Renal and systemic hemodynamics, in falciparum malaria

Renal and systemic hemodynamics, plasma arginine vasopressin, plasma renin activity, plasma norepinephrine, blood volume and water loading test were studied in 10 patients with falciparum malaria without renal failure. Six patients responded to water load normally, while 4 patients had a decreased response to water load. The patients with a normal water load response had normal renal and systemic hemodynamics and a normal hormonal profile. The patients with a decreased response to water load had hyponatremia, hypervolemia, high cardiac index, low systemic vascular resistance, high plasma arginine vasopressin, high plasma renin activity, high plasma norepinephrine, low creatinine and p-aminohippurate clearances, low urine sodium and high urine osmolality. They had a lower mean arterial pressure during the acute phase of the disease than during the recovery phase. The findings suggest that a decreased response to water load is due to peripheral vasodilatation which results in a decreased effective blood volume leading to the release of vasopressin and norepinephrine, increased renin activity and decreased renal hemodynamics.