Unusually High Propofol and Sevoflurane Requirements in a Patient with a Red Beard Phenotype: Bridging Clinical Practice and Literature

Abstract

Background: The association between the red hair phenotype (homozygous MC1R mutations) and increased volatile anesthetic requirements is well-documented. However, current literature suggests that propofol requirements remain unaltered. Furthermore, the “red beard” phenotype in males with different scalp hair colors, representing a heterozygous MC1R state, is rarely explored in anesthesia research. We report a unique case of a Caucasian patient with a red beard who exhibited significant resistance to conventional induction doses of propofol. Case presentation: A 32-year-old healthy Caucasian male (ASA II, BMI 25.35 kg/m²) presenting with a bright red beard and blonde hair was scheduled for a bilateral varicocelectomy. Pre-anesthetic evaluation indicated a high risk for a difficult airway (Mallampati class 3, upper lip bite test class 3, and a DIFFMASK score of 6 points). Anesthetic induction was initiated with a high conventional dose of propofol (3 mg/kg) combined with 15 mcg of sufentanil. Following initial drug administration, the patient demonstrated poor mouth opening, persistent airway reflexes, and inadequate pharyngeal relaxation, making laryngeal mask airway insertion unfeasible. Propofol was further titrated to a total dose of approximately 4 mg/kg, combined with 50 mg of rocuronium, which successfully achieved complete muscle relaxation and smooth airway control. Anesthetic maintenance required a 20% increase in sevoflurane minimum alveolar concentration. Hemodynamics remained exceptionally stable throughout the surgery without meaningful hypotension or bradycardia. The patient emerged promptly and uneventfully. Conclusion: This case demonstrates that a red beard phenotype, reflecting a heterozygous MC1R mutation, can serve as a visible clinical surrogate marker predicting cross-resistance to standard doses of both volatile and intravenous anesthetics. Clinical anesthesiologists should prioritize individualized, physiological response-driven dose titration over strict weight-based formulas in this specific patient population.