The goals (3) of anaesthetic management are
- Myocardial depression should be avoided
- Normovolemia is maintained
- To avoid overdose of drugs during induction as the circulation time is slow.
- Ventricular afterload is avoided
- Avoid sudden hypotension when regional anaesthesia is the choice
- Induction by midazolam/nitrous oxide/ vecuronium /isoflurane for GA
- Graded epidural anaesthesia with sedation using midazolam.The advantages are adequate post operative analgesia and less hemodynamic alteration.The changes in preload and afterload produced by epidural anesthesia mimic the pharmacological goals of treatment.(3) Here an anaesthetic level upto T4 is required and a well relaxed abdominal muscles are preferred.To achieve this goal the dosage of local anaesthetic requirement would be high which may precipitate sudden change in hemodynamics and the treatment of hypotension with ephedrine further worsens the CVS status.Phenylephrine if used to treat hypotension may cause increase in afterload which is detrimental.Hence the decision to administer GA.
1)Yamaguchi S, Wake K, Mishio M, et al. Anesthetic management of a patient with dilated cardiomyopathy under total intravenous venous anaesthesia with propofol and ketamine combined with continuous epidural analgesia. Masui 1999;48: 1232-34.
2 WILLIAM G, VALENTIN FUSTER: Idiopathic dilated Cardiomyopathy. New England Journal of Medicine; 331:1564-75, 1994.
3. ROBERT STOELTING K, STEPHEN F: Anesthesia And Co-Existing Disease, 4th Edition Lippincott-Raven; Ch. 7:117-120.