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Biomedical subjects

William W Muir

Publications and source records attributed to William W Muir.

At least 19 recordsLinked to original sources
PubMed2007

Anaesthetic and cardiopulmonary effects of intramuscular morphine, medetomidine and ketamine administered to telemetered cats.

The quality and duration of anaesthesia, cardiorespiratory effects and recovery characteristics of a morphine, medetomidine, ketamine (MMK) drug combination were determined in cats. Six healthy, adult female cats were administered 0.2 mg/kg morphine sulphate, 60 microg/kg medetomidine hydrochloride, and 5 mg/kg ketamine hydrochloride intramuscularly. Atipamezole was administered intramuscularly at 120 min after MMK administration. Time to lateral recumbency, intubation, extubation and sternal recumbency were recorded. Cardiorespiratory variables and response to a noxious stimulus were recorded before and at 3 min and 10 min increments after drug administration until sternal recumbency. The time to lateral recumbency and intubation were 1.9+/-1.2 and 4.3+/-1.2 min, respectively. Body temperature and haemoglobin saturation with oxygen remained unchanged compared to baseline values throughout anaesthesia. Respiratory rate, tidal volume, minute volume, heart rate, and blood pressure were significantly decreased during anaesthesia compared to baseline values. One cat met criteria for hypotension (systolic blood pressure <90 mmHg). End tidal carbon dioxide increased during anaesthesia compared to baseline values. All but one cat remained non-responsive to noxious stimuli from 3 to 120 min. Time to extubation and sternal recumbency following atipamezole were 2.9+/-1.1 and 4.7+/-1.0 min, respectively. MMK drug combination produced excellent short-term anaesthesia and analgesia with minimal cardiopulmonary depression. Anaesthesia lasted for at least 120 min in all but one cat and was effectively reversed by atipamezole.

Analgesics, Opioid↗
PubMed2006

Evaluation of total intravenous anesthesia with propofol or ketamine-medetomidine-propofol combination in horses.

Objective-To compare the anesthetic and cardiorespiratory effects of total IV anesthesia with propofol (P-TIVA) or a ketamine-medetomidine-propofol combination (KMP-TIVA) in horses. Design-Randomized experimental trial. Animals-12 horses. Procedure-Horses received medetomidine (0.005 mg/kg [0.002 mg/lb], IV). Anesthesia was induced with midazolam (0.04 mg/kg [0.018 mg/lb], IV) and ketamine (2.5 mg/kg [1.14 mg/lb], IV). All horses received a loading dose of propofol (0.5 mg/kg [0.23 mg/lb], IV), and 6 horses underwent P-TIVA (propofol infusion). Six horses underwent KMP-TIVA (ketamine [1 mg/kg/h {0.45 mg/lb/h}] and medetomidine [0.00125 mg/kg/h {0.0006 mg/lb/h}] infusion; the rate of propofol infusion was adjusted to maintain anesthesia). Arterial blood pressure and heart rate were monitored. Qualities of anesthetic induction, transition to TIVA, and maintenance of and recovery from anesthesia were evaluated. Results-Administration of KMP IV provided satisfactory anesthesia in horses. Compared with the P-TIVA group, the propofol infusion rate was significantly less in horses undergoing KMP-TIVA (0.14 +/- 0.02 mg/kg/min [0.064 +/- 0.009 mg/lb/min] vs 0.22 +/- 0.03 mg/kg/min [0.1 +/- 0.014 mg/lb/min]). In the KMP-TIVA and P-TIVA groups, anesthesia time was 115 +/- 17 minutes and 112 +/- 11 minutes, respectively, and heart rate and arterial blood pressure were maintained within acceptable limits. There was no significant difference in time to standing after cessation of anesthesia between groups. Recovery from KMP-TIVA and P-TIVA was considered good and satisfactory, respectively. Conclusions and Clinical Relevance-In horses, KMP-TIVA and P-TIVA provided clinically useful anesthesia; the ketamine-medetomidine infusion provided a sparing effect on propofol requirement for maintaining anesthesia.

Anesthesia, Intravenous↗
PubMed2006

Effect of medetomidine on respiration and minimum alveolar concentration in halothane- and isoflurane-anesthetized dogs.

OBJECTIVE: To evaluate the effect of medetomidine on minimum alveolar concentration (MAC), respiratory rate, tidal volume, minute volume (V(M)), and maximum inspiratory occlusion pressure (IOCP(max)) in halothane- and isoflurane-anesthetized dogs. ANIMALS: 6 healthy adult dogs (3 males and 3 females). PROCEDURE: The MAC of both inhalants was determined before and 5, 30, and 60 minutes after administration of medetomidine (5 microg/kg, IV). Dogs were subsequently anesthetized by administration of halothane or isoflurane and administered saline (0.9% NaCl) solution IV or medetomidine (5 microg/kg, IV). Respiratory variables and IOCP(max) were measured at specific MAC values 15 minutes before and 5, 30, and 60 minutes after IV administration of medetomidine while dogs breathed 0% and 10% fractional inspired carbon dioxide (FICO2). Slopes of the lines for VM/FICO2 and IOCP(max)/FICO2 were then calculated. RESULTS: Administration of medetomidine decreased MAC of both inhalants. Slope of V(M)/FICO2 increased in dogs anesthetized with halothane after administration of medetomidine, compared with corresponding values in dogs anesthetized with isoflurane. Administration of medetomidine with a simultaneous decrease in inhalant concentration significantly increased the slope for V(M)/FICO2, compared with values after administration of saline solution in dogs anesthetized with halothane but not isoflurane. Values for IOCP(max) did not differ significantly between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Equipotent doses of halothane and isoflurane have differing effects on respiration that are most likely attributable to differences in drug effects on central respiratory centers. Relatively low doses of medetomidine decrease the MAC of halothane and isoflurane in dogs.

Anesthetics, Inhalation↗
PubMed2005

Characteristics of pain and response to analgesic treatment in dogs and cats examined at a veterinary teaching hospital emergency service.

OBJECTIVE: To estimate the prevalence and characteristics of pain in dogs and cats examined by an emergency service at a veterinary teaching hospital and evaluate the response of dogs and cats with signs of pain to analgesic treatment. DESIGN: Cross-sectional study. ANIMALS: 317 dogs and 112 cats. PROCEDURE: A questionnaire was used to categorize the characteristics of pain. The location, cause, and signs of pain were determined by obtaining a thorough history and conducting a physical examination. Pain was categorized by type (superficial somatic, deep somatic, or visceral), mechanism (inflammatory, neuropathic, or both), severity (mild, moderate, or severe), and duration. Evidence for primary or secondary hypersensitivity and hyposensitivity to manipulation was determined. The response to single or multiple analgesic drug administration was assessed. RESULTS: 179 (56%) dogs and 60 (54%) cats had signs of pain. In most of these dogs and cats, pain was classified as acute (< 24 hours' duration) and of moderate severity and was associated with primary hypersensitivity. Most dogs had deep somatic pain; most cats had visceral pain. Inflammation was the most common mechanism. One hundred nineteen (66%) dogs and 41 (68%) cats were treated with analgesic drugs. Analgesic treatment was considered effective in 73 (61%) dogs and 31 (76%) cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that moderate to severe acute somatic pain caused by inflammation is common in dogs and cats examined by an emergency service and that a combination of multiple analgesic drugs is more effective than any single analgesic drug in the treatment of pain in these dogs and cats.

Analgesics↗
PubMed2005

Pain management in ruminants.

Based on the available literature, the most important tool available in modern veterinary medicine is preemptive analgesia. Veterinarians must capture "opportunities" to prevent the onset of pain, prevent noxious stimuli or their perception, and limit the pain-stress-distress cascade that results in altered behavior and deviation from physiologic norms. Rational treatment of pain requires an appreciation of its consequences, a fundamental understanding of the mechanisms that are responsible for its production,and a practical appreciation of the analgesic drugs that are available. The goal of pain treatment should be to restore normal (physiologic) pain responses and to eliminate pathologic pain processes. In this context, pain therapy should be directed at the multiple mechanisms (multimodal therapy)responsible for its production, and analgesic therapies should be instituted before (preemptive therapy) pain is initiated (eg, surgery) whenever possible.

Analgesia↗
PubMed2005

Bispectral analysis of the electroencephalogram: a review of its development and use in anesthesia.

OBJECTIVE: To evaluate the different methodologies used to monitor anesthetic depth and to review the principles and potential applications of bispectral index (BIS) monitoring in veterinary anesthesia. DATABASES USED: Medline (1966 to present); Pubmed (mid-1960s to present); personal files. CONCLUSIONS: Current anesthetic monitoring techniques rely on indirect measures of corticocerebral arousal after a noxious stimulus. Some anesthetics and pre-anesthetics suppress responses that are used to gauge adequate hypnosis and analgesia. The BIS is a direct measure of corticocerebral activation and is inversely related to the degree of hypnosis. Dynamic changes in the BIS after a noxious stimulus may signify early nociceptive activation of the cerebral cortex and may be a useful marker of inadequate analgesia. However, application of this technique during the use of various drug combinations (i.e. clinical anesthesia) will require further research and understanding.

Anesthesia↗
PubMed2005

Anesthetic and cardiovascular effects of balanced anesthesia using constant rate infusion of midazolam-ketamine-medetomidine with inhalation of oxygen-sevoflurane (MKM-OS anesthesia) in horses.

The anesthetic sparring and cardiovascular effects produced by midazolam 0.8 mg/ml-ketamine 40 mg/ml-medetomidine 0.05 mg/ml (0.025 ml/kg/hr) drug infusion during sevoflurane in oxygen (MKM-OS) anesthesia was determined in healthy horses. The anesthetic sparring effects of MKM-OS were assessed in 6 healthy thoroughbred horses in which the right carotid artery was surgically relocated to a subcutaneous position. All horses were intubated and ventilated with oxygen using intermittent positive pressure ventilation (IPPV). The end-tidal concentration of sevoflurane (ET(SEV)) required to maintain surgical anesthesia was approximately 1.7%. Heart rate and mean arterial blood pressure averaged 23-41 beats/min and 70-112 mmHg, respectively. All horses stood between 23-44 min after the cessation of all anesthetic drugs. The cardiovascular effects of MKM-OS anesthesia were evaluated in 5 healthy thoroughbred horses ventilated using IPPV. Anesthesia was maintained for 4 hr at an ET(SEV) of 1.7%. Each horse was studied during left lateral (LR) and dorsal recumbency (DR) with a minimum interval between evaluations of 1 month. Cardiac output and cardiac index were maintained between 70-80% of baseline values during LR and 65-70% of baseline values during DR. Stroke volume was maintained between 75-85% of baseline values during LR and 60-70% of baseline values during DR. Systemic vascular resistance was not different from baseline values regardless of position. MKM-OS anesthesia may be useful for prolonged equine surgery because of its minimal cardiovascular depression in both of lateral and dorsal recumbency.

Anesthesia, Inhalation↗
PubMed2005

Comparisons of the effects of acupuncture, electroacupuncture, and transcutaneous cranial electrical stimulation on the minimum alveolar concentration of isoflurane in dogs.

OBJECTIVE: To compare the effects of acupuncture (AP), electroacupuncture (EA), and transcutaneous cranial electrical stimulation (TCES) with high-frequency intermittent currents on the minimum alveolar concentration (MAC) of isoflurane and associated cardiovascular variables in dogs. ANIMALS: 8 healthy adult female Beagles. PROCEDURE: Each dog was anesthetized with isoflurane on 4 occasions, allowing a minimum of 10 days between experiments. Isoflurane MAC values were determined for each dog without treatment (controls) and after treatment with AP and EA (AP points included the Large Intestine 4, Lung 7, Governing Vessel 20, Governing Vessel 14, San Tai, and Baihui) and TCES. Isoflurane MAC values were determined by use of noxious electrical buccal stimulation. Heart rate, mean arterial blood pressure (MAP), arterial blood oxygen saturation (Spo2) measured by use of pulse oximetry, esophageal body temperature, inspired and expired end-tidal isoflurane concentrations, end-tidal carbon dioxide concentration, and bispectral index (BIS) were monitored. Blood samples were collected for determination of plasma cortisol concentration. RESULTS: Mean +/- SD baseline MAC of isoflurane was 1.19 +/- 0.1%. Acupuncture did not significantly change MAC of isoflurane. Treatments with EA and TCES significantly lowered the MAC of isoflurane by 10.1% and 13.4%, respectively. The Spo2, heart rate, MAP, BIS, esophageal body temperature, and plasma cortisol concentration were not significantly different after AP, EA, TCES, and control treatments at any time interval. CONCLUSIONS AND CLINICAL RELEVANCE: Use of EA and TCES decreased MAC of isoflurane in dogs without inducing adverse hemodynamic effects. However, the reduction in isoflurane MAC by EA andTCES treatments was not considered clinically relevant.

Acupuncture Therapy↗
PubMed2004

Prevalence and characteristics of pain in dogs and cats examined as outpatients at a veterinary teaching hospital.

OBJECTIVE: To determine prevalence of pain among dogs and cats examined as outpatients at a veterinary teaching hospital and characteristics of pain in dogs and cats with evidence of pain. DESIGN: Cross-sectional study. ANIMALS: 1,153 dogs and 652 cats examined as outpatients at The Ohio State University during 2002. PROCEDURE: A questionnaire was administered to owners of all dogs and cats. For dogs and cats with evidence of pain, the cause, signs, anatomic location, type (superficial somatic, deep somatic, or visceral), duration, and severity of the pain and the principle mechanism (inflammatory, neuropathic, both, or unknown) responsible for the pain were determined on the basis of questionnaire responses and results of physical examination. The presence of primary hyperalgesia, secondary hyperalgesia, allodynia, and hyposensitivity was recorded. RESULTS: 231 (20%) dogs and 92 (14%) cats had evidence of pain. Dogs with evidence of pain were significantly older and heavier than dogs without. Cats with evidence of pain were significantly older than cats without. In most dogs and cats with evidence of pain, the pain was determined to be of short duration (< 7 days), of mild or moderate severity, somatic, associated with primary hyperalgesia, and inflammatory. Analgesic drugs were frequently administered to dogs with chronic pain, but were not always considered effective. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that mild or moderate pain associated with inflammation may be seen in dogs and cats examined as outpatients. Older, heavier dogs and older cats were more likely to have evidence of pain.

Age Factors↗
PubMed2004

Comparison of lactated Ringer's solution and a physiologically balanced 6% hetastarch plasma expander for the treatment of hypotension induced via blood withdrawal in isoflurane-anesthetized dogs.

OBJECTIVE: To compare the effects of lactated Ringer's solution (LRS) with those of a physiologically balanced 6% hetastarch plasma expander administered to isoflurane-anesthetized dogs with hypotension induced by blood withdrawal. ANIMALS: 12 healthy Beagles. PROCEDURE: Blood was withdrawn from isoflurane-anesthetized dogs (volume withdrawn measured) to a systolic arterial blood pressure (SAP) of 80 mm Hg. Six dogs each received either LRS or hetastarch solution (90 mL/kg/h, i.v.). Hemodynamic variables, pH, blood gas concentrations, PCV, serum electrolyte and total protein concentrations, and colloid osmotic pressure (COP) were determined at baseline, while SAP was 80 mm Hg, and after fluid treatment. The volume of fluid administered and rate of return of SAP to within 10% of baseline values were recorded. RESULTS: Mean +/- SD volume of blood withdrawn to decrease SAP to 80 mm Hg was 173 +/- 38 mL. Hemodynamic variables decreased after blood withdrawal but returned to baseline values more rapidly after infusion of a smaller volume of hetastarch solution, compared with the response to LRS infusion. Whereas PCV and serum total protein concentration decreased after administration of either solution, COP decreased only after administration of LRS. The total volume of hetastarch solution and LRS required to restore and maintain SAP to within 10% of baseline values was 1.1 +/- 0.9 and 4.4 +/- 1.7 times greater than the volume of blood removed, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with LRS infusion, smaller volumes of hetastarch solution normalized and maintained SAP without lowering COP in isoflurane-anesthetized dogs after blood withdrawal.

Analysis of Variance↗
PubMed2004

Effects of xylazine on canine coronary artery vascular rings.

OBJECTIVE: To determine the effects of xylazine on canine coronary artery smooth muscle tone. SAMPLE POPULATION: Hearts of 26 healthy dogs. PROCEDURE: Dogs were anesthetized with pentobarbital, and vascular rings of various diameters were prepared from the epicardial coronary arteries. Vascular rings were placed in tissue baths to which xylazine was added (cumulative concentrations ranging from 10(-10) to 10(-4) M), and changes in vascular ring tension were continuously recorded. Effects of the nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L NAME; 5 mM), the alpha1-adrenoceptor antagonist prazosin (10 mM), and the alpha2-adrenoceptor antagonist atipamezole (10 mM) on xylazine-induced changes in vascular ring tension were determined. Results were expressed as percentage of maximal contraction for each vascular ring preparation. RESULTS: Xylazine induced vasoconstriction of small (< 500-microm-diameter) and medium (500- to 1,000-microm-diameter) vascular rings but not of large (> 1,000-microm-diameter) rings. For large vascular rings, L-NAME, atipamezole, and prazosin did not significantly affect the contractile response to xylazine. For small vascular rings, the contractile response following addition of xylazine to rings treated with L-NAME was not significantly different from the contractile response following addition of xylazine to control rings, except at a xylazine concentration of 10(-6) M. Xylazine-induced vasoconstriction of small vascular rings was blocked by atipamezole, but the addition of prazosin had no effect on xylazine-induced vasoconstriction. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that xylazine increases smooth muscle tone of small canine coronary arteriesand that this effect is predominantly mediated by stimulation of alpha2adrenoceptors.

Analysis of Variance↗
PubMed2004

Effect of medetomidine on breathing and inspiratory neuromuscular drive in conscious dogs.

OBJECTIVE: To evaluate the effects of the alpha2-adrenoceptor agonist medetomidine on respiratory rate (RR), tidal volume (V(T)), minute volume (V(M)), and central respiratory neuromuscular drive as determined by inspiratory occlusion pressure (IOP) during increasing fractional inspired concentrations of carbon dioxide (FiCO2) in conscious dogs. ANIMALS: 6 healthy dogs (3 males and 3 females). PROCEDURE: Dogs were administered 0, 5, or 10 microg of medetomidine/kg i.v. We measured RR, V(T), V(M), and IOP for the first 0.1 second of airway occlusion (IOP0.1) during FiCO2 values of 0%, 2.5%, 5.0%, and 75% at 15 minutes before and 5, 30, and 60 minutes after administration of medetomidine. RESULTS: Increases in FiCO2 significantly increased RR, V(T), and V(M). The i.v. administration of 5 and 10 microg of medetomidine/kg significantly decreased RR and V(M) at 5, 30, and 60 minutes for FiCO2 values of 2.5% and 5.0% and at 30 and 60 minutes for an FiCO2 value of 75%. The IOP0.1 was decreased after 30 minutes only for an FiCO2 value of 7.5% in dogs administered 5 and 10 microg of medetomidine/kg. The IOP0.1 was decreased at 60 minutes after administration of 10 microg of medetomidine/kg for an FiCO2 value of 7.5%. CONCLUSIONS AND CLINICAL RELEVANCE: The i.v. administration of medetomidine decreases RR, V(M), and central respiratory drive in conscious dogs. Medetomidine should be used cautiously and with careful monitoring in dogs with CNS depression or respiratory compromise.

Adrenergic alpha-Agonists↗
PubMed2003

Analgesic, behavioral, and hemodynamic and respiratory effects of midsacral subarachnoidally administered ropivacaine hydrochloride in mares.

OBJECTIVE: To determine the analgesic, behavioral, hemodynamic and respiratory effects of midsacral subarachnoid administration of ropivacaine hydrochloride solution in mares. STUDY DESIGN: Randomized, blinded study. ANIMALS: Ten healthy mares, weighing from 470 to 560 kg. METHODS: Intravascular and subarachnoid catheters were placed after infiltration of the skin and subcutaneous tissues with 2% lidocaine. Ropivacaine (0.2%, 5 mL) or 0.9% NaCl was then administered subarachnoidally at the midsacral (S2-S3) vertebrae. Analgesia was determined by lack of sensory perception to electrical stimulation (>40 mA) and absence of response to needle pricks extending from coccygeal to S1 dermatomes. Numerical scores of sedation, change in pelvic limb position, sweating in analgesic zones, urination, behavior, response to noise, and compliance with restraint were determined. Two-way ANOVA with repeated measures and Dunnett's t-tests were used to evaluate differences between the listed numerical scores, and cardiovascular and respiratory variables before and during a 5-hour testing period. RESULTS: Subarachnoidally administered ropivacaine-induced variable analgesia extending bilaterally from the coccyx to S1, with minimal sedation and change in pelvic limb position in standing mares. Perineal analgesia was attained at 7.5 +/- 2.6 minutes and lasted for 218 +/- 44 minutes (mean +/- SD). Subarachnoid ropivacaine significantly reduced respiratory rates and did not change heart rate, rectal temperature, arterial blood pressure, PCV, arterial gas tensions (PaO2 and PaCO2), pH, and arterial standard bicarbonate and base excess from baseline. CONCLUSION AND CLINICAL RELEVANCE: Ropivacaine (0.2% solution, 5 mL 500 kg(-1)) can be administered subarachnoidally at midsacral (S2-S3) vertebrae to produce prolonged (>3 hours) bilateral perineal analgesia with minimal changes of behavior, and circulatory and respiratory disturbances in standing mares.

Amides↗
PubMed2003

Effects of morphine, lidocaine, ketamine, and morphine-lidocaine-ketamine drug combination on minimum alveolar concentration in dogs anesthetized with isoflurane.

OBJECTIVE: To determine the effects of constant rate infusion of morphine, lidocaine, ketamine, and morphine-lidocaine-ketamine (MLK) combination on end-tidal isoflurane concentration (ET-Iso) and minimum alveolar concentration (MAC) in dogs anesthetized with isoflurane and monitor depth of anesthesia by use of the bispectral index (BIS). ANIMALS: 6 adult dogs. PROCEDURE: Each dog was anesthetized with isoflurane on 5 occasions, separated by a minimum of 7 to 10 days. Individual isoflurane MAC values were determined for each dog. Reduction in isoflurane MAC, induced by administration of morphine (3.3 microg/kg/min), lidocaine (50 microg/kg/min), ketamine (10 microg/kg/min), and MLK, was determined. Heart rate, mean arterial blood pressure, oxygen saturation as measured by pulse oximetry (Spo2), core body temperature, and BIS were monitored. RESULTS: Mean +/- SD isoflurane MAC was 1.38 +/- 0.08%. Morphine, lidocaine, ketamine, and MLK significantly lowered isoflurane MAC by 48, 29, 25, and 45%, respectively. The percentage reductions in isoflurane MAC for morphine and MLK were not significantly different but were significantly greater than for lidocaine and ketamine. The Spo2, mean arterial pressure, and core body temperature were not different among groups. Heart rate was significantly decreased at isoflurane MAC during infusion of morphine and MLK. The BIS was inversely related to the ET-Iso and was significantly increased at isoflurane MAC during infusions of morphine and ketamine, compared with isoflurane alone. CONCLUSIONS AND CLINICAL RELEVANCE: Low infusion doses of morphine, lidocaine, ketamine, and MLK decreased isoflurane MAC in dogs and were not associated with adverse hemodynamic effects. The BIS can be used to monitor depth of anesthesia.

Analgesics, Opioid↗
PubMed2003

Comparison of the effect of propofol and sevoflurane on the urethral pressure profile in healthy female dogs.

OBJECTIVE: To compare the effects of propofol and sevoflurane on the urethral pressure profile in female dogs. ANIMALS: 10 healthy female dogs. PROCEDURE: Urethral pressure profilometry was performed in awake dogs, during anesthesia with sevoflurane at 1.5, 2.0, and 3.0% end-tidal concentration, and during infusion of propofol at rates of 0.4, 0.8, and 1.2 mg/kg/min. A consistent plane of anesthesia was maintained for each anesthetic protocol. Maximum urethral pressure, maximum urethral closure pressure, functional profile length, and functional area were measured. RESULTS: Mean maximum urethral closure pressure of awake dogs was not significantly different than that of dogs anesthetized with propofol at all infusion rates or with sevoflurane at 1.5 and 2.0% end-tidal concentration. Functional area in awake dogs was significantly higher than in anesthetized dogs. Functional area of dogs during anesthesia with sevoflurane at 3.0% end-tidal concentration was significantly lower than functional area for other anesthetic protocols. Individual differences in the magnitude of effects of propofol and sevoflurane on urethral pressures were observed. CONCLUSIONS AND CLINICAL RELEVANCE: Sevoflurane is an alternative to propofol for anesthesia in female dogs undergoing urethral pressure profilometry. Use of these anesthetics at appropriate administration rates should reliably distinguish normal from abnormal maximum urethral closure pressures and functional areas. Titration of anesthetic depth is a critical component of urodynamic testing.

Anesthetics, Inhalation↗
PubMed2003

Comparison of electroacupuncture and butorphanol on respiratory and cardiovascular effects and rectal pain threshold after controlled rectal distention in mares.

OBJECTIVE: To compare effects of electroacupuncture and butorphanol on hemodynamic and respiratory variables and rectal analgesia in mares after controlled rectal distention. ANIMALS: 8 healthy mares. PROCEDURE: Each horse received saline (0.9% NaCl) solution (0.01 mL/kg, IV; control treatment), butorphanol tartrate (0.1 mg/kg, IV), or 2 hours of electroacupuncture (EA) at acupoints Bladder 21, 25, and 27 on both sides of the vertebral column, Bai hui, and Stomach 36 (right side only). Order of treatments in each mare was randomized. At least 7 days elapsed between treatments. A balloon was inserted in the rectum of each mare, and controlled distention of the balloon (pressures of < or = 220 mm Hg) was used to measure nociceptive rectal pain threshold. Rectal temperature and cardiovascular and respiratory variables were measured before (baseline) and 5,15, 30, 60, 90, and 120 minutes after onset of each treatment. RESULTS: Butorphanol produced greater increases in rectal pain threshold, compared with EA (mean +/- SD, 214 +/- 24 vs 174 +/- 35 mm Hg of balloon pressure). Electroacupuncture produced minimal cardiovascular and respiratory changes. Although clinically not important, butorphanol produced moderate significant increases in heart and respiratory rates, arterial blood pressure, and rectal temperature and decreases in arterial oxygen tension. Arterial pH, carbon dioxide tension, bicarbonate concentrations, base excess, Hct, and concentration of total solids were not significantly different from baseline values after EA, butorphanol, and control treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture and butorphanol (0.1 mg/kg, IV) may provide useful rectal analgesia in horses.

Animals↗