Objectives: 1) To describe electroencephalogram (EEG) appearance in the awake dog and compare these results with EEG recordings after low dose medetomidine (2 μg/kg IV) followed by atipamezole (10 μg/kg, IM);2) To i...Objectives: 1) To describe electroencephalogram (EEG) appearance in the awake dog and compare these results with EEG recordings after low dose medetomidine (2 μg/kg IV) followed by atipamezole (10 μg/kg, IM);2) To institute EEG recordings after low dose medetomidine or dexmedetomidine as a standard of practice if focal abnormalities and amplitudes were not significantly altered by pharmaceuticals in Phase 1 of this study. Methods: Electroencephalograms were performed on eight clinical canine patients with suspected intracranial disease involving the prosencephalon. A five lead montage was used to record the EEGs. Each dog had an awake, baseline recording followed by an EEG performed after administration of low dose medetomidine (2 μg/kg IV) then atipamezole (10 μg/kg, IM). In the second phase of this study, the same dose of medetomidine or dexmedetomidine at 1 μg/kg IV and atipamezole (10 μg/kg, IM) were used in the evaluation of 20 clinical patients with suspected neurologic disease. Results: In Phase 1, awake recordings were laced with movement artifacts. After medetomidine and atipamezole, EEG waveforms were slower. Following atipamezole, however, the frequencies were observed to increase with time. Statistical evaluation revealed significantly more artifacts in baseline recordings. No statistically significant change was observed in focal abnormalities or amplitude. In Phase 2, the a2-adrenoreceptor agonists followed by atipamezole without the use of lidocaine produced clinically reliable results. Clinical Significance: Quality and diagnostic electroencephalogram (EEG) recordings are frequently inconvenient to obtain in the awake dog. Movement results in artifacts and dislodged leads. Administration of low dose medetomidine or dexmedetomidine followed by atipamezole reliably reduced the impact of movement artifacts and produced clinically valid EEG recordings in dogs.展开更多
The purpose of this study was to evaluate cardiopulmonary effects of MLBP-TIVA with or without controlled ventilation in horses and to determine effects of positioning on cardiovascular function in mechanically ventil...The purpose of this study was to evaluate cardiopulmonary effects of MLBP-TIVA with or without controlled ventilation in horses and to determine effects of positioning on cardiovascular function in mechanically ventilated horses.Five healthy adult horses were anesthetized with MLBP-TIVA for 2-hours on 3-occasions at 4-week interval with (CMV-group) or without controlled mechanical ventilation (SB-group) and in lateral (LR-group) or dorsal (DRgroup) recumbency.Anesthesia was induced with lidocaine (1 mg/kg: IV) and propofol (3 mg/kg: IV) following premedications with medetomidine (0.005 mg/kg: IV) and butorphanol (0.02 mg/kg: IV),and then maintained by propofol infusion combined with constant rate infusions of medetomidine (0.0035 mg/kg/h),lidocaine (3 mg/kg/h)and butorphanol (0.024 mg/kg/h).Data were compared between groups using repeated-measures ANOVA.The level of significance was set at P 【 0.05.Cardiovascular parameters were maintained within acceptable ranges in SB-group.However,severe hypercapnia with insufficient oxygenation was observed (PaCO2: 83 ~103 mmHg,arterial O2pressure [PaO2]: 155 ~171 mmHg).In CMV-group,significant decreases in heart rate (29 ~ 31 beats/min,P = 0.020),cardiac output (17 ~ 21 L/min,P= 0.005) and PaCO2 (42 ~ 50 mmHg,P = 0.001) and a significant increase in PaO2 (395 ~ 419 mmHg,P =0.005) were observed compared to SB-group.Mean pulmonary arterial pressure and mean atrial blood pressure were significantly decreased in DR-group compared to LR-group (18 ~ 20 mmHg vs 27 ~ 31 mmHg,P = 0.001 and 8 ~ 9 mmHg vs 15 ~ 17 mmHg,P = 0.003,respectively).Arterial O2pressure was significantly lower in DR-group than in LR-group (171 ~301 mmHg vs 385 ~416 mmHg,P =0.043).Cardiovascular functions were maintained within acceptable range during MLBP-TIVA in horses.Controlled ventilation is useful for improving hypercapnia and oxygenation.Also,MLBP-TIVA provides a preservation of cardiovascular function leading to compensation for decreased preload in horses positioned in dorsal recumbency.展开更多
文摘Objectives: 1) To describe electroencephalogram (EEG) appearance in the awake dog and compare these results with EEG recordings after low dose medetomidine (2 μg/kg IV) followed by atipamezole (10 μg/kg, IM);2) To institute EEG recordings after low dose medetomidine or dexmedetomidine as a standard of practice if focal abnormalities and amplitudes were not significantly altered by pharmaceuticals in Phase 1 of this study. Methods: Electroencephalograms were performed on eight clinical canine patients with suspected intracranial disease involving the prosencephalon. A five lead montage was used to record the EEGs. Each dog had an awake, baseline recording followed by an EEG performed after administration of low dose medetomidine (2 μg/kg IV) then atipamezole (10 μg/kg, IM). In the second phase of this study, the same dose of medetomidine or dexmedetomidine at 1 μg/kg IV and atipamezole (10 μg/kg, IM) were used in the evaluation of 20 clinical patients with suspected neurologic disease. Results: In Phase 1, awake recordings were laced with movement artifacts. After medetomidine and atipamezole, EEG waveforms were slower. Following atipamezole, however, the frequencies were observed to increase with time. Statistical evaluation revealed significantly more artifacts in baseline recordings. No statistically significant change was observed in focal abnormalities or amplitude. In Phase 2, the a2-adrenoreceptor agonists followed by atipamezole without the use of lidocaine produced clinically reliable results. Clinical Significance: Quality and diagnostic electroencephalogram (EEG) recordings are frequently inconvenient to obtain in the awake dog. Movement results in artifacts and dislodged leads. Administration of low dose medetomidine or dexmedetomidine followed by atipamezole reliably reduced the impact of movement artifacts and produced clinically valid EEG recordings in dogs.
文摘The purpose of this study was to evaluate cardiopulmonary effects of MLBP-TIVA with or without controlled ventilation in horses and to determine effects of positioning on cardiovascular function in mechanically ventilated horses.Five healthy adult horses were anesthetized with MLBP-TIVA for 2-hours on 3-occasions at 4-week interval with (CMV-group) or without controlled mechanical ventilation (SB-group) and in lateral (LR-group) or dorsal (DRgroup) recumbency.Anesthesia was induced with lidocaine (1 mg/kg: IV) and propofol (3 mg/kg: IV) following premedications with medetomidine (0.005 mg/kg: IV) and butorphanol (0.02 mg/kg: IV),and then maintained by propofol infusion combined with constant rate infusions of medetomidine (0.0035 mg/kg/h),lidocaine (3 mg/kg/h)and butorphanol (0.024 mg/kg/h).Data were compared between groups using repeated-measures ANOVA.The level of significance was set at P 【 0.05.Cardiovascular parameters were maintained within acceptable ranges in SB-group.However,severe hypercapnia with insufficient oxygenation was observed (PaCO2: 83 ~103 mmHg,arterial O2pressure [PaO2]: 155 ~171 mmHg).In CMV-group,significant decreases in heart rate (29 ~ 31 beats/min,P = 0.020),cardiac output (17 ~ 21 L/min,P= 0.005) and PaCO2 (42 ~ 50 mmHg,P = 0.001) and a significant increase in PaO2 (395 ~ 419 mmHg,P =0.005) were observed compared to SB-group.Mean pulmonary arterial pressure and mean atrial blood pressure were significantly decreased in DR-group compared to LR-group (18 ~ 20 mmHg vs 27 ~ 31 mmHg,P = 0.001 and 8 ~ 9 mmHg vs 15 ~ 17 mmHg,P = 0.003,respectively).Arterial O2pressure was significantly lower in DR-group than in LR-group (171 ~301 mmHg vs 385 ~416 mmHg,P =0.043).Cardiovascular functions were maintained within acceptable range during MLBP-TIVA in horses.Controlled ventilation is useful for improving hypercapnia and oxygenation.Also,MLBP-TIVA provides a preservation of cardiovascular function leading to compensation for decreased preload in horses positioned in dorsal recumbency.
