Predicting recovery from acute kidney injury in critically ill patients: development and validation of a prediction model.

OBJECTIVE: Intensive care unit (ICU) patients with acute kidney injury (AKI) who recover kidney function within 28 days experience less severe chronic kidney impairment and have increased long term survival. The aims of this study were to develop and validate a risk prediction model to identify these patients. DESIGN: Observational study with development and validation of a risk prediction model. SETTING: Nine academic ICUs in Denmark. PARTICIPANTS: Development cohort of critically ill patients with AKI at ICU admission from the Procalcitonin and Survival Study cohort (n = 568), validation cohort of adult patients with AKI admitted to two university hospitals in Denmark in 2012-13 (n = 766). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Recovery of kidney function was defined as living for 5 consecutive days with no renal replacement therapy and with creatinine plasma levels below 1.5-fold the levels determined before ICU admission. RESULTS: A total of 266 patients (46.8%) recovered prior kidney function in the development cohort, and 453 patients (59.1%) in the validation cohort. The prediction model included elevation in creatinine, urinary output, sex and age. In the validation cohort, 69 patients (9.0%) had a predicted chance of recovery < 25%, and their observed rate of recovery was 21.5%. This observed rate of recovery was 81.7% among the 325 patients who had a predicted chance > 75%. The area under the receiver operations curves for predicting recovery in the validation cohort was 73.1%. CONCLUSION: We constructed and validated a simple model that can predict the chance of recovery from AKI in critically ill patients.

Prediction of non-recovery from ventilator-demanding acute respiratory failure, ARDS and death using lung damage biomarkers: data from a 1200-patient critical care randomized trial.

BACKGROUND: It is unclear whether biomarkers of alveolar damage (surfactant protein D, SPD) or conductive airway damage (club cell secretory protein 16, CC16) measured early after intensive care admittance are associated with one-month clinical respiratory prognosis. If patients who do not recover respiratory function within one month can be identified early, future experimental lung interventions can be aimed toward this high-risk group. We aimed to determine, in a heterogenous critically ill population, whether baseline profound alveolar damage or conductive airway damage has clinical respiratory impact one month after intensive care admittance. METHODS: Biobank study of biomarkers of alveolar and conductive airway damage in intensive care patients was conducted. This was a sub-study of 758 intubated patients from a 1200-patient randomized trial. We split the cohort into a "learning cohort" and "validating cohort" based on geographical criteria: northern sites (learning) and southern sites (validating). RESULTS: Baseline SPD above the 85th percentile in the "learning cohort" predicted low chance of successful weaning from ventilator within 28 days (adjusted hazard ratio 0.6 [95% CI 0.4-0.9], p = 0.005); this was confirmed in the validating cohort. CC16 did not predict the endpoint. The absolute risk of not being successfully weaned within the first month was 48/106 (45.3%) vs. 175/652 (26.8%), p < 0.0001 (high SPD vs. low SPD). The chance of being "alive and without ventilator ≥20 days within the first month" was lower among patients with high SPD (adjusted OR 0.2 [95% CI 0.2-0.4], p < 0.0001), confirmed in the validating cohort, and the risk of ARDS was higher among patients with high SPD (adjusted OR 3.4 [95% CI 1.0-11.4], p = 0.04)-also confirmed in the validating cohort. CONCLUSION: Early profound alveolar damage in intubated patients can be identified by SPD blood measurement at intensive care admission, and high SPD level is a strong independent predictor that the patient suffers from ARDS and will not recover independent respiratory function within one month. This knowledge can be used to improve diagnostic and prognostic models and to identify the patients who most likely will benefit from experimental interventions aiming to preserve alveolar tissue and therefore respiratory function. Trial registration This is a sub-study to the Procalcitonin And Survival Study (PASS), Clinicaltrials.gov ID: NCT00271752, first registered January 1, 2006.

Thromboelastography in patients with severe sepsis: a prospective cohort study.

PURPOSE: To investigate the association between consecutively measured thromboelastographic (TEG) tracings and outcome in patients with severe sepsis. METHODS: Multicentre prospective observational study in a subgroup of the Scandinavian Starch for Severe Sepsis/Septic Shock (6S) Trial (NCT00962156) comparing hydroxyethyl starch (HES) 130/0.42 vs. Ringer's acetate for fluid resuscitation in severe sepsis. TEG (standard and functional fibrinogen) was measured consecutively for 5 days, and clinical data including bleeding and death was retrieved from the trial database. Statistical analyses included Cox regression with time-dependent covariates and joint modelling techniques. RESULTS: Of 267 eligible patients, we analysed 260 patients with TEG data. At 90 days, 68 (26 %) had bled and 139 (53 %) had died. For all TEG variables, hypocoagulability according to the reference range was significantly associated with increased risk of death. In a linear model, hazard ratios for death were 6.03 (95 % confidence interval, 1.64-22.17) for increased clot formation speed, 1.10 (1.04-1.16) for decreased angle, 1.09 (1.05-1.14) for decreased clot strength and 1.12 (1.06-1.18) for decreased fibrinogen contribution to clot strength (functional fibrinogen MA), showing that deterioration towards hypocoagulability in any TEG variable significantly increased the risk of death. Patients treated with HES had lower functional fibrinogen MA than those treated Ringer's acetate, which significantly increased the risk of subsequent bleeding [HR 2.43 (1.16-5.07)] and possibly explained the excess bleeding with HES in the 6S trial. CONCLUSIONS: In our cohort of patients with severe sepsis, progressive hypocoagulability defined by TEG variables was associated with increased risk of death and increased risk of bleeding.

Invasive Candida infections and the harm from antibacterial drugs in critically ill patients: data from a randomized, controlled trial to determine the role of ciprofloxacin, piperacillin-tazobactam, meropenem, and cefuroxime.

OBJECTIVE: Use of antibiotics in critically ill patients may increase the risk of invasive Candida infection. The objective of this study was to determine whether increased exposure to antibiotics is associated with increased prevalence of invasive Candida infection. DESIGN: Substudy using data from a randomized controlled trial, the Procalcitonin And Survival Study 2006-2010. SETTING: Nine multidisciplinary ICUs across Denmark. PATIENTS: A total of 1,200 critically ill patients. INTERVENTION: Patients were randomly allocated to either a "high exposure" antibiotic therapy (intervention arm, n = 604) or a "standard exposure" guided by current guidelines (n = 596). MEASUREMENTS AND MAIN RESULTS: Seventy-four patients met the endpoint, "invasive Candida infection," 40 in the high exposure arm and 34 in standard exposure arm (relative risk = 1.2; 95% CI, 0.7-1.8; p = 0.52). Among medical patients in the high exposure arm, the use of ciprofloxacin and piperacillin/tazobactam was 51% and 75% higher than in the standard exposure arm; no difference in antibiotic exposure was observed between the randomized arms in surgical patients. Among medical intensive care patients, invasive Candida infection was more frequent in the high exposure arm (6.2%; 27/437) than in standard exposure arm (3.3%; 14/424) (hazard ratio = 1.9; 95% CI, 1.0-3.6; p = 0.05). Ciprofloxacin used at study entry independently predicted invasive Candida infection (adjusted hazard ratio = 2.1 [1.1-4.1]); the risk gradually increased with duration of ciprofloxacin therapy: six of 384 in patients not exposed (1.6%), eight of 212 (3.8%) when used for 1-2 days (hazard ratio = 2.5; 95% CI, 0.9-7.3), and 31 of 493 (6.3%) when used for 3 days (hazard ratio = 3.8; 95% CI, 1.6-9.3; p = 0.002). Patients with any ciprofloxacin-containing antibiotic regimen the first 3 days in the trial had a higher risk of invasive Candida infection than did patients on any antibiotic regimen not containing ciprofloxacin (unadjusted hazard ratio = 3.7; 95% CI, 1.6-8.7; p = 0.003; adjusted hazard ratio, 3.4; 95% CI, 1.4-8.0; p = 0.006). CONCLUSIONS: High exposure to antibiotics is associated to increased risk of invasive Candida infection in medical intensive care patients. Patients with ciprofloxacin-containing regimens had higher risk of invasive Candida infection. Other antibiotics, such as meropenem, piperacillin/tazobactam, and cefuroxime, were not associated with such a risk.

The potential of antimicrobials to induce thrombocytopenia in critically ill patients: data from a randomized controlled trial.

BACKGROUND: Antimicrobial-induced thrombocytopenia is frequently described in the literature among critically ill patients. Several antimicrobials have been implicated, although experimental evidence to demonstrate causality is limited. We report, using a randomized trial, the potential of antimicrobials to induce thrombocytopenia. METHODS: Randomized trial allocated patients to antimicrobial treatment according to standard- of-care (SOC group) or drug-escalation in case of procalcitonin increases (high-exposure group). Patients were followed until death or day 28. Thrombocytopenia defined as absolute (platelet count ≤ 100 x 109/L) or relative (≥ 20% decrease in platelet count). Analyses were performed in the two randomized groups and as a merged cohort. RESULTS: Of the 1147 patients with platelet data available, 18% had absolute thrombocytopenia within the first 24 hours after admission to intensive care unit and additional 17% developed this complication during follow-up; 57% developed relative thrombocytopenia during follow-up. Absolute and relative thrombocytopenia day 1-4 was associated with increased mortality (HR: 1.67 [95% CI: 1.30 to 2.14]; 1.71 [95% CI: 1.30 to 2.30], P<0.0001, respectively). Patients in the high-exposure group received more antimicrobials including piperacillin/tazobactam, meropenem and ciprofloxacin compared with the SOC group, whereas cefuroxime was used more frequently in the SOC group (p<0.05). Risk of absolute and relative thrombocytopenia (RR: 0.9 [0.7-1.3], p=0.7439; 1.2 [1.0-1.4], p=0.06; respectively), as well as absolute platelet count (daily difference, high-exposure vs. SOC -1.7 [-3.8-0.5], p=0.14) was comparable between groups. In observational analyses, use of ciprofloxacin and piperacillin/tazobactam predicted risk of relative thrombocytopenia (vs. cefuroxime, RR: 2.08 [1.48-2.92]; 1.44 [1.10-1.89], respectively), however only ciprofloxacin were associated with a reduction in absolute platelet count (p=0.0005). CONCLUSION: High exposure to broad-spectrum antimicrobials does not result in a reduction in thrombocytopenia in critically ill patients. However, single use of ciprofloxacin, and less so piperacillin/tazobactam, may contribute to a lower platelet count. TRIAL REGISTRATION: ClinicalTrials.gov NCT00271752 http://clinicaltrials.gov/ct2/show/NCT00271752.

Kidney failure related to broad-spectrum antibiotics in critically ill patients: secondary end point results from a 1200 patient randomised trial.

OBJECTIVES: To explore whether a strategy of more intensive antibiotic therapy leads to emergence or prolongation of renal failure in intensive care patients. DESIGN: Secondary analysis from a randomised antibiotic strategy trial (the Procalcitonin And Survival Study). The randomised arms were conserved from the primary trial for the main analysis. SETTING: Nine mixed surgical/medical intensive care units across Denmark. PARTICIPANTS: 1200 adult intensive care patients, 18+ years, expected to stay +24 h. EXCLUSION CRITERIA: bilirubin >40 mg/dl, triglycerides >1000 mg/dl, increased risk from blood sampling, pregnant/breast feeding and psychiatric patients. INTERVENTIONS: Patients were randomised to guideline-based therapy ('standard-exposure' arm) or to guideline-based therapy supplemented with antibiotic escalation whenever procalcitonin increased on daily measurements ('high-exposure' arm). MAIN OUTCOME MEASURES: Primary end point: estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2). Secondary end points: (1) delta eGFR after starting/stopping a drug and (2) RIFLE criterion Risk 'R', Injury 'I' and Failure 'F'. Analysis was by intention to treat. RESULTS: 28-day mortality was 31.8% and comparable (Jensen et al, Crit Care Med 2011). A total of 3672/7634 (48.1%) study days during follow-up in the high-exposure versus 3016/6949 (43.4%) in the 'standard-exposure arm were spent with eGFR <60 ml/min/1.73 m(2), p<0.001. In a multiple effects model, 3 piperacillin/tazobactam was identified as causing the lowest rate of renal recovery of all antibiotics used: 1.0 ml/min/1.73 m(2)/24 h while exposed to this drug (95% CI 0.7 to 1.3 ml/min/1.73 m(2)/24 h) vs meropenem: 2.9 ml/min/1.73 m(2)/24 h (2.5 to 3.3 ml/min/1.73 m(2)/24 h)); after discontinuing piperacillin/tazobactam, the renal recovery rate increased: 2.7 ml/min/1.73 m(2)/24 h (2.3 to 3.1 ml/min/1.73 m(2) /24 h)). eGFR <60 ml/min/1.73 m(2) in the two groups at entry and at last day of follow-up was 57% versus 55% and 41% versus 39%, respectively. CONCLUSIONS: Piperacillin/tazobactam was identified as a cause of delayed renal recovery in critically ill patients. This nephrotoxicity was not observed when using other beta-lactam antibiotics. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00271752.

Procalcitonin-guided interventions against infections to increase early appropriate antibiotics and improve survival in the intensive care unit: a randomized trial.

OBJECTIVE: For patients in intensive care units, sepsis is a common and potentially deadly complication and prompt initiation of appropriate antimicrobial therapy improves prognosis. The objective of this trial was to determine whether a strategy of antimicrobial spectrum escalation, guided by daily measurements of the biomarker procalcitonin, could reduce the time to appropriate therapy, thus improving survival. DESIGN: Randomized controlled open-label trial. SETTING: Nine multidisciplinary intensive care units across Denmark. PATIENTS: A total of 1,200 critically ill patients were included after meeting the following eligibility requirements: expected intensive care unit stay of ≥ 24 hrs, nonpregnant, judged to not be harmed by blood sampling, bilirubin <40 mg/dL, and triglycerides <1000 mg/dL (not suspensive). INTERVENTIONS: : Patients were randomized either to the "standard-of-care-only arm," receiving treatment according to the current international guidelines and blinded to procalcitonin levels, or to the "procalcitonin arm," in which current guidelines were supplemented with a drug-escalation algorithm and intensified diagnostics based on daily procalcitonin measurements. MEASUREMENTS AND MAIN RESULTS: The primary end point was death from any cause at day 28; this occurred for 31.5% (190 of 604) patients in the procalcitonin arm and for 32.0% (191 of 596) patients in the standard-of-care-only arm (absolute risk reduction, 0.6%; 95% confidence interval [CI] -4.7% to 5.9%). Length of stay in the intensive care unit was increased by one day (p = .004) in the procalcitonin arm, the rate of mechanical ventilation per day in the intensive care unit increased 4.9% (95% CI, 3.0-6.7%), and the relative risk of days with estimated glomerular filtration rate <60 mL/min/1.73 m was 1.21 (95% CI, 1.15-1.27). CONCLUSIONS: Procalcitonin-guided antimicrobial escalation in the intensive care unit did not improve survival and did lead to organ-related harm and prolonged admission to the intensive care unit. The procalcitonin strategy like the one used in this trial cannot be recommended.

Comparing the effect of hydroxyethyl starch 130/0.4 with balanced crystalloid solution on mortality and kidney failure in patients with severe sepsis (6S--Scandinavian Starch for Severe Sepsis/Septic Shock trial): study protocol, design and rationale for a double-blinded, randomised clinical trial.

BACKGROUND: By tradition colloid solutions have been used to obtain fast circulatory stabilisation in shock, but high molecular weight hydroxyethyl starch (HES) may cause acute kidney failure in patients with severe sepsis. Now lower molecular weight HES 130/0.4 is the preferred colloid in Scandinavian intensive care units (ICUs) and 1st choice fluid for patients with severe sepsis. However, HES 130/0.4 is largely unstudied in patients with severe sepsis. METHODS/DESIGN: The 6S trial will randomize 800 patients with severe sepsis in 30 Scandinavian ICUs to masked fluid resuscitation using either 6% HES 130/0.4 in Ringer's acetate or Ringer's acetate alone. The composite endpoint of 90-day mortality or end-stage kidney failure is the primary outcome measure. The secondary outcome measures are severe bleeding or allergic reactions, organ failure, acute kidney failure, days alive without renal replacement therapy or ventilator support and 28-day and 1/2- and one-year mortality. The sample size will allow the detection of a 10% absolute difference between the two groups in the composite endpoint with a power of 80%. DISCUSSION: The 6S trial will provide important safety and efficacy data on the use of HES 130/0.4 in patients with severe sepsis. The effects on mortality, dialysis-dependency, time on ventilator, bleeding and markers of resuscitation, metabolism, kidney failure, and coagulation will be assessed. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00962156.

The Procalcitonin And Survival Study (PASS) - a randomised multi-center investigator-initiated trial to investigate whether daily measurements biomarker Procalcitonin and pro-active diagnostic and therapeutic responses to abnormal Procalcitonin levels, can improve survival in intensive care unit patients. Calculated sample size (target population): 1000 patients.

BACKGROUND: Sepsis and complications to sepsis are major causes of mortality in critically ill patients. Rapid treatment of sepsis is of crucial importance for survival of patients. The infectious status of the critically ill patient is often difficult to assess because symptoms cannot be expressed and signs may present atypically. The established biological markers of inflammation (leucocytes, C-reactive protein) may often be influenced by other parameters than infection, and may be unacceptably slowly released after progression of an infection. At the same time, lack of a relevant antimicrobial therapy in an early course of infection may be fatal for the patient. Specific and rapid markers of bacterial infection have been sought for use in these patients. METHODS: Multi-centre randomized controlled interventional trial. Powered for superiority and non-inferiority on all measured end points. Complies with, "Good Clinical Practice" (ICH-GCP Guideline (CPMP/ICH/135/95, Directive 2001/20/EC)). Inclusion: 1) Age > or = 18 years of age, 2) Admitted to the participating intensive care units, 3) Signed written informed consent.Exclusion: 1) Known hyper-bilirubinaemia. or hypertriglyceridaemia, 2) Likely that safety is compromised by blood sampling, 3) Pregnant or breast feeding. Computerized Randomisation: Two arms (1:1), n = 500 per arm: Arm 1: standard of care. Arm 2: standard of care and Procalcitonin guided diagnostics and treatment of infection. Primary Trial Objective: To address whether daily Procalcitonin measurements and immediate diagnostic and therapeutic response on day-to-day changes in procalcitonin can reduce the mortality of critically ill patients. DISCUSSION: For the first time ever, a mortality-endpoint, large scale randomized controlled trial with a biomarker-guided strategy compared to the best standard of care, is conducted in an Intensive care setting. Results will, with a high statistical power answer the question: Can the survival of critically ill patients be improved by actively using biomarker procalcitonin in the treatment of infections? 700 critically ill patients are currently included of 1000 planned (June 2008). Two interim analyses have been passed without any safety or futility issues, and the third interim analysis is soon to take place. Trial registration number at clinicaltrials.gov: Id. nr.: NCT00271752).