Prolonged Daily Intermittent Renal Replacement Therapy in ICU Patients by ICU Nurses and ICU Physicians

Abstract

Objectives Prolonged daily intermittent renal replacement therapy (PDIRRT) has been proposed as a new form of treatment for severe acute renal failure (ARF). However, this treatment has so far implied a) full dependence on nephrological input, b) lack of any convective clearance and c) limited purification of dialysate water. The aim of this study was to establish the feasibility and safety of performing PDIRRT in the ICU with a) no nephrological input, b) the addition of some convective clearance with on-line fluid replacement and c) a new advanced water purification system. Design Prospective observational study. Patients Fourteen patients treated with PDIRRT. Setting ICU of tertiary institution. Interventions Treatment of patients with severe ARF and critical illness with PDIRRT. Prescription of treatment by ICU physicians. Conduct of treatment by ICU nurses. Use of combined convective and diffusive therapy with on-line generation of fluid replacement, application of a double-filtration water purification system. Measurements and Main Results We prospectively collected demographic, biochemical, hemodynamic and clinical data in 14 patients, who received 30 PDIRRT treatments for a cumulative treatment time of 205.4 hours. The mean age was 57.9 ± 16.0. Eight patients were male and 6 female. Their mean APACHE II score was 24.6 ± 5.9 and their SAPS II score was 41.7 ± 18.8. PDIRRT was used after at least 24 hours of initial stabilization with continuous veno-venous hemofiltration (CVVH). Blood flow was kept at 100ml/min dialysate flow at 200 ml/min and convective clearance varied from 21 ml/min to 33 ml/min. All patients were either anuric or oliguric (UO < 400 ml/day). Ten patients were on mechanical ventilation and 11 patients on vasopressor support. Mean treatment session time was 6.9 ± 1.8 hours. The mean pre-PDIRRT urea was 19.2 ± 6.9 mmol/L and the creatinine was 274 ± 116 μmol/L. The mean pre-PDIRRT lactate was 2.95 ± 2.24 mmol/L. Following treatment, all had significantly decreased to 13.2 ± 6.3 mmol/L, 215 ± 95 μmol/L and 2.25 ± 1.61 mmol/L, respectively (p=<0.0001, <0.0001, <0.05). Bicarbonate levels remained stable during treatment (23.0 ± 3.8 mmol/L to 23.1 ± 2.5 mmol/L). Mean norepinephrine dose changed from 8.8 ± 11.9 μg/min to 12.9 ± 27.0 μg/min after treatment (NS). There were no complications of therapy. Patient ICU survival was 71.4%. Conclusions PDIRRT with combined diffusive and convective clearance is an efficacious form of renal replacement, which can be safely and effectively conducted by ICU nurses following prescription by ICU physicians without any nephrological involvement and with adequate double filtration water purification.