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1.
Eighty-five thoroughbred racehorses with various types of fracture were subjected to arthroscopic surgery (44 horses) or internal fixation (41 horses) under sevoflurane anesthesia. The mean end-tidal sevoflurane concentration during anesthesia ranged from 2.5 to 2.8%. PaCO2 was maintained between 50 and 65 mmHg by controlled ventilation. The mean arterial blood pressure was maintained above 65 mmHg by infusion of dobutamine and fluids, however, heart rate significantly increased with time. Recovery from anesthesia was calm and smooth in almost all cases. No apparent complication was observed during and after anesthesia in all cases. Therefore, sevoflurane anesthesia is considered to be safe and useful for orthopedic surgery in racehorses.  相似文献   

2.
OBJECTIVE: To determine the minimum anesthetic concentration for sevoflurane and effects of various multiples of minimum anesthetic concentration on arterial pressure and heart rate during controlled ventilation in chickens. STUDY DESIGN: Prospective experimental study. ANIMALS: Seven healthy chickens, 6 to 8 months old, weighing 1.6 to 3.4 kg. METHODS: A rebreathing, semiclosed anesthetic circuit was used. Anesthesia was induced by mask with sevoflurane in oxygen. Each chicken was endotracheally intubated, then controlled ventilation was started and the end-tidal CO2 partial pressure was maintained at 30 to 40 mm Hg. Body temperature was maintained at 39.5 degrees to 41.0 degrees C. The inspired and end-tidal sevoflurane concentration were monitored with a multigas monitor. Minimum anesthetic concentration was determined as the minimal end-tidal sevoflurane concentration which prevented gross purposeful movement in response to clamping a toe for 1 minute. After the determination, the cardiovascular effects of sevoflurane at 1.0, 1.5, and 2.0 times the minimum anesthetic concentration were determined. RESULTS: The minimum anesthetic concentration for sevoflurane was 2.21% + 0.32% (mean +/- SD). Mean arterial pressure and heart rate at minimum anesthetic concentration were 84 +/- 13 mm Hg and 150 +/- 58 beats/min, respectively. There was a dose-dependent decrease in arterial pressure. The heart rate did not change significantly over the range 1 to 2 x minimum anesthetic concentration. No cardiac arrhythmias developed throughout the experiments. CONCLUSIONS AND CLINICAL RELEVANCE: The minimum anesthetic concentration for sevoflurane in chickens was within the range of minimum alveolar concentration reported in mammals. When the concentration of sevoflurane is increased during controlled ventilation in chickens, decrease in arterial pressure should be expected.  相似文献   

3.
Fourteen adult beavers (Castor canadensis) weighing 16.5 +/- 4.14 kg (mean +/- SD) were anesthetized for surgical implantation of radio telemetry devices. Beavers were anesthetized with diazepam (0.1 mg/kg) and ketamine (25 mg/kg) administered IM, which provided smooth anesthetic induction and facilitated tracheal intubation. Anesthesia was maintained with halothane in oxygen via a semiclosed circle anesthetic circuit. Values for heart rate, respiratory rate, esophageal temperature, direct arterial blood pressure, end-tidal halothane concentration, and end-tidal CO2 tension were recorded every 15 minutes during the surgical procedure. Arterial blood samples were collected every 30 minutes to determine pH, PaO2, and PaCO2. Values for plasma bicarbonate, total CO2, and base excess were calculated. Ventilation was spontaneous in 7 beavers and controlled to maintain normocapnia (PaCO2 approx 40 mm of Hg) in 7 others. Vaporizer settings were adjusted to maintain a light surgical plane of anesthesia. Throughout the surgical procedure, all beavers had mean arterial pressure less than 60 mm of Hg and esophageal temperature less than 35 C. Mean values for arterial pH, end-tidal CO2, PaO2, and PaCO2 were significantly (P less than 0.05) different in spontaneously ventilating beavers, compared with those in which ventilation was controlled. Respiratory acidosis during halothane anesthesia was observed in spontaneously ventilating beavers, but not in beavers maintained with controlled ventilation. All beavers recovered unremarkably from anesthesia.  相似文献   

4.
The effects of 1.0, 1.5, and 2.0 minimum alveolar concentration (MAC) of sevoflurane on hemodynamic, pulmonary and blood chemistry variables were measured during spontaneous and controlled ventilation in healthy horses. Sevoflurane was the only anesthetic drug administered to the horses. In a dose-dependent manner, sevoflurane significantly decreased ( P <.05) mean arterial blood pressure, cardiac output, and stroke volume. There was a progressive decrease in peripheral vascular resistance and an increase in heart rate as the concentration of sevoflurane was increased, but the differences were not significant. During spontaneous ventilation there was a dose-dependent decrease in respiratory rate that caused a decrease in the minute volume. As the dose of sevoflurane increased, the arterial carbon dioxide tension also increased ( P <.05). All blood chemistries remained within normal limits. Recovery from anesthesia was without incident. In conclusion, sevoflurane induces a dose-dependent decrease in hemodynamic variables and pulmonary function in horses that is not greatly different from that of other approved inhalant anesthetics.  相似文献   

5.
The purpose of this study was to investigate the cardiopulmonary influences of sevoflurane in oxygen at two anaesthetic concentrations (1.5 and 2 MAC) during spontaneous and controlled ventilation in dogs. After premedication with fentany-droperidol (5 microg/kg and 0.25 mg/kg intramuscularly) and induction with propofol (6 mg/kg intravenously) six dogs were anaesthetized for 3 h. Three types of ventilation were compared: spontaneous ventilation (SpV), intermittent positive pressure ventilation (IPPV), and positive end expiratory pressure ventilation (PEEP, 5 cm H2O). Heart rate, haemoglobin oxygen saturation, arterial blood pressures, right atrial and pulmonary arterial pressures, pulmonary capillary wedge pressure and cardiac output were measured. End tidal CO2%, inspiratory oxygen fraction, respiration rate and tidal volume were recorded using a multi-gas analyser and a respirometer. Acid-base and blood gas analyses were performed. Cardiac index, stroke volume, stroke index, systemic and pulmonary vascular resistance, left and right ventricular stroke work index were calculated. Increasing the MAC value during sevoflurane anaesthesia with spontaneous ventilation induced a marked cardiopulmonary depression; on the other hand, heart rate increased significantly, but the increases were not clinically relevant. The influences of artificial respiration on cardiopulmonary parameters during 1.5 MAC sevoflurane anaesthesia were minimal. In contrast, PEEP ventilation during 2 MAC concentration had more pronounced negative influences, especially on right cardiac parameters. In conclusion, at 1.5 MAC, a surgical anaesthesia level, sevoflurane can be used safely in healthy dogs during spontaneous and controlled ventilation (IPPV and PEEP of 5 cm H2O).  相似文献   

6.
The minimal anesthetic concentration (MAC) for isoflurane was determined during spontaneous ventilation in nine male Peking ducks (7 to 12 weeks of age; 3.0 +/- 0.4 kg). While each bird was awake, arterial blood was collected for analysis of pH, PaCO2, and PaO2. After anesthesia was induced with isoflurane in oxygen, MAC was determined for isoflurane in each bird during spontaneous ventilation in a manner similar to MAC determinations in mammals. Pulmonary dose-response data were collected at 1 MAC and 1.5 MAC. Anesthetic index (Al; an index of anesthetic-induced apnea) was calculated from ducks that became apneic. The MAC for isoflurane was 1.30 +/- 0.23% (mean +/- SD). There was a dose-dependent decrease in ventilation as evidenced by a statistically significant increase in PaCO2. Apnea or unacceptable hypercarbia (PaCO2 greater than 110 mm Hg), or both, were common occurrences at end-tidal isoflurane concentrations greater than 1.5 MAC. Anesthetic index calculated from four ducks was 1.65 +/- 0.13 (mean +/- SEM). There was no significant difference between the means of either heart rate or mean arterial blood pressure in birds at 1.0 and 1.5 MAC.  相似文献   

7.
The anesthetic potency and cardiopulmonary effects of sevoflurane were compared with those of isoflurane and halothane in goats. The (mean +/- SD) minimal alveolar concentration (MAC) was 0.96 +/- 0.12% for halothane, 1.29 +/- 0.11% for isoflurane, and 2.33 +/- 0.15% for sevoflurane. Cardiopulmonary effects of sevoflurane, halothane and isoflurane were examined at end-tidal concentrations equivalent to 1, 1.5 and 2 MAC during either spontaneous or controlled ventilation (SV or CV). During SV, there were no significant differences in respiration rate, tidal volume and minute ventilation between anesthetics. Dose-dependent decreases in both tidal volume and minute ventilation induced by halothane were greater than those by either sevoflurane or isoflurane. Hypercapnia and acidosis induced by sevoflurane were not significantly different from those by either isoflurane or halothane at 1 and 1.5 MAC, but were less than those by halothane at 2 MAC. There was no significant difference in heart rate between anesthetics during SV and CV. During SV, all anesthetics induced dose-dependent decreases in arterial pressure, rate pressure product, systemic vascular resistance, left ventricular minute work index and left ventricular stroke work index. Systemic vascular resistance with isoflurane at 2 MAC was lower than that with sevoflurane. During CV, sevoflurane induced dose-dependent circulatory depression (decreases in arterial pressure, cardiac index, rate pressure product, systemic vascular resistance, left ventricular minute work index and right ventricular minute work index), similar to isoflurane. Halothane did not significantly alter systemic vascular resistance from 1 to 2 MAC.  相似文献   

8.
BACKGROUND: Carbon dioxide (CO2) embolism is a possible complication of capnoperitoneum during laparoscopic surgery. Experimentally induced venous CO2 embolism has been studied in pigs. In this paper we report a case of spontaneous CO2 embolism. OBSERVATIONS: A 4-month-old Large White pig weighing 20 kg underwent experimental laparoscopic surgery under general anaesthesia. Monitoring consisted of pulse oximetry, capnography, airway pressure, electrocardiography, invasive arterial and central venous blood pressures, and arterial blood-gas analysis. Shortly after the start of laparoscopy and onset of CO2 insufflation, sudden decreases in end-tidal CO2 (Pe'CO2), haemoglobin saturation of oxygen (SpO2), systolic arterial blood pressure and heart rate were observed. Airway pressure increased and pulmonary compliance decreased simultaneously. Insufflation was immediately discontinued and epinephrine (2 mg IV), atropine (0.5 mg IV) and a 50 mL bolus of a polygeline solution were administered without effect. At this time arterial blood-gas analysis revealed a pH of 7.29 and a PaCO2 of 6.8 kPa (51.2 mmHg); PaO2 was 26.6 kPa (199.5 mmHg). After 4 minutes asystole occurred. CONCLUSIONS: The sudden decrease of Pe'CO2 and lung compliance combined with the sudden decrease in systolic blood pressure, heart rate and a poor response to resuscitation suggest a case of fatal gaseous venous embolism.  相似文献   

9.
Cardiopulmonary effects of halothane anesthesia in cats   总被引：2，自引：0，他引：2  
The cardiopulmonary effects of 2 planes of halothane anesthesia (halothane end-tidal concentrations of 1.78% [light anesthesia] and 2.75% [deep anesthesia]) and 2 ventilatory modes (spontaneous ventilation [SV] or mechanically controlled ventilation [CV]) were studied in 8 cats. Anesthesia was induced and maintained with halothane in O2 only, and each cat was administered each treatment according to a Latin square design. Cardiac output, arterial blood pressure, pulmonary arterial pressure, heart rate, respiratory frequency, and PaO2, PaCO2, and pH were measured during each treatment. Stroke volume, cardiac index, and total peripheral resistance were calculated. A probability value of less than 5% was accepted as significant. In the cats, cardiac output, cardiac index, and stroke volume were reduced by deep anesthesia and CV, although only the reduction attributable to CV was significant. Systemic arterial pressure was significantly reduced by use of deep anesthesia and CV. Respiratory frequency was significantly lower during CV than during SV. Arterial PO2 was significantly decreased at the deeper plan of anesthesia, compared with the lighter plane. At the deeper plane of anesthesia, arterial PCO2 and pulmonary arterial pressure were significantly lower during CV than during SV. The deeper plane of halothane anesthesia depressed cardiopulmonary function in these cats, resulting in hypotension and considerable hypercapnia. Compared with SV, CV significantly reduced circulatory variables and should be used with care in cats. Arterial blood pressure was judged to be more useful for assessing anesthetic depth than was heart rate or respiratory frequency.  相似文献   

10.
OBJECTIVE: To compare haemodynamic and respiratory variables during isoflurane-fentanyl (IF) and propofol-fentanyl (PF) anaesthesia for surgery in injured cats. STUDY DESIGN: Prospective, randomized, controlled clinical study. ANIMALS: Thirty-three client-owned injured cats undergoing orthopaedic surgery. MATERIALS AND METHODS: Pre-anaesthetic medication was intravenous midazolam 1 mg kg(-1), butorphanol 0.4 mg kg(-1) and ketamine 2 mg kg(-1). Anaesthesia was induced with propofol (P) and maintained with either: (a) a continuous rate infusion (CRI) of fentanyl (F) 0.02 mg kg(-1) hour(-1) and isoflurane (initial end-tidal concentration of 1%), (b) a fentanyl CRI (dose as before) and sevoflurane (initial end-tidal concentration of 2%) or (c) a CRI of propofol (12 mg kg(-1) hour(-1)). All three techniques were given to effect until surgical anaesthesia was achieved. Heart rate and rhythm (ECG), mean arterial blood pressure, respiratory rate, tidal volume and end-tidal CO(2) concentration were recorded. Venous blood gas analysis was performed before and after sedation, and at the end of anaesthesia. Blood chemistry and blood cell counts were assessed before, at the end of, and 24 hours after anaesthesia. The variables recorded from cats anaesthetized with IF and PF were compared. RESULTS: Mean end-expiratory isoflurane concentration was 1.19 +/- 0.19%. The propofol infusion rate was 11.4 +/- 0.8 mg kg(-1) hour(-1). No significant differences between the two groups in heart rate were identified; no cardiac dysrhythmias were recorded. Mean arterial blood pressure was significantly lower in IF cats during skin incision (p = 0.01), during surgery without intense surgical stimulation (p < 0.01) and during surgery with intense surgical stimulation (p = 0.01). Nine of 11 cats in the IF group were markedly hypotensive (34-49 mmHg) while seven of 11 cats in group PF were mildly hypotensive (49-59 mmHg). One of 11 cats in group IF and nine of 11 cats in group PF required intermittent positive pressure ventilation (IPPV) to maintain end-tidal CO(2) levels below 6.66 kPa (50 mmHg). CONCLUSION AND CLINICAL RELEVANCE: Despite the necessity to ventilate the lungs of cats in the PF group, arterial blood pressure was better maintained. Propofol-fentanyl anaesthesia is better for surgery in injured cats providing the means to impose IPPV are available.  相似文献   

11.
The cardiopulmonary effects of capnoperitoneum were investigated in 8 spontaneously breathing, young adult female cats undergoing laparoscopic pancreatic biopsy (intra-abdominal pressure 12 mmHg). Cats were premedicated with acepromazine and hydromorphone, induced with ketamine and diazepam, and maintained using an end-tidal isoflurane concentration of 1.13% in 100% oxygen. Direct systemic arterial blood pressure, heart and respiratory rates, end-tidal carbon dioxide (CO(2)), and isoflurane were recorded every 5 min before insufflation (baseline), during insufflation of the abdomen with CO(2), and following desufflation. Arterial blood samples were drawn at baseline, at 10 and 30 min of insufflation, and 5 min after desufflation for blood gases. The significant findings (P < 0.05) were as follows: insufflation produced an increase in heart rate (5 to 15 min and at 30 min), mean arterial blood pressure (25 to 30 min), and diastolic arterial blood pressure (10 to 30 min). After desufflation, respiratory rate increased for 15 min. The changes were within physiologically acceptable limits in these healthy, anesthetized cats despite no artificial maintenance of minute ventilation.  相似文献   

12.
Hemodynamic effects of spontaneous ventilation, intermittent positive-pressure ventilation (IPPV), and high-frequency oscillatory ventilation (HFOV) were compared in 6 dogs during halothane anesthesia. Anesthesia was induced with IV thiamylal Na and was maintained with halothane (end-tidal concentration, 1.09%). During placement of catheters, dogs breathed spontaneously through a conventional semiclosed anesthesia circuit. Data were collected, and dogs were mechanically ventilated, using IPPV or HFOV in random order. Ventilation was adjusted to maintain PaCO2 between 38 and 43 mm of Hg during IPPV and HFOV. Cardiac index, aortic blood pressure, and maximum rate of increase of left ventricular pressure were significantly (P less than 0.05) less during HFOV than during spontaneous ventilation, whereas right atrial and pulmonary artery pressure were significantly greater during HFOV than during spontaneous ventilation. During IPPV, only the maximum rate of increase of left ventricular pressure was significantly less than that during spontaneous ventilation.  相似文献   

13.
The rate of rise of arterial partial pressure of carbon dioxide (PaCO2) was determined in 49 apneic halothane-anesthetized horses following controlled ventilation. Drugs given for induction of anesthesia did not affect the rapid rate of rise of PaCO2 during the first minute after controlled ventilation, the PaCO2 at 1 minute after controlled ventilation, or the PaCO2 at which spontaneous ventilation began. Horses given xylazine-ketamine for induction of anesthesia had a significantly (P less than 0.05) faster rate of rise of PaCO2 after 1 minute following controlled ventilation than did horses receiving xylazine-thiamylal for induction.  相似文献   

14.
OBJECTIVE: To determine whether a laryngeal mask airway (LMA) provides a better airway than a facemask in spontaneously breathing anesthetized rabbits, and to test if it can be used for mechanically controlled ventilation. STUDY DESIGN: Randomized prospective experimental trial. ANIMALS: Sixteen young, healthy, specific pathogen-free Giant Flemish cross Chinchilla rabbits (10 females and 6 males) weighing 4.1 +/- 0.8 kg. METHODS: Rabbits were assigned randomly to one of three treatment groups: facemask with spontaneous ventilation (FM-SV; n = 5), LMA with spontaneous ventilation (LMA-SV; n = 5), and LMA with controlled ventilation (LMA-CV; n = 6). In dorsal recumbency, and at 2.3% end-tidal isoflurane concentration, Fé isoflurane, Fi isoflurane, partial pressure of expired isoflurane (PECO(2)), partial pressure of inspired carbon dioxide (PiCO(2)), heart rate, respiratory rate, minute volume, arterial oxygen tensions (PaO(2)), arterial carbon dioxide tensions (PaCO(2)), arterial pH (pH(a)), arterial standard base excess (SBE(a)) values were measured for 120 minutes. Results Two individuals in the FM-SV group had PaCO(2) > 100 mm Hg. One rabbit in the FM-SV had PaO(2) < 80 mm Hg. All FM-SV rabbits showed signs of airway obstruction, and two were withdrawn from the study at 45 and 90 minutes, respectively, because cyanosis was observed. No signs of airway obstruction were observed in either LMA group. Four rabbits in the LMA-CV group developed gastric tympanism, one of which refluxed gastric contents after 110 minutes. There were no differences between FM-SV and LMA-SV in any variable tested. PaCO(2) and PECO(2) were decreased, while PaO(2) and minute volume were increased in the LMA-CV group compared to the LMA-SV group. CONCLUSIONS: An LMA provided a better airway than a facemask during spontaneous breathing in rabbits, as the use of a facemask was associated with hypercapnia and low partial pressures of oxygen. Although an LMA can be used for intermittent positive pressure ventilation (IPPV), gastric tympanism may develop, especially at a peak inspiratory pressure of 14 cm H(2)O. CLINICAL RELEVANCE: The LMA can be used in rabbits but further work is needed before it is applied routinely.  相似文献   

15.
OBJECTIVE: To determine hemodynamic effects of 3 concentrations of sevoflurane in cats. ANIMALS: 6 cats. PROCEDURE: Cats were anesthetized with sevoflurane in oxygen. After instruments were inserted, end-tidal sevoflurane concentration was set at 1.25, 1.5, or 1.75 times the individual minimum alveolar concentration (MAC), which was determined in another study. Twenty-five minutes were allowed after each change of concentration. Heart rate; systemic and pulmonary arterial pressures; central venous pressure; pulmonary artery occlusion pressure; cardiac output; body temperature; arterial and mixed-venous pH, PCO2, PO2, oxygen saturation, and hemoglobin concentrations; PCV; and total protein and lactate concentrations were measured for each sevoflurane concentration before and during noxious stimulation. Arterial and mixed-venous bicarbonate concentrations, cardiac index, stroke index, rate-pressure product, systemic and pulmonary vascular resistance indices, left and right ventricular stroke work indices, PaO2, mixed-venous partial pressure of oxygen (PVO2), oxygen delivery, oxygen consumption, oxygen-extraction ratio, alveolar-to-arterial oxygen difference, and venous admixture were calculated. Spontaneous and mechanical ventilations were studied during separate experiments. RESULTS: Mode of ventilation did not significantly influence any of the variables examined. Therefore, data from both ventilation modes were pooled for analysis. Mean arterial pressure, cardiac index, stroke index, rate-pressure product, left ventricular stroke work index, arterial and mixed-venous pH, PaO2, and oxygen delivery decreased, whereas PaCO2, PVO2, and mixed-venous partial pressure of CO2 increased significantly with increasing doses of sevoflurane. Noxious stimulation caused a significant increase in most cardiovascular variables. CONCLUSIONS AND CLINICAL RELEVANCE: Sevoflurane induces dose-dependent cardiovascular depression in cats that is mainly attributable to myocardial depression.  相似文献   

16.
The objective of this study was to determine intraocular pressure (IOP) and cardiac changes in normocapnic dogs maintained under controlled ventilation and anesthetized using sevoflurane or desflurane. Sixteen healthy adult mixed-breed dogs, seven males and nine females, weighing 10-15 kg were used. The dogs were randomly assigned to one of two groups composed of eight animals anesthetized with sevoflurane (SEVO) or desflurane (DESF). In both groups, anesthesia was induced with propofol (10 mg/kg), and neuromuscular blockade was achieved with rocuronium (0.6 mg/kg/h i.v.). No premedication was given. Ventilation was adjusted to maintain end-tidal carbon dioxide partial pressure at 35 mmHg. Anesthesia was maintained with 1.5 minimum alveolar concentration (MAC) of sevoflurane or desflurane. In both groups IOP was measured by applanation tonometry (Tono-Pen) before induction of anesthesia. IOP, mean arterial pressure (MAP), heart rate (HR), cardiac index (CI) and central venous pressure (CVP) were also measured 45 min after the beginning of inhalant anesthesia and then every 20 min for 60 min. A one-way repeated measures anova was used to compare data within the same group and Student's t-test was used to assess differences between groups. P < 0.05 was considered statistically significant. Measurements showed normal IOP values in both groups, even though IOP increased significantly from baseline during the use of desflurane. IOP did not differ between groups. CI in the desflurane group was significantly greater than in the sevoflurane group. Sevoflurane and desflurane have no clinically significant effects on IOP, MAP, HR, CI or VCP in the dog.  相似文献   

17.
The minimal anesthetic concentration (MAC) for halothane and cardiopulmonary dose-responses at several concentrations of halothane were determined during spontaneous ventilation in nine young adult Pekin ducks. The MAC for halothane was 1.04 +/- 0.11 (mean +/- SD). There were dose-dependent decreases in ventilation, significant reductions in inspiratory and expiratory times, and prolongation of expiratory pause times. The end-tidal halothane concentration at apnea in five ducks was less than 1.53% and anesthetic index was less than 1.51. Heart rate increased significantly as the concentration of halothane was increased, but arterial blood pressure did not change. Cardiac arrhythmias developed in five ducks at end-tidal halothane concentrations as low as 1.15%, and one duck died of cardiac arrest.  相似文献   

18.
OBJECTIVE: To evaluate the cardiorespiratory effects of controlled versus spontaneous ventilation in pigeons anesthetized for coelioscopy. DESIGN: Prospective study. ANIMALS: 30 healthy adult pigeons (Columbia livia). PROCEDURE: During isoflurane anesthesia, 15 pigeons were allowed to breathe spontaneously (SP group) and 15 were mechanically ventilated (MV group) by use of a pressure-limited ventilator. In each group, cardiopulmonary variables (including end-tidal CO2 concentration [ETCO2]) were measured before (baseline), during, and after coelioscopy. An arterial blood sample was collected for blood gas analyses from each pigeon before coelioscopy and after the procedure, when the caudal thoracic air sac was still open. RESULTS: At baseline, hypoventilation was greater in the SP group than the MV group. Compared with the SP group values, ETCO2 overestimated PaCO2 to a greater degree in the MV group. Cardiovascular variables were not different between groups. After coelioscopy (when the air sac was open), PaCO2 had decreased significantly from baseline in the MV group. In the SP group, hypoventilation worsened despite an increase in respiratory rate. After coelioscopy, PaO2 in the SP group had decreased from baseline and was lower than PaO2 in the MV group; arterial blood pressure and heart rate in the MV group had decreased from baseline and were lower than values in the SP group. CONCLUSIONS AND CLINICAL RELEVANCE: In adult pigeons, controlled ventilation delivered by a pressure-limited device was not associated with clinically important adverse cardiopulmonary changes but may be associated with respiratory alkalosis and cardiovascular depression when air sac integrity has been disrupted.  相似文献   

19.
The cardiopulmonary effects of sevoflurane (mean, 2·6, 3·8–3·9 and 5·2 per cent) were compared with those of halothane (1·2, 1·8 and 2·4 per cent), enflurane (2·4, 3·6 and 4·8 per cent) and isoflurane (1·6, 2·4 and 3·2–3·3 per cent) at end-tidal concentrations equivalent to 1, 1·5 and 2 minimal alveolar concentrations (macs) during spontaneous or controlled ventilation (sv or cv) in 57 cats. Cats were assigned to four groups of nine animals each in sv trial and four groups of five or six animals each in cv trial. During sv, respiration rate was decreased by sevoflurane and isoflurane at 2 mac and by enflurane at each mac multiple when compared with control values, whereas halothane increased respiration rate at 2 mac. The degree of hypercapnia and acidosis induced by sevoflurane was not different from that induced by isoflurane and was less than that induced by halothane at 1 to 1·5 mac or enflurane at 2 mac. During sv and cv, four anaesthetics decreased heart rate at 2 mac when compared with control values, but there was no significant difference between anaesthetics. Sevoflurane, like halothane and isoflurane, induced hypotension at 2 mac when compared with 1 mac.  相似文献   

20.
This study aimed to determine the minimum anesthetic concentration (MAC) and dose-related cardiovascular effects of isoflurane during controlled ventilation in cinereous vultures (Aegypius monachus). The MAC was determined for 10 cinereous vultures as the midpoint between the end-tidal isoflurane concentration that allows gross purposeful movement and that which prevents the movement in response to clamping a pedal digit. Immediately after the MAC was determined, the cardiovascular effects of isoflurane at 1.0, 1.5, and 2.0 times the MAC were investigated in seven of the 10 birds. The MAC of isoflurane for 10 cinereous vultures during controlled ventilation was 1.06 +/- 0.07% (mean +/- SD). When the isoflurane concentration was increased to 1.5 and 2.0 times the MAC, there was significant dose-dependent decrease in the arterial blood pressure. However, the heart rate did not change over a range of 1.0 to 2.0 times the MAC.  相似文献   

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