Wei-Ming Lee

EFFECTS OF INTRAVENOUS DEXMEDETOMIDINE ON CARDIAC CHARACTERISTICS MEASURED USING RADIOGRAPHY AND ECHOCARDIOGRAPHY IN SIX HEALTHY DOGS

Dexmedetomidine is a highly specific and selective α2-adrenergic receptor agonist widely used in dogs for sedation or analgesia. We hypothesized that dexmedetomidine may cause significant changes in radiographic and echocardiographic measurements. The objective of this prospective cross-sectional study was to test this hypothesis in a sample of six healthy dogs. Staff-owned dogs were recruited and received a single dose of dexmedetomidine 250 μg/m(2) intravenously. Thoracic radiography and echocardiography were performed 1 h before treatment, and repeated 10 and 30 min after treatment, respectively. One observer recorded cardiac measurements from radiographs and another observer recorded echocardiographic measurements. Vertebral heart score and cardiac size to thorax ratio on the ventrodorsal projection increased from 9.8 ± 0.6 v to 10.3 ± 0.7 v (P = 0.0007) and 0.61 ± 0.04 to 0.68 ± 0.03 (P = 0.0109), respectively. E point-to-septal separation and left ventricle internal diameter in diastole and systole increased from 2.4 ± 1.1 to 6.6 ± 1.9 mm, 32.3 ± 8.1 to 35.5 ± 8.8 mm, and 19.4 ± 6 to 27.0 ± 7.2 mm, respectively (P < 0.05). Fractional shortening and sphericity index decreased from 40.7 ± 5.8 to 24.4 ± 2.9%, and 1.81 ± 0.07 to 1.58 ± 0.04, respectively (P < 0.05). Moderate-to-severe mitral regurgitation and mild pulmonic regurgitation occurred in all dogs after dexmedetomidine administration. Findings indicated that dexmedetomidine could cause false-positive diagnoses of valvular regurgitation and cardiomegaly in dogs undergoing thoracic radiography and echocardiography.

PLETH VARIABILITY INDEX-GUIDED FLUID THERAPY LOWERS POST-OPERATIVE LACTATE LEVELS IN DOGS UNDERGOING ELECTIVE ABDOMINAL SURGERY: A RANDOMIZED CONTROLLED TRIAL

To evaluate the hemodynamic optimization effect of pleth variability index (PVI)-guided fluid therapy during abdominal surgery on tissue perfusion, 19 client-owned dogs that underwent elective abdominal surgery were randomized into control (n=10) and PVI (n=9) groups. In the control group, perioperative fluid management was based on the 2013 AAHA/AAFP Fluid Therapy Guidelines for Dogs and Cats. In the PVI group, the fluid rate was maintained based on basic daily requirements. If PVI was higher than 15% for >5min, 3–5mL/kg of crystalloid fluid bolus was infused. The tissue perfusion indicator, lactate levels, was measured at the time of intubation, extubation, and 6, 12 and 24h postoperatively. There were no significant differences in total and average fluid infused between control and PVI groups. The control group had significantly higher lactate levels than that of the PVI group at 12h postoperatively (2.2±1.0mmol/L versus 1.1±0.6mmol/L, p=0.008) and overall postoperatively (1.8±0.8mmol/L versus 1.2±0.5m...

COMPARISON OF ONSITE INFILTRATION AND CONSTANT RATE INFUSION FOR POSTOPERATIVE ANALGESIA IN DOGS WITH MAMMARY TUMORS UNDERGOING BILATERAL RADICAL MASTECTOMY AND OVARIOHYSTERECTOMY

Analgesia of the wide surgical excision region in surgeries such as bilateral radical mastectomy plays an important role in postoperative care. Opioids are effective in alleviating pain; however, they are sometimes difficult to obtain in most local veterinary hospitals. The objective of this research was to compare the efficacies of (1) onsite infiltration analgesia with lidocaine and bupivacaine (group I, n=6) and intravenous injection with buprenorphine and (2) constant rate infusions (CRIs) of fentanyl and ketamine (group II, n=6) for postoperative analgesia after bilateral radical mastectomy and ovariohysterectomy in dogs with mammary tumors. The results showed that a combination of infiltration with lidocaine and bupivacaine and intravenous injection with buprenorphine was as effective as CRIs of fentanyl and ketamine. Infiltration analgesia with lidocaine and bupivacaine may be an option for analgesia in dogs undergoing bilateral mastectomy and ovariohysterectomy and may help reducing pure μ-opioid ...

Emphysematous pyometra secondary to Enterococcus avium infection in a dog

A 5-year-old female intact Mastiff dog was presented with a history of vaginal discharge for 1 day. Physical examination revealed a sanguineo-purulent vaginal discharge and systemic inflammatory response syndrome. Abdominal radiographs showed several dilated and gas- filled tubular loops. The differential diagnoses included emphysematous pyometra or small intestinal mechanical ileus. Surgical exploration of the abdomen demonstrated a severely dilated and gas-filled uterus, and emphysematous pyometra was confirmed. The patients clinical signs resolved after ovariohysterectomy. Histopathology revealed mild endometrial cystic hyperplasia with infiltration of inflammatory cells in the superficial endometrial epithelia. Enterococcus avium, an α-hemolytic gram-positive coccus, was isolated from the uterus. This paper highlights the radiographic features of emphysematous pyometra and a pathogen that has never been reported to be associated with canine pyometra previously.

EFFECT OF TRIVALENT CHROMIUM ON GROWTH HORMONE AND INSULIN-LIKE GROWTH FACTOR-I IN OVARIOHYSTERECTOMIZED RATS

Changes in sex hormones following neutering appear to influence development of obesity by directly affecting satiety and metabolism, and indirectly affecting cell metabolism and hormone regulation. Trivalent chromium (Cr3+), an essential trace element in humans and animals, plays an important role in the metabolism and regulation of hormones such as growth hormone (GH) and insulin-like growth factor 1 (IGF-1). This study is to observe whether the effect of Cr3+ on body weight gain and regulation of GH and IGF-1 after estradiol deprivation in rat model. All 8-week-old Sprague Dawley (SD) female rats were divided into four groups (n=6): control, ovariohysterectomy (OHE), chromium (Cr) and OHE with Cr groups. GH and IGF-1 were determined at 14-, 18- and 22-week-old, respectively. In results, the body weights of ovariohysterectomized rats had been significantly higher (p<0.05) than that of intact rats since 12-week-old. The GH levels in OHE with Cr3+ supplement group were decreased gradually and even reached to significantly lower in comparison to control group at 22 week-old. The IGF-1 levels in both OHE groups were significantly higher (p<0.05) than that in control group at 14- and 18-week-old, respectively. The results of this study did not provide the evidence concerning that the daily Cr3+ supplement can regulate the GH and IGF-1 levels due to estradiol deprivation in ovariohysterectomized rats.