The canine kidney in haemorrhagic shock: effect of verapamil

Recent evidence suggests that verapamil administration reduces myocardial and small intestinal damage in canine haemorrhagic shock, and verapamil has also been shown to reduce renal dysfunction in clamp models in post-ischaemic renal failure. The effects of high-dose verapamil and hypovolaemia on renal haemodynamics and function in a canine haemorrhagic shock model were studied. Anaesthetized mongrel dogs were divided into three groups. Animals of group I (n = 5) were not subjected to shock but given a 90-min verapamil infusion (2.28 micrograms/kg); animals of group II (n = 5) were subjected to shock (mean blood pressure 40 mm Hg) for 2 h and given a 90-min 0.9% saline infusion, and animals of group III (n = 7) were both subjected to a 2-hour shock and given verapamil. The electrocardiograph was monitored, and general haemodynamic parameters were measured before shock (period 1), at the end of shock (period 2), after reinfusion of shed blood (period 3) and 1 h after shock (period 4). Total renal and cortical zonal blood flow was estimated by radioactively labelled microsphere injection during each period. Creatinine and osmolar clearance were estimated before and after shock. Verapamil administration caused heart block in groups I and III which lowered heart rate and blood pressure and exacerbated the haemodynamic effects of shock in group III. Despite this, no measurable difference in renal function was recorded between groups II and III. Total renal blood flow fell during shock, and this was exacerbated in animals given verapamil, suggesting a cumulative deleterious effect of shock and verapamil in renal blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)