title: A Retrospective Observational Study of Anesthetic Induction Dosing Practices in Female Elderly Surgical Patients: Are We Overdosing Older Patients?
abstract: Despite guidelines suggesting a 25-50 % reduction in induction doses of intravenous anesthetic agents in the elderly (≥65 years), we hypothesized that practitioners were not sufficiently correcting drug administration for age, contributing to an increased incidence of hypotension in older patients undergoing general anesthesia.
  
  
  
  We conducted a retrospective, observational study in a tertiary-care academic hospital. The study included 768 female patients undergoing gynecologic surgeries who received propofol-based induction of general anesthesia.
  
  
  
  Weight-adjusted anesthetic induction dosing, age-associated differences in dosing by ASA-PS (American Society of Anesthesiology-Physical Status), and hemodynamic outcomes between younger (18-64 years, n = 537) and older (≥65 years, n = 231) female patients were analyzed.
  
  
  
  Older patients received lower doses of propofol and midazolam than younger patients (propofol: 2.037 ± 0.783 vs 2.322 ± 0.834 mg/kg, p < 0.001; midazolam: 0.013 ± 0.014 vs 0.023 ± 0.042 mg/kg, p < 0.001). However, practitioners still consistently exceeded the FDA recommended dose (1-1.5 mg/kg) of propofol for elderly patients. There was no significant difference in the doses of fentanyl administered between the two age groups (1.343 ± 0.744 vs 1.363 ± 0.763 μg/kg, p = 0.744), and doses of fentanyl in older patients exceeded the recommended dose (0.5-1.0 μg/kg). Corresponding to observed overdosing of induction agents, older patients experienced larger decreases in post-induction blood pressure and were more likely to receive vasopressor therapy.
  
  
  
  Anesthetic induction doses of fentanyl and propofol were not sufficiently corrected in older patients in accordance with recommendations. Significantly greater frequency of post-induction hypotension occurred amongst older patients. Quality improvement efforts may lead to improved outcomes in this vulnerable population.
authors: Department of Anesthesiology and Pharmacology, Yale School of Medicine, 333 Cedar Street, TMP 3, New Haven, CT, 06510-8051, USA. shamsuddin.akhtar@yale.edu.
authors: Shamsuddin
authors: 0000-0002-1127-0538
authors: S
authors: Akhtar
authors: Department of Internal Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
authors: Joseph
authors: J
authors: Heng
authors: Yale Center for Analytical Sciences, New Haven, CT, USA.
authors: Feng
authors: F
authors: Dai
authors: Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA.
authors: Robert B
authors: RB
authors: Schonberger
authors: Departments of Anesthesiology and Internal Medicine, Yale School of Medicine, New Haven, CT, USA.
authors: Mathew M
authors: MM
authors: Burg
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000768:Anesthesia, General / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage* / Q000009:adverse effects; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage* / Q000009:adverse effects; D013509:Gynecologic Surgical Procedures; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000139:chemically induced; D008297:Male; D008874:Midazolam / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D015742:Propofol / Q000008:administration & dosage* / Q000009:adverse effects; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D008874:Midazolam; D005283:Fentanyl; D015742:Propofol