Development and evaluation of an anatomically designed and 3D printed device to enhance orotracheal intubation success in rabbits by inexperienced veterinarians.

OBJECTIVE: To assess whether the use of a three-dimensional (3D) printed device enhances the success rate of orotracheal intubation in rabbits. STUDY DESIGN: Prospective, crossover randomized controlled trial. ANIMALS: A total of six mixed-breed rabbits. METHODS: A device to guide the endotracheal tube was designed based on computed tomography images and then manufactured using 3D printing. Rabbits were randomly assigned for intubation by two inexperienced veterinarians using the blind (BLI), borescope- (BOR) or device- (DEV) guided techniques. Success rate, number of attempts, time to success, injury scores and propofol dose were recorded and compared. Significance was considered when p < 0.05. RESULTS: Success rate was higher in DEV (58.3%) than in BLI (8.3%) (p < 0.023), but not different from that in BOR (41.6%). Total time until successful intubation was lower in DEV (45 ± 23 seconds) and BOR (85 ± 62 seconds) than in BLI (290 seconds; p < 0.006). Time for the successful attempt was lower for DEV (35 ± 10 seconds) and BOR (74 ± 43 seconds) than in BLI (290 seconds; p < 0.0001). The propofol dose required was lower for DEV (2.3 ± 1.2 mg kg-1) than for BLI (3.4 ± 1.6 mg kg-1) (p < 0.031), but not different from BOR (2.4 ± 0.9 mg kg-1). Number of attempts and oxygen desaturation events were not different among techniques (p < 0.051 and p < 0.326, respectively). Injury scores [median (range)] before and after attempts were different in BLI [0 versus 1 (0-3), p < 0.005] and BOR [0 (0-1) versus 1 (0-3), p < 0.002] but not in DEV [0 (0-2) versus 0 (0-3), p < 0.109]. CONCLUSIONS AND CLINICAL RELEVANCE: The device facilitated orotracheal intubation with a time similar to the borescope-guided technique but faster than the traditional blind technique.

Evaluation of analgesic, sympathetic and motor effects of 1% and 2% lidocaine administered epidurally in dogs undergoing ovariohysterectomy.

OBJECTIVE: To compare, versus a control, the sensory, sympathetic and motor blockade of lidocaine 1% and 2% administered epidurally in bitches undergoing ovariohysterectomy. STUDY DESIGN: Randomized, blinded, controlled clinical trial. ANIMALS: A total of 24 mixed-breed intact female dogs. METHODS: All dogs were administered dexmedetomidine, tramadol and meloxicam prior to general anesthesia with midazolam-propofol and isoflurane. Animals were randomly assigned for an epidural injection of lidocaine 1% (0.4 mL kg-1; group L1), lidocaine 2% (0.4 mL kg-1; group L2) or no injection (group CONTROL). Heart rate (HR), respiratory rate (fR), end-tidal partial pressure of carbon dioxide (Pe'CO2), and invasive systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures were recorded every 5 minutes. Increases in physiological variables were treated with fentanyl (3 µg kg-1) intravenously (IV). Phenylephrine (1 µg kg-1) was administered IV when MAP was <60 mmHg. Postoperative pain [Glasgow Composite Pain Score - Short Form (GCPS-SF)] and return of normal ambulation were recorded at 1, 2, 3, 4 and 6 hours after extubation. RESULTS: There were no differences over time or among groups for HR, fR, Pe'CO2 and SAP. MAP and DAP were lower in epidural groups than in CONTROL (p = 0.0146 and 0.0047, respectively). There was no difference in the use of phenylephrine boluses. More fentanyl was administered in CONTROL than in L1 and L2 (p = 0.011). GCPS-SF was lower for L2 than for CONTROL, and lower in L1 than in both other groups (p = 0.001). Time to ambulation was 2 (1-2) hours in L1 and 3 (2-4) hours in L2 (p = 0.004). CONCLUSIONS AND CLINICAL RELEVANCE: Epidural administration of lidocaine (0.4 mL kg-1) reduced fentanyl requirements and lowered MAP and DAP. Time to ambulation decreased and postoperative pain scores were improved by use of 1% lidocaine compared with 2% lidocaine.

Sedative and physiologic effects of tiletamine-zolazepam following buccal administration in cats.

OBJECTIVES: The aim of this study was to describe the sedative and some physiological effects of tiletamine-zolazepam following buccal administration (BA) in cats. METHODS: Seven healthy spayed European shorthair cats (three males, four females) were studied twice in this randomized, blinded, crossover study. Each cat received two doses of tiletamine-zolazepam by BA: the low-dose (LD) group consisted of 5 mg/kg of each drug, and the high-dose (HD) group consisted of 7.5 mg/kg of each. Baseline systolic blood pressure (SAP), heart rate (HR), respiratory rate (RR) and a sedation score were recorded prior to administration of each treatment. The same variables plus the percentage of hemoglobin saturated with oxygen as measured by pulse oximetry (SpO2) were recorded at predefined intervals for the next 2 h. RESULTS: All cats completed the study. No retching or vomiting were observed. Hypersalivation was observed in 0/7 and 3/7 for LD and HD groups, respectively (P = 0.2). There were significant changes in scores over time for posture, response to clippers and response to manual restraint for both groups, without differences between groups. RR, HR and SAP changed significantly over time. SAP and RR were significantly lower for the HD than for the LD group. No values for hemoglobin saturation <95% were observed. CONCLUSIONS AND RELEVANCE: BA of tiletamine-zolazepam at the doses studied here is a simple and effective method for chemical restraint in cats, where the LD group had a lower impact on SAP and RR than the HD group.

Comparison of two sedation protocols for short electroretinography in cats.

Objectives The objectives were to compare two different sedative combinations, xylazine-ketamine and dexmedetomidine-ketamine, for the short electroretinography (ERG) protocol and their impact on sedative effect, reversal times and physiological variables in cats. Methods Six healthy spayed female domestic cats were sedated using one of two ketamine-containing protocols: intramuscular xylazine hydrochloride (1 mg/kg) plus ketamine hydrochloride (3 mg/kg) (XK), and dexmedetomidine hydrochloride (5 µg/kg) plus ketamine hydrochloride (3 mg/kg) (DK). A short ERG protocol was recorded from the left eye of each cat under XK and DK sedation. Thirty minutes later, the effects were reversed with yohimbine or atipamezole for the XK and DK treatment, respectively. The cats were evaluated for time to recumbency, time to head elevation, and time to standing position after reversal treatments. Other variables recorded were: systolic blood pressure, cardiac rhythm, heart rate, pulse oximetry and respiratory rate. Recorded ERG variables included a- and b-wave amplitudes and implicit times under photopic, scotopic and scotopic mixed ERG conditions. Results Time to lateral recumbency with XK was shorter than for DK ( P <0.05). After reversal, head elevation and standing position times were significantly longer for the XK than the DK group ( P <0.05). Heart rate increased and systolic blood pressure decreased from baseline in both groups ( P <0.05), but there were no significant differences between treatment groups. The b-wave amplitude recorded in the photopic study of cats treated with XK was lower than in animals treated with DK ( P <0.05). No other significant differences in ERG variables were observed between treatment groups ( P >0.05). Conclusions and relevance The present study shows that XK and DK treatments are chemical restraint alternatives for ERG recording in cats, with significant differences only in the photopic b-wave amplitude.