Episode #35 Powerful Anesthesia Patient Safety Questions and Considerations

Hello and welcome back to the Anesthesia Patient Safety Podcast.  My name is Alli Bechtel and I am your host. Thank you for joining us for another show.

Today on the show we are covering 2 powerful patient safety areas that are featured in the February 2021 APSF Newsletter. Have you seen the newest Newsletter yet? If not, as soon as this show is over, click over to APSF.org and click on the Newsletter heading, first one down this time is the Current Issue and if you hover over it, you can see that it is available in Spanish, Portuguese, Japanese, French, and Chinese.

Before we dive into today’s episode, we’d like to recognize Masimo, a major corporate supporter of APSF. Masimo has generously provided unrestricted support as well as research and educational grants to further our vision that “no one shall be harmed by anesthesia care”. Thank you, Masimo – we wouldn’t be able to do all that we do without you!”

The first topic that we are going to talk about today is the Case Report, “Anesthesia Machine as an ICU Ventilator – Near Miss During COVID-19 Pandemic” by Levin and colleagues. You may have seen this on the APSF website, but it has been updated for this newsletter release. In the spring of 2020, in New York City the COVID-19 pandemic led to a significant increase in patients requiring mechanical ventilation. The demand was so high that anesthesia machines had to be used as ventilators in non-OR locations. This is an off-label use for these machines. You may have seen the APSF/ASA article related to this topic that provides helpful key points, called “Guidance on Purposing Anesthesia Machines as ICU Ventilators.” I will include a link in the show notes as well. This case report involves an anesthesia machine ventilator failure and illustrates important safety considerations when standard equipment is used in non-standard ways such as outside the OR and in areas of the hospital converted into temporary ICUs.

I reached out to one of the authors of this article and I will let him introduce himself.

[Levin] Hi, My name is Matt Levin. I am an associate professor of anesthesiology at the Mount Sinai School of Medicine in New York City.

[Bechtel] I asked Levin to share with us why he wrote this article. Let’s hear what he had to say.

[Levin] I wrote this article in order to make readers aware of unexpected ways in which an anesthesia machines can failure particularly when used in an unconventional location. In this case, we had converted a telemetry unit for use as a temporary ICU during the height of the COVID-19 pandemic in New York City in the Spring of 2020. The article describes the root cause analysis we performed in order to identify the surprising and unexpected cause of failure of the machine.

[Bechtel] And with that, are you ready to hear about the case? Here we go. A 66 year-old gentleman with a past medical history of type 2 diabetes developed acute respiratory failure due to acute COVID-19 infection. He was intubated and required mechanical ventilation. The authors describe the temporary set-up for negative pressure rooms and ICU care. The temporary rooms were converted into negative pressure rooms with the addition of a hardboard panel with a HEPA filter and extractor fan exhaust duct installed which replaced the exterior window. Instead of ICU ventilators, anesthesia workstations were used in the temporary ICUs and anesthesia professionals managed the ventilators in these rooms. Did you have to use an anesthesia machine as a ventilator during the COVID-19 Pandemic and ventilator shortage? Since there were no interior windows or windows in the doors in these temporary ICU rooms, a remote visual patient monitoring system was used so that the anesthesia professionals could monitor the patients from outside the rooms. The remote monitoring system was connected to a central station telemetry network with additional physiologic monitoring including high volume audio alerts for changes in rhythms and low volume audio alerts for decreased pulse oximetry.

The stage has been set, so let’s fast forward to hospital day #10 when an audible alarm sounded at the central station and the pulse oximeter displayed 45%. The healthcare team donned PPE prior to entering the patient’s room where they discovered the following: No mechanical ventilation, the extractor fan was off, the room temp was elevated, the anesthesia machine monitor was dark with the AC power indicator light off, and the physiologic monitoring system remained On and functioning. The team took quick action by disconnecting the patient from the anesthesia machine-turned ICU ventilator and using a self-inflating bag for manual ventilation which provided appropriate oxygenation and ventilation and pulse oximetry returned to baseline. Evaluation of the power supply revealed that the bed was plugged into the auxiliary outlet on the extractor fan, the fan was plugged into a floor-level electrical outlet, and the remote patient monitoring system was plugged into a separate floor-level outlet. The anesthesia machine turned on again after switching to a different plug with return of the AC power indicator light. The team completed an anesthesia machine checkout which passed and then the patient was placed back on mechanical ventilation through the anesthesia machine successfully. Once the patient was stable, the anesthesia machine was changed out for a new machine and the malfunctioning machine was interrogated. The Engineering team discovered that a circuit breaker for the room tripped and was reset. The extractor fan was re-started without further problem as well.

Further analysis revealed that the anesthesia machine workstation failed after a tripped circuit breaker interrupted the power supply to the workstation. This caused the workstation to switch appropriately to the backup battery. Since power was not restored to the workstation, the battery was drained to empty. Appropriate alarms were displayed on the anesthesia machine including Battery Low at 28 minutes after switching to battery power to Battery Empty at 1 hr. and 43 minutes after the switch until the workstation shut down at the 1 hr. and 52 minute mark. Unfortunately, these alarms were not visible to the anesthesia professionals monitoring the patient remotely.

This is an important case especially since many anesthesia professionals have not had to use an anesthesia machine as an ICU ventilator prior to the COVID-19 pandemic. For most cases, anesthesia professionals remain near the anesthesia machine whenever they are taking care of patients in the operating rooms where the visual and audio alarms can be clearly seen and heard while taking appropriate action to resolve these alarms, but in this case the anesthesia team monitored the patient from outside the room and were unable to see these visual alarms.

Some of the keys points for this case include safety concerns with newly created temporary ICUs during the pandemic, use of an anesthesia machine as an ICU ventilator, safe remote monitoring for patients with COVID-19. The battery supply for ICU ventilators and anesthesia workstations is also a consideration since ICU ventilators may have a battery life of about 1 hour while similar anesthesia workstations may have a battery life of 50-90 minutes or even longer in this case. The power supply to the temporary ICU room included 2 x 15Amp circuits with white outlets, 2 x 20A circuits with white outlets that shared a connection with the adjacent room, and one 20A emergency circuit with red outlets. The circuit trip most likely occurred due to exceeding one of the 15A circuits from the connections of the extractor fan, remote patient monitor, anesthesia workstation, and the bed. The ICU bed can draw up to 12A and the extractor fan requires an additional 2.5A so it is easy to see that this circuit could be tripped. An important safety concern that came up as part of this case was the delay in restoring power to the room since this required the hospital engineering team to access the locked circuit breaker panels. The Covid-19 pandemic has delivered unique clinical care scenarios and threats to patient safety. While the recommendations for using anesthesia machines as ventilators strive to maintain patient safety with an anesthesia professional be immediately available and participating in hourly rounds, this may not always be possible depending on the number of ventilated patients and limited staff. It is also important to note that this could have occurred with an ICU ventilator as well if the power supply was cut off. Some of the newest ICU ventilators have the option for remote monitoring and perhaps going forward we will see this technology incorporated into ICU ventilators and Anesthesia Workstations more often. Thank you to the authors for sharing this case report and highlighting the importance of vigilance to maintain patient safety and this is especially crucial during crisis management situations including off-label use of equipment in unfamiliar environments with limited staff and resources.

Before we move on to the next article, I also asked Matt Levin what he hopes to see going forward related to this area?

[Levin] I hope to see more education around the subject of unexpected failures of anesthesia machines and root cause analysis. I also would hope to see new developments from manufacturers that enable easier remote operation and monitoring of anesthesia machines particularly when they are used in unexpected locations.

[Bechtel] Thank you so much to Matt Levin for his insight into this challenging case with ideas for improved patient safety going forward.

The case we just talked about involved interrupted external power supply and we are going to continue to explore this area of power supply by reviewing one of the newest rapid responses from the February 2021 APSF Newsletter. This Rapid Response comes to us from Chante Buntin. You can find the article by clicking on the Newsletter heading and then first one down is the current newsletter. Then scroll down until you see the Rapid Response column on the left. Click on Emergency Power and Elective Surgery.

I hope that you have a full charge on your podcast listening device because here we go. Buntin writes,

“Dear RAPID Response:

I read your safety guidelines often for answers, but I could not find one that addresses the question of what types of procedures should be done when only emergency power is available. Specifically, is there any information about the advisability of performing an “elective” surgery during a known black-out and using a back-up generator?

I am aware of a surgeon who is planning elective surgery during power outages related to wildfires and relying solely on back-up power sources for the day.

The surgeon wants some sort of published guidelines stating it is a bad idea to do elective surgery on backup power. Do you know of any?

Thank you for any helpful information you can provide.”

This is a great question and a valid patient safety concern. Feldman and colleagues provide some answers with their response. Unfortunately, there are no guidelines about performing planned elective surgery with an emergency power supply, but there are some guiding principles that may be helpful.

First, emergency power supply availability and limitations depend on the institution.

Second, the emergency power supply has limitations when compared to the standard non-emergency full power supply.

And finally, the limited emergency power supply may be needed for urgent and emergent patient care and operations, but if the emergency supply is used for non-emergent procedures then this may have a down-stream impact on the ability to be able to provide urgent and emergent care that cannot be delayed safely.

There are standards and codes for power requirements in health care facilities that must be followed in the US according to the Center for Medicare and Medicaid Service and Joint Commission.  The standard is that there must be 2 independent sources of power and one of these power sources must be on site which is usually a generator which will have different electrical capacity and fuel supply depending on local authorities.

Let’s dive a little further into the power supply and distribution according to the NFPA’s National Electrical Code. The first  supply line is the Life Safety Branch which provides power to exit signs, door unlocking mechanisms, alarms, and emergency hallway lighting. The next line down is the Critical Branch which supplies clinical equipment plugged into the red outlets in the OR and ICUs and nursery as well as the nurse call systems and the pharmacy storage. The final supply line is the Equipment Branch which as you can probably guess provides power to all other pieces of electrical equipment.

The question about what can and should be done during periods requiring the emergency power supply depend on the number of generators on site as well as the generator capacity and fuel supply. It is also important to consider the time period for the emergency power supply. With that, let’s get into some technical talk. You might want to have your pencils ready. NFPA 110 is the standard for emergency and standby power for facilities. Class X designation is given to hospitals which allows these facilities to determine minimum needed run time based on the size and needs of the hospital and local safety codes. NFPA 99 is the standard for fire and life safety requirements and offers guidance for generator run times that includes recommendation for adequate fuel supply depending on the determined emergency electrical supply run time with consideration for different types of outages, may include weather related outages. It appears that 48 hours minimum run time for emergency generator power is often used, but in areas that must be prepared for a major earthquake, this minimum time may be increased to 96 hours.  The other thing to keep in mind is that generators may not be guaranteed power and may fail which was known to occur during Hurricane Sandy. After the utility power stopped and the generator power supply failed, a major academic center was left with a complete power failure.

Perhaps an appropriate course of action is to work with the facilities management to determine the capacity for emergency electrical supply at your institution. The authors provide us with questions to ask that can be used to help provide safe and timely care to our patients in the face of a power outage. What is the max power of the generators? What is the anticipated power needs for the institution during the power outage? How many generators are available? What is the available fuel supply and how long will the generators be able to run with this supply? What is the power supply required to care for existing patients as well as to provide urgent and emergent care? The answers to these questions can mean the difference between being able to provide necessary care and complete power failure. Depending on the answers, it may mean that patients can have elective surgery performed during a planned  and limited emergency power supply time period and it may mean waiting until utility power is restored.

This was a great Rapid Response to review. Thank you to Chante Buntin for this article.  That is all the time we have for today. If you have any questions or comments from today’s show, please email us at [email protected].

Visit APSF.org for detailed information and check out the show notes for links to all the topics we discussed today.  Plus, you can find us on twitter, Instagram, Facebook, and LinkedIn!  See the show notes for more details and we can’t wait for you to tag us in a patient safety related tweet or like our next post on Instagram!! We are so excited to continue to grow our Anesthesia Patient Safety Foundation Family!

Until next time, stay vigilant so that no one shall be harmed by anesthesia care.

© 2021, The Anesthesia Patient Safety Foundation