Prognosis of acute renal failure: an evaluation of proposed consensus criteria.

OBJECTIVES: To validate the recently proposed criteria for acute renal injury (ARI), acute renal failure syndrome (ARFS) and severe acute renal failure syndrome (SARFS) and to evaluate the significance of other prognostic factors. DESIGN AND SETTING: Retrospective analysis of the Riyadh ICU Program database of patients admitted to 22 ICUs in UK and Germany between 1989 and 1998. PATIENTS: Included in the study were 41,972 patients, of whom 7,522 (17.9%) had ARI, 2,641 (6.3%) had ARFS and 1,747 (4.2%) had SARFS. RESULTS: Patients with ARI, ARFS or SARFS had a hospital mortality of 29.5%, 49.2% or 63.0%, respectively, compared to 10.3% among patients without acute renal failure. In the presence of contemporaneous failure of any other organs on the day of acute renal failure, hospital mortality increased to 73.3%, 76.2%, 72.1% and 18%, respectively. Multivariate analysis showed that non-surgical admission, need for emergency surgery, development of acute renal failure during stay in ICU, need for mechanical ventilation and the number of other failed organ systems had a greater impact on prognosis than the need for renal replacement therapy. CONCLUSIONS: The proposed criteria for ARI, ARFS and SARFS correlated with mortality, but other factors had a greater impact on prognosis. Renal replacement therapy did not increase the risk of hospital mortality among patients with acute renal failure.

Coma mimicking brain death following baclofen overdose.

Baclofen toxicity can be a cause of profound coma with brainstem dysfunction mimicking brain death, and is mainly a clinical diagnosis. Measuring plasma levels is not always possible and may be misleading. Imaging results are usually normal. Electroencephalography may show a pattern of burst suppression. At present no effective specific therapy is available. However, as demonstrated in our case, the prognosis can be good even in severe cases, provided it is recognized early enough, and appropriate supportive measures are instituted.

Acute renal failure following cardiopulmonary bypass: a changing picture.

OBJECTIVE: To assess the incidence of acute renal failure (ARF) developing perioperatively in adult patients requiring cardiopulmonary bypass surgery (CPB) and to make comparisons with data from the same institution published earlier. DESIGN: Prospective, observational. SETTING: Tertiary referral centre for cardiopulmonary medicine. PATIENTS AND PARTICIPANTS: All patients admitted to the intensive care unit (ICU) who developed ARF perioperatively necessitating continuous veno-venous haemofiltration (CVVH) during the 24 months January 1997-December 1998. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Of 2337 adult patients undergoing cardiac surgery, 47 (2.0%) needed CVVH. Patients were excluded from analysis who underwent cardiac transplantation (n = 4), pericardial surgery (n = 3) or insertion of a left ventricular assist device (n = 1). Of the remaining 39, 21 patients died in ICU (53.8% mortality). Relatively more non-survivors suffered from diabetes, hypertension and preoperative renal dysfunction. A previous report from our Unit revealed that, in 1989-90, 2.7% of all patients undergoing CPB required CVVH with an in-hospital mortality of 83%. The current study population were older (65.3 vs 56.0 years in 1990), and more severely ill as evidenced by a higher percentage of patients requiring redo (30% vs 8.6% in 1990) and emergency (50% vs 25.7% in 1990) surgery. CONCLUSIONS: The need for CVVH following CPB may be diminishing despite increased risk factors. ARF-associated mortality in these circumstances is falling.

Sedation in the intensive care unit: a systematic review.

CONTEXT: Sedation has become an integral part of critical care practice in minimizing patient discomfort; however, sedatives have adverse effects and the potential to prolong mechanical ventilation, which may increase health care costs. OBJECTIVE: To determine which form of sedation is associated with optimal sedation, the shortest time to extubation, and length of intensive care unit (ICU) stay. DATA SOURCES: A key word search of MEDLINE, EMBASE, and the Cochrane Collaboration databases and hand searches of 6 anesthesiology journals from 1980 to June 1998. Experts and industry representatives were contacted, personal files were searched, and reference lists of relevant primary and review articles were reviewed. STUDY SELECTION: Studies included were randomized controlled trials enrolling adult patients receiving mechanical ventilation and requiring short-term or long-term sedation. At least 2 sedative agents had to be compared and the quality of sedation, time to extubation, or length of ICU stay analyzed. DATA EXTRACTION: Data on population, intervention, outcome, and methodological quality were extracted in duplicate by 2 of 3 investigators using 8 validity criteria. DATA SYNTHESIS: Of 49 identified randomized controlled trials, 32 met our selection criteria; 20 studied short-term sedation and 14, long-term sedation. Of these, 20 compared propofol with midazolam. Most trials were not double-blind and did not report or standardize important cointerventions. Propofol provides at least as effective sedation as midazolam and results in a faster time to extubation, with an increased risk of hypotension and higher cost. Insufficient data exist to determine effect on length of stay in the ICU. Isoflurane demonstrated some advantages over midazolam, and ketamine had a more favorable hemodynamic profile than fentanyl in patients with head injuries. CONCLUSION: Considering the widespread use of sedation for critically ill patients, more large, high-quality, randomized controlled trials of the effectiveness of different agents for short-term and long-term sedation are warranted.

Lipid profiles in patients with atherosclerotic renal artery stenosis.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is an important cause of renal disease in the elderly, and these patients have a high morbidity and mortality. There are no data on their blood lipid profiles. METHODS: The lipoprotein profiles were examined in patients with proven ARAS and compared with patients matched for age, gender, renal function and presence of diabetes. RESULTS: The profiles did not show any significant difference for apolipoprotein B (control 1.31 +/- 0.39 vs. ARAS 1.24 +/- 0.28; mean +/- SD), cholesterol (control 5.65 +/- 1.28 vs. ARAS 6.12 +/- 1.29), LDL cholesterol (control 3.72 +/- 1.03 vs. ARAS 4.06 +/- 1.18), fibrinogen (control 2.48 +/- 1.39 vs. ARAS 3.29 +/- 1.49), HDL cholesterol (control 1.16 +/- 0.38 vs. ARAS 1.00 +/- 0.26) and triglyceride (control 1.68 +/- 0.80 vs. ARAS 2.32 +/- 1.73) levels between the groups. Surprisingly lipoprotein(a) levels were higher in the control group (0.58 +/- 0.45) vs. ARAS (0.31 +/- 0.21). The most striking abnormality was the markedly lower apolipoprotein A1 levels in the ARAS group (control 2.09 +/- 0.55 vs. ARAS 0.95 +/- 0. 30) and apolipoprotein A1/B ratio (control 1.74 +/- 0.71 vs. ARAS 0. 78 +/- 0.24). CONCLUSION: The lipoprotein abnormality in ARAS mirrors that in other severe vascular diseases. Potential therapeutic interventions in patients with ARAS should consider treatments to modify the apolipoprotein A1 concentration rather than cholesterol alone.