Table 2.

Monitoring and technical considerations in pregnant and non-pregnant patients. MFM, Maternal Fetal Medicine.

Monitoring

•Arterial catheter: upper extremity, right-sided if femoral or left axillary VA ECMO. •Central venous catheter: ideally above the diaphragm. •Fetal heart monitoring: daily or continuous depending on gestational age, MFM and institutional recommendations. •Uterine tocodynamometry: assessment for uterine contractions based on clinical scenario.

Technical issues

•Aortocaval compression from gravid uterus (>20 weeks of gestation)—consider uterine displacement 15–30° for cannulation and to maintain adequate flow. •Pao2 goal ≥9.5 kPa for fetal perfusion. •Paco2 goal 4.0–4.3 kPa for fetal acidosis.

Delivery considerations

• Gestational age: ○ Before viability and 28 weeks: no evidence that termination of pregnancy will improve maternal outcomes. ○ 28–32 weeks: the mechanical respiratory changes of pregnancy and fetal oxygen consumption may increase burden on maternal oxygenation. There is some evidence that delivery may improve Pao2 and airway pressures in pregnant patients with ARDS. However, it does not reduce duration of mechanical ventilation or need for ECMO. ○ Beyond 32 weeks: the fetal risk and maternal benefit of delivery is supported by expert consensus and if safe and feasible, may be pursued. • Method of delivery: no data to support one mode over another in these patients ○ Vaginal/assisted vaginal/Caesarean. ○ Prior obstetric history and cervical examination taken into account for potential induction of labour. ○ Greater risk of haemorrhage with Caesarean delivery.