- Email: [email protected]
CLINICAL EXPERIENCES WITH CT 1341
CLINICAL EXPERIENCES WITH CT 1341 J.E. Stock, B.Vet. Med., M.R.C.V.S. 35 Harrington Road, Brighton
The clinical trial of any agent used in anaesthesia is most important, and quite clearly the most revealing. At the risk of stating the obvious, anaesthesia is a dynamic state and surgical stress is the only sure fire way of finding an agents true worth. I find demonstrations of ({Anaesthesia))and recovery without any surgery particularly irritating, probably because I am a clinician, and in the long run probably sterile scientifically.
Administration Intravenous use 1. As easy as any other agent. 2.' No pain associated. 3. No vascular reaction noted one week laterl. 4. No other untoward reaction. 5: No reaction if leak back occurred. Intramuscular use 1. Large volume to handle.
2. Little or no pain to agent. 3. Surprisingly little or no response to actual volume. 4. One cat did not succumb to drug at .all ? hyper active liver or enzyme induction,' although anaesthetised on another occasion satisfactorily. 5. No clinical reaction at injection site. 6. For vicious animals extremely useful. 7. Dosage control difficult with intramuscular use. 8. Finesse of intravenous injection preferred. 9. With I/V use much less of total drug used. Financial saving and ? less stress on animals detoxifying mechanism.
Induction Intravenous Smooth pleasant for animal and handlers. Much less reduction in rate and volume of respiration than say thiopentone in equipotent doses. Induction achieved in 10-15 seconds.
'
Now tealised 10 be a problem of placing injection between rnus-cks.
46
Intramuscular Takes longer than intravenous - even then very rapid (7-10 minutes). Preferred by nursing staff for routine anaesthesia of very difficult animals. Some animals became very hyperactive before losing consciousness. Effect The state of the animal resembled a very well administered barbiturateanaesthesia without a sluggish respiratory pattern No animal showed vaso-vagal collapse which does in many hands sometimes occur with intravenous barbiturates Combination with succinyl choline lntubation as suggested by manufacturers at initial consultations with them was found virtually imposstble even with a local spray on the larynx Subsequently i f intubation was indicated, a constant depolarising muscle relaxant was used intravenously The return to spontaneous respiration was considered more rapid than with the currently available barbiturates
Analgesia On its own CT 1341 in low to medium doses did not obtund severe pain or traction on viscera and in these cases the anaesthetic had to be supplemented with either nitrous oxide, bichlorethylene or ether. In high doses this was not necessary but clearly this distracts from the safety margin, which admittedly is still very good at high doses. Nevertheless, I did prefer initially with 32-42 cats to keep the dosage as low as possible. It is after all not the function of the clinical trialist to establish the L.D. 50. I must state at this point that I am probably biased against the all in one anaesthetic because I personally believe that this should not be the aim of the anaesthetist nor do I think that it is technically possible in my professional lifetime. It also strikes against the triad principle of anaesthesia in which I like to feel at the centre adjusting the points of the triangle as circumstances demand. Recovery 25 minutes to 1 hour average depending on dosage. When recovered they were clear headed and mentally alert, with no hangover as sometimes occurs with barbiturates. Obviously sleep time was extended in a number of our cases as we were using premedicants. Low dosage muscle relaxant combinations resulted in shorter recoveries of 25 minutes.
Side-effects a) Urination - most common finding. e) Salivation - abolished with atropine sulphate. b) Defaecation - next common. f 1 Hyperaesthesia. c) Muscle tremor - not troublesome. 9) Oedema of feet - probably due to the solvent d) Paddling - one or two. Cremophor. A point to remember - when looking for side-effects one is almost bound to find some. Examination of other anaesthetics reveal all these effects listed in varying amounts. In any case, no side-effect was considered of any importance 47
Conclusion The safety margin is excellent and as a final comment, the agent was used in two cats with icterus with no untoward effectson recovery times whatever. A revolutionary class of agents likely to supercede barbiturates - I was glad and proud to be allowed to use such an agent.
48
The clinical trial of any agent used in anaesthesia is most important, and quite clearly the most revealing. At the risk of stating the obvious, anaesthesia is a dynamic state and surgical stress is the only sure fire way of finding an agents true worth. I find demonstrations of ({Anaesthesia))and recovery without any surgery particularly irritating, probably because I am a clinician, and in the long run probably sterile scientifically.
Administration Intravenous use 1. As easy as any other agent. 2.' No pain associated. 3. No vascular reaction noted one week laterl. 4. No other untoward reaction. 5: No reaction if leak back occurred. Intramuscular use 1. Large volume to handle.
2. Little or no pain to agent. 3. Surprisingly little or no response to actual volume. 4. One cat did not succumb to drug at .all ? hyper active liver or enzyme induction,' although anaesthetised on another occasion satisfactorily. 5. No clinical reaction at injection site. 6. For vicious animals extremely useful. 7. Dosage control difficult with intramuscular use. 8. Finesse of intravenous injection preferred. 9. With I/V use much less of total drug used. Financial saving and ? less stress on animals detoxifying mechanism.
Induction Intravenous Smooth pleasant for animal and handlers. Much less reduction in rate and volume of respiration than say thiopentone in equipotent doses. Induction achieved in 10-15 seconds.
'
Now tealised 10 be a problem of placing injection between rnus-cks.
46
Intramuscular Takes longer than intravenous - even then very rapid (7-10 minutes). Preferred by nursing staff for routine anaesthesia of very difficult animals. Some animals became very hyperactive before losing consciousness. Effect The state of the animal resembled a very well administered barbiturateanaesthesia without a sluggish respiratory pattern No animal showed vaso-vagal collapse which does in many hands sometimes occur with intravenous barbiturates Combination with succinyl choline lntubation as suggested by manufacturers at initial consultations with them was found virtually imposstble even with a local spray on the larynx Subsequently i f intubation was indicated, a constant depolarising muscle relaxant was used intravenously The return to spontaneous respiration was considered more rapid than with the currently available barbiturates
Analgesia On its own CT 1341 in low to medium doses did not obtund severe pain or traction on viscera and in these cases the anaesthetic had to be supplemented with either nitrous oxide, bichlorethylene or ether. In high doses this was not necessary but clearly this distracts from the safety margin, which admittedly is still very good at high doses. Nevertheless, I did prefer initially with 32-42 cats to keep the dosage as low as possible. It is after all not the function of the clinical trialist to establish the L.D. 50. I must state at this point that I am probably biased against the all in one anaesthetic because I personally believe that this should not be the aim of the anaesthetist nor do I think that it is technically possible in my professional lifetime. It also strikes against the triad principle of anaesthesia in which I like to feel at the centre adjusting the points of the triangle as circumstances demand. Recovery 25 minutes to 1 hour average depending on dosage. When recovered they were clear headed and mentally alert, with no hangover as sometimes occurs with barbiturates. Obviously sleep time was extended in a number of our cases as we were using premedicants. Low dosage muscle relaxant combinations resulted in shorter recoveries of 25 minutes.
Side-effects a) Urination - most common finding. e) Salivation - abolished with atropine sulphate. b) Defaecation - next common. f 1 Hyperaesthesia. c) Muscle tremor - not troublesome. 9) Oedema of feet - probably due to the solvent d) Paddling - one or two. Cremophor. A point to remember - when looking for side-effects one is almost bound to find some. Examination of other anaesthetics reveal all these effects listed in varying amounts. In any case, no side-effect was considered of any importance 47
Conclusion The safety margin is excellent and as a final comment, the agent was used in two cats with icterus with no untoward effectson recovery times whatever. A revolutionary class of agents likely to supercede barbiturates - I was glad and proud to be allowed to use such an agent.
48