There is nothing quite as scary as being in the middle of administering an anesthetic and having your anesthesia machine fail. In my 36 years of anesthesia practice I’ve had this happen to me a few times. Knowing how to quickly troubleshoot your machine, and knowing how to protect your patient are important, potentially life-saving skills. It helps to have thought through the steps to rescue the situation before it happens to you.
Here I describe how I learned this lesson the hard way on a volunteer medical mission to rural Honduras. When my machine failed, I was poorly prepared and this forced crisis management that I could easily have avoided with a little forethought and preparation.
My First Machine Failure: Honduras 1986
The first time I faced an anesthesia machine failure was with a small surgical team to Honduras. At the time, I was volunteering for two weeks in a tiny mission hospital that consisted of one operating room, two postop wards, and a preop staging room. The hospital was surrounded by a bean field next to a farmhouse about 100 miles outside of Tegucigalpas. Some patients arrived by horseback. Our team consisted of myself for anesthesia, a surgeon, his surgical resident, and an OR/ward nurse.
The hospital had an ancient Forreger Anesthesia Machine, a machine type I had never worked with before. This Forreger had its common gas tube running parallel at the top of the machine that channeled the anesthesia gas oxygen mixture into the ventilation bag and circuit. The machine had worked well for the first two days giving anesthesia to many small children who were breathing spontaneously after induction. Small breaths, very little circuit pressure. In the photos below, the red arrow points to the common gas bar.
While we were there a young farmer walked into clinic with an 8 inch machete wound to his forehead that penetrated his frontal sinus at several spots, the result of a fight. He had bilateral black eyes, He had been unconscious for an unknown number of minutes after the injury and clearly had had a recent concussion. The fact that he had walked 5 miles to the clinic implied that any brain injury was probably not severe.
Being in the 1986 Honduran countryside there was zero ability to obtain any sort of CT scan or even an Xray to rule out intracerebral involvement. However, leaving this unrepaired with an open sinus would have placed him at high risk of infection, potential meningitis and death. So we decided to proceed.
Being concerned that he might have potential for increased intracerebral pressure, I decided to take precautions and treat him as though he had a known brain injury. I would get him deeply anesthetized before intubation with a large dose of pentothal to prevent hypertension, I would give a large dose of muscle relaxant so that he could not cough during intubation putting stress on his brain. I planned to hyperventilate him after intubation to decrease his PaCO2 and thereby decrease any brain swelling. I administered my induction agents, quickly and easily intubated the man and rapidly began to hyperventilate him with large tidal volumes.
What I didn’t know but was about to find out was that this Forreger machine had a faulty gasket that allowed pressure from squeezing the ventilation bag to channel back into the machine. Giving large adult sized tidal volumes over-pressurized the tubing inside the machine and popped the common gas bar out of the top of the machine. The bar promptly rolled under the operating table. Without it I might as well have been giving anesthesia with a Volkswagen car. My anesthesia machine was now useless and I had a paralyzed, unconscious patient on the table who was at risk of further brain injury and intracranial swelling. And if that wasn’t bad enough my only ambu bag was back in the farmhouse.
So while the missionary ran back to the farmhouse to grab the ambu bag, my surgeon did mouth to tube ventilation while I crawled under the table, retrieved the bar and reassembled my anesthesia machine. After verifying that I could indeed ventilate the patient reliably, and with the ambu bag now in the room, surgery proceeded.
My patient did fine. I, on the other hand, felt as though I had aged about ten years. This terrifying event impressed upon me that you always have to be ready for machine failure.
Always Have A Plan For Machine Failure
When an anesthesia machine fails, you can’t panic. You must systematically approach the problem putting patient safety first. Steps you should follow include:
- Announce the problem and organize your team
- Oxygenate and ventilate your patient
- Maintain an adequate level of anesthesia if surgery has started
- Fix or exchange the anesthesia machine
- Monitor the patient while all of these steps occur
- Maintain sterility of the operative field as best you can
Let’s look at these steps in more detail.
Announce The Problem and Organize
You can’t handle this by yourself. In Honduras I had to alert my team and then tell them what I needed them to do. They had no idea how to help without me giving them directions. Clear and non-panicked communication is key.
The first question you need to ask yourself is how critical is this malfunction? Switching out an anesthesia machine is a risky sequence of events that can place your patient at risk and can potentially injure your teammates as they move heavy equipment around quickly.
For example if your anesthesia machine works but the attached monitor stops working, can you continue the case with a transport monitor using the original machine? If the machine cannot deliver anesthetic gas because the vaporizer fails, but you can ventilate and oxygenate could you switch to total intravenous anesthesia to finish the case? If the machine delivers anesthesia gas and you can ventilate, but part of the data screen is not working can you make do until the case is over?
Don’t hesitate to change machines it you think it’s unsafe to continue, but don’t take such as exchange lightly either.
Oxygenate and Ventilate
Obviously in Honduras I had only one anesthesia machine — I had to make it work or wake up the patient. I was lucky that machine failure had occurred right after induction and before surgery had started. Had I not been able to fix the anesthesia machine, as long as I could ventilate the patient I could have allowed the patient to awaken as the drugs wore off and resume spontaneous ventilation. I then could have approached fixing the machine in a more leisurely manner.
You should always have some alternate means of oxygenating and ventilating a patient present in the room in addition to your anesthesia machine. Usually this is a self-filling ventilation bag. In my Honduras case, my only choice due to my own lack of preparation, was mouth to tube ventilation. Not the optimal choice but it worked.
Having a separate ventilation bag is not only key preparation for possible for machine failures, it’s also a standby for other emergencies such as the need to evacuate the OR in case of a fire, or the need to ventilate a patient with a gas free mixture during treatment of an acute malignant hyperthermia crisis.
If you must use a flow-dependent ventilation bag you must bear in mind how much supplemental oxygen is in your tank.
If your patient can breathe spontaneously, even if assisted, this may add a measure of safety.
Maintain A Level Of Anesthesia
The situation becomes more complicated if the machine fails after surgery has already begun under general anesthesia. Now you have to maintain some adequate level of anesthesia, with unconsciousness and pain relief while you or your team are repairing or replacing the anesthesia machine.
Without the machine you become dependent on giving fixed intravenous agents such as propofol and narcotics. It’s easiest to quickly set up an infusion if you have this option because this provides some additional control of titratable medications, allowing you to concentrate on other things. However you can simply bolus these medications as needed in the acute situation.
Fix Or Exchange The Machine
Fix the machine if you can. If you can’t easily fix the machine you will have to quickly switch it out for a spare if you have one. This is not always easily done in a small operating room crowded with laparoscopy towers, tables full of sterile instruments, bovie machines and suction equipment. In addition, most anesthesia monitors today are mounted on top of the anesthesia machine: removing the machine usually means taking the monitors off the patient and out of the room.
Organize your team for the following steps:
- Bring a transport monitor to the room and attach it to your patient. That way you will be able to monitor your patient’s response to your now IV anesthetic during the exchange by watching pulse, EKG, pulse oximetry and blood pressure.
- Someone must bring and optimally check the new machine before it’s brought into the room. Extra machines sitting in the hallway or workroom sometimes have parts borrowed and not returned. You want to know it’s going to work before you start moving things around.
- The OR team must clear a path for the old machine to exit and for the new machine to come in. They can be doing this while the new machine is checked and brought.
- The surgical field should be covered and the surgery stopped if possible during this event to maintain sterility. Depending on the type of surgery this may or may not be possible. Keep your surgeon in the loop.
- Take out the old machine and bring in the new one. Attach it to your patient and switch anesthetics.
- Verify that your patient is stable and anesthetized. Ensure that the surgical field has not been compromised. Consider additional antibiotics if you’re worried the field was contaminated.
What If You Can’t Fix It And There’s No Spare?
If you can’t fix the machine and there is no spare then you may need to consider moving the patient to another OR to finish the case. This action, which is basically an evacuation of your OR, is a major undertaking that increases the risk of infection. This is a decision that should not be taken lightly.
Second Case: San Diego 2016
That Honduras case was decades ago and involved an ancient, out of date anesthesia machine. Machine failures don’t happen with modern equipment, right?
Fast forward to several months ago. As anesthesiologist in charge that day, I was called to assist in an OR because the team was having difficulty ventilating a patient. I ran into the room. The anesthesiologist had just induced, paralyzed and intubated the patient. He had then tried to ventilate using the anesthesia machine. The machine, which had checked out perfectly fine not 30 minutes before now could not deliver positive pressure.
The anesthesiologist was now ventilating with an ambu bag while his teammates were trying unsuccessfully to get the anesthesia machine to work. The circuit simply would not hold pressure. No one could find the source of the crippling leak. Like my case in Honduras, surgery had not as yet started so wake up was an option. However, we could easily ventilate by ambu bag and had a spare anesthesia machine immediately available.
So we followed the protocol:
- Ventilate the patient
- Attach a transport monitor
- Keep the patient anesthetized with propofol, but keep the option of waking the patient up open. We had suggamedex in the room to reverse the muscle relaxant if needed.
- Clear a path and remove the old machine while the new one was checked
- Bring the new machine
- Begin anesthesia and attach the new monitors
It took less than 5 minutes to switch out the machine because we worked as a team and knew the steps that needed to be taken.
After the emergency was over I checked out the old machine that was now in the workroom. I found that the plastic CO2 absorbent canister had a big hole in the bottom, something we missed in the middle of the crisis — after all the machine had checked out, how could there be a hole?
That’s when I found out new information. Between the time the machine had been pre-checked prior to bringing the patient into the room and the induction, every piece of equipment had been moved to the opposite side of the room to allow easier surgical access to the patient. The machine never got checked again after the move. Somehow during that move from one side of the room to the other the canister got struck by another piece of equipment and the bottom shattered, leading to a loss of circuit integrity.
This raises another important learning. Whenever a machine is moved, you should recheck it before you use it on your patient. Don’t just assume it’s still okay.
It takes a lot of coordinated and rapid effort to safely maintain an anesthetic and exchange an anesthesia machine. Always check your equipment before you start. If it’s moved, check it again. Always make sure you have another way to ventilate your patient. Good communication and teamwork are key.
Oh, and never, ever, leave your ambu bag back in the farmhouse!
May The Force Be With You
Christine Whitten MD, author Anyone Can Intubate, 5th Edition