contrast media

• side-effects from high osmolality / viscosity (fluid shifts from different compartments)
  • vasodilatation
  • heat
  • pain
  • osmotic diuresis
  • hemodynamic changes
• pharmacokinetics
  • distribute volume into extracellular space
  • clearance by glomerular filtration and renal excretion
• physiologic reaction
  • increased plasma osmolality causes fluid shift from RBCs and pulmonary tissue leading to increased plasma volume
  • then osmolar gradient reverses with passage of contrast bolus -> pulmonary capillary endothelium leaks protein into pulm interstitium --> increased pulmonary edema
  • transient cardiovascular changes (magnitude increased with tonicity of medium)
    • increased PAP
    • increased CO with decreased peripheral/pulmonary vascular resistance
    • decreased systemic arterial pressure (variable)
  • may activate gen receptors causing side effects

© 2002, C.E. Kahn, Jr.
2002-04-18