Carbetocin vs. oxytocin at elective caesarean delivery: a double-blind, randomised, controlled, non-inferiority trial of low- and high-dose regimens.

Carbetocin or oxytocin are given routinely as first-line uterotonic drugs following delivery of the neonate during caesarean delivery to prevent postpartum haemorrhage. Low doses may be as effective as high doses with a potential reduction in adverse effects. In this double-blind, randomised, controlled, non-inferiority trial, we assigned low-risk patients undergoing elective caesarean delivery under spinal anaesthesia to one of four groups: carbetocin 20 µg; carbetocin 100 µg; oxytocin 0.5 IU bolus + infusion; and oxytocin 5 IU bolus + infusion. The study drug was given intravenously after delivery of the neonate. Uterine tone was assessed by the obstetrician 2, 5 and 10 minutes after study drug administration according to an 11-point verbal numerical rating scale (0 = atonic, 10 = excellent tone). The primary outcome measure was uterine tone 2 min after study drug administration. The pre-specified non-inferiority margin was 1.2 points on the 11-point scale. Secondary outcomes included uterine tone after 5 and 10 minutes, use of additional uterotonics, blood loss and adverse effects. Data were available for 277 patients. Carbetocin 20 µg resulting in uterine tone of (median (IQR [range])) 8 (7-8 [1-10]) was non-inferior to carbetocin 100 µg with tone 8 (7-9 [3-10]), median (95%CI) difference 0 (-0.44-0.44). Similarly, oxytocin 0.5 IU with tone 7 (6-8 [3-10]) was non-inferior to oxytocin 5 IU with tone 8 (6-8 [2-10]), median (95%CI) difference 1 (0.11-1.89). Carbetocin 20 µg was also non-inferior to oxytocin 5 IU, and oxytocin 0.5 IU was non-inferior to carbetocin 100 µg. Uterine tone after 5 and 10 minutes, use of additional uterotonics, blood loss and adverse effects were similar in all groups.

Laparoscopic hepatectomy in a patient with uncontrolled polycythaemia vera.

This case report describes the peri-operative course of a patient with uncontrolled polycythaemia vera who underwent a laparoscopic hepatectomy for intrahepatic cholangiocarcinoma. Polycythaemia vera is a chronic condition that results in erythrocytosis and puts patients at risk of peri-operative complications including thrombotic events and paradoxical haemorrhage. Little evidence exists on the ideal peri-operative management of uncontrolled polycythaemia vera when the proposed procedure carries a high risk of haemorrhage. Our patient presented with a pre-operative haemoglobin of 197 g.l-1 (haematocrit 65%) and was not phlebotomised pre-operatively. Intra-operatively he lost 2700 ml of blood, reducing his haematocrit to 48%, and then suffered fatal thrombotic complications postoperatively. The patient did not receive any blood product transfusions during his peri-operative course. We review the available evidence to guide the peri-operative management of patients with polycythaemia vera. The inherent risks of thrombosis and haemorrhage associated with polycythaemia vera need to be weighed against the specific surgical and transfusion-related risks. Phlebotomy to achieve a pre-operative haematocrit under 45% is recommended and intra-operative phlebotomy shows promise for reducing blood loss during hepatectomies. Management of postoperative erythrocytosis may be an important and underappreciated aspect of reducing the peri-operative risk of thrombosis in patients with polycythaemia vera.