Plasma catecholamines in renal failure

Continuous Renal Replacement Therapy for Pheochromocytoma Crisis With Multiple Organ Failure

Pheochromocytoma crisis is a feared and potentially lethal complication associated with excess release of catecholamine from the tumor, which might lead to multiple organ failure (MOF). The definitive treatment for pheochromocytoma is surgical resection. To safely proceed with surgery, hemodynamic stabilization in the acute phase is indispensable, but it might be extremely challenging in case of pheochromocytoma crisis with MOF even if the sufficient pharmacological drugs would be administered. Catecholamine is a dialyzable substance and is removed by renal replacement therapy. In this report, we described 2 cases of pheochromocytoma crisis with MOF, in which we succeeded in controlling acute unstable hemodynamics by means of catecholamine removal with continuous renal replacement therapy. These cases suggest that continuous renal replacement therapy may be effective to manage unstable hemodynamics because of massive catecholamine excretion in patients with pheochromocytoma crisis and MOF.

Sympathetic overactivity in patients with chronic renal failure

BACKGROUND

Hypertension is a frequent complication of chronic renal failure, but its causes are not fully understood. There is indirect evidence that increased activity of the sympathetic nervous system might contribute to hypertension in patients with end-stage renal disease, but sympathetic-nerve discharge has not been measured directly in patients or animals with chronic renal failure.

METHODS

We recorded the rate of postganglionic sympathetic-nerve discharge to the blood vessels in skeletal muscle by means of microelectrodes inserted into the peroneal nerve in 18 patients with native kidneys who were undergoing long-term treatment with hemodialysis (of whom 14 had hypertension), 5 patients receiving hemodialysis who had undergone bilateral nephrectomy (of whom 1 had hypertension), and 11 normal subjects. RESULTS. The mean (+/- SE) rate of sympathetic-nerve discharge was 2.5 times higher in the patients receiving hemodialysis who had not undergone nephrectomy than in the normal subjects (58 +/- 3 vs. 23 +/- 3 bursts per minute, P < 0.01). In contrast, the rate of sympathetic-nerve discharge was similar in the patients receiving hemodialysis who had undergone bilateral nephrectomy (21 +/- 6 bursts per minute) and the normal subjects. The rate of sympathetic-nerve discharge in the patients receiving hemodialysis who had not undergone nephrectomy was also significantly higher (P < 0.01) than that in the patients with bilateral nephrectomy, and it was accompanied in the former group by higher values for vascular resistance in the calf (45 +/- 4 vs. 22 +/- 4 units, P < 0.05) and mean arterial pressure (106 +/- 4 vs. 76 +/- 14 mm Hg, P < 0.05). The rate of sympathetic-nerve discharge was not correlated with either plasma norepinephrine concentrations or plasma renin activity.

CONCLUSIONS

Chronic renal failure may be accompanied by reversible sympathetic activation, which appears to be mediated by an afferent signal arising in the failing kidneys.