Molecular analysis of endobronchial ultrasound needle aspirates in patients with non-small cell lung cancer: Results from the SCOPE database.

OBJECTIVE: Molecular subtyping of non-small cell lung cancer (NSCLC) is critical in the diagnostic evaluation of patients with advanced disease. This study aimed to examine whether samples from endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) of intrathoracic lymph nodes and/or lung lesions are adequate for molecular analysis across various institutions. METHODS: We retrospectively reviewed all cases of linear EBUS-TBNA with a final bronchoscopic diagnosis of NSCLC entered in the Stather Canadian Outcomes registry for chest ProcEdures database. The primary outcome was specimen inadequacy rate for each molecular target, as defined by the local laboratory or pathologist. RESULTS: A total of 866 EBUS-TBNA procedures for NSCLC were identified. Specimen inadequacy rates were 3.8% for EGFR, 2.5% for ALK-1 and 3.5% for PD-L1. Largest target size was not different between adequate and inadequate specimens, and rapid onsite evaluation did not increase specimen adequacy rates. One centre using next-generation sequencing for EGFR had lower adequacy rates than 2 others using matrix-assisted laser desorption/ionization time-of-flight mass spectrophotometry. CONCLUSION: EBUS-TBNA specimens have a very low-specimen inadequacy rate for molecular subtyping of non-small cell lung cancer.

Patient perspectives on the use of indwelling pleural catheters in malignant pleural effusions.

BACKGROUND: Indwelling pleural catheters are an effective treatment option for patients with malignant pleural effusions. Despite their popularity, there remains a paucity of data on the patient experience and key patient-centred outcomes. OBJECTIVE: To investigate the experience of patients receiving an indwelling pleural catheter to better inform and identify potential areas for improvement in care. METHODS: This was a multicentre survey study at three academic, tertiary-care centres in Canada. Patients with a diagnosis of malignant pleural effusion who had an indwelling pleural catheter inserted were included. An adapted questionnaire specific to indwelling pleural catheters was used with responses recorded on a 4-point Likert scale. Patients completed the questionnaire in-person or by phone at 2-week and 3-month follow-up appointments. RESULTS: A total of 105 patients were enrolled in the study with 84 patients included in the final analysis. At the 2-week follow-up, patient-reported improvements in dyspnoea and quality of life from indwelling pleural catheter were high at 93% and 87%, respectively. The predominant issues identified were discomfort at time of insertion (58%), itching (49%), difficulty with sleeping (39%), discomfort with home drainage (36%) and the pleural catheter reminding patients of their disease (63%). Avoiding hospitalisation for the management of dyspnoea was important to 95% of patients. Findings were similar at 3 months. CONCLUSIONS: Indwelling pleural catheters are an effective intervention to directly improve dyspnoea and quality of life but have important disadvantages for some; clinicians and patients should be aware of these when making an informed decision regarding treatment.

Association between frailty and short- and long-term outcomes among critically ill patients: a multicentre prospective cohort study.

BACKGROUND: Frailty is a multidimensional syndrome characterized by loss of physiologic and cognitive reserves that confers vulnerability to adverse outcomes. We determined the prevalence, correlates and outcomes associated with frailty among adults admitted to intensive care. METHODS: We prospectively enrolled 421 critically ill adults aged 50 or more at 6 hospitals across the province of Alberta. The primary exposure was frailty, defined by a score greater than 4 on the Clinical Frailty Scale. The primary outcome measure was in-hospital mortality. Secondary outcome measures included adverse events, 1-year mortality and quality of life. RESULTS: The prevalence of frailty was 32.8% (95% confidence interval [CI] 28.3%-37.5%). Frail patients were older, were more likely to be female, and had more comorbidities and greater functional dependence than those who were not frail. In-hospital mortality was higher among frail patients than among non-frail patients (32% v. 16%; adjusted odds ratio [OR] 1.81, 95% CI 1.09-3.01) and remained higher at 1 year (48% v. 25%; adjusted hazard ratio 1.82, 95% CI 1.28-2.60). Major adverse events were more common among frail patients (39% v. 29%; OR 1.54, 95% CI 1.01-2.37). Compared with nonfrail survivors, frail survivors were more likely to become functionally dependent (71% v. 52%; OR 2.25, 95% CI 1.03-4.89), had significantly lower quality of life and were more often readmitted to hospital (56% v. 39%; OR 1.98, 95% CI 1.22-3.23) in the 12 months following enrolment. INTERPRETATION: Frailty was common among critically ill adults aged 50 and older and identified a population at increased risk of adverse events, morbidity and mortality. Diagnosis of frailty could improve prognostication and identify a vulnerable population that might benefit from follow-up and intervention.

Risk factors and outcomes associated with acute kidney injury following ruptured abdominal aortic aneurysm.

BACKGROUND: Current data describing the epidemiology of acute kidney injury (AKI) following repair of ruptured abdominal aortic aneurysm (rAAA) are limited and long-term outcomes are largely unknown. Our objectives were to describe the incidence rate, risk factors, clinical course and long-term outcomes of AKI following rAAA repair. METHODS: Retrospective population-based cohort study of all referrals undergoing emergency repair of rAAA in Northern Alberta from January 1, 2002 to December 31 2009. Demographic, clinical, physiologic and laboratory data were extracted. AKI was defined and classified according to the AKIN criteria. RESULTS: In total, 140 patients survived to receive emergent rAAA repair. Post-operative AKI occurred in 75.7% of patients (n = 106), 78.3% (n = 83) of which occurred during the initial 24 hours of ICU admission. AKIN stage 1, 2, and 3 occurred in 47 (33.6%), 36 (25.7%) and 23 (16.4%), respectively, with 19 patients receiving renal replacement therapy (RRT). Several clinical and biochemical patient factors were associated with incident AKI, including baseline estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² (odds ratio [OR] 2.94; 95% CI, 1.15-7.51, p = 0.03), need for mechanical ventilation (OR 22.7; 95% CI, 7.0-72.1, p < 0.0001) and vasoactive therapy (OR 9.9; 95% CI, 3.0-32.2, p < 0.0001) and higher mean APACHE II scores (25.7 [8.2] vs. 16.3 [4.9], p < 0.0001). AKI was associated with a higher ICU (28.3% vs. 0%; p = 0.0008) and in-hospital case-fatality rate (35.9% vs. 0%, p = 0.0001). Of 102 survivors to discharge, 65.7% (n = 67) recovered to baseline kidney function. In multivariable analysis, greater severity of AKI (OR 5.01; 95% CI, 2.34-10.7, p < 0.001) and lower baseline eGFR (OR 0.96; 95% CI, 0.93-0.99, p = 0.03) were associated with non-recovery. AKI remained independently associated with 1-year mortality after adjusting for age, sex, comorbidity, and illness severity (OR 5.21; 95% CI, 1.04-26.2, p = 0.045; AUC 0.83; H-L GoF, p = 0.26). Among survivors at 1-year, only 63.4% (n = 55) had complete kidney recovery. CONCLUSIONS: Following rAAA repair, AKI is a common complication independently associated with long-term post-operative mortality. A significant proportion of AKI sufferers in this setting fail to recover to baseline kidney function.

Effect of chemotherapy, immunotherapy, and targeted therapies on removal of indwelling pleural catheters in non-small cell lung cancer patients with malignant pleural effusions.

BACKGROUND: Indwelling pleural catheters (IPCs) are a mainstay therapy for malignant pleural effusions (MPEs). Many patients treated with IPCs achieve pleurodesis. We aimed to identify the effect of systemic therapies for non-small cell lung cancer (NSCLC) on IPC removal in patients with associated MPEs. METHODS: We completed a retrospective cohort study of adult IPC recipients with metastatic NSCLC at the pleural effusion clinic at the Royal Alexandra Hospital from 2009 to 2020. We used logistic regression to assess the rates of IPC removal and Cox regression to assess the time to IPC removal. RESULTS: 232 patients met inclusion criteria with 248 IPCs reviewed. The overall pleurodesis rate was 42.7% with a median time to pleurodesis of 68 (IQR 38-140) days. In univariate analysis, chemotherapy (OR 1.86, CI 0.99-3.49) and epidermal growth factor receptor (EGFR) targeted therapy (OR 3.81, CI 1.86-7.79) were associated with higher rates of pleurodesis. In multivariate analysis, increased rates of pleurodesis were associated with an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of ≤2 (OR 4.82, CI 2.24-10.37) and EGFR targeted therapy (OR 3.87, CI 1.80-8.32). Earlier IPC removal was associated with EGFR targeted therapy in both univariate (HR 1.84, CI 1.20-2.83) and multivariate analysis (HR 1.86, CI 1.19-2.92). CONCLUSIONS: Treatment with EGFR targeted therapy is associated with increased rates and earlier removal of IPC in patients with NSCLC in our cohort. Further large cohort studies are required to determine if this relationship persists.

Combination Tissue Plasminogen Activator and DNase for Loculated Malignant Pleural Effusions: A Single-center Retrospective Review.

BACKGROUND: Indwelling pleural catheters (IPCs) are frequently used for the management of malignant pleural effusions (MPEs), but drainage can be impaired by pleural loculations. We aimed to evaluate the safety and effectiveness of intrapleural tissue plasminogen activator (tPA) versus combination tPA-deoxyribonuclease (DNase) in the treatment of loculated MPE. METHODS: We performed a retrospective review of patients with confirmed or presumed MPEs requiring IPC insertion. We compared the efficacy of intrapleural tPA, tPA-DNase, and procedural intervention on pleural fluid drainage. Secondary endpoints included the need for future pleural procedures (eg, thoracentesis, IPC reinsertion, chest tube insertion, or surgical intervention), IPC removal due to spontaneous pleurodesis, and IPC-related complications. RESULTS: Among 437 patients with MPEs, loculations developed in 81 (19%) patients. Twenty-four (30%) received intrapleural tPA, 46 (57%) received intrapleural tPA-DNase, 4 (5%) underwent a procedural intervention, and 7 (9%) received ongoing medical management. tPA improved pleural drainage in 83% of patients, and tPA-DNase improved pleural drainage in 80% of patients. tPA alone may be associated with increased rates of spontaneous pleurodesis compared with tPA-DNase. There was no difference in complications when comparing tPA, combination tPA-DNase, procedural intervention, and no therapy. CONCLUSION: Both intrapleural tPA and combination tPA-DNase appear to be safe and effective in improving pleural fluid drainage in selected patients with loculated MPE, although further studies are needed.

Elevated cardiac troponin in the early post-operative period and mortality following ruptured abdominal aortic aneurysm: a retrospective population-based cohort study.

INTRODUCTION: Cardiac complications are potentially life-threatening following emergency repair of ruptured abdominal aortic aneurysms (rAAA). Our objectives were to describe the incidence, risk factors, cardiac outcomes and mortality associated with elevated cardiac-specific troponin (cTnI) following repair of rAAA. We hypothesized that early post-operative cTnI elevation (>0.15 mcg/L) in rAAA patients would identify a high-risk subgroup for cardiovascular complications and adverse outcomes. METHODS: This was a retrospective population-based cohort study of all referrals for emergency repair of rAAA in central and northern Alberta, from 1 January 2002 to 31 December 2009. Demographic, clinical, physiologic and laboratory data were extracted, along with cardiac-specific investigations and events in the 72 hours following rAAA repair. RESULTS: In total, 55% of patients (n = 77/141) had elevated cTnI, of which 12% (n = 9) had ST segment elevation, 23% (n = 18) had ST segment depression, 5% (n = 4) had other ECG changes, and 61% (n = 47) had no diagnostic ECG changes. Those with positive cTnI were more likely to have coronary artery disease (45.5% vs. 23.4%, P = 0.01) and higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (24.9 vs. 21.4, n = 0.016). cTnI positive patients were more likely to receive vasoactive support (58.4% vs. 14.1%, P < 0.001), had longer intensive care unit (ICU) lengths of stay (8 (3 to 11) vs. 4 (2 to 9) days, P = 0.02) and higher adjusted in-hospital mortality (40.3% vs. 14.1%; OR 4.23; 95% CI, 1.47 to 12.1; P = 0.007). CONCLUSIONS: Elevated cTnI early after rAAA repair is an independent predictor for post-operative complications and death.

Timing the initiation of renal replacement therapy for acute kidney injury in Canadian intensive care units: a multicentre observational study.

PURPOSE: The optimal timing for starting renal replacement therapy (RRT) in patients with acute kidney injury (AKI) is unknown. Defining current practice is necessary to design interventional trials. We describe the current Canadian practice regarding the timing of RRT initiation for AKI. METHODS: An observational study of patients undergoing RRT for AKI was undertaken at 11 intensive care units (ICUs) across Canada. Data were captured on demographics, clinical and laboratory findings, indications for RRT, and timing of RRT initiation. RESULTS: Among 119 consecutive patients, the most common ICU admission diagnosis was sepsis/septic shock, occurring in 54%. At the time of RRT initiation, the median and interquartile range (IQR) serum creatinine level was 322 (221-432) µmol·L(-1). The mean (SD) values for other parameters were as follows: Sequential Organ Failure Assessment (SOFA) score 13.4 (4.1), pH 7.25 (0.15), potassium 4.6 (1.0) mmol·L(-1). Also, 64% fulfilled the serum creatinine-based criterion for Acute Kidney Injury Network (AKIN) stage 3. Severity of illness, measured using Acute Physiology and Chronic Health Evaluation (APACHE II) and SOFA scores, did not correlate with AKI severity as defined by the serum creatinine-based AKIN criteria. Median (IQR) time from hospital and ICU admission to the start of RRT was 2.0 (1.0-7.0) days and 1.0 (0-2.0) day, respectively. CONCLUSION: Patients admitted to an ICU who were started on RRT generally had advanced AKI, high-grade illness severity, and multiorgan dysfunction. Also, they were started on RRT shortly after hospital presentation. We describe the current state of practice in Canada regarding the initiation of RRT for AKI in critically ill patients, which can inform the designs of future interventional trials.

Endobronchial Ultrasound Transbronchial Needle Aspiration With a 19-Gauge Needle vs 21- and 22-Gauge Needles for Mediastinal Lymphadenopathy.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is commonly used to evaluate mediastinal lymphadenopathy. Studies focusing on malignant lymphadenopathy have compared 21- and 22-gauge (21G and 22G, respectively) needles and have not identified an advantage of one needle size over the other in terms of diagnostic yield. RESEARCH QUESTION: Does the 19-gauge (19G) EBUS needle offer greater diagnostic yield and sensitivity vs the 21G and 22G EBUS needles for a diagnosis of sarcoidosis, lymphoma, or mediastinal lymphadenopathy not yet diagnosed? STUDY DESIGN AND METHODS: This study retrospectively examined records of 730 patients from the Stather Canadian Outcomes Registry for Chest Procedures (SCOPE) database who underwent EBUS-TBNA for a diagnosis of suspected sarcoidosis, lymphoma, or mediastinal lymphadenopathy not yet diagnosed. A propensity score analysis of two groups was performed. One group comprised patients undergoing EBUS-TBNA with a 19G needle, the other with a 21G or 22G needle. Cases for analysis were selected with a 1:2 ratio of 19G vs 21/22G using logistic regression and random matching with all eligible 19G cases included. RESULTS: There were 137 patients (312 targets) in the 19G group and 274 patients (631 targets) in the 21/22G group in the propensity score analysis. The diagnostic yield was 107 of 137 (78.1%) in the 19G group vs 194 of 274 (70.8%) in the 21/22G group (difference, 7.3%; 95% CI, -1.9 to 15.6; P = .116). The sensitivity of EBUS-TBNA for sarcoidosis was 80 of 83 (96.4%) in the 19G group vs 150 of 156 (96.2%) in the 21/22G group (difference, 0.24%; 95% CI, -6.6 to 85.1; P = .93). In patients with a final diagnosis of lymphoma, EBUS was diagnostic in 10 of 13 (76.9%) in the 19G group vs 12 of 12 (100%) in the 21/22G group (difference, 23.1%; 95% CI, -5.4 to 50.3; P = .08). INTERPRETATION: The study did not identify an advantage of the 19G EBUS needle over the 21/22G EBUS needles for diagnostic yield nor sensitivity for sarcoidosis or lymphoma.

Protocol for the Stather Canadian Outcomes Registry for Chest ProcedurEs (SCOPE).

INTRODUCTION: The Stather Canadian Outcomes registry for chest ProcedurEs (SCOPE registry) is a Canadian multicentre registry of chest procedures. METHODS AND ANALYSIS: The SCOPE registry is designed as a multicentre prospective database of specific bronchoscopic or other pulmonary procedures. Each procedure of interest will be associated with a registry module, and data capture designed to evaluate effectiveness of procedures on relevant patient outcomes. Participating physicians will be asked to enter data for all procedures performed in a given module. The anonymised dataset will be housed in a web-based electronic secure database. Specific modules included will be based on participating physician suggestions, capacity and consensus of the steering committee and relevance of hypotheses/research potential. ETHICS AND DISSEMINATION: The central registry is under approval from the Conjoint Health Research Ethics Board at the University of Calgary. We aim for registry data to lead to publication of manuscripts in international medical journals as the primary mode of dissemination. Data may also be used by local investigators for personal and/or institutional quality control purposes as well as to inform health policies. Data requests from non-participating investigators for use under ethics approved research protocols can be considered.

A case-control study of single-pass albumin dialysis for acetaminophen-induced acute liver failure.

BACKGROUND: Extracorporeal support with single-pass albumin dialysis (SPAD) may remove protein-bound toxins in acute liver failure. We evaluated the clinical, physiological and laboratory parameters of SPAD in acetaminophen-induced acute liver failure (AALF). METHODS: Retrospective case-control studies of AALF patients were used. RESULTS: We identified 13 AALF patients (6 SPAD-treated, 7 controls). The average age was 38 years, 92% were female, none had cirrhosis and the Model for End-Stage Liver Disease (MELD) scores were 43. Eleven patients (85%) fulfilled the King's College criteria for a liver transplant. SPAD-treated patients received 21 sessions (total: 147 h, mean 3.5 runs or 24.5 h/patient). There were no complications. No significant changes in clinical, physiological or biochemical parameters occurred during SPAD. Compared with the controls, there were no significant differences in ICU or 1-year survival, liver recovery or referral for a liver transplant. CONCLUSION: SPAD was well-tolerated in AALF; however, it was not associated with differences in clinical outcomes. While SPAD may be an adjuvant supportive therapy in AALF, prospective trials are needed.

Noninvasive ventilation practice patterns for acute respiratory failure in Canadian tertiary care centres: A descriptive analysis.

BACKGROUND: The extent of noninvasive ventilation (NIV) use for patients with acute respiratory failure in Canadian hospitals, indications for use and associated outcomes are unknown. OBJECTIVE: To describe NIV practice variation in the acute setting. METHODS: A prospective observational study involving 11 Canadian tertiary care centres was performed. Data regarding NIV indication, mode and outcomes were collected for all adults (>16 years of age) treated with NIV for acute respiratory failure during a four-week period (between February and August 2011). Logistic regression with site as a random effect was used to examine the association between preselected predictors and mortality or intubation. RESULTS: A total of 330 patients (mean [± SD] 30±12 per centre) were included. The most common indications for NIV initiation were pulmonary edema (104 [31.5%]) and chronic obstructive pulmonary disease (99 [30.0%]). Significant differences in indications for NIV use across sites, specialty of ordering physician and location of NIV initiation were noted. Although intubation rates were not statistically different among sites (range 10.3% to 45.4%), mortality varied significantly (range 6.7% to 54.5%; P=0.006). In multivariate analysis, the most significant independent predictor of avoiding intubation was do-not-resuscitate status (OR 0.11 [95% CI 0.03 to 0.37]). CONCLUSION: Significant variability existed in NIV use and associated outcomes among Canadian tertiary care centres. Assignment of do-not-resuscitate status prevented intubation.

Bedside ultrasound is a practical and reliable measurement tool for assessing quadriceps muscle layer thickness.

BACKGROUND: Critically ill patients commonly experience skeletal muscle wasting that may predict clinical outcome. Ultrasound is a noninvasive method that can measure muscle quadriceps muscle layer thickness (QMLT) and subsequently lean body mass (LBM) at the bedside. However, currently the reliability of these measurements are unknown. The objectives of this study were to evaluate the intra- and interreliability of measuring QMLT using bedside ultrasound. METHODS: Ultrasound measurements of QMLT were conducted at 7 centers on healthy volunteers. Trainers were instructed to perform measurements twice on each patient, and then a second trainee repeated the measurement. Intrarater reliability measured how consistently the same person measured the subject according to intraclass correlation (ICC). Interrater reliability measured how consistently trainer and trainee agreed when measuring the same subject according to the ICC. RESULTS: We collected 42 pairs of within operator measurements with an ICC of .98 and 78 pairs of trainer-to-trainee measurements with an ICC of .95. There were no statistically significant differences between the trainer and trainee results (trainer and trainee mean = -0.028 cm, 95% CI = -0.067 to -0.011, P = .1607). CONCLUSIONS: Excellent intra- and interrater reliability for ultrasound measurements of QMLT in healthy volunteers was observed when performed by a range of providers with no prior ultrasound experience, including dietitians, nurses, physicians, and research assistants. This technique shows promise as a method to evaluate LBM status in ICU or hospital settings and as a method to assess the effects of nutrition and exercise-based interventions on muscle wasting.

Clinical factors associated with initiation of renal replacement therapy in critically ill patients with acute kidney injury-a prospective multicenter observational study.

PURPOSE: Our objective was to describe the current practice for initiation of RRT in this population. There is uncertainty regarding the optimal time to initiate renal replacement therapy (RRT) in critically ill patients with acute kidney injury (AKI). METHODS: Prospective study of patients receiving RRT in 6 intensive care units (ICUs) at 3 hospitals from July 2007 to August 2008. We characterized factors associated with start of RRT and evaluated their relationship with mortality. RESULTS: We included 234 patients. RRT was initiated 1 day (0-4) after ICU admission (median [interquartile range]). Median creatinine was 331 µmol/L (225-446 µmol/L), urea 22.9 mmol/L (13.9-32.9 mmol/L), and RIFLE-Failure in 76.9%. Of traditional indications, Pao(2)/Fio(2) < 200 (54.5%) and oliguria (32.9%) were most common. ICU and hospital mortality were 45.3% and 51.9%, respectively. In adjusted analysis, mortality at RRT initiation was associated with creatinine <332 µmol/L (odds ratio [OR] 2.8; 95% confidence interval [CI] 1.5-5.4), change in urea from admission >8.9 mmol/L (OR 1.8; 95% CI, 1.0-3.4), urine output <82 mL/24 hours (OR 3.0; 95% CI, 1.4-6.5), fluid balance >3.0 L/24 hours (OR 2.3; 95% CI, 1.2-4.5), percentage of fluid overload >5% (OR 2.3; 95% CI, 1.2-4.7), 3 or more failing organs (OR 4.5; 95% CI, 1.2-4.2), Sequential Organ Failure Assessment score >14 (OR 2.3; 95% CI, 1.3-4.3), and start 4 days or more after admission (OR 4.3; 95% CI, 1.9-9.5). Mortality was higher as factors accumulated. CONCLUSION: In ICU patients requiring RRT, there was marked variation in factors that influence start of RRT. RRT initiation with fewer clinical triggers was associated with lower mortality. Timing of RRT may modify survival but requires appraisal in a randomized trial.

Regional citrate versus systemic heparin anticoagulation for continuous renal replacement in critically ill patients.

BACKGROUND: We determined the effect of regional citrate versus systemic heparin anticoagulation for continuous renal replacement therapy in critically ill subjects suffering from acute renal failure who were not at high risk for hemorrhagic complications. METHODS: Between April 1999 and June 2002, 30 critically ill subjects requiring continuous renal replacement therapy and using 79 hemofilters were randomly assigned to receive regional citrate or systemic heparin anticoagulation. RESULTS: The median hemofilter survival time was 124.5 hours (95% CI 95.3 to 157.4) in the citrate group, which was significantly longer than the 38.3 hours (95% CI 24.8 to 61.9) in the heparin group (P < 0.001). Increasing illness severity score, male gender, and decreasing antithrombin-III levels were independent predictors of an increased relative hazard of hemofilter failure. After adjustment for illness severity, antithrombin-III levels increased significantly more over the period of study in the citrate as compared to the heparin group (P= 0.038). Moreover, after adjustment for antithrombin-III levels and illness severity score, the relative risk of hemorrhage with citrate anticoagulation was significantly lower than that with heparin (relative risk of 0.14; 95% CI 0.02 to 0.96, P= 0.05). CONCLUSION: Compared with systemic heparin anticoagulation, regional citrate anticoagulation significantly increases hemofilter survival time, and significantly decreases bleeding risk in critically ill patients suffering from acute renal failure and requiring continuous renal replacement therapy.