The effects of cremophor EL in the anaesthetized dog

Abstract

The effects of cremophor EL were studied in 13 anaesthetized, paralyzed and ventilated dogs. Twenty per cent cremophor EL in a dose of 4.3 ± 0.92 ml was infused at a rate of 30 ml · hr-1. In seven dogs, thoracopulmonary compliance, heart rate, systemic arterial pressure (SAP), pulmonary pressures (PAP, PCWP, RAP), cardiac output (CO) and platelet and white cell counts, were measured before the injection of cremophor EL, at the end of infusion and 5,10, 30 and 150 minutes after the end of infusion. In six dogs, SAP, CO, and blood volume were measured before the injection of cremophor EL, at the end of infusion and 10, 30, 90 and 150 minutes after the end of infusion. Plasma histamine and catecholamines were assayed before the injection of cremophor EL and 2, 5, 10, 30, 90 and 150 minutes after starting the infusion. Cremophor EL induced a marked, sustained and significant decrease in SAP at the end of infusion and at 5, 10 and 30 minutes after the completion of the infusion (-68, -71, -70 and -43 per cent respectively), in PCWP, RAP and CO (-78 per cent at the end of infusion, -32 per cent 150 minutes after the end of infusion). Heart rate and systemic vascular resistance did not vary significantly. Pulmonary vascular resistance increased at the end of infusion, five and ten minutes after the end of infusion ( + 734, +548 and +439 per cent respectively). Plasma volume decreased 10 and 30 minutes after the end of infusion (-28 and -30.5 per cent respectively). Thoracopulmonary compliance decreased (-46 per cent at the end of infusion). Platelet and white cell counts decreased markedly. There was a marked and sustained increase in plasma hista mine (+ 1214 per cent 10 minutes after start of infusion) and in plasma epinephrine and norepinephrine. In six dogs cutaneous erythema and oedema of the paws and of the muzzle were present. These findings are very similar to the observations reported in man during anaphylactoid and/or anaphylactic reactions. This model could be used in studying anaphylactoid reactions and their prevention and treatment. © 1987 Canadian Anesthesiologists.