This update has been deprecated. Please see the revised SAGES and EAES Recommendations Regarding Surgical Response to COVID-19 Crisis for current information and recommendations.
SAGES COVID-19 / Coronavirus Announcement Archives
SAGES will compile all of its announcements and recommendations regarding Covid-19/Coronavirus at this location. Please bookmark it for your convenience.
General Disclaimer:
The following is intended to provide our members with additional information to help manage surgical patients during the COVID-19 pandemic. These are not formal guidelines and due to time constraints, SAGES has not reviewed or authenticated them by utilizing its standard rigorous guidelines process. Statements and information are updated regularly and subject to change as more data becomes available.
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Please consider joining SAGES or making a donation to the SAGES Education and Research Foundation so we can continue to bring content like this to the surgical community for free.
Basics of Mechanical Ventilation for Non-Critical Care MDs
(drafted 3/19/2020 by the SAGES Acute Care Committee)
Background:
Although the data is still very early and treatment of COVID-19 respiratory failure is still evolving, the current information suggests that the majority of critically ill COVID-19 patients are suffering only from severe hypoxia and only require management of hypoxemia using Positive End Expiration Pressure (PEEP), FiO2, and possibly prone positioning. Other underlying chronic illnesses must be treated accordingly, but again the effect of COVID-19 appears to be mostly hypoxemia. Fluid resuscitation should be minimized to maintain euvolemia and avoid hypervolemia. This primer can help provide some just in time learning for non-critical care physicians who may be called to help manage ventilators.
Working with patients with confirmed or suspected COVID-19:
When the patients are coughing or on supplemental oxygen the respiratory droplets can spread. Personal Protective Equipment (PPE) is essential for provider protection, following current CDC guidelines (link). Gowns and gloves for contact isolation and face protection will work when intubation is necessary. Care must be taken when intubating to protect the providers and the patients from harm. If the diagnosis is in question, or there is no testing available, a CT of the chest may help with the diagnosis. With COVID-19, the hypoxemia is profound, and the lung lesions are peripheral and ground glass in appearance.
Indications for mechanical ventilation:
Use of mechanical ventilation is indicated for when patients cannot maintain a patent airway (after trauma, severe altered mental status, intoxicants), have acute respiratory failure (resulting from sepsis or conditions like pancreatitis), have compromised lung function (from conditions like pneumonia or cystic fibrosis), and have difficulty breathing (weakness from frailty, pain from fracture ribs).
Settings for mechanical ventilation:
In general, the clinician can determine the following parameters for mechanical ventilation:
- Respiratory rate: normal 10-16
- Tidal Volume: amount of volume with each mechanical breath (mL per breath)
- Oxygen concentration: 20-100%
- Positive End Expiration Pressure (PEEP): amount of pressure at the end of the expiration that helps keep alveoli open for O2/CO2 exchange (typically 5-20mmHg) Most patients should have at least a PEEP of 5 to start. Obese or larger patients may need more PEEP.
- Pressure Support ventilation: a mode of ventilation that adjusts the amount of pressure used to keep the large airways open (typically 5-15mmHg), which helps to decrease the work of breathing
- Continuous mechanical ventilation (CMV): a full breath is given each time the patient initiates a breath
Definitions
- Assist Control: For every breath initiated by the patient, a total machine volume/pressure will be delivered to the patient. If the patient does not trigger a breath on their own, the ventilator will deliver a breath at a preset rate
- Volume controlled: a mechanical breath is delivered at a preset volume
- Pressure controlled: a mechanical breath is delivered until a preset pressure is reached
- Pressure Support Ventilation: here the patient may not need full ventilator assistance but is not yet strong enough to maintain adequate oxygenation and ventilation for themselves or they are still unable to maintain their airway.
Improving oxygenation:
Positive End Expiration Pressure (PEEP) can be raised to improve oxygen exchange, typically 5-20 mm Hg. PEEP is used to increase functional capacity, or the volume of gas retained in the lungs at the end of exhalation.
FiO2: increases the amount of oxygen delivered with each mechanical breath. The goal of oxygen therapy is to maintain a saturation of 93-96% in patients without underlying chronic pulmonary disease, and at 88-92% in patients with chronic respiratory failure and/or severe COPD.
Inspiratory to Expiratory ratio: (I: E) normally this ratio is 1:3 meaning it takes longer to expire than it does to inspire. By decreasing the ratio to 1:2 or 1:1, this allows more time to inspire in oxygen, but it will cause the CO2 to rise. This technique can also cause breath stacking and lead to a pneumothorax.
Permissive hypercapnia comes from allowing lower minute ventilation (which is the respiratory rate x tidal volume) in patients with significant decreased lung compliance, as in ARDS. The higher respiratory rate or tidal volume can injure the alveoli, which would compromise oxygenation. As long as the pH can be maintained above 7.2, the increased CO2 is allowed in order to preserve lung function and maintain oxygenation. When using this technique in patients with COPD, the patient may also experience breath stacking with auto PEEP, meaning their end-expiratory pressure will be high or their peak pressures may be high indicating a risk for more barotrauma. If this occurs, discuss the case with the respiratory therapist who can help reduce the pressure in the lungs.
Improving ventilation:
Respiratory Rate: the rate is used to control the CO2 content in the serum. For patients with hypercapnia (PaCO2 > 40), an increase in rate, >20 breaths per minute, can improve this to help treat acidemia.
Tidal Volume: the volume of an inspired breath from ventilator can improve the PaCO2 such that the larger the volume, the lower the PaCO2. Normally the volume is set by either:
- Volume control: the ventilator gives a set amount of volume. The recommended tidal volume is 4-8 mL/kg, so a 70kg patient (ideal body weight) would have volumes of 280 – 560 mL per breath. Respiratory rates should be set at higher than normal, 18-25 breaths per minute. Peak pressures should be maintained at less than 30cm H2O, and plateau pressures at less than 15 cm H2O. This means that the patients should be ventilated at faster rates and lower tidal volumes to prevent barotrauma.
- Pressure control: the ventilator gives volume up until a certain pressure. The pressure should be set to give a volume of 4-8cc/kg. In general, pressures above 30cmH2O result in barotrauma that damages the alveoli, which consequently worsens CO2 and O2 exchange. This will typically occur in patients with decreased lung compliance as with ARDS. Using the pressure-controlled technique allows the clinician to deliver an appropriate volume without increasing the pressure.
Other considerations:
Providers should work closely with respiratory therapists to make sure each patient is getting the support they need from the ventilator and that the ventilator is not causing any morbidity.
Proper placement of an endotracheal tube is confirmed by end-tidal CO2 which should be about 35-45 mmHg and a CXR with the tip of the endotracheal tube approximately 2cm above the carina.
Patients on mechanical ventilation will likely require sedation and perhaps paralysis to improve oxygenation and ventilation.
There are several parameters used for extubation including the Rapid-Shallow Breathing Index and the PaO2/FiO2 ratio. In general, a PaO2/FiO2 ratio of 300 or greater, and a RSBI of < 80 indicate that the patient is ready to wean from mechanical ventilation. Patients should not be considered for extubation if they require an Fi02 of more than 40% or a PEEP > 5 to maintain oxygenation.
Links:
REBELEM: Simplifying Mechanical Ventilation – Part I: Types of Breaths
AAST: Mechanical Ventilation in the Intensive Care Unit
Annals of Thoracic Medicine: Rapid shallow breathing index
VIDEO: Behind the Knife Podcast: Ventilators – Simplified By Dr. Patrick Georgoff
NIH NHLBI ARDS Clinical Network: Mechanical Ventilation Protocol Summary
Did you find this information helpful?
Please consider joining SAGES or making a donation to the SAGES Education and Research Foundation so we can continue to bring content like this to the surgical community for free.
Helpful COVID-19 Links
SAGES will compile helpful links for surgeons and the medical community on this page. Please bookmark it and return often for updates.
The following is intended to provide our members with additional information to help manage surgical patients during the COVID-19 pandemic. SAGES has not thoroughly reviewed or authenticated the content below and we neither recommend nor endorse any of the information contained in the links.
- Society for Critical Care Medicine – Critical Care for Non-ICU Clinicians
- VIDEO: Making Your Own Reusable Elastomeric Respirator For Use During Covid-19 Viral Pandemic N95 Shortage
- REBELEM: Simplifying Mechanical Ventilation – Part I: Types of Breaths
- AAST: Mechanical Ventilation in the Intensive Care Unit
- Annals of Thoracic Medicine: Rapid shallow breathing index
- VIDEO: Behind the Knife Podcast: Ventilators – Simplified By Dr. Patrick Georgoff
- NIH NHLBI ARDS Clinical Network: Mechanical Ventilation Protocol Summary
- #CoVisuals: Visual guides for society-based COVID-19 Recommendations
- Weill-Cornell Medicine | New York Presbyterian | Columbia – Updated Recommendations for Conservation and Reuse of Personal Protective Equipment (PPE) and Other Supplies March 20, 2020
- CDC – Sequence for Putting on PPE
- Joint GI Society Recommendations
- Critical Care and COVID-19
- AIS Channel COVID-19 Videos
- ACS COVID-19 Guidelines for Triage of Emergency General Surgery Patients
- Protecting Surgical Teams During the COVID-19 Outbreak
- COVID-19 Guidelines for Triage of Metabolic and Bariatric Surgery Patients
- Minimally invasive surgery and the novel coronavirus outbreak: lessons learned in China and Italy
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Conversations about re-using N-95 masks: Stanford study: Summarizes evidence, and the results of testing by their materials science lab
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Conversations about re-using N-95 masks: UV Light study: 2015 study out of West Virginia
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Conversations about re-using N-95 masks: Cloth Masks Don’t Work: Vietnamese trial
- Saw Swee Hock School of Public Health (Singapore) COVID-19 Science Reports
- Digital screening tool to restart elective surgery during COVID-19 – SeamlessMD
More to come…
Sources:
SAGES Committees, Task Forces, Social Media.
COVID-19 Statement and Recommendations from the Asociación Española de Cirujanos
SAGES Community: The Asociación Española de Cirujanos (Spanish Association of Surgeons, AEC) has graciously donated the following documents for publication. Documents are in Spanish unless otherwise noted.
We are working on translations but have no timetable for posting. We hope that our Spanish-speaking colleagues find these useful and if you wish to assist with translations, please contact [email protected]
AEC – COVID-19 Position Statement – English
AEC – RECOMMENDATIONS FOR RESIDENTS OF GENERAL SURGERY IN THE FACE OF THE SARS COV-2 PANDEMIC
SAGES 2020 Is Postponed
Dear SAGES Members and Meeting Attendees,
In light of the recent concerns about COVID-19 and the growing number of travel bans placed on both international and domestic surgeons, the SAGES executive leadership and Board of Governors has elected to delay the SAGES annual meeting until August 12-15, 2020. This decision was NOT made lightly but was the only viable option in good conscience we could make to preserve the health and safety of our surgeon attendees and patients.
We are, however, still planning to hold our committee and board meetings as scheduled March 31 and April 1, but these meetings will be held virtually. If you are on a SAGES committee or our Board, stay tuned for login details and please continue to hold those same time slots for your participation.
If you have an abstract accepted for presentation, we realize you have worked hard on your research and do not wish to delay disseminating the information for another four months. Therefore, we will keep the manuscript deadline of April 4 and allow submission to Surgical Endoscopy and publication prior to the 2020 annual meeting.
For the move to August, there will be some changes to the meeting. Due to availability, the main event and sing-off will still be at the Rock and Roll Hall of Fame, but it will now be a kickoff event on Tuesday, August 11. This will be a great way to welcome back our colleagues in the spirit of SAGES.
The meeting hotels and convention center plans are otherwise unchanged.
Specific instructions will be sent to faculty, presenters, registrants and exhibitors later this week. Please wait for those messages, as our staff have been inundated with individual calls and emails. We apologize for any inconvenience this has caused our members and attendees and thank you for your understanding.
We think August in Cleveland will be phenomenal and we look forward to seeing all of you then. Remember, SAGES Rocks!!!
Thank you for your continued support.
Aurora Pryor, MD, MBA, SAGES President
Matthew Goldblatt, MD, SAGES 2020 Program Chair
Leena Khaitan, MD, SAGES 2020 Program Chair
Sallie Matthews, Executive Director