key: cord-0989521-8uwtwsug
authors: Settembre, Nicla; Maurice, Pauline; Paysant, Jean; Theurel, Jean; Claudon, Laurent; Hani, Hind; Chenuel, Bruno; Ivaldi, Serena
title: The use of exoskeletons to help with prone positioning in the intensive care unit during COVID-19
date: 2020-06-10
journal: Ann Phys Rehabil Med
DOI: 10.1016/j.rehab.2020.05.004
sha: f09bcd162546c6332978cda0fa350f4074d8ec67
doc_id: 989521
cord_uid: 8uwtwsug

nan

J o u r n a l P r e -p r o o f patients with severe COVID-19-related acute respiratory distress syndrome (ARDS) and requiring prone positioning (PP).

The PP procedure is of crucial importance for severe ARDS patients (1) , especially when related to COVID-19 (2) . Although turning a patient into the prone position is not an invasive procedure, it is complex and has many potential adverse effects requiring adequate and well-trained staff. It is also an exhausting and time-consuming task for ICU staff under stressful conditions. Therefore, at the University Hospital of Nancy, dedicated medical teams helped intensivist physicians strictly follow PP guidelines, thereby ensuring the full medical care for critical ARDS patients. Each PP team (PPT) consisted of 1 non-intensivist senior physician, 2 residents, and 2 medical students. Volunteers were trained in a simple ad-hoc training session consisting of 3 to 6 real PP procedures supervised by permanent physicians and nurses of the ICU.

PPTs were deployed from March 23 to April 24, 2020, in an extended ICU (from 22 to 46 beds). During this period, they performed a mean [SD] of 11.5 [3.4] placements per day, with up to 23 placements (PP or its opposite, supine positioning [SP]) at the surge of the outbreak on April 3. Overall, more than 350 placements were performed during this month, corresponding to a total manipulated weight > 30 tons. The PP task is not only physically difficult but also a risk factor for back injuries due to recurrent forward-bending postures.

To deal with this repetitive and depleting task, we investigated whether the use of back-support exoskeletons was helpful and feasible in the context of an ICU facing the CODIV-19 pandemic.

Our pilot study consisted of two steps: first, an exploratory study with whole-body kinematics assessment and evaluation of potential exoskeletons, carried out under simulated conditions, then implementation in a real-life situation with the selected exoskeletons. The exploratory study was carried out at the Hospital Simulation Center of the University of Lorraine.

We recorded the whole-body kinematics of one experienced PPT volunteer (male, 35 years old, 175 cm) by using the Xsens inertial motion capture system. Postural analysis of the PP maneuver without After testing each exoskeleton, these 2 participants completed a technology acceptance questionnaire adapted from (4) to evaluate the perceived effort, safety, comfort, efficacy, installation, and intention to use. Each construct of the questionnaire regroups several items on a 5-point Likert scale, with 1 indicating "strongly negative" and 5 "strongly positive"; 3 is the neutral answer. The reported scores are described according to the mean [SD] of all questions related to each construct (safety, comfort, usability, etc.). The participants also reported on their experience in a semi-directed interview.

Both participants perceived a reduction in physical effort when using all exoskeletons except CORFOR Both participants reported that CrayX was too cumbersome to wear in an ICU, whereas the mechanical design of BackX unpleasantly hindered several arm movements of the PP maneuver. CORFOR was not helpful. Conversely, participants were satisfied with Laevo in terms of perceived assistance during bent postures, ease of use, and freedom of movement. Importantly, they mentioned that Laevo did not modify their movements during the PP maneuver, which was confirmed by the analysis of the kinematic data (Fig. 2) .

Building upon these promising pilot results and given the urgency associated with the COVID-19 crisis, we proceeded to test under real-life conditions to demonstrate the feasibility of using Laevo in a COVID-19 ICU situation. The same 2 volunteers were each equipped with a Laevo in a way that complies with the drastic hygiene rules of the ICU during the outbreak. During a typical 3-hr shift, they Cardiac activity of the 2 participants was monitored with a Holter-ECG during the whole shift in the ICU. Unfortunately, the analysis of the ECG data was inconclusive because of the multiple bias in this J o u r n a l P r e -p r o o f real-life condition, such as the elevated stress of the participants due to the COVID-19 context and the frequency of multiple gestures performed during the PP maneuver preventing the precise characterization of the help of exoskeleton in terms of heart rate data. Although we could not reliably measure the physiological and biomechanical effects of Laevo in the ICU, we expect beneficial effects such as those reported by previous laboratory studies with similar postures (5,6).

The participants found Laevo comfortable (questionnaire score: 4.5 [0.5]), except when walking, which is a well-known issue of Laevo v1 (7) that was improved in recent versions. Laevo did not prevent or constrain the usual gestures and activity in the ICU. Accordingly, their teammates did not notice any particular changes in the practice, and no physical or psychological side effects were observed. These results are important for a potential adoption of Laevo by the PPT in current practice because the positive attitude of co-workers is fundamental for the acceptance of a new technology at work (8) .

The use of exoskeletons to cope with an exhausting task such as prone positioning in the ICU to safely maintain a large number of patients on mechanical ventilation during the surge of the COVID-19 outbreak is a consistent topic of research. Our pilot study showed that using an exoskeleton to assist medical staff could be helpful and be readily feasible, even in the dreadful context of the COVID-19 pandemic.

Previous studies generally agree on the efficiency of passive back-support exoskeletons to reduce lumbar muscular activity and perceived exertion/discomfort, particularly during operations involving trunk flexion/extension in the sagittal plane (9,10). However, although occupational exoskeletons are deployed in the industrial sector (11) , their use in the healthcare system is rarely reported, with no reported use in ICUs.

The medical staff using the passive exoskeleton Laevo during the PP maneuvers in the ICU perceived physical relief in the low back during bent postures, particularly when working at the patient's head.

Subjective evaluation, which is used in field studies to evaluate the adoption of exoskeletons in 

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