Anesthesia Pharmacology and Medication Management
Dose = concentration × volume
Anesthesia technicians manage the arithmetic of drug safety more than receptor pharmacology. Master the conversions: 1% = 10 mg/mL, 0.1% = 1 mg/mL, 1:1000 epinephrine = 1 mg/mL, 1:100,000 = 10 mcg/mL. Read the label twice - both the total milligrams and the volume matter - and expect look-alike/sound-alike pairs to drive error questions. Controlled substances require witnessed waste and accurate documentation of every milliliter.
Treat MAC values as benchmarks, not predictions: nitrous oxide ~104%, desflurane ~6.6%, sevoflurane ~1.8–2%, isoflurane ~1.15%. MAC decreases with opioids, propofol, hypothermia, and age; it increases in children and hyperthermia.
Know reversal and rescue doses well enough to spot a wrong order: neostigmine 0.03–0.07 mg/kg (max about 5 mg) with glycopyrrolate 0.2 mg per 1 mg of neostigmine; sugammadex 2 mg/kg at a TOF count of 2, 4 mg/kg at a post-tetanic count of 1–2, and 16 mg/kg for immediate rescue after rocuronium. Local anesthetic ceilings: lidocaine 4.5 mg/kg plain (7 mg/kg with epinephrine) and bupivacaine about 2.5–3 mg/kg. LAST treatment is 20% lipid emulsion 1.5 mL/kg bolus followed by 0.25 mL/kg/min.
Worked example: neostigmine 0.05 mg/kg for 70 kg = 3.5 mg, paired with glycopyrrolate 0.7 mg. If the vial is 0.5 mg/mL, that is 7 mL.
Trap: confusing mg/kg with mL/kg, and drawing up a high-alert drug without a second check.