthesia for caesarean Delivery: the RESPOND study

INTERVENTION: Two groups:Norepinephrine versus Phenylephrine 30 min approximately; CONDITION: Pregnancy PRIMARY OUTCOME: Cardiac output 5 min after spinal injection; SECONDARY OUTCOME: Haemodynamic control ‐ intraoperatively;Umbilical cord blood gases – after delivery;Umbilical cord blood catecholamine concentrations – after delivery; INCLUSION CRITERIA: American Society of Anesthesiologists Physical Status 1 or 2 normotensive non‐labouring parturients with term singleton pregnancies who are scheduled for elective Caesarean section and who have been judged suitable and have agreed to have for spinal anaesthesia according to usual clinical criteria.