Sodium Bicarbonate Versus Sodium Chloride for Preventing Contrast-Associated Acute Kidney Injury in Critically Ill Patients: A Randomized Controlled Trial.

OBJECTIVES: To test whether hydration with bicarbonate rather than isotonic sodium chloride reduces the risk of contrast-associated acute kidney injury in critically ill patients. DESIGN: Prospective, double-blind, multicenter, randomized controlled study. SETTING: Three French ICUs. PATIENTS: Critically ill patients with stable renal function (n = 307) who received intravascular contrast media. INTERVENTIONS: Hydration with 0.9% sodium chloride or 1.4% sodium bicarbonate administered with the same infusion protocol: 3 mL/kg during 1 hour before and 1 mL/kg/hr during 6 hours after contrast medium exposure. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the development of contrast-associated acute kidney injury, as defined by the Acute Kidney Injury Network criteria, 72 hours after contrast exposure. Patients randomized to the bicarbonate group (n = 151) showed a higher urinary pH at the end of the infusion than patients randomized to the saline group (n = 156) (6.7 ± 2.1 vs 6.2 ± 1.8, respectively; p < 0.0001). The frequency of contrast-associated acute kidney injury was similar in both groups: 52 patients (33.3%) in the saline group and 53 patients (35.1%) in the bicarbonate group (absolute risk difference, -1.8%; 95% CI [-12.3% to 8.9%]; p = 0.81). The need for renal replacement therapy (five [3.2%] and six [3.9%] patients; p = 0.77), ICU length of stay (24.7 ± 22.9 and 23 ± 23.8 d; p = 0.52), and mortality (25 [16.0%] and 24 [15.9%] patients; p > 0.99) were also similar between the saline and bicarbonate groups, respectively. CONCLUSIONS: Except for urinary pH, none of the outcomes differed between the two groups. Among ICU patients with stable renal function, the benefit of using sodium bicarbonate rather than isotonic sodium chloride for preventing contrast-associated acute kidney injury is marginal, if any.

Diagnostic accuracy of hemoconcentration for pulmonary edema as the cause of weaning failure.

BACKGROUND: Our objective was to assess the diagnostic accuracy of hemoconcentration for cardiogenic pulmonary edema (PE) as the cause of weaning failure, using left ventricular filling pressure elevation assessed by transthoracic echocardiography as the reference standard. METHODS: This prospective observational study included 41 patients who failed their first spontaneous breathing trial of weaning from mechanical ventilation. They were divided into two groups, with and without PE by echocardiographic criteria. Hemoconcentration and other hemodynamic parameters were compared between the groups. RESULTS: The group (N.=21) with PE by echocardiographic criteria had a higher frequency of failure of the second spontaneous breathing trial (P=0.03) and a longer total weaning time (P=0.02) compared to the other group. The receiver-operating characteristics curve indicated that changes in plasma protein or hemoglobin concentration from initiation to completion of the second spontaneous breathing trial did not predict PE as the cause of failure (areas under the receiver-operating characteristics curve, 0.47±0.09 and 0.51±0.09, respectively). The only factor predicting failure due to PE was a positive fluid balance from intensive care unit admission to study inclusion (P=0.01). The increase in mean arterial blood pressure seemed suggestive of weaning failure due to cardiac causes. CONCLUSIONS: Compared to echocardiographic criteria for left ventricular filling pressure elevation, hemoconcentration assessed based on plasma protein and hemoglobin levels did not help to diagnose cardiogenic PE as the cause of weaning failure.

Intravascular Complications of Central Venous Catheterization by Insertion Site.

BACKGROUND: Three anatomical sites are commonly used to insert central venous catheters, but insertion at each site has the potential for major complications. METHODS: In this multicenter trial, we randomly assigned nontunneled central venous catheterization in patients in the adult intensive care unit (ICU) to the subclavian, jugular, or femoral vein (in a 1:1:1 ratio if all three insertion sites were suitable [three-choice scheme] and in a 1:1 ratio if two sites were suitable [two-choice scheme]). The primary outcome measure was a composite of catheter-related bloodstream infection and symptomatic deep-vein thrombosis. RESULTS: A total of 3471 catheters were inserted in 3027 patients. In the three-choice comparison, there were 8, 20, and 22 primary outcome events in the subclavian, jugular, and femoral groups, respectively (1.5, 3.6, and 4.6 per 1000 catheter-days; P=0.02). In pairwise comparisons, the risk of the primary outcome was significantly higher in the femoral group than in the subclavian group (hazard ratio, 3.5; 95% confidence interval [CI], 1.5 to 7.8; P=0.003) and in the jugular group than in the subclavian group (hazard ratio, 2.1; 95% CI, 1.0 to 4.3; P=0.04), whereas the risk in the femoral group was similar to that in the jugular group (hazard ratio, 1.3; 95% CI, 0.8 to 2.1; P=0.30). In the three-choice comparison, pneumothorax requiring chest-tube insertion occurred in association with 13 (1.5%) of the subclavian-vein insertions and 4 (0.5%) of the jugular-vein insertions. CONCLUSIONS: In this trial, subclavian-vein catheterization was associated with a lower risk of bloodstream infection and symptomatic thrombosis and a higher risk of pneumothorax than jugular-vein or femoral-vein catheterization. (Funded by the Hospital Program for Clinical Research, French Ministry of Health; ClinicalTrials.gov number, NCT01479153.).

Accuracy of plasma neutrophil gelatinase-associated lipocalin in the early diagnosis of contrast-induced acute kidney injury in critical illness.

PURPOSE: Neutrophil gelatinase-associated lipocalin (NGAL) is a promising biomarker for acute kidney injury (AKI). We evaluated the diagnostic and prognostic accuracies of plasma NGAL (pNGAL) for contrast-induced AKI (CI-AKI) in critically ill patients. METHODS: In a prospective observational study in two adult intensive care units in a university hospital, 100 consecutive critically ill patients with stable serum creatinine concentrations up to 48 h before contrast medium (CM) injection were enrolled. Serial blood sampling for pNGAL analysis was performed at enrolment, 2, 6, and 24 h after CM injection. The primary outcome was CI-AKI, defined by AKIN criteria, within the first 72 h following CM injection. Secondary outcomes were the need for renal replacement therapy (RRT) and mortality. RESULTS: Of the 98 patients analyzed, 30 developed CI-AKI. The pNGAL levels did not differ in patients with or without CI-AKI, and were higher in septic patients compared to nonseptic patients, and in patients with AKI preceding CM injection. The discriminative value of pNGAL to predict CI-AKI and mortality was poor; although, it did predict the need for RRT requirement after CM injection (area under receiver-operating characteristic curve, 0.85, 0.80, 0.83 and 0.86 at H0, H2, H6 and H24, respectively). CONCLUSION: CI-AKI was common in critically ill patients. pNGAL levels were higher in patients with sepsis or previous AKI, but did not help to diagnose CI-AKI any earlier than serum creatinine after CM injection. However, pNGAL could be of interest to detect patients at risk of subsequent RRT requirement.

Overview of adverse events related to invasive procedures in the intensive care unit.

BACKGROUND: This study was conducted to determine the frequency, predictors, and clinical impact of adverse events (AEs) related to invasive procedures in the intensive care unit (ICU). METHODS: This was a prospective observational study of ICUs in a university hospital. RESULTS: A total of 893 patients requiring invasive procedures were admitted over a 1-year period. Among these, 310 patients (34.7%) experienced a total of 505 AEs. The mean number of AEs per patient was 1.6 ± 1.1 (range, 1-7). Infectious AEs were significantly more frequent than mechanical AEs (60.4% vs 39.6%; P = .01). Factors independently associated with AE occurrence were isolation of multidrug-resistant bacteria at ICU admission, >5 invasive procedures, and ICU length of stay >8 days. Thirty-three AEs (6.5%) resulted in severe clinical impact, including 24 deaths. Ventilator-associated pneumonia (VAP) accounted for 62.5% of the deaths related to AEs. CONCLUSIONS: One-third of critically ill patients experienced AEs related to invasive procedures. Severe AEs were associated with 11% of all ICU deaths. VAP was the most frequent AE related to death. An improved assessment of the risk-benefit balance before each invasive procedure and increased efforts to decrease VAP prevalence are needed to reduce AE-related mortality.