Author: N. Martin Giesecke, M.D.
ASA Monitor 02 2018, Vol.82, 4-5.
Out-of-the-operating room (NORA, non-operating room anesthesia) anesthesia care is certainly one of the growth areas of many anesthesiology practices. And despite this being an area of increasing case numbers, there is sometimes trepidation on the part of physician anesthesiologists about providing care in these locations. When administering anesthetics for patients outside of the O.R., more often than not we are well out of our usual comfort zone. For instance, in my practice, one group of patients we care for are the left ventricular assist device (LVAD) patients who need to undergo gastrointestinal endoscopy procedures. You see, we provide anesthesia care for a heart failure service. We are there for every LVAD placement and all extra-corporeal membrane oxygenator decannulations. Of course, we do anesthesia for heart and lung transplants. Thus, we are there when the LVAD patients need to have endoscopies.
The reader is probably familiar with the fact that most LVADs these days are non-pulsatile. If an LVAD patient is recovering relatively well, they may have a pulse as a result of some return of their native cardiac function. If not, they will not have a pulse. They have perfusion and a “cardiac output” provided by the LVAD, but they may not have a pulse. And even those with a pulse often lose it when they are given some propofol for an endoscopy procedure. This puts us, as physician anesthesiologists, in the position of having to determine the adequacy of perfusion in a patient who cannot be monitored with a pulse oximeter or a non-invasive blood pressure (NIBP) device. Talk about being out of one’s comfort zone.
When I first started doing these cases (probably at least 15 years ago), I was adamant that I place an arterial catheter so I could see a pressure. Most of the patients we did at the time were still in the ICU, so placing an arterial catheter seemed appropriate. These days, many of the patients are coming into the GI suite from home, and using invasive pressure monitoring seems a bit too much. Obviously, if the LVAD is connected to its control console, we can see the flow (cardiac output) and revolutions per minute (RPMs). Still, my group has decided to measure cerebral oximetry to ensure that we have continued, adequate blood flow to the brain, once we have given propofol and lost the pulse oximeter and the NIBP.
Now reconsider the paucity (and yet, eloquence) of monitoring a patient with only cerebral oximetry. As long as the patient doesn’t lose much intravascular volume (blood) with the endoscopy procedure, their LVAD flows and RPMs should remain stable. We are able to ensure adequate cerebral blood flow with an unchanging cerebral oximeter reading. This is in tremendous contrast to the monitors a cardiac anesthesiologist normally has at his or her disposal: arterial catheter, TEE, PA catheter, etc. Also consider that in the GI suite, we are often the only physician, maybe the only person, who knows how to resuscitate a patient. And we don’t have our typical O.R. setup – including ready access to in-fusion pumps, invasive monitoring, etc.
A number of developing NORA sites are pediatric dental practices. With the press given to bad outcomes of dental sedation and anesthesia (without the input of a physician anesthesiologist), many dentists are taking the high road and requesting that a physician anesthesiologist provide anesthesia forthose cases where more than local anesthesia and reassurance are needed. The pediatric anesthesiologist is now working outside the pediatric O.R., that arena where they feel most at ease providing an anesthetic. How do they manage? Are all general anesthetics done solely with propofol? Are all patients intubated? With the childhood obesity epidemic, where do they draw the line on which patients must be cared for in a standard O.R. (either at a hospital or an ambulatory surgery center)?
Certainly, one of the arguments for NORA is the overall lower cost of care for the patient. Though the surgeon or the dentist may still bill a facility fee, that amount tends to be much lower than a hospital or surgical center cost. So as long as we are able to provide a safe anesthetic, why not do so where the financial cost to the patient is significantly lower? Some insurers are pushing this trend, but so are budget-conscious patients with high co-pay insurance plans.