Anti-Factor-Xa and Activated Partial Thromboplastin Time Concordance and Outcomes in Adults Undergoing Extracorporeal Membrane Oxygenation: A Secondary Analysis of the Pilot Low-Dose Heparin in Critically Ill Patients Undergoing Extracorporeal Membrane Oxygenation Randomized Trial.

OBJECTIVES: To determine the concordance between activated partial thromboplastin time (aPTT) and anti-factor-Xa (anti-Xa) in adults undergoing extracorporeal membrane oxygenation (ECMO) and to identify the factors associated with discordant paired aPTT/anti-Xa. DESIGN: Pre-planned secondary analysis of the Low-Dose Heparin in Critically Ill Patients Undergoing Extracorporeal Membrane Oxygenation pilot randomized unblinded, parallel-group controlled trial. SETTING: Two ICUs in two university hospitals. PATIENTS: Thirty-two critically ill patients who underwent ECMO and who had at least one paired aPTT and anti-Xa assay performed at the same time. INTERVENTIONS: We analyzed the concordance between aPTT and anti-Xa and identified factors associated with discordant paired aPTT/anti-Xa based on their respective therapeutic ranges. We also compared biological parameters between heparin resistance episode and no heparin resistance. MEASUREMENTS AND MAIN RESULTS: Of the 32 patients who were included in this study, 24 (75%) had at least one discordant paired aPTT/anti-Xa. Of the 581 paired aPTT/anti-Xa that were analyzed, 202 were discordant. The aPTT was relatively lower than anti-Xa in 66 cases (32.7%) or relatively higher than anti-Xa in 136 cases (67.3%). Thirty-three heparin resistance episodes were identified in six patients (19%). CONCLUSIONS: In these critically ill patients undergoing ECMO, one third of paired aPTT/anti-Xa measures was discordant. Coagulopathy and heparin resistance might be the reasons for discordance. Our results support the potential importance of routinely monitoring both tests in this setting.

Effects of brain tissue oxygen (PbtO2) guided management on patient outcomes following severe traumatic brain injury: A systematic review and meta-analysis.

Monitoring and optimisation of brain tissue oxygen tension (PbtO2) has been associated with improved neurological outcome and survival in observational studies of severe traumatic brain injury (TBI). We carried out a systematic review of randomized controlled trials to determine if PbtO2-guided management is associated with differential neurological outcomes, survival, and adverse events. Searches were carried out to 10 February 2022 in Medline (OvidSP), 11 February in EMBASE (OvidSP) and 8 February in Cochrane library. Randomized controlled trials comparing PbtO2 and ICP-guided management to ICP-guided management alone were included. The primary outcome was survival with favourable neurological outcome at 6-months post injury. Data were extracted by two independent authors and GRADE certainty of evidence assessed. There was no difference in the proportion of patients with favourable neurological outcomes with PbtO2-guided management (relative risk [RR] 1.42, 95% CI 0.97 to 2.08; p = 0.07; I2 = 0%, very low certainty evidence) but PbtO2-guided management was associated with reduced mortality (RR 0.54, 95% CI 0.31 to 0.93; p = 0.03; I2 = 42%; very low certainty evidence) and ICP (mean difference (MD) - 4.62, 95% CI - 8.27 to - 0.98; p = 0.01; I2 = 63%; very low certainty evidence). There was no significant difference in the risk of adverse respiratory or cardiovascular events. PbtO2-guided management in addition to ICP-based care was not significantly associated with increased favourable neurological outcomes, but was associated with increased survival and reduced ICP, with no difference in respiratory or cardiovascular adverse events. However, based on GRADE criteria, the certainty of evidence provided by this meta-analysis was consistently very low. MESH: Brain Ischemia; Intensive Care; Glasgow Outcome Scale; Randomized Controlled Trial; Craniocerebral Trauma.

Characteristics, management and outcomes of patients with severe traumatic brain injury in Victoria, Australia compared to United Kingdom and Europe: A comparison between two harmonised prospective cohort studies.

OBJECTIVE: The aim of this manuscript is to compare characteristics, management, and outcomes of patients with severe Traumatic Brain Injury (TBI) between Australia, the United Kingdom (UK) and Europe. METHODS: We enrolled patients with severe TBI in Victoria, Australia (OzENTER-TBI), in the UK and Europe (CENTER-TBI) from 2015 to 2017. Main outcome measures were mortality and unfavourable outcome (Glasgow Outcome Scale Extended <5) 6 months after injury. Expected outcomes were compared according to the IMPACT-CT prognostic model, with observed to expected (O/E) ratios and 95% confidence intervals. RESULTS: We included 107 patients from Australia, 171 from UK, and 596 from Europe. Compared to the UK and Europe, patients in Australia were younger (median 32 vs 44 vs 44 years), a larger proportion had secondary brain insults including hypotension (30% vs 17% vs 21%) and a larger proportion received ICP monitoring (75% vs 74% vs 58%). Hospital length of stay was shorter in Australia than in the UK (median: 17 vs 23 vs 16 days), and a higher proportion of patients were discharged to a rehabilitation unit in Australia than in the UK and Europe (64% vs 26% vs 28%). Mortality overall was lower than expected (27% vs 35%, O/E ratio 0.77 [95% CI: 0.64 - 0.87]. O/E ratios were comparable between regions for mortality in Australia 0.86 [95% CI: 0.49-1.23] vs UK 0.82 [0.51-1.15] vs Europe 0.76 [0.60-0.87]). Unfavourable outcome rates overall were in line with historic expectations (O/E ratio 1.32 [0.96-1.68] vs 1.13 [0.84-1.42] vs 0.96 [0.85-1.09]). CONCLUSIONS: There are major differences in case-mix between Australia, UK, and Europe; Australian patients are younger and have a higher rate of secondary brain insults. Despite some differences in management and discharge policies, mortality was less than expected overall, and did not differ between regions. Functional outcomes were similar between regions, but worse than expected, emphasizing the need to improve treatment for patients with severe TBI.

EPO treatment does not alter acute serum profiles of GFAP and S100B after TBI: A brief report on the Australian EPO-TBI clinical trial.

PURPOSE: To determine the diagnostic and prognostic value of glial fibrillary acidic protein (GFAP) and S100B after traumatic brain injury (TBI) in an Erythropoietin (EPO) clinical trial and examine whether EPO therapy reduces biomarker concentrations. MATERIALS AND METHODS: Forty-four patients with moderate-to-severe TBI were enrolled to a sub-study of the EPO-TBI trial. Patients were randomized to either Epoetin alfa 40,000 IU or 1 ml sodium chloride 0.9 as subcutaneous injection within 24 h of TBI. RESULTS: GFAP and S100B were measured in serum by ELISA from D0 (within 24 h of injury, prior to EPO/vehicle administration) to D5. Biomarker concentrations were compared between injury severities, diffuse vs. focal TBI, 6-month outcome scores (GOS-E) and EPO or placebo treatments. At D0 GFAP was significantly higher than S100B (951 pg/mL vs. 476 pg/mL, p = 0.018). ROC analysis of S100B at 1D post-injury distinguished favorable vs. unfavorable outcomes (area under the curve = 0.73; p = 0.01). EPO did not reduce concentration of either biomarker. CONCLUSIONS: Elevated serum concentrations of GFAP and S100B after TBI reflect a robust, acute glial response to injury. Consistent with lack of improved outcome in TBI patients treated with EPO and prior findings on neuronal and axonal markers, glial biomarker concentrations and acute profiles were not affected by EPO.

Arterio-VENouS Intra Subject agreement for blood gases within intensive care: The AVENSIS study.

BACKGROUND: In critically ill patients, who require multiple blood gas assessments, agreement between arterial and venous blood gas values for pH and partial pressure of carbon dioxide, is not clear. Good agreement would mean that venous values could be used to assess ventilation and metabolic status of patients in intensive care unit. METHODS: All adult patients admitted to Alfred intensive care unit, Melbourne, from February 2013 to January 2014, who were likely to have arterial and central venous lines for three days, were enrolled. Patients on extra-corporeal life support and pregnant women were excluded. After enrolment, near simultaneous arterial and central venous sampling and analysis were performed at least once per nursing shift till the lines were removed or the patient died. Bland-Altman analysis for repeated measures was performed to assess the agreement between arterio-venous pH and partial pressure of carbon dioxide. RESULTS: A total of 394 paired blood gas analyses were performed from 59 participants. The median (IQR) number of samples per patient was 6 (5-9) with the median (IQR) sampling interval 9.4 (5.2-18.5) h. The mean bias for pH was + 0.036 with 95% limits of agreement ranging from - 0.005 to + 0.078. For partial pressure of carbon dioxide, the values were -2.58 and -10.43 to + 5.27 mmHg, respectively. CONCLUSIONS: The arterio-venous agreement for pH in intensive care unit patients appears to be acceptable. However, the agreement for partial pressure of carbon dioxide was poor.

Maximal Recruitment Open Lung Ventilation in Acute Respiratory Distress Syndrome (PHARLAP). A Phase II, Multicenter Randomized Controlled Clinical Trial.

Rationale: Open lung ventilation strategies have been recommended in patients with acute respiratory distress syndrome (ARDS).Objectives: To determine whether a maximal lung recruitment strategy reduces ventilator-free days in patients with ARDS.Methods: A phase II, multicenter randomized controlled trial in adults with moderate to severe ARDS. Patients received maximal lung recruitment, titrated positive end expiratory pressure and further Vt limitation, or control "protective" ventilation.Measurements and Main Results: The primary outcome was ventilator-free days at Day 28. Secondary outcomes included mortality, barotrauma, new use of hypoxemic adjuvant therapies, and ICU and hospital stay. Enrollment halted October 2, 2017, after publication of ART (Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial), when 115 of a planned 340 patients had been randomized (57% male; mean age, 53.6 yr). At 28 days after randomization, there was no difference between the maximal lung recruitment and control ventilation strategies in ventilator-free days (median, 16 d [interquartile range (IQR), 0-21 d], n = 57, vs. 14.5 d [IQR, 0-21.5 d], n = 56; P = 0.95), mortality (24.6% [n = 14/56] vs. 26.8% [n = 15/56]; P = 0.79), or the rate of barotrauma (5.2% [n = 3/57] vs. 10.7% [n = 6/56]; P = 0.32). However, the intervention group showed reduced use of new hypoxemic adjuvant therapies (i.e., inhaled nitric oxide, extracorporeal membrane oxygenation, prone; median change from baseline 0 [IQR, 0-1] vs. 1 [IQR, 0-1]; P = 0.004) and increased rates of new cardiac arrhythmia (n = 17 [29%] vs. n = 7 [13%]; P = 0.03).Conclusions: Compared with control ventilation, maximal lung recruitment did not reduce the duration of ventilation-free days or mortality and was associated with increased cardiovascular adverse events but lower use of hypoxemic adjuvant therapies.Clinical trial registered with www.clinicaltrials.gov (NCT01667146).

Low-Dose Versus Therapeutic Anticoagulation in Patients on Extracorporeal Membrane Oxygenation: A Pilot Randomized Trial.

OBJECTIVES: To determine whether randomization of patients undergoing extracorporeal membrane oxygenation to either therapeutic or a low-dose anticoagulation protocol results in a difference in activated partial thromboplastin time and anti-Xa. DESIGN: Randomized, controlled, unblinded study. SETTING: Two ICUs of two university hospitals. PATIENTS: Patients admitted to the ICU, who required extracorporeal membrane oxygenation (venovenous or venoarterial) and who did not have a preexisting indication for therapeutic anticoagulation. INTERVENTIONS: Therapeutic anticoagulation with heparin (target activated partial thromboplastin time between 50 and 70 s) or lower dose heparin (up to 12,000 U/24 hr aiming for activated partial thromboplastin time < 45 s). MEASUREMENTS AND MAIN RESULTS: Thirty-two patients were randomized into two study groups that were not significantly different in demographics and extracorporeal membrane oxygenation characteristics. There was a significant difference in the daily geometric mean heparin dose (11,742 U [95% CI, 8,601-16,031 U] vs 20,710 U [95% CI, 15,343-27,954 U]; p = 0.004), daily geometric mean activated partial thromboplastin time (48.1 s [95% CI, 43.5-53.2 s] vs 55.5 s [95% CI, 50.4-61.2 s]; p = 0.04), and daily geometric mean anti-Xa (0.11 international units/mL [95% CI, 0.07-0.18] vs 0.27 [95% CI, 0.17-0.42]; p = 0.01). We found similar results when considering only venovenous extracorporeal membrane oxygenation episodes; however, no difference in daily geometric mean activated partial thromboplastin time between groups when considering only venoarterial extracorporeal membrane oxygenation episodes. CONCLUSIONS: Allocating patients on extracorporeal membrane oxygenation to two different anticoagulation protocols led to a significant difference in mean daily activated partial thromboplastin time and anti-Xa levels between groups. When considering subgroups analyses, these results were consistent in patients on venovenous extracorporeal membrane oxygenation. Our results support the feasibility of a larger trial in patients undergoing venovenous extracorporeal membrane oxygenation to compare different anticoagulation protocols; however, this study does not provide evidence on the optimal anticoagulation protocol for patients undergoing extracorporeal membrane oxygenation.

Cost-Effectiveness of Erythropoietin in Traumatic Brain Injury: A Multinational Trial-Based Economic Analysis.

The EPO-TBI multi-national randomized controlled trial found that erythropoietin (EPO), when compared to placebo, did not affect 6-month neurological outcome, but reduced illness severity-adjusted mortality in patients with traumatic brain injury (TBI), making the cost-effectiveness of EPO in TBI uncertain. The current study uses patient-level data from the EPO-TBI trial to evaluate the cost-effectiveness of EPO in patients with moderate or severe TBI from the healthcare payers' perspective. We addressed the issue of transferability in multi-national trials by estimating costs and effects for specific geographical regions of the study (Australia/New Zealand, Europe, and Saudi Arabia). Unadjusted mean quality-adjusted life-years (QALYs; 95% confidence interval [CI]) at 6 months were 0.027 (0.020-0.034; p < 0.001) higher in the EPO group, with an adjusted QALY increment of 0.014 (0.000-0.028; p = 0.04). Mean unadjusted costs (95% CI) were $US5668 (-9191 to -2144; p = 0.002) lower in the treatment group; controlling for baseline IMPACT-TBI score and regional heterogeneity reduced this difference to $2377 (-12,446 to 7693; p = 0.64). For a willingness-to-pay threshold of $US50,000 per QALY, 71.8% of replications were considered cost-effective. Therefore, we did not find evidence that EPO was significantly cost-effective in the treatment of moderate or severe TBI at 6-month follow-up.

Effect of Early Sustained Prophylactic Hypothermia on Neurologic Outcomes Among Patients With Severe Traumatic Brain Injury: The POLAR Randomized Clinical Trial.

Importance: After severe traumatic brain injury, induction of prophylactic hypothermia has been suggested to be neuroprotective and improve long-term neurologic outcomes. Objective: To determine the effectiveness of early prophylactic hypothermia compared with normothermic management of patients after severe traumatic brain injury. Design, Setting, and Participants: The Prophylactic Hypothermia Trial to Lessen Traumatic Brain Injury-Randomized Clinical Trial (POLAR-RCT) was a multicenter randomized trial in 6 countries that recruited 511 patients both out-of-hospital and in emergency departments after severe traumatic brain injury. The first patient was enrolled on December 5, 2010, and the last on November 10, 2017. The final date of follow-up was May 15, 2018. Interventions: There were 266 patients randomized to the prophylactic hypothermia group and 245 to normothermic management. Prophylactic hypothermia targeted the early induction of hypothermia (33°C-35°C) for at least 72 hours and up to 7 days if intracranial pressures were elevated, followed by gradual rewarming. Normothermia targeted 37°C, using surface-cooling wraps when required. Temperature was managed in both groups for 7 days. All other care was at the discretion of the treating physician. Main Outcomes and Measures: The primary outcome was favorable neurologic outcomes or independent living (Glasgow Outcome Scale-Extended score, 5-8 [scale range, 1-8]) obtained by blinded assessors 6 months after injury. Results: Among 511 patients who were randomized, 500 provided ongoing consent (mean age, 34.5 years [SD, 13.4]; 402 men [80.2%]) and 466 completed the primary outcome evaluation. Hypothermia was initiated rapidly after injury (median, 1.8 hours [IQR, 1.0-2.7 hours]) and rewarming occurred slowly (median, 22.5 hours [IQR, 16-27 hours]). Favorable outcomes (Glasgow Outcome Scale-Extended score, 5-8) at 6 months occurred in 117 patients (48.8%) in the hypothermia group and 111 (49.1%) in the normothermia group (risk difference, 0.4% [95% CI, -9.4% to 8.7%]; relative risk with hypothermia, 0.99 [95% CI, 0.82-1.19]; P = .94). In the hypothermia and normothermia groups, the rates of pneumonia were 55.0% vs 51.3%, respectively, and rates of increased intracranial bleeding were 18.1% vs 15.4%, respectively. Conclusions and Relevance: Among patients with severe traumatic brain injury, early prophylactic hypothermia compared with normothermia did not improve neurologic outcomes at 6 months. These findings do not support the use of early prophylactic hypothermia for patients with severe traumatic brain injury. Trial Registration: clinicaltrials.gov Identifier: NCT00987688; Anzctr.org.au Identifier: ACTRN12609000764235.

Permissive Hypercapnia, Alveolar Recruitment and Low Airway Pressure (PHARLAP): a protocol for a phase 2 trial in patients with acute respiratory distress syndrome.

BACKGROUND: Mechanical ventilation is a life-saving intervention that maintains gas exchange in patients with acute respiratory distress syndrome (ARDS); however, it is associated with high mortality and it may augment, or even initiate, lung injury. An open lung ventilation strategy that combines alveolar recruitment manoeuvres with individually titrated positive end-expiratory pressure (PEEP) and targeting lower tidal volumes, or driving pressures by a permissive approach to hypercapnia, may reduce the lung injury associated with mechanical ventilation. This protocol reports the rationale, study design and analysis plan of the Permissive Hypercapnia, Alveolar Recruitment and Low Airway Pressure (PHARLAP) trial. METHODS AND DESIGN: PHARLAP is a phase 2, international, multicentre, prospective, randomised, controlled, parallel-group clinical trial, which aims to determine if staircase alveolar recruitment and individually titrated PEEP, when combined with permissive hypercapnia and low airway pressures, increases ventilator-free days to Day 28 when compared with conventional mechanical ventilation (Acute Respiratory Distress Syndrome Clinical Network [ARDSNet] strategy) in patients with moderate to severe ARDS. This study will enrol 340 patients. The intervention group will receive daily staircase alveolar recruitment manoeuvres with incremental PEEP to a maximum of 40 cmH2O and peak pressures to a maximum of 55 cmH2O. PEEP will be titrated individually against peripheral oxygen saturation, targeting lower tidal volumes by a permissive approach to hypercapnia. In the control group, patients will receive mechanical ventilation following the ARDSNet-ARMA trial protocol, including PEEP titrated with a PEEP/fraction of inspired oxygen (FiO2) chart. Both groups will receive airway pressures ≤30 cmH2O and tidal volumes of ≤ 6 mL/kg predicted bodyweight or less. The primary outcome is ventilator-free days to Day 28. Secondary outcomes include oxygenation and lung compliance, intensive care unit (ICU) and hospital length of stay, use of rescue therapies for refractory hypoxaemia, rate of barotrauma, mortality (ICU, hospital and at 28, 90 and 180 days), quality of life and a health economic analysis at 6 months. DISCUSSION: The PHARLAP trial will determine whether the intervention strategy is effective in increasing ventilator-free days in patients with ARDS. If the PHARLAP strategy is proven to improve ventilator-free days, it will provide a strong impetus to conduct an international phase 3 trial to determine the effects of this strategy on mortality. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01667146.

Statistical analysis plan for the POLAR-RCT: The Prophylactic hypOthermia trial to Lessen trAumatic bRain injury-Randomised Controlled Trial.

BACKGROUND: The Prophylactic hypOthermia to Lessen trAumatic bRain injury-Randomised Controlled Trial (POLAR-RCT) will evaluate whether early and sustained prophylactic hypothermia delivered to patients with severe traumatic brain injury improves patient-centred outcomes. METHODS: The POLAR-RCT is a multicentre, randomised, parallel group, phase III trial of early, prophylactic cooling in critically ill patients with severe traumatic brain injury, conducted in Australia, New Zealand, France, Switzerland, Saudi Arabia and Qatar. A total of 511 patients aged 18-60 years have been enrolled with severe acute traumatic brain injury. The trial intervention of early and sustained prophylactic hypothermia to 33 °C for 72 h will be compared to standard normothermia maintained at a core temperature of 37 °C. The primary outcome is the proportion of favourable neurological outcomes, comprising good recovery or moderate disability, observed at six months following randomisation utilising a midpoint dichotomisation of the Extended Glasgow Outcome Scale (GOSE). Secondary outcomes, also assessed at six months following randomisation, include the probability of an equal or greater GOSE level, mortality, the proportions of patients with haemorrhage or infection, as well as assessment of quality of life and health economic outcomes. The planned sample size will allow 80% power to detect a 30% relative risk increase from 50% to 65% (equivalent to a 15% absolute risk increase) in favourable neurological outcome at a two-sided alpha of 0.05. DISCUSSION: Consistent with international guidelines, a detailed and prospective analysis plan has been developed for the POLAR-RCT. This plan specifies the statistical models for evaluation of primary and secondary outcomes, as well as defining covariates for adjusted analyses and methods for exploratory analyses. Application of this statistical analysis plan to the forthcoming POLAR-RCT trial will facilitate unbiased analyses of these important clinical data. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00987688 (first posted 1 October 2009); Australian New Zealand Clinical Trials Registry, ACTRN12609000764235 . Registered on 3 September 2009.

A Phase 1 Study of a Novel Bidirectional Perfusion Cannula in Patients Undergoing Femoral Cannulation for Cardiac Surgery.

OBJECTIVE: Leg ischemia is a serious complication of femoral artery cannulation. The primary aim of this study was to assess the safety and efficacy of a novel bidirectional femoral arterial cannula (Sorin Group USA, a wholly owned subsidiary of LivaNova PLC, Arvada, CO USA) that provides both antegrade and retrograde flow, in patients undergoing peripheral cannulation for cardiopulmonary bypass during cardiac surgery. METHODS: Patients undergoing routine cardiac surgery requiring femoral artery cannulation for cardiopulmonary bypass were identified preoperatively. Informed written consent was obtained in all cases. Bidirectional cannula insertion used either a surgical cut-down and wire through needle approach or a percutaneous technique. Flow in the superficial femoral artery was assessed using Doppler ultrasound after commencement of cardiopulmonary bypass. Lower limb perfusion was assessed using reflectance near-infrared spectroscopy to measure regional oxygen saturations in the cannulated limb during cardiopulmonary bypass. RESULTS: Fifteen patients (median age = 61.3 years, range = 26-79 years, 10 males, 5 females) underwent femoral arterial cannulation using the novel bidirectional femoral cannula between August 2016 and May 2017. Fourteen cannulae were inserted directly into the femoral artery via a surgical cut-down and wire through needle technique. One bidirectional cannula was inserted using a percutaneous insertion technique. Indications included minimally invasive mitral and aortic valve surgery, thoracic aortic aneurysm repair, and redo cardiac surgery. The median duration of cardiopulmonary bypass was 129 minutes (range = 53-228 minutes). The cannula was inserted and positioned without difficulty in 14 of 15 patients. Incorrect sizing and arterial spasm prevented correct cannula positioning in one patient. Antegrade flow in the superficial femoral artery was observed on Doppler ultrasound in 12 of 12 patients in which this was performed. Continuous stable distal perfusion was demonstrated in the cannulated limb in 14 of 15 patients. No procedural complications occurred in the immediate or convalescent postoperative period. CONCLUSIONS: This study demonstrates that in patients undergoing femoral arterial cannulation for cardiopulmonary bypass during cardiac surgery, the use of a novel bidirectional cannula is safe and easy to insert and provides stable distal perfusion of the cannulated limb. Use of the device should largely obviate the need to insert a separate downstream perfusion cannula or use other techniques to protect against lower limb ischemia. Further research on a larger scale and in different patient populations is now warranted.

Erythropoietin Does Not Alter Serum Profiles of Neuronal and Axonal Biomarkers After Traumatic Brain Injury: Findings From the Australian EPO-TBI Clinical Trial.

OBJECTIVE: To determine profiles of serum ubiquitin carboxy-terminal hydrolase L1 and phosphorylated neurofilament heavy-chain, examine whether erythropoietin administration reduce their concentrations, and whether biomarkers discriminate between erythropoietin and placebo treatment groups. DESIGN: Single-center, prospective observational study. SETTING: A sub-study of the erythropoietin-traumatic brain injury clinical trial, conducted at the Alfred Hospital, Melbourne, Australia. PATIENTS: Forty-four patients with moderate-to-severe traumatic brain injury. INTERVENTIONS: Epoetin alfa 40,000 IU or 1 mL sodium chloride 0.9 as subcutaneous injection within 24 hours of traumatic brain injury. MEASUREMENTS AND MAIN RESULTS: Ubiquitin carboxy-terminal hydrolase L1, phosphorylated neurofilament heavy-chain, and erythropoietin concentrations were measured in serum by enzyme-linked immunosorbent assay from D0 (within 24 hr of injury, prior to erythropoietin/vehicle administration) to D5. Biomarker concentrations were compared between injury severities, diffuse versus focal traumatic brain injury and erythropoietin or placebo treatment groups. Ubiquitin carboxy-terminal hydrolase L1 peaked at 146.0 ng/mL on D0, significantly decreased to 84.30 ng/mL on D1, and declined thereafter. Phosphorylated neurofilament heavy-chain levels were lowest at D0 and peaked on D5 at 157.9 ng/mL. D0 ubiquitin carboxy-terminal hydrolase L1 concentrations were higher in diffuse traumatic brain injury. Peak phosphorylated neurofilament heavy-chain levels on D3 and D4 correlated with Glasgow Outcome Score-Extended, predicting poor outcome. Erythropoietin did not reduce concentrations of ubiquitin carboxy-terminal hydrolase L1 or phosphorylated neurofilament heavy-chain. CONCLUSIONS: Serum ubiquitin carboxy-terminal hydrolase L1 and phosphorylated neurofilament heavy-chain increase after traumatic brain injury reflecting early neuronal and progressive axonal injury. Consistent with lack of improved outcome in traumatic brain injury patients treated with erythropoietin, biomarker concentrations and profiles were not affected by erythropoietin. Pharmacokinetics of erythropoietin suggest that the dose given was possibly too low to exert neuroprotection.

Erythropoietin in traumatic brain injury (EPO-TBI): a double-blind randomised controlled trial.

BACKGROUND: Erythropoietin might have neurocytoprotective effects. In this trial, we studied its effect on neurological recovery, mortality, and venous thrombotic events in patients with traumatic brain injury. METHODS: Erythropoietin in Traumatic Brain Injury (EPO-TBI) was a double-blind, placebo-controlled trial undertaken in 29 centres (all university-affiliated teaching hospitals) in seven countries (Australia, New Zealand, France, Germany, Finland, Ireland, and Saudi Arabia). Within 24 h of brain injury, 606 patients were randomly assigned by a concealed web-based computer-generated randomisation schedule to erythropoietin (40,000 units subcutaneously) or placebo (0·9% sodium chloride subcutaneously) once per week for a maximum of three doses. Randomisation was stratified by severity of traumatic brain injury (moderate vs severe) and participating site. With the exception of designated site pharmacists, the site dosing nurses at all sites, and the pharmacists at the central pharmacy in France, all study personnel, patients, and patients' relatives were masked to treatment assignment. The primary outcome, assessed at 6 months by modified intention-to-treat analysis, was improvement in the patients' neurological status, summarised as a reduction in the proportion of patients with an Extended Glasgow Outcome Scale (GOS-E) of 1-4 (death, vegetative state, and severe disability). Two equally spaced preplanned interim analyses were done (after 202 and 404 participants were enrolled). This study is registered with ClinicalTrials.gov, number NCT00987454. FINDINGS: Between May 3, 2010, and Nov 1, 2014, 606 patients were enrolled and randomly assigned to erythropoietin (n=308) or placebo (n=298). Ten of these patients (six in the erythropoietin group and four in the placebo group) were lost to follow up at 6 months; therefore, data for the primary outcome analysis was available for 596 patients (302 in the erythropoietin group and 294 in the placebo group). Compared with placebo, erythropoietin did not reduce the proportion of patients with a GOS-E level of 1-4 (134 [44%] of 302 patients in the erythropoietin group vs 132 [45%] of 294 in the placebo group; relative risk [RR] 0·99 [95% CI 0·83-1·18], p=0·90). In terms of safety, erythropoietin did not significantly affect 6-month mortality versus placebo (32 [11%] of 305 patients had died at 6 months in the erythropoietin group vs 46 [16%] of 297 [16%] in the placebo group; RR 0·68 [95% CI 0·44-1·03], p=0·07) or increase the occurrence of deep venous thrombosis of the lower limbs (48 [16%] of 305 vs 54 [18%] of 298; RR 0·87 [95% CI 0·61-1·24], p=0·44). INTERPRETATION: Following moderate or severe traumatic brain injury, erythropoietin did not reduce the number of patients with severe neurological dysfunction (GOS-E level 1-4) or increase the incidence of deep venous thrombosis of the lower limbs. The effect of erythropoietin on mortality remains uncertain. FUNDING: The National Health and Medical Research Council and the Transport Accident Commission.

Heparin-induced thrombocytopenia in the critically ill: interpreting the 4Ts test in a randomized trial.

BACKGROUND: Thrombocytopenia occurs in 20% to 45% of critically ill medical-surgical patients. The 4Ts heparin-induced thrombocytopenia (HIT) score (with 4 domains: Thrombocytopenia, Timing of thrombocytopenia, Thrombosis and oTher reason[s] for thrombocytopenia) might reliably identify patients at low risk for HIT. Interobserver agreement on 4Ts scoring is uncertain in this setting. OBJECTIVE: To evaluate whether a published clinical prediction rule (the "4Ts score") reliably rules out HIT in "low-risk" intensive care unit (ICU) patients as assessed by research coordinators (who prospectively scored) and 2 adjudicators (who scored retrospectively) during an international heparin thromboprophylaxis trial (PROTECT, NCT00182143). METHODS: Of 3746 medical-surgical ICU patients in PROTECT, 794 met the enrollment criteria for this HIT substudy. Enrollment was predicated on one of the following occurring in ICU: platelets less than 50×10(9)/L, platelets decreased to 50% of ICU admission value (if admission value<100×10(9)/L), any venous thrombosis, or if HIT was otherwise clinically suspected. Independently, 4Ts scores were completed in real time by research coordinators blinded to study drug and laboratory HIT results, and retrospectively by 2 adjudicators blinded to study drug, laboratory HIT results, and research coordinators' scores; the adjudicators arrived at consensus in all cases. Of the 763 patients, 474 had a central or local laboratory HIT test performed and had 4Ts scoring by adjudicators; 432 were scored by trained research coordinators. Heparin-induced thrombocytopenia was defined by a centrally performed positive serotonin release assay (SRA). RESULTS: Of the 474 patients with central adjudication, 407 (85.9%) had a 4Ts score of 3 or lower, conferring a low pretest probability (PTP) of HIT; of these, 6 (1.5% [95% confidence interval, 0.7%-3.2%) had a positive SRA. Fifty-nine (12.4%) had a moderate PTP (4Ts score of 4-5); of these, 4 (6.8%) had a positive SRA. Eight patients had a high PTP (4Ts score of ≥6); of these, 1 (12.5%) had a positive SRA. Raw agreement between research coordinators and central adjudication on each domain of the 4Ts score and low, intermediate, and high PTP was good. However, chance-corrected agreement was variable between adjudicators (weighted κ values of 0.31-0.93) and between the adjudicator consensus and research coordinators (weighted κ values of 0.13 and 0.78). Post hoc review of the 6 SRA-positive cases with an adjudicated low PTP demonstrated that their scores would have been increased if the adjudicators had had additional information on heparin exposure prior to ICU admission. In general, the fourth domain of 4Ts (oTher causes of thrombocytopenia) generated the most disagreement. CONCLUSIONS: Real-time 4Ts scoring by research coordinators at the time of testing for HIT was not consistent with 4Ts scores obtained by central adjudicators. The results of this comprehensive HIT testing highlight the need for further research to improve the assessment of PTP scoring of HIT for critically ill patients.

A randomized double-blind placebo-controlled dose-escalation phase 1 study of aerosolized amikacin and fosfomycin delivered via the PARI investigational eFlow® inline nebulizer system in mechanically ventilated patients.

BACKGROUND: This clinical trial evaluated the pharmacokinetics and safety/tolerability of amikacin/fosfomycin solution using a vibrating plate nebulizer, in mechanically ventilated patients with ventilator-associated tracheobronchitis (VAT) or ventilator-associated pneumonia (VAP). METHODS: Nine adult patients were consented to receive three escalating doses of a combination of 50 mg/mL amikacin and 20 mg/mL fosfomycin; doses were separated by 24±2 hr. On day 3, patients received two blinded, randomized treatments (amikacin/fosfomycin and volume-matched placebo), separated by 2 hr. All treatments were administered with a single-patient, multitreatment nebulizer (Investigational eFlow(®) Inline Nebulizer System; PARI Pharma GmbH, positioned in the inspiratory limb tubing between the ventilator and the patient. The nebulizer remained in-line until all treatments had been delivered. Concentrations of amikacin and fosfomycin were measured in tracheal aspirate and plasma samples obtained during the 24 hr after each dose. RESULTS: Fifteen minutes after dosing with the 300/120 mg amikacin/fosfomycin combination, tracheal aspirate amikacin concentrations±SD were 12,390±3,986 µg/g, and fosfomycin concentrations were 6,174±2,548 µg/g (n=6). Airway clearance was rapid. Plasma concentrations were subtherapeutic; the highest observed amikacin plasma concentration was 1.4 µg/mL, and the highest observed fosfomycin plasma concentration was 0.8 µg/mL. Administration time was approximately 2 min/mL. No adverse effects on respiratory rate, peak airway pressures, or oxygenation were observed during or following drug or placebo administration. CONCLUSIONS: High tracheal aspirate concentrations of amikacin and fosfomycin were achieved in mechanically ventilated patients with VAT or VAP after aerosolized administration with an inline nebulizer system. Airway clearance was rapid. No adverse respiratory effects were noted during or following drug administration.

Co-enrollment of critically ill patients into multiple studies: patterns, predictors and consequences.

INTRODUCTION: Research on co-enrollment practices and their impact are limited in the ICU setting. The objectives of this study were: 1) to describe patterns and predictors of co-enrollment of patients in a thromboprophylaxis trial, and 2) to examine the consequences of co-enrollment on clinical and trial outcomes. METHODS: In an observational analysis of an international thromboprophylaxis trial in 67 ICUs, we examined the co-enrollment of critically ill medical-surgical patients into more than one study, and examined the clinical and trial outcomes among co-enrolled and non-co-enrolled patients. RESULTS: Among 3,746 patients enrolled in PROTECT (Prophylaxis for ThromboEmbolism in Critical Care Trial), 713 (19.0%) were co-enrolled in at least one other study (53.6% in a randomized trial, 37.0% in an observational study and 9.4% in both). Six factors independently associated with co-enrollment (all P < 0.001) were illness severity (odds ratio (OR) 1.35, 95% confidence interval (CI) 1.19 to 1.53 for each 10-point Acute Physiology and Chronic Health Evaluation (APACHE) II score increase), substitute decision-makers providing consent, rather than patients (OR 3.31, 2.03 to 5.41), experience of persons inviting consent (OR 2.67, 1.74 to 4.11 for persons with > 10 years' experience compared to persons with none), center size (all ORs > 10 for ICUs with > 15 beds), affiliation with trials groups (OR 5.59, 3.49 to 8.95), and main trial rather than pilot phase (all ORs > 8 for recruitment year beyond the pilot). Co-enrollment did not influence clinical or trial outcomes or risk of adverse events. CONCLUSIONS: Co-enrollment was strongly associated with features of the patients, research personnel, setting and study. Co-enrollment had no impact on trial results, and appeared safe, acceptable and feasible. Transparent reporting, scholarly discourse, ethical analysis and further research are needed on the complex topic of co-enrollment during critical illness.

Albumin resuscitation for traumatic brain injury: is intracranial hypertension the cause of increased mortality?

Mortality is higher in patients with traumatic brain injury (TBI) resuscitated with albumin compared with saline, but the mechanism for increased mortality is unknown. In patients from the Saline vs. Albumin Fluid Evaluation (SAFE) study with TBI who underwent intracranial pressure (ICP) monitoring, interventional data were collected from randomization to day 14 to determine changes in ICP (primary outcome) and in therapies used to treat increased ICP. Pattern mixture modelling, designed to address informative dropouts, was used to compare temporal changes between the albumin and saline groups, and 321 patients were identified, of whom 164 (51.1%) received albumin and 157 (48.9%) received saline. There was a significant linear increase in mean ICP and significantly more deaths in the albumin group compared with saline when ICP monitoring was discontinued during the first week (1.30±0.33 vs. -0.37±0.36, p=0.0006; and 34.4% vs. 17.4%; p=0.006 respectively), but not when monitoring ceased during the second week (-0.08±0.44 vs. -0.23±0.38, p=0.79; and 18.6% vs. 12.1%; p=0.36 respectively). There were statistically significant differences in the mean total daily doses of morphine (-0.42±0.07 vs. -0.66±0.0, p=0.0009), propofol (-0.45±0.11 vs. -0.76±0.11; p=0.034) and norepinephrine (-0.50±0.07 vs. -0.74±0.07) and in temperature (0.03±0.03 vs. 0.16±0.03; p=0.0014) between the albumin and saline groups when ICP monitoring ceased during the first week. The use of albumin for resuscitation in patients with severe TBI is associated with increased ICP during the first week. This is the most likely mechanism of increased mortality in these patients.

Rates and determinants of informed consent: a case study of an international thromboprophylaxis trial.

BACKGROUND: Successful completion of randomized trials depends upon efficiently and ethically screening patients and obtaining informed consent. Awareness of modifiable barriers to obtaining consent may inform ongoing and future trials. OBJECTIVE: The objective of this study is to describe and examine determinants of consent rates in an international heparin thromboprophylaxis trial (Prophylaxis for ThromboEmbolism in Critical Care Trial, clinicaltrials.gov NCT00182143). DESIGN: Throughout the 4-year trial, research personnel approached eligible critically ill patients or their substitute decision makers for informed consent. Whether consent was obtained or declined was documented daily. SETTING: The trial was conducted in 67 centers in 6 countries. MEASUREMENTS AND MAIN RESULTS: A total of 3764 patients were randomized. The overall consent rate was 82.2% (range, 50%-100%) across participating centers. Consent was obtained from substitute decision makers and patients in 90.1% and 9.9% of cases, respectively. Five factors were independently associated with consent rates. Research coordinators with more experience achieved higher consent rates (odds ratio [OR], 3.43; 95% confidence interval, 2.42-4.86; P < .001 for those with >10 years of experience). Consent rates were higher in smaller intensive care units with less than 15 beds compared with intensive care units with 15 to 20 beds, 21 to 25 beds, and greater than 25 beds (all ORs, <0.5; P < .001) and were higher in centers with more than 1 full-time research staff (OR, 1.95; 95% confidence interval, 1.28-2.99; P < .001). Consent rates were lower in centers affiliated with the Canadian Critical Care Trials Group or the Australian and New Zealand Intensive Care Society Clinical Trials Group compared with other centers (OR, 0.57; 95% confidence interval, 0.42-0.77; P < .001). Finally, consent rates were highest during the pilot trial, lowest during the initiation of the full trial, and increased over years of recruitment (P < .001). CONCLUSIONS: Characteristics of study centers, research infrastructure, and experience were important factors associated with successfully procuring informed consent to participate in this thromboprophylaxis trial.

Research ethics board approval for an international thromboprophylaxis trial.

BACKGROUND: Research ethics board (REB) review of scientific protocols is essential, ensuring participants' dignity, safety, and rights. The objectives of this study were to examine the time from submission to approval, to analyze predictors of approval time, and to describe the scope of conditions from REBs evaluating an international thromboprophylaxis trial. METHODS: We generated survey items through literature review and investigators' discussions, creating 4 domains: respondent and institutional demographics, the REB application process, and alternate consent models. We conducted a document analysis that involved duplicate assessment of themes from REB critique of the protocol and informed consent forms (ICF). RESULTS: Approval was granted from 65 REB institutions, requiring 58 unique applications. We analyzed 44 (75.9%) of 58 documents and surveys. Survey respondents completing the applications had 8 (5-12) years of experience; 77% completed 4 or more REB applications in previous 5 years. Critical care personnel were represented on 54% of REBs. The time to approval was a median (interquartile range) of 75 (42, 150) days, taking longer for sites with national research consortium membership (89.1 vs 31.0 days, P = .03). Document analysis of the application process and ICF yielded 5 themes: methodology, data management, consent procedures, cataloguing, and miscellaneous. Protocol-specific themes focused on trial implementation, external critiques, and budget. The only theme specific to the ICF was risks and benefits. The most frequent comments on the protocol and ICF were about methodology and miscellaneous issues; ICF comments also addressed study risks and benefits. CONCLUSIONS: More studies on methods to enhance efficiency and consistency of the REB approval processes for clinical trials are needed while still maintaining high ethical standards.