- Aortocaval compression
- From 20 weeks the gravid uterus reduces venous return in the supine position by up to 30-40%
- Respiratory
- Changes in lung function, diaphragmatic splinting, decreased Functional Residual Capacity and increased oxygen consumption make ventilation more difficult and hypoxia more rapid.
- Intubation
- Increased breast size, laryngeal odema and weight gain in pregnancy can make intubation more difficult. Along with an increased risk of aspiration due to a progesterone mediated decrease in Lower Oesophageal Sphincter tone and increased intra-abdominal pressure.
- Cardiovascular
- Increased plasma volume by up to 50% causes dilutional anaemia. Decreased Systemic Vascular Resistance and increased Heart Rate and Cardiac Output increases circulation demands. Uterine blood flow is approximately 10% of Cardiac Output at term resulting in potential for massive haemorrhage.
This patient experienced a major placental abruption with associated severe concealed antepartum haemorrhage. She had risk factors including increasing age, smoking and pre-eclampsia. Following emergency delivery of the fetus to control bleeding she is taken to intensive care for ongoing management of hypovolaemic shock, coagulopathy and pre-eclampsia.
