Paranasal sinus cyst as a cause of stridor in a standardbred colt.

Sinus cysts are epithelium-lined, fluid-filled cavities that can occur in the paranasal sinuses of horses. Extensive damage to the permanent tooth buds was a significant feature in this case. The sequellae of these abnormalities, although not apparent at the time of presentation, remain an important consideration for prognosis.

Gravel impaction in a 2-year-old Morgan gelding.

An unusual case of impaction colic caused by the ingestion of large quantities of gravel. The clinical presentation, surgical findings, and outcome are described.

Fatal air embolism during anesthesia for laparoscopy in a dog.

A 13-year-old dog went into cardiopulmonary arrest after insufflation of the abdominal cavity with nitrogen for laparoscopy. Resuscitation was unsuccessful. Necropsy findings included a punctured spleen and confirmed the development of air embolism.

Percutaneous transtracheal ventilation and morphometric measurements of cervical structures in swine.

Fifteen swine cadavers were examined to determine a quick, reliable means of locating the level of the cricothyroid ligament from consistently palpable structures in the head and neck area. From calculations of measurements made on these cadavers, it was discovered that when a 21-43 kg pig was placed in a standard position, the measured length (L) from the angle of the mandible to the manubrium sterni multiplied by a factor of 0.48 equals the parameter Z [L (0.48) = Z]. Z was measured, beginning at the manubrium sterni, along the ventral midline. The endpoint of Z was at the level of the cricothyroid ligament. A catheter inserted at this point through the ligament into the airway provides a means of transtracheal ventilation. This method of ventilation can be used in emergencies to avoid a tracheostomy or as an alternative to endotracheal ventilation. This method was applied successfully to four anesthetized pigs as determined by a series of arterial blood gas samples.

Cesarean section. Anesthetic management and surgical technique.

Cesarean section can be an elective procedure but more often it is an emergency procedure that is made necessary because of dystocia. A successful outcome for both the maternal and fetal patients is primarily dependent on a thorough understanding of the physiologic alterations during normal and abnormal pregnancy and parturition. A complete history and physical examination are necessary for assessment of the dam and planning of fluid therapy and anesthetic technique. Timely coordination of presurgical preparation, anesthesia, and the surgical procedure is crucial. Because little documentation exists to prove that any one anesthetic protocol is best, this article will stress the basic principles of obstetrical anesthesia and patient management.

Cardiopulmonary effects of a xylazine and ketamine combination in pigs.

The carotid and pulmonary arteries were catheterised in six pigs anaesthetised with thiopentone sodium and halothane. A minimum of five days was allowed to elapse before the investigation. The carotid artery pressure, pulmonary artery pressure, cardiac output, arterial pH, PO2, PCO2, plasma glucose and lactate were measured before and after intravenous injection of xylazine (1 mg kg-1) and ketamine 10 mg kg-1). Complete analgesia was produced for 10 minutes in all pigs but by 25 minutes all animals responded to a painful stimulus. The cardiac output and arterial PO2 were significantly decreased for 30 minutes and 10 minutes, respectively. The total vascular resistance was significantly increased. No statistically significant changes occurred in the other variables measured.

Effect of acetazolamide in blood acid-base and electrolyte values in dogs.

The effects of acetazolamide administration on arterial blood acid-base equilibrium and electrolyte concentrations were evaluated in 13 clinical patients and in a 4-week experiment in 6 conditioned mixed-breed dogs. Findings included persistent acidemia characterized by hyperchloremic metabolic acidosis, elevated partial pressure of oxygen, and mild depletion of potassium. Changes in the partial pressure of carbon dioxide were variable, and there was no change in plasma sodium concentration or osmolality. Measured disturbances were apparent within 12 hours of the commencement of acetazolamide administration, peaked at between 1.5 and 5.0 days, and thereafter stabilized. Abnormalities were restored to normal within 1.5 days following termination of drug administration.

Cardiopulmonary resuscitation in the nonhuman primate.

Seventeen adult male Cynamolgus monkeys were subjected to potassium chloride-induced cardiopulmonary arrests of 10 to 12 minutes. Pupils became dilated and fixed at a mean interval of 30 +/- 11 seconds, and the electroencephalogram became isoelectric at a mean interval of 34 +/- 13 seconds. The monkeys were resuscitated by means of oxygen, external cardiac message, epinephrine, calcium, and bicarbonate. The mean time required to resuscitate the monkeys was 140 +/- 70 seconds. After resuscitation, the monkeys were kept in an intensive care unit. Pupillary responsiveness and electroencephalographic activity were slow to return, with mean intervals of 90 +/- 85 and 108 +/- 36 minutes, respectively. Although all 17 monkeys were resuscitated, only 9 survived 96 hours or more. Of the 9 survivors, 2 appeared neurologically normal, 3 were moderately impaired, and 4 were severely impaired.

Dose dependency of the post-insult protective effect of pentobarbital in the canine experimental stroke model.

In a canine stroke model, dose dependent protection by postocclusion pentobarbital was suggested from 10--40 mg/kg. In 28 dogs investigated (10 from a previous study) a distinct, significant reduction in right cerebral hemisphere infarction occurred in animals given 15--20 mg/kg pentobarbital intramuscularly 1 hour postocclusion. Increased dosages did not alter statistically the infarct size and 2 dogs at the 50 mg/kg and 80 mg/kg levels died of barbiturate-induced respiratory failure.