Anaesthetic doses of various drugs in an obese patient is very confusing. Many factors change the pharmacokinetics and pharmacodynamics of these drugs. Increased cardiac output definitely affects the early part of Pk pertaining to drug distribution. Decreased blood flow to fat explains why lipophilic drugs do not have increased volume of distribution despite huge increase in fat mass. Distribution of hydrophilic drugs is increased as per the ECF which is incidentally high in fat people. There's always increase in glomerular filtration. Non alcoholic steatohepatitis NASH is very frequently seen in obese patient. Let me describe the exact doses.
1. Thiopentone Induction as per Lean body weight (LBW) but maintenance as per the Total Body weight ( TBW). 2. Propofol same. 3. Fentanyl as per the lean body weight. 4. Scoline as per total body weight and non depolarizing muscle relaxants as per…
