PAs and AAs: Different Yet Similar

The use of nonphysicians to extend the quantity of all types of medical care without diminishing the quality of care has been ongoing since the late 1960s: this with the use of physician assistants (PAs). PAs are trained in the medical paradigm by physicians to practice medicine with physician supervision. It should be noted that there is no “PA” level of medical care. PAs are trained to know their limitations and to consult their supervising physician whenever there is a question. PAs may practice only within the scope of practice of the supervising physician. A PA graduates from his/her training program, passes the national certification examination, obtains licensure and then enters practice. The supervising physician’s preferences and the knowledge required for that area of practice are typically learned on the job.

Anesthesiology provides an awkward exception to the custom of on-the-job training. A practice hiring a PA has an expectation of certain knowledge and skills. While detailed specialty knowledge is not yet developed, a certain basic level of medical knowledge and experience is presumed. The PA who wishes to practice in anesthesiology needs to find a place where he/she will not be counted on to be a productive member of the anesthesia care team (ACT) for several years (akin to residency training). The practice hiring a PA must be willing to provide intense supervision and a guided educational experience to make the PA a functional member of the ACT. Another option would be to provide postgraduate training for PAs in anesthesiology to provide a more structured and uniform level of training.

Another member of the ACT does not need this training, the anesthesiologist assistant (AA). The AA graduates having the anesthesia knowledge base to immediately begin working with anesthesiologists. The AA does not have the broad-based medical experience of the PA; the AA has in-depth training to provide supervised anesthesia care upon graduation. Both PAs and AAs are required to have physician supervision; PA supervision must be by a physician trained in the area of practice, while only anesthesiologists can supervise AAs. PAs may practice in every state, although some states prevent them from specifically practicing anesthesia; unfortunately AA practice has not yet become so widespread across the United States.

Finally there is a newly formed association of PAs in anesthesia, a special interest group in the American Academy of Physician Assistants. There has been increasing interest in the use of PAs in anesthesia and how to train them. I will keep the ASA membership informed.

Shepard B. Stone, P.A.
Branford, Connecticut

Editor’s Note: PAs are not AAs, and this letter makes that distinction. Before hiring a PA, consult with your state anesthesiology society to determine if your health codes will allow them to practice anesthesia. In New York, the health code specifically delineates who can provide anesthesia. PAs and AAs are not listed and therefore cannot practice anesthesia in New York.

— M.J.L.

Visual Loss Data Need Another Look-See

The article published in the June ASA NEWSLETTER titled “ASA Postoperative Visual Loss Registry: Preliminary Analysis of Factors Associated With Spine Operations” by Lori A. Lee, M.D., needs clarification. In addition to clinicians’ interests in these devastating phenomena, many lawyers are looking at this information with similar interest.

Analysis of the data must be carefully performed since any suggestion of association can be easily misconstrued as causality. Ischemic optic neuritis can cause irreversible blindness as suggested by the author and supportive literature. We are concerned that the data used to support associated conditions are not qualified and leave the readers, whomever they are, to erroneous and damaging conclusions. Stated by the author “…the etiology — is unknown — multifactorial — associated with large blood loss, hypotension, anemia, — and/or vaso-occlusive disease….”

Myers et al. do not analyze other factors such as small vessel disease (i.e., diabetics or connective disorders), which could lead to optic ischemia.

Anemia may not be a true causative factor and transfusions may have a stronger correlation. Large blood loss is associated with both anemia as well as transfusion of allogeneic blood, known to have effect on capillary architecture (vaso-occlusion). Stored erythrocytes undergo depletion of 2,3-diphosphoglycerate (Valeri et al. Vox Sang. 1971) and increased rigidity (Card RT et al. Br J Haemat. 1983). Tetrameric (human) Hb extravasates through the endothelium, binding with abluminal NO, leading to unopposed vaso-constriction (Gould et al. World J Surg. 1996).

Experimental data show that optic nerve pO₂ rises as a consequence of hemodilution, a state of anemia, where euvolemia is strictly maintained (Kimberly AN et al. Arch Clin Exp Ophthalmol. 1996).

We caution our colleagues reviewing this data to consider the current publications as insufficient and poorly conducted for the purpose of improving patient safety.

Aryeh Shander, M.D.
Tanuja S. Rijhwani, M.B.B.S.
Demarest, New Jersey