Critical Care - Most viewed articles

Acute renal failure – definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group

2004-05-24

IntroductionThere is no consensus definition of acute renal failure (ARF) in critically ill patients. More than 30 different definitions have been used in the literature, creating much confusion and making comparisons difficult. Similarly, strong debate exists on the validity and clinical relevance of animal models of ARF; on choices of fluid management and of end-points for trials of new interventions in this field; and on how information technology can be used to assist this process. Accordingly, we sought to review the available evidence, make recommendations and delineate key questions for future studies. Methods: We undertook a systematic review of the literature using Medline and PubMed searches. We determined a list of key questions and convened a 2-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated recommendations and/or directions for future research. Results: We found sufficient consensus on 47 questions to allow the development of recommendations. Importantly, we were able to develop a consensus definition for ARF. In some cases it was also possible to issue useful consensus recommendations for future investigations. We present a summary of the findings. (Full versions of the six workgroups' findings are available on the internet at http://www.ADQI.net) Conclusion: Despite limited data, broad areas of consensus exist for the physiological and clinical principles needed to guide the development of consensus recommendations for defining ARF, selection of animal models, methods of monitoring fluid therapy, choice of physiological and clinical end-points for trials, and the possible role of information technology.

Surviving sepsis: a guide to the guidelines

Jean-Louis Vincent and John C Marshall — 2008-06-30

The revised Surviving Sepsis Campaign (SSC) guidelines for the management of severe sepsis and septic shock have recently been published. These guidelines represent the end product of an intense process and provide a template approach to the early resuscitation and support of patients with sepsis, based on a synthesis of evidence that has been shown to improve the outcome of the septic patient. The SSC guidelines arose from a recognition that care of the septic patient was suboptimal for at least three reasons. First, the entity of sepsis was frequently not diagnosed in a timely fashion, allowing the process to evolve into a life-threatening syndrome of major physiologic organ system dysfunction. Secondly, even when sepsis was recognized, the urgency of treatment was underappreciated – and so haemodynamic resuscitation was tentative, and the administration of effective antibiotic therapy was often delayed. Finally, treatment was often suboptimal, and failed to take advantage of emerging insights into optimal approaches to patient management. The revised guidelines are far from perfect, but they represent the best available synthesis of contemporary knowledge in this area and as such should be promoted.

Acute kidney injury in ICU patients: a comparison between RIFLE and AKIN

2008-08-28

IntroductionIt is currently unknown whether discernible advantages in terms of sensitivity and specificity exist with Acute Kidney Injury Network (AKIN) criteria versus "Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease" (RIFLE) criteria. We evaluated the incidence of acute kidney injury and compared the ability of the maximum RIFLE and maximum AKIN within intensive care unit hospitalization in predicting in-hospital mortality of critically ill patients. Methods: Patients admitted to the Department of Intensive Medicine of our hospital between January 2003 and December 2006 were retrospectively evaluated. Chronic kidney disease patients undergoing dialysis or renal transplant patients were excluded from the analysis. Results: In all, 662 patients (mean age: 58.6+/-19.2 years; 392 male) were evaluated. AKIN allowed the identification of more patients as having acute kidney injury (50.4% versus 43.8%, P=0.018) and classified more patients with Stage 1 (Risk in RIFLE) (21.1% versus 14.7%, P=0.003), however, no differences were observed for Stage 2 (Injury in RIFLE) (10.1% versus 11%, P=0.655) and Stage 3 (Failure in RIFLE) (19.2% versus 18.1%, P=0.672). Mortality was significantly higher for acute kidney injury defined by any of the RIFLE criteria (41.3% versus 11%, P<0.0001; odds ratio 2.78, 95% confidence interval 1.74-4.45, P<0.0001) or AKIN criteria (39.8% versus 8.5%, P<0.0001; odds ratio 3.59, 95% confidence interval 2.14-6.01, P<0.0001). The Area Under the Receiver Operator Characteristic curve for in-hospital mortality was 0.733 for RIFLE (P<0.0001) and 0.750 for AKIN (P<0.0001). There was no statistical differences in mortality by the acute kidney injury definition/classification criteria (P=0.72). Conclusions: Although AKIN criteria could improve sensitivity of acute kidney injury diagnosis, it does not seem to improve the ability of the RIFLE criteria in predicting in-hospital mortality of critically ill patients.

Prognostic value of brain natriuretic peptide in acute pulmonary embolism

Guillaume Coutance, Olivier Le Page, Ted Lo and Martial Hamon — 2008-08-22

IntroductionThe relationship between brain natriuretic peptide (BNP) increase in acute pulmonary embolism (PE) and the increase in mortality and morbidity has frequently been suggested in small studies but its global prognostic performance remains largely undefined. We performed a systematic review and meta-analysis of data to examine the prognostic value of elevated BNP for short-term all-cause mortality and serious adverse events. Methods: The authors reviewed PubMed, BioMed Central, and the Cochrane database and conducted a manual review of article bibliographies. Using a prespecified search strategy, we included a study if it used BNP or N-terminal pro-BNP biomarkers as a diagnostic test in patients with documented PE and if it reported death, the primary endpoint of the meta-analysis, in relation to BNP testing. Studies were excluded if they were performed in patients without certitude of PE or in a subset of patients with cardiogenic shock. Twelve relevant studies involving a total of 868 patients with acute PE at baseline were included in the meta-analysis using a random-effects model. Results: Elevated BNP levels were significantly associated with short-term all-cause mortality (odds ratio [OR] 6.57, 95% confidence interval [CI] 3.11 to 13.91), with death resulting from PE (OR 6.10, 95% CI 2.58 to 14.25), and with serious adverse events (OR 7.47, 95% CI 4.20 to 13.15). The corresponding positive and negative predictive values for death were 14% (95% CI 11% to 18%) and 99% (95% CI 97% to 100%), respectively. Conclusion: This meta-analysis indicates that, while elevated BNP levels can help to identify patients with acute PE at high risk of death and adverse outcome events, the high negative predictive value of normal BNP levels is certainly more useful for clinicians to select patients with a likely uneventful follow-up.

Balloon laryngoscopy reduces head extension and blade leverage in patients with potential cervical spine injury

2000-01-24

Background: Head extension and excessive laryngoscope blade levering motion (LBLM) are undesirable during airway management of trauma patients. We hypothesized that laryngoscopy with a modified blade facilitating glottic exposure by balloon inflation would reduce head extension and LBLM.Patients and methodsSeventeen elective surgery patients were enrolled. Patients lay supine with their heads flat on a rigid board and had a rigid collar around their necks. Laryngoscopy was performed with the modified blade and a standard curved blade. Head extension and LBLM angles were determined upon maximal glottic exposure and compared used paired t-tests. Laryngoscopic view grade and oxygen saturation were also determined. Results: Balloon laryngoscopy resulted in less head extension and LBLM (P <0.001). Laryngoscopic view was approximately identical with both blades, and oxygen saturation was always above 97%. Conclusions: Balloon laryngoscopy reduces head extension and LBLM under simulated cervical spine precautions.

Clinical review: Liberation from mechanical ventilation

Mohamad F El-Khatib and Pierre Bou-Khalil — 2008-08-06

Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated pneumonia, increased length of ICU and hospital stay, and increased cost of care delivery. This review highlights the recent developments in assessing and testing for readiness of liberation from mechanical ventilation, the etiology of weaning failure, the value of weaning protocols, and a simple practical approach for liberation from mechanical ventilation.

Black Hawk Down: The evolution of resuscitation strategies in massive traumatic hemorrhage

Deepika Mohan, Eric B Milbrandt and Louis H Alarcon — 2008-07-23

No abstract available

RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis

2006-05-12

IntroductionThe lack of a standard definition for acute kidney injury has resulted in a large variation in the reported incidence and associated mortality. RIFLE, a newly developed international consensus classification for acute kidney injury, defines three grades of severity – risk (class R), injury (class I) and failure (class F) – but has not yet been evaluated in a clinical series. Methods: We performed a retrospective cohort study, in seven intensive care units in a single tertiary care academic center, on 5,383 patients admitted during a one year period (1 July 2000–30 June 2001). Results: Acute kidney injury occurred in 67% of intensive care unit admissions, with maximum RIFLE class R, class I and class F in 12%, 27% and 28%, respectively. Of the 1,510 patients (28%) that reached a level of risk, 840 (56%) progressed. Patients with maximum RIFLE class R, class I and class F had hospital mortality rates of 8.8%, 11.4% and 26.3%, respectively, compared with 5.5% for patients without acute kidney injury. Additionally, acute kidney injury (hazard ratio, 1.7; 95% confidence interval, 1.28–2.13; P < 0.001) and maximum RIFLE class I (hazard ratio, 1.4; 95% confidence interval, 1.02–1.88; P = 0.037) and class F (hazard ratio, 2.7; 95% confidence interval, 2.03–3.55; P < 0.001) were associated with hospital mortality after adjusting for multiple covariates. Conclusion: In this general intensive care unit population, acute kidney 'risk, injury, failure', as defined by the newly developed RIFLE classification, is associated with increased hospital mortality and resource use. Patients with RIFLE class R are indeed at high risk of progression to class I or class F. Patients with RIFLE class I or class F incur a significantly increased length of stay and an increased risk of inhospital mortality compared with those who do not progress past class R or those who never develop acute kidney injury, even after adjusting for baseline severity of illness, case mix, race, gender and age.

Influence of early antioxidant supplements on clinical evolution and organ function in critically ill cardiac surgery, major trauma, and subarachnoid hemorrhage patients

2008-08-07

IntroductionOxidative stress is involved in the development of secondary tissue damage and organ failure. Micronutrients contributing to the antioxidant (AOX) defense exhibit low plasma levels during critical illness. The aim of this study was to investigate the impact of early AOX micronutrients on clinical outcome in intensive care unit (ICU) patients with conditions characterized by oxidative stress. Methods: We conducted a prospective, randomized, double-blind, placebo-controlled, single-center trial in patients admitted to a university hospital ICU with organ failure after complicated cardiac surgery, major trauma, or subarachnoid hemorrhage. Stratification by diagnosis was performed before randomization. The intervention was intravenous supplements for 5 days (selenium 270 μg, zinc 30 mg, vitamin C 1.1 g, and vitamin B1 100 mg) with a double-loading dose on days 1 and 2 or placebo. Results: Two hundred patients were included (102 AOX and 98 placebo). While age and gender did not differ, brain injury was more severe in the AOX trauma group (P = 0.019). Organ function endpoints did not differ: incidence of acute kidney failure and sequential organ failure assessment score decrease were similar (-3.2 ± 3.2 versus -4.2 ± 2.3 over the course of 5 days). Plasma concentrations of selenium, zinc, and glutathione peroxidase, low on admission, increased significantly to within normal values in the AOX group. C-reactive protein decreased faster in the AOX group (P = 0.039). Infectious complications did not differ. Length of hospital stay did not differ (16.5 versus 20 days), being shorter only in surviving AOX trauma patients (-10 days; P = 0.045). Conclusion: The AOX intervention did not reduce early organ dysfunction but significantly reduced the inflammatory response in cardiac surgery and trauma patients, which may prove beneficial in conditions with an intense inflammation.Trials RegistrationClinical Trials.gov RCT Register: NCT00515736.

High molecular weight hyaluronan: a possible new treatment for sepsis-induced lung injury - a preclinical study in mechanically ventilated rats

2008-08-08

IntroductionMechanical ventilation (MV) with even moderate sized tidal volumes (VT) synergistically increases lung injury in sepsis and has been associated with pro-inflammatory low molecular weight hyaluronan (LMW HA) production. High molecular weight hyaluronan (HMW HA) in contrast has been found to be anti-inflammatory. We hypothesized that HMW HA would inhibit lung injury associated with sepsis and mechanical ventilation. Methods: Sprague-Dawley rats were randomly divided into 4 groups: non-ventilated controls, mechanical ventilation (MV) plus lipopolysaccharide (LPS) infusion as a model of sepsis, and MV plus LPS with HMW HA (1600 kDa) or LMW HA (35 kDa) pretreatment. Rats were mechanically ventilated (MV) with low (7 ml/kg) tidal volumes (VT). LPS (1 or 3 mg/kg) or normal saline was infused 1 hour prior to MV. Animals received HMW HA or LMW HA via intraperitoneal route 18 hours prior to the study or HMW HA (0.025, 0.05 or 0.1%) intravenously one hour after injection of LPS. After 4 hours of ventilation, animals were sacrificed and lung neutrophil and monocyte infiltration, cytokine production, and lung pathology score were measured. Results: LPS induced lung neutrophil infiltration, macrophage inflammatory protein-2 (MIP-2) and tumour necrosis factor-alpha (TNFa) mRNA and protein, and were decreased by both 1600 and 35 kDa HA pretreatment. Only 1600 kDa HA completely blocked both monocyte and neutrophil infiltration and decreased lung injury. When infused intravenously one hour post LPS, 1600 kDa HA inhibited lung neutrophil infiltration, MIP-2 mRNA expression and lung injury in a dose dependent manner. The beneficial effects of HA were partially dependent on positive charge of the compound. Conclusions: HMW HA may prove to be an effective treatment strategy for sepsis induced lung injury with mechanical ventilation.