Page 13 - CASA Bulletin of Anesthesiology 2022; 9(5)

Vol. 9, No 5, 2022

A Single Syringe Multimodal Non-Opioid 6-2-2 Sedation Method

Zhuang T. Fang, MD, MSPH, FASA, Clinical Professor
David Geffen School of Medicine at UCLA, Department of Anesthesiology and
Perioperative Medicine

Monitored anesthesia care (MAC) is broadly used in patients who undergo surgical and
diagnostic procedures . However, there is no standardized method of MAC. The ASA closed
1
claims study in 2006 showed, when MAC associated complications occurred, the percentage of
permanent brain injury and death was the same as that for general anesthesia, which is about
2
40% . Over sedation has been identified as a major cause of perioperative patient morbidity and
mortality with MAC.

With their powerful analgesic effects, opioids have been used as an important part of the
balanced anesthesia technique in treating perioperative pain during GA and MAC for many
decades. However, the ongoing opioid crisis in the United States has been worsened by the
concurrent Covid-19 pandemic leading to a steady increase in drug overdoses and more than
100,000 deaths in 2021 . The economic consequences are enormous with an estimated $80
3
billion spent yearly in healthcare and treatment, lost productivity, and legal judicial costs 4
anesthesia providers have been under tremendous pressure to reduce perioperative opioid use, as
research shows 6% of patients will become chronic opioid users after minor or major surgical
procedures.

In the past decade, opioid-sparing and opioid-free anesthesia techniques have been the main
strategy and research focus for anesthesia providers battling the opioid epidemic; however, most
of the studies focused on general anesthetics (GA) and not on MAC. Unlike GA, in which
inhalational agents are an option to provide unconsciousness, immobility, and amnesia, MAC for
surgical procedures relies on intravenous agents to provide analgesia, anxiolysis, and desired
surgical conditions.

Propofol is the most common anesthetics for MAC in diagnostic procedures, but it is
inadequate for surgical procedures because of its lack of analgesia. Dexmedetomidine has been
studied extensively in the last two decades, however, its single use in surgical sedation has been
limited due to its weak analgesic effect, inadequate sedation, and high incidence of bradycardia
and hypotension . Multimodal, or balanced anesthesia, with a combination of propofol,
4
ketamine, dexmedetomidine, or benzodiazepines is a scientifically logical approach for MAC
with superior analgesic and sedative effects compared to the use of single agents . Induction is
5, 6
the most challenging phase of MAC, especially in procedures requiring blocks performed before
skin preparation and sterilization. However, during induction, it is cumbersome to administer
each drug separately, difficult to determine the dose and time interval of administration, and
arduous to measure the efficacy and quality of sedation.
In the last 19 years, the single syringe multimodal opioid-based A6-2-2 (alfentanil) and other
mixtures (fentanyl, combined alfentanil and fentanyl, etc.) have been routinely used in our
institute to provide quality MAC for patients undergoing ophthalmic surgery, comfortably and
7, 8
9
safely . In the last several years, we also developed a non-opioid KE6-2-2 mixture , which
contains 6 portions of 10 mg/ml propofol, 2 portions of 10 mg/ml ketamine, and 2 portions of 2
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