Covid-19 cases, who are developing severe ARDS / respiratory failure are requiring mechanical ventilation, and the number of such cases is increasing during this pandemic. However, even in the countries having advanced and robust health care facilities are failing to provide an adequate number of ICU beds and Ventilators for such increasing numbers of patients. Healthcare providers of many areas are now using one ventilator for providing mechanical ventilation to multiple patients simultaneously. As most of the ventilators can not provide differential ventilation (even those which can, are designed for two lungs at most 2 patients), is it safe to do so? As the compliance of the lungs of the different patients will be different, their PS, Vt and MV required will be different, how it can be feasible? Isn't there a chance of cross-infection / super-infection? Please opine and guide..
It is possible to treat several patients with a single ICU ventilator. The Society of Critical Care Medicine guidance on this is below.
https://www.gnyha.org/news/working-protocol-for-supporting-two-patients-with-a-single-ventilator/
However all the patients would have to be deeply sedated to prevent triggering. Patients with similar needs for oxygenation and ventilation would have to be cohorted.
Anaesthesia Machines can also be used as ICU Ventilators. The Society of Critical Care Medicine guidance on this is below.
https://www.asahq.org/in-the-spotlight/coronavirus-covid-19-information/purposing-anesthesia-machines-for-ventilators
As most elective surgery has been cancelled many anaesthesia machines are lying idle and available for use.
Another option would be to use portable ventilators that are normally used to transfer patients around the hospital. These are generally more similar to ICU ventilators than the ventilators used in the anaesthesia machines.
The availability of portable ventilators is also limited. Portable ventilators are usually reserved for intra- and inter-facility transfer of patients.
Once all of these options have been exhausted the last resort would be to train patient's relatives to manually ventilate (‘bag’) patients. This is not uncommon in the developing world where ventilators are a scarce commodity at the best of times.
Whilst the use of medical students to ventilate patients during the Polio epidemic in Copenhagen in 1952 resulted in the birth of modern intensive care units I sincerely hope that we do have to face that scenario again.
The next question is then which of these options should be used first.
If patients require invasive mechanical ventilation and only the portable ventilators are available I would have no choice but to use them. Before using portable ventilators or using ICU ventilators to ventilate several patients I would use the anaesthetic machine ventilators in operating theatres. This would also allow the use of anaesthetic vapours for sedation of these patients. This may be critical when supplies of propofol and opiates are limited. Anaesthetic machines are generally kept within operating theatres so the use of these theatres also facilitates infection control.
After the anaesthetic machine ventilators were all used I would then start cohort ventilating up to 4 patients with similar degrees of lung injury per ventilator.
In conclusion: in principle I would prefer to use the operating theatre ventilators before cohort ventilating patients with ICU ventilators or using the portable ventilators. This is so that I can still perform inter- and intra-hospital transfers of ventilated patients.
However this decision making is complex and will vary with the resources available at individual centres. Modern intensive care ventilators are much more sophisticated than those used in operating theatres. ICU ventilators have many more modes of ventilation than operating theatre ventilators.
Some portable transfer ventilators are much more sophisticated than those used in operating theatres (e.g. Hamilton T1) and have the full functionality of intensive care ventilators. Some portable ventilators are less sophisticated (e.g. Oxylog 2000) than even the operating theatre ventilators.
Anaesthetic ventilators can function continuously and even allow the use of anaesthetic vapours for sedation. This may be relevant if supplies of propofol and fentanyl etc are depleted.
So whether it is safer to use the portable ventilator or the operating theatre ventilator depends on which of each type of ventilators you have. Regardless, in my experience, the humidification of gases using a HME (as is standard in the operating theatre and with portable ventilators) is not as effective as the wet circuit commonly used with ICU ventilators. So the risk of mucus plugging is higher.
Article Checklist Proformas to Guide and Document the Assessment of ...
The anaesthetic and portable ventilators are not as effective as intensive therapy unit (ITU) ventilators. Rather than using the same settings as we would with ITU ventilators, I therefore recommend that we adjust the settings on these ventilators according to frequent measurements of oxygen saturation, end tidal carbon dioxide, arterial blood gases, lactate and haemodynamic parameters. This is labour intensive and will require the assistance of staff who regularly care for ventilated patients but do not routinely work in ITU (i.e. anaesthetists).
So, as the COVID 19 pandemic progresses we will need to upskill colleagues to facilitate the assessment and treatment of critically ill patients with and without COVID 19. This may be achieved by face-to-face education sessions. However this is very labour intensive and may result in spread of COVID 19 amongst healthcare professionals.
An alternative approach would be to use standardised checklist proformas for the assessment of critically ill patients (see link below).
Article Checklist Proformas to Guide and Document the Assessment of ...
I would be most grateful if you could consider this question
https://www.researchgate.net/post/We_urgently_need_to_train_more_staff_to_work_in_intensive_care_units_to_treat_critically_ill_patients_with_Covid-19_How_can_we_do_this_now
Thank you very much for your detailed and insightful comments. It is really helpful. May I know your opinion on ventilating more than 2 patients with single ventilator?
Hi Habib, it is possible but the real question is if it is safe. One ventilator could deliver volume, flow and pressure at the exit of it's inspiratory port, but can it deliver differentially to each patient? We could measure flow and volume at each inspiratory arm, but if we do not have a restriction valve at the same point the result will be that the lung with more compliance will be filled first and more with the obviously risk. There is a lot of people trying to solve this problem with low cost equipment. See this link https://medium.com/@pinsonhannah/a-better-way-of-connecting-multiple-patients-to-a-single-ventilator-fa9cf42679c6
I know this is not a scientific source, but it could help you to find another approach.
I am absolutely agree with Tomas observation. I think that is very difficult (or impossible) to manage two patiens paralel in one machine. This is a desperate manage in state of huge number of patients who need ventilators. Fortunately, up to now, here we don't have need for manage like this.
I recommend you to look at this consensus.
https://www.aarc.org/joint-statement-guidance-document-on-multiple-patients-per-ventilator/
The consensus statement includes the following organizations; 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).
Thank you very much, all. It appears that most of us are ready to use one ventilator simultaneously for more than one patient for ventilation in desperate measure. However, it is also to be agreed that this not safe for the patients. The AARC in their Joint Statement on Multiple Patients Per Ventilator (SCCM, AARC, ASA, APSF, AACN, and CHEST Share Unified Message) advocates against this with reasonings. So, as far as possible, we should be avoiding this. Thank you once again for your inputs.
Everything in medicine balances risk and potential benefit.
In a crisis situation when I have to intubate a patient but there is no ventilator is available then I would share the ventilator rather than choose which patient should be ventilated.
Is sharing a ventilator less safe than using one ventilator per patient. Not ventilating a patient who needs it will inevitably result in death.
These are difficult times and difficult choices will have to be made.
Hi Habib:
The following articles could help answer some questions with this topic:
Article One ventilator for two patients: feasibility and considerati...
Preprint Adaptive split ventilator system enables parallel ventilatio...
Using one vent for multiple patients is not recommended currently unless there is a grave necessity.
I hope and pray that patients are cared well
One month ago we started here to discuss about possibility to manage two patients with one ventilator machine. Month later, after our and worldwide experience, it is obvious that type of management is unnecessary. Even, we learned that intubation in these patients is not first step in treating! All our patients, who were intubated, spent long time on machines, with many additional respiratory complications. Patients in whom we performed early and often changes to prone position and to supine position had better outcome and shorter stay in ICU.