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Background: To our knowledge, the use and management of pressure support ventilation (PSV) in patients receiving prolonged (≥ 7 days) invasive mechanical ventilation has not previously been described. Objective: To collect and analyse data on the use and management of PSV in critically ill patients receiving prolonged ventilation. Design, setting and participants: We performed a multicentre retrospective observational study in Australia, with a focus on PSV in patients ventilated for ≥ 7 days. Main outcome measures: We obtained detailed data on ventilator management twice daily (8am and 8pm moments) for the first 7 days of ventilation. Results: Among 143 consecutive patients, 90/142 (63.4%) had received PSV by Day 7, and PSV accounted for 40.5% (784/1935) of ventilation moments. The most common pressure support level was 10 cmH 2 O (352/780) observations [45.1%]) with little variation over time, and 37 of 114 patients (32.4%) had no change in pressure support. Mean tidal volume during PSV was 8.3 (7.0-9.5) mL/kg predicted bodyweight (PBW) compared with 7.5 (7.0-8.3) mL/kg PBW during mandatory ventilation (P < 0.001). For 74.6% (247/331) of moments, despite a tidal volume of more than 8 mL/kg PBW, the pressure support level was not changed. Among 122 patients exposed to PSV, 97 (79.5%) received likely over-assistance according to rapid shallow breathing index criteria. Of 784 PSV moments, 411 (52.4%) were also likely over-assisted according to rapid shallow breathing index criteria, and 269/346 (77.7%) having no subsequent adjustment of pressure support. Conclusions: In patients receiving prolonged ventilation, almost two-thirds received PSV, which accounted for 40.5% of mechanical ventilation time. Half of the PSV-treated patients were exposed to high tidal volume and two-thirds to likely over-assistance. These observations provide evidence that can be used to inform interventional studies of PSV management., Competing Interests: No relevant disclosures., (© 2021 College of Intensive Care Medicine of Australia and New Zealand.)

Objective: There is a need for evidence on the best sedative agents in children undergoing open heart surgery for congenital heart disease. This study aimed to evaluate the feasibility and safety of dexmedetomidine in this group compared with midazolam., Design: Double blinded, pilot randomized controlled trial., Setting: Cardiac operating theatre and paediatric intensive care unit in Brisbane, Australia., Participants: Infants (≤12 months of age) undergoing their first surgical repair of a congenital heart defect., Interventions: Dexmedetomidine (up to 1.0mcg/kg/hr) versus midazolam (up to 80mcg/kg/hr), commenced in the cardiac operating theatre prior to surgery., Main Outcome Measures: The primary outcome was the time spent in light sedation (Sedation Behavior Scale [SBS] -1 to +1); Co-primary feasibility outcome was recruitment, retention and protocol adherence. Secondary outcomes were use of supplemental sedatives, ventilator free days, delirium, vasoactive drug support, and adverse events. Neurodevelopment and health-related quality of life (HRQoL) were assessed at 12 months post-surgery., Results: Sixty-six participants were recruited. The number of SBS scores in the light sedation range were greater in the dexmedetomidine group at 24 hours, 48 hours, and overall study duration (0-14 days) versus the midazolam group (24hr: 76/170 [45%] vs 60/178 [34%], aOR 4.14 [95% CI 0.48, 35.92]; 48hr: 154/298 [52%] vs 122/314 [39%], aOR 6.95 [95% CI 0.77, 63.13]; 0-14 days: 597/831 [72%] vs 527/939 [56%], aOR 3.93 [95% CI 0.62, 25.03]). Feasibility was established with no withdrawals or loss to follow-up at 14 days and minimal protocol deviations. There were no differences between the groups relating to clinical, safety, neurodevelopment or HRQoL outcomes., Conclusions: The use of dexmedetomidine was associated with more time spent in light sedation when compared with midazolam. The feasibility of conducting a blinded RCT of midazolam and dexmedetomidine in children undergoing open heart surgery was also established. The findings justify further investigation in a larger trial., Clinical Trial Registration: ACTRN12615001304527., (© 2023 Published by Elsevier B.V. on behalf of College of Intensive Care Medicine of Australia and New Zealand.)

Background: Septic shock is associated with poor outcomes. Vitamin C (ascorbic acid) is a cellular antioxidant and has anti-inflammatory properties. Whether the combination therapy of vitamin C, thiamine and hydrocortisone reduces vasopressor dependency in septic shock is unclear., Objectives: To describe the protocol and statistical analysis plan of a multicentre, open-label, prospective, phase 2 randomised clinical trial evaluating the effects of vitamin C, thiamine and hydrocortisone when compared with hydrocortisone monotherapy on the duration of vasopressor administration in critically ill patients with septic shock., Methods: VITAMINS is a multicentre cardiovascular efficacy trial in adult patients with septic shock. Randomisation occurs via a secure website with stratification by site, and allocation concealment is maintained throughout the trial. The primary outcome is the duration of time alive and free of vasopressor administration at Day 7. Secondary outcomes include feasibility endpoints and some patientcentred outcomes. All analyses will be conducted on an intention-to-treat basis., Conclusion: The VITAMINS trial will determine whether combination therapy of vitamin C, thiamine and hydrocortisone when compared with hydrocortisone increases vasopressor-free hours in critically ill patients with septic shock. The conduct of this study will provide important information on the feasibility of studying this intervention in a phase 3 trial., Trial Registration: ClinicalTrials.gov, identification No. NCT03333278.

Objective: To evaluate the prevalence of "likely overassistance" (categorised by respiratory rate [RR] ≤ 17 breaths/min or rapid shallow breathing index [RSBI] ≤ 37 breaths/min/L) during invasive pressure support ventilation (PSV), and the additional prevalence of fixed ventilator settings., Design: Multicentre prospective observational study of invasive PSV practice in six general Victorian intensive care units with blinding of staff members to data collection., Patients: At each hospital, investigators collected data between 11 am and 2 pm on all invasive PSV-treated patients on 60 sequential days, excluding weekends and public holidays, between 22 February and 30 August 2017. Each patient was included for maximum of 3 days., Main Results: We studied 231 patients, with a total of 379 observations episodes over the study period. There were 131 patients (56.7%) with at least one episode of RR ≤ 17 breaths/min; 146 patients (63.2%) with at least one episode of RSBI ≤ 37 breaths/min/L, and 85 patients (36.8%) with at least one episode of combined RR ≤ 17 breaths/min and RSBI ≤ 37 breaths/min/L. Moreover, the total number of observations with "likely overassistance" (RR ≤ 17 or RSBI ≤ 37 breaths/min/L) was 178 (47%) and 204 (53.8%), respectively; while for both combined criteria, it was 154 (40.6%). We also found that 10 cmH 2 O pressure support was delivered on 210 of the observations (55.4%) and adjusted in less than 25% of observations. Finally, less than half (179 observations) of all PSV-delivered tidal volumes (V T ) were at the recommended value of 6-8 mL/kg predicted body weight (PBW) and more than 20% (79 observations) were at ≥ 10 mL/kg PBW., Conclusion: In a cohort of Victorian hospitals in Australia, during invasive PSV, "likely overassistance" was common, and the pressure support level was delivered in a standardised and unadjusted manner at 10 cmH 2 O, resulting in the frequent delivery of potentially injurious V T .

Background: Sedation strategy in critically ill patients who are mechanically ventilated is influenced by patient-related factors, choice of sedative agent and the intensity or depth of sedation prescribed. The impact of sedation strategy on outcome, in particular when delivered early after initiation of mechanical ventilation, is uncertain., Objectives: To present the protocol and analysis plan of a large randomised clinical trial investigating the effect of a sedation strategy, in critically ill patients who are mechanically ventilated, based on a protocol targeting light sedation using dexmedetomidine as the primary sedative, termed "early goal-directed sedation", compared with usual practice., Methods: This is a multinational randomised clinical trial in adult intensive care patients expected to require mechanical ventilation for longer than 24 hours. The main exclusion criteria include suspected or proven primary brain pathology or having already been intubated or sedated in an intensive care unit for longer than 12 hours. Randomisation occurs via a secured website with baseline stratification by site and suspected or proven sepsis. The primary outcome is 90-day all-cause mortality. Secondary outcomes include death, institutional dependency, cognitive function and health-related quality of life 180 days after randomisation, as well as deliriumfree, coma-free and ventilation-free days at 28 days after randomisation. A predefined subgroup analysis will also be conducted. Analyses will be on an intention-to-treat basis and in accordance with this pre-specified analysis plan., Conclusion: SPICE III is an ongoing large scale clinical trial. Once completed, it will inform sedation practice in critically ill patients who are ventilated.

Objectives: To determine the impact of the intensity of early correction of hyperglycaemia on outcomes in patients with diabetic ketoacidosis (DKA) admitted to the intensive care unit., Methods: We studied adult patients with DKA admitted to 171 ICUs in Australia and New Zealand from 2000 to 2013. We used their blood glucose levels (BGLs) in the first 24 hours after ICU admission to determine whether intensive early correction of hyperglycemia to ≤ 180 mg/dL was independently associated with hypoglycaemia, hypokalaemia, hypo-osmolarity or mortality, compared with partial early correction to > 180 mg/dL as recommended by DKA-specific guidelines., Results: Among 8553 patients, intensive early correction of BGL was applied to 605 patients (7.1%). A greater proportion of these patients experienced hypoglycaemia (20.2% v 9.1%; P < 0.001) and/or hypo-osmolarity (29.4% v 22.0%; P < 0.001), but not hypokalaemia (16.7% v 15.6%; P = 0.47). Overall, 11 patients (1.8%) in the intensive correction group and 112 patients (1.4%) in the partial correction group died (P = 0.42). However, after adjustment for illness severity, partial early correction of BGL was independently associated with a lower risk of hypoglycaemia (odds ratio [OR], 0.38; 95% CI, 0.30-0.48; P < 0.001), lower risk of hypo-osmolarity (OR, 0.80; 95% CI, 0.65-0.98; P < 0.03) and lower risk of death (OR, 0.44; 95% CI, 0.22-0.86; P = 0.02)., Conclusions: In a large cohort of patients with DKA, partial early correction of BGL according to DKA-specific guidelines, when compared with intensive early correction of BGL, was independently associated with a lower risk of hypoglycaemia, hypo-osmolarity and death.

The Australian and New Zealand Intensive Care Society Clinical Trials Group and other investigator-led trials groups in critical care publish policies and guidelines outlining the rationale for considering co-enrolment in large, randomised controlled trials in intensive care medicine. However, none present a checklist of criteria by which a request for permission to co-enrol in an existing trial can be assessed. Consequently, such requests tend to be made and assessed on an ad hoc basis. Based on our experience in the SPICE III randomised controlled trial, we propose eight broadly applicable criteria (the SPICE-8 criteria) to be satisfied before co-enrolment should be approved. Reporting co-enrolment in trials, for regulatory purposes and in publications, is uncommon, partly because of the complexity involved in explaining a lack of a plausible coenrolment effect. We suggest that noting compliance with these criteria would simplify such reporting and enhance transparency.

Objective: Trials in critical care have previously used unvalidated systems to classify cause of death. We aimed to provide initial validation of a method to classify cause of death in intensive care unit patients., Design, Setting and Participants: One hundred case scenarios of patients who died in an ICU were presented online to raters, who were asked to select a proximate and an underlying cause of death for each, using the ICU Deaths Classification and Reason (ICU-DECLARE) system. We evaluated two methods of categorising proximate cause of death (designated Lists A and B) and one method of categorising underlying cause of death. Raters were ICU specialists and research coordinators from Australia, New Zealand and the United Kingdom., Main Outcome Measures: Inter-rater reliability, as measured by the Fleiss multirater kappa, and the median proportion of raters choosing the most likely diagnosis (defined as the most popular classification choice in each case)., Results: Across all raters and cases, for proximate cause of death List A, kappa was 0.54 (95% CI, 0.49-0.60), and for proximate cause of death List B, kappa was 0.58 (95% CI, 0.53-0.63). For the underlying cause of death, kappa was 0.48 (95% CI, 0.44-0.53). The median proportion of raters choosing the most likely diagnosis for proximate cause of death, List A, was 77.5% (interquartile range [IQR], 60.0%-93.8%), and the median proportion choosing the most likely diagnosis for proximate cause of death, List B, was 82.5% (IQR, 60.0%-92.5%). The median proportion choosing the most likely diagnosis for underlying cause was 65.0% (IQR, 50.0%-81.3%). Kappa and median agreement were similar between countries. ICU specialists showed higher kappa and median agreement than research coordinators., Conclusions: The ICU-DECLARE system allowed ICU doctors to classify the proximate cause of death of patients who died in the ICU with substantial reliability.

Objective: To examine practice patterns and workload of practising Australian intensivists and to investigate the risk and prevalence of "burnout syndrome"., Design and Setting: On-line survey was emailed to 324 intensivists listed on the database of the Australian and New Zealand Intensive Care Society (ANZICS) and practising in Australia., Main Outcome Measures: Prospectively recorded workload during a specific week in October 2007, self-reported 12-weekly averaged work pattern, and prevalence of burnout syndrome assessed by modified Maslach Burnout Inventory-General Survey (MBI-GS)., Results: 115 intensivists (36%) responded; respondents were representative of mainstream tertiary intensive care practitioners. On average in a 12-week period, intensivists spent 42% of working days in bedside patient management, 16% in administration, 11% in locum positions, 9% in research and 9% in recreational leave. During 1 week of prospective recording of actual workload, 26% of intensivists managed more than nine ventilated patients, and most admitted more than two new patients per day. Most were involved in more than two family conferences with a median duration of 1 h. The MBI-GS showed that 80% of respondents had signs of psychological stress and discomfort, 42% showed signs of emotional exhaustion, 32% had negative feelings and cynicism, and 37% considered they underachieved in terms of personal accomplishments., Conclusions: Intensivists are at high risk of burnout syndrome. Recognising the drivers and early signs of burnout and identifying a preventive strategy is a professional priority for ANZICS and the intensive care community.