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1.
OBJECTIVE: To determine the relationship between bispectral index (BIS) and minimum alveolar concentration (MAC) multiples of isoflurane after IM injection of medetomidine or saline (0.9% NaCl) solution in anesthetized dogs. ANIMALS: 6 dogs. PROCEDURE: Each dog was anesthetized 3 times with isoflurane. First, the MAC of isoflurane for each dog was determined by use of the tail clamp method. Second, anesthetized dogs were randomly assigned to receive an IM injection of medetomidine (8 microg x kg(-1)) or an equal volume of isotonic saline (0.9% NaCl) solution 30 minutes prior to beginning BIS measurements. Last, anesthetized dogs received the remaining treatment (medetomidine or isotonic saline solution). Dogs were anesthetized at each of 4 MAC multiples of isoflurane. Ventilation was controlled and atracurium (0.2 mg/kg followed by 6 microg/kg/min as a continuous infusion, IV) administered. After a 20-minute equilibration period at each MAC multiple of isoflurane, BIS data were collected for 5 minutes and median values of BIS calculated. RESULTS: BIS significantly decreased with increasing MAC multiples of isoflurane over the range of 0.8 to 2.0 MAC. Mean (+/- SD) MAC of isoflurane was 1.3 +/- 0.2%. During isoflurane-saline anesthesia, mean BIS measurements at 0.8, 1.0, 1.5, and 2.0 MAC were 65 +/- 8, 60 +/- 7 52 +/- 3, and 31 +/- 28, respectively. During isoflurane-medetomidine anesthesia, mean BIS measurements at 0.8, 1.0, 1.5, and 2.0 MAC were 77 +/- 4, 53 +/- 7, 31 +/- 24, and 9 +/- 20, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: BIS monitoring in dogs anesthetized with isoflurane has a predictive value in regard to degree of CNS depression. During isoflurane anesthesia, our results support a MAC-reducing effect of medetomidine.  相似文献   

2.
OBJECTIVE: To evaluate concomitant propofol and fentanyl infusions as an anesthetic regime, in Greyhounds. ANIMALS: Eight clinically normal Greyhounds (four male, four female) weighing 25.58 +/- 3.38 kg. DESIGN: Prospective experimental study. METHODS: Dogs were premedicated with acepromazine (0.05 mg/kg) by intramuscular (i.m.) injection. Forty five minutes later anesthesia was induced with a bolus of propofol (4 mg/kg) by intravenous (i.v.) injection and a propofol infusion was begun (time = 0). Five minutes after induction of anesthesia, fentanyl (2 microg/kg) and atropine (40 microg/kg) were administered i.v. and a fentanyl infusion begun. Propofol infusion (0.2 to 0.4 mg/kg/min) lasted for 90 minutes and fentanyl infusion (0.1 to 0.5 microg/kg/min) for 70 minutes. Heart rate, blood pressure, respiratory rate, end-tidal carbon dioxide, body temperature, and depth of anesthesia were recorded. The quality of anesthesia, times to return of spontaneous ventilation, extubation, head lift, and standing were also recorded. Blood samples were collected for propofol and fentanyl analysis at varying times before, during and after anesthesia. RESULTS: Mean heart rate of all dogs varied from 52 to 140 beats/min during the infusion. During the same time period, mean blood pressure ranged from 69 to 100 mm Hg. On clinical assessment, all dogs appeared to be in light surgical anesthesia. Mean times (+/- SEM), after termination of the propofol infusion, to return of spontaneous ventilation, extubation, head lift and standing for all dogs were 26 +/- 7, 30 +/- 7, 59 +/- 12, and 105 +/- 13 minutes, respectively. Five out of eight dogs either whined or paddled their forelimbs in recovery. Whole blood concentration of propofol for all eight dogs ranged from 1.21 to 6.77 microg/mL during the infusion period. Mean residence time (MRTinf) for propofol was 104.7 +/- 6.0 minutes, mean body clearance (Clb) was 53.35 +/- 0.005 mL/kg/min, and volume of distribution at steady state (Vdss) was 3.27 +/- 0.49 L/kg. Plasma concentration of fentanyl for seven dogs during the infusion varied from 1.22 to 4.54 ng/mL. Spontaneous ventilation returned when plasma fentanyl levels were >0.77 and <1.17 ng/mL. MRTinf for fentanyl was 111.3 +/- 5.7 minutes. Mean body clearance was 29.1 +/- 2.2 mL/kg/min and Vdss was 2.21 +/- 0.19 L/kg. CONCLUSION AND CLINICAL RELEVANCE: In Greyhounds which were not undergoing any surgical stimulation, total intravenous anesthesia maintained with propofol and fentanyl infusions induced satisfactory anesthesia, provided atropine was given to counteract bradycardia. Despite some unsatisfactory recoveries the technique is worth investigating further for clinical cases, in this breed and in mixed breed dogs.  相似文献   

3.
OBJECTIVE: To evaluate the effects of various drugs and drug combinations conventionally used for anesthesia on arytenoid cartilage motion during laryngoscopy in normal dogs. STUDY DESIGN: Experimental study. ANIMALS: Six large breed healthy dogs with no previous history of respiratory dysfunction. METHODS: Each dog was randomly assigned to a different injectable anesthetic protocol once weekly for 6 weeks, then in the 7th week all dogs were anesthetized with isoflurane. Videolaryngoscopy was performed and recorded starting immediately after induction until dogs could no longer be safely restrained for endoscopy. Video was digitized and 3 still images of maximal inspiration and expiration from the first 15 seconds (induction) and the last 15 seconds (recovery) were captured and imported into an image analysis software program. The height and area of the laryngeal ostium were measured in pixels. Normalization of the glottal gap area was performed using the formula (normalized glottal gap area (NGGA)=area in pixels/height(2)). ANOVA was performed on the NGGA of images collected at inspiration and expiration during induction and recovery. Fischer's exact test was performed when significance (P<.05) was found. RESULTS: Within each protocol, laryngeal motion (defined as change in NGGA) at induction was not significantly different from laryngeal motion measured at recovery. Additionally, no significant differences were found in arytenoid motion immediately after induction when anesthetic protocols were compared. Arytenoid motion before recovery was significantly greater with thiopental when compared with propofol (P=.046), ketamine+diazepam (P=.0098), acepromazine+thiopental (P=.0021), and acepromazine+propofol (P=.0065). No significant difference in arytenoid motion was seen immediately after induction or before recovery when acepromazine+butorphanol+ isoflurane and thiopental were compared. CONCLUSION: We concluded that intravenous thiopental given to effect is the best choice for assessing laryngeal function in dogs. Dogs premedicated with acepromazine with or without opioids that require further anesthetic restraint for laryngoscopy should be anesthetized with isoflurane administered by mask. CLINICAL RELEVANCE: Misdiagnosis of laryngeal paralysis during laryngoscopy can be avoided by selecting the anesthetic regimens with the least effect on arytenoid motion.  相似文献   

4.
OBJECTIVE: To evaluate bispectral index (BIS) values in pigs during anesthesia maintained with sevoflurane-fentanyl or propofol-fentanyl as a predictor of changes in hemodynamic parameters and duration of recovery from anesthesia. ANIMALS: 12 pigs. PROCEDURE: Pigs were randomly allocated to undergo 1 of 2 anesthetic regimens. Anesthesia was induced with propofol (2 mg/kg, i.v.); 6 pigs were administered sevoflurane via inhalation (1 minimum alveolar concentration [MAC] at a fresh gas flow rate of 3 L/min; group I), and 6 were administered propofol (11 mg/kg/h, i.v.; group II). All pigs received fentanyl (2.5 mg/kg, i.v., q 30 min). After abdominal surgery, pigs were allowed to recover from anesthesia. Cardiovascular variables and BIS values were recorded at intervals throughout the procedure; duration of recovery from anesthesia was noted. RESULTS: No correlation was established between arterial blood pressure and BIS and between heart rate and BIS. Mean BIS at discontinuation of administration of the anesthetic agent was greater in group-II pigs (65.2 +/- 10.6 minutes) than in group-I pigs (55.8 +/- 2.9 minutes). However, recovery from anesthesia was significantly longer in group II (59.80 +/- 2.52 minutes) than in group I (9.80 +/- 2.35 minutes). CONCLUSIONS AND CLINICAL RELEVANCE: In swine anesthetized with sevoflurane or propofol and undergoing abdominal surgery, the BIS value derived from an electroencephalogram at the end of anesthesia was not useful for predicting the speed of recovery from anesthesia. Moreover, BIS was not useful as a predictor of clinically important changes in arterial blood pressure and heart rate in those anesthetized pigs.  相似文献   

5.
Functional MRI as a tool to assess vision in dogs: the optimal anesthetic   总被引：3，自引：0，他引：3  
Functional magnetic resonance imaging (fMRI) is a recent advance in neuroimaging that provides a picture of brain activity with excellent spatial resolution. Current methods used to evaluate canine vision are poorly standardized and vulnerable to bias. Functional MRI may represent a valuable method of testing vision in dogs if the impacts of anesthesia on fMRI are understood. Six dogs were scanned during visual stimulation, each under three different anesthetic protocols (isoflurane, propofol, fentanyl/midazolam) to address the questions: (1) Can visually evoked fMR signals be reliably recorded in anesthetized dogs? and (2) Which anesthetic agent permits the least suppression of visually induced fMR signal in dogs? This study confirms that visual stimuli reliably elicit neural activity and fMR signal change in anesthetized dogs. No significant differences in images acquired under the three anesthetics were found, and there was no significant relationship between anesthetic dose and brain activity, within the range of doses used in this study. Images obtained during isoflurane anesthesia were more consistent between dogs than those obtained with the other two agents. This reduced variation may reflect the fact that inhalant anesthesia is more easily controlled than intravenous anesthesia under conditions associated with high field fMRI.  相似文献   

6.
The cardiovascular effects during 2 hours of anesthesia with either a continuous propofol infusion or isoflurane were compared in the same six healthy dogs. Dogs were randomly assigned to be anesthetized with either propofol (5 mg/kg, IV administered over 30 seconds, immediately followed by a propofol infusion beginning at 0.4 mg/kg/min), or isoflurane (2.0% end-tidal concentration). The propofol infusion was adjusted to maintain a light plane of anesthesia. Dogs anesthetized with propofol had higher values for systemic arterial pressure due to higher systemic vascular resistance. Dogs anesthetized with isoflurane had higher values for heart rate and mean pulmonary artery pressure. Cardiac index was not different between the two groups. Apnea and cyanosis were observed during induction of anesthesia with propofol. At the end of anesthesia the mean time to extubation for dogs anesthetized with either propofol or isoflurane was 13.5 min and 12.7 min, respectively. A continuous infusion of propofol (0.44 mg/kg/min) provided a light plane of anesthesia. Ventilatory support during continuous propofol infusion is recommended.  相似文献   

7.
OBJECTIVE: To determine induction characteristics and the minimum alveolar concentration (MAC) at which consciousness returned (MACawake) in dogs anesthetized with isoflurane or sevoflurane. ANIMALS: 20 sexually intact male Beagles. PROCEDURES: In experiment 1, 20 dogs were randomly assigned to have anesthesia induced and maintained with isoflurane or sevoflurane. The MAC at which each dog awoke in response to auditory stimulation (MACawake-noise) was determined by decreasing the end-tidal concentration by 0.1 volume (vol %) every 15 minutes and delivering a standard audible stimulus at each concentration until the dog awoke. In experiment 2, 12 dogs received the same anesthetic agent they were administered in experiment 1. After duplicate MAC determination, the end-tidal concentration was continually decreased by 10% every 15 minutes until the dog awoke from anesthesia (MACawake). RESULTS: Mean induction time was significantly greater for isoflurane-anesthetized dogs (212 seconds), compared with the sevoflurane-anesthetized dogs (154 seconds). Mean+/-SD MACawake-noise was 1.1+/-0.1 vol % for isoflurane and 2.0+/-0.2 vol % for sevoflurane. Mean MAC was 1.3+/-0.2 vol % for isoflurane and 2.1+/-0.6 vol % for sevoflurane, and mean MACawake was 1.0+/-0.1 vol % for isoflurane and 1.3+/-0.3 vol % for sevoflurane. CONCLUSIONS AND CLINICAL RELEVANCE: Sevoflurane resulted in a more rapid induction than did isoflurane. The MACawake for dogs was higher than values reported for both agents in humans. Care should be taken to ensure that dogs are at an appropriate anesthetic depth to prevent consciousness, particularly when single-agent inhalant anesthesia is used.  相似文献   

8.
OBJECTIVE: To characterize behavioral and physiological responses to short-term, unsupplemented intravenous (IV) anesthesia in healthy horses at high altitude (2240 m), and to test the hypothesis that the dose of butorphanol modifies the response of the horse to propofol anesthesia following xylazine pre-medication. STUDY DESIGN: Randomized prospective butorphanol dose cross-over experimental design. Animals Eight healthy horses, 13 +/- 6 (mean +/- SD) years of age, and weighing 523 +/- 26 kg. METHODS: Each horse was anesthetized three times with at least 3 weeks between each anesthesia. After collecting pre-drug data, xylazine (0.5 mg kg(-1)) was given IV. Five minutes later butorphanol was given IV according to a randomized order of three doses: 0.025, 0.05 and 0.075 mg kg(-1). Five minutes later, anesthesia was induced with propofol, 2 mg kg(-1) IV. Data on heart rate (HR) and respiratory rate (f(r)), mean arterial blood pressure, P(a)O(2), P(a)CO(2) and pH(a) were collected before, during and for 60 minutes following anesthesia, and quality of induction and recovery was scored. RESULTS: The pre-drug values for the three butorphanol groups did not differ. The combined pre-drug values from the 24 studies were HR, 33 +/- 7 beats minute(-1); f(r), 11 +/- 3 breaths minute(-1); P(a)O(2), 67 +/- 7 mmHg; P(a)CO(2), 36 +/- 4 mmHg; and pH(a), 7.42 +/- 0.04. Five minutes after anesthetic induction P(a)O(2) decreased and P(a)CO(2) increased 14.5 +/- 7.7 and 5.1 +/- 4.9 mmHg, respectively, but returned to pre-drug levels within 15 minutes of anesthetic recovery. There were no significant butorphanol dose-related differences in physiological results, anesthetic induction and recovery quality scores or recovery time. CONCLUSIONS AND CLINICAL RELEVANCE: Dose of butorphanol did not markedly influence study results. Notably, low P(a)O(2) values related to geographic location of study and general anesthesia indicates a narrow margin of error for hypoxemia-related complications in anesthetized horses breathing unsupplemented air at high altitude.  相似文献   

9.
ObjectiveTo compare isoflurane and propofol for maintenance of anesthesia and quality of recovery in client-owned dogs with intracranial disease undergoing magnetic resonance imaging (MRI).Study designProspective, randomized, clinical trial.AnimalsTwenty-five client-owned dogs with intracranial pathology, 13 females and 12 males, ages 11 months to 13 years, weighing between 3.0 and 48.0 kg.MethodsEach dog was randomly assigned to receive propofol or isoflurane for maintenance of anesthesia. All dogs were not premedicated, were administered propofol intravenously to effect for induction, intubated and mechanically ventilated to maintain an end-tidal carbon dioxide tension 30–35 mmHg (4.0–4.7 kPa). Temperature and cardiac output were measured pre- and post-MRI. Scores for mentation, neurological status, ease of maintenance, and recovery were obtained pre- and post-anesthesia. Pulse oximetry, end-tidal gases, arterial blood pressure, heart rate (HR) and requirements for dopamine administration to maintain mean arterial pressure (MAP) >60 mmHg were recorded throughout anesthesia.ResultsEnd-tidal isoflurane concentration was 0.73 ± 0.35% and propofol infusion rate was 292 ± 119 μg kg?1 minute?1. Cardiac index was higher, while HR was lower, with propofol than isoflurane in dogs younger than 5 years, but not in older dogs. Dogs maintained with isoflurane were 14.7 times more likely to require dopamine than propofol dogs. Mentation and maintenance scores and temperature were not different. MAP and diastolic arterial pressure were higher in the propofol group. Recovery scores were better with propofol, although times to extubation were similar. Change in neurological score from pre- to post-anesthesia was not different between treatments.ConclusionsDogs maintained with propofol during MRI had higher arterial pressures, decreased requirements for dopamine, and better recovery scores, compared to dogs maintained with isoflurane.Clinical relevancePropofol anesthesia offered cardiovascular and recovery advantages over isoflurane during MRI in dogs with intracranial disease in this study.  相似文献   

10.
OBJECTIVE: To compare the anesthetic index of sevoflurane with that of isoflurane in unpremedicated dogs. DESIGN: Randomized complete-block crossover design. ANIMALS: 8 healthy adult dogs. PROCEDURE: Anesthesia was induced by administering sevoflurane or isoflurane through a face mask. Time to intubation was recorded. After induction of anesthesia, minimal alveolar concentration (MAC) was determined with a tail clamp method while dogs were mechanically ventilated. Apneic concentration was determined while dogs were breathing spontaneously by increasing the anesthetic concentration until dogs became apneic. Anesthetic index was calculated as apneic concentration divided by MAC. RESULTS: Anesthetic index of sevoflurane (mean +/- SEM, 3.45 +/- 0.22) was significantly higher than that of isoflurane (2.61 +/- 0.14). No clinically important differences in heart rate; systolic, mean, and diastolic blood pressures; oxygen saturation; and respiratory rate were detected when dogs were anesthetized with sevoflurane versus isoflurane. There was a significant linear trend toward lower values for end-tidal partial pressure of carbon dioxide during anesthesia with sevoflurane, compared with isoflurane, at increasing equipotent anesthetic doses. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that sevoflurane has a higher anesthetic index in dogs than isoflurane. Sevoflurane and isoflurane caused similar dose-related cardiovascular depression, but although both agents caused dose-related respiratory depression, sevoflurane caused less respiratory depression at higher equipotent anesthetic doses.  相似文献   

11.
Propofol anesthesia.   总被引：3，自引：0，他引：3  
Although questions may still remain regarding the use of this unique sedative-hypnotic drug with anesthetic properties in high-risk patients, our studies have provided cardiopulmonary and neurological evidence of the efficacy and safety of propofol when used as an anesthetic under normal and selected impaired conditions in the dog. 1. Propofol can be safely and effectively used for the induction and maintenance of anesthesia in normal healthy dogs. Propofol is also a reliable and safe anesthetic agent when used during induced cardiovascular and pulmonary-impaired conditions without surgery. The propofol requirements to induce the safe and prompt induction of anesthesia prior to inhalant anesthesia with and without surgery have been determined. 2. The favorable recovery profile associated with propofol offers advantages over traditional anesthetics in clinical situations in which rapid recovery is important. Also, propofol compatibility with a large variety of preanesthetics may increase its use as a safe and reliable i.v. anesthetic for the induction and maintenance of general anesthesia and sedation in small animal veterinary practice. Although propofol has proven to be a valuable adjuvant during short ambulatory procedures, its use for the maintenance of general anesthesia has been questioned for surgery lasting more than 1 hour because of increased cost and marginal differences in recovery times compared with those of standard inhalant or balanced anesthetic techniques. When propofol is used for the maintenance of anesthesia in combination with a sedative/analgesic, the quality of anesthesia is improved as well as the ease with which the practitioner can titrate propofol; therefore, practitioners are able to use i.v. anesthetic techniques more effectively in their clinical practices. 3. Propofol can induce significant depression of respiratory function, characterized by a reduction in the rate of respiration. Potent alpha 2 sedative/analgesics (e.g., xylazine, medetomidine) or opioids (e.g., oxymorphone, butorphanol) increase the probability of respiratory depression during anesthesia. Appropriate consideration of dose reduction and speed of administration of propofol reduces the degree of depression. Cardiovascular changes induced by propofol administration consist of a slight decrease in arterial blood pressures (systolic, mean, diastolic) without a compensatory increase in heart rate. Selective premedicants markedly modify this characteristic response. 4. When coupled with subjective responses to painful stimuli, EEG responses during propofol anesthesia provide clear evidence that satisfactory anesthesia has been achieved in experimental dogs. When propofol is used as the only anesthetic agent, a higher dose is required to induce an equipotent level of CNS depression compared with the situation when dogs are premedicated. 5. The propofol induction dose requirement should be appropriately decreased by 20% to 80% when propofol is administered in combination with sedative or analgesic agents as part of a balanced technique as well as in elderly and debilitated patients. As a general recommendation, the dose of propofol should always be carefully titrated against the needs and responses of the individual patient, as there is considerable variability in anesthetic requirements among patients. Because propofol does not have marked analgesic effects and its metabolism is rapid, the use of local anesthetics, nonsteroidal anti-inflammatory agents, and opioids to provide postoperative analgesia improves the quality of recovery after propofol anesthesia. 6. The cardiovascular depressant effects of propofol are well tolerated in healthy animals, but these effects may be more problematic in high-risk patients with intrinsic cardiac disease as well as in those with systemic disease. In hypovolemic patients and those with limited cardiac reserve, even small induction doses of propofol (0.75-1.5 mg/kg i.v.) can produce profound hypotens  相似文献   

12.
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.  相似文献   

13.
Propofol was used as an induction agent of general anesthesia in 77 dogs and 64 cats, all client owned, for a variety of surgeries/treatments or diagnostic procedures. The mean intravenous doses of propofol required to achieve endotracheal intubation in dogs and cats were 6.5 +/- 1.4 mg/kg and 10.1 +/- 2.8 mg /kg, respectively. Most of the animals could be induced to anesthesia smoothly by the administration of propofol with a high incidence of apnea. Propofol is a clinically valuable anesthetic induction agent in both dogs and cats, however, care must be taken for apnea.  相似文献   

14.
OBJECTIVE: To determine the effect of morphine administered prior to anesthesia on the incidence of gastroesophageal reflux (GER) in dogs during the subsequent anesthetic episode. ANIMALS: 90 dogs (30 dogs/group). PROCEDURE: The randomized prospective clinical study included healthy dogs with no history of vomiting. Dogs were scheduled to undergo elective orthopedic surgery. Food was withheld for (mean+/-SD) 17.8+/-4.1 hours prior to induction of anesthesia. The anesthetic protocol included acepromazine maleate, thiopental, and isoflurane. Dogs were randomly selected to receive morphine at various dosages (0, 0.22, or 1.10 mg/kg, IM) concurrent with acepromazine administration prior to induction of anesthesia. A sensor-tipped catheter was used to measure esophageal pH, and GER was defined as a decrease in pH to < 4 or an increase to > 7.5. RESULTS: 40 dogs had acidic reflux, and 1 had biliary reflux. Proportions of dogs with GER were 8 of 30 (27%), 15 of 30 (50%), and 18 of 30 (60%) for morphine dosages of 0, 0.22, and 1.10 mg/kg, respectively. Mean duration of GER was 91.4+/-56.8 minutes. There was no significant association between GER and age, weight, vomiting after preanesthetic medication, administration of antimicrobials, or start of surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Most healthy dogs vomit after a large dose of morphine, but vomiting does not increase the likelihood of GER during the subsequent anesthetic episode. Administration of morphine prior to anesthesia substantially increases the incidence of GER during the subsequent anesthetic episode.  相似文献   

15.
OBJECTIVE: To compare the cardiopulmonary effects of anesthesia maintained by continuous infusion of ketamine and propofol with anesthesia maintained by inhalation of sevoflurane in goats undergoing magnetic resonance imaging. ANIMALS: 8 Saanen goats. PROCEDURES: Goats were anesthetized twice (1-month interval) following sedation with midazolam (0.4 mg/kg, IV). Anesthesia was induced via IV administration of ketamine (3 mg/kg) and propofol (1 mg/kg) and maintained with an IV infusion of ketamine (0.03 mg/kg/min) and propofol (0.3 mg/kg/min) and 100% inspired oxygen (K-P treatment) or induced via IV administration of propofol (4 mg/kg) and maintained via inhalation of sevoflurane in oxygen (end-expired concentration, 2.3%; 1X minimum alveolar concentration; SEVO treatment). Cardiopulmonary and blood gas variables were assessed at intervals after induction of anesthesia. RESULTS: Mean +/- SD end-expired sevoflurane was 2.24 +/- 0.2%; ketamine and propofol were infused at rates of 0.03 +/- 0.002 mg/kg/min and 0.29 +/- 0.02 mg/kg/min, respectively. Overall, administration of ketamine and propofol for total IV anesthesia was associated with a degree of immobility and effects on cardiopulmonary parameters that were comparable to those associated with anesthesia maintained by inhalation of sevoflurane. Compared with the K-P treatment group, mean and diastolic blood pressure values in the SEVO treatment group were significantly lower at most or all time points after induction of anesthesia. After both treatments, recovery from anesthesia was good or excellent. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ketamine-propofol total IV anesthesia in goats breathing 100% oxygen is practical and safe for performance of magnetic resonance imaging procedures.  相似文献   

16.
OBJECTIVE: To determine whether maintenance of anesthesia with halothane or sevoflurane is associated with a lower incidence of gastroesophageal reflux (GER) than the use of isoflurane in dogs undergoing orthopedic surgery. ANIMALS: 90 dogs. PROCEDURES: Dogs were evaluated during elective orthopedic surgery. Dogs with a history of vomiting or that had received any drugs that would alter gastrointestinal tract function were excluded from the study. The anesthetic protocol used was standardized to include administration of acepromazine maleate and morphine prior to induction of anesthesia with thiopental. Dogs were allocated to receive halothane, isoflurane, or sevoflurane to maintain anesthesia. A sensor-tipped catheter was placed to measure esophageal pH during anesthesia. Gastroesophageal reflux was defined as an esophageal pH < 4 or > 7.5. RESULTS: 51 dogs had 1 or more episodes of acidic GER during anesthesia. Reflux was detected in 14 dogs receiving isoflurane, 19 dogs receiving halothane, and 18 dogs receiving sevoflurane. In dogs with GER, mean +/- SD time from probe placement to onset of GER was 36 +/- 65 minutes and esophageal pH remained < 4 for a mean of 64% of the measurement period. There was no significant association between GER and start of surgery or moving a dog on or off the surgery table. Dogs that developed GER soon after induction of anesthesia were more likely to regurgitate. CONCLUSIONS AND CLINICAL RELEVANCE: Maintenance of anesthesia with any of the 3 commonly used inhalant agents is associated with a similar risk for development of GER in dogs.  相似文献   

17.
Fifty-eight foals were divided into two groups for study of aspects of the clinical anesthetic management of foals and to characterize effects of halothane (n = 30) and isoflurane (n = 28) in foals. There were no significant differences (P greater than 0.05) in the demographics of the two groups. Results of hemograms and biochemical analysis of venous blood samples before and after anesthesia were either not influenced or only mildly (clinically unimportant) affected by either agent. Like adult horses, foals have an increased PaCO2 when anesthetized with inhaled anesthetics. We could detect no difference in the magnitude of increase in PaCO2 with either anesthetic. Anesthetic induction and recovery was most rapid with isoflurane. The quality of induction and recovery was similarly acceptable with either agent. Heart rate during isoflurane was not significantly different from conscious conditions but during halothane, heart rate was significantly less than control except at 91-120 min when statistical significance was not detected. These results support the clinical impression that foals can be safely and reliably anesthetized with either agent.  相似文献   

18.
OBJECTIVE: To demonstrate the effect of anesthesia and surgery on serum ionized magnesium and ionized calcium concentrations in clinical canine and feline patients. ANIMALS: 37 client-owned dogs, ASA PS I-III and 10 client-owned cats, ASA PS I, all receiving anesthesia for elective or emergent surgery at a Veterinary Teaching Hospital. MATERIALS AND METHODS: Plasma ionized and serum total magnesium, and plasma ionized calcium were measured prior to and after a group-standardized anesthetic protocol. RESULTS: Regardless of pre-operative medication (hydromorphone or butorphanol), anesthetic induction (thiopental or lidocaine/hydromorphone/diazepam (LHD) and propofol combination), or type of surgical procedure (peripheral surgery or laparotomy), post-operative plasma ionized calcium concentration decreased in all groups of dogs, while post-operative plasma ionized magnesium increased in all groups, although the changes were not always significant. The dogs who were induced with an LHD and propofol technique had a greater increase in ionized magnesium (0.36 +/- 0.07 to 0.42 +/- 0.07 mmol L(-1)) than the group in which anesthesia was induced with thiopental (0.41 +/- 0.07 to 0.42 +/- 0.07 mmol L(-1), p = 0.009). The cats showed similar changes in ionized magnesium and ionized calcium, and also had a significant increase in serum total magnesium (2.17 +/- 0.20 to 2.31 +/- 0.25 mg dL(-1), p = 0.009) CONCLUSIONS, CLINICAL RELEVANCE: A post-operative decrease in ionized calcium was demonstrated in healthy animals, as well as an increase in ionized or total magnesium after various anesthetic protocols and surgeries. These changes, while statistically significant, do not appear to be clinically significant, as values remained within reference ranges at all times.  相似文献   

19.
OBJECTIVE: To evaluate renal effects of carprofen in healthy dogs following general anesthesia. DESIGN: Randomized clinical trial. ANIMALS: 10 English hound dogs (6 females and 4 males). PROCEDURE: Dogs were randomly assigned to control (n = 5) or carprofen (5) groups. Anesthesia was induced with propofol (6 to 8 mg/kg [2.7 to 3.6 mg/lb] of body weight, i.v.) and maintained with isoflurane (end-tidal concentration, 2.0%). Each dog underwent two 60-minute anesthetic episodes with 1 week between episodes, and mean arterial blood pressure was maintained between 60 and 90 mm Hg during each episode. Dogs in the carprofen group received carprofen (2.2 mg/kg [1 mg/lb], p.o.) at 9:00 AM and 6:00 PM the day before and at 7:00 AM the day of the second anesthetic episode. Glomerular filtration rates (GFR) were determined during each anesthetic episode by use of renal scintigraphy. Serum creatinine and BUN concentrations and the urine gamma-glutamyltransferase-to-creatinine concentration (urine GGT:creatinine) ratio were determined daily for 2 days before and 5 days after general anesthesia. RESULTS: Significant differences were not detected in BUN and serum creatinine concentrations, urine GGT:creatinine ratio, and GFR either between or within treatment groups over time. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen did not significantly alter renal function in healthy dogs anesthetized with propofol and isoflurane. These results suggest that carprofen may be safe to use for preemptive perioperative analgesia, provided that normal cardiorespiratory function is maintained.  相似文献   

20.
Objective- This study evaluates the clinical usefulness and anesthetic effect of propofol, and compares these effects with those of xylazine-ketamine-halothane anesthesia in sheep.
Study Design- Prospective, randomized, clinical trial. Animals or Sample Population- Fourteen healthy adult male sheep.
Methods- Sheep were randomly assigned to two different drug regimens: (1) Bolus injection of propofol (3 mg/kg, intravenously [IV]) followed by continuous intravenous infusion and (2) xylazine (0.11 mg/kg, IV) and ketamine (2.2 mg/kg, IV) for induction followed by halothane anesthesia. Heart rate, respiratory rate, and arterial blood pressures were monitored during anesthesia. Venous blood samples were collected for blood gas analysis. Quality of induction and recovery were also recorded.
Results- The average dose of propofol used to induce and maintain anesthesia was 6.63 ±2.06 mg/kg and 29.3 ±11.7 mg/kg/hr (0.49 ±0.20 mg/kg/min), respectively. The duration of propofol anesthesia was 45.3 ±13.2 minutes and recovery to standing occurred in 14.7 ±5.7 minutes. Sheep receiving xylazine-ketamine-halothane were anesthetized for 35.9 ±4.0 minutes and recovery to standing occurred within 28.5 ±7.5 minutes. Sheep anesthetized with propofol had a significantly higher heart rate, diastolic blood pressure and Pvo2, and a lower Pvco2 at 30 minutes and lower BE at 15 and 30 minutes than sheep anesthetized with xylazine-ketamine-halothane.
Conclusions- Propofol anesthesia was characterized by a smooth induction, effective surgical anesthesia and rapid recovery which was comparable to anesthesia with xylazine-ketamine-halothane.
Clinical Relevance- Propofol may be indicated in situations when it is desirable to maintain anesthesia with an intravenous infusion followed by a rapid recovery in healthy sheep.  相似文献   

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