USE OF THE VALSALVA MANEUVER TO IDENTIFY HEMODIALYSIS-PATIENTS AT RISK OF CONGESTIVE-HEART-FAILURE

Background, In the presence of elevated cardiac filling pressures, the decline of blood pressure (BP) during the straining phase of a Valsal va manoeuvre is blunted or absent. We compared the use of non-invasive ly measured BP response to a Valsalva manoeuvre with clinical assessme nt and bioimpedance measurements to identify haemodialysis patients at risk of acute congestive heart failure (CHF). Methods, Continuous BP response (Finapres) to a Valsalva manoeuvre, clinical assessment by ne phrologists, and bioimpedance estimations of extracellular fluid volum e were determined before and after haemodialysis, once every week duri ng a 5-week period. Acute CHF was defined according to preset clinical and radiological criteria. Results. Participants (age 60 +/- 19 years , six females, nine males) had an average predialysis weight of 66.8 /- 11.8 kg. Patients were dialysed for 3.8 +/- 0.8 h with a mean ultra filtration of 2.4 +/- 1.1 litres. Valsalva systolic BP ratios (phase 2 to 1) decreased significantly during dialysis from 0.81 +/- 0.11 to 0 .73 +/- 0.10 (P < 0.05). Five patients experienced an episode of acute CHF. The Valsalva BP ratios for these patients before and after dialy sis (0.89 +/- 0.05 and 0.78 +/- 0.05 respectively) were higher than fo r the remaining ten patients (0.77 +/- 0.10 and 0.70 +/- 0.11, respect ively) (P < 0.05). A cutoff Valsalva BP ratio of 0.82 resulted in posi tive and negative predictive values for CHF of 62 and 100% respectivel y. No differences in clinical assessment or bioimpedance parameters we re found, with the exception of postdialysis diastolic BP and predialy sis ankle oedema. After treatment of CHF, Valsalva BP ratios decreased significantly without changes in the other hydration parameters. Conc lusions. Non-invasive assessment of the BP response to a Valsalva mano euvre appears to be a potential tool for identifying patients at risk of acute CHF during maintenance haemodialysis.