• 대한수의학회지
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• 제55권4호
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• pp.221-225
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• 2015

This study evaluated the effects of alfaxalone (3 mg/kg, intravenously) on echocardiographic examination in healthy dogs using echocardiography. Six adult Beagle dogs were used for this study. Left ventricular dimensions with systolic indexes, trans-blood flow at all cardiac valvular annulus and trans-mitral tissue Doppler values were measured from routine transthoracic echocardiography. Although the changes were not statistically significant, heart rate, left ventricular end-systolic diameter, left ventricular end-diastolic diameter, peak velocities of tricuspid A-wave and transpulmonic flow were increased after alfaxalone induction, while systolic blood pressure, fractional shortening, left ventricular ejection fraction, peak velocities of mitral E-wave, mitral A wave, tricuspid E-wave, transaortic flow and medial e'-, a'- and s'-peaks decreased after alfaxalone induction. No dogs showed hypoxemia during sedation, regardless of intubation and oxygen supply. Although alfaxalone showed mild cardiovascular depression, this protocol could be a good alternative sedative protocol for echocardiographic examination in healthy dogs because the cardiovascular depression was statistically and clinically insignificant. However, further studies in dogs with heart diseases should be conducted to confirm these findings after alfaxalone induction.

• 한국동물위생학회지
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• 제39권2호
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• pp.93-99
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• 2016

The anesthetic depth and cardiovascular effect of alfaxalone constant rate infusion in dogs premedicated with xylazine or acepromazine were evaluated. Ten dogs were randomly allocated into 2 groups. In group AA, dogs were premedicated with 0.02 mg/kg of intravenous acepromazine at 15 min before induction. In group XA 1.1 mg/kg of intravenous xylazine was premedicated at 5 min before induction. The anesthesia was maintained with 6 mg/kg/hr of alfaxalone after induction with 2 mg/kg alfaxalone in both groups. In both of groups, the qualities of induction were satisfactory without any adverse event, but adequate analgesia could not be provided, according to the withdrawal test. $PaO_2$ and $SaO_2$ implied a slight hypoxemia state in XA group, while those values of group AA were not significantly changed. The acepromazine and alfaxalone combination induce mild tachycardia. The bispectral index score were significantly decreased in group XA, compared with that in group AA. The premedication of xylazine before alfaxalone constant rate infusion in this study could provide adequate analgesia during 30 min, while the premedication with acepromazine could not.

• 한국임상수의학회지
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• 제30권6호
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• pp.428-434
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• 2013

본 실험에서는 xylazine 혹은 acepromazine으로 전마취된 비글 견에서 alfaxalone과 remifentanil의 병용 지속주입 마취법을 비교 평가 하였다. 10마리의 비글견을 각 5마리씩 두 군으로 나누었다. AAR군에서는 마취 유도 15분전에 acepromazine 0.02 mg/kg을 정맥 내 투여하였고 XAR 군에서는 마취 유도 5분 전에 xylazine 1.1 mg/kg을 정맥 내 투여하였다. Alfaxalone 2 mg/kg을 정맥 투여하여 마취를 유도하였으며, 6 mg/kg/hr의 alfaxalone과 0.05 ${\mu}g/kg/min$ remifentanil을 각각 정맥 내 지속주입하여 마취를 유지하였다. Bispectral index (BIS)는 마취 후 모든 시점에서 마취전과 비교해 감소하였으며 마취 중 급격한 증가는 관찰되지 않았다. 마취기 동안의 BIS와 근전도 값은 XAR군이 AAR군에 비해 확연히 감소되었다. Xylazine 혹은 acepromazine으로 전처치한 개에서 alfaxalone 과 remifentanil의 병용 지속주입 마취법은 적절한 진통작용을 나타내었다. XAR군에서는 호흡계 기능 저하가 있었고 AAR군에서는 빈맥이 유발되어 마취법 사용에 주의가 필요하나 임상에서 적용이 가능하다고 판단된다.

• 한국임상수의학회지
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• 제34권2호
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• pp.135-139
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• 2017

This study was performed to evaluate the clinical efficacy of alfaxalone for induction of inhalation anesthesia in small animal practice. Patient data were collected according to anesthetic records (136 dogs and 14 cats) presented to the Veterinary Medical Teaching Hospital of Seoul National University for surgeries and diagnostic imaging from July 2013 to March 2014. Anesthetic results included signalment, American Society of Anesthesiologists (ASA) grade, premedicated drugs, procedures, induction quality, and recovery after anesthesia. One hundred fifty anesthetic events were classified according to the ASA grade. Three patients were ASA grade I, 52 patients grade II, 86 patients grade III, and 9 patients grade IV, respectively. The most common premedication was midazolam and hydromorphone combination (n = 59, 39.3%) follow by acepromazine and hydromorphone combination (n = 22, 14.7%). The majority of anesthesia procedures were diagnostic imaging (n = 33, 22.0%) and ophthalmic surgeries (n = 31, 20.7%), followed by soft tissue surgeries (n = 27, 18.0%), and orthopedic surgeries (n = 20, 13.3%). Intravenous alfaxalone provided smooth induction for inhalation anesthesia in almost cases, but transient apnea and twitching/paddling were observed after induction and during recovery, respectively. In addition, alfaxalone did not show pain response during intravenous administration. Alfaxalone showed smooth induction of inhalation anesthesia in dogs and cats with mild to severe systemic disease (ASA 2-4). Alfaxalone was considered as an acceptable induction agent for patients with higher risk in small animal practice.

• 대한수의학회지
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• 제56권3호
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• pp.133-137
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• 2016

Changes in the cardiovascular and bispectral index score were evaluated in dogs subjected to constant rate infusion (CRI) with alfaxalone. Fifteen dogs were assigned to three groups of 5. Groups and doses of alfaxalone were as follows: group 1, 3 mg/kg for induction and 6 mg/kg/h for CRI; group 2, 3 mg/kg for induction and 8 mg/kg/h for CRI; and group 3, 3 mg/kg for induction and 10 mg/kg/h for CRI. CRI was maintained for 1 h. Respiratory rates and blood pressures showed minimal changes; however, mild tachycardia and mild hypoxemia occurred, especially in group 3. There were some disparities between bispectral index score, electromyography and pedal withdrawal reflex test when measuring anesthetic depth. Additional premedications and/or analgesic agents would be helpful to avoid adverse effects of alfaxalone and provide improved cardiopulmonary functions.

• Journal of Veterinary Science
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• 제23권6호
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• pp.68.1-68.8
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• 2022

Background: Studies on anesthetized dogs regarding pulse pressure variation (PPV) are increasing. The influence of respiratory rate (RR) on PPV, in mechanically ventilated dogs, has not been clearly identified. Objectives: This study evaluated the influence of RR on PPV in mechanically ventilated healthy dogs after hemorrhage. Methods: Five healthy adult Beagle dogs were premedicated with intravenous (IV) acepromazine (0.01 mg/kg). Anesthesia was induced with alfaxalone (3 mg/kg IV) and maintained with isoflurane in 100% oxygen. The right dorsal pedal artery was cannulated with a 22-gauge catheter for blood removal, and the left dorsal pedal artery was cannulated and connected to a transducer system for arterial blood pressure monitoring. The PPV was automatically calculated using a multi-parameter monitor and recorded. Hemorrhage was induced by withdrawing 30% of blood (24 mL/kg) over 30 min. Mechanical ventilation was provided with a tidal volume of 10 mL/kg and a 1:2 inspiration-to-expiration ratio at an initial RR of 15 breaths/min (baseline). Thereafter, RR was changed to 20, 30, and 40 breaths/min according to the casting lots, and the PPV was recorded at each RR. After data collection, the blood was transfused at a rate of 10 mL/kg/h, and the PPV was recorded at the baseline ventilator setting. Results: The data of PPV were analyzed using the Friedman test followed by the Wilcoxon signed-rank test (p < 0.05). Hemorrhage significantly increased PPV from 11% to 25% at 15 breaths/min. An increase in RR significantly decreased PPV from 25 (baseline) to 17%, 10%, and 10% at 20, 30, and 40 breaths/min, respectively (all p < 0.05). Conclusions: The PPV is a dynamic parameter that can predict a dog's hemorrhagic condition, but PPV can be decreased in dogs under high RR. Therefore, careful interpretation may be required when using the PPV parameter particularly in the dogs with hyperventilation.

• 한국임상수의학회지
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• 제33권4호
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• pp.234-236
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• 2016

A 14 kg, 9-year-old, spayed female, Cocker Spaniel was presented to the Veterinary Medical Teaching Hospital of Seoul National University with a history of head tilt and circling. Otitis externa and media were diagnosed by computerized tomography, and total ear canal ablation was performed. In preanesthetic evaluation, systemic hypertension and second-degree atrioventricular block were observed, but there was no regurgitation through the heart valves. Systemic hypertension was managed with amlodipine (0.1 mg/kg, PO, BID) for the anesthesia. The dog was premedicated with cefazolin (22 mg/kg, IV) and midazolam (0.2 mg/kg, IV). Anesthesia was induced with alfaxalone (2 mg/kg, IV) and maintained with isoflurane and 100% oxygen following intubation. During surgery, vital signs (heart rate, respiratory rate, blood pressure, end tidal carbon dioxide partial pressure and body temperature) were maintained within normal ranges, but bradycardia was observed and corrected with glycopyrrolate (5 ug/kg IV, twice). During subcuticular suture, electrohemostasis was applied at the incision line, which was close to the trigeminal nerve. In no time at all, heart rate dramatically decreased from 110 to 60 beats per minute. No additional treatment was done because mean blood pressure was maintained above 70 mmHg. The heart rate recovered according to the decrease of end tidal isoflurane concentration and there were no complications associated with the anesthesia and surgery. Sudden bradycardia after electrical stimulation around the trigeminal nerve was considered as trigeminocardiac reflex (TCR). It is recommended to be careful of bradycardia from TCR when electrocautery is used in the craniofacial area during surgery.