Luca Bellini

Abdominal ultrasound features and reference values in 21 healthy rabbits

This study aimed to determine the ultrasonographic features and reference values of the abdominal anatomy in mixed-breed dwarf rabbits. Complete abdominal ultrasonographic examination was performed in 21 mixed-breed rabbits (12 males and 9 females) referred for examination to the Department of Animal Medicine, Production and Health, University of Padua, Italy. All animals were sedated during the procedure. The ultrasonographic anatomy of the abdomen was determined, including measurement (mean±SD) of the right kidney (length 2.87±0.34 mm; width 1.62±0.17 mm; height 1.66±0.14 mm) and left kidney (length 2.86±0.33 mm; width 1.72±0.19; height 1.58±0.15 mm), left adrenal gland (width 0.38±0.11 mm; length 0.71±0.14), right adrenal gland (width 0.34±0.08 mm; length 0.73±0.15 mm) and thickness of the walls of the stomach (0.10±0.01 mm), pylorus (0.28±0.04 mm), duodenum (0.19±0.04 mm), sacculus rotundus (0.22±0.06 mm), caecum (0.08±0.01 mm), appendix (0.19±0.04 mm), spiral loop of the ascending colon (0.14±0.04 mm) and distal colon (0.10±0.02 mm). A significant positive correlation between bodyweight and kidney size, adrenal gland length, stomach wall and sacculus rotundus wall was detected.

Abdominal anatomic features and reference values determined by use of ultrasonography in healthy common rats (Rattus norvegicus)

OBJECTIVE To determine ultrasonographic features and reference values of the anatomy of the abdomen of common rats (Rattus norvegicus). ANIMALS 20 adult male and 20 adult female rats. PROCEDURES A complete abdominal ultrasonographic examination was performed with the rats sedated. The cadavers of 4 rats were used for anatomic comparisons. Two cadavers were dissected and 2 cadavers were frozen and then cross-sectioned by use of an electric bandsaw. Slices were cleaned with water and photographed on each side. Correlations between variables were determined. RESULTS The ultrasonographic anatomy of the abdomen was determined, including measurements of the kidneys and adrenal glands and thickness of the walls of the stomach (saccus caecus, fundus, and pylorus), duodenum, and cecum. A significant positive correlation between kidney size and body weight was detected. The dorsoventral measurements of the left and right adrenal gland were significantly different, regardless of sex. Dorsoventral measurements of the right adrenal gland were significantly different between males and females. CONCLUSIONS AND CLINICAL RELEVANCE The ultrasonographic images and data provided an atlas of the ultrasonographic anatomy of common rats that may be useful to veterinary radiologists, clinicians, and researchers.

Evaluation of sedation and clinical effects of midazolam with ketamine or dexmedetomidine in pet rabbits

The effects of two sedation protocols combining midazolam with ketamine (ketamine group) or dexmedetomidine (dexmedetomidine group) were studied in dwarf companion rabbits undergoing abdominal ultrasound scan. The onset of sedation was faster in the ketamine group; a few rabbits in the dexmedetomidine group required additional doses to lose the righting reflex, although sedation time was not different between groups. A semi-quantitative scale was used to score sedation quality, which was higher in rabbits that received dexmedetomidine rather than ketamine. Pulse rate was lower in the dexmedetomidine group (206 vs 240 bpm), although Doppler blood pressure was higher than in the ketamine group (109 vs 89 mm Hg). Respiratory rate decreased in relation to the baseline values with both protocols but arterial haemoglobin saturation with oxygen was maintained similar to the pre-sedation values throughout the entire procedure, regardless of protocol used and without oxygen supplementation. Both protocols allowed performance of ultrasound scanning, although dexmedetomidine may be preferred if a deep sedation level is required.

Evaluation of three medetomidine-based protocols for chemical restraint and sedation for non-painful procedures in companion rats (Rattus norvegicus)

Three medetomidine-based protocols were evaluated for sedation in companion rats undergoing diagnostic procedures. Group Me received medetomidine at 150 μg/kg intramuscularly (IM); group Me-Bu received medetomidine 100 μg/kg IM and butorphanol 2 mg/kg IM, and group Me-Bu-Mi received medetomidine 50 μg/kg IM, butorphanol 2 mg/kg IM and midazolam 1 mg/kg IM. The righting reflex disappeared more quickly in the Me-Bu-Mi group, but recovery after atipamezole was longer. In group Me, a palpebral reflex was present throughout sedation in more rats than in the other two groups. Pulse and respiratory rates were higher when lower doses of medetomidine were used, although arterial haemoglobin O2 saturation was similar among groups. All protocols tested produced adequate sedation lasting 25 min.

Intraoperative end-tidal concentration of isoflurane in cats undergoing ovariectomy that received tramadol, buprenorphine or a combination of both.

Objectives The aim of the study was to evaluate the end-tidal concentration of isoflurane required to maintain heart and respiratory rate within ± 20% of basal measurement in cats undergoing ovariectomy that received buprenorphine, tramadol or a combination of both. Methods Thirty cats, divided into three groups, were enrolled in a simple operator-blinded, randomised study. Cats received acepromazine (0.03 mg/kg) and one of the following treatments: buprenorphine (0.02 mg/kg), tramadol (2 mg/kg) or a combination of both. Anaesthesia was induced with propofol and maintained with isoflurane titrated in order to maintain heart and respiratory rate within the target values recorded before premedication. Results Groups were similar for age, weight, dose of propofol administered, sedation and recovery scores. Cats receiving tramadol with buprenorphine were extubated earlier after isoflurane discontinuation. No statistical differences were detected in end-tidal fraction of isoflurane between buprenorphine alone or with tramadol. In cats that received tramadol or buprenorphine alone, ovarian pedicle traction caused a statistical increase in end-tidal isoflurane concentration compared with that measured during incision and suture of the skin. In cats that received the combination of tramadol plus buprenorphine no differences among surgical time points were observed. Conclusions and relevance Tramadol added to buprenorphine did not provide any advantage in decreasing the end-tidal fraction of isoflurane compared with buprenorphine alone, although it is speculated there may be an infra-additive interaction between tramadol and buprenorphine in cats.

Neuromuscular blockade of atracurium in permissive hypercapnic versus normocapnic swine undergoing laparoscopy

Neuromuscular blocking agents (NMBAs) are commonly used in experimental laparoscopy in swine undergoing carbon dioxide pneumoperitoneum. Hypercapnia may be present and may prolong NMBAs’ pharmacologic activity. The aim of this study is to evaluate the effect of permissive hypercapnia on the neuromuscular blockade of atracurium in swine. Six Large White swine weighing 30.5 ± 1.6 kg were sedated with intramuscular ketamine and medetomidine, after which anaesthesia was induced with propofol and maintained with sevoflurane. Atracurium 0.4 mg/kg was administered intravenously and the neuromuscular block monitored by acceleromyography during normocapnic and hypercapnic conditions (PaCO2 range 35–45 mmHg and 60–70 mmHg, respectively). Onset time and time to reach a train of four ratio (TOFR) of 0.7 and 0.9 were recorded. Cardiorespiratory parameters, electrolytes and acid-base status were measured under both conditions. Onset time was similar between the two conditions. Time to reach a TOFR of 0.7 and 0.9 (duration of the neuromuscular block) was longer in hypercapnic compared to normocapnic animals being 1325 ± 300 vs 855 ±111 (p = 0.002) and 1823 ± 434 vs 1218 ± 210 seconds (p = 0.005), respectively. Three hypercapnic swine had a TOF count of 2 and 1 instead of a count of 4 with fade. Permissive hypercapnia was associated with a decrease in pH from 7.444 ± 0.039 to 7.257 ± 0.025 (p < 0.001). No differences were observed for heart rate, end-tidal concentration of sevoflurane, body temperature and arterial haemoglobin saturation. Nonetheless, hypercapnic swine had a statistically significant increase in mean arterial pressure (p = 0.020) and plasma potassium concentration (p = 0.003). The values of PaCO2 achieved during hypercapnia were well tolerated in swine undergoing CO2 pneumoperitoneum for laparoscopy. Permissive hypercapnia increased the duration of the atracurium effect and caused an increase in the intensity of the neuromuscular block in few swine.