Critical COVID-19 patient evacuation on an amphibious assault ship: feasibility and safety. A case series

Collective aeromedical evacuations of SARS-CoV-2-related ARDS patients in a military tactical plane: a retrospective descriptive study

After the appearance of the COVID-19 pandemic in France, MEROPE system was created to transform the military tactical ATLAS A400M aircraft into a flying intensive care unit. Collective aeromedical evacuations (aero-MEDEVAC) of patients suffering from SARS-CoV-2-related acute respiratory distress syndrome was performed from June to December 2020. A total of 22 patients were transported during seven missions. All aero-MEDEVAC was performed in safe conditions for patients and crew. No life-threatening conditions occurred during flight. Biohazard controls were applied according to French guidelines and prevented crew contamination. Thanks to rigorous selection criteria and continuous in-flight medical care, the safe transportation of these patients was possible. To the best of our knowledge, this is the first description of collective aero-MEDEVAC of these kinds of patients using a tactical military aircraft. We here describe the patient's characteristics and the flight's challenges.

The Use of Portable Oxygen Concentrators in Low-Resource Settings: A Systematic Review

INTRODUCTION

Portable oxygen concentrators (POCs) are medical devices that use physical means to separate oxygen from the atmosphere to produce concentrated, medical-grade gas. Providing oxygen to low-resources environments, such as austere locations, military combat zones, rural Emergency Medical Services (EMS), and during disasters, becomes expensive and logistically intensive. Recent advances in separation technology have promoted the development of POC systems ruggedized for austere use. This review provides a comprehensive summary of the available data regarding POCs in these challenge environments.

METHODS

PubMed, Google Scholar, and the Defense Technical Information Center were searched from inception to November 2021. Articles addressing the use of POCs in low-resource settings were selected. Three authors were independently involved in the search, review, and synthesis of the articles. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines.

RESULTS

The initial search identified 349 articles, of which 40 articles were included in the review. A total of 724 study subjects were associated with the included articles. There were no Level I systematic reviews or randomized controlled trials.

DISCUSSION

Generally, POCs are a low-cost, light-weight tool that may fill gaps in austere, military, veterinary, EMS, and disaster medicine. They are cost-effective in low-resource areas, such as rural and high-altitude hospitals in developing nations, despite relatively high capital costs associated with initial equipment purchase. Implementation of POC in low-resource locations is limited primarily on access to electricity but can otherwise operate for thousands of hours without maintenance. They provide a unique advantage in combat operations as there is no risk of explosive if oxygen tanks are struck by high-velocity projectiles. Despite their deployment throughout the battlespace, there were no manuscripts identified during the review involving the efficacy of POCs for combat casualties or clinical outcomes in combat. Veterinary medicine and animal studies have provided the most robust data on the physiological effectiveness of POCs. The success of POCs during the coronavirus disease 2019 (COVID-19) pandemic highlights the potential for POCs during future mass-casualty events. There is emerging technology available that combines a larger oxygen concentrator with a compressor system capable of refilling small oxygen cylinders, which could transform the delivery of oxygen in austere environments if ruggedized and miniaturized. Future clinical research is needed to quantify the clinical efficacy of POCs in low-resource settings.

Patient outcomes following transfer between intensive care units during the COVID-19 pandemic

Transferring critically ill patients between intensive care units (ICU) is often required in the UK, particularly during the COVID-19 pandemic. However, there is a paucity of data examining clinical outcomes following transfer of patients with COVID-19 and whether this strategy affects their acute physiology or outcome. We investigated all transfers of critically ill patients with COVID-19 between three different hospital ICUs, between March 2020 and March 2021. We focused on inter-hospital ICU transfers (those patients transferred between ICUs from different hospitals) and compared this cohort with intra-hospital ICU transfers (patients moved between different ICUs within the same hospital). A total of 507 transfers were assessed, of which 137 met the inclusion criteria. Forty-five patients underwent inter-hospital transfers compared with 92 intra-hospital transfers. There was no significant change in median compliance 6 h pre-transfer, immediately post-transfer and 24 h post-transfer in patients who underwent either intra-hospital or inter-hospital transfers. For inter-hospital transfers, there was an initial drop in median PaO₂ /F_I O₂ ratio: from median (IQR [range]) 25.1 (17.8-33.7 [12.1-78.0]) kPa 6 h pre-transfer to 19.5 (14.6-28.9 [9.8-52.0]) kPa immediately post-transfer (p < 0.05). However, this had resolved at 24 h post-transfer: 25.4 (16.2-32.9 [9.4-51.9]) kPa. For intra-hospital transfers, there was no significant change in PaO₂ /F_I O₂ ratio. We also found no meaningful difference in pH; PaCO₂ ;_, base excess; bicarbonate; or norepinephrine requirements. Our data demonstrate that patients with COVID-19 undergoing mechanical ventilation of the lungs may have short-term physiological deterioration when transferred between nearby hospitals but this resolves within 24 h. This finding is relevant to the UK critical care strategy in the face of unprecedented demand during the COVID-19 pandemic.