Renal replacement therapy continuous

Dosing of Selected Intravenous Anti-Infectives in Patients Receiving Continuous Renal Replacement Therapy... 

Continuous renal replacement therapy is used for the management of fluid overload and removal of uremic toxins in patients with acute renal failure and other conditions. Drug therapy individualization for patients receiving continuous renal replacement therapy is discussed in Chap. 75. 

Bohler J, Donauer J, Keller F. Pharmacokinetic principles during continuous renal replacement therapy drugs and dosage. Kidney Int 1999 72 Suppl S24-8. 

Five patients with metformin-associated severe lactic acidosis, seen between 1 September 1998 and 31 May 2001, have been reported (58). Two had attempted suicide. All had severe metabolic acidosis with a high anion gap and raised blood lactate concentrations. Four developed profound hypotension and three had acute respiratory failure. Three had normal preceding renal function. Three required conventional hemodialysis and two continuous renal replacement therapy. 

PATIENTS RECEIVING CONTINUOUS RENAL REPLACEMENT THERAPY... 

Preprinted order set design Hypokalemia Sliding scale insulin Continuous renal replacement therapy... 

Hemofiltration is a prominent feature of many continuous renal replacement therapies (Table 6.2). How-ever continuous hemodialysis can also be employed to accelerate solute removal (16). The contribution of both processes to extracorporeal drug clearance will be considered separately in the context of continuous renal replacement therapy. 

In contrast with intermittent hemodialysis in which dialyzer blood flow is rate limiting/ diffusive drug clearance during continuous renal replacement therapy is limited by dialysate flow (Qd)/ which typically is only 25 mL/min. Accordingly/ diffusive drug clearance (CLd) is calculated from the equation ... 

Extracorporeal clearance during continuous renal replacement therapy (CLpc) can be regarded as the sum of convective and hemodialytic clearance (16/ 31) ... 

By analogy with Equation 6.6/ the contribution of CLec to total solute clearance during continuous renal replacement therapy is given by... 

Drug doses need to be increased or supplemented for patients requiring renal replacement therapy only if CLec/ representing extracorporeal clearance from either intermittent hemodialysis or continuous renal replacement therapy/ is substantial when compared to CLr + CLjVR (Equation 6.12). Levy (34) has proposed that supplementation is needed only when CLec is greater than 30% of CL + CLjvr- Several approaches will be considered that can be used to make appropriate drug dose adjustments for patients requiring renal replacement therapy. 

A second approach is to calculate supplemental doses to replace drug lost during hemodialysis or continuous renal replacement therapy by directly measuring drug loss by extracorporeal removal or by... 

A third approach is to use the principles discussed previously to calculate a maintenance dose multiplication factor (MDMF) that can be used to augment the dose that would be appropriate in the absence of renal replacement therapy (32). For continuous renal replacement therapy, MDMF is given simply by the following ratio of clearances ... 

Ronco C, Bellomo R. Continuous renal replacement therapies The need for a standard nomenclature. Contrib Nephrol 1995 116 28-33. 

Golper TA, Marx MA. Drug dosing adjustments during continuous renal replacement therapies. Kidney Int 1998 53(suppl 66) S165-8. 

Schetz M, Perdinande P, Van den Berghe G, Verwaest C, Lauwers P. Pharmacokinetics of continuous renal replacement therapy. Intensive Care Med 1995 21 612-20. 

Reetze-Bonorden P, Bohler J, Keller E. Drug dosage in patients during continuous renal replacement therapy Pharmacokinetic and therapeutic considerations. Clin Pharmacokinet 1993 24 362-79. 

The pharmacokinetics of intravenous ciprofloxacin have been studied in intensive care unit patients during continuous venovenous hemofiltration (n — 5) or hemo-diafiltration (n — 5) (67). Ciprofloxacin clearance was not altered. A dosage of 400 mg/day was sufficient to maintain effective drug plasma concentrations in patients undergoing continuous renal replacement therapy. 

Malone RS, Fish DN, Abraham E, Teitelbaum I. Pharmacokinetics of levofloxacin and ciprofloxacin during continuous renal replacement therapy in critically iU patients. Antimicrob Agents Chemother 2001 45(10) 2949-54. 

Pittrow L, Penk A. Dosage adjustment of fluconazole during continuous renal replacement therapy (CAVH, CVVH, CAVHD, CVVHD). Mycoses 1999 42(1-2) 17-19. 

The utility of continuous renal replacement therapies (CRRT) such as continuous venous-venous hemodialysis (CWHD) in the treatment of poisoning is uncertain. As CRRT provides slower clearance than conventional hemodialysis it may not be appropriate for drug removal in acute intoxications [25]. However, the lower blood flow rates and longer treatment times of continuous modalities may be desirable for vulnerable, hemodynamically unstable, patients who are not candidates for conventional hemodialysis [7]. Unlike hemodialysis, CRRT can give effective clearances in hypotensive patients. If the clinical condition of the patient requires a low intensity treatment that will necessarily decrease diffusive clearance, slow extended dialysis (SLED) or continuous treatment times with additional convective clearance (CVVHF and CVVHDF) can likely provide adequate total drug clearance [24]. 

Goodman JW, Goldfarb DS. The role of continuous renal replacement therapy in the treatment of poisoning. Semin Dial. 

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