title: Predilution hemofiltration. Clinical experience and removal of small molecular weight solutes.
abstract: Over 1500 treatments of hemofiltration with on-line preparation of substitution fluid were performed in 16 patients. Two patients were treated for over 40 months. On-line preparation of the solution allowed use of bicarbonate as a buffer. 73-74 L/session were infused in pre-dilution modality, at a rate of about 370 ml/min, and the treatment length was above 4 hrs. The good quality of on-line prepared solution was confirmed by the negativity of microbiological tests and by the absence of clinical or sub-clinical reactions in patients. Urea clearance was calculated by equations considering either plasma flow or whole blood flow. Results were 196-197 ml/min and 186-183 ml/min, respectively. The latter was nearer to the value of directly measured clearance (182-173 ml/min). Kt/V urea was about 1 per session and PCR ranged between 1.3 and 1.4 g/kg/day. A high vascular stability was also observed. Since sodium balance may, at least in part, account for better vascular stability, sodium sieving coefficient was measured during the treatment. The sodium-retaining effect of the increase of protein concentration within the filter, due to the ultrafiltration, was less relevant in pre-dilution hemofiltration if compared to post-dilution hemofiltration. It has been calculated that to obtain a sodium balance similar to that of the hemodialysis (HD), the sodium concentration of infusion solution should be about 2 mEq/L higher than HD dialysis solution. However, difficulty in performing accurate balance studies prevents a general agreement on these conclusions.
authors.affiliation: Department of Nephrology, University of Parma, Italy.
authors.forename: S
authors.initials: S
authors.lastname: David
authors.forename: M
authors.initials: M
authors.lastname: Boström
authors.forename: V
authors.initials: V
authors.lastname: Cambi
mesh_terms: D000085:Acetates / Q000097:blood; D001639:Bicarbonates / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D002712:Chlorides / Q000097:blood; D004573:Electrolytes / Q000097:blood*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006339:Heart Rate / Q000502:physiology; D006440:Hemofiltration / Q000592:standards*; D006801:Humans; D008274:Magnesium / Q000097:blood; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009862:Online Systems; D011188:Potassium / Q000097:blood; D006435:Renal Dialysis / Q000592:standards; D012964:Sodium / Q000097:blood; D016896:Treatment Outcome; D014508:Urea / Q000097:blood; D014882:Water-Electrolyte Balance
chemical_list: D000085:Acetates; D001639:Bicarbonates; D002712:Chlorides; D004573:Electrolytes; D014508:Urea; D012964:Sodium; D008274:Magnesium; D005947:Glucose; D011188:Potassium