Complex sentence: As such, the practice of anesthesia in the US may be delivered by either a nurse anesthetist or an anesthesiologist, although the vast majority of anesthetics are delivered currently are under the ACT model or by a sole anesthesiologist.
Split into simpler sentences: As such, the practice of anesthesia in the US may be delivered by either a nurse anesthetist or an anesthesiologist. However, the vast majority of anesthetics delivered today are under the ACT model or by a sole anesthesiologist.