There is a lot of talk lately about ventilators and the potential need for many more of them in the near future; hopefully, that eventuality will not be realized.  As has been noted, a ventilator is a sophisticated "breathing machine" and a staple of the ICU, where they are used to "breathe" for critically ill patients who are usually sedated and often given medications to relax their muscles. 

While anesthesia departments will never be a front-line source of ventilators, their anesthesia machine ventilators are used daily in the same way for patients undergoing anesthesia for all kinds of surgery and could be pressed into service if needed. 

Obviously, O.R. suites cannot be emptied of all their anesthesia machines, but the fact that most providing institutions have ceased doing elective surgical cases frees up many of these machines — contingent, of course, on local conditions and resources.

Though most of these machines are found in hospital operating suites, they are also found in ambulatory surgery centers, office-based surgery practices, and anesthesia equipment–distributor centers also.  They may also be found in some dental surgery suites.

Decades ago, ventilators were often an adjunct to the anesthesia machines then in use.  By the '90s, they were an essential part of that machine and have became increasingly more sophisticated ever since.  They are capable of providing the mechanical ventilation for patients who are in respiratory failure due to the acute pneumonias often seen in critically ill COVID patients.  However, unlike in the O.R. suite, where a surgery may be an hour or maybe ten or more, a critically ill COVID patient with a pneumonia may require days of ventilation.  Anesthesia machine ventilators are not approved by the FDA for long-term ventilatory support.  So use in a ICU setting would be a kind of off-label use — a term often heard now in conjunction with some of the medications pressed into use during this crises.

The APSF (Anesthesia Patient Safety Foundation) and the ASA (American Association of Anesthesiologists) have sponsored a document to provide guidance on using anesthesia ventilators safely and effectively in the ICU setting.  They do differ from ICU ventilators, though they can provide almost all the functions of one.  However, they will also require qualified anesthesia-providers to put them into service and manage which in itself may be one aspect of manpower relief..