Effects of labetalol on uterine blood flow and cardiovascular hemodynamics in the hypertensive gravid baboon

Adrenergic receptor blockade attenuates placental ischemia-induced hypertension

Preeclampsia (PE), a disorder of new-onset maternal hypertension and vascular dysfunction during pregnancy, is thought to be linked to placental ischemia-induced release of prohypertensive factors and reductions of vasoprotective factors in the maternal circulation. Although markers of sympathetic nervous activity are elevated in experimental models of placental ischemia-induced hypertension and women with PE compared with their normal pregnant counterparts, the importance of adrenergic receptor signaling in the development of hypertension in PE is unknown. Therefore, we tested the hypothesis that adrenergic receptor blockade attenuates the development of placental ischemia-induced hypertension in rats. Wistar Hannover rats underwent reduced uterine perfusion pressure (RUPP) or Sham surgeries on gestational day 14. By day 19, mean arterial blood pressure (MAP) was increased in RUPP over Sham rats. Groups of RUPP and Sham pregnant rats received terazosin and propranolol (3 mg/kg per day of each via subcutaneous osmotic minipump) to block α1- and β-adrenergic receptors, respectively, beginning on gestational day 14. Adrenergic blockade significantly attenuated the development of hypertension in the RUPP rats with a slight blood pressure-lowering response in the Sham, normal pregnant rats by day 19. In conclusion, these data implicate that placental ischemia-induced hypertension involves adrenergic receptor signaling to promote increases in blood pressure during PE.

Maternal morbidity, mortality, and risk assessment

Maternal deaths in developed countries continue to decline and are rare. Maternal mortality statistics are essentially similar in the United States and United Kingdom. However, the situation is completely different in developing countries, where maternal mortality exceeds 0.5 million every year. This article not only assesses morbidity risks in some of the leading causes of maternal death but also highlights strategies to minimize the risks and to prevent maternal morbidity and mortality.

Anaesthesia and analgesia for the critically ill parturient

Anaesthetic and analgesic techniques in the critically ill are determined largely by the nature of the presenting illness. The commonest conditions likely to present as life-threatening emergencies are pre-eclampsia, obstetric haemorrhage, cardiac disease and severe sepsis. Issues dictating choice of anaesthetic technique are the patient's ability to maintain her airway, coagulation status, intravascular volume and haemodynamic dependence upon sympathetic drive, and requirements for ventilatory support and intensive care. Fetal well-being is an issue in the antepartum period, uteroplacental blood flow should be maintained and hypotension avoided. Maternal survival takes priority, however, and occasionally general anaesthetic techniques must be used which lead to neonatal respiratory depression and requirement for ventilatory support. Anaesthesia itself is associated with known hazards. The risks of each technique must be balanced against possible benefits in the context of the presenting illness.