Fluid balance and urine volume are independent predictors of mortality in acute kidney injury.

INTRODUCTION: In ICUs, both fluid overload and oliguria are common complications associated with increased mortality among critically ill patients, particularly in acute kidney injury (AKI). Although fluid overload is an expected complication of oliguria, it remains unclear whether their effects on mortality are independent of each other. The aim of this study is to evaluate the impact of both fluid balance and urine volume on outcomes and determine whether they behave as independent predictors of mortality in adult ICU patients with AKI. METHODS: We performed a secondary analysis of data from a multicenter, prospective cohort study in 10 Italian ICUs. AKI was defined by renal sequential organ failure assessment (SOFA) score (creatinine >3.5 mg/dL or urine output (UO) <500 mL/d). Oliguria was defined as a UO <500 mL/d. Mean fluid balance (MFB) and mean urine volume (MUV) were calculated as the arithmetic mean of all daily values. Use of diuretics was noted daily. To assess the impact of MFB and MUV on mortality of AKI patients, multivariate analysis was performed by Cox regression. RESULTS: Of the 601 included patients, 132 had AKI during their ICU stay and the mortality in this group was 50%. Non-surviving AKI patients had higher MFB (1.31 ± 1.24 versus 0.17 ± 0.72 L/day; P <0.001) and lower MUV (1.28 ± 0.90 versus 2.35 ± 0.98 L/day; P <0.001) as compared to survivors. In the multivariate analysis, MFB (adjusted hazard ratio (HR) 1.67 per L/day, 95%CI 1.33 to 2.09; <0.001) and MUV (adjusted HR 0.47 per L/day, 95%CI 0.33 to 0.67; <0.001) remained independent risk factors for 28-day mortality after adjustment for age, gender, diabetes, hypertension, diuretic use, non-renal SOFA and sepsis. Diuretic use was associated with better survival in this population (adjusted HR 0.25, 95%CI 0.12 to 0.52; <0.001). CONCLUSIONS: In this multicenter ICU study, a higher fluid balance and a lower urine volume were both important factors associated with 28-day mortality of AKI patients.

RIFLE-based data collection/management system applied to a prospective cohort multicenter Italian study on the epidemiology of acute kidney injury in the intensive care unit.

The epidemiology of acute kidney injury (AKI) has been difficult to explore in the past, due to different definitions across various studies. Nevertheless, this is a very important topic today in light of the high morbidity and mortality of critically ill patients presenting renal dysfunction during their stay in the intensive care unit (ICU). The case mix has changed over the years, and AKI is a common problem in critically ill patients often requiring renal replacement therapy (RRT). The RIFLE and AKIN initiatives have provided a unifying definition for AKI, making possible large retrospective studies in different countries. The present study aims at validating a unified web-based data collection and data management tool based on the most recent AKI definition/classification system. The interactive database is designed to elucidate the epidemiology of AKI in a critically ill population. As a test, we performed a prospective observational multicenter study designed to prospectively evaluate all incident admissions in ten ICUs in Italy and the relevant epidemiology of AKI. Thus, a simple user-friendly web-based data collection tool was created with the scope to serve for this study and to facilitate future multicenter collaborative efforts. We enrolled 601 consecutive incident patients into the study; 25 patients with end-stage renal disease were excluded, leaving 576 patients for analysis. The median age was 66 (IQR 53-76) years, 59.4% were male, while median Simplified Acute Physiology Score II and Acute Physiology and Chronic Health Evaluation II scores were 43 (IQR 35-54) and 18 (IQR 13-24), respectively. The most common diagnostic categories for ICU admission were: respiratory (27.4%), followed by neurologic (17%), trauma (14.4%), and cardiovascular (12.1%). Crude ICU and hospital mortality were 21.7% and median ICU length of stay was 5 (IQR 3-14) days. Of 576 patients, 246 patients (42.7%) had AKI within 24 h of ICU admission, while 133 developed new AKI later during their ICU stay. RIFLE-initial class was Risk in 205 patients (54.1%), Injury in 99 (26.1%) and Failure in 75 (19.8%). Progression of AKI to a worse RIFLE class was seen in 114 patients (30.8% of AKI patients). AKI patients were older, with higher frequency of common risk factors. 116 AKI patients (30.6%) fulfilled criteria for sepsis during their ICU stay, compared to 33 (16.7%) of non-AKI patients (p < 0.001). 48 patients (8.3%) were treated with RRT in the ICU. Patients were started on RRT a median of 2 (IQR 0-6) days after ICU admission. AKI patients were started on RRT a median of 1 (IQR 0-4) day after fulfilling criteria for AKI. Median duration of RRT was 5 (IQR 2-10) days. AKI patients had a higher crude ICU mortality (28.8 vs. 8.1%, non-AKI; p < 0.001) and longer ICU length of stay (median 7 vs. 3 days, non-AKI; p < 0.001). Crude ICU mortality and ICU length of stay increased with greater severity of AKI. 225 (59.4% of AKI patients) had complete recovery of renal function, with a serum creatinine at time of ICU discharge which was ≤120% of baseline; an additional 51 AKI patients (13.5%) had partial renal recovery, while 103 (27.2%) had not recovered renal function at the time of death or ICU discharge. The study supports the use of RIFLE as an optimal classification system to stage AKI severity. AKI is indeed a deadly complication for ICU patients, where the level of severity is correlated with mortality and length of stay. The tool developed for data collection was user-friendly and easy to implement. Some of its features, including a RIFLE class alert system, may help the treating physician to systematically collect AKI data in the ICU and possibly may guide specific decisions on the institution of RRT.

Risk factors and outcome of Acinetobacter baumanii infection in severe trauma patients.

OBJECTIVE: To investigate incidence, risk factors and outcome of Acinetobacter baumanii infection in trauma patients. DESIGN AND SETTING: A retrospective analysis of prospectively collected data of all trauma patients admitted to a general intensive care unit (ICU) of a 1,500-bed university hospital over 3 years. PATIENTS: Three hundred thirty trauma patients were included in the study. RESULTS: Thirty-six (10.9%) cases of A. baumanii infection were observed; 29 of them were late onset pneumonia. Patients with A. baumanii infection had a significantly higher Injury Severity Score (ISS) (p = 0.02), a lower Glasgow Coma Scale (GCS) on ICU admission (p = 0.03), stayed longer in the ICU (p = 0.00001), were mechanically ventilated for a longer period of time (p = 0.00001), were more frequently admitted to the emergency department with hypotension (p = 0.02), and had trans-skeletal traction for more than 3 days (p = 0.003) in comparison to the 294 patients who did not develop A. baumanii infection. At multivariate analysis the time spent on mechanical ventilation (p = 0.02) and the presence of long-term trans-skeletal traction (p = 0.04) were the only independent risk factors for A. baumanii infection. Patients with A. baumanii infection had a high mortality rate (9 out of 36; 25.0%). ISS (p = 0.003), GCS (p = 0.001) and older age (p = 0.00001), but not A. baumanii infection (p = 0.15), were independently correlated with mortality. CONCLUSIONS: In trauma patients prolonged mechanical ventilation and delayed fracture fixation with the persistence of trans-skeletal traction were major risk factors for A. baumanii infection. The presence of this infection was not correlated with mortality.

Percutaneous translaryngeal versus surgical tracheostomy: A randomized trial with 1-yr double-blind follow-up.

OBJECTIVE: To compare the outcomes and the short- and long-term complications of percutaneous translaryngeal tracheostomy (TLT) and surgical tracheostomy (ST). DESIGN: Prospective, randomized clinical trial with 1-yr double-blind follow-up. SETTING: A general intensive care unit of a university hospital. PATIENTS: A total of 139 consecutive critically ill patients who required a tracheostomy between February 2001 and June 2002 were randomly assigned to receive either ST or TLT. RESULTS: TLTs were performed more rapidly than STs (17 +/- 10 mins vs. 22 +/- 6 mins, p = .003). Early complications were rare in both groups. Major postoperative bleeding was less frequent with TLT (0 [0%] vs. 6 [8%], p = .03). Only one case of bleeding (in the ST group) required blood transfusion. Immediately after tracheostomy, six TLT patients (9%) and six patients (8%) in the ST group (p = .56) developed culture-confirmed bacteremia with microbes previously isolated from the pharynx or trachea. Group rates for stomal infections and pneumonia after tracheostomy were similar. At 1-yr follow-up, the overall survival rate was 27%, and 14 patients (45% of survivors) still had open tracheostomies. Both groups rated their quality of life as moderately to severely compromised, and the deterioration was strictly related to the presence of tracheostomy. One TLT and two ST survivors (p = .53) had clinical signs of tracheal stenosis, and bronchoscopy revealed narrowing of >50%. CONCLUSIONS: Compared with ST, the main advantages of TLT are that it is more rapid and associated with less postoperative bleeding. Infectious complications, particularly postoperative bacteremia, and long-term effects (physical and emotional) are similar with the two procedures.

Fiberoptic bronchoscopy during noninvasive positive pressure ventilation delivered by helmet.

OBJECTIVE: To evaluate the feasibility and safety of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) during noninvasive positive pressure ventilation (NPPV) delivered by helmet in patients with acute respiratory failure (ARF) and suspected pneumonia. DESIGN AND SETTING: Prospective, clinical investigation in a general intensive care unit (ICU) of a university hospital. PATIENTS AND PARTICIPANTS: Four adult patients with ARF who underwent NPPV via the helmet and required fiberoptic BAL for suspected pneumonia. INTERVENTIONS: NPPV was delivered through the helmet in the pressure support ventilation mode. The specific seal connector placed in the plastic ring of the helmet allowed the passage of the bronchoscope, maintaining assisted ventilation. Arterial blood gas levels, pH, oxygen saturation, respiratory rate, heart rate, and mean arterial blood pressure were monitored during the study. RESULTS: Helmet NPPV avoided gas exchanges deterioration during FOB and BAL, with good tolerance. During the procedure heart rate increased by 5% and mean arterial blood pressure by 7% over baseline; these levels returned to prebronchoscopic values immediately after the withdrawal of the bronchoscope. Endotracheal intubation was never required during the 24 h after the procedure. BAL yielded diagnostic information in three of four patients. CONCLUSIONS: NPPV through the helmet allows a safe diagnostic FOB with BAL in patients with hypoxemic ARF, avoiding gas exchange deterioration, and endotracheal intubation. ELECTRONIC SUPPLEMENTARY MATERIAL: is available if you access this article at http://dx.doi.org/10.1007/s00134-002-1554-5. On that page (frame on the left side), a link takes you directly to the supplementary materials.