Hepatotoxic and neuroendocrine effects in physicians occupationally exposed to most modern halogenated anesthetics and nitrous oxide.

The lack of data on hepatic and hormonal markers for occupational exposure to most modern halogenated anesthetics has stimulated our research, which assessed liver enzymes, high-sensitivity C-reactive protein (hs-CRP) and neuroendocrine response. The study investigated 106 physicians who were categorized in an exposed group (primarily exposed to isoflurane and sevoflurane and less to desflurane and nitrous oxide) as well as as a control group. Anesthetic air monitoring was performed, and biological samples were analyzed for the most important liver enzymes, hs-CRP, adrenocorticotrophic hormone, cortisol and prolactin. No biomarkers were significantly different between the groups. Exposed males showed significant increases in cortisol and prolactin compared to unexposed males. However, values were within the reference ranges, and 22 % of exposed males versus 5 % of unexposed males exhibited higher prolactin values above the reference range. This study suggests that occupational exposure to the most commonly used inhalational anesthetics is not associated with hepatotoxicity or neurohormonal changes.

Comparison of use of isoflurane or sevoflurane for anaesthesia induced by mask in calves

Background: Inhalation anaesthesia is an effective and reliable general anaesthesia method for inactivity, analgesia, and unconsciousness in extensive surgical procedures. Although widely used, especially in small animals, there are very few studies investigated the reliability and superiority of inhalation anaesthesia in surgical procedures for ruminants. This study intended to evaluate the anaesthetic effects of isoflurane and sevoflurane in different surgical cases with endotracheal intubation following the induction of anaesthesia using a calve-specific facemask, which is not yet a routine option in cattle. Materials, Methods & Results: The study was conducted on 14 calves, from new-born up to 3 months-old, that undergoing various surgical operations. The animals were divided into isoflurane and sevoflurane groups, and each group contained 7 animals. In all cases, atropine (0.04 mg/kg was administered intramusculer as premedication before 15 min from anaesthesia induction. For induction, the anaesthetic agent was given at an inspiratory concentration of 3-5% in the isoflurane group and at an inspiratory concentration of 5 - 7% in the sevoflurane group during 5 min via mask at 15 min after atropine administration. In both groups, endotracheal intubation was performed (about 1-3 min) after of general anaesthesia symptoms starting. At 5 min after induction, anaesthesia was continued at 1.5 - 3% in the isoflurane group and at 2.5 - 4% in the sevoflurane group during operation. The animals were monitored during anaesthesia and, anaesthetic effect, reaction of the calve, pronounced side effects, Heart Rate (HR), Systolic Arterial Blood Pressure (SABP), Diastolic Arterial Blood Pressure (DABP), Mean Arterial Blood Pressure (MABP), Respiration Rate (RR), Pulse Rate (PR), Arterial Oxygen Saturation (SpO2 ) were recorded at before anaesthesia, the premedication period, 5...

Comparison of the effects of isoflurane and sevoflurane general anaesthesia after induction by propofol on clinical and physiological measurements in calves

Background: In veterinary surgical operations for cats and dogs, inhalation anaesthesia is known to be a good option forgeneral anaesthesia in long operations or emergency cases. Studies have revealed that during inhalation anaesthesia, theheart and respiratory functions of the animals are more stable compared to injectable anaesthesia. However, there are fewstudies performed with the use of inhalation anaesthesia in ruminants. In this research, the goal is to evaluate the effectsof isoflurane and sevoflurane after induction with propofol in calves based on clinical and physiological parameters andto find a more reliable strategy for general anaesthesia in ruminants.Materials, Methods & Results: The research was carried out on 30 calves, from new-born up to 3-month-old, undergoingsurgery operation. Each group consisted of 15 animals that were divided as isoflurane and sevoflurane. For premedication,atropine was administered at a dose of 0.04 mg/kg via subcutaneous injection in calves. For induction, 15 min after atropineapplication, propofol was given at 5-6 mg/kg via intravenous infusion. Then, endotracheal intubation was performed andinhalation anaesthesia began at 5 min after induction. In the isoflurane group, the onset of anaesthesia concentration wasset to 3-5% and the maintenance was set to a concentration of 1.5-3%. In the sevoflurane group, the onset of anaesthesiaconcentration was set to 5-7% and the maintenance was set to a concentration of 2.5-4%. To monitor the calves, the heartrate (HR), the pulse rate (PR), the systolic blood pressure (SBP), the diastolic blood pressure (DBP), the respiratory rate(RR), the rectal temperature (RT) and the electrocardiogram (ECG) measurements were recorded before anaesthesia, thepremedication, the induction periods, at 5, 15, 30, 45, 60, and 75 min after the onset of inhalation anaesthesia during theoperation period. Blood samples were taken before anaesthesia, premedication, induction periods...(AU)

Comparison of the effects of isoflurane and sevoflurane general anaesthesia after induction by propofol on clinical and physiological measurements in calves

Background: In veterinary surgical operations for cats and dogs, inhalation anaesthesia is known to be a good option forgeneral anaesthesia in long operations or emergency cases. Studies have revealed that during inhalation anaesthesia, theheart and respiratory functions of the animals are more stable compared to injectable anaesthesia. However, there are fewstudies performed with the use of inhalation anaesthesia in ruminants. In this research, the goal is to evaluate the effectsof isoflurane and sevoflurane after induction with propofol in calves based on clinical and physiological parameters andto find a more reliable strategy for general anaesthesia in ruminants.Materials, Methods & Results: The research was carried out on 30 calves, from new-born up to 3-month-old, undergoingsurgery operation. Each group consisted of 15 animals that were divided as isoflurane and sevoflurane. For premedication,atropine was administered at a dose of 0.04 mg/kg via subcutaneous injection in calves. For induction, 15 min after atropineapplication, propofol was given at 5-6 mg/kg via intravenous infusion. Then, endotracheal intubation was performed andinhalation anaesthesia began at 5 min after induction. In the isoflurane group, the onset of anaesthesia concentration wasset to 3-5% and the maintenance was set to a concentration of 1.5-3%. In the sevoflurane group, the onset of anaesthesiaconcentration was set to 5-7% and the maintenance was set to a concentration of 2.5-4%. To monitor the calves, the heartrate (HR), the pulse rate (PR), the systolic blood pressure (SBP), the diastolic blood pressure (DBP), the respiratory rate(RR), the rectal temperature (RT) and the electrocardiogram (ECG) measurements were recorded before anaesthesia, thepremedication, the induction periods, at 5, 15, 30, 45, 60, and 75 min after the onset of inhalation anaesthesia during theoperation period. Blood samples were taken before anaesthesia, premedication, induction periods...

Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital / Comparação de resíduos de gases anestésicos em salas de operação com ou sem sistema de exaustão em hospital universitário brasileiro

Abstract Background and objectives Occupational exposure to waste anesthetic gases in operating room without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhalational anesthetics isoflurane and sevoflurane in operating room with and without central scavenging system. Method Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station) and at two times (30 and 120 min after the start of surgery) in both operating room types. Results All isoflurane and sevoflurane concentrations in unscavenged operating room were higher than the US recommended limit (2 parts per million), regardless of the location and time evaluated. In scavenged operating room, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. Conclusions The exposure to both anesthetics exceeded the international limit in unscavenged operating room. In scavenged operating room, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the operating room scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values.

Resumo Justificativa e objetivos A exposição ocupacional aos resíduos de gases anestésicos em salas de operação (SO) sem sistema ativo de exaustão tem sido associada a efeitos adversos à saúde. Assim, o objetivo do estudo foi comparar os resíduos dos anestésicos inalatórios isoflurano e sevoflurano em SO com e sem sistema de exaustão. Método Concentrações residuais de isoflurano e sevoflurano foram mensuradas por analisador infravermelho em diferentes locais (próximo à área respiratória do auxiliar de enfermagem e do anestesiologista e próximo à estação de anestesia) e em dois momentos (30 e 120 min após o início da cirurgia) em ambos os tipos de SO. Resultados Todas as concentrações de isoflurano e sevoflurano nas SO sem sistema de exaustão foram mais elevadas em relação ao valor limite recomendado pelos EUA (2 partes por milhão), independentemente do local e momento avaliados. Nas SO com sistema de exaustão, as concentrações médias de isoflurano ficaram dentro do limite de exposição, exceto para as mensurações próximas à estação de anestesia, independentemente dos momentos avaliados. Para o sevoflurano, as concentrações excederam o valor limite em todos locais de medição e nos dois momentos. Conclusões A exposição a ambos os anestésicos excedeu o limite internacional nas SO sem sistema de exaustão. Nas SO com sistema de exaustão, as concentrações de sevoflurano, e em menor extensão, as de isoflurano excederam o valor limite recomendado. Dessa forma, o sistema de exaustão das SO analisado no presente estudo diminuiu as concentrações dos anestésicos, embora não tenha reduzido a valores internacionalmente recomendados.

[Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital]. / Comparação de resíduos de gases anestésicos em salas de operação com ou sem sistema de exaustão em hospital universitário brasileiro.

BACKGROUND AND OBJECTIVES: Occupational exposure to waste anesthetic gases in operating room (OR) without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhaled anesthetics isoflurane and sevoflurane in OR with and without central scavenging system. METHOD: Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station) and at two times (30 and 120minutes after the start of surgery) in both OR types. RESULTS: All isoflurane and sevoflurane concentrations in unscavenged OR were higher than the US recommended limit (2 parts per million), regardless of the location and time evaluated. In scavenged OR, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. CONCLUSIONS: The exposure to both anesthetics exceeded the international limit in unscavenged OR. In scavenged OR, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the OR scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values.

Minimum alveolar concentration of isoflurane in dogs administered a single intramuscular injection of racemic or S (+)-ketamine after premedication with acepromazine-morphine / Concentração alveolar mínima do isoflurano em cães tratados com dose única intramuscular de cetamina racêmica ou S (+) após premedicação com acepromazina-morfina

The present study evaluated the minimum alveolar concentration of isoflurane (ISOMAC) in twenty three dogs premedicated with acepromazine (0.02mgkg-1) and morphine (0.5mgkg-1) and administered racemic (RK) or S(+)-ketamine (SK). Dogs randomly received a single dose (3mgkg-1, IM) of either RK or SK 15minutes after anesthetic induction with propofol. The ISOMAC was determined by the up-and-down method. Approximately 20 minutes after administration of RK or SK, a surgical noxious stimulus was applied and the response evaluated. The ISOMAC was 0.50±0.01% in the RK group (n=10) and 0.31±0.04% in the SK group (n=13). The ISOMAC was 38% lower in the SK group compared to the RK group. Results of the present study revealed that in dogs premedicated with acepromazine and morphine, IM administration of 3mgkg-1 ketamine approximately 20 minutes before the noxious stimulus produced clinically important reduction in the ISOMAC and the MAC-sparing effect was significantly greater with SK compared to RK.(AU)

No presente estudo, foi avaliada a concentração alveolar mínima do isoflurano (CAMISO) em vinte e três cães premedicados com acepromazina (0,02mgkg-1) e morfina (0,5mgkg-1) e tratados com cetamina racêmica (CR) ou S(+) (CS). Os cães receberam aleatoriamente dose única (3mgkg-1, IM) de CR ou CS, decorridos 15 minutos da indução anestésica com propofol. A CAMISO foi determinada pelo método up-and-down. Aproximadamente 20 minutos após a administração da CR ou CS, um estímulo nociceptivo (cirúrgico) foi aplicado e a resposta avaliada. A CAMISO foi 0,50±0,01% no CR (n=10) e 0,31±0,04% no CS (n=13). A CAMISO foi 38% menor no CS comparado ao CR. Os resultados deste estudo revelaram que, em cães premedicados com acepromazina e morfina, a administração IM de 3mgkg-1 de cetamina, aproximadamente 20 minutos antes do estímulo nociceptivo, causou redução clinicamente importante na CAMISO e o efeito redutor na CAMISO é significativamente maior com CS do que com CR.(AU)

Minimum alveolar concentration of isoflurane in dogs administered a single intramuscular injection of racemic or S (+)-ketamine after premedication with acepromazine-morphine / Concentração alveolar mínima do isoflurano em cães tratados com dose única intramuscular de cetamina racêmica ou S (+) após premedicação com acepromazina-morfina

The present study evaluated the minimum alveolar concentration of isoflurane (ISOMAC) in twenty three dogs premedicated with acepromazine (0.02mgkg-1) and morphine (0.5mgkg-1) and administered racemic (RK) or S(+)-ketamine (SK). Dogs randomly received a single dose (3mgkg-1, IM) of either RK or SK 15minutes after anesthetic induction with propofol. The ISOMAC was determined by the up-and-down method. Approximately 20 minutes after administration of RK or SK, a surgical noxious stimulus was applied and the response evaluated. The ISOMAC was 0.50±0.01% in the RK group (n=10) and 0.31±0.04% in the SK group (n=13). The ISOMAC was 38% lower in the SK group compared to the RK group. Results of the present study revealed that in dogs premedicated with acepromazine and morphine, IM administration of 3mgkg-1 ketamine approximately 20 minutes before the noxious stimulus produced clinically important reduction in the ISOMAC and the MAC-sparing effect was significantly greater with SK compared to RK.

No presente estudo, foi avaliada a concentração alveolar mínima do isoflurano (CAMISO) em vinte e três cães premedicados com acepromazina (0,02mgkg-1) e morfina (0,5mgkg-1) e tratados com cetamina racêmica (CR) ou S(+) (CS). Os cães receberam aleatoriamente dose única (3mgkg-1, IM) de CR ou CS, decorridos 15 minutos da indução anestésica com propofol. A CAMISO foi determinada pelo método up-and-down. Aproximadamente 20 minutos após a administração da CR ou CS, um estímulo nociceptivo (cirúrgico) foi aplicado e a resposta avaliada. A CAMISO foi 0,50±0,01% no CR (n=10) e 0,31±0,04% no CS (n=13). A CAMISO foi 38% menor no CS comparado ao CR. Os resultados deste estudo revelaram que, em cães premedicados com acepromazina e morfina, a administração IM de 3mgkg-1 de cetamina, aproximadamente 20 minutos antes do estímulo nociceptivo, causou redução clinicamente importante na CAMISO e o efeito redutor na CAMISO é significativamente maior com CS do que com CR.

Comparison of clinical and hemodynamic effects of isoflurane and sevoflurane anesthesia in calves

Background: Inhalation anesthesia is the preferred method for use on many animal species, including ruminants, due to its superiority over the injectable anesthetics. The most commonly used inhalation anesthetics are isoflurane and sevoflurane The aim of the study was to investigate the effects of isoflurane and sevoflurane anesthesia on the cardiovascular system of calves.Materials, Methods & Results: A total of 20 calves (11 male, 9 female) between 1 and 6 months in age and 50 to 85 kg in body weight were used. The calves were divided randomly into two groups of 10 each, with one group being administered isoflurane and the other sevoflurane. An intramuscular dosage of 0.1 mg/kg of xylazine was administered to the calves as premedication. Induction was performed 10 min after calves were given an intramuscular dosage of 4 mg/kg of ketamine. Inhalation anesthesia was maintained with isoflurane or sevoflurane in 100% oxygen saturation. Before anesthesia, after induction and at intervals of 5, 10, 15, 20, 25, 30, 45, and 60 min of anesthesia, the body temperature, heart rate, and respiratory rate of the calves were recorded. Additionally, before anesthesia, after induction and at intervals of 15, 30, 45, and 60 min of anesthesia, serum electrolyte (Na+ , Ca++, K+ , Mg++) and blood gases (pH, pCO2 , pO2 , HCO3-, TCO2 , O2 Sat, HCT) were evaluated from blood samples taken from both groups. The second derivation, durations and amplitudes of the P and T waves, the durations and amplitudes of the QRS complex, and the durations of PQ and QT intervals were evaluated on the ECGs recorded before anesthesia, after induction and during anesthesia. Following anesthesia termination, the extubation time and the time it took for straightening of the head and standing up were recorded. Decrease in heart rate and body temperature were found significant in two of the groups.[...](AU)

Comparison of clinical and hemodynamic effects of isoflurane and sevoflurane anesthesia in calves

Background: Inhalation anesthesia is the preferred method for use on many animal species, including ruminants, due to its superiority over the injectable anesthetics. The most commonly used inhalation anesthetics are isoflurane and sevoflurane The aim of the study was to investigate the effects of isoflurane and sevoflurane anesthesia on the cardiovascular system of calves.Materials, Methods & Results: A total of 20 calves (11 male, 9 female) between 1 and 6 months in age and 50 to 85 kg in body weight were used. The calves were divided randomly into two groups of 10 each, with one group being administered isoflurane and the other sevoflurane. An intramuscular dosage of 0.1 mg/kg of xylazine was administered to the calves as premedication. Induction was performed 10 min after calves were given an intramuscular dosage of 4 mg/kg of ketamine. Inhalation anesthesia was maintained with isoflurane or sevoflurane in 100% oxygen saturation. Before anesthesia, after induction and at intervals of 5, 10, 15, 20, 25, 30, 45, and 60 min of anesthesia, the body temperature, heart rate, and respiratory rate of the calves were recorded. Additionally, before anesthesia, after induction and at intervals of 15, 30, 45, and 60 min of anesthesia, serum electrolyte (Na+ , Ca++, K+ , Mg++) and blood gases (pH, pCO2 , pO2 , HCO3-, TCO2 , O2 Sat, HCT) were evaluated from blood samples taken from both groups. The second derivation, durations and amplitudes of the P and T waves, the durations and amplitudes of the QRS complex, and the durations of PQ and QT intervals were evaluated on the ECGs recorded before anesthesia, after induction and during anesthesia. Following anesthesia termination, the extubation time and the time it took for straightening of the head and standing up were recorded. Decrease in heart rate and body temperature were found significant in two of the groups.[...]

Isoflurane MAC determination in dogs using three intensities of constant-current electrical stimulation.

OBJECTIVES: To compare isoflurane minimum alveolar concentrations (MACs) in dogs determined using three intensities of constant-current electrical stimulation applied at the tail, and thoracic and pelvic limbs, and to compare isoflurane MACs obtained with all combinations of electrical stimulation and anatomic site with those obtained using the tail clamp as the noxious stimulus. STUDY DESIGN: Randomized trial. ANIMALS: Six mixed-breed, adult female dogs aged 1-2 years and weighing 11.1 ± 4.4 kg. METHODS: In each dog, MAC was determined by the bracketing method with the tail clamp (MACTAILCLAMP ), and three electrical currents (10 mA, 30 mA, 50 mA) at three anatomic sites (thoracic limb, pelvic limb, tail). Each MAC achieved with electrical stimulation was compared with MACTAILCLAMP using a mixed-model anova and Dunnett's procedure for multiple comparisons. The effects of current intensity and anatomic site on isoflurane MAC were tested using a mixed-model anova followed by Tukey's test for multiple comparisons (p < 0.05). RESULTS: Mean MACTAILCLAMP was 1.69%. MACs achieved with currents of 30 mA and 50 mA did not differ independently of anatomic site. When currents of 10 mA were applied to the tail and thoracic limb, resulting MACs were lower than those obtained using currents of 30 mA and 50 mA. Currents of 30 mA and 50 mA provided MACs that did not differ from those of MACTAILCLAMP , whereas a current of 10 mA achieved the same result only for the pelvic limb. CONCLUSIONS AND CLINICAL RELEVANCE: Isoflurane MAC is affected by current intensity and anatomic site. Current intensities of 30 mA and 50 mA provided consistent results when applied to the tail, and thoracic and pelvic limbs that did not differ from those obtained using the tail clamp. Consequently, they can be used in place of the tail clamp in MAC studies in dogs.

Parâmetros cardiopulmonares e hemogasométricos em ovinos sob anestesia inalatória durante alternâncias de decúbito / Cardiopulmonary and blood gas parameters in sheep under inhalational anesthesia during decubitus alternations

Os rebanhos de ovinos do Centro-Oeste do Brasil, principalmente da raça Santa Inês, aumentaram muito nos últimos anos. Dessa forma, a casuística clínica também cresceu e a realização de cirurgias de grande porte sem dor e com segurança se faz presente, associada ao uso da anestesia geral inalatória. Este trabalho objetivou avaliar os parâmetros cardiopulmonares e hemogasométricos em ovinos sob anestesia inalatória com ventilação controlada, bem como avaliar a influência de alternâncias de decúbito nos mesmos parâmetros. Os animais foram sedados com acepromazina, induzidos com propofol, intubados e colocados sob anestesia inalatória com isoflurano durante manutenção anestésica. As frequências cardíaca e respiratória, pressão arterial e a concentração de gases sanguíneos foram aferidas a cada cinco minutos por um total de 45 minutos, durante os quais os animais foram alternados entre decúbito lateral direito, dorsal e esquerdo. Os parâmetros aferidos não apresentaram diferenças significativas entre os tempos e decúbitos, concluindo-se que a anestesia geral inalatória com isoflurano mostra-se viável e segura na espécie ovina, pois mantém os parâmetros cardiopulmonares e hemogasométricos em níveis seguros

Sheep herds, especially Santa Ines breed, have grown in the Brazilian Midwest in recent years. Therefore, clinical cases have also grown, and along came the need of conducting major surgeries without pain associated with the use of inhalational anesthesia. This study evaluated the cardiopulmonary and blood gas parameters in sheep under inhalational anesthesia with controlled ventilation, and assessed the effect of decubitus alternations on the parameters. The animals were anesthetized with acepromazine and propofol, intubated and placed on inhalational anesthesia with isoflurane. The respiratory rates, blood pressure and blood gas concentrations were measured every for minutes for a total of 45 minutes during which the animals were alternated right, dorsal and left decubitus. The measured parameters showed no significant differences among the times and positions, concluding that inhalational anesthesia with isoflurane is valid and safe for sheep, as it keeps the cardiopulmonary parameters and arterial blood gases at safe levels

Parâmetros cardiopulmonares e hemogasométricos em ovinos sob anestesia inalatória durante alternâncias de decúbito / Cardiopulmonary and blood gas parameters in sheep under inhalational anesthesia during decubitus alternations

Os rebanhos de ovinos do Centro-Oeste do Brasil, principalmente da raça Santa Inês, aumentaram muito nos últimos anos. Dessa forma, a casuística clínica também cresceu e a realização de cirurgias de grande porte sem dor e com segurança se faz presente, associada ao uso da anestesia geral inalatória. Este trabalho objetivou avaliar os parâmetros cardiopulmonares e hemogasométricos em ovinos sob anestesia inalatória com ventilação controlada, bem como avaliar a influência de alternâncias de decúbito nos mesmos parâmetros. Os animais foram sedados com acepromazina, induzidos com propofol, intubados e colocados sob anestesia inalatória com isoflurano durante manutenção anestésica. As frequências cardíaca e respiratória, pressão arterial e a concentração de gases sanguíneos foram aferidas a cada cinco minutos por um total de 45 minutos, durante os quais os animais foram alternados entre decúbito lateral direito, dorsal e esquerdo. Os parâmetros aferidos não apresentaram diferenças significativas entre os tempos e decúbitos, concluindo-se que a anestesia geral inalatória com isoflurano mostra-se viável e segura na espécie ovina, pois mantém os parâmetros cardiopulmonares e hemogasométricos em níveis seguros(AU)

Sheep herds, especially Santa Ines breed, have grown in the Brazilian Midwest in recent years. Therefore, clinical cases have also grown, and along came the need of conducting major surgeries without pain associated with the use of inhalational anesthesia. This study evaluated the cardiopulmonary and blood gas parameters in sheep under inhalational anesthesia with controlled ventilation, and assessed the effect of decubitus alternations on the parameters. The animals were anesthetized with acepromazine and propofol, intubated and placed on inhalational anesthesia with isoflurane. The respiratory rates, blood pressure and blood gas concentrations were measured every for minutes for a total of 45 minutes during which the animals were alternated right, dorsal and left decubitus. The measured parameters showed no significant differences among the times and positions, concluding that inhalational anesthesia with isoflurane is valid and safe for sheep, as it keeps the cardiopulmonary parameters and arterial blood gases at safe levels(AU)

Does occupational exposure to anesthetic gases lead to increase of pro-inflammatory cytokines?

INTRODUCTION: There is great concern about the possible harmful effects of exposure to volatile anesthetics. The current study aimed at evaluating, for the first time, the effects of occupational exposure to anesthetic gases on physicians who work in operating rooms, by determining several inflammatory cytokines. MATERIALS AND METHODS: Plasma inflammatory cytokines (IL-1ß, -6, -8, -10, -12, TNF-α) were investigated in 30 individuals who were allocated into two groups of 15: the exposed group, consisting of operating room medical personnel exposed to a mixture of anesthetic gases for 3 years, and a control group composed of medical personnel not exposed to anesthetic gases. The concentrations of volatile anesthetics were measured in the operating room by means of an infrared portable analyzer RESULTS AND CONCLUSIONS: Our findings suggest an increase of the pro-inflammatory IL-8 (p<0.05) in medical personnel exposed to high concentrations of anesthetic gases, even for a relatively short period.

Lidocaine, dexmedetomidine and their combination reduce isoflurane minimum alveolar concentration in dogs.

The effects of intravenous (i.v.) lidocaine, dexmedetomidine and their combination delivered as a bolus followed by a constant rate infusion (CRI) on the minimum alveolar concentration of isoflurane (MACISO) in dogs were evaluated. Seven healthy adult dogs were included. Anaesthesia was induced with propofol and maintained with isoflurane. For each dog, baseline MAC (MACISO/BASAL) was determined after a 90-minute equilibration period. Thereafter, each dog received one of the following treatments (loading dose, CRI): lidocaine 2 mg kg(-1), 100 µg kg(-1) minute(-1); dexmedetomidine 2 µg kg(-1), 2 µg kg(-1) hour(-1); or their combination. MAC was then determined again after 45- minutes of treatment by CRI. At the doses administered, lidocaine, dexmedetomidine and their combination significantly reduced MACISO by 27.3% (range: 12.5-39.2%), 43.4% (33.3-53.3%) and 60.9% (46.1-78.1%), respectively, when compared to MACISO/BASAL. The combination resulted in a greater MACISO reduction than the two drugs alone. Their use, at the doses studied, provides a clinically important reduction in the concentration of ISO during anaesthesia in dogs.

Efeitos cardiovasculares e respiratórios em cães anestesiados com diferentes concentrações de isoflurano / Cardiovascular and pulmonary effects of different isoflurane concentrations in dogs

No presente trabalho foram analisados os efeitos sobre os aparelhos cardiovascular e respiratório da anestesia inalatória com isoflurano em 3 (três) concentrações fixas (1, 1 ,5 e 2 CAM) no cão. Foram utilizados 6 (seis) cães machos, pesando 25 ± 2, 7 kg, com valores hematológicos e bioquímicas dentro da faixa de normalidade. Os parâmetros analisados foram: frequência cardíaca (FC), pressão arterial sistólica (PS), diastólica (PD) e média (PM), débito cardíaco (DC), índice cardíaco (IC), frequência respiratória (FR),volume corrente (VC) e volume minuto (VM). Observou-se que, baixas concentrações de isoflurano (1 e 1,5 CAM) produziram um aumento de FC. Com relação à pressão arterial, verificou-se um decréscimo dose-dependente, causado pela diminuição da resistência vascular periférica, o que explicaria a manutenção do DC e IC em baixas concentrações (1 e 1,5 CAM). A 2 CAM de concentração, o aumento da FC não foi capaz de compensar o menor volume de ejeção do coração. Devido a isso, observou-se queda do DC e IC. No sistema respiratório, encontrou-se diminuição da FR, VC e VM, dose-dependente.

Cardiovascular and pulmonary effexts of isoflurane anesthesia at 1, 1 ,5 and 2 minimum alveolar concentration (MAC) were studies in 6 male dogs, healty, weighting 25 ± 2.7 kg. Heart rate (HR), systolic arterial pressure (SAP), dyastolic arterial pressure rate (RR), tidal volume (TV) and minute ventilation (MV) were measured. Low isoflurane concentrations (1 and 1,5 MAC) increased the heart rate (HR). Arterial blood pressure decreased as the MAC increased, explaining the maintenance of the CO and the Cl at low concentrations of isoflurane (1 and 1,5 MAC). At 2 MAC the increase of the HR is not enough to compensate the low heart stroke volume, soa drop of CO an Cl was obseved. A dose-dependent decrease of the RR, TV and MV was also obseved.