Читать книгу Managing Medical and Obstetric Emergencies and Trauma - Группа авторов - Страница 135

There is a decrease in arteriolar and venous tone. This causes venous pooling of blood and a drop in vascular resistance, resulting in hypotension. In the initial stages of sepsis, there is hypotension with reduced cardiac output and low filling pressures. With fluid resuscitation, cardiac output increases, resulting in a hyperdynamic circulation, but there is not much change in blood pressure owing to a reduced vascular resistance. There is an increase in pulmonary vascular resistance, resulting in raised pulmonary arterial pressures. The changes in the vascular tone differ in different vascular beds, resulting in the maldistribution of blood volume and flow. There is evidence to suggest that the ability of tissues to extract oxygen is impaired owing to mitochondrial dysfunction. This encourages anaerobic metabolism in tissues, promoting lactic acidosis.