Evaluation of noninvasive monitoring techniques in domestic ferrets (Mustela putorius furo).

OBJECTIVE: To evaluate instrument placement and accuracy of indirect physiologic monitoring techniques in anesthetized domestic ferrets. ANIMALS: 10 healthy adult female ferrets (Mustela putorius furo). PROCEDURE: Direct arterial blood pressure measurement and arterial blood sample collection were performed in ferrets. A pulse oximeter probe was clipped to a forefoot or hind foot; an airway adaptor for capnography was attached to the endotracheal tube; and a sphygmomanometer cuff and Doppler flow probe were positioned on the tail. Isoflurane and nitrous oxide concentrations were varied to induce episodes of hypotension or hypoxia, respectively. Aforementioned noninvasive techniques were compared with direct methods of arterial blood gas analysis, hemoximetry, and arterial blood pressure measurement. Simultaneously obtained direct and indirect measurements were statistically evaluated for mean and SD of the differences, and SEM, and subjectively, for ease of use and relevance to the clinical situation. RESULTS: Values obtained from pulse oximetry were closely related to oxygen saturation measured by blood gas analysis (O2sat). The mean (+/- SD) difference for all results was -0.49 (+/- -4.09)%. The most precise measurements were obtained when O2sat was between 90 and 100%. Capnography measurements varied between ranges. The most accurate measurements were obtained when PaCO2 was < 25 mm of Hg, when the mean difference was 1.6 (+/- -3.01) mm of Hg. Indirect blood pressure measurement consistently underestimated the direct blood pressure value. CONCLUSIONS AND CLINICAL RELEVANCE: Pulse oximetry is a convenient and accurate method for monitoring oxygen saturation in domestic ferrets. Capnography is useful for monitoring respiratory rate and pattern, but may present difficulties in interpretation of actual PaCO2. Indirect blood pressure monitoring is not accurate by use of current methods in ferrets.

Development and comparison of transperitoneal and retroperitoneal approaches to laparoscopic-assisted aortofemoral bypass in a porcine model.

PURPOSE: Transperitoneal and retroperitoneal approaches to video-assisted aortofemoral bypass were developed and compared using gasless laparoscopic techniques in a porcine model. METHODS: Ten pigs were randomized to either a transperitoneal or retroperitoneal approach. Aortic clamp time, total operative time, and complications were recorded. Both operations used an external lift device to maintain the working space. Retroperitoneal operations first used serial balloon inflation to dissect the retroperitoneum. After exposure of the infrarenal aorta, a graft was tunneled under endoscopic visualization. End-to-side aortic and femoral anastomoses were created with conventional instruments through 4 cm incisions. RESULTS: Mean +/- SEM aortic clamp time, operative duration, and graft patency rates were similar for both approaches (difference not significant by unpaired t test). Intraoperative complications related to the use of the laparoscopic technique included injury to the bladder and small bowel (n=2) and occurred only in the transperitoneal group. CONCLUSIONS: The use of a gasless technique allowed direct visualization, standard instrumentation, and conventional anastomotic techniques. The retroperitoneal approach used the peritoneal sac to exclude the bowel, simplifying the aortic dissection. Gasless laparoscopic-assisted aortofemoral bypass can be performed by both transperitoneal and retroperitoneal approaches and holds promise as a minimally invasive treatment for aortoiliac occlusive disease.

Evaluation of detomidine anesthetic combinations in the rabbit.

Detomidine, a potent alpha 2-adrenergic receptor agonist, was chosen for study alone and in combination with ketamine with or without diazepam. Four regimens were evaluated: detomidine (150 micrograms/kg of body weight) alone (D); ketamine (35 mg/kg) and detomidine (150 micrograms/kg) (KD); ketamine (35 mg/kg) and high-dose detomidine (300 micrograms/kg) (KDh); and ketamine (35 mg/kg), diazepam (1 mg/kg), and detomidine (150 micrograms/kg) (KDD). The same six rabbits were anesthetized with each combination at weekly intervals. Atropine (0.04 mg/kg) was administered as a preanesthetic 5 min prior to test substance administration. All agents were administered IM, except for diazepam, which was administered IV. Heart and respiratory rates, mean arterial blood pressure, and arterial blood gas tensions were measured. Pedal, palpebral, and righting reflexes also were evaluated. Cardiopulmonary depression, as indicated by decrease in heart and respiratory rates, blood pH, PO2, and increase in PCO2, was observed in all groups. With the exception of heart rate, detomidine used alone caused the least depression of these parameters. Reflexes were consistently lost only after KDh and KDD administrations. The pedal reflex, used as an index of anesthetic depth, was lost in response to KDh and KDD for 56.7 +/- 11.6 and 43.8 +/- 7.4 min, respectively (mean +/- SEM). Three of the six rabbits were anorectic after KDh administration. Necropsy and histologic evaluation revealed myocardial necrosis and fibrosis in five animals. Due to the inconsistent reflex loss in response to KD and D and inappetance associated with KDh, these combinations were not considered safe or reliable.(ABSTRACT TRUNCATED AT 250 WORDS)