Haemodynamic changes during prone versus supine position in patients with COVID-19 acute respiratory distress syndrome.

Background: Prone positioning improves oxygenation in patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19. However, its haemodynamic effects are poorly understood.

Objectives: The objective of this study was to investigate the acute haemodynamic changes associated with prone position in mechanically ventilated patients with COVID-19 ARDS.

Intraoperative low tidal volume ventilation and the risk of ICD-10 coded delirium and the use for antipsychotic medications.

Background: Low tidal volume (V) ventilation and its associated increase in arterial carbon dioxide (PaCO) may affect postoperative neurologic function. We aimed to test the hypothesis that intraoperative low V ventilation affect the incidence of postoperative ICD-10 coded delirium and/or the need for antipsychotic medications.

Methods: This is a post-hoc analysis of a large randomized controlled trial evaluating low vs.

Reported definitions of intraoperative hypotension in adults undergoing non-cardiac surgery under general anaesthesia: a review.

Background: Intraoperative hypotension (IOH) during non-cardiac surgery is common and associated with major adverse kidney, neurological and cardiac events and even death. Given that IOH is a modifiable risk factor for the mitigation of postoperative complications, it is imperative to generate a precise definition for IOH to facilitate strategies for avoiding or treating its occurrence. Moreover, a universal and consensus definition of IOH may also facilitate the application of novel and emerging therapeutic interventions in treating IOH.

Intra-operative ventilator mechanical power as a predictor of postoperative pulmonary complications in surgical patients: A secondary analysis of a randomised clinical trial.

Background: Studies in critically ill patients suggest a relationship between mechanical power (an index of the energy delivered by the ventilator, which includes driving pressure, respiratory rate, tidal volume and inspiratory pressure) and complications.

Objective: We aimed to assess the association between intra-operative mechanical power and postoperative pulmonary complications (PPCs).

Design: Post hoc analysis of a large randomised clinical trial.

The association of acute hypercarbia and plasma potassium concentration during laparoscopic surgery: a retrospective observational study.

Background: It is uncertain whether increases in PaCO during surgery lead to an increase in plasma potassium concentration and, if so, by how much. Hyperkalaemia may result in cardiac arrhythmias, muscle weakness or paralysis. The key objectives were to determine whether increases in PaCO during laparoscopic surgery induce increases in plasma potassium concentrations and, if so, to determine the magnitude of such changes.

Effect of Intraoperative Low Tidal Volume vs Conventional Tidal Volume on Postoperative Pulmonary Complications in Patients Undergoing Major Surgery: A Randomized Clinical Trial.

Importance: In patients who undergo mechanical ventilation during surgery, the ideal tidal volume is unclear.

Objective: To determine whether low-tidal-volume ventilation compared with conventional ventilation during major surgery decreases postoperative pulmonary complications.

Design, Setting, And Participants: Single-center, assessor-blinded, randomized clinical trial of 1236 patients older than 40 years undergoing major noncardiothoracic, nonintracranial surgery under general anesthesia lasting more than 2 hours in a tertiary hospital in Melbourne, Australia, from February 2015 to February 2019.

Frequency of hyperoxaemia during and after major surgery.

The oxygen concentration (FiO) and arterial oxygen tension (PaO) delivered in patients undergoing major surgery is poorly understood. We aimed to assess current practice with regard to the delivered FiO and the resulting PaO in patients undergoing major surgery. We performed a retrospective cohort study in a tertiary hospital.

Randomised controlled trial to investigate the relationship between mild hypercapnia and cerebral oxygen saturation in patients undergoing major surgery.

Objectives: The effects of hypercapnia on regional cerebral oxygen saturation (rSO) during surgery are unclear. We conducted a randomised controlled trial to investigate the relationship between mild hypercapnia and rSO. We hypothesised that, compared with targeted normocapnia (TN), targeted mild hypercapnia (TMH) during major surgery would increase rSO.

Relationship between acute hypercarbia and hyperkalaemia during surgery.

Background: The relationship between hyperkalaemia and metabolic acidosis is well described in the critical care setting; however, the relationship between acute respiratory acidosis and plasma potassium concentration is less well understood. In a controlled model of increasing levels of hypercarbia, we tested the hypothesis of whether increasing levels of hypercarbia are associated with changes in plasma potassium concentrations.

Aim: To determine whether increasing levels of hypercarbia are associated with changes in plasma potassium concentrations.

Low tidal volume ventilation during anaesthesia for major surgery: protocol and statistical analysis plan.

Background: Mechanical ventilation is mandatory in patients undergoing general anaesthesia for major surgery. Tidal volumes higher than 10 mL/kg of predicted body weight have been advocated for intraoperative ventilation, but recent evidence suggests that low tidal volumes may benefit surgical patients. To date, the impact of low tidal volume compared with conventional tidal volume during surgery has only been assessed in clinical trials that also combine different levels of positive end-expiratory pressure (PEEP) in each arm.

Intensive care implications of epidemic thunderstorm asthma.

Objective: To investigate the environmental precipitants, treatment and outcome of critically ill patients affected by the largest and most lethal reported epidemic of thunderstorm asthma.

Design, Setting And Participants: Retrospective multicentre observational study. Meteorological, airborne particulate and pollen data, and a case series of 35 patients admitted to 15 intensive care units (ICUs) due to the thunderstorm asthma event of 21-22 November 2016, in Victoria, Australia, were analysed and compared with 1062 total ICU-admitted Australian patients with asthma in 2016.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors.

Background: A multidisciplinary collaboration investigated the world's largest, most catastrophic epidemic thunderstorm asthma event that took place in Melbourne, Australia, on Nov 21, 2016, to inform mechanisms and preventive strategies.

Methods: Meteorological and airborne pollen data, satellite-derived vegetation index, ambulance callouts, emergency department presentations, and data on hospital admissions for Nov 21, 2016, as well as leading up to and following the event were collected between Nov 21, 2016, and March 31, 2017, and analysed. We contacted patients who presented during the epidemic thunderstorm asthma event at eight metropolitan health services (each including up to three hospitals) via telephone questionnaire to determine patient characteristics, and investigated outcomes of intensive care unit (ICU) admissions.

Ventilation management in Victorian intensive care unit patients without acute respiratory distress syndrome.

Background: The setting of tidal volume (V) during controlled mechanical ventilation (CMV) in critically ill patients without acute respiratory distress syndrome (ARDS) is likely important but currently unknown. We aimed to describe current CMV settings in intensive care units (ICUs) across Victoria.

Methods: We performed a multicentre, prospective, observational study.

Predicting intensive care and hospital outcome with the Dalhousie Clinical Frailty Scale: a pilot assessment.

Frailty may help to predict intensive care unit (ICU) patient outcome. The Dalhousie Clinical Frailty Scale (DCFS) is validated to assess frailty in ambulatory settings but has not been investigated in Australian ICUs. We conducted a prospective three-month study of patients admitted to a tertiary level ICU.

Current ventilation practice during general anaesthesia: a prospective audit in Melbourne, Australia.

Background: Recent evidence suggests that the use of low tidal volume ventilation with the application of positive end-expiratory pressure (PEEP) may benefit patients at risk of respiratory complications during general anaesthesia. However current Australian practice in this area is unknown.

Methods: To describe current practice of intraoperative ventilation with regard to tidal volume and application of PEEP, we performed a multicentre audit in patients undergoing general anaesthesia across eight teaching hospitals in Melbourne, Australia.