Has mortality from acute renal failure decreased? A systematic review of the literature Yvonne Patricia Ympa MD a , Yasser Sakr MBBCh, MSc b , Konrad Reinhart MD, PhD b and Jean-Louis Vincent MD, PhD a , , a Department of Intensive Care, Erasme Hospital, Free University of Brussels, Belgium b Department of Anesthesia and Intensive Care, Friedrich Schiller University, Jena, Germany Available online 8 August 2005. Abstract Purpose To determine mortality rates in patients with acute renal failure during the past decades. Methods We performed a MEDLINE search using the keywords “acute renal failure” crossed with “outcome,” “mortality,” “ICU,” “critically ill” or “prognosis” in the period from January 1970 to December 2004. Abstracts and full articles were eligible if mortality rates were reported. We also reviewed the bibliographies of available studies for further potentially eligible studies. The dates of the observation period for each study and not the publication dates were considered for the analysis, so the earliest data were from 1956. Results Of 85 articles fulfilling the criteria, 5 were excluded because of duplicate publications using the same database, so that 80 were included in our review with a total of 15 897 patients. Mortality rates in most studies exceeded 30%, and there was no consistent change over time. Conclusion Despite technical progress in the management of acute renal failure over the last 50 years, mortality rates seem to have remained unchanged at around 50%.
Though vascular etiologies are generally prerenal like to separate them out from the usual algorithm above in order to not miss such diagnoses – renal artery stenoses and more ominously dissections or thromboses or emboli
Predialysis weight predicts Kt/V Interestingly, the major determinant of the Kt/V urea was the pre-dialysis weight. What that tells us -- and that is for both prescribed and delivered dose of dialysis - this tells us that we prescribe dialysis for our acute patients based more on logistics than on the patient that is in front of us. We tend to be limited by nursing staff availability and other procedures the patient may be going through, so we tend to prescribe a fixed dose of dialysis in terms of time, in terms of maximal achievable blood flow, no matter whether the patient in front of us weighs 50 kg or the patient in front of us weighs 100 kg, and no matter what the urea generation rate is of our patient.
Patients were randomly assigned ultrafiltration at 20 mL h(-1) kg(-1) (group 1, n=146), 35 mL h(-1) kg(-1) (group 2, n=139), or 45 mL h(-1) kg(-1) (group 3, n=140). The primary endpoint was survival at 15 days after stopping haemofiltration
Daily dialysis in ARF This was attempted to be exploited by a study published in The New England Journal by Dr. Schiffl with 172 patients; 160 randomized to daily dialysis versus every other day dialysis.
Equivalent renal urea clearance The issue that has come up lately in this is particularly relevant both in patients with end-stage renal disease and in patients with acute renal failure is that in addition to the intensity of a given dialysis session, the frequency with which your patient receives dialysis will make a substantial difference in the amount of solute clearance. Casino and Lopez published a number of years ago a concept for equivalent renal urea clearance. Dr. Gotch has done something similar with a standardized Kt/V urea. The concept is still the same with either type of format and that is that since removal of a solute such as urea is exponential during dialysis, most of the removal of the solute occurs relatively early in any given dialysis session when there is a greater concentration gradient from the blood to the dialysate So as one strives for ever greater Kt/V, let us say, in a given dialysis session one is proportionately removing less and less total amount of solute. So you will get more total solute removal by having frequent sessions, even at less individual intensity. For example here if we have an individual session Kt/V of 0.8 but we dialyze this patient seven times a week, we have an EKR clearance of 20 cc/minute per week. Whereas another patient if we choose to dialyze very intensively for a given session, let us say out here 1.8, but we only dialyze that patient two or three times a week, we will actually have less clearance. So you get much more solute clearance with increasing the frequency than necessarily with increasing the intensity of a given dialysis session. Nephrol Dial Transplant. 1996 Aug;11(8):1574-81. Related Articles, Links The equivalent renal urea clearance: a new parameter to assess dialysis dose. Casino FG, Lopez T. Department of Nephrology and Dialysis, Ospedale Civile, Matera, Italy. BACKGROUND: Currently the total (dialytic plus renal) urea clearance (KT) is computed as Kt/V plus the equivalent Kt/V (KT/VKR) provided by the renal urea clearance (KR). However, KT/VKR is computed with two different formulae, by Gotch and Keshaviah respectively. Moreover Teschan suggested a weekly KT, that is a multiple of Keshaviah's KT. We suggest the equivalent renal urea clearance (EKR), that kinetically quantifies the &quot;time-averaged KT' and is independent of treatment type and schedule. METHODS: Computer simulation has been used to analyse the relationship between EKR, as corrected for urea volume (EKRc), and Kt/V. Data from 66 HD patients, of whom eight were on once-weekly and 11 on twice-weekly HD, had been used to compare EKR with current KTs. RESULTS: For each individual schedule, the relationship between EKRc and Kt/V is linear and each ml/min of KR increases EKR by the same amount. For instance, for thrice-weekly HD patients, EKRc = 1 + 10 x Kt/V: so that, the critical Kt/V values of 0.8 and 1.0 correspond to EKRc values of 9.0 and 11 ml/min respectively, independently from treatment type and schedule. As to the clinical data, all once- and twice-weekly patients had a significant KR and excellent clinical status, but most of them had 9 < or = EKRc < 11 ml/min. After appropriate reconciliation of units, it has been found that kinetic KT was overestimated by about 10-12% (range, 2-23%) by Keshaviah and Teschan's KT, and by about 2-7% (range, 0.3-15%) by Gotch's KT. CONCLUSIONS: EKRc can account for KR and provide guidelines for all types of dialysis treatments: as far as urea is concerned, dialysis adequacy should require EKRc > or = 11 ml/min. However, it is likely that EKRc > or = 9 ml/min could suffice for patients with a substantial residual renal function.
Prevention and Management of Acute Renal Failure C. John Sperati, M.D. Division of Nephrology Johns Hopkins University SOM [email_address]