Conservative Oxygen Therapy during Mechanical Ventilation in the ICU.

BACKGROUND: Patients who are undergoing mechanical ventilation in the intensive care unit (ICU) often receive a high fraction of inspired oxygen (Fio2) and have a high arterial oxygen tension. The conservative use of oxygen may reduce oxygen exposure, diminish lung and systemic oxidative injury, and thereby increase the number of ventilator-free days (days alive and free from mechanical ventilation). METHODS: We randomly assigned 1000 adult patients who were anticipated to require mechanical ventilation beyond the day after recruitment in the ICU to receive conservative or usual oxygen therapy. In the two groups, the default lower limit for oxygen saturation as measured by pulse oximetry (Spo2) was 90%. In the conservative-oxygen group, the upper limit of the Spo2 alarm was set to sound when the level reached 97%, and the Fio2 was decreased to 0.21 if the Spo2 was above the acceptable lower limit. In the usual-oxygen group, there were no specific measures limiting the Fio2 or the Spo2. The primary outcome was the number of ventilator-free days from randomization until day 28. RESULTS: The number of ventilator-free days did not differ significantly between the conservative-oxygen group and the usual-oxygen group, with a median duration of 21.3 days (interquartile range, 0 to 26.3) and 22.1 days (interquartile range, 0 to 26.2), respectively, for an absolute difference of -0.3 days (95% confidence interval [CI], -2.1 to 1.6; P = 0.80). The conservative-oxygen group spent more time in the ICU with an Fio2 of 0.21 than the usual-oxygen group, with a median duration of 29 hours (interquartile range, 5 to 78) and 1 hour (interquartile range, 0 to 17), respectively (absolute difference, 28 hours; 95% CI, 22 to 34); the conservative-oxygen group spent less time with an Spo2 exceeding 96%, with a duration of 27 hours (interquartile range, 11 to 63.5) and 49 hours (interquartile range, 22 to 112), respectively (absolute difference, 22 hours; 95% CI, 14 to 30). At 180 days, mortality was 35.7% in the conservative-oxygen group and 34.5% in the usual-oxygen group, for an unadjusted odds ratio of 1.05 (95% CI, 0.81 to 1.37). CONCLUSIONS: In adults undergoing mechanical ventilation in the ICU, the use of conservative oxygen therapy, as compared with usual oxygen therapy, did not significantly affect the number of ventilator-free days. (Funded by the Health Research Council of New Zealand; ICU-ROX Australian and New Zealand Clinical Trials Registry number, ACTRN12615000957594.).

The Effect of a Liberal Approach to Glucose Control in Critically Ill Patients with Type 2 Diabetes: A Multicenter, Parallel-Group, Open-Label Randomized Clinical Trial.

Rationale: Blood glucose concentrations affect outcomes in critically ill patients, but the optimal target blood glucose range in those with type 2 diabetes is unknown. Objectives: To evaluate the effects of a "liberal" approach to targeted blood glucose range during ICU admission. Methods: This mutlicenter, parallel-group, open-label randomized clinical trial included 419 adult patients with type 2 diabetes expected to be in the ICU on at least three consecutive days. In the intervention group intravenous insulin was commenced at a blood glucose >252 mg/dl and titrated to a target range of 180-252 mg/dl. In the comparator group insulin was commenced at a blood glucose >180 mg/dl and titrated to a target range of 108-180 mg/dl. The primary outcome was incident hypoglycemia (<72 mg/dl). Secondary outcomes included glucose metrics and clinical outcomes. Measurements and Main Results: By Day 28, at least one episode of hypoglycemia occurred in 10 of 210 (5%) patients assigned the intervention and 38 of 209 (18%) patients assigned the comparator (incident rate ratio, 0.21 [95% confidence interval (CI), 0.09 to 0.49]; P < 0.001). Those assigned the intervention had greater blood glucose concentrations (daily mean, minimum, maximum), less glucose variability, and less relative hypoglycemia (P < 0.001 for all comparisons). By Day 90, 62 of 210 (29.5%) in the intervention and 52 of 209 (24.9%) in the comparator group had died (absolute difference, 4.6 percentage points [95% CI, -3.9% to 13.2%]; P = 0.29). Conclusions: A liberal approach to blood glucose targets reduced incident hypoglycemia but did not improve patient-centered outcomes. Clinical trial registered with Australian New Zealand Clinical Trials Registry (ACTRN 12616001135404).

A Multicenter, Open-Label, Randomized Controlled Trial of a Conservative Fluid Management Strategy Compared With Usual Care in Participants After Cardiac Surgery: The Fluids After Bypass Study.

OBJECTIVES: There is little evidence to guide fluid administration to patients admitted to the ICU following cardiac surgery. This study aimed to determine if a protocolized strategy known to reduce fluid administration when compared with usual care reduced ICU length of stay following cardiac surgery. DESIGN: Prospective, multicenter, parallel-group, randomized clinical trial. SETTING: Five cardiac surgical centers in New Zealand conducted from November 2016 to December 2018 with final follow-up completed in July 2019. PATIENTS: Seven-hundred fifteen patients undergoing cardiac surgery; 358 intervention and 357 usual care. INTERVENTIONS: Randomization to protocol-guided strategy utilizing stroke volume variation to guide administration of bolus fluid or usual care fluid administration until desedation or up to 24 hours. Primary outcome was length of stay in ICU. Organ dysfunction, mortality, process of care measures, patient-reported quality of life, and disability-free survival were collected up to day 180. MEASUREMENTS AND MAIN RESULTS: Overall 666 of 715 (93.1%) received at least one fluid bolus. Patients in the intervention group received less bolus fluid (median [interquartile range], 1,000 mL [250-2,000 mL] vs 1,500 mL [500-2,500 mL]; p < 0.0001) and had a lower overall fluid balance (median [interquartile range], 319 mL [-284 to 1,274 mL] vs 673 mL [38-1,641 mL]; p < 0.0001) in the intervention period. There was no difference in ICU length of stay between the two groups (27.9 hr [21.8-53.5 hr] vs 25.6 hr [21.9-64.6 hr]; p = 0.95). There were no differences seen in development of organ dysfunction, quality of life, or disability-free survival at any time points. Hospital mortality was higher in the intervention group (4% vs 1.4%; p = 0.04). CONCLUSIONS: A protocol-guided strategy utilizing stroke volume variation to guide administration of bolus fluid when compared with usual care until desedation or up to 24 hours reduced the amount of fluid administered but did not reduce the length of stay in ICU.

Using cardiac output monitoring to guide perioperative haemodynamic therapy.

PURPOSE OF REVIEW: The aim of this study was to review recent advances and evidence for the use of cardiac output monitors to guide perioperative haemodynamic therapy. RECENT FINDINGS: There are multiple different cardiac output monitoring devices available for clinical use which are coupled with many different intervention protocols to manipulate perioperative haemodynamics. There is little evidence to demonstrate superiority of any one device. Previous small studies and meta-analyses have suggested that perioperative haemodynamic therapy guided by cardiac output monitoring improves outcomes after major surgery. Despite relatively low-quality evidence several national bodies have recommended 'perioperative goal-directed therapy' (GDT) as a standard of care.Recent larger trials of GDT have mostly failed to prove a benefit of GDT and one explanation for this is the increased quality of usual care that may be occurring because of initiatives such as enhanced recovery after surgery and the WHO Safer Surgery programmes. SUMMARY: Perioperative GDT remains an exciting intervention to reduce significant morbidity following major surgery; however, it is not yet a proven standard of care. Further large pragmatic trials are required to demonstrate its effectiveness particularly in the era of enhanced recovery after surgery programmes.

Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) randomised clinical trial: study protocol.

INTRODUCTION: Bloodstream infections are a leading cause of mortality and morbidity; the duration of treatment for these infections is understudied. METHODS AND ANALYSIS: We will conduct an international, multicentre randomised clinical trial of shorter (7 days) versus longer (14 days) antibiotic treatment among hospitalised patients with bloodstream infections. The trial will include 3626 patients across 60 hospitals and 6 countries. We will include patients with blood cultures confirming a pathogenic bacterium after hospital admission. Exclusion criteria will include patient factors (severe immunosuppression), infection site factors (endocarditis, osteomyelitis, undrained abscesses, infected prosthetic material) and pathogen factors (Staphylococcus aureus, Staphylococcus lugdunensis, Candida and contaminant organisms). We will leave the selection of specific antibiotics, doses and route of delivery to the discretion of treating physicians; no placebo control will be used given the diversity of pathogens and sources of bacteraemia. The intervention will be assignment of treatment duration to be 7 versus 14 days. We will minimise selection bias via central randomisation with variable block sizes, with concealed allocation until day 7 of adequate antibiotic treatment. The primary outcome is 90-day survival; we will test whether 7 days is non-inferior to 14 days of treatment, with a non-inferiority margin of 4% absolute mortality. Secondary outcomes include hospital and intensive care unit (ICU) mortality, relapse rates of bacteraemia, hospital and ICU length of stay, mechanical ventilation and vasopressor duration, antibiotic-free days, Clostridium difficile infection, antibiotic allergy and adverse events and colonisation/infection with antibiotic-resistant organisms. ETHICS AND DISSEMINATION: The study has been approved by the ethics review board at each participating site. Sunnybrook Health Sciences Centre is the central ethics committee. We will disseminate study results via the Canadian Critical Care Trials Group and other collaborating networks to set the global paradigm for antibiotic treatment duration for non-staphylococcal Gram-positive, Gram-negative and anaerobic bacteraemia, among patients admitted to hospital. TRIAL REGISTRATION NUMBER: The BALANCE (Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness) trial was registered at www.clinicaltrials.gov (registration number: NCT03005145).

Protocol summary and statistical analysis plan for the intensive care unit randomised trial comparing two approaches to oxygen therapy (ICU-ROX).

BACKGROUND: The balance of risks and benefits of conservative v standard care oxygen strategies for patients who are invasively ventilated in the intensive care unit (ICU) is uncertain. OBJECTIVE: To describe the study protocol and statistical analysis plan for the ICU randomised trial comparing two approaches to oxygen therapy (ICU-ROX). DESIGN, SETTING AND PARTICIPANTS: Protocol for a multicentre, randomised, participant and outcome assessor-blinded, standard care-controlled, parallel-group, two-sided superiority trial to be conducted in up to 22 ICUs in Australia and New Zealand. 1000 adults who are mechanically ventilated in the ICU and expected to remain ventilated beyond the day after recruitment will be randomly assigned to conservative oxygen therapy or standard care in a 1:1 ratio. ICU-ROX began with an internal pilot phase in September 2015. It is anticipated that recruitment will be completed in 2018. MAIN OUTCOME MEASURES: The primary endpoint will be alive, ventilator-free days to Day 28. Secondary outcomes include 90- and 180-day all-cause mortality, survival time to 180 days, and quality of life and cognitive function at 180 days. All analyses will be conducted on an intentionto- treat basis. RESULTS AND CONCLUSIONS: ICU-ROX will compare the effect of conservative v standard oxygen therapy in critically ill mechanically ventilated adults who are expected to be ventilated beyond the day after recruitment on ventilatorfree days to Day 28. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ANZCTRN 12615000957594).

Position paper for the organization of ECMO programs for cardiac failure in adults.

Extracorporeal membrane oxygenation (ECMO) has been used increasingly for both respiratory and cardiac failure in adult patients. Indications for ECMO use in cardiac failure include severe refractory cardiogenic shock, refractory ventricular arrhythmia, active cardiopulmonary resuscitation for cardiac arrest, and acute or decompensated right heart failure. Evidence is emerging to guide the use of this therapy for some of these indications, but there remains a need for additional evidence to guide best practices. As a result, the use of ECMO may vary widely across centers. The purpose of this document is to highlight key aspects of care delivery, with the goal of codifying the current use of this rapidly growing technology. A major challenge in this field is the need to emergently deploy ECMO for cardiac failure, often with limited time to assess the appropriateness of patients for the intervention. For this reason, we advocate for a multidisciplinary team of experts to guide institutional use of this therapy and the care of patients receiving it. Rigorous patient selection and careful attention to potential complications are key factors in optimizing patient outcomes. Seamless patient transport and clearly defined pathways for transition of care to centers capable of providing heart replacement therapies (e.g., durable ventricular assist device or heart transplantation) are essential to providing the highest level of care for those patients stabilized by ECMO but unable to be weaned from the device. Ultimately, concentration of the most complex care at high-volume centers with advanced cardiac capabilities may be a way to significantly improve the care of this patient population.