Goldilocks and Propofol Dosage in Older Adults: Too Much, Too Little, or Just Right?

Michael J. Devinney MD, PhD; Miles Berger MD, PhD

Disclosures

J Am Geriatr Soc. 2021;69(8):2106-2109. 

In This Article

Abstract and Introduction

Introduction

"The only difference between a drug and a poison lies in the dose" wrote the Swiss physician and alchemist Paracelsus (1498–1538).[1] Nearly half a millennium later, this principle remains highly applicable to the practice of geriatric anesthesiology, particularly at the induction of general anesthesia with propofol in older adults (Figure 1). The induction of general anesthesia aims to rapidly transform an awake, conscious patient to one who is amnestic, unconscious, and ready to undergo tracheal intubation without pain, movement, or increased blood pressure or heart rate (i.e., hemodynamic derangements). Yet, many commonly used anesthetic induction agents such as propofol can cause significant and even life-threatening reductions in blood pressure, respiratory depression, and other adverse events. The propofol dose ranges that will cause both beneficial and detrimental effects decline with increasing age, which has led the FDA to issue the recommendation that the induction dose of propofol should be reduced from 2–2.5 mg/kg to 1–1.5 mg/kg in older adults.[2] Yet, the question remains to what extent this recommendation is being followed: i.e., how much propofol are older Americans receiving for anesthesia induction? This question is addressed by a thorough study in this issue of JAGS by Schonberger and colleagues,[3] which includes propofol induction dose data from over 350,000 older Americans at 36 institutions from 2014 to 2018.

Figure 1.

Weighing the propofol dosage for use as a medicine versus as a poison

Schonberger and colleagues show that the majority of older adults received propofol induction doses above the recommended FDA range for older adults of 1–1.5 mg/kg. They also show that the percentage of older adults receiving doses above the 1.5 mg/kg FDA upper limit decreases with age, from ~74% in patients age 65–69 to ~46% in patients aged 80 and older. Encouragingly, propofol doses >1.5 mg/kg also occurred at lower rates in patients presumed to be at higher risk for adverse outcomes from excessive dosage, i.e., in those with coronary disease, more severe frailty, or chronic kidney disease. These data fit well with prior reports from multiple centers across the United States and Europe showing that the majority of older adults also likely received excessive inhaled anesthetic dosage to maintain general anesthesia during surgery, i.e., older adults received relatively higher age-adjusted inhaled anesthetic doses than young and middle aged adults.[4–7] Together, these data suggest that older American and European patients are likely receiving larger doses than necessary for both the induction and maintenance of general anesthesia.

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