Capnography-guided Endotracheal Intubation as an Alternative to Existing Intubation Methods in Rabbits.

Rabbits provide a unique challenge for routine endotracheal intubation in clinical practice because of various distinctive anatomic and physiologic features. Many previously proposed methods for endotracheal intubation in rabbits are limited by several factors, including the needs for expensive equipment and high levels of technical expertise. We evaluated capnography for its effectiveness in assisting endotracheal intubation in rabbits. New Zealand white rabbits were divided into 3 groups of 5 animals. In the first 2 groups, mainstream (nondiverting) or sidestream (diverting) capnography (MC and SC groups, re- spectively) was used; in the third group (LS group), a laryngoscope with a size 00 Miller blade was used to guide endotracheal tube placement. Anesthesia was induced through intramuscular administration of ketamine (10 mg/kg), medetomidine (0.1 mg/kg), and midazolam (1 mg/kg) mixed in the same syringe prior to administration. Intubation time was defined from the point of opening the jaws to the completion of the first capnogram after intubation. Intubation was accomplished successfully in all animals in both capnography groups, but 2 rabbits in the laryngoscopy group could not be intubated. Intubation time was compared among groups was compared by using one-way ANOVA, and posthoc Bonferroni testing was applied to isolate significant differences between groups. The intubation time (mean ± 1 SD) was 46.4 ± 12.6 s in the MC group, 147.2 ± 44.2 s in the SC group, and 385.0 ± 114.1 in the LS group, with intubation time significantly differing among all groups. In conclusion, both mainstream and sidestream capnography-guided endotracheal intubation techniques were more effective and efficient than conventional laryngoscope-guided endotracheal intubation in rabbits. Furthermore, mainstream capnography was preferred over sidestream capnography because mainstream capnography resulted in significantly shorter intubation times.

Comparison of the ability of veterinary medical students to perform laparoscopic versus conventional open ovariectomy on live dogs.

OBJECTIVE: To compare the feasibility of training veterinary medicine students to perform laparoscopic versus conventional open ovariectomy in live dogs. DESIGN: Randomized prospective parallel-group experiment. POPULATION: 25 students completing the second year of their veterinary curriculum. PROCEDURES: Students were randomly assigned to 2 groups to receive 14 hours of specific training in either open ovariectomy (n = 13) or laparoscopic ovariectomy (12). Confidence, basic surgical skills, and basic laparoscopic skills were evaluated before and after training, prior to live surgical procedures. RESULTS: Scores related to basic surgical skills were high in both groups and did not improve with either training program. Before live animal surgeries, student confidence and basic laparoscopic skills improved after training in laparoscopic ovariectomy and were higher than after training in open ovariectomy. Surgery time was higher for the students who received training in laparoscopic ovariectomy (129 minutes; range, 84 to 143 minutes), compared with students who received training in open ovariectomy (80 minutes; range, 62 to 117 minutes). On a 55-point scoring system, ovariectomy scores were similar between students who received training in open ovariectomy (34.5; range, 16.5 to 45) and students who received training in laparoscopic ovariectomy (34.5; range, 25 to 44.5). CONCLUSIONS AND CLINICAL RELEVANCE: The training programs were effective in improving student confidence and skills in laparoscopic ovariectomy. Results of this study suggested that veterinary medical students, with assistance from an instructor, may be taught to perform laparoscopic ovariectomies with performance equivalent to that for students performing open ovariectomies.

The effect of epidural injection speed on epidural pressure and distribution of solution in anesthetized dogs.

OBJECTIVE: To determine the effect of injection speed on epidural pressure (EP), injection pressure (IP), epidural distribution (ED) of solution, and extent of sensory blockade (SB) during lumbosacral epidural anesthesia in dogs. STUDY DESIGN: Prospective experimental trial. ANIMALS: Ten healthy adult Beagle dogs weighing 8.7 ± 1.6 kg. METHODS: General anesthesia was induced with propofol administered intravenously and maintained with isoflurane. Keeping the dogs in sternal recumbency, two spinal needles connected to electrical pressure transducers were inserted into the L6-L7 and the L7-S1 intervertebral epidural spaces for EP and IP measurements, respectively. Bupivacaine 0.5% diluted in iohexol was administered epidurally to each dog via spinal needle at L7-S1 intervertebral space, at two rates of injection (1 and 2 mL minute(-1) groups), with a 1-week washout period. Epidural distribution was verified with computed tomography, and SB was evaluated after arousal by pinching the skin with a mosquito hemostatic forceps over the vertebral dermatomes. The results were analyzed according to each injection speed, using paired t- and Wilcoxon signed-rank tests. RESULTS: Mean ± SD of baseline EP and IP values were 2.1 ± 6.1 and 2.6 ± 7.1 mmHg, respectively. Significant differences were observed between 1 and 2 mL minute(-1) groups for peak EP (23.1 ± 8.5 and 35.0 ± 14.5 mmHg, p = 0.047) and peak IP (68.5 ± 10.7 and 144.7 ± 32.6 mmHg, p <0.001). However, the median (range) of the ED, 11.5 (4-22) and 12 (5-21) vertebrae, and SB, 3.5 (0-20) and 1 (0-20) dermatomes, values of the two groups were not related to injection speed. CONCLUSIONS AND CLINICAL RELEVANCE: The EP profile during injection was measured by separating the injection and pressure monitoring lines. The increase in epidural injection speed increased the EP, but not the ED or the SB in dogs.

Evaluation of risk factors for development of corneal ulcer after nonocular surgery in dogs: 14 cases (2009-2011).

OBJECTIVE: To evaluate the prevalence of and risk factors for development of corneal ulcers after nonocular surgery performed with general anesthesia in dogs. DESIGN: Retrospective case-control study. ANIMALS: 14 dogs with development of corneal ulcers after nonocular surgery and 718 control dogs. PROCEDURES: Medical records of dogs evaluated at the Veterinary Medical Teaching Hospital of Seoul National University from January 2009 to June 2011 were reviewed for assessment of risk factors for development of corneal ulcers. RESULTS: Among the 732 reviewed cases, 14 (1.9%) dogs of 6 breeds developed a corneal ulcer after nonocular surgery. Duration of anesthesia was significantly longer in dogs with ulcers than dogs without ulcers. The number of medications received and procedures performed were also significantly higher in dogs with ulcers than dogs without ulcers. Dogs with a small skull (OR, 8.59; 95% confidence interval [CI], 1.04 to 70.90) and dogs that received neurosurgery (OR, 21.12; 95% CI, 5.77 to 77.25) were more susceptible to development of corneal ulcers. Also, postoperative application of a fentanyl patch was a risk factor for development of corneal ulcers (OR, 4.53; 95% CI, 1.05 to 19.60). CONCLUSIONS AND CLINICAL RELEVANCE: Several risk factors were identified for development of corneal ulcers after nonocular surgery was performed with general anesthesia in dogs. Perioperative eye protection strategies and postoperative ophthalmic examination are needed to reduce the occurrence of corneal ulcers and their progression, especially for high-risk dogs and procedures.

Cranial epidural spread of contrast medium and new methylene blue dye in sternally recumbent anaesthetized dogs.

OBJECTIVE: To examine the spread of solution in the epidural space of sternally recumbent dogs. STUDY DESIGN: Prospective experimental trial. Animals Ten healthy adult Beagle dogs weighing 7.6 ± 1.1 kg. METHODS: Dogs were anaesthetized with total intravenous propofol infusion, and placed in sternal recumbency. A volume of 0.2 mL kg(-1) contrast medium (CM) containing 1% new methylene blue (MB) dye was administered into the lumbosacral epidural space. Left to right lateral radiographs using a horizontal beam were taken every 5 minutes for 45 minutes. The perpendicular height (PH) between floor of the epidural canal of the highest vertebra and that of lumbosacral spinal canal was measured on radiographs. The angle of slope from the injection point toward the highest vertebral floor was measured. Immediately after taking the last radiographic image, dogs were euthanized and a laminectomy was performed from the cervical to lumbar vertebrae for visual evaluation of MB spread. The spread of CM and of MB as counted in number of stained vertebra were compared, and each of these data sets were further compared to PH and angle, using linear regression analyses. RESULTS: The PH and angle were (mean ± SD) 3.8 ± 0.8 cm and 14.8 ± 2.8° respectively. The most cranial spread of CM was at 12.7 ± 5.7 (range: C6-L3) vertebrae, and at 14.0 ± 5.4 (range: C6-L2) vertebrae for MB staining. There were no significant correlations between PH and spread of CM (R(2) = 0.08) or MB (R(2) = 0.13), between angle and spread of CM (R(2) = 0.05) or MB (R(2) = 0.02), respectively. CM and MB demonstrated proportional relationship (R(2) = 0.82, p < 0.001). CONCLUSIONS: No significant inhibitory effect of upward slope on cranial epidural spread of the solution was observed. Other factors may have greater effect on epidural spread in sternally recumbent dogs.