Addressing Scarce Resources in the Covid-19 Pandemic: Ventilator Sharing
First of all, an enormous thank you to all healthcare workers- especially those on the frontlines-for your selfless dedication during this unprecedented crisis.
K2P is working to help keep our clinical audience informed of topics of interest at this time. If you missed our interview with Angela DeJulius, MD regarding the collaboration between public health and clinical practice, you can check it out here.
In certain geographic areas, healthcare systems are overwhelmed with the volume of patients flooding hospitals and particularly, intensive care units. In limited supply are N-95 masks (protecting against at least 95% of airborne particles), related personal protective equipment (PPE) and ventilators.
One of the potential strategies considered to address the shortage of ventilators during this surge is the shared, or split, use of a single ventilator between 2 (or more) patients.
Earlier this week, we spoke to Ashish Khanna MD.,FCCP.,FCCM, Associate Professor, Section Head for Research, Department of Anesthesiology, Section on Critical Care Medicine, at the Wake Forest School of Medicine, to gain his insight on this practice and help us understand the operational complexities of this approach.
Dr. Khanna began by sharing that he and other experts concur that this solution would be born of dire need, and is far from ideal. Other surge tactics that may be considered in crisis situations like this include short term manual ventilation (with the attendant need for additional staff) and the adaptation of other mechanical ventilation devices, like those employed by anesthesiologists intraoperatively, to function in the ICU setting.
In addition to the obvious concern around cross-infection (which can be partially mitigated with use of filters), with the split ventilator system use comes the challenge of the loss of individualized ventilatory settings based on individual patient characteristics and needs. Ventilator settings in the ICU are customized and constantly titrated by the intensivist to each patient’s clinical situation. Varying driving pressures are required to achieve the same tidal volume according to each patient’s lung compliance, ideal body weight, body habitus, and underlying pulmonary status among other factors. A critical tactic of multi-patient ventilation is to prevent any patient from affecting the other patients sharing the ventilator.
A sudden pressure change caused by a mucus plug, a sudden pneumothorax, or dislodgment of an endotracheal tube would potentially affect all patients attached to the ventilator. Though, ventilator circuits in parallel may potentially mitigate this risk, there may still be an inherent risk that would be much greater than individualized patient ventilators. Settings that allow one patient’s spontaneous respiration to trigger the ventilator could lead to subsequent tachypnea in another patient. Weaning patients individually as indicated would also not be doable. Audible ventilator alarms would be significantly more confusing for the team taking care.
The addition of positive end-expiratory pressure (PEEP)- an important option in these patients- would be impossible to manage, and a more or less ‘one size fits all’ PEEP approach would need to be adopted.
Since Dr. Khanna and I spoke, on March 26, The Society of Critical Care Medicine (SCCM), American Association for Respiratory Care (AARC), American Society of Anesthesiologists (ASA), Anesthesia Patient Safety Foundation (APSF), American Association of Critical‐Care Nurses (AACN), and American College of Chest Physicians (CHEST) issued this consensus statement on the concept of placing multiple patients on a single mechanical ventilator.
In addition to the points made by Dr. Khanna, the consensus statement also touches on a key ethical issue during this challenging time. In the context of all of these limitations and risks, shared ventilator use could increase the morbidity and mortality risk of both (or all) patients. In accordance with the triage decisions necessary in unusual times like these, it seems prudent to “purpose the ventilator to the patient most likely to benefit than fail to prevent, or even cause, the demise of multiple patients.”