Blog Wow: View blog

----------

22 Jun 2021, 19:36 Publicly Viewable

System	Major effect
Cardiovascular	These drugsdecrease arterial blood pressure. Enflurane and halothane(myocardial depressants) that decrease cardiac output, but Isoflurane, voflurane and desfluranese cause peripheral vasodilation. Nitrous oxide is less likely to lower blood pressure than are other inhaled anaesthetics. Inhaled anaesthetics supress myocardial function but nitrous oxide does least. Halothane, and to a lesser degree isoflurane, may sensitize the myocardium to the arrhythmogenic effects of catecholamines. Cardiac output (CO) is reduced with increasing concentrations of inhaled anaesthetics. In healthy individuals, this reduction in co is partially compensated by an increase in heart rate.
Central nervous system	Decrease brain metabolic rate. They reduce vascular resistance and thus increase cerebral blood flow. This can lead to an increased intracranial pressure.
Renal	Blood flow to the kidney is decreased by most inhaled agents.
Hepatic	Blood flow to the liver is decreased by most inhaled agents.
Uterus	Inhibitory effects on the contractility of the human uterus

Postoperative hepatitis has occurred (rarely) after halothane anaesthesia in patients experiencing hypovolemic shock or other severe stress.
The mechanism of hepatotoxicity is unclear but may involve the formation of reactive metabolites that cause direct toxicity or initiate immune-mediated responses.
Fluoride released by the metabolism of methoxyflurane (and possibly enflurane and sevoflurane) may cause renal insufficiency after prolonged anaesthesia.
Prolonged exposure to nitrous oxide decreases methionine synthase activity and may lead to megaloblastic anaemia. Susceptible patients may develop malignant hyperthermia when anaesthetics are used together with neuromuscular blockers (especially succinylcholine).
This rare condition is thought in some cases to be due to mutations in the gene loci corresponding to the ryanodine receptor (RyR1).
Other chromosomal loci for malignant hyperthermia include mutant alleles of the gene-encoding
skeletal muscle L-type calcium channels.
The uncontrolled release of calcium by the sarcoplasmic reticulum of skeletal muscle
leads to muscle spasm, hyperthermia, and autonomic lability.
Dantrolene is indicated for the treatment of this life-threatening condition, with supportive management.

Give classification of the LA based on the chemical characteristics. Also indicate the relative duration of action of every drug.