|Year : 1982 | Volume
| Issue : 4 | Page : 237-239
Neurolept analgesic and dissociative anaesthesia in ocular surgery
RK Mishra, KP Chansoria
Dept. of Ophthalmology and Anaesthesiology Medical College, Jabalpur, India
R K Mishra
Dept. of Ophthalmology Medical College Jabalpur, (M.P.)
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mishra R K, Chansoria K P. Neurolept analgesic and dissociative anaesthesia in ocular surgery. Indian J Ophthalmol 1982;30:237-9
|How to cite this URL:|
Mishra R K, Chansoria K P. Neurolept analgesic and dissociative anaesthesia in ocular surgery. Indian J Ophthalmol [serial online] 1982 [cited 2020 Aug 14];30:237-9. Available from: http://www.ijo.in/text.asp?1982/30/4/237/29437
Most of the ocular surgery is satisfactorily completed under the usual surface anaesthesia and nerve block. This makes the ophthalmic surgeon independent of the anaesthetist. However, there are occasions when general anaesthesia is required as in paediatric patients or where prolonged surgery is essential. In such situations one has to turn to conventional general anaesthetics. These substances provide good anaesthesia for many types of general surgical work but the ophthalmologists have special problems, holding of breath, rise of abdominal or thoracic pressure when the patient slides back to lighter plan and the emergence from anaesthesia are frequently associated with nausia vomiting and restlessness. These are particularly harmful in intraocular operation cases. In view of these problems we have tried two newer group of drugs namely Ketamin as a dissociative anaesthesia and Droperidol-Fentanyl combination as neurolept analgesia. A number of papers have appeared in American and continental journals but so far these drugs have not received much attention of Indian Ophthalmologists.
| DISSOCIATivE ANAESTHESIA|| |
It is a very interesting state of mind with complete unconsciousness, prolonged analgesia and intact protractive reflexes. By expression on the patients face it appears that he is conscious and watching but actually the patient is completely unconscious and subsequently remember nothing.
Ketamin intra muscular or intra venous produces profound anaethesia and strong analgesia by dissociating brain and the association pathway. Ketamin hydrochloride is sold under trade name of Ketalar. It is non barbiturate anaesthetic. When given in doses 9-13 mg/kg wt. intramuscularly it produces surgical anaesthesia in 10 minutes lasting about 20 minutes which can be prolonged by I.M. or I.V. repeats.
With this drug cough and deglutition reflexes are intact. The patient has a quick and peaceful emergence. There is no struggle, vomiting, nausea or pain. Preoperative starvation is not essential though it helps. The drug has its own draw backs. Rise of B.P' rise of intra ocular tension, micronystagmuse twitching of lids and fibrilation in muscles ar, its shortcomings.
| Neurolept analgesia|| |
Neurolept analgesia was introduced in 1959. Neurolept state is a combined effect of psycomotor sedation by Droperidol and a very strong analgesia by Fentanyl. Neurolept analgesia differs significantly from general anaesthesia in mechanism and in appearance. The function of the cortex directing the perceptive and consciousactivity does not cease but the patient becomes completely insensitive in relation to the events happening with and arround him. The pain sensations along with its reflex consequences stop under the strong analgesic effects. Such a state is called state of "Mineralization" by the physiologists. In this state the hypothalmic reticular system is selectively depressed and the vital functions along with the peripheral metabolism remains unchanged. Blood pressure remains stable, pulse rate does not change and the myocardium functions within the normal capacily of the person concerned. By virtue of its "Alpha receptor blocking action", Droperi dol maintains tissue perfusion and prevents surgical shock.
During neurolept analgesia by droperidol and fentanyl LM. or IN. patient remains conscious. He can follow instructions meaningfully, remains totally unconcerned and totally pain free. Adult dose of Droperidol is 2.5 to 5 mg, I.M. or I.V. Fentanyl is given in doses of 0.05 to 0.4 mg. LM. or I.V. In children:- Droperidol is given 0.1 to 0.5mg/kg. body wt. and Fentanyl is given 0 002 mg. to 0.015 mg/kg body wt. The induction is very easy by I.V, route and can be prolonged by I.V. or I.M. route.
There is no age bar with this procedure, Elderly Patient who are considered bad anaesthetic risk tolerate in very well. The emergence is very calm and quiet. There is no struggle and no post operative nausea or vomiting. Analgesia persists for many hours so that no further analgesic is required. The intra ocular pressure is totally un-affected all through.
Children and young patients undergoing short painful interference are generally very well managed by dissociative anaesthesia by Ketamin Hcl. It does not require much of pre-operative preparation and the analgesia is perfect with protective reflexes intact. Since it raises the intra ocular pressure it is not suitable where the globe is opened or in glucoma prone cases. It is contraindicated in hypertensiveness. It does not effect the respiratory system in any way.
Neurolept analgesia in the ideal form of assistance where the ophthalmologist must seek more than what he can manage by surface anaesthesia and nerve blocks. Since the patient is not unconscious it is a good precaution to give fascial block to prevent patient inadvertant squeeing of his eyes even though there is total analgesia and tranquility. In the usual lot of senile patient with cardiovascular problems this drug combination is ideal. Not only it does not adversely effect the CVS system it actually stabilizes the system and prevents shock state by its alpha receptor blocking action.
The fact that is a respiratory depresent makes it imperative to take assistance of anaesthesiologist. It can safely be prolonged for many hours when needed.
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