key: cord-0860438-tauf23ql
authors: McGain, Forbes; Bates, Samantha; Lee, Jung Hoon; Timms, Patrick; Kainer, Marion A.; French, Craig; Monty, Jason
title: A Prospective Clinical Evaluation of a Patient Isolation Hood During the COVID-19 Pandemic
date: 2021-05-11
journal: Aust Crit Care
DOI: 10.1016/j.aucc.2021.05.001
sha: c225a2938c2887daa9eacf078e532aa8b266a93a
doc_id: 860438
cord_uid: tauf23ql

BACKGROUND: Healthcare workers have frequently become infected with SARS-CoV-2 whilst treating patients with COVID-19. A variety of novel devices have been proposed to reduce COVID-19 cross contamination. OBJECTIVE: (i) To test whether patients and Healthcare workers (HCWs) thought that a novel patient isolation hood was safe and comfortable, and (ii) to obtain hospital HCW COVID-19 infections. METHODS: Prospective cohort study of 20 patients, entailing HCWSS/patient questionnaires, and safety aspects of prototype isolation hoods. Prospective collection of HCW COVID-19 data. Assessment of the hood’s safety and practicality, and adverse event reporting. OUTCOME MEASURES: Questionnaires’ responses, adverse events reporting, rates of HCW infections during study period (20/6/2020 - 21/7/2020). HCW COVID-19 infections reported until last recorded HCW COVID-19 diagnosis (20/6/2020 - 27/9/2020). RESULTS: Of the 60/64 eligible individual HCW surveys, all 60 surveys were overall favourable (>75% questions answered in favour of the isolation hood). HCWs were unanimous in: perceiving the hood as safe (60/60), preferring its use (56/56), and understanding its potential COVID-19 cross-contamination minimisation (60/60). All eight patients who completed the questionnaire thought the isolation hood helped prevent COVID-19 cross-infection, was safe, and comfortable. There were no reported patient safety adverse events. The COVID-19 attack rate from 20/6/2020-27/9/2020 among registered nurses was: ICUs 2.2% (3/138), Geriatric wards 13.2% (26/197), and COVID-19 Wards 18.3% (32/175). The COVID-19 attack rate among medical staff was: junior staff 2.1% (24/932), senior staff 0.7% (4/607), aged care/rehabilitation 6.7% (2/30), and ICU all medical staff 8.6% (3/35). CONCLUSIONS: The isolation hood was preferred to standard care by HCWs, and well tolerated by patients, and post-study became part of standard ICU therapy. There was an association between being an ICU nurse and a low COVID-19 infection rate (no causality implied). ICU HCWs feel safer when treating patients with COVID-19 using an isolation hood.

pandemic. 2 The World Health Organization indicates that approximately 14% of people with COVID-19 require hospitalization (with O 2 support), and 5% require intensive care unit (ICU) admission. 2 Controversy surrounds the degree to which SARS-CoV-2 virus is spread via more localized droplets versus more distantly spread aerosols. 3, 4 There is ongoing concern about SARS-CoV-2 infectious spread to healthcare workers (HCWs), and particularly from aerosol generating procedures (AGPs) such as intubation/extubation, nebuliser therapies, high flow O 2 , and non-invasive ventilation. 5, 6 During the COVID-19 Pandemic the prevention of HCW cross infections has largely focussed on personal protective equipment (PPE). 7 Controlling ventilation to avoid source spread from infected patients with respiratory diseases is arguably at least as important as appropriate PPE. 8 Negative Pressure isolation Rooms (Class N= NPRs) can provide greater ventilation control than open-plan rooms but are a limited resource. 9 Hospital NPRs provide high flows (12 air changes/hour) and negative pressure to prevent the spread of pathogens beyond the room's confines, 9 however infectious spread to personnel within the room remains problematic. Personal ventilation devices to protect HCWs and other patients from respiratory infections have been explored during prior and current infectious diseases outbreaks, such as SARS (2003), 1 and COVID-19. 10, 11 Such personal ventilation devices could be particularly useful for settings when the patient is in an open ICU or other healthcare settings.

We conducted a prospective cohort study to evaluate the safety and comfort of prototype personal ventilation hoods (the McMonty isolation hood, see Figure 1 , https://medihood.com.au/) in a clinical setting. We also prospectively observed the number of HCWs COVID-19 infections in the ICU and other areas of the health service. In particular, we prospectively obtained HCW COVID-19 infections in hospital areas that treated large numbers of patients with COVID-19 (the ICU and ED, COVID designated wards, and Geriatric wards). The isolation hoods were used only in the ICU and ED; we sought any potential association between use of the isolation hoods in the ED/ICU versus other hospital wards, and HCWs' COVID-19 infection rates.

J o u r n a l P r e -p r o o f 

We undertook a prospective, interventional study of 20 patients whose management included the use of a personal isolation hood. This hospital ethics approved study for a Therapeutic Goods Administration (TGA) listed isolation hood device was conducted from 20/6/2020-21/7/2020 in the two general Intensive care units (ICUs) and Emergency Departments (EDs) at a metropolitan healthcare service in Melbourne, Australia. Feedback from participants and HCWs was obtained via a structured questionnaire. Two independent data safety monitors provided stewardship of trial conduct and adverse event reporting. Further details about the personal isolation McMonty Hood 12 and the TGA adapted 13 Participants were free to open the hood cover or discontinue in the trial at any time. HCWs could also cease use of the hood at any time. Use of the hood ceased when a patient had: (i) been declared negative for COVID-19 or another respiratory infectious disease, (ii) completed at least 7 days of treatment and deemed clinically appropriate by HCWs to cease use, (iii) been discharged from the ICU or hospital, or (iv) withdrew from the study.

The We deemed that each questionnaire required a minimum of 50% of questions to be answered for data inclusion. Questions with a Yes/No answer were deemed 1/0 points for positive and negative responses respectively. Questions with a scaled 1-10 answer had a value of 0 (negative response) for a value of 1-5, or 1 (positive response) for a value of 6-10. Questionnaires were deemed either overall favourable (50% or greater positively answered) or unfavourable (less than 50% positively answered).

A 75% or greater favourable response rate across all patient and HCW questionnaires was deemed favourable isolation hood endorsement. Questions with more than one answer or no answer provided were excluded. The questionnaire included a question for HCWs about the proportion of time that the isolation hood was being actively, and thus effectively used (hood down, fan on). Such was considered important as if the hood was used for a small proportion of the day it could indicate difficulty of use, poor patient/HCW tolerance, etc.

Treatment for COVID-19 hospital patients occurred in the ED, ICU, and designated COVID-19

Wards. We obtained prospective data of the observed rates of ICU HCW compared with other hospital HCW COVID-19 infections (all de-identified). We calculated the proportion of registered J o u r n a l P r e -p r o o f nurses and medical HCWSS who developed COVID-19 both for ICU HCWs, and other hospital HCWs working elsewhere within the health service. We did not distinguish between SARS-CoV-2 infections at work/home/elsewhere; only COVID-19 positivity. We considered that HCWs could become symptomatic or test positive for COVID-19 up to 14 days post-study involvement. HCWs' data are reported from the 20/6/2020 -27/9/2020 (date of last COVID-19 diagnosis at our institution).

Twelve patients with confirmed, and eight patients with suspected COVID-19 were enrolled from 20/6/2020-21/7/2020 ( Figure 2 ). Nineteen patients were treated in the ICU and one in ED (only).

J o u r n a l P r e -p r o o f Assessed for eligibility of isolation hood beyond initial cohort (n=103), i.e. numbers in addition to 20 patient trial

Enrolled (n=20)

Excluded (n=40)  Behaviour of concern, delirium or other reason (n=6 COVID-19, n=34 SCOVID-19)  Patient refused (n=0)

 COVID-19 +ve patients (n=34)  Suspected COVID-19 (eventual negative swab returned) (n=29) J o u r n a l P r e -p r o o f Of the twenty patients who received the isolation hoods, eleven patients received invasive ventilation, five received non-invasive ventilation and two received nebuliser therapy (Table 1) . 3 (1-29) ICU length of stay in days for those intubated during their ICU stay (median (range)) 13 (1-29) Length of isolation hood use in days (median (range)) 3 (1-29) Hospital length of stay in days (median (range)) 5 (1-45)

The isolation hoods continued to be used beyond this study (i.e. after all questionnaires were completed on the 21/7/2020). After the 20-patient trial, 103 patients were screened for use of the isolation hood (40 excluded, all due to behaviour of concern, and delirium). A total of 34 COVID-19

patients and 29 suspected COVID-19 patients received the isolation hoods post-study, i.e. from the 22/7/2020 to 27/9/2020 (last date a HCWSS at our institution was diagnosed with COVID-19).

Of the 64 individual HCWs' surveys, 60 (94%) were eligible (>=50% of questions answered), and all 60 surveys were overall favourable (>75% questions answered in favour of the isolation hood); see Negative patient comments about the hood were: noise: "Just have to get staff to speak up, I just spoke up a little more, and it was ok", and "I had to yell and try to open the hood, which I couldn't do easily", lighting: "The overhead lights bounced off the plastic a little bit, depending on the angle of the plastic, but not troublesome", and temperature: "I felt a bit trapped and too hot."

Positive patient comments about the hood were: "I liked how I can still see activity happening around me", "Normally I have to go in an isolation room when I come to hospital and it's very lonely. You can see nobody for hours.", "This hood lets me still be seen by staff and I don't feel forgotten about."

and, "I felt that it helped to stop the spread of infectious diseases."

No patient related safety adverse events were reported. All adverse events were technical concerns related to the isolation hood's design or operation. The data safety monitors received two near incidents and nine non-incidents. Additional details of the non-incidents and rectification required are presented in Supplementary Appendix 4. The final non-incident involved an audible alarm that confirmed the fan was on (an additional feature to remind HCWs the fan should be on while the hood was down). The alarm remained on continuously, necessitating its removal. New prototypes were fitted with a light at front of the hood to indicate that fan was on.

All HCWs' COVID-19 infection data are from 20/6/2020 until 27/9/2020. The overall attack COVID- Our study has limitations. By its nature it was unblinded, and the single health centre sample size was small. We did not distinguish between nurse/doctor/other questionnaire responses, or conduct detailed investigation of infection control procedures. Further bias may have arisen due to ICU HCW and ICU researcher familiarity. We did not measure viral loads within/exterior to the isolation hoods. We had no ability to adjust for potential confounders. While the observed attack rate for ICU registered nurses was low it remains uncertain if the isolation hood reduces HCWs' COVID-19 infections: no causal inference may be drawn.

This study complements our pre-clinical assessment of the isolation hood's efficacy of limiting aerosol spread. 12 The results of this study support the conduct of translational research and implementation studies of the isolation hood in other hospital areas and other jurisdictions. This study provides evidence of the safety and comfort of an isolation hood as part of routine treatment of patients with COVID-19. There was a high rate of acceptance by patients and HCWs, and the potential that family visits to the ICU/ward could be made more frequently. It is apparent that HCWs feel safer when treating patients using a personal ventilation hood. It is plausible the isolation hood reduces HCW COVID-19 infections. Additional studies to define the role of this device are indicated.

J o u r n a l P r e -p r o o f

A novel coronavirus from patients with pneumonia in China

Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: interim guidance

Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of COVID-19

Controversy around airborne versus droplet transmission of respiratory viruses: implication for infection prevention

Australian and New Zealand Intensive Care Society. ANZICS Covid-19 Guidelines. Version 2

Airborne or droplet precautions for health workers treating COVID-19?

Using Personal Protective Equipment (PPE) 2020

Airborne transmission of SARS-CoV-2: the world should face the reality

State Government of Victoria DoHaHS. Design Guidelines for Hospitals and Day Procedures

NIOSH Ventilated Headboard Provides Solution to Patient Isolation During an Epidemic

Covid19: minimising risk to healthcare workers during aerosol producing respiratory therapy using an innovative constant flow canopy

Aerosol generation related to respiratory interventions and the effectiveness of a personal ventilation hood

Therapeutic Goods Administration. Reporting adverse events

Control of airborne infectious diseases in ventilated spaces

Victorian healthcare worker coronavirus (COVID-19) data. 2020

We thank the Western Health (WH) ICU research team: Rebecca McEldrew, Miriam Towns, and Rebecca Morgan for data collection, WH ICU and ED staff. We also thank the assistance of WH Research Manager Bill Karanatsios for TGA submission and notification etc. We thank the WH Infection Prevention team led by Richard Bartolo for input to the care and cleaning of the isolation hoods, patient consumer representatives John Ward and Grant Carroll for input on questionnaires. Assistance from the University of Melbourne Department of Mechanical Engineering (Kevin Kevin, Max Rounds, Geoff Duke) in the isolation hood prototype developments and improvements was integral. We thank Professors Michael Reade, and Rey Chin for their role as Data Safety Monitors for this clinical trial. We also thank the University of Melbourne and The Western Health Foundation for funding to construct the first 17 isolation hoods as used in this clinical trial.