Influence of Constant Rate Infusions of Fentanyl Alone or in Combination With Lidocaine and Ketamine on the Response to Surgery and Postoperative Pain in Isoflurane Anesthetized Dogs Undergoing Unilateral Mastectomy: A Randomized Clinical Trial.

The aim of this study was to compare the effects of constant rate infusions (CRI) of fentanyl alone or combined with lidocaine and ketamine (FLK), on physiological parameters, isoflurane requirements and the number of postoperative analgesic rescues in dogs undergoing unilateral mastectomy. Twenty-two dogs were premedicated with acepromazine 0.02 mg/kg and morphine 0.5 mg/kg and anesthetized with propofol and isoflurane. Dogs were randomly assigned to 1 of 2 groups: Fentanyl group (fentanyl 5 µg/kg loading dose [LD] and 9 µg/kg/h CRI; n = 11); FLK group (fentanyl [same doses]; lidocaine 2 mg/kg LD and 3 mg/kg/h CRI; ketamine 1.0 mg/kg LD and 0.6 mg/kg/h CRI; = 11). Intraoperative evaluations were performed before the start of surgery and administration of the treatments (T0); three minutes after the LD (T1); during incision and tissue divulsion (T2); during closure of the surgical wound (T3). Meloxicam (0.1 mg/kg) was administered at T3. Blood samples were collected for determination of plasma concentrations of fentanyl, lidocaine and ketamine. Pain scores and the number of postoperative analgesic rescues with morphine (0.5 mg/kg) were evaluated for 24 hours postoperatively using the short form of the Glasgow Composite Measure Pain Scale. Compared to T0, significant decreases in heart rate (from 84 ± 28 to 53 ± 16 bpm in the Fentanyl group and from 93 ± 16 to 63 ± 15 bpm in FLK) and mean arterial pressure (from 61 ± 5 to 49 ± 10 mmHg in Fentanyl and from 59 ± 3 to 38 ± 6 mmHg in FLK) were observed at T1. Arterial hypotension was transient, with normalization of values at T2 and T3. The expired fraction of isoflurane did not differ significantly between the groups. Plasma concentrations of fentanyl, lidocaine and ketamine remained within the therapeutic range. Postoperatively, the number of dogs requiring analgesic rescue was significantly lower in the FLK (0/11, 0%) than in the Fentanyl group (5/11, 45%). In dogs administered morphine and meloxicam as part of the anesthesia protocol, an intraoperative CRI of FLK abolished the requirement for postoperative analgesic rescue for 24 hours in dogs undergoing mastectomy.

Spinal cord injury-related thermoregulatory impairment masks a fatal malignant hyperthermia crisis: a case report.

PURPOSE: Malignant hyperthermia (MH) is a hypermetabolic disorder that can occur in genetically susceptible individuals exposed to halogenated anesthetics and succinylcholine. Spinal cord injury (SCI) above the sixth thoracic vertebra is associated with dysfunction of the sympathetic/parasympathetic nervous pathways, including thermoregulatory dysfunction, presenting as hypothermia in cold environments because of vasodilation and heat loss. This effect could mitigate or obscure an MH episode. Here, we describe development of a fatal MH crisis in a patient with SCI. CLINICAL FEATURES: A 27-yr-old male patient with an SCI after fracture of the sixth cervical vertebra was admitted for spinal arthrodesis. Anesthetic medications included remifentanil, propofol, succinylcholine, rocuronium, and isoflurane. After the start of the surgery, muscular contractures resembling myoclonus were noted, which resolved with pancuronium administration. Four hours after the start of anesthesia, the patient presented with hyperthermia, hypercarbia, hypotension, muscle rigidity, arrhythmia, and cardiogenic shock, with metabolic/respiratory acidosis. Malignant hyperthermia was suspected and the treatment was started, but he developed cardiopulmonary arrest and died an hour and a half after the first cardiac arrest. Both parents were investigated and were found to have normal creatine kinase levels and positive in vitro contracture tests. His mother carried a variant in the ryanodine receptor type 1 (RYR1) gene (c.14918C>T), which is associated with MH. CONCLUSION: Spinal cord injury-induced thermoregulatory dysfunction may obscure the early diagnosis of MH and lead to fatal outcome.

RéSUMé: OBJECTIF: L'hyperthermie maligne est un trouble hypermétabolique qui peut survenir chez les personnes génétiquement susceptibles exposées à des anesthésiques volatils et à la succinylcholine. Les lésions médullaires situées au-dessus de la sixième vertèbre thoracique sont associées à un dysfonctionnement des voies nerveuses sympathiques / parasympathiques, y compris un trouble de la thermorégulation, et se présentent sous forme d'hypothermie dans des environnements froids en raison de la vasodilatation et de la perte de chaleur. Cet effet pourrait atténuer ou occulter un épisode d'hyperthermie maligne. Nous décrivons ici l'apparition d'une crise mortelle d'hyperthermie maligne chez un patient atteint de lésion médullaire. CARACTéRISTIQUES CLINIQUES: Un patient de 27 ans atteint d'une lésion médullaire après une fracture de la sixième vertèbre cervicale a été admis pour une arthrodèse rachidienne. Les médicaments anesthésiques comprenaient du rémifentanil, du propofol, de la succinylcholine, du rocuronium et de l'isoflurane. Après le début de la chirurgie, des contractures musculaires ressemblant à une myoclonie ont été notées, lesquelles se sont résolues avec l'administration de pancuronium. Quatre heures après l'induction d'anesthésie, le patient a présenté une hyperthermie, une hypercarbie, une hypotension, une rigidité musculaire, une arythmie et un choc cardiogénique, avec acidose métabolique / respiratoire. Une hyperthermie maligne a été suspectée et le traitement a été amorcé, mais le patient a subi un arrêt cardiorespiratoire et est décédé une heure et demie après le premier arrêt cardiaque. Les deux parents ont passés des tests et se sont avérés avoir des taux normaux de créatine kinase et des tests de contracture in vitro positifs. La mère du patient était porteuse d'un variant du gène récepteur de ryanodine de type 1 (RYR1) (c.14918C>T), lequel est associé à l'hyperthermie maligne. CONCLUSION: Un trouble de la thermorégulation induit par une lésion médullaire peut masquer un diagnostic précoce d'hyperthermie maligne et entraîner une issue fatale.

An update on the cecectomy technique in roosters anesthetized with isoflurane used in subsequent amino acid digestibility experiments.

This work aims to study an alternative technique of cecectomy in roosters using inhalation anesthesia for subsequent use in digestibility experiments. A total of 30 adult chickens of Leghorn breed were used with an average age of 27 wk. The birds were preoxygenated, and the anesthetic induction was performed using isoflurane diluted in oxygen. After proper muscle relaxation, endotracheal intubation was performed using a Murphy catheter and kept in anesthesia under mechanical ventilation with a constant monitoring of electrocardiography variables, heart rate, oxyhemoglobin saturation, and body temperature during the surgical procedure. An incision of approximately 3 cm was made between keel and cloaca in order to expose and extirpate the cecum followed by a simple ligature. The opening of the peritoneal cavity was closed in 2 ways: Sultan suture technique was used for closing the abdominal wall and modified Cushing intradermic continuous points for closing the skin. The time for anesthesia induction and preoperational period noted to be 10 ± 2 min. Surgical procedures completed in 7 ± 1.5 min. No intraoperatively and postoperatively harm observed in animals. Water was immediately provided after the birds returned to cages and feed offered after 24 h of surgery. In remaining birds, no abnormalities were observed during and after the experimental period (3 mo). The present study describes a promising update on cecectomy technique regarding anesthesia induction and surgical procedures in roosters using potential drugs and safer surgical materials without any trans- and postoperative complications.

Combination of Transversus abdominis plane block and Serratus plane block anesthesia in dogs submitted to masctetomy / Combinação dos bloqueios anestésicos do plano transverso abdominal e do plano serrátil em cadelas submetidas à mastectomia

This paper pretends to demonstrate the effect of the combination of transversus abdominis plane block (TAP block) and Serratus plane block (SP block) techniques in analgesia of 4 dogs undergoing total unilateral mastectomy. Dogs were premedicated with methadone (0.5mg.kg-1) intramuscularly. Anesthesia was induced with propofol (6mg.kg-1) and midazolam (0.3mg.kg-1) and maintained with isoflurane. SP and TAP block were performed unilaterally using ultrasound by the injection of bupivacaine 0.25% (0.3mL kg-1) diluted with NaCl solution 1:1. Heart rate (HR), respiratory rate (f), non-invasive arterial pressure, esophageal temperature (T), oxygen saturation (SpO2) and electrocardiogram were monitored continuously. Animals were monitored for two and four hours after extubation for pain by using the Canine Acute Pain Scale from Colorado State University. Two hours after extubation, tramadol (4mg.kg-1) and dipyrone (25mg.kg-1) was administered to all dogs. It was not observed any alteration on cardiac rhythm. HR, f, T and mean arterial pressure remained below the preincisional values for all dogs. No dog required intraoperative rescue analgesia. Recovery from anesthesia was without any complication. All animals scored 0 (0/5) at pain scale, two and four hours after extubation and none of them expressed concern over the surgical wound. Dogs were able to walk before two hours after extubation. The combination of both techniques is effective in anesthetic blocking the thoracic and abdominal walls and it is suggested both may be included in the multimodal analgesia protocols for this type of surgery.(AU)

Este trabalho pretende demonstrar o efeito analgésico da combinação das técnicas de bloqueio do plano transverso abdominal (TAP block) e bloqueio do plano serrátil (SP block) em 4 cadelas submetidas à mastectomia unilateral total. Os animais foram pré-medicados com metadona (0,5mg.kg-1) por via intramuscular. A anestesia foi induzida com propofol (6mg.kg-1) e midazolam (0,3mg.kg-1) e mantida com isoflurano. Os bloqueios SP e TAP foram realizados unilateralmente, utilizando ultrassonografia, pela injeção de bupivacaína a 0,25% (0,3mL.kg-1), diluída com solução de NaCl a 1:1. A frequência cardíaca (FC), frequência respiratória (f), pressão arterial não invasiva, temperatura esofágica (T), saturação de oxigênio (SpO2) e eletrocardiograma foram monitorados continuamente. Os animais foram monitorizados durante duras e quatro horas após a extubação para a dor usando a Escala de Dor Aguda Canina da Universidade Estadual do Colorado. Duas horas após a extubação, tramadol (4mg.kg-1) e dipirona (25mg.kg-1) foram administrados a todos os cães. Não foi observada qualquer alteração no ritmo cardíaco. HR, f, T e pressão arterial média permaneceram abaixo dos valores basais para todos os cães. Nenhum cão requereu resgate analgésico intra-operatório. Não houve complicações na recuperação anestésica. Todos os animais apresentaram escore 0 (0/5) na escala de dor, duras e 4 quatro horas após a extubação e nenhum expressou desconforto com a ferida cirúrgica. Todos os cães foram capazes de caminhar antes de duas horas após extubação. A combinação de ambas as técnicas é eficaz no bloqueio anestésico das paredes torácica e abdominal e sugere-se que ambos podem ser incluídos nos protocolos de analgesia multimodal para este tipo de cirurgia.(AU)

Combination of Transversus abdominis plane block and Serratus plane block anesthesia in dogs submitted to masctetomy / Combinação dos bloqueios anestésicos do plano transverso abdominal e do plano serrátil em cadelas submetidas à mastectomia

This paper pretends to demonstrate the effect of the combination of transversus abdominis plane block (TAP block) and Serratus plane block (SP block) techniques in analgesia of 4 dogs undergoing total unilateral mastectomy. Dogs were premedicated with methadone (0.5mg.kg-1) intramuscularly. Anesthesia was induced with propofol (6mg.kg-1) and midazolam (0.3mg.kg-1) and maintained with isoflurane. SP and TAP block were performed unilaterally using ultrasound by the injection of bupivacaine 0.25% (0.3mL kg-1) diluted with NaCl solution 1:1. Heart rate (HR), respiratory rate (f), non-invasive arterial pressure, esophageal temperature (T), oxygen saturation (SpO2) and electrocardiogram were monitored continuously. Animals were monitored for two and four hours after extubation for pain by using the Canine Acute Pain Scale from Colorado State University. Two hours after extubation, tramadol (4mg.kg-1) and dipyrone (25mg.kg-1) was administered to all dogs. It was not observed any alteration on cardiac rhythm. HR, f, T and mean arterial pressure remained below the preincisional values for all dogs. No dog required intraoperative rescue analgesia. Recovery from anesthesia was without any complication. All animals scored 0 (0/5) at pain scale, two and four hours after extubation and none of them expressed concern over the surgical wound. Dogs were able to walk before two hours after extubation. The combination of both techniques is effective in anesthetic blocking the thoracic and abdominal walls and it is suggested both may be included in the multimodal analgesia protocols for this type of surgery.(AU)

Este trabalho pretende demonstrar o efeito analgésico da combinação das técnicas de bloqueio do plano transverso abdominal (TAP block) e bloqueio do plano serrátil (SP block) em 4 cadelas submetidas à mastectomia unilateral total. Os animais foram pré-medicados com metadona (0,5mg.kg-1) por via intramuscular. A anestesia foi induzida com propofol (6mg.kg-1) e midazolam (0,3mg.kg-1) e mantida com isoflurano. Os bloqueios SP e TAP foram realizados unilateralmente, utilizando ultrassonografia, pela injeção de bupivacaína a 0,25% (0,3mL.kg-1), diluída com solução de NaCl a 1:1. A frequência cardíaca (FC), frequência respiratória (f), pressão arterial não invasiva, temperatura esofágica (T), saturação de oxigênio (SpO2) e eletrocardiograma foram monitorados continuamente. Os animais foram monitorizados durante duras e quatro horas após a extubação para a dor usando a Escala de Dor Aguda Canina da Universidade Estadual do Colorado. Duas horas após a extubação, tramadol (4mg.kg-1) e dipirona (25mg.kg-1) foram administrados a todos os cães. Não foi observada qualquer alteração no ritmo cardíaco. HR, f, T e pressão arterial média permaneceram abaixo dos valores basais para todos os cães. Nenhum cão requereu resgate analgésico intra-operatório. Não houve complicações na recuperação anestésica. Todos os animais apresentaram escore 0 (0/5) na escala de dor, duras e 4 quatro horas após a extubação e nenhum expressou desconforto com a ferida cirúrgica. Todos os cães foram capazes de caminhar antes de duas horas após extubação. A combinação de ambas as técnicas é eficaz no bloqueio anestésico das paredes torácica e abdominal e sugere-se que ambos podem ser incluídos nos protocolos de analgesia multimodal para este tipo de cirurgia.(AU)

Avaliação da dexmedetomidina e do tramadol, associados ao midazolam, em gatas anestesiadas com isoflurano e submetidas à ovário-histerectomia / Evaluation of dexmedetomidine and tramadol, associated with midazolam, in cats anesthetized with isoflurane, undergoing ovariohysterectomy

Objetivou-se comparar as alterações cardiorrespiratórias e a analgesia pós-operatória promovidas pela dexmedetomidina e pelo tramadol, quando associados ao midazolam, em felinas. Para tal, foram selecionadas 18 gatas hígidas, divididas em dois grupos randomizados: GDM, tratadas com dexmedetomidina (10µg/kg) e GTM, tratadas com tramadol (2mg/kg), ambos associados a midazolam (0,2mg/kg,) IM. Após 15 minutos, procedeu-se à indução anestésica com propofol (1,46±0,79mL), mantendo-se a anestesia com isoflurano. As felinas foram submetidas à ovário-histerectomia, registrando-se as variáveis cardiorrespiratórias 15 minutos após a MPA (M0), 15 minutos após a indução (M15) e sequencialmente a cada cinco minutos, até o término do procedimento cirúrgico (M20, M25, M30, M35 e M40). A avaliação da dor iniciou-se 30 minutos após o término do procedimento cirúrgico (MP30) e sequencialmente em intervalos de 30 minutos (MP60, MP90, MP120). A partir do MP120, as avaliações foram registradas a cada hora (MP180, MP240 e MP360). A associação dexmedetomidina-midazolam infere diminuição inicial de frequência cardíaca (FC) sem significado clínico e está relacionada à sedação mais pronunciada, à analgesia menor e menos duradoura e a episódios de êmese, quando comparada à associação tramadol-midazolam. Ambos os protocolos denotaram estabilidade cardiorrespiratória e podem ser considerados seguros em felinas submetidas à ovário-histectomia.(AU)

The aim of this study was to compare cardiorespiratory changes and post-operative analgesia provided by dexmedetomidine or tramadol, associated with midazolam, in female cats. For that purpose, 18 healthy cats were assigned to two randomized groups: GDM, which received dexmedetomidine (10 µg/kg) and GTM, which received tramadol (2 mg/kg), both associated with midazolam (0.2 mg/kg) IM. After 15 minutes, anesthesia was induced with propofol (1.46±0.79 mL) and maintained with isofluorane. Ovariohysterectomy was performed and cardiorespiratory variables were registered 15 minutes after pre-anesthetic medication (M0), 15 minutes after anesthetic induction (M15), and every five minutes until the end of the surgical procedure (M20, M25, M30, M35 e M40). Pain evaluation started 30 minutes after the surgery (MP30) and sequentially at thirty-minute intervals (MP60, MP90, MP120). After MP120, each evaluation was registered at every hour (MP180, MP240 e MP360). Dexmedetomidine-midazolam association results in decreases on initial heart rate (HR) without clinical relevance and it is related to pronounced sedation, poor and less durable antinociception and vomiting events, when compared to tramadol-midazolam association. Both protocols indicate cardiorespiratoy stability and safety in cats undergoing ovariohysterectomy.(AU)

Avaliação da dexmedetomidina e do tramadol, associados ao midazolam, em gatas anestesiadas com isoflurano e submetidas à ovário-histerectomia / Evaluation of dexmedetomidine and tramadol, associated with midazolam, in cats anesthetized with isoflurane, undergoing ovariohysterectomy

Objetivou-se comparar as alterações cardiorrespiratórias e a analgesia pós-operatória promovidas pela dexmedetomidina e pelo tramadol, quando associados ao midazolam, em felinas. Para tal, foram selecionadas 18 gatas hígidas, divididas em dois grupos randomizados: GDM, tratadas com dexmedetomidina (10µg/kg) e GTM, tratadas com tramadol (2mg/kg), ambos associados a midazolam (0,2mg/kg,) IM. Após 15 minutos, procedeu-se à indução anestésica com propofol (1,46±0,79mL), mantendo-se a anestesia com isoflurano. As felinas foram submetidas à ovário-histerectomia, registrando-se as variáveis cardiorrespiratórias 15 minutos após a MPA (M0), 15 minutos após a indução (M15) e sequencialmente a cada cinco minutos, até o término do procedimento cirúrgico (M20, M25, M30, M35 e M40). A avaliação da dor iniciou-se 30 minutos após o término do procedimento cirúrgico (MP30) e sequencialmente em intervalos de 30 minutos (MP60, MP90, MP120). A partir do MP120, as avaliações foram registradas a cada hora (MP180, MP240 e MP360). A associação dexmedetomidina-midazolam infere diminuição inicial de frequência cardíaca (FC) sem significado clínico e está relacionada à sedação mais pronunciada, à analgesia menor e menos duradoura e a episódios de êmese, quando comparada à associação tramadol-midazolam. Ambos os protocolos denotaram estabilidade cardiorrespiratória e podem ser considerados seguros em felinas submetidas à ovário-histectomia.(AU)

The aim of this study was to compare cardiorespiratory changes and post-operative analgesia provided by dexmedetomidine or tramadol, associated with midazolam, in female cats. For that purpose, 18 healthy cats were assigned to two randomized groups: GDM, which received dexmedetomidine (10 µg/kg) and GTM, which received tramadol (2 mg/kg), both associated with midazolam (0.2 mg/kg) IM. After 15 minutes, anesthesia was induced with propofol (1.46±0.79 mL) and maintained with isofluorane. Ovariohysterectomy was performed and cardiorespiratory variables were registered 15 minutes after pre-anesthetic medication (M0), 15 minutes after anesthetic induction (M15), and every five minutes until the end of the surgical procedure (M20, M25, M30, M35 e M40). Pain evaluation started 30 minutes after the surgery (MP30) and sequentially at thirty-minute intervals (MP60, MP90, MP120). After MP120, each evaluation was registered at every hour (MP180, MP240 e MP360). Dexmedetomidine-midazolam association results in decreases on initial heart rate (HR) without clinical relevance and it is related to pronounced sedation, poor and less durable antinociception and vomiting events, when compared to tramadol-midazolam association. Both protocols indicate cardiorespiratoy stability and safety in cats undergoing ovariohysterectomy.(AU)

Avaliação do fluxo de saída do ventrículo esquerdo em gatos anestesiados submetidos ao pneumoperitônio e à posição deTrendelenburg / Evaluation left ventricle Outflow in cats anesthetized submitted to pneumoperitoneum and Trendelenburg position

Objetivou-se avaliar os efeitos do pneumoperitônio e da posição de Trendelenburg sobre o fluxo de saída do ventrículo esquerdo em gatos anestesiados. Quatorze gatos foram alocados aleatoriamente em dois grupos, ambos submetidos ao pneumoperitônio com 10mmHg de dióxido de carbono (CO2). No grupo controle (GC n=7), os animais foram submetidos apenas ao pneumoperitônio e, no grupo Trendelenburg (GTREN n=7), os animais foram colocados em cefalodeclive 20° após o pneumoperitônio. A indução anestésica foi realizada com isoflurano, utilizando-se caixa de indução. Posteriormente, os animais foram mantidos sob anestesia inalatória com o mesmo fármaco. Foram avaliados a velocidade do fluxo de saída do ventrículo esquerdo (VFSVE), os gradientes máximo (GmáxSVE) e médio (GmédSVE) de pressão e a integral velocidade-tempo (IVT). Os parâmetros foram mensurados nos momentos T0 (basal), antes da insuflação; T5 (cinco), T15 (quinze) e T30 (trinta) minutos após a insuflação. Os resultados mostraram um aumento da VFSVE no GC, em T15 e T30 (P=0,024), e um aumento do GmáxSVE no GC, em T30 (P=0,045). As variáveis não se alteraram significativamente em nenhum momento no GTREN. Dessa forma, conclui-se que a posição de Trendelenburg favoreceu o sistema cardiovascular, preservando os índices de fluxo sanguíneo na saída do ventrículo esquerdo.(AU)

The aim of this study was to evaluate the effects of pneumoperitoneum and Trendelenburg position on the left ventricular outflow in anesthetized cats. Fourteen cats were randomly divided into two groups, both submitted to pneumoperitoneum of 10 mmHg with carbon dioxide (CO2), and in the control group (GC n = 7) the animals were subjected only to pneumoperitoneum and the Trendelenburg group (n = 7 GTREN) the animals were placed in cefalodeclive 20° after pneumoperitoneum. Anesthesia of the animals was performed with isoflurane using induction box, keeping the animals under inhalation anesthesia with the same drug. We evaluated the speed of the left ventricular outflow (VFSVE), the maximum pressure gradient (GmáxSVE), mean pressure gradient (GmédSVE) and velocity-time integrals (IVT). The parameters were measured in time, T0 (baseline), before the insufflation; T5 (five); T15 (fifteen) and T30 (thirty) minutes after inflation. The results showed an increase in VFSVE in GC, T15 and T30 (p = 0,024) and an increase in GmáxSVE in GC in T30 (p = 0,045). The variables did not change significantly at any time in GTREN. Thus, it is concluded that the Trendelenburg position favored the cardiovascular system, preserving blood flow rates in the left ventricular outflow.(AU)

Avaliação do fluxo de saída do ventrículo esquerdo em gatos anestesiados submetidos ao pneumoperitônio e à posição deTrendelenburg / Evaluation left ventricle Outflow in cats anesthetized submitted to pneumoperitoneum and Trendelenburg position

Objetivou-se avaliar os efeitos do pneumoperitônio e da posição de Trendelenburg sobre o fluxo de saída do ventrículo esquerdo em gatos anestesiados. Quatorze gatos foram alocados aleatoriamente em dois grupos, ambos submetidos ao pneumoperitônio com 10mmHg de dióxido de carbono (CO2). No grupo controle (GC n=7), os animais foram submetidos apenas ao pneumoperitônio e, no grupo Trendelenburg (GTREN n=7), os animais foram colocados em cefalodeclive 20° após o pneumoperitônio. A indução anestésica foi realizada com isoflurano, utilizando-se caixa de indução. Posteriormente, os animais foram mantidos sob anestesia inalatória com o mesmo fármaco. Foram avaliados a velocidade do fluxo de saída do ventrículo esquerdo (VFSVE), os gradientes máximo (GmáxSVE) e médio (GmédSVE) de pressão e a integral velocidade-tempo (IVT). Os parâmetros foram mensurados nos momentos T0 (basal), antes da insuflação; T5 (cinco), T15 (quinze) e T30 (trinta) minutos após a insuflação. Os resultados mostraram um aumento da VFSVE no GC, em T15 e T30 (P=0,024), e um aumento do GmáxSVE no GC, em T30 (P=0,045). As variáveis não se alteraram significativamente em nenhum momento no GTREN. Dessa forma, conclui-se que a posição de Trendelenburg favoreceu o sistema cardiovascular, preservando os índices de fluxo sanguíneo na saída do ventrículo esquerdo.(AU)

The aim of this study was to evaluate the effects of pneumoperitoneum and Trendelenburg position on the left ventricular outflow in anesthetized cats. Fourteen cats were randomly divided into two groups, both submitted to pneumoperitoneum of 10 mmHg with carbon dioxide (CO2), and in the control group (GC n = 7) the animals were subjected only to pneumoperitoneum and the Trendelenburg group (n = 7 GTREN) the animals were placed in cefalodeclive 20° after pneumoperitoneum. Anesthesia of the animals was performed with isoflurane using induction box, keeping the animals under inhalation anesthesia with the same drug. We evaluated the speed of the left ventricular outflow (VFSVE), the maximum pressure gradient (GmáxSVE), mean pressure gradient (GmédSVE) and velocity-time integrals (IVT). The parameters were measured in time, T0 (baseline), before the insufflation; T5 (five); T15 (fifteen) and T30 (thirty) minutes after inflation. The results showed an increase in VFSVE in GC, T15 and T30 (p = 0,024) and an increase in GmáxSVE in GC in T30 (p = 0,045). The variables did not change significantly at any time in GTREN. Thus, it is concluded that the Trendelenburg position favored the cardiovascular system, preserving blood flow rates in the left ventricular outflow.(AU)

The effects of anesthetic regimen in 90% hepatectomy in rats.

PURPOSE: To evaluate the influence of the anesthetic regimen on anesthetic recovery, survival, and blood glucose levels following a 90% partial hepatectomy in rats. METHODS: Thirty adult male Wistar rats were divided into two groups according to their anesthetic regimens: intraperitoneal ketamine and xylazine or inhaled isoflurane. In order to prevent hypoglycemia, glucose was administered intraperitoneally and glucose (20%) was added to the drinking water. RESULTS: Anesthetic recovery time was longer in the ketamine and xylazine group. The survival rate after 72 hours was lower (log rank=0.0001) in the ketamine and xylazine group (0.0%) than in the isoflurane group (26.7%). The blood glucose after six hours was lower (p=0.017) in the ketamine and xylazine group (63 ± 31.7 mg/dL) than in the isoflurane group (98 ± 21.2 mg/dL). The prolonged anesthesia recovery time associated with ketamine and xylazine decreased the survival rate and blood glucose levels after 90% hepatectomy. CONCLUSION: Isoflurane anesthesia reduced the recovery time and incidence of hypoglycemia and increased the survival rate in the early hours, providing a therapeutic window that is suitable for experimental studies.

Efeitos de misoprostol sublingual pré-operatório no tônus uterino durante anestesia com isoflurano para cesariana / Effects of preoperative sublingual misoprostol on uterine tone during isoflurane anesthesia for cesarean section / Efectos del misoprostol sublingual preoperatorio en el tono uterino durante la anestesia con isoflurano para cesárea

JUSTIFICATIVA E OBJETIVOS: Misoprostol reduz o sangramento uterino após o parto cesáreo sem efeitos prejudiciais para a mãe ou o bebê. Nosso objetivo foi avaliar os efeitos de misoprostol pré-operatório no sangramento materno e no tônus uterino e a necessidade de ocitocina após cesariana sob anestesia com isoflurano. MÉTODOS: Depois da aprovação pelo Comitê de Ética, 366 pacientes programadas para cesariana eletiva foram randomicamente designadas para receber 400 µg de misoprostol sublingual (n = 179) ou um comprimido de placebo (n = 187) após intubação. A anestesia foi mantida com CAM de isoflurano a 0,5-0,7 e óxido nitroso. Todas as pacientes receberam infusão de ocitocina (10 UI) após expulsão da placenta. A estimativa de perda sanguínea, do tônus uterino, da necessidade de ocitocina complementar, da contagem de hematócrito, dos escores de Apgar no 1º e aos 5 minutos e os efeitos adversos foram registrados. RESULTADOS: Após a indução, as pacientes que receberam misoprostol sublingual tiveram perda sanguínea perioperatória (202 ± 383,1 vs 708 ± 204,3 mL, p < 0,001), necessidade de ocitocina (p < 0,001), níveis mais elevados de hematócrito (p < 0,001) e tônus uterino (p < 0,02) menos significativos. A incidência de tremores foi maior no grupo misoprostol (p = 0,04). Não houve diferenças entre os dois grupos quanto aos índices de Apgar, náusea e vômito, distúrbios gastrointestinais e febre. CONCLUSÃO: A administração pré-operatória de misoprostol sublingual (400 µg) é segura e eficaz para atenuar o sangramento materno e o efeito no tônus uterino da anestesia com isoflurano em parto cesário.

BACKGROUND AND OBJECTIVES: Misoprostol would reduce the uterine bleeding after cesarean delivery without harmful effects on either mother or baby. We aimed to evaluate the effects of preoperative misoprostol on maternal blood loss, uterine tone, and the need for additional oxytocin after cesarean delivery under isoflurane anesthesia. METHODS: After ethical approval, 366 patients scheduled for elective cesarean delivery were randomly allocated to receive either sublingual misoprostol 400 µg (n = 179) or placebo tablet (n = 187) after intubation. Anesthesia was maintained with 0.5-0.7 MAC isoflurane with nitrous oxide. All patients received intravenous infusion of 10 IU of oxytocin after placental delivery. Perioperative estimated blood loss, uterine tone, need for supplementary oxytocin, hematocrit, Apgar scores at 1 and 5 min and adverse effects were recorded. RESULTS: After induction, patients receiving sublingual misoprostol had significant less perioperative estimated blood loss (202 ± 383.1 vs. 708 ± 204.3 mL, p < 0.001), need for oxytocin (p < 0.001), higher hematocrit levels (p < 0.001) and uterine tone (p < 0.02). The incidence of shivering was higher in the misoprostol group (p = 0.04). There were no differences between the two groups as regarding Apgar scores, nausea and vomiting, gastrointestinal disturbances and pyrexia. CONCLUSION: Preoperative administration of sublingual misoprostol 400 µg is safe and effective in attenuating the maternal bleeding and uterine atony from isoflurane anesthesia for cesarean delivery.

JUSTIFICATIVA Y OBJETIVOS: El Misoprostol reduce el sangramiento uterino después del parto por cesárea sin efectos perjudiciales para la madre o el bebé. Nuestro objetivo fue evaluar los efectos del misoprostol preoperatorio en el sangramiento materno y en el tono uterino, y la necesidad de ocitocina después de la cesárea bajo anestesia con isoflurano. MÉTODOS: Después de la aprobación por el Comité de Ética, 366 pacientes programadas para la cesárea electiva, fueron randómicamente designadas para recibir 400 µg de misoprostol sublingual (n = 179) o un comprimido de placebo (n = 187) después de la intubación. La anestesia se mantuvo con CAM de isoflurano a 0,5-0,7 y óxido nitroso. Todas las pacientes recibieron una infusión de ocitocina (10 UI) después de la expulsión de la placenta. La estimación de la pérdida sanguínea, del tono uterino, de la necesidad de ocitocina complementaria, del conteo de hematocrito, de los puntajes de Apgar en el 1º y a los 5 minutos y los efectos adversos fueron todos registrados. RESULTADOS: Después de la inducción, las pacientes que recibieron misoprostol sublingual tuvieron una pérdida sanguínea perioperatoria (202 ± 383,1 vs 708 ± 204,3 mL, p < 0,001), necesidad de ocitocina (p < 0,001), niveles más elevados de hematocrito (p < 0,001) y tonouterino (p < 0,02) menos significativos. La incidencia de temblores fue mayor en el grupo misoprostol (p = 0,04). No se registraron diferencias entre los dos grupos en cuanto a los índices de Apgar, náusea y vómito, trastornos gastrointestinales y fiebre. CONCLUSIONES: La administración preoperatoria de misoprostol sublingual (400 µg) es segura y eficaz para atenuar el sangramiento materno y el efecto en el tono uterino de la anestesia con isoflurano en el parto por cesárea.

The effects of anesthetic regimen in 90% hepatectomy in rats / Os efeitos do regime anestésico na hepatectomia de 90% em ratos

PURPOSE: To evaluate the influence of the anesthetic regimen on anesthetic recovery, survival, and blood glucose levels following a 90% partial hepatectomy in rats. METHODS: Thirty adult male Wistar rats were divided into two groups according to their anesthetic regimens: intraperitoneal ketamine and xylazine or inhaled isoflurane. In order to prevent hypoglycemia, glucose was administered intraperitoneally and glucose (20%) was added to the drinking water. RESULTS: Anesthetic recovery time was longer in the ketamine and xylazine group. The survival rate after 72 hours was lower (log rank=0.0001) in the ketamine and xylazine group (0.0%) than in the isoflurane group (26.7%). The blood glucose after six hours was lower (p=0.017) in the ketamine and xylazine group (63±31.7 mg/dL) than in the isoflurane group (98±21.2 mg/dL). The prolonged anesthesia recovery time associated with ketamine and xylazine decreased the survival rate and blood glucose levels after 90% hepatectomy. CONCLUSION: Isoflurane anesthesia reduced the recovery time and incidence of hypoglycemia and increased the survival rate in the early hours, providing a therapeutic window that is suitable for experimental studies.

OBJETIVO: Avaliar a influência do regime anestésico sobre a recuperação anestésica, a sobrevida em 72 horas e a glicemia após hepatectomia parcial de 90% em ratos. MÉTODOS: Trinta ratos Wistar machos adultos foram distribuídos em dois grupos conforme o regime anestésico: combinação de ketamina e xilazina intraperitoneal ou isoflurano inalatório. Para prevenção de hipoglicemia foi administrada glicose intraperitoneal e adicionado glicose (20%) na água de beber. RESULTADOS: A recuperação anestésica no grupo ketamina e xilazina foi mais prolongada. Durante primeira hora após hepatectomia, nenhum rato anestesiado com ketamina e xilazina despertou. Todos do grupo isoflurano estavam ativos minutos após final da cirurgia. A sobrevida em 72 horas foi menor (Log rank=0,0001) no grupo ketamina e xilazina (0,0%) que no grupo isoflurano (26,7%). Glicemia em 6 horas do grupo ketamina e xilazina (63±31,7 mg/dL) foi menor (p=0,017) que no grupo isoflurano (98 ±21,2 mg/dL). Prolongado tempo de recuperação anestésica com ketamina e xilazina diminuiu sobrevida e glicemia após hepatectomia 90%. CONCLUSÃO: Anestesia com isoflurano reduziu tempo de recuperação e hipoglicemia, além de aumentar a sobrevida nas primeiras horas, possibilitando uma janela terapêutica adequada para estudos experimentais.

Effects of preoperative sublingual misoprostol on uterine tone during isoflurane anesthesia for cesarean section.

BACKGROUND AND OBJECTIVES: Misoprostol would reduce the uterine bleeding after cesarean delivery without harmful effects on either mother or baby. We aimed to evaluate the effects of preoperative misoprostol on maternal blood loss, uterine tone, and the need for additional oxytocin after cesarean delivery under isoflurane anesthesia. METHODS: After ethical approval, 366 patients scheduled for elective cesarean delivery were randomly allocated to receive either sublingual misoprostol 400µg (n=179) or placebo tablet (n=187) after intubation. Anesthesia was maintained with 0.5-0.7 MAC isoflurane with nitrous oxide. All patients received intravenous infusion of 10IU of oxytocin after placental delivery. Perioperative estimated blood loss, uterine tone, need for supplementary oxytocin, hematocrit, Apgar scores at 1 and 5 min and adverse effects were recorded. RESULTS: After induction, patients receiving sublingual misoprostol had significant less perioperative estimated blood loss (202±383.1 vs. 708±204.3mL, p<0.001), need for oxytocin (p<0.001), higher hematocrit levels (p<0.001) and uterine tone (p<0.02). The incidence of shivering was higher in the misoprostol group (p=0.04). There were no differences between the two groups as regarding Apgar scores, nausea and vomiting, gastrointestinal disturbances and pyrexia. CONCLUSION: Preoperative administration of sublingual misoprostol 400µg is safe and effective in attenuating the maternal bleeding and uterine atony from isoflurane anesthesia for cesarean delivery.

Comparación de dos técnicas anestésicas: intravenosa total con propofol-remifentanilo vs. general balanceada con isoflurano-remifentanilo para colecistectomía laparoscópica en el Hospital Nacional Cayetano Heredia, enero a marzo 2008 / Comparison of two anesthetic techniques: intravenous total with propofol-remifentanil vs. balanced General with isoflurane-remifentanil for Hospital Nacional Cayetano Heredia laparoscopic cholecystectomy, January to March 2008

Objetivos: Evaluar los efectos de dos técnicas anestésicas sobre: los parámetros hemodinámicos y ventilatorios durante el transoperatorio; la recuperación anestésica; y el dolor postoperatorio. Material y Métodos: Estudio observacional, analítico y prospectivo realizado en pacientes programados para colecistectomía laparoscópica en el Hospital Nacional Cayetano Heredia entre enero a marzo del 2008, quienes recibieron anestesia intravenosa total con propofol-remifentanilo (Grupo 1, n = 20) o anestesia general balanceada con saturación de oxígeno y dióxido de carbono espirado; los tiempos de ventilación, apertura ocular, extubación y para alcanzar el estado de alerta; y la escala visual análoga (EVA). Resultados: Las variables hemodinámicas y ventilatorias fueron similares en ambos grupos. No hubo diferencias en los tiempos de ventilación y apertura ocular. El tiempo de extubación fue menor en el grupo 2 (7.32±2.3 min vs. 6.17±1.2, p<0.05). El tiempo para alcanzar el estado de alerta fue el más corto en el grupo 1 (9.17 vs. 11.32min, p<0.05). No se encontraron diferencias en los valores de EVA entre ambos grupos. Conclusiones: La anestesia intravenosa total y la general balanceada proporcionan una similar y óptima estabilidad hemodinámica y ventilatoria.

Remifentanil, isoflurane, and preconditioning attenuate renal ischemia/reperfusion injury in rats.

BACKGROUND: The purpose of this investigation was to examine the effect of isoflurane, remifentanil, and preconditioning in renal ischemia/reperfusion injury (IRI). METHODS: All 52 male Wistar rats were anesthetized with isoflurane, intubated and mechanically ventilated. The animals were randomly divided into: S group (sham; n = 11) that underwent only right nephrectomy; as well as the I group of right nephrectomy and ischemia for 45 minutes by clamping of left renal artery. (n = 11); the IP (n = 9), the R (n = 10), and the RP (n = 11) groups. In addition, the R and RP animals received remifentanil (2 microg.kg(-1).min(-1)) during the entire experiment. The IP and RP group underwent ischemic preconditioning (IPC = three cycles of 5 minutes). Serum creatinine values were determined before and after IRI, as well as 24 hours later. In addition to an Histological study, cells from the left kidney were evaluated for apoptosis by flow cytometry (FCM). RESULTS: The Creatinine value of 0.8 +/- 0.2 mg/dl in the S group was significantly lower at 24 hours than the I 3.9 +/- 1.5 mg/dl; IP 2.6 +/- 1.7 mg/dl; R 3.3 +/- 2.8 mg/dl; or RP 1.8 +/- 0.5 mg/dl groups. The RP group value was significantly lower than those of the I, IP, and R groups (p < 0.05). The S group showed less proximal tubular cell damage than the I, IP, R, and RP groups (p < 0.05). The percentages of apoptotic cells (FITC(+)/PI(-)) were: S group = 11.6 +/- 6.5; I = 16.7 +/- 7.3; IP = 37.0 +/- 28.4; R = 11.7 +/- 6.6, and RP = 8.8 +/- 1.5. The difference between the IP vs RP group was significant. Similar percentages of necrotic cells (FITC(+)/PI(+)) and intact cells (FITC(-)/PI(-)) were observed among the groups. CONCLUSIONS: Ischemic preconditioning showed no protective effect in the isoflurane group (IP) but when isoflurane was administered associated with remifentanil (RP), there was a beneficial effect on the kidney, as demonstrated by flow cytometry and serum creatinine values.

Does the choice of the halogenated anesthetic influence renal function during hemorrhagic shock and resuscitation?

INTRODUCTION: Halogenated anesthetics can cause changes in the variables that modify the cardiac output necessary to maintain renal hemodynamic during hemorrhagic shock and resuscitation. However, halogenated anesthetics seem to protect against renal ischemia-reperfusion injury. In a model of pressure-guided hemorrhagic shock in dogs, we studied the comparative effects of three halogenated anesthetics-halothane, sevoflurane, and isoflurane-at equipotent concentrations on renal responses after resuscitation. METHODS: Thirty dogs were anesthetized with 1.0 minimum alveolar anesthetic concentration (MAC) of halothane, sevoflurane, or isoflurane. The dogs were splenectomized and hemorrhaged to hold mean arterial pressure at 40-50 mm Hg over 45 min and then resuscitated with the shed blood volume. Hemodynamic variables were measured at baseline, after 45 min of hemorrhage, and 15 and 60 min after resuscitation. Renal variables were measured at baseline and 15 and 60 min after resuscitation. RESULTS: Hemorrhage induced reductions of mean arterial pressure, filling pressures, and cardiac index (p < 0.05), without significant differences among groups (p > 0.05). After 60 min of shed blood replacement, all groups restored hemodynamic and renal variables to the prehemorrhage levels (p > 0.05), without significant differences among groups (p > 0.05), with the exception of sodium fractional excretion, the values for which were significantly higher in isoflurane group, in relation to the other groups after 15 min of re-transfusion (p < 0.05), and renal vascular resistance, the values for which remain lower than baseline in halothane group (p < 0.05). CONCLUSIONS: We conclude that no difference could be detected between choosing equipotent doses of halothane, sevoflurane, or isoflurane in relation to renal variables in dogs submitted to pressure-adjusted hemorrhagic shock and resuscitation.

Comparación del efecto cardioprotector del preacondicionamiento farmacológico con anestésicos halogenados: sevoflurano versus isoflurano in vivo / Comparison of the cardioprotective effect of Pharmacological preconditioning with halogenated anaesthetic agents:: sevofluorane vs isofluorane in vivo

Fundamento: los anestésicos halogenados inducen preacondicionamiento y se utilizan en cirugía cardíaca. Muestran diferente poder preacondicionador, lo que se adjudica en parte a sus propiedades fisicoquímicas, al modelo animal utilizado y a su uso en distintas concentraciones. Objetivo: generar estrategias aplicables de protección frente al daño isquemia-reperfusión miocárdica. Comparar el efecto preacondicionador de sevoflurano e isoflurano in vivo. Material y método: estudiamos cuatro grupos de seis ratas cada uno (n = 24). Se utilizó un modelo en rata Wistar de isquemia-reperfusión miocárdica mediante infarto por ligadura de la arteria coronaria izquierda. Se realiza monitoreo hemodinámico y electrocardiograma (ECG) continuo, tinción histológica de área de infarto y en riesgo de infarto. El preacondicionamiento isquémico se realizó mediante ligadura seriada intermitente de la arteria coronaria izquierda previa al episodio de infarto de 30 minutos de duración; el preacondicionamiento farmacológico se realiza por exposición intermitente a halogenados previo a evento de infarto: 1 MAC de isoflurano y sevoflurano. Se comparan resultados con control. Resultados: se expresan como porcentaje del área de infarto isquémico (15,8±3,1); sevoflurano (21,8±1,3); isoflurano (28,3±1,3). Punta-control (41,3±2,0); preacondicionamiento en relación con el área de riesgo de infarto (media ± desvío estándar). Las zonas donde fue más evidente el fenómeno fueron: centro-control (33,7±2,2); preacondicionamiento isquémico (18,5±1,4); sevoflurano (26,5±1,9); isoflurano (33,9±2,3). Hubo significación con p<0,05 (ANOVA - Bonferroni) para todos los grupos entre sí. Conclusiones: el sevoflurano fue más efectivo que el isoflurano en la protección frente al daño por isquemia reperfusión. El preacondicionamiento isquémico mostró mayor protección que ambos halogenados.

Comparación del efecto cardioprotector del preacondicionamiento farmacológico con anestésicos halogenados: sevoflurano versus isoflurano in vivo / Comparison of the cardioprotective effect of pharmacological preconditioning with halogenated anaesthetic agents: sevofluorane vs isofluorane in vivo

Fundamento: los anestésicos halogenados inducen preacondicionamiento y se utilizan en cirugía cardíaca. Muestran diferente poder preacondicionador, lo que se adjudica en parte a sus propiedades fisicoquímicas, al modelo animal utilizado y a su uso en distintas concentraciones. Objetivo: generar estrategias aplicables de protección frente al daño isquemia-reperfusión miocárdica. Comparar el efecto preacondicionador de sevoflurano e isoflurano in vivo. Material y método: estudiamos cuatro grupos de seis ratas cada uno (n = 24). Se utilizó un modelo en rata Wistar de isquemia-reperfusión miocárdica mediante infarto por ligadura de la arteria coronaria izquierda. Se realiza monitoreo hemodinámico y electrocardiograma (ECG) continuo, tinción histológica de área de infarto y en riesgo de infarto. El preacondicionamiento isquémico se realizó mediante ligadura seriada intermitente de la arteria coronaria izquierda previa al episodio de infarto de 30 minutos de duración; el preacondicionamiento farmacológico se realiza por exposición intermitente a halogenados previo a evento de infarto: 1 MAC de isoflurano y sevoflurano. Se comparan resultados con control. Resultados: se expresan como porcentaje del área de infarto isquémico (15,8±3,1); sevoflurano (21,8±1,3); isoflurano (28,3±1,3). Punta-control (41,3±2,0); preacondicionamiento en relación con el área de riesgo de infarto (media ± desvío estándar). Las zonas donde fue más evidente el fenómeno fueron: centro-control (33,7±2,2); preacondicionamiento isquémico (18,5±1,4); sevoflurano (26,5±1,9); isoflurano (33,9±2,3). Hubo significación con p<0,05 (ANOVA - Bonferroni) para todos los grupos entre sí. Conclusiones: el sevoflurano fue más efectivo que el isoflurano en la protección frente al daño por isquemia reperfusión. El preacondicionamiento isquémico mostró mayor protección que ambos halogenados.

Background: halogenated anesthetics induce preconditioning and are used in cardiac surgery. They show different preconditioning effect, in part due to their distinct physical and chemical properties, animal model chosen and different concentrations, utilized.Objectives: To develop applicable strategies of myocardial protection against ischemia-reperfusion injury. To compare the preconditioning effect of sevoflurane and isoflurane in vivo. Methods: four groups of 6 Wistar rats each (n=24) were studied using a myocardial ischemia-reperfusion model with infarct produced by occlusion of the left coronary artery. Continuous hemodynamic and electrocardiographic monitoring, and histological staining of infarct and at-risk areas were performed. Ischemic preconditioning was performed by intermittent serial occlusion of the left coronary artery before the 30-minute infarct occlusion; pharmacological preconditioning was performed by intermittent exposure to volatile anesthetic before the infarct: 1 Minimal Alveolar Concentration of isoflurane and sevoflurane. Results were compared with control. Results: they are expressed as percentage of infarct area in relation to area at risk (mean ± standard deviation). Preconditioning was more evident in these areas: center- control (33,7±2,2); ischemic preconditioning (15,8±3,1); sevoflurane (21,8±1,3); isoflurane (28,3±1,3). apex- control (41,3±2,0); ischemic preconditioning (18,5±1,4); sevoflurane (26,5±1,9); isoflurane (33,9±2,3). Statistically significant differences were found between all groups with p<0.05 (ANOVA-Bonferroni). Conclusions: sevoflurane was more effective than Isoflurane in protecting against ischemia reperfusion injury. Ischemic preconditioning prove to be more protective than both halogenated anesthetics.

[Behavior of intraocular pressure according to cardiorespiratory and hemodynamic effects induced by desflurane in dogs subjected to experimental hypovolemia]. / Comportamento da pressão intra-ocular segundo os efeitos cardiorrespiratórios e hemodinâmicos induzidos pela anestesia com desflurano, em cães submetidos à hipovolemia experimental.

PURPOSE: To observe the behavior of intraocular pressure according to the cardiopulmonary and hemodynamic effects induced by desflurane in dogs subjected to experimental hypovolemia. METHODS: Eighteen healthy male and female mongrel dogs, weighing between 10 and 15 kg were used. Hypovolemia was induced by withdrawal of 40 ml blood/kg body weight. Then anesthesia was induced with desflurane by mask until tracheal intubation was permitted. Intraocular pressure was measured with applanation tonometry. Heart rate, cardiac output, mean arterial pressure, central venous pressure, end-tidal concentration of CO2 and respiratory rate were recorded. Parameters were registered after animal instrumentation and before any procedure in the awake dogs (T0), fifteen minutes after experimental hemorrhage induction (T45), and after thirty minutes of desflurane anesthesia (T75). RESULTS: Intraocular pressure presented direct correlation only with pressure and end-tidal concentration of CO2. CONCLUSIONS: It was not possible to establish a correlation between alterations of mean arterial pressure and central venous pressure and intraocular pressure and there was a direct relationship between values of intraocular pressure and values of exhaled CO2.

Comportamento da pressão intra-ocular segundo os efeitos cardiorrespiratórios e hemodinâmicos induzidos pela anestesia com desflurano, em cães submetidos à hipovolemia experimental / Behavior of intraocular pressure according to cardiorespiratory and hemodynamic effects induced by desflurane in dogs subjected to experimental hypovolemia

OBJETIVOS: Observar o comportamento da pressão intra-ocular, segundo os efeitos cardiorrespiratórios e hemodinâmicos induzidos pela anestesia geral com desflurano, em cães submetidos à hipovolemia experimental. MÉTODOS: Foram utilizados 18 cães, machos e fêmeas, com peso entre 10 e 15 kg. A hipovolemia foi realizada retirando-se 40 ml de sangue/kg de peso. A seguir, a anestesia foi induzida com desflurano através de máscara facial, até que a intubação orotraqueal fosse permitida. A pressão intra-ocular foi medida por tonometria de aplanação. Valores para freqüência cardíaca, débito cardíaco, pressão arterial média, pressão venosa central e pressão parcial de CO2 ao final da expiração e freqüência respiratória foram mensurados. Os parâmetros da avaliação foram registrados após a instrumentalização e antes de qualquer outro procedimento (T0), quinze minutos depois da indução da hipovolemia experimental (T45) e após 30 minutos da indução anestésica (T75). RESULTADOS: A pressão intra-ocular apresentou relação direta somente com a pressão parcial de CO2 no final da expiração. CONCLUSÕES: Não foi possível estabelecer correlação entre alterações da pressão arterial média e da pressão venosa central com a pressão intra-ocular e houve relação direta entre os valores da pressão intra-ocular e os de ETCO2.