Continuous is not continuous: the incidence and impact of circuit "down-time" on uraemic control during continuous veno-venous haemofiltration

• DOI: 10.1007/s00134-003-1672-8
• Publication Date: 2016-03-29T21:55:55Z
• Authors: Shigehiko Uchino; Nigel Fealy; Ian Baldwin; Hiroshi Morimatsu; Rinaldo Bellomo
• Keywords: Hemofiltration; Renal replacement therapy

There is little information on the duration of time that patients spend off therapy (down-time) during continuous veno-venous haemofiltration (CVVH) and the effect of this treatment free time on azotaemic control.Prospective observational study in the ICU of tertiary hospital.48 critically ill patients treated with CVVH at 2 l/h of ultrafiltration.Prospective collection of demographic and biochemical data.Two hundred and sixty-six filters were observed. Start and end times were collected for each filter. Creatinine and urea were measured daily and percentage of reduction of these two solutes was calculated (%Delta creatinine and urea). The median period when CVVH was not applied to a patient (down-time) was 3 h per day. There was a significant inverse correlation between down-time and %Delta creatinine and urea over each 24-h time cycle. On average at least 16 h per day of CVVH was required to maintain creatinine and urea concentration for each 24-h cycle."Continuous" therapy is not truly continuous. Down-time adversely affects azotaemic control. Physicians prescribing CRRT should be aware of the consequences of such down-time on the quality and quantity of renal replacement therapy delivered.