The Effects of Therapeutic Decrease in Packed Cell Volume on the Responses to Exercise of Patients with Polycythaemia Secondary to Lung Disease

Abstract

1. Progressive exercise and circulatory studies are reporteG on a selecteL group of patients with hypoxaemia and secondary polycythaemia before and after therapeutic decrease of packed cell volume.2. A significant increase in exercise tolerance was demonstrated in a group of seven patients who claimed subjective benefit from the treatment.3. No important circulatory changes were detected at rest after treatment. 4. During steady exercise mean pulmonary artery pressure at any given cardiac output was lower after treatment suggesting a fall in pulmonary vascular resistance. 5. During steady exercise oxygen consumption was increased in five of six patients subjectively improved by the treatment but no consistent changes in arterial lactate concentration or lactate/pyruvate ratio were observed.

Polycythemia of End-Stage Renal Failure: No Inhibition of Erythropoiesis by Uremic Serum and Markedly Increased Serum Erythropoietin Level

“…On the other hand, as Zappacosta et al [13] reported, the remnant kidneys in patients with end-stage renal disease must be able to produce, at least, normal amounts of EPO in order to overcome the unavoidable residual level of uremic toxins. In our case, the remnant kidneys might have also continued to produce this hormone due to chronic hy poxia [14], It is also possible that the high titer of EPO might have overcome the inhibitor produced in the uremic patient, because the erythropoietic activity in the serum, which has been assayed by means of FM LC assay, is expressed as the balance of stimulator and inhibitor. In addition, the patient was on CAPD, which could have reduced the inhibitor levels in serum.…”

Relationship between Erythropoietin Administration and the Endothelial Nitric Oxide Synthase Gene Polymorphism in Patients with Hemodialysis

“…However, it has been reported that the potential for Epo production is preserved in these patients, and that production is stimulated when pulmonary edema or hepatitis is present [1,2]. Circulatory insufficiency resulting from hypotension may be a potent stimulator of Epo production [probably due to the stimulation of the renin-angiotensin system or nitric oxide (NO) synthesis] even in patients with end-stage renal failure, because extrarenal Epo production is stimulated by renin or angiotensin [3][4][5].…”

Phlebotomy improves Pulmonary Gas Exchange in Chronic Mountain Polycythemia

“…On the other hand, there is not unanimous agreement between investigators upon the effects of bleeding on cardiopul monary function. Some reports show signifi cant changes in blood gases [18,20] and lung volumes [1,9] while others fail to de monstrate such changes [6,10,11,14,20,22,27]. However, all reports document im provement in the subjective feeling of well-being as well as the symptomatic relief experienced by COPD, CCHD and PV pa tients after phlebotomy [1, 6, 9-11, 14, 18, 20, 22, 27], Thus, blood-letting of a polycy themic patient is not an easy consideration except when thrombosis and bleeding are associated with polycythemia [25] or when symptomatic ischemic heart disease is asso ciated with erythrocytosis [2].…”