Utility of venous blood gases for the assessment of traumatic shock: a prospective observational study.

BACKGROUND: ABG samples are often obtained in trauma patients to assess shock severity. Venous blood gas (VBG) sampling, which is less invasive, has been widely used to assess other forms of shock. The study aim was to determine the agreement between VBG and ABG measurements in trauma. METHODS: Patients were enrolled at an Australian trauma centre between October 2016 and October 2018. Bland-Altman limits of agreement (LOA) between paired blood gas samples taken <30 min apart were used to quantify the extent of agreement. The impact of using only VBG measurements was considered using an a priori plan. Cases where venous sampling failed to detect 'concerning levels' were flagged using evidence-based cut-offs: pH ≤7.2, base deficit (BD) ≤-6, bicarbonate <21 and lactate ≥4. Case summaries of these patients were assessed by independent trauma clinicians as to whether an ABG would change expected management. RESULTS: During the study period 176 major trauma patients had valid paired blood gas samples available for analysis. The median time difference between paired measurements was 11 min (IQR 6-17). There was a predominance of men (81.8%) and blunt trauma (92.0%). Median Injury Severity Score was 13 (range 1-75) and inpatient mortality was 6.3%. Mean difference (ABG-VBG) and LOA between paired arterial and venous measurements were 0.036 (LOA -0.048 to 0.120) for pH, -1.27 mmol/L (LOA -4.35 to 1.81) for BD, -0.64 mmol/L (LOA -1.86 to 0.57) for lactate and -1.97 mmol/L (LOA -5.49 to 1.55) for bicarbonate. Independent assessment of the VBG 'false negative' cases (n=20) suggested an ABG would change circulatory management in two cases. CONCLUSIONS: In trauma patients VBG and ABG parameters displayed suboptimal agreement. However, in cases flagged as VBG 'false negative' independent review indicated that the availability of an ABG was unlikely to change management.

Randomised controlled trial of simulation-based education for mechanical cardiopulmonary resuscitation training.

INTRODUCTION: Mechanical cardiopulmonary resuscitation (M-CPR) is increasingly used in the management of cardiac arrest. There are no previously reported randomised studies investigating M-CPR training. This study of newly trained M-CPR providers hypothesised that a brief simulation-based intervention after 4 months would improve M-CPR performance at 6 months. METHODS: This study used a simulated 'in situ' cardiac arrest model. The M-CPR device used was a proprietary Lund University Cardiac Assist System 3 machine (Physio Control, Redmond, Washington, USA). Standardised baseline training was provided to all participants. Following training, baseline performance was assessed. The primary outcome measure was the time taken to initiate M-CPR and the secondary outcome was performance against a checklist of errors. Participants were then randomised to intervention group (simulation training) or control group (routine clinical use of M-CPR). After 6 months the outcome measures were reassessed. Comparative statistical tests used an intention-to-treat analysis. RESULTS: 112 participants were enrolled. The intervention group (n=60) and control group (n=52) had similar demographic characteristics. At the 6-month assessment, median time to M-CPR initiation was 27.0 s (IQR 22.0-31.0) in the intervention group and 31.0 s (IQR 25.6-46.0) in the control group (p=0.003). The intervention group demonstrated fewer errors compared with controls at 6 months (p<0.001) CONCLUSION: In this randomised study of approaches to M-CPR training, providers receiving additional simulation-based training had higher retention levels of M-CPR skills. Therefore, when resuscitation skills are newly learnt, provision follow-up training should be an important consideration.

Management of critical illness with non-invasive ventilation by an Australian HEMS.

BACKGROUND: Non-invasive ventilation (NIV) therapy is widely used for the management of acute respiratory failure. The objective of this study was to investigate the current use of NIV during interhospital retrievals in an Australian physician-led aeromedical service. METHODS: We reviewed patients receiving NIV during interhospital retrieval at the Greater Sydney Area Helicopter Medical Services (GSA-HEMS) over a 14-month period. The main objectives were to describe the number of retrievals using NIV, the need for intubation in NIV patients and the effect of the therapy on mission duration. RESULTS: Over the study period, 3018 missions were reported; 106 cases (3.51%) involved administration of NIV therapy during the retrieval. The most common indication for NIV was pneumonia (34.0%). 86/106 patients received a successful trial of NIV therapy prior to interhospital transfer. 58 patients were transferred on NIV, while 28 patients had NIV removed during transport. None of these 86 patients required intubation or died, although 17/86 ultimately required intubation within 24 hours at the receiving centre. 20/106 patients required intubation at the referring hospital after a failed trial of NIV therapy. NIV was successfully used in all available transport platforms including rotary wing. Patients receiving NIV were found to have prolonged mission durations compared with other GSA-HEMS patients (222.5 vs 193 min). This increase in mission duration was largely attributable to NIV failure, resulting in a need for Rapid Sequence Intubation at the referring hospital. CONCLUSIONS: With careful patient selection, the use of interhospital NIV is feasible and appears to be safe in a retrieval system with care provided by a critical care physician.

The Australasian Resuscitation In Sepsis Evaluation: Fluids or vasopressors in emergency department sepsis (ARISE FLUIDS), a multi-centre observational study describing current practice in Australia and New Zealand.

OBJECTIVES: To describe haemodynamic resuscitation practices in ED patients with suspected sepsis and hypotension. METHODS: This was a prospective, multicentre, observational study conducted in 70 hospitals in Australia and New Zealand between September 2018 and January 2019. Consecutive adults presenting to the ED during a 30-day period at each site, with suspected sepsis and hypotension (systolic blood pressure <100 mmHg) despite at least 1000 mL fluid resuscitation, were eligible. Data included baseline demographics, clinical and laboratory variables and intravenous fluid volume administered, vasopressor administration at baseline and 6- and 24-h post-enrolment, time to antimicrobial administration, intensive care admission, organ support and in-hospital mortality. RESULTS: A total of 4477 patients were screened and 591 were included with a mean (standard deviation) age of 62 (19) years, Acute Physiology and Chronic Health Evaluation II score 15.2 (6.6) and a median (interquartile range) systolic blood pressure of 94 mmHg (87-100). Median time to first intravenous antimicrobials was 77 min (42-148). A vasopressor infusion was commenced within 24 h in 177 (30.2%) patients, with noradrenaline the most frequently used (n = 138, 78%). A median of 2000 mL (1500-3000) of intravenous fluids was administered prior to commencing vasopressors. The total volume of fluid administered from pre-enrolment to 24 h was 4200 mL (3000-5661), with a range from 1000 to 12 200 mL. Two hundred and eighteen patients (37.1%) were admitted to an intensive care unit. Overall in-hospital mortality was 6.2% (95% confidence interval 4.4-8.5%). CONCLUSION: Current resuscitation practice in patients with sepsis and hypotension varies widely and occupies the spectrum between a restricted volume/earlier vasopressor and liberal fluid/later vasopressor strategy.

The Australasian Resuscitation In Sepsis Evaluation: FLUid or vasopressors In Emergency Department Sepsis, a multicentre observational study (ARISE FLUIDS observational study): Rationale, methods and analysis plan.

OBJECTIVE: There is uncertainty about the optimal i.v. fluid volume and timing of vasopressor commencement in the resuscitation of patients with sepsis and hypotension. We aim to study current resuscitation practices in EDs in Australia and New Zealand (the Australasian Resuscitation In Sepsis Evaluation: FLUid or vasopressors In Emergency Department Sepsis [ARISE FLUIDS] observational study). METHODS: ARISE FLUIDS is a prospective, multicentre observational study in 71 hospitals in Australia and New Zealand. It will include adult patients presenting to the ED during a 30 day period with suspected sepsis and hypotension (systolic blood pressure <100 mmHg) despite at least 1000 mL fluid resuscitation. We will obtain data on baseline demographics, clinical and laboratory variables, all i.v. fluid given in the first 24 h, vasopressor use, time to antimicrobial administration, admission to intensive care, organ failure and in-hospital mortality. We will specifically describe (i) the volume of fluid administered at the following time points: when meeting eligibility criteria, in the first 6 h, at 24 h and prior to vasopressor commencement and (ii) the frequency and timing of vasopressor use in the first 6 h and at 24 h. Screening logs will provide reliable estimates of the proportion of ED patients meeting eligibility criteria for a subsequent randomised controlled trial. DISCUSSION: This multicentre, observational study will provide insight into current haemodynamic resuscitation practices in patients with sepsis and hypotension as well as estimates of practice variation and patient outcomes. The results will inform the design and feasibility of a multicentre phase III trial of early haemodynamic resuscitation in patients presenting to ED with sepsis and hypotension.