Using one ventilator for multiple patients

As a medical device manufacturer, Hamilton Medical assumes an extremely high level of responsibility for patient and user safety. Their safety can only be guaranteed when the devices are used as intended, i.e., one patient per device. Non-intended usage of our ventilators for multiple patients may lead to unpredictable complications.

Therefore, Hamilton Medical cannot recommend the use of one mechanical ventilator for multiple patients. To ensure appropriate and lung-protective ventilation, monitoring and ventilator settings need to apply for each individual patient. This is made possible by the proximal flow- and pressure-measurement technology in our devices.

If you use our ventilators on a patient-to-ventilator ratio of greater than 1:1, be aware that:

1. The inability to directly measure volumes delivered to the individual lungs will most probably result in distending (and damaging) the healthier lungs of the ventilated patients, while the lower compliant lungs will collapse further.
2. A multi-ventilator strategy will not allow for optimized CO2 clearance.
3. The increase in artificial airways (breathing tubes) will reduce the ventilator's performance (pressures will be lost due to circuit/breathing tube compliance).
4. The only recommendation with respect to positioning the proximal flow sensor is to put it at the Y-piece of the ventilated patient. So which patient will you choose?
5.  Recommendations for COVID-19 and ARDS patients include tidal-volume monitoring and limitations, and individual PEEP settings: How can you make sure this works for two patients on one ventilator?
6. Ventilating multiple patients will mean one patient’s interaction with the ventilator interferes with the ventilation of another patient.
7. Weaning the patient from the ventilator is one of the most important ways to ensure the availability of ventilators. How can you be sure you can wean your patient with the likelihood of total asynchrony between patient and ventilator?
8. Running two patients on one ventilator will also involve serious hygiene issues. Patients may also have additional pathogens like multi-resistant bacteria or other viruses, etc.
9. Important procedures like prone positioning will not be possible in such a setting.

Should you run out of ventilator equipment, we recommend instead:

• Informing the local authorities and asking for help
• Informing the Clinical Direction: All non-essential treatment (surgery, endoscopy, examinations, etc.) should be postponed to free up all ventilators within the hospital
• Informing the operating-room department: Ask for anesthesia devices, transport ventilators, old ventilators in the basements and whatever works within its intended use
• Asking hospitals in the region for help (ventilators): Local authorities may have to step in as private hospitals may not be willing to rent their ventilators
• Asking private surgical centers for their anesthesia devices: Support from local authorities may be needed here as well
• Trying to use NIV devices instead of invasive ventilators wherever possible (however, not on COVID-19 patients)  and getting patients weaned and extubated as soon as possible
• Trying to reduce the number of COPD patients who have their own sleep apnea devices, but are connected to an ICU ventilator in hospital. Try to bring these patients back to a state where they can be ventilated on their own equipment

Full citations below: (Branson RD, Blakeman TC, Robinson BR, Johannigman JA. Use of a single ventilator to support 4 patients: laboratory evaluation of a limited concept. Respir Care. 2012;57(3):399-403. doi:10.4187/respcare.012361​)