938. Close-circuit anaesthesia is efficient and economical

Two days ago, I met a senior vet. He was reiterating the way the younger vets now use gaseous anaesthesia with a very high flow rate of oxygen, using an open circuit, thereby wasting a lot of anaesthesia and Oxygen. The younger vets would not accept his method of using closed circuit. This was also a method I used. Now I used the semi-open method.

"Take it easy," I said. "The younger vets have their mindsets so much different from us. Their vet professors have had trained them and they did it the professors' way. After all, vet professors don't have to account for the bottom-line. Neither do the younger employee vets. So, they don't worry since they don't have to pay to replace fast-consumed isoflurane which is extremely expensive.

I used oxygen flow rate of 0.5 in a closed circuit, while the younger vets used 2 litres/min. In a long surgery of 2 hours, the volume of oxygen and isoflurane gas used is considerable and costly.

"Maybe the younger vet is afraid that in a closed circuit, the isoflurane level increses and then kills the dog," I said.

"No," the senior vet said. "Just switch off the oxygen or lower the flow. The 2% maintenance isoflurane in a closed circuit may go down to 1.8% but will not increase."

"Maybe the younger vet is afraid that the carbon dioxide will accumulate inside the closed circuit, killing the patient. I know, soda lime absorbs the CO2, but the younger vet may be worried."

"Yes, the soda lime removes the CO2. So, there is no worry. I had long discussions with a human anaesthestist on the closed circuit and that's the most economical way. Don't use nitrous oxide though as some dogs do die."

"But young vets who are employees don't have to pay for any amount of isoflurane they use. So, a high oxygen flow rate (over 2 litres/min) use up a lot of isoflurane in an open circuit - so what? They don't need to pay. So, they can't be bothered," I said.

This senior vet is irked by inefficiency and unnecessary wastage but the younger vet refused to adopt the closed circuit. Maybe, they have their reasons. I have not talked to them.

Each vet has his own peculiarities. This senior vet uses electro-surgical coagulation in the castration of dogs. I don't. Seldom do other vets. "I wonder how I manage without it?" I asked one young vet as this senior vet uses it for all surgeries except spay.