Ether is still very widely used in many Developing countries like India.
First public demonstration of ether was given by W.T.G. Morton on I6thOctober 1846 for the removal of jaw tumor.
Physical Properties of Ether :
• It is pungent smelling liquid decomposes in presence of light, air and heat so stored in amber colored bottles.
• Highly inflammable and explosive.
• Highly irritant vapor.
Anesthetic Properties of Ether :
• Induction is very slow (blood gas coefficient 12.0) and very unpleasant (pungent smelling) sot here are very high chances of laryngospasm with ether induction. -
• Potency is moderate (MAC 1.92)
• Very good analgesic.
• Usually required-concentration is 5 to 15%.
• Very good muscle relaxant.
• Delivery method: By open drop; EMO inhaler, copper kettle vaporizer, Oxford miniature vaporizers.
Systemic Effects of Ether :
Cardiovascular system: It does not depresses myocardium rather it stimulates sympathetic system causing tachycardia and hypertension.
Baroreceptor reflex is preserved with ether so ether can be used safely in patients with shock. Respiratory system: It does not depress respiration rather respiration is stimulated. Only at very high doses respiration is inhibited.
Ventilatory responses to hypoxia and hypercarbia are preserved.
Bronchial muscles: It is potent bronchodilator. Ciliary activity: It is the only inhalational agent
which preserves diary activity.
TracheobronchiaI secretions: Are markedly increased, so premedication with atropine is necessary.
GIT: Highest incidence of nausea and vomiting among inhalational agents.
Hepatic and renal functions: They are well preserved.
Cerebral: Intracranial tension is increased with ether. Uterus: Uterine relaxation may be seen in deeper planes.
Uteroplacental barrier: It readily crosses placenta and can cause respiratory depression in newborn. Metabolic: It releases catecholamines and can cause hyperglycemia. So should not be used in diabetics.
Metabolism of Ether :
Metabolized to alcohol, acetaldehyde and acetic acid. These products are non toxic.
Advantages of Ether :
1. It is very cheap (almost 70 times cheaper than halothane and 150 times cheaper than isoflurane). So it is still used in remote parts of our country.
2 Can be used as sole agent for anesthesia as it has all properties of anesthesia viz, narcosis, analgesia, muscle relaxation or in other words it is the only complete anesthetic agent.
3. Very safe: Does not produce any cardiac or respiratory depression, so can be used at remote places (like wars and disasters) and with less experienced hands.
4. Requires very less instrumentation for delivery (even can be given by open drop method).
5. Does not produce any toxic metabolite.
6. It can be given by using air as carrier gas by air ether apparatus i.e., even oxygen cylinders may not be required.
Disadvantages of Ether :
1. High inflammable and high explosive. There have been death reports following burns by ether.
2. Induction is very irritating and unpleasant and can induce severe laryngospasm.
3. Tracheobronchial secretions are increased.
4. Recovery is delayed.
5. Very high incidence of nausea and vomiting, therefore recovery and postoperative period is unpleasant.