Transient versus persistent acute kidney injury and the diagnostic performance of fractional excretion of urea in critically ill patients.

AIMS: To evaluate the performance of fractional excretion of urea (FeU) for differentiating transient (T) from persistent (P) acute kidney injury (AKI) and to assess performance of FeU in predicting AKI in patients admitted to the ICU. METHODS: We performed secondary analysis of a multicenter prospective observational cohort study on the predictive performance of biological markers for AKI in critically ill patients. AKI was diagnosed according to RIFLE staging. RESULTS: Of 150 patients, 51 and 41 patients were classified as having T-AKI and P-AKI, respectively. The diagnostic performance for FeU to discriminate T-AKI from P-AKI on the day of AKI was poor (AUC-ROC = 0.61; 95% CI: 0.49-0.73). The diagnostic performance of FeU to predict AKI 1 and 2 days prior to AKI was poor as well (AUC-ROC = 0.61; 95% CI: 0.47-0.74, and 0.58; 95% CI: 0.43-0.73, respectively). CONCLUSIONS: FeU does not seem to be helpful in differentiating T- from P-AKI in critically ill patients and it is a poor predictor of AKI.

Bronchoalveolar Activation of Coagulation and Inhibition of Fibrinolysis during Ventilator-Associated Lung Injury.

Background and Objective. Bronchoalveolar coagulopathy is a characteristic feature of pulmonary inflammation. We compared bronchoalveolar and systemic levels of coagulation in patients who did and patients who did not develop ventilator-associated lung injury (VALI). Methods. Secondary analysis of a randomized controlled trial evaluating the effect of lower tidal volumes versus conventional tidal volumes in patients without acute lung injury or acute respiratory distress syndrome at the onset of mechanical ventilation. Results. Ten patients with VALI and 10 random control patients without lung injury during the course of mechanical ventilation, but all ventilated with conventional tidal volumes, were compared. Patients who developed VALI showed both bronchoalveolar activation of coagulation (increase in thrombin-antithrombin complex levels P < 0.001 versus baseline) and inhibition of fibrinolysis (decline in plasminogen activator activity P < 0.001 versus baseline). The later seemed to be dependent on higher levels of plasminogen activator inhibitor type 1 (P = 0.001 versus baseline). Patients who developed VALI also showed elevated systemic thrombin-antithrombin complex levels and decreased systemic plasminogen activator activity levels. Conclusions. VALI is characterized by bronchoalveolar coagulopathy. Systemic and bronchoalveolar coagulopathy at the onset of mechanical ventilation may be a risk factor for developing VALI in patients ventilated with conventional tidal volumes.

Catheter-related epidural abscesses -- don't wait for neurological deficits.

Epidural abscess is a rare but serious complication of epidural anesthesia for peri- and postoperative analgesia. It is feared because of possible persistent neurological deficits. Epidural abscess presents mostly with a classic triad of symptoms: back pain, fever and variable neurological signs and symptoms. When neurologic signs or symptoms develop, MRI scanning is the diagnostic procedure of choice. The therapy of choice is intravenous antibiotics for more than 4 weeks with or without a laminectomy or drainage. In the present paper we describe three patients with epidural abscesses presented during a time period of 1 year in our hospital. In each case, patients developed local signs of infection and systemic signs, but no neurological symptoms. Based on these cases and a review of the literature, we propose that MRI scanning should be strongly considered when patients present with systemic and local signs, even in the absence of neurological deficits.