EVALUATION OF ACUPUNCTURE POINTS GOVERNING VESSELS 1 AND 26 ON ANESTHETIC RECOVERY OF EASTERN BOX TURTLES ( TERRAPENE CAROLINA CAROLINA).

Intramuscular administration of anesthetic agents in chelonians may result in a prolonged (≥1 hr) return of spontaneous movement and breathing, which increases the probability for peri- and postoperative complications. The acupuncture point governing vessel (GV)-26 has been demonstrated to reduce anesthetic recovery times from inhalant anesthesia in other species. In this study, 30 eastern box turtles (EBT; Terrapene carolina carolina), presented to the Turtle Rescue Team at North Carolina State University's College of Veterinary Medicine for treatment of aural abscess, were divided into four groups: control (no treatment); GV-26 acupuncture; GV-1 and GV-26 acupuncture; or GV-1 and GV-26 electroacupuncture. Turtles receiving either GV-1 and GV-26 acupuncture or GV-1 and GV-26 electroacupuncture had a significantly reduced time to return of voluntary movement ( P = 0.012 and P = 0.006, respectively), a significantly reduced time to response of limb extension ( P = 0.03 and P < 0.001, respectively), and a significantly reduced time to anesthetic recovery ( P < 0.05 and P < 0.01, respectively). Therefore, the use of either GV-1 and GV-26 acupuncture or GV-1 and GV-26 electroacupuncture produces significant reductions in anesthetic recovery time in EBTs that have received injectable anesthetics.

EPINEPHRINE OR GV-26 ELECTRICAL STIMULATION REDUCES INHALANT ANESTHESTIC RECOVERY TIME IN COMMON SNAPPING TURTLES (CHELYDRA SERPENTINA).

Prolonged anesthetic recovery times are a common clinical problem in reptiles following inhalant anesthesia. Diving reptiles have numerous adaptations that allow them to submerge and remain apneic for extended periods. An ability to shunt blood away from pulmonary circulation, possibly due to changes in adrenergic tone, may contribute to their unpredictable inhalant anesthetic recovery times. Therefore, the use of epinephrine could antagonize this response and reduce recovery time. GV-26, an acupuncture point with reported ß-adrenergic and respiratory effects, has reduced anesthetic recovery times in other species. In this prospective randomized crossover study, six common snapping turtles (Chelydra serpentina) were anesthetized with inhalant isoflurane for 90 min. Turtles were assigned one of three treatments, given immediately following discontinuation of isoflurane: a control treatment (0.9% saline, at 0.1 ml/kg i.m.), epinephrine (0.1 mg/kg i.m.), or acupuncture with electrical stimulation at GV-26. Each turtle received all treatments, and treatments were separated by 48 hr. Return of spontaneous ventilation was 55% faster in turtles given epinephrine and 58% faster in the GV-26 group versus saline (P < 0.001). The times to movement and to complete recovery were also significantly faster for both treatments than for saline (P < 0.02). Treated turtles displayed increases in temperature not documented in the control (P < 0.001). Turtles administered epinephrine showed significantly increased heart rates and end-tidal CO(2) (P < 0.001). No adverse effects were noted in the study animals. The mechanisms of action were not elucidated in the present investigation. Nevertheless, the use of parenteral epinephrine or GV-26 stimulation in the immediate postanesthetic period produces clinically relevant reductions in anesthetic recovery time in common snapping turtle. Further research is necessary to evaluate the effects of concurrent GV-26 and epinephrine administration and to assess responses in other reptilian species.

Effects of magnesium sulfate and propofol on the minimum alveolar concentration preventing motor movement in sevoflurane-anesthetized dogs.

OBJECTIVE To evaluate the effect of MgSO4, alone and in combination with propofol, on the minimum alveolar concentration preventing motor movement (MACNM) in sevoflurane-anesthetized dogs. ANIMALS 6 healthy purpose-bred adult male Beagles (least squares mean ± SEM body weight, 12.0 ± 1.1 kg). PROCEDURES Dogs were anesthetized 3 times at weekly intervals. The MACNM was measured 45 minutes after induction of anesthesia (baseline; MACNM-B) and was determined each time by use of a noxious electrical stimulus. Treatments were administered as a loading dose and constant rate infusion (CRI) as follows: treatment 1, MgSO4 loading dose of 45 mg/kg and CRI of 15 mg/kg/h; treatment 2, propofol loading dose of 4 mg/kg and CRI of 9 mg/kg/h; and treatment 3, MgSO4 and propofol combination (same doses used previously for each drug). A mixed-model ANOVA and Tukey-Kramer tests were used to determine effects of each treatment on the percentage decrease from MACNM-B. Data were reported as least squares mean ± SEM values. RESULTS Decrease from MACNM-B was 3.4 ± 3.1%, 48.3 ± 3.1%, and 50.3 ± 3.1%, for treatments 1, 2, and 3, respectively. The decrease for treatments 2 and 3 was significantly different from that for treatment 1; however, no significant difference existed between results for treatments 2 and 3. CONCLUSIONS AND CLINICAL RELEVANCE MgSO4 did not affect MACNM, nor did it potentiate the effects of propofol on MACNM. Administration of MgSO4 in this study appeared to provide no clinical advantage as an anesthetic adjuvant.

Performance of a new carbon dioxide absorbent, Yabashi lime® as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs.

In the present study, we compare a new carbon dioxide (CO2) absorbent, Yabashi lime(®) with a conventional CO2 absorbent, Sodasorb(®) as a control CO2 absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime(®) with high or low-flow rate of oxygen and control CO2 absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carbooxyhemoglobin (COHb) concentration in the blood were measured. Yabashi lime(®) did not produce CA. Control CO2 absorbent generated CA, and its concentration was significantly higher in low-flow rate than a high-flow rate. CO was generated only in low-flow rate groups, but there was no significance between Yabashi lime(®) groups and control CO2 absorbent groups. However, the CO concentration in the circuit could not be detected (≤5ppm), and no change was found in COHb level. Canister temperature was significantly higher in low-flow rate groups than high-flow rate groups. Furthermore, in low-flow rate groups, the lower layer of canister temperature in control CO2 absorbent group was significantly higher than Yabashi lime(®) group. CA and CO productions are thought to be related to the composition of CO2 absorbent, flow rate and canister temperature. Though CO concentration is equal, it might be safer to use Yabashi lime(®) with sevoflurane anesthesia in dogs than conventional CO2 absorbent at the point of CA production.

Anestesia convencional e técnica de tumescência em cadelas submetidas à mastectomia. Avaliação da dor pós-operatória / Conventional anesthesia and tumescent technique in bitches which underwent mastectomy. Evaluation of postoperative pain

As neoplasias mamárias são as mais comuns em cadelas e geralmente acometem fêmeas de meia-idade a idosas, não castradas ou que foram submetidas ao procedimento de ovario-histerectomia tardiamente. A principal forma de tratamento é a excisão cirúrgica, sendo a ressecção unilateral das glândulas mamárias o procedimento mais realizado na prática veterinária. O objetivo do presente estudo foi comparar a dor pós-operatória em cadelas submetidas ao procedimento de mastectomia unilateral sob efeito das técnicas anestésicas de tumescência ou convencional. Foram utilizadas 20 cadelas, divididas em dois grupos: um grupo recebeu apenas a anestesia geral inalatória (grupo convencional), e o outro recebeu adicionalmente a anestesia infiltrativa por tumescência (grupo tumescência). Elas foram avaliadas nas primeiras 24 horas do período pós-operatório, e o processo álgico foi avaliado pela escala de dor da Universidade de Melbourne. As médias dos escores obtidos ao longo do tempo foram submetidas ao teste de Tukey a um nível de 5 por cento de significância (p<0,05). Não foram observadas diferenças significativas entre os grupos com relação à dor pós-operatória. A técnica anestésica infiltrativa por tumescência apresentou a vantagem da redução do sangramento transoperatório e mostrou-se exequível em pequenos animais, entretanto seu uso está relacionado à experiência e à preferência do cirurgião e do anestesista...

Mammary tumors are the most common neoplasm in bitches. Intact, mild to advanced aged female dogs are generally more affected. The main treatment is surgical excision and unilateral mastectomy is the most performed procedure in veterinary practice. The aim of this study was to compare the postoperative pain in dogs which underwent unilateral mastectomy and were anesthetized with tumescence and conventional anesthesia. Twenty bitches were randomly divided into two groups: Conventional Group (GC), which received only general inhalational anesthesia and Tumescence Group (GT), which also received tumescence anesthesia. All dogs were evaluated during the first 24 hours postoperatively. The scale of Pain from the University of Melbourne was used for the evaluation. The tukey test at a 5 percent level of significance (p <0.05) was used. There were no significant differences between groups related to postoperative pain. The technique of tumescent anesthesia reduced bleeding during surgery and is feasible in dogs. Its use is related to the surgeon and anesthesiologist's experience and preferences...

Evaluation of inflammatory and hemostatic surgical stress responses in male cats after castration under general anesthesia with or without local anesthesia.

OBJECTIVE: To characterize acute inflammatory and hemostatic surgical stress responses following castration in cats and to evaluate whether the addition of local anesthesia to the anesthetic protocol attenuates these responses. ANIMALS: 39 male cats. PROCEDURES: Cats undergoing castration were randomly assigned to 2 groups: both groups underwent surgery with general anesthesia, and 1 group additionally received a local anesthetic (lidocaine [2.0 mg/kg in total, divided intratesticularly and SC]) prior to incision. Blood samples were collected after anesthetic induction (baseline) and 1, 5, and 24 hours later. Thromboelastography and coagulation variables (activated partial thromboplastin time [aPTT] and prothrombin time [PT]) were analyzed; fibrinolysis was assessed with plasma D-dimer concentrations. The acute-phase response was evaluated via measurement of plasma fibrinogen and serum amyloid A (last time point, 28 hours) concentrations. Hematologic variables were analyzed at baseline and 1, 5, and 24 hours later. RESULTS: Evidence of hemostatic and inflammatory activation after surgery was detected in both groups. Maximum amplitude and G (global clot strength) were significantly increased at 24 hours, and significant, but not clinically relevant, decreases were detected in aPTT at 5 and 24 hours and in PT at 24 hours, compared with baseline values. Serum amyloid A concentrations were significantly higher at 24 and 28 hours than at baseline, and plasma fibrinogen concentration was significantly increased at 24 hours; WBC and RBC counts and Hct were significantly increased at multiple time points. No differences between groups were detected for any variables. CONCLUSIONS AND CLINICAL RELEVANCE: Castration appeared to induce hypercoagulability and an acute-phase inflammatory response in cats. Local anesthesia with lidocaine did not attenuate this response.

Comparative evaluation of halothane anaesthesia in medetomidine-butorphanol and midazolam-butorphanol premedicated water buffaloes (Bubalus bubalis).

Six clinically healthy male water buffaloes (Bubalus bubalis) 2-3 years of age and weighing 290-325 kg were used for 2 different treatments (H1 and H2). The animals of group H1 were premedicated with medetomidine (2.5 g/kg,i.v.) and butorphanol (0.05 mg/kg, i.v.), while in group H2 midazolam (0.25 mg/kg) and butorphanol (0.05 mg/kg) were used intravenously. Induction of anaesthesia was achieved by 5% thiopental sodium in H1 (3.85 +/- 0.63 mg/kg) and H2 (6.96 +/- 0.45 mg/kg) groups. The anaesthesia was maintained with halothane in 100 % oxygen through a large animal anaesthetic machine. Better analgesia and sedation with a significantly lower dose of thiopental for induction and significantly higher values of sternal recumbency time and standing time were recorded in group H1 than in group H2, whereas no significant (P > 0.05) difference for the halothane concentration was observed between groups H1 and H2. Significant decrease in heart rate was observed in group H1 whereas it significantly increased in group H2. In both groups, RR decreased during the preanaesthetic period, which increased significantly (P < 0.01) after halothane administration. In both groups a significant (P < 0.01) fallin RT was recorded from 20 min to the end of observation period. A significant (P < 0.05) fall in MAP was observed in group H1 from 15 min until the end, while in group H2 MAP increased nonsignificantly (P > 0.05) after premedication and a significant (P < 0.05) occurredafter thiopental administration. In both groups a significant (P < 0.01) increase in CVP and a significant (P < 0.01) decrease in SpO2 were observed after premedication which persisted up to 120 min. ECG changes included significant (P < 0.01) decrease and increase in QRS amplitudes in groups H1 and H2 respectively, a significant (P < 0.05) increase in PR interval was recorded at 15 min in group H1, a significant (P < 0.05) decrease in PR interval in group H2, a significant (P < 0.05) decrease in T wave amplitude in group H1, and a significant (P < 0.01) increase in duration of T wave in group H1 . It is concluded that both combinations can be used safely in buffaloes for surgery of 2 h duration but better sedation, analgesia and muscular relaxation and more dose sparing effect on anaesthetics and shorter recovery times were observed in group H1.

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.

Effect of electroacupuncture on minimum alveolar concentration of isoflurane in dogs.

The effect of electroacupuncture (EA) on minimum alveolar concentration (MAC) of isoflurane was evaluated in dogs. After determination of baseline MAC, EA was applied at each acupoints (LI-4, SP-6, ST-36 and TH-8) and nonacupoint for 30 min. MAC was determined again. EA at acupoints significantly lowered the MAC of isoflurane in dogs (17.5 +/- 3.1%, 21.3 +/- 8.0%, 21.2 +/- 7.5% and 15.4 +/- 3.1%, respectively). In control group and nonacupoint electrical stimulation group MAC were not decreased significantly. From these results, electroacupuncture at each acupoints used in the present study would have an advantage in isoflurane anesthesia with reducing its requirement.

[Anesthesia and analgesia of ornamental birds]. / Anästhesie und Analgesie bei Ziervögeln.

Pet birds are frequently viewed as difficult patients for anaesthesia. The present paper revises the current anaesthetic procedures for injectable and inhalant anaesthetics. Currently the method of choice for the anaesthesia of pet birds is the isoflurane inhalation anaesthesia. Special emphasis is given to the preanaesthetic preparations. Fasting is shorter for pet birds than for mammals. Anaesthetized birds are at special risk for hypothermia. Methods for the prevention of heat loss are given. The use of analgesics are recommended both for welfare reasons but also because of the possibility to reduce the concentration of inhalation anaesthetics and therefore the amount of possible exposure of personnel to waste gases.

Effects of electroacupuncture on minimum alveolar concentration of isoflurane and cardiovascular system in isoflurane anesthetized dogs.

The effects of electroacupuncture (EA) on the minimum alveolar concentration (MAC) and on the cardiovascular system were evaluated with dogs under isoflurane anesthesia. Eight healthy male beagles were randomly assigned to six study groups (five heads/group) with washout intervals of 7 ~ 31 days between experiments for recovery and anesthetic clearance. MAC of isoflurane and cardiovascular parameters were determined after EA at nonacupoint and and at acupoints LI-4, SP-6, ST-36 and TH-8. Electroacupuncture for 30 minutes at LI-4, SP-6, ST-36 and TH-8 acupoints lowered the MAC of isoflurane by 17.5 +/- 3.1%, 21.3 +/- 8.0%, 20.5 +/- 8.2% and 15.6 3.1%, respectively (p < 0.05). However, electrical stimulation of nonacupoint did not induce a significant change in MAC of isoflurane. In the cardiovascular system, the ST-36 group did not induce any significant change in cardiovascular parameters. In the TH-8 group, the mean and diastolic arterial pressure and the systemic vascular resistance were decreased. In the LI-4 group, cardiac output and cardiac index decreased after EA. These results indicate that EA at LI-4, SP-6 and ST-36 have advantages in isoflurane anesthesia in terms of reducing the dose of anesthetics and minimizing cardiovascular side effects.

Respiratory depressant and skeletal muscle relaxant effects of low-dose pancuronium bromide in spontaneously breathing, isoflurane-anesthetized dogs.

OBJECTIVE: To assess and compare the respiratory depressant and skeletal muscle relaxant effects of two low doses of a nondepolarizing neuromuscular blocker, pancuronium bromide. To determine if a "low dose" of pancuronium bromide can produce selective skeletal muscle relaxation in extraocular muscles sufficient to perform intraocular surgery while sparing or minimizing depression of muscles of ventilation. STUDY DESIGN: Blinded, randomized crossover, placebo controlled study. ANIMALS: Six healthy, adult mongrel dogs weighing 20.8 +/- 1.9 kg. METHODS: Spontaneously breathing, isoflurane-anesthetized dogs received 0.02 mg/kg pancuronium bromide, intravenously (i.v.), (high dose [HD]), 0.01 mg/kg pancuronium bromide, i.v., (low dose [LD]), or saline placebo i.v. in a blinded, randomized crossover study. Indices of patient ventilation including tidal volume (Vt), respiratory rate (RR), and minute ventilation (VE) were recorded throughout the study period. Serial arterial blood gas analyses were performed at timed intervals. Neuromuscular blockade of skeletal muscle was assessed at timed intervals with train-of-four stimulus/response ratios. Eye position scores, based on the degree of ocular rotation from a neutral gaze axis, were assigned by an ophthalmologist who was blinded to the treatment given. RESULTS: VT and VE in HD dogs decreased by 82% from baseline after administration of pancuronium bromide. Similarly, Vt and VE in LD dogs decreased 40% and 55%, respectively. Decreased ventilation in HD dogs corresponded with significant (P< .05) neuromuscular blockade, as indicated by train-of-four ratio less than 75% between 0 and 60 minutes. Eye position scores in HD and LD dogs were suitable for intraocular surgery between 0 and 60 minutes. Eye position scores in five of six control dogs were unsuitable for intraocular surgery at any time period. CONCLUSIONS: LD dogs experienced only transient, mild to moderate respiratory depression compared with HD dogs, which experienced prolonged, moderate to severe respiratory depression. Both LD and HD dogs acquired and maintained eye position scores suitable for intraocular surgery between 0 to 60 minutes. A "low dose" of pancuronium bromide, which would provide adequate extraocular muscle relaxation while minimizing ventilatory depression, was not identified. CLINICAL RELEVANCE: All patients receiving any dose of neuromuscular blocking agents should be closely monitored and receive ventilatory assistance as needed.

Effects of high-dose gentamicin sulfate on neuromuscular blockade in halothane-anesthetized horses.

OBJECTIVE: To evaluate effects of a single high dose of gentamicin on neuromuscular function in horses anesthetized with halothane. ANIMALS: 6 healthy adult horses. PROCEDURE: Halothane-anesthetized horses were positioned in left lateral recumbency, and the right hind limb was immobilized in a reusable fiberglass cast fixed to a steel frame. The hoof was attached to a force transducer, and resting tension of 0.93 +/- 0.16 kg was maintained. A supramaximal train-of-four stimulus of 2 Hz for a duration of 0.25 millisecond was applied to the superficial peroneal nerve every 20 seconds by a square-wave stimulator. The force of the evoked digital extensor tension was recorded to determine first muscle twitch tension, compared with the baseline value (T1%) and the ratio of the force of the fourth twitch to the first twitch (T4/T1). Data were recorded at 5, 10, 15, 30, and 60 minutes after i.v. administration of vehicle or gentamicin (6 mg/kg of body weight). RESULTS: There was a significant (P = 0.04) treatment-time interaction for the effect of gentamicin on T1%; T1% associated with vehicle decreased from 100% to 92% during the 60- minute study period, but no decrease was associated with gentamicin. For T4/T1, there was no significant effect of treatment or time or treatment-time interaction between gentamicin and vehicle. CONCLUSIONS: Gentamicin did not cause a decrease in initial muscular strength, nor did it impair the muscles' ability to sustain strength. CLINICAL RELEVANCE: A single high dose of gentamicin does not cause significant neuromuscular blockade when administered alone to healthy horses anesthetized with halothane.

Comparison of the postoperative analgesic and sedative effects of carprofen and papaveretum in the dog.

Forty dogs undergoing a variety of surgical procedures were assigned randomly to one of two groups. All the animals were premedicated with acepromazine (0.05 mg/kg bodyweight) intramuscularly, and anaesthesia was induced with thiopentone sodium, or propofol in the case of lean animals, and maintained with halothane in an oxygen/nitrous oxide mixture using a non-rebreathing circuit. The dogs in group 1 were given papaveretum (0.2 mg/kg) slowly intravenously within 35 minutes of induction of anaesthesia and the dogs in group 2 were given carprofen (4 mg/kg) in the same way. The dogs were scored for sedation and pain by a trained theatre nurse, who did not know which group they belonged to, using a visual analogue scale, at 15, 30, 60, 120, 240 and 360 minutes after the halothane was switched off at the end of the procedure. Nine of the dogs were withdrawn from the trial (eight of them from the papaveretum group) because of inadequate pain relief and these animals were given pethidine (3 mg/kg intramuscularly) which produced adequate analgesia within 15 minutes in all but one case. Carprofen provided profound analgesia which was as effective and of longer duration than that produced by papaveretum, and was associated with significantly less postoperative sedation and a quicker return to the normal conscious state.

Laryngotomy as a treatment for chronic laryngeal obstruction in cattle: a review of 130 cases.

One hundred and thirty cattle with chronic laryngeal obstruction were treated by surgery; the diagnostic and operative techniques are discussed. A simplified technique using local anaesthesia of the laryngeal area was used in sedated calves weighing up to 200 kg. Inhalation anaesthesia through a distal tracheotomy was needed in heavier animals. Complications related to the surgical intervention are described. The animals were reviewed from five months to over one year after discharge from the clinic. The long term survival rate of the 130 animals was 58 per cent. The results after surgery were excellent in 40.9 per cent and good in 15.2 per cent of the animals.

Anesthesia techniques in sheep and goats.

A variety of techniques can be used to anesthetize and restrain sheep and goats safely and humanely both in the clinic and in the field. The use of inhalational, injectable, and local anesthetic agents is discussed. Nontraditional agents (opioids and alpha-2 adrenergic agonists) for epidural analgesia also are reviewed because of their promising clinical application.

[Collection of sperm from foxes using electroejaculation under halothane anesthesia]. / Získavanie spermy od lisiakov metódou elektroejakulácie v halotanovej narkóze.

A method has been developed for the collection of ejaculate from anaesthesized dog foxes. General anaesthesia was produced by inhaling 3 to 5% narcotan mixed with oxygen, the inhalation rate being two litres per minute. An electroejaculator with a bipolar electrode, introduced in the rectum, was used for the electrostimulation of ejaculation. The voltage needed to produce the ejaculation effect and the number of impulses depended on the individuality of the foxes. The average amount of ejaculate per one collection was 0.86 ml, the sperm motility percentage was 74.80% sperm concentration was 270.62 x 10(3) spermatozoa per mm3, and the average pH value was 6.87.

Isoflurane as an anesthetic for experimental animal surgery.

Isoflurane is an inhalational anesthetic agent associated with no known hepatic toxicity. Despite this fact, isoflurane has not been widely utilized as an anesthetic agent in studies of liver structure and function in experimental animals. For this reason, livers from rats treated with pentobarbital or diethylether were compared to those from rats treated with isoflurane to determine differences in biochemical and morphologic parameters. Liver from pentobarbital-treated rats showed a significant decline in glutathione-S-transferase activity compared to liver from isoflurane/O2 or ether-treated rats. Liver microsomes from isoflurane/O2-treated rats retained more cytochrome-C(P450)-reductase activity than did those from pentobarbital-treated, ether-treated, or decapitated rats. Despite these biochemical alterations, morphometric analysis of liver from isoflurane/O2 and pentobarbital-treated rats showed no quantitative or qualitative differences in liver structure or organelle volume densities. Neither were differences detected in uptake and distribution of 125I-epidermal growth factor when analyzed by electron microscopic autoradiography. These data show that isoflurane with supplemental O2 has no effects on hepatic structure and fewer effects on hepatic function than other anesthetics and may be a better experimental anesthetic than any currently in use.

[Anesthesia in birds]. / Anästhesie beim Vogel.

Anaesthesia in birds is ordered by law and is also necessary for various operations and manipulations. Anaesthesia by injection of Ketamin, which in special cases may be combined with Diazepam, has been found useful. Anaesthesia by inhalation with Halothan, Methoxyfluran or Isofluran is the most careful method. Local anaesthesia has few indications.

Potency of isoflurane and nitrous oxide in conventional swine.

The minimum alveolar concentration (MAC) of isoflurane in oxygen (O2) was determined to be 1.55 +/- 0.08 (SEM) volumes % in twelve pigs (Sus scrofa). Values for isoflurane MAC in the presence of 50% (I-50%N2O) and 66% (I-66%N2O) nitrous oxide were determined in nine and six of these same animals, respectively, and equalled 1.03 +/- 0.05 vol % for I-50%N2O and 0.95 +/- 0.07 vol % for I-66%N2O. Animals respired spontaneously and arterial blood pressure (AP), heart rate (HR), rectal body temperature, and arterial blood gases (PO2, PCO2, and pH) were recorded throughout the study period. These parameters were within normal limits near MAC for all three gas combinations. The MAC for isoflurane in swine was similar to that for other animals and, man and the use of this agent was associated with rapid and uneventful anesthetic induction and recovery. The addition of 50% and 66% nitrous oxide (N2O) reduced the isoflurane MAC by 30% and 42%, respectively.