Validation of the inverse method for the determination of the access flow with thermodilution.

INTRODUCTION: Thermodiluction is a widely used method for measuring vascular access flow (QA). Among the possibilities of TD, the reverse method (MI) can be beneficial in the execution time, without impact on the dialysis efficacy (Kt). However, it is not a sufficiently studied technique. METHOD: Transversal study of 117 arteriovenous fistulas (AVF). Two QA measurements were taken with the method described by the manufacturer (MR) and another with MI. MI is bases in the obtention of an inverted recirculation registry at the beginning of the session and a single subsequent recirculation measurement with the lines in normal position. In the concordance analysis, the Bland-Altman method and Cohen's Kappa index were used. RESULTS: Very good concordance between MR and MI was evidenced for QA below 700 ml/min, but it worsens as flow increases. The median variability between the MR measurements (intra-method variability) was 3.4% (-17.13). This value did not differ from the median variability generated between MR and MI (inter-method variability), which was 2% (-14, 12) (P = 0.287). The degree of agreement between the two to identify AVFs susceptible to intervention was very good (K = 0.834). The time spent using the MI was significantly shorter (P = 0.000) without evidence of variations in the Kt of the measurement sessions (P = 0.201). CONCLUSIONS: The thermodiluction MI is valid to determine the flow of the vascular access, especially in Qa lower than 700 ml/min, with great time savings, simplification of the procedure and without modifying the dialysis efficiency. The variability between the measurement by MR and MI is similar to that of MR. The concordance between methods in identifying potentially pathological AVFs is very good.

Evaluation of the impact of an intradialytic exercise programme on sarcopaenia in very elderly haemodialysis patients.

Sarcopaenia is a highly prevalent condition in persons on haemodialysis (HD). In stable very elderly (75-95 years old) persons on chronic HD, we prospectively studied the European Working Group on Sarcopaenia in Older People (EWGSOP2) steps stability over time in 37 controls and their response to a 12-week intradialytic lower limb exercise programme in 23 persons. Overall dropout was 15% and the main cause for dropout was death (8%). Thus 33 controls and 18 exercise participants were evaluated at 12 weeks. In controls, comorbidity, nutrition, dependency and frailty scales, anthropometric assessments, EWGSOP2 step values and the prevalence of suspected, confirmed and severe sarcopaenia as assessed by EWGSOP2 remained stable. In contrast, in persons who completed the exercise programme, a significant improvement in the five times sit-to-stand (STS-5) test was noted at the end of the 12-week exercise programme (19.2 ± 4.9-15.9 ± 5.9 seconds; P = .001), consistent with the lower limb nature of the exercise programme, that persisted 12 weeks after completion of the programme. Exercise also improved the Fried frailty scale (1.7 ± 1.0-1.1 ± 0.6; P = .004). In conclusion, EWGSOP2 steps remain stable in stable very elderly persons on HD and STS-5 is responsive to a short-term intradialytic lower limb exercise programme. These results may help define EWGSOP2-based primary endpoints in future large-scale clinical trials assessing exercise interventions.