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An Isolation Device to Contain Aerosol During Aerosol Generating Procedures in the Operating Room

A Randomized Controlled Trial to Test a Novel Negative Pressure Isolation Device During Aerosol Generating Procedures in the Operating Room

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04864236
Enrollment
79
Registered
2021-04-28
Start date
2021-06-29
Completion date
2021-09-01
Last updated
2022-10-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Aerosol Containment, Aerosol Generating Procedure

Keywords

health care worker exposure

Brief summary

The purpose of this study is to test the safety and efficacy of a new isolation device to contain aerosol during aerosol-generating procedures in the operating room.

Detailed description

Patients with SARS-CoV-2 infections may require procedures that generate infectious aerosols (suspension of tiny particles or droplets in the air). Aerosols are believed to be the primary method of spread of SARS-CoV-2, as well as many other communicable diseases. In the health care setting, the providers who are in close proximity to patients during these aerosol-generating procedures (ie. Intubation (tube in your throat to help you breathe), noninvasive positive pressure ventilation (breathing support administered through a face or nasal mask) methods such as continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP), bronchoscopy (thin tube through nose or mouth into the lungs), high flow nasal cannula (oxygen delivery through the nose at a very high flow rate)) are at risk for becoming infected with SARS-CoV-2. The current standard of care to prevent the spread of virus to health care workers involves the use of N-95 respirators (particulate filtering facepiece respirators), which have been intermittently in short supply throughout the current COVID-19 pandemic. In addition, even when there are adequate supplies of N-95 respirators, health care workers have been reusing the respirators multiple times, which may result in decreased efficacy and potential viral exposure. In order to provide enhanced protection to health care workers during aerosol-generating procedures, the study investigators have created a device, named SLACC (Suction-assisted Local Aerosol Containment Chamber). SLACC has the ability to isolate the atmosphere around the patient's upper airway (nose, mouth, throat) via negative pressure in a manner analogous to isolation rooms used to house patients with communicable diseases spread by aerosol (e.g. tuberculosis). Furthermore, SLACC is inexpensive, portable, and relatively simple to manufacture. The SLACC uses an external suction source to maintain a negative pressure micro-atmosphere around a patient's head (the source of infectious aerosols). The components of SLACC include a clear polymer frame, a flexible drape, and integrated sealed arm sleeves to protect the hands and forearms of the health care provider. The structure is flexible during use, transparent, can be rapidly assembled, and easily collapsible for removal and transport. It is assembled using adhesive-backed polymer sections, allowing the structure to fold from a flat shipping/storage conformation into a free-standing structure. Once deployed with the patient's head inside the chamber, the drape is secured across the open side of the chamber with adhesive and covers the patient's torso. Many other containment devices have been proposed during the COVID-19 pandemic, but none have been demonstrated to contain aerosols effectively. With external suction applied, the investigators believe SLACC vastly improves upon the aerosol containment ability of other devices. The investigators have tested SLACC in a simulated setting and recently published the results in a high-quality, peer-reviewed journal (PMID: 32541251). The investigators propose to test the safety and efficacy of SLACC in containing contamination during aerosol-generating procedures in the operating room through a randomized controlled trial. The investigators have identified a method of objectively quantifying health care worker exposure to respiratory particles and plan to compare exposure to the number and size of respiratory particles when SLACC is used compared to the current standard of care (no device used).

Interventions

DEVICENovel isolation device to contain aerosol

The novel isolation device is called SLACC (Suction-assisted Local Aerosol Containment Chamber). SLACC has the ability to isolate the atmosphere around the patient's upper airway (nose, mouth, throat) via negative pressure in a manner analogous to isolation rooms used to house patients with communicable diseases spread by aerosol (e.g. tuberculosis). The SLACC uses an external suction source to maintain a negative pressure micro-atmosphere around a patient's head (the source of infectious aerosols). The components of SLACC include a clear polymer frame, a flexible drape, and integrated sealed arm sleeves to protect the hands and forearms of the health care provider. The structure is flexible during use, transparent, can be rapidly assembled, and easily collapsible for removal and transport. Once deployed with the patient's head inside the chamber, the drape is secured across the open side of the chamber with adhesive and covers the patient's torso.

Sponsors

John Shin
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Elective scheduled surgery (not emergent) * Planned general anesthesia requiring intubation

Exclusion criteria

* Patients refusing or unable to consent for any reason, including claustrophobia or inability to cooperate * Patients predicted to require the use of fiberoptic bronchoscopy for intubation

Design outcomes

Primary

MeasureTime frameDescription
Particle Count Measurements During Intubationparticle counts will be measured continuously from the time of patient's entry into the operating room until the patient has been intubated for surgery, approximately 15 minutes totalparticle counts will be measured using a commercially-available particle counter at two locations: at the level of the anesthesiology provider's face (at the patient's head), and at the level of the assistant provider's face (at the patient's side)

Secondary

MeasureTime frameDescription
Time to Intubationduring intubationdefined as time from the first entry of laryngoscope into pt's oropharynx to the time of confirmed successful tracheal intubation
Total Number of Intubation Attemptsduring intubationtotal number of intubation attempts during airway management
Pre-operative Airway Assessment (Mallampati Score)pre-operative assessmentMallampati score, can be given a score of 1-4 (whole numbers only), score of 4 indicates higher likelihood of difficult intubation and score of 1 indicates lower likelihood of difficult intubation
Laryngoscopy Grade View (Cormack-Lehane) Obtained During Intubationduring intubationCormack-Lehane grade assigned by anesthesiologist during intubation, grade can be 1-4, grade 1 correlates with a view of entirety of vocal cords while grade 4 correlates with no view at all of any part of the vocal cords
Pre-operative Airway Assessment (Thyromental Distance)pre-operative assessmentthyromental distance is the distance measured between the chin and the thyroid cartilage (both landmarks are readily palpable on physical exam), this distance is typically measured in centimeters or as a measure of the number of finger breadths (as reported here). Finger breadths is defined as the number of finger widths that can fit within the defined distance.

Countries

United States

Participant flow

Participants by arm

ArmCount
Intervention Group
This group will undergo airway management in the operating room as part of the anesthesia for surgery in the presence of the novel isolation device. Novel isolation device to contain aerosol: The novel isolation device is called SLACC (Suction-assisted Local Aerosol Containment Chamber). SLACC has the ability to isolate the atmosphere around the patient's upper airway (nose, mouth, throat) via negative pressure in a manner analogous to isolation rooms used to house patients with communicable diseases spread by aerosol (e.g. tuberculosis). The SLACC uses an external suction source to maintain a negative pressure micro-atmosphere around a patient's head (the source of infectious aerosols). The components of SLACC include a clear polymer frame, a flexible drape, and integrated sealed arm sleeves to protect the hands and forearms of the health care provider. The structure is flexible during use, transparent, can be rapidly assembled, and easily collapsible for removal and transport. Once deployed with the patient's head inside the chamber, the drape is secured across the open side of the chamber with adhesive and covers the patient's torso.
39
Control Group
This group will undergo airway management in the operating room in an identical manner to the intervention group except that the SLACC device will not be used.
40
Total79

Baseline characteristics

CharacteristicControl GroupTotalIntervention Group
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
18 Participants26 Participants8 Participants
Age, Categorical
Between 18 and 65 years
22 Participants53 Participants31 Participants
Age, Continuous54.1 years
STANDARD_DEVIATION 19.3
52.9 years
STANDARD_DEVIATION 17.7
51.7 years
STANDARD_DEVIATION 16
Race and Ethnicity Not Collected0 Participants
Region of Enrollment
United States
40 participants79 participants39 participants
Sex: Female, Male
Female
20 Participants43 Participants23 Participants
Sex: Female, Male
Male
20 Participants36 Participants16 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 390 / 40
other
Total, other adverse events
0 / 390 / 40
serious
Total, serious adverse events
0 / 390 / 40

Outcome results

Primary

Particle Count Measurements During Intubation

particle counts will be measured using a commercially-available particle counter at two locations: at the level of the anesthesiology provider's face (at the patient's head), and at the level of the assistant provider's face (at the patient's side)

Time frame: particle counts will be measured continuously from the time of patient's entry into the operating room until the patient has been intubated for surgery, approximately 15 minutes total

ArmMeasureGroupValue (MEDIAN)
Intervention GroupParticle Count Measurements During IntubationDeep breathing/coughing phase, patient location4026 particles/cm^3
Intervention GroupParticle Count Measurements During IntubationDeep breathing/coughing phase, physician location105 particles/cm^3
Intervention GroupParticle Count Measurements During IntubationDeep breathing/coughing phase, assistant location74 particles/cm^3
Intervention GroupParticle Count Measurements During IntubationIntubation phase, patient location1560 particles/cm^3
Intervention GroupParticle Count Measurements During IntubationIntubation phase, physician location48 particles/cm^3
Intervention GroupParticle Count Measurements During IntubationIntubation phase, assistant location27 particles/cm^3
Control GroupParticle Count Measurements During IntubationIntubation phase, physician location556 particles/cm^3
Control GroupParticle Count Measurements During IntubationDeep breathing/coughing phase, patient location411 particles/cm^3
Control GroupParticle Count Measurements During IntubationIntubation phase, patient location490 particles/cm^3
Control GroupParticle Count Measurements During IntubationDeep breathing/coughing phase, physician location392 particles/cm^3
Control GroupParticle Count Measurements During IntubationIntubation phase, assistant location218 particles/cm^3
Control GroupParticle Count Measurements During IntubationDeep breathing/coughing phase, assistant location185 particles/cm^3
p-value: <0.001Wilcoxon (Mann-Whitney)
Secondary

Laryngoscopy Grade View (Cormack-Lehane) Obtained During Intubation

Cormack-Lehane grade assigned by anesthesiologist during intubation, grade can be 1-4, grade 1 correlates with a view of entirety of vocal cords while grade 4 correlates with no view at all of any part of the vocal cords

Time frame: during intubation

ArmMeasureValue (MEAN)Dispersion
Intervention GroupLaryngoscopy Grade View (Cormack-Lehane) Obtained During Intubation1.21 score on a scaleStandard Deviation 0.41
Control GroupLaryngoscopy Grade View (Cormack-Lehane) Obtained During Intubation1.10 score on a scaleStandard Deviation 0.3
p-value: 0.198t-test, 1 sided
Secondary

Pre-operative Airway Assessment (Mallampati Score)

Mallampati score, can be given a score of 1-4 (whole numbers only), score of 4 indicates higher likelihood of difficult intubation and score of 1 indicates lower likelihood of difficult intubation

Time frame: pre-operative assessment

ArmMeasureValue (MEAN)Dispersion
Intervention GroupPre-operative Airway Assessment (Mallampati Score)1.74 score on a scaleStandard Deviation 0.68
Control GroupPre-operative Airway Assessment (Mallampati Score)1.53 score on a scaleStandard Deviation 0.72
p-value: 0.167t-test, 1 sided
Secondary

Pre-operative Airway Assessment (Thyromental Distance)

thyromental distance is the distance measured between the chin and the thyroid cartilage (both landmarks are readily palpable on physical exam), this distance is typically measured in centimeters or as a measure of the number of finger breadths (as reported here). Finger breadths is defined as the number of finger widths that can fit within the defined distance.

Time frame: pre-operative assessment

ArmMeasureValue (MEAN)Dispersion
Intervention GroupPre-operative Airway Assessment (Thyromental Distance)3.10 finger breadthsStandard Deviation 0.38
Control GroupPre-operative Airway Assessment (Thyromental Distance)3.18 finger breadthsStandard Deviation 0.45
p-value: 0.442t-test, 1 sided
Secondary

Time to Intubation

defined as time from the first entry of laryngoscope into pt's oropharynx to the time of confirmed successful tracheal intubation

Time frame: during intubation

ArmMeasureValue (MEAN)Dispersion
Intervention GroupTime to Intubation51.6 secondsStandard Deviation 22.2
Control GroupTime to Intubation41.8 secondsStandard Deviation 25.7
p-value: 0.073t-test, 1 sided
Secondary

Total Number of Intubation Attempts

total number of intubation attempts during airway management

Time frame: during intubation

ArmMeasureValue (MEAN)Dispersion
Intervention GroupTotal Number of Intubation Attempts1.05 number of attemptsStandard Deviation 0.22
Control GroupTotal Number of Intubation Attempts1.08 number of attemptsStandard Deviation 0.27
p-value: 0.67t-test, 1 sided

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026