Halothane is a widely used inhalational agent. Physical Properties of Halothane : It is colorless liquid, volatile anesthetic. Pleasant to smell so excellent for induction in children. Stored in amber colored bottles and contains thymol 0.01% as preservative (to prevent decomposition by light). Non inflammable, non explosive. Nonirritant, so induction is very smooth. Boiling point
As with other volatile agents desflurane depresses the respiratory system. Desflurane respiratory effects are quite different. There is a dose-dependent decrease in tidal volume, decreased minute volume and CO2 retention, and an increase in respiratory rate. The ventilatory response to CO2 is reduced. One of the desflurane respiratory effects is that, the desflurane is extremely
There are several disadvantages of disadvantages of carbon dioxide : • High concentration causes narcosis. • It increases the cerebral blood flow and intracranial pressure. • It stimulates sympathetic nervous system, which may be dangerous in some patients already having systemic hypertension or myocardial ischaemia. • It sensitizes myocardium to externally administered catecholamines. • It
The anesthesiologist should know that the essential element of an “anesthetic” for an Awake Craniotomy Anesthesia is the surgeon’s local anesthetic technique. Craniotomy is required for removal of space occupying lesions, intracranial vascular pathologies and for drainage of extradural or intradural haematoma. Most important postoperative considerations are regulation of patient’s ICP status, maintenance of cerebral
Excess Oxygen can cause pulmonary oxygen toxicity which results in a lot of damage to the body tissues. To summarize briefly, the excess oxygen can cause, pulmonary toxicity, Acute respiratory distress syndrome, rertolental fibroplasia, convulsions and Paul burt effect. Here we will be dicussing the mechanisms of these tissue injuries that occur with use of excess oxygen. The following the changes
The reduced cerebrovascular resistance at the site of Arteriovenous Malformations AVMs lead to an increase in blood flow to this area and the formation of a lower resistance shunt along with peri-infarction oedema. They usually represent a high-flow and low-resistance shunts with systemic arterial pressure more than the vascular intramural pressure ; so, rupture does
The Respiratory Tract anatomy is very essential for understanding the functions of a lung and hence should be known to every doctor. The Respiratory Tract anatomy starts with the oropharynx and the nasopharynx which are spaces in the mouth and the nose that act as conduit for the respiratory gases. At carina trachea divides into
Metabolism of volatile anesthetics is discussed here. Once thought to be chemically inert, inhalation agents, especially the older ones, undergo significant metabolism, bio-transformation and breakdown to potentially toxic intermediates. This process is affected by age, disease, drug interaction and genetics. Inhalation agents are administered in great excess of the amount metabolized unlike other drugs. For
Desflurane mechanism of action is briefly studied. There is a dose-dependent suppression of EEG, at MAC greater than 1.66 the LEG becomes isoelectric. There is no evidence of epileptiform activity. It decreases the amplitude of somatosensory evoked potentials. There is a dose-dependent decrease in cerebral metabolism and cerebral vasodilatation. Cerebral autoregulation is impaired similar to
Desflurane undergoes very little desflurane metabolism because of low blood/gas and low blood/tissue solubility. However, 0.02% is metabolized during desflurane metabolism with the production of trifluoroacetic acid which may interact with hepatic proteins and induce an immune response in susceptible patients. Previous exposure to halothane may produce antibodies. In desflurane metabolism , the elimination is almost exclusively by
