The case for low gas flows.

When nitrous oxide is not used, there are no clinically significant, valid reasons for not using low gas flows. There are many clinically significant, valid reasons for using low flows.     

Use of pneumocystoplasty for overinflation of the swim bladder in a goldfish

A Ryukin goldfish was evaluated because of a 6-month history of progressive abdominal distention and positive buoyancy. Overinflation of the swim bladder was diagnosed, and the fish was anesthetized with tricaine methanesulfonate. Archimedes' principle was used to determine the volume of swim bladder that was removed surgically. The caudal swim bladder was exteriorized through an abdominal incision and 2 surgical clips were placed across it to limit its size. After surgery, the fish remained in a state of negative buoyancy in sternal and lateral recumbency on the bottom of the tank. Sutures were removed 15 days after surgery, but the fish died 24 days after surgery. A full necropsy could not be performed because of autolysis of the tissues, but the surgical clips and the swim bladder appeared unremarkable. Pneumocystoplasty may be a viable treatment for this condition.     

Use of acupuncture for the treatment of chronic back pain in horses: stimulation of acupuncture points with saline solution injections

Fifteen horses that could not train or perform their sport at an acceptable level because of chronic back pain of 2 to 24 months' duration, and that did not obtain lasting improvement from other previous treatments, were treated with acupuncture. The treatments consisted of injection of 1 ml of sterile saline (0.9% NaCl) solution, with no preservatives, at 9 acupuncture points. The horses were treated once a week for a mean of 9 treatments. The mean number of treatments before obvious improvement was 4. After treatment, 13 of the 15 horses had apparent alleviation of their signs of pain and could train and compete. Six to 12 months after their last treatment, 2 horses had been removed from competition; one had sustained a fracture and the other had died. The remaining 11 of the original 13 that competed after treatment were still competing.     

Quantitative anesthesia.

Quantitative anesthesia is delivering anesthetic and oxygen in known quantities, the dosage based on calculations for their uptake. The uptake is not linearly related to body weight but is linearly related to body weight raised to a power. The dosage of inhaled anesthetics is calculated by the method of Lowe. The oxygen consumption and cardiac output are estimated by formulas that relate physiologic functions to the body weight in kilograms, raised to a power.     

Fresh gas flows with the circle system.

If, when using a circle system, the flow of all inhaled gases exactly equals the uptake of all these gases by the patient, the circle system is called a closed circle system. If the fresh gas flows are higher than the uptake of the gases by the body, the circle system is a semiclosed circle system. The mechanical status of the pop-off valve; i.e., open or closed, has nothing to do with the definition of whether the circle is closed or semiclosed.     

Anatomy of the spinal cord and how the spinal cord is affected by local anesthetics and other drugs.

The spinal cord can be affected by several categories of drugs: local anesthetics, opiate agonist, alpha 2 adrenergic agonists, and ketamine. The mechanism of action, side effects, and usefulness of these injections vary with the type of drug used.