A 3-year retrospective audit of the use of noninvasive positive pressure ventilation via the Oxylog 3000 transport ventilator during air medical retrievals

Reported adverse events during out-of-hospital mechanical ventilation and ventilatory support in emergency medical services and critical care transport crews: a systematic review

Background

Emergency medical services (EMS) and critical care transport crews constantly face critically-ill patients who need ventilatory support in scenarios where correct interventions can be the difference between life and death; furthermore, challenges like limited staff working on the patient and restricted spaces are often present. Due to these, mechanical ventilation (MV) can be a support by liberating staff from managing the airway and allowing them to focus on other areas; however, these patients face many complications that personnel must be aware of.

Aims

To establish the main complications related to out-of-hospital MV and ventilatory support through a systematic review.

Methodology

PubMed, BVS and Scopus were searched from inception to July 2021, following the PRISMA guidelines; search strategy and protocol were registered in PROSPERO. Two authors carried out an independent analysis of the articles; any disagreement was solved by mutual consensus, and data was extracted on a pre-determined spreadsheet. Only original articles were included, and risk of bias was assessed with quality assessment tools from the National Institutes of Health.

Results

The literature search yielded a total of 2,260 articles, of which 26 were included in the systematic review, with a total of 9,418 patients with out-of-hospital MV; 56.1% were male, and the age ranged from 18 to 82 years. In general terms of aetiology, 12.2% of ventilatory problems were traumatic in origin, and 64.8% were non-traumatic, with slight changes between out-of-hospital settings. Mechanical ventilation was performed 49.2% of the time in prehospital settings and 50.8% of the time in interfacility transport settings (IFTS). Invasive mechanical ventilation was used 98.8% of the time in IFTS while non-invasive ventilation was used 96.7% of the time in prehospital settings. Reporting of adverse events occurred in 9.1% of cases, of which 94.4% were critical events, mainly pneumothorax in 33.1% of cases and hypotension in 27.6% of cases, with important considerations between type of out-of-hospital setting and ventilatory mode; total mortality was 8.4%.

Conclusion

Reported adverse events of out-of-hospital mechanical ventilation vary between settings and ventilatory modes; this knowledge could aid EMS providers in promptly recognizing and resolving such clinical situations, depending on the type of scenario being faced.

Use of continuous positive airway pressure and non-invasive ventilation for respiratory failure in an Australian aeromedical retrieval service: A retrospective case series

OBJECTIVE

The purpose of the present study was to investigate the use of respiratory support via continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV) in a medical retrieval service in Queensland, Australia, with reference to transport considerations and patient safety.

METHODS

In this unblinded retrospective case series over a 13-month period, a clinical database was reviewed for the use of CPAP/NIV. Retrieval metrics as well as clinical data were recorded.

RESULTS

A total of 128 patients were transferred either by rotary (80%) or fixed wing (20%). The median transport time was 65 min. The median total mission time was 3.7 h. Fifty-two percent of patients were female. The median age was 69 years and 93% had a background of cardiorespiratory disease. Sixty-five percent of patients were receiving CPAP/NIV before arrival of the retrieval team. The main diagnoses were respiratory failure (29.7%), acute pulmonary oedema (26.6%) and chronic obstructive pulmonary disease (25.8%). There were no incidences of pneumothorax, intubation in transit, vomiting, desaturation, hypotension, cardiac arrest or death. In two cases NIV was abandoned due to mask intolerance and in one case there was a decrease in Glasgow Coma Scale by 2. In no cases was there a detrimental outcome for the patient.

CONCLUSION

The use of NIV and CPAP appears to have a low-risk profile in aeromedical retrieval even for prolonged periods of time in an adult population.

Review article: Primary aeromedical retrievals in Australia: An interrogation and search for context

Primary aeromedical retrievals are a direct scene response to patients with a critical injury or illness using a medically equipped aircraft. They are often high-acuity taskings. In Australia, information on primary retrieval taskings is housed by service providers, of which there are many across the country. This exploratory literature review aims to explore the contemporary peer-reviewed literature on primary aeromedical retrievals in Australia. The focus is on adult primary aeromedical retrievals undertaken in Australia and clinical tools used in this pre-hospital setting. Included articles were reviewed for research theme (clinical and equipment, systems and/or outcomes), data coverage and appraisal of the evidence. Of the 37 articles included, majority explored helicopter retrievals (n = 32), retrieval systems (n = 21), compared outcomes within a service (n = 10) and explored retrievals in the state of New South Wales (n = 19). Major topics of focus included retrieval of trauma patients and airway management. Overall, the publications had a lower strength of evidence because of the preponderance of cross-sectional and case-study methodology. This review provides some preliminary but piecemeal insight into primary retrievals in Australia through a localised systems lens. However, there are several areas for research action and service outcome improvements suggested, all of which would be facilitated through the creation of a national pre-hospital and retrieval registry. The creation of a registry would enable consideration of the frequency and context of retrievals, comparison across services, more sophisticated data interrogation. Most importantly, it can lead to service and pre-hospital and retrieval system strengthening.

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.

Factors Associated with Failure of Non-invasive Positive Pressure Ventilation in a Critical Care Helicopter Emergency Medical Service

INTRODUCTION

Non-invasive positive pressure ventilation (NIPPV) is used to treat severe acute respiratory distress. Prehospital NIPPV has been associated with a reduction in both in-hospital mortality and the need for invasive ventilation.

HYPOTHESIS/PROBLEM

The authors of this study examined factors associated with NIPPV failure and evaluated the impact of NIPPV on scene times in a critical care helicopter Emergency Medical Service (HEMS). Non-invasive positive pressure ventilation failure was defined as the need for airway intervention or alternative means of ventilatory support.

METHODS

A retrospective chart review of consecutive patients where NIPPV was completed in a critical care HEMS was conducted. Factors associated with NIPPV failure in univariate analyses and from published literature were included in a multivariable, logistic regression model.

RESULTS

From a total of 44 patients, NIPPV failed in 14 (32%); a Glasgow Coma Scale (GCS)<15 at HEMS arrival was associated independently with NIPPV failure (adjusted odds ratio 13.9; 95% CI, 2.4-80.3; P=.003). Mean scene times were significantly longer in patients who failed NIPPV when compared with patients in whom NIPPV was successful (95 minutes vs 51 minutes; 39.4 minutes longer; 95% CI, 16.2-62.5; P=.001).

CONCLUSION

Patients with a decreased level of consciousness were more likely to fail NIPPV. Furthermore, patients who failed NIPPV had significantly longer scene times. The benefits of NIPPV should be balanced against risks of long scene times by HEMS providers. Knowing risk factors of NIPPV failure could assist HEMS providers to make the safest decision for patients on whether to initiate NIPPV or proceed directly to endotracheal intubation prior to transport.