RESUMO
Pulmonary hypertension may be either primary of unknown aetiology or secondary to existing cardio-respiratory disease. As a single entity the prognosis is poor but superimposition of the physiological changes of pregnancy and labour produces a lethal condition. This paper sets out two clinical cases of primary pulmonary hypertension as background for discussion to highlight the issues involved. Whatever this discussion does, let it be clearly spelled out that prevention is better than any proposed cure.
Assuntos
Hipertensão Pulmonar , Complicações Cardiovasculares na Gravidez , Adulto , Analgesia Obstétrica , Anestesia Obstétrica , Parto Obstétrico , Feminino , Humanos , Hipertensão Pulmonar/terapia , Recém-Nascido , Gravidez , Complicações Cardiovasculares na Gravidez/terapiaRESUMO
The haemodynamic effects of oxytocin on the pulmonary and systemic circulation were studied in six awake, pregnant (greater than 140 days gestation) ewes. Bolus doses of oxytocin 0.2 units/kg and then 0.8 units/kg were administered. A dose of 0.2 units/kg resulted in small but significant increases in mean pulmonary artery pressure (14%, P less than 0.05) and pulmonary vascular resistance (24%, P less than 0.05. A bolus of 0.8 units/kg resulted in a significant increase in mean arterial pressure (20%, P less than 0.05) and systemic vascular resistance (33%, P less than 0.05). Acute pulmonary hypertension was then induced with glass bead microemboli (150-200 microns), with an increase in pulmonary artery pressure of 26 mmHg and pulmonary vascular resistance of 448 dyn. s. cm-5. Boluses of oxytocin 0.2 and 0.8 units/kg were then administered. There were no significant changes, except for a 30% increase in systemic vascular resistance at one minute after oxytocin, 0.8 units/kg (P less than 0.05).