Intraocular pressure and pupil diameter in healthy cats anesthetized with isoflurane and pre-medicated with isolated acepromazine or in combination with tramadol / [Pressão intraocular e diâmetro pupilar em gatos saudáveis anestesiados com isoflurano e pré-medicados com acepromazina isolada ou em combinação com tramadol]

The objective of this study was to determine changes on intraocular pressure (IOP) and pupil diameter (PD) in healthy cats anesthetized with isoflurane, and premedicated with acepromazine alone or in combination with tramadol. Thirty cats were allocated in two groups (n=15/each) and were treated with acepromazine (AG) or acepromazine/tramadol (ATG). PD and IOP were assessed before and following 30 (PM1), and 40 minutes (PM2) of treatments. Anesthesia was induced with propofol, and IOP and DP were recorded (A10) at 10 minute intervals until the end of anesthesia (A40). IOP decreased in AG and ATG, when comparing baseline with PM1. IOP decreased only in AG, in comparisons between baseline and PM2. During anesthesia, IOP did not change within and between groups. Comparisons between baseline with those recorded at PM1 and 2 showed that PD increased in the ATG. During anesthesia, PD decreased significantly in AG and ATG. Both protocols maintained the IOP within the reference range to perform corneal or intraocular surgery in healthy cats but did not sustain pre-anesthetic pupil dilation observed in ATG.(AU)

O objetivo do presente artigo é determinar possíveis alterações na pressão intraocular (PIO) e no diâmetro pupilar (DP) em gatos saudáveis anestesiados com isoflurano e pré-medicados com acepromazina isolada ou em combinação com acepromazina/tramadol. Trinta gatos saudáveis foram distribuídos aleatoriamente em dois grupos (n=15/cada) e tratados com acepromazina (GA) ou acepromazina/tramadol (GAT). DP e PIO foram avaliadas antes (basal) e após 30 (PM1) e 40 minutos (PM2) dos tratamentos. A anestesia foi induzida com propofol, e a PIO e o DP foram registrados (A10) a cada 10 minutos até o final da anestesia com isoflurano (A40). Ao se compararem os valores obtidos no basal com PM1, a PIO diminuiu em GA e GAT; com PM2, a PIO reduziu apenas no GA. Durante a anestesia, a PIO não diferiu dentro e entre os grupos. Comparações entre os valores basais e os registrados em PM1 e em PM2 mostraram que a DP aumentou significativamente no GAT. Durante a anestesia, o DP diminuiu significativamente em GA e GAT. Ambos os protocolos mantêm a PIO dentro dos valores de referência para realizar cirurgias corneanas ou intraoculares em gatos saudáveis, mas não sustentam a dilatação pupilar pré-anestésica observada em GAT.(AU)

Effects of huperzine A on hippocampal inflammatory response and neurotrophic factors in aged rats after anesthesia

Abstract Purpose To investigate the effects of huperzine A (HupA) on hippocampal inflammatory response and neurotrophic factors in aged rats after anesthesia. Methods Thirty-six Sprague Dawley rats (20-22 months old) were randomly divided into control, isofluran, and isoflurane+HupA groups; 12 rats in each group. The isoflurane+HupA group was intraperitoneally injected with 0.2 mg/kg of HupA. After 30 min, isoflurane inhalation anesthesia was performed in the isoflurane and isoflurane+HupA groups. After 24 h from anesthesia, Morris water maze experiment and open-field test were performed. Hippocampal inflammatory and neurotrophic factors were determined. Results Compared with isoflurane group, in isofluran+HupA group the escape latency of rats was significantly decreased (P < 0.05), the original platform quadrant residence time and traversing times were significantly increased (P < 0.05), the central area residence time was significantly increased (P < 0.05), the hippocampal tumor necrosis factor α, interleukin 6 and interleukin 1β levels were significantly decreased (P < 0.05), and the hippocampal nerve growth factor, brain derived neurotrophic factor and neurotrophin-3 levels were significantly increased (P < 0.05). Conclusion HupA may alleviate the cognitive impairment in rats after isoflurane anesthesia by decreasing inflammatory factors and increasing hippocampal neurotrophic factors in hippocampus tissue.

Fulminant hepatic failure after simultaneous kidney-pancreas transplantation: a case report / Insuficiência hepática fulminante após transplante simultâneo de rim-pâncreas: um relato de caso

Abstract We describe an unusual case of hyperacute hepatic failure following general anesthesia in a patient receiving a simultaneous kidney-pancreas transplant. Despite an aggressive evaluation of structural, immunological, viral, and toxicological causes, a definitive cause could not be elucidated. The patient required a liver transplant and suffered a protracted hospital course. We discuss the potential causes of fulminant hepatic failure and the perioperative anesthesia management of her subsequent liver transplantation.

Resumo Descrevemos um caso incomum de insuficiência hepática hiperaguda após a anestesia geral em uma paciente que recebeu um transplante simultâneo de rim-pâncreas. Apesar de uma avaliação agressiva das causas estruturais, imunológicas, virais e toxicológicas, uma causa definitiva não pôde ser identificada. A paciente precisou de um transplante de fígado que resultou em prolongamento da internação hospitalar. Discutimos as potenciais causas da insuficiência hepática fulminante e o manejo da anestesia no período perioperatório de seu subsequente transplante de fígado.

Hipertermia maligna: a propósito de un caso / Malignant hyperthermia: a case report

Malignant hyperthermia (MH) is a rare neuromuscular hereditary disorder, triggered in susceptible individuals by exposure to inhalational agents or succinylcholine and manifested as a hypermetabolic state. We report the case of a 22 years old male patient anesthetized with Desflurane in whom MH was suspected because of unexplained increased levels of End-Tidal carbon dioxide. Dantrolene was administered with good response. Respiratory acidosis and hyperkalemia were also detected but could be easily controlled. The postoperative period was uneventful with the exception of a superficial venous thrombosis at the dantrolene’s injection site. The patient was discharged eight days after the episode without sequela. Successful management of a malignant hyperthemia episode must include: early suspicion, asking for help and early treatment with dantrolene.

La Hipertermia Maligna es un trastorno neuromuscular hereditario infrecuente, manifestado por un estado hipermetabólico desencadenado en individuos susceptibles por la exposición a anestésicos halogenados o Succinilcolina. Se reporta el caso de un hombre de 22 años anestesiado con Desflurano, en quien el diagnóstico de Hipertermia Maligna se sospechó por la presencia de elevación inexplicada del CO2 espirado, que respondió a la suspensión del Desflurano y administración de Dantroleno. Se observó además hiperkalemia y acidosis respiratoria, que fueron fácilmente compensadas. La evolución postoperatoria fue satisfactoria, a excepción de una trombosis venosa superficial en el sitio de inyección del Dantroleno. El paciente fue dado de alta al 8avo día postoperatorio, sin secuelas. Las claves del manejo exitoso de un episodio de hipertermia maligna están en: Sospecha precoz, solicitar ayuda e inició rápido del tratamiento con Dantroleno.

Conservative treatment of Angle Class III malocclusion with anterior crossbite

Angle Class III malocclusion is characterized by anteroposterior dental discrepancy which might be associated or not with skeletal changes. Class III molar relationship is associated with vertical or lingually tipped mandibular incisors and a usually concave profile. These characteristics seriously affect facial esthetics and most frequently are the reason why patients seek orthodontic treatment. This case was presented to the committee of the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) as part of the requisites to become a BBO Diplomate.

A má oclusão de Classe III de Angle é caracterizada por uma discrepância dentária anteroposterior, que pode ou não estar acompanhada por alterações esqueléticas. Observa-se uma relação molar de Classe III associada ao posicionamento vertical ou retroinclinado dos incisivos inferiores e, geralmente, perfil facial côncavo. Esse aspecto gera grande comprometimento estético na face, sendo justamente esse o fator que, na maioria das vezes, motiva o paciente a procurar pelo tratamento ortodôntico. O presente caso clínico foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO) como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

Determinação da concentração alveolar mínima do isofluorano em catetos (Tayassu tajacu) / Isoflurane minimum alveolar concentration in collared peccary (Tayassu tajacu)

A anestesia inalatória vem sendo amplamente difundida na medicina veterinária, no entanto seu uso em animais selvagens ainda é restrito, não sendo observado nenhum estudo referente à sua utilização na espécie Tayassu tajacu. O objetivo da pesquisa foi determinar a concentração alveolar mínima (CAM) do isofluorano em catetos e apresentar os efeitos desta administração sobre as variáveis hemodinâmicas e respiratórias, como também a qualidade da recuperação anestésica. Utilizou-se 10 animais, machos, com idade variando de 1 a 3 anos oriundos do Centro de Multiplicação de Animais Silvestres da Universidade Federal Rural do Semi-Árido, Brasil. Todos os animais tiveram anestesia induzida com 7mg.kg-1 de propofol e posteriormente foram conectados a circuito anestésico com isofluorano e oxigênio 100 por cento. O estímulo noceptivo supramáximo adotado foi pinçamento interdigital, o qual era realizado após 15 minutos de espera para cada concentração de isofluorano fornecida. Ao ser observada resposta negativa frente ao estímulo a concentração era reduzida em 20 por cento, quando verificada resposta positiva o estímulo era cessado, calculando-se a partir daí o valor da CAM. [...] A recuperação anestésica foi tranquila e rápida. Concluiu-se que a CAM do isofluorano para catetos foi maior que a observada em espécies afins. O isofluorano pode ser utilizado nesta espécie, sendo considerado seguro e eficaz. A recuperação dos animais após anestesia com isofluorano foi livre de excitação.

Inhalation anesthesia has been widespread in veterinary medicine. Nevertheless, its use in wild animals is still limited, having no studies on its use been observed in the species. The objective of the research was to determine the isoflurane minimum alveolar concentration (MAC) in peccaries and present the effects of its administration on the hemodynamic and respiratory variables, as well as data concerning the anesthesia recovery. The study used 10 male animals with age ranging from one to three years, from the Centro de Multiplicação de Animais Silvestres of Universidade Federal Rural do Semi-Árido, Brazil. All the animals had anesthesia induced with propofol 7mg.kg-¹, were intubated and connected to the anesthetic circuit with isoflurane and 100 percent oxygen. The supramaximal noxious stimulation used was the interdigital pinch, which was performed after 15 minutes of waiting for each provided isoflurane concentration. When negative response to the stimulus was observed, the concentration was reduced by 20 percent; when positive response was verified, the stimulus was stopped, being the CAM value calculated from that point. [...] Recovery was quiet and smooth. It was concluded that the isoflurane MAC for peccaries was greater than that observed in related species. Isoflurane can be used in this species, being considered safe and effective. The animals' recovery after anesthesia with isoflurane was free from excitement.

Incidence and Risk Factors of Postoperative Nausea and Vomiting in Patients with Fentanyl-Based Intravenous Patient-Controlled Analgesia and Single Antiemetic Prophylaxis

PURPOSE: We evaluated the incidence and risk factors of postoperative nausea and vomiting (PONV) in patients with fentanyl-based intravenous patient-controlled analgesia (IV-PCA) and single antiemetic prophylaxis of 5-hydroxytryptamine type 3 (5 HT3)-receptor antagonist after the general anesthesia. MATERIALS AND METHODS: In this retrospective study, incidence and risk factors for PONV were evaluated with fentanyl IV-PCA during postoperative 48 hours after various surgeries. RESULTS: Four hundred-forty patients (23%) of 1878 had showed PONV. PCA was discontinued temporarily in 268 patients (14%), mostly due to PONV (88% of 268 patients). In multivariate analysis, female, non-smoker, history of motion sickness or PONV, long duration of anesthesia (>180 min), use of desflurane and intraoperative remifentanil infusion were independent risk factors for PONV. If one, two, three, four, five, or six of these risk factors were present, the incidences of PONV were 18%, 19%, 22%, 31%, 42%, or 50%. Laparoscopic surgery and higher dose of fentanyl were not risk factors for PONV. CONCLUSION: Despite antiemetic prophylaxis with 5 HT3-receptor antagonist, 23% of patients with fentanyl-based IV-PCA after general anesthesia showed PONV. Long duration of anesthesia and use of desflurane were identified as risk factors, in addition to risk factors of Apfel's score (female, non-smoker, history of motion sickness or PONV). Also, intraoperative remifentanil infusion was risk factor independent of postoperative opioid use. As the incidence of PONV was up to 50% according to the number of risk factors, risk-adapted, multimodal or combination therapy should be applied.

Comparison of Emergence Time in Children Undergoing Minor Surgery According to Anesthetic: Desflurane and Sevoflurane

PURPOSE: In earlier analyses, desflurane has been shown to reduce average extubation time and the variability of extubation time by 20% to 25% relative to sevoflurane in adult patients. We undertook this study to determine which agents prompt less recovery time in pediatric patients undergoing minor surgery. MATERIALS AND METHODS: After obtaining Institutional Review Board approval, we retrospectively reviewed the anesthesia records of 499 patients, with an average age of 5 years, who underwent minor surgeries at Severance Eye and Ear, Nose and Throat Hospital between May 2010 and April 2011. Anesthesia was induced with propofol and rocuronium. Anesthesia was maintained with sevoflurane (n=340) or desflurane (n=159) with 50% air/O2. Time from cessation of anesthetics to recovery of self-respiration, eye opening on verbal command and extubation were compared between the two groups. Additionally, the incidences of postoperative respiratory adverse events were also compared. RESULTS: Times to self-respiration recovery, eye opening on verbal command, and extubation were significantly faster in the desflurane group than the sevoflurane group (4.6+/-2.5 min vs. 6.9+/-3.8 min, 6.6+/-3.0 min vs. 9.2+/-3.6 min, and 6.2+/-2.7 min vs. 9.3+/-3.7 min, respectively, p<0.005). There were no statistically significant differences between the two groups with respect to adverse respiratory events during the peri-operative period (38.2% vs. 34.6%, p=0.468). CONCLUSION: Emergence and recovery from anesthesia were significantly faster in the desflurane group of children undergoing minor surgery. Desflurane did not result in any differences in respiratory adverse events during recovery compared to sevoflurane.

Effect-Site Concentration of Remifentanil for Minimizing Cardiovascular Changes by Inhalation of Desflurane

PURPOSE: This study aims to investigate the most appropriate effect-site concentration of remifentanil to minimize cardiovascular changes during inhalation of high concentration desflurane. MATERIALS AND METHODS: Sixty-nine American Society of Anesthesiologists physical status class I patients aged 20-65 years were randomly allocated into one of three groups. Anesthesia was induced with etomidate and rocuronium. Remifentanil was infused at effect-site concentrations of 2, 4 and 6 ng/mL in groups R2, R4 and R6, respectively. After target concentrations of remifentanil were reached, desflurane was inhaled to maintain the end-tidal concentration of 1.7 minimum alveolar concentrations for 5 minutes (over-pressure paradigm). The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and end-tidal concentration of desflurane were measured for 5 minutes. RESULTS: The end-tidal concentration of desflurane increased similarly in all groups. The SBP, DBP, MAP and HR within group R4 were not significantly different as compared with baseline values. However, measured parameters within group R2 increased significantly 1-3 minutes after desflurane inhalation. The MAP within group R6 decreased significantly at 1, 2, 4, and 5 minutes (p<0.05). There were significant differences in SBP, DBP, MAP and HR among the three groups 1-3 minutes after inhalation (p<0.05). The incidence of side effects such as hyper- or hypo-tension, and tachy- or brady-cardia in group R4 was 4.8% compared with 21.8% in group R2 and 15.0% in group R6. CONCLUSION: The most appropriate effect-site concentration of remifentanil for blunting hemodynamic responses by inhalation of high concentration desflurane is 4 ng/mL.

Kidney Function in Living Donors Undergoing Nephrectomy by Sevoflurane or Desflurane Anesthesia

PURPOSE: Although there is no clinical evidence of nephrotoxicity with the volatile anesthetics currently used in general anesthesia, a better agent should be needed in terms of preserving postoperative renal function in living kidney donors who have only single remaining kidney. The purpose of the current retrospective, single-center study was to evaluate and compare renal function of living kidney donors after nephrectomy under either sevoflurane or desflurane anesthesia. MATERIALS AND METHODS: From January 2006 through December 2011, a total of 228 donors undergoing video assisted minilaparotomy surgery nephrectomy for kidney donation were retrospectively enrolled in the current study. The donors were categorized into a sevoflurane group or desflurane group based on the type of volatile anesthetic used. We collected laboratory data from the patients preoperatively, immediately after the operation, on the first postoperative day and on the third postoperative day. We also compared renal function of the kidney donors after donor nephrectomy by comparing creatinine level and estimated glomerular filtration rate (eGFR). RESULTS: The decrease in renal function after surgery in both groups was the most prominent on the first postoperative day. There were no significant differences between the two groups in postoperative changes of creatinine or eGFR. CONCLUSION: Sevoflurane and desflurane can be used safely as volatile anesthetics in donors undergoing nephrectomy.

Sevoflurane causes less arrhythmias than desflurane after off-pump coronary artery bypass grafting: A pilot study.

Background: Volatile anesthetics provide myocardial protection during cardiac surgery. Sevoflurane and desflurane are both efficient agents that allow immediate extubation after off-pump coronary artery bypass grafting (OPCABG). This study compared the incidence of arrhythmias after OPCABG with the two agents. Materials and Methods: Forty patients undergoing OPCABG with immediate extubation and perioperative high thoracic analgesia were included in this controlled, double-blind study; anesthesia was either provided using 1 MAC of sevoflurane (SEVO-group) or desflurane (DES-group). Monitoring of perioperative arrhythmias was provided by continuous monitoring of the EKG up to 72 hours after surgery, and routine EKG monitoring once every day, until time of discharge. Patient data, perioperative arrhythmias, and myocardial protection (troponin I, CK, CK-MB-ratio, and transesophageal echocardiography examinations) were compared using t-test, Fisher's exact test or two-way analysis of variance for repeated measurements; P < 0.05. Results: Patient data and surgery-related data were similar between the two groups; all the patients were successfully extubated immediately after surgery, with similar emergence times. Supraventricular tachycardia occurred only in the DES-group (5 of 20 patients), atrial fibrillation was significantly more frequent in the DES group versus SEVO-group, at five out of 20 versus one out of 20 patients, respectively. Myocardial protection was equally achieved in both groups. Discussion: Ultra-fast track anesthesia using sevoflurane seems more advantageous than desflurane for anesthesia, for OPCABG, as it is associated with significantly less atrial fibrillation or supraventricular arrhythmias after surgery.

Ocorrência da agitação no despertar em crianças anestesiadas com isoflurano ou sevoflurano: influência do tratamento com a dexmedetomidina / Agitation at awakening in children anesthetized with isoflurane or sevoflurane: influence of treatment with dexmedetomidine

A agitação ao despertar tem sido descrita como um fenômeno comum em crianças anestesiadas com agentes inalatórios. Apesar do sevoflurano e do desflurano serem os agentes mais comumente associados a essa complicação, ainda não está claro se a incidência da agitação é menor com o emprego do isoflurano. Diferentes agentes têm sido empregados para reduzir a probabilidade de ocorrência da agitação ao despertar. A dexmedetomidina, um agente α2-agonista altamente seletivo, parece reduzir a incidência dessa complicação após anestesia com sevoflurano ou desflurano. No entanto, ainda não se avaliou os efeitos da administração desse agente em crianças submetidas à anestesia com isoflurano. O presente estudo teve como objetivo testar a hipótese de que a incidência de agitação ao despertar é maior em crianças anestesiadas com o sevoflurano quando comparada àquela observada após a anestesia com o isoflurano, segundo a aplicação de uma escala validada e com confiabilidade comprovada (Pediatric Anesthesia Emergence Delirium - PAED) aplicada na sala de recuperação pósanestésica (SRPA). Também foi avaliada a hipótese de que a administração da dexmedetomidina antes do fim da anestesia reduz a incidência dessa complicação. Realizou-se ensaio clínico, comparativo, randomizado, duplo cego e controlado. Foram estudadas 140 crianças, com idade entre 2 e 12 anos, submetidas à amigdalectomia, associada ou não à adenoidectomia, sob anestesia geral. As crianças foram distribuídas, de forma aleatória, em quatro grupos de estudo de acordo com o anestésico inalatório empregado para a manutenção da anestesia e pela administração ou não da dexmedetomidina no final da cirurgia: Grupo S (n=35) – Sevoflurano e solução fisiológica; Grupo SD (n=35) – Sevoflurano e dexmedetomidina 0,5 μg.kg-1; Grupo I (n=35) Isovoflurano e solução fisiológica; Grupo ID (n=35) - Isovoflurano e dexmedetomidina 5 miug.kg-1...

A comparison of the effects of desflurane, sevoflurane and propofol on QT, QTc, and P dispersion on ECG.

The aim of this prospective, randomized, and double-blinded study was to compare the effects of desflurane, sevoflurane, propofol on both atrial and ventricular wall function by measurement of QT dispersion (QTd), corrected QT dispersion (QTcd), and P dispersion (Pd) on electrocardiogram (ECG). Forty-six patients from the American Society of Anesthesiologists class I−II undergoing noncardiac surgery, were enrolled in this study. Patients were randomly allocated to receive desflurane, sevoflurane or propofol anesthesia. ECG recordings were taken before and after 5 minutes of drug administration. Induction with desflurane significantly increased the QTd compared to baseline (38 ± 2 ms vs. 62 ± 6 ms, P < 0.05). Sevoflurane and propofol anesthesia was not associated with any changes in QTd. QTcd was increased with desflurane induction and decreased with sevoflurane and propofol induction, but this decrease was only significant in the propofol group (67 ± 5 ms vs. 45 ± 3 ms, P < 0.05). Pd was significantly increased after induction with desflurane (34 ± 3 vs. 63 ± 6 ms, P < 0.05). There was a significant increase in QTd and Pd in desflurane group, but this increment did not cause any dangerous arrhythmias. QTcd significantly decreased in propofol group. We believe that further investigations are required for using desflurane as safe as sevoflurane and propofol in noncardiac surgery patients who have high cardiac arrhythmia and ischemia risk.

Instabilidade hemodinâmica grave durante o uso de isoflurano em paciente portador de escoliose idiopática: relato de caso / Severe hemodynamic instability during the use of isoflurane in a patient with idiopathic scoliosis: case reportInestabilidad hemodinámica grave durante el uso de isoflurano en paciente portador de escoliosis idiopática: relato de caso

JUSTIFICATIVA E OBJETIVOS: O isoflurano é considerado um anestésico inalatório seguro. Apresenta reduzido grau de biotransformação, baixa toxicidade hepática e renal. Em concentrações clínicas apresenta efeito inotrópico negativo mínimo, diminuição da resistência vascular sistêmica e, raramente, pode provocar disritmias cardíacas. O objetivo deste relato foi apresentar um caso de instabilidade hemodinâmica grave em paciente portador de escoliose idiopática. RELATO DO CASO: Paciente do sexo masculino, 13 anos, estado físico ASA I, sem antecedente de alergia a medicamentos, agendado para correção cirúrgica de escoliose idiopática. Após indução da anestesia com fentanil, midazolam, propofol e atracúrio, isoflurano a 1 por cento, em 100 por cento de oxigênio foi então iniciado para manutenção. Cinco minutos depois, o paciente apresentou hipotensão arterial grave (PAM = 26 mmHg) associada à taquicardia sinusal (FC = 166 bpm) que não respondeu ao uso de vasopressores e infusão de volume. A ausculta pulmonar e precordial, oximetria, capnografia, temperatura nasofaríngea e gasometria arterial revelaram-se sem alterações. O paciente recebeu tratamento para anafilaxia e a intervenção cirúrgica foi interrompida. A clara relação temporal entre a administração de isoflurano e a ocorrência dos sintomas sugeriu um diagnóstico de intolerância cardiovascular à administração inalatória de isoflurano. Duas semanas depois a anestesia venosa total foi administrada sem intercorrências. CONCLUSÕES: Não há relatos de instabilidade hemodinâmica grave causada por isoflurano em pacientes previamente sadios. Anafilaxia, taquicardia supraventricular com repercussão hemodinâmica e sensibilidade cardíaca aumentada ao isoflurano são discutidas como possíveis causas da instabilidade hemodinâmica. Atualmente, há evidências que o isoflurano pode interferir no sistema de acoplamento-desacoplamento da contratilidade miocárdica por meio da redução do Ca2+ citosólico e/ou...

BACKGROUND AND OBJECTIVES: Isoflurane is considered a safe inhalational anesthetic. It has a low level of biotransformation, and low hepatic and renal toxicity. In clinical concentrations, it has minimal negative inotropic effect, causes a small reduction in systemic vascular resistance, and, rarely, can cause cardiac arrhythmias. The objective of this report was to present a case of severe hemodynamic instability in a patient with idiopathic scoliosis. CASE REPORT: Male patient, 13 years old, ASA physical status I, with no prior history of allergy to medications, scheduled for surgical repair of idiopathic scoliosis. After anesthetic induction with fentanyl, midazolam, propofol, and atracurium, 1 percent isoflurane with 100 percent oxygen was initiated for anesthesia maintenance. After five minutes, the patient presented severe hypotension (MAP = 26 mmHg) associated with sinus tachycardia (HR = 166 bpm) that did not respond to the administration of vasopressors and fluids. Lung and heart auscultation, pulse oxymetry, capnography, nasopharyngeal temperature, and arterial blood gases did not change. The patient was treated for anaphylaxis and the surgery was cancelled. The clear temporal relationship between the administration of isoflurane and the symptoms suggested the diagnosis of cardiovascular intolerance to inhalational isoflurane. Two weeks later, total intravenous anesthesia was administered without complications. CONCLUSIONS: There are no reports of severe hemodynamic instability caused by isoflurane in previously healthy individuals. Anaphylaxis, supraventricular tachycardia with hemodynamic consequences, and increased cardiac sensitivity to isoflurane are discussed as possible causes of the hemodynamic instability. Currently, there is evidence that isoflurane can interfere in the coupling-uncoupling system of myocardial contractility by reducing cytosolic Ca2+ and/or depressing the function of contractile proteins. The fundamental...

JUSTIFICATIVA Y OBJETIVOS: El isoflurano se considera un anestésico de inhalación seguro. Presenta un reducido grado de biotransformación, baja toxicidad hepática y renal. En concentraciones clínicas presenta efecto inotrópico negativo mínimo, disminución de la resistencia vascular sistémica y raramente puede provocar arritmias cardíacas. El objetivo de este relato fue presentar un caso de inestabilidad hemodinámica grave en paciente portador de escoliosis idiopática. RELATO DE CASO: Paciente del sexo masculino, 13 años, estado físico ASA I, sin antecedente de alergia a medicamentos, con consulta marcada para corrección quirúrgica de escoliosis idiopática. Después de la inducción de la anestesia con fentanil, midazolam, propofol y atracurio, isoflurano a 1 por ciento, en 100 por ciento de oxígeno se inició el mantenimiento. Cinco minutos después el paciente presentó hipotensión arterial grave (PAM = 26 mmHg) asociada a la taquicardia sinusal (FC = 166 bpm) que no respondió al uso de vasopresores e infusión de volumen. La ausculta pulmonar y precordial, oximetría, capnografía, temperatura nasofaríngea y gasometría arterial no tuvieron alteraciones. El paciente recibió tratamiento para anafilaxia y la intervención quirúrgica fue interrumpida. La clara relación temporal entre la administración de isoflurano y la incidencia de los síntomas sugirió un diagnóstico de intolerancia cardiovascular a la administración de inhalación de isoflurano. Dos semanas después, la anestesia venosa total se administró sin problemas. CONCLUSIONES: No existen relatos de inestabilidad hemodinámica grave causada por isoflurano en pacientes previamente saludables. Anafilaxia, taquicardia supraventricular con repercusión hemodinámica y sensibilidad cardiaca aumentada al isoflurano son discutidas como posibles causas de la inestabilidad hemodinámica. Actualmente, existen evidencias de que el isoflurano pude interferir en el sistema de acoplamiento y desacoplamiento...

Estudo com anestesia com remifentanil e isoflurano em cães: efeito redutor sobre a concentração alveolar mínima (CAM) e avaliação hemodinâmica / An investigation on the anesthesia with remifentanil and isoflurane in dogs: isoflurane-sparing effect of remifentanil on the minimum alveolar concentration (MAC) and hemodynamic changes

O efeito do remifentanil sobre a concentração alveolar mínima do isoflurano (CAMISO) foi estudado em seis cães com peso médio de 27,7 mais ou menos 4,3 kg. Os animais foram anestesiados com isoflurano sob ventilação mecânica, mantendo-se normocapnia (PaCO2 média: 38,5 mm Hg) e normotermia (temperatura corpórea média: 38,1ºC). A CAMISO, determinada por meio da estimulação nociceptiva (50V/50Hz/10ms) do membro torácico, foi mensurada antes (basal), durante a infusão contínua de diferentes doses de remifentanil (0,15; 0,30; 0,60 e 0,90 micrograma/kg/min) e aproximadamente 80 minutos após o término da infusão do opióide. Após um intervalo de 7 dias, a CAMISO foi determinada às 2, 4 e 6 horas após o início da infusão de 0,15 micrograma/kg/min de remifentanil. As variáveis foram analisadas por meio de ANOVA seguida pelo teste de Tukey ou Dunnett (P menor que 0,05). A CAMISO redeterminada ao término da infusão (1,22 mais ou menos 0,20%) não diferiu da CAMISO basal (1,38 mais ou menos 0,20%). Os valores da CAMISO foram significativamente mais baixos nas três maiores taxas de infusão em relação à menor (0,15 micrograma/kg/min). Observou-se redução significativa da CAMISO com todas as taxas de infusão de remifentanil (reduções percentuais em relação ao valor basal de 43 mais ou menos 10%, 59 mais ou menos 10%, 66 mais ou menos 9% e 71 mais ou menos 9% para as taxas de 0,15; 0,30; 0,60 e 0,90 micrograma/kg/min, respectivamente). Embora o valor da CAMISO não tenha diferido entre as taxas de infusão de 0,30; 0,60 e 0,90 micrograma/kg/min, apercentagem de redução na CAMISO foi maior com a dose de 0,90 em relação à dose de 0,30 micrograma/kg/min. A CAMISO não se modificou ao longo do tempo com a taxa de 0,15 micrograma/kg/min. Em uma segunda etapa de experimentos, os efeitos hemodinâmicos da anestesia comremifentanil e isoflurano foram estudados nos mesmos cães...

Effects of sevoflurane and isoflurane on coagulation system a comparative study

Several studies of the effects of inhalational anesthetic agents on platelet function have been reported since Ueda demonstrated in 1971 that clinical concentrations of halothane inhibited ADP-induced platelet aggregation. Sevoflurane in particular has recently been the subject of several investigations; however, the results remain contradictory. Platelets play an important role in hemostasis during and after surgery. Among multiple factors, interactions of drugs used in anesthesia with platelet function have been implicated to aggravate the risk of perioperative bleeding. In this study, the aim was to assess the effects of sevoflurane and isoflurane on the coagulation system. Patients were randomly divided into two groups [30 patients each]: isoflurane group [group I] and sevoflurane group [group S] according to the inhalational anesthetic used for maintenance of anesthesia. Blood samples were withdrawn before induction, 1 hour after induction and 1 hour postoperatively to measure red blood cells count, hemoglobin level, platelets count, bleeding time, prothrombin time and activity, activated partial thromboplastin time, pH, body temperature and platelet aggregation tests. The results of this study showed that red blood cells count, hemoglobin level, blood pH values and vital signs measurements were insignificantly changed during the predetermined times of measurements. Sevoflurane had a significant inhibitory effect on intraoperative platelet aggregation. Also, it had a residual suppressive effect 1 hour postoperatively, whereas it had no significant effect on other coagulation parameters including platelet count, bleeding time, prothrombin time and activity and activated partial thromboplastin time. As regards isoflurane, it had no significant effect neither on platelet aggregation nor other coagulation parameters during the intraoperative and postoperative periods. The conclusion of this study is that sevoflurane has a significant inhibitory effect on intraoperative platelet aggregation, whereas isoflurane has no effect. There is also a residual suppressive effect 1 hour postoperatively with sevoflurane. Therefore, in patients at increased risk of intraoperative and postoperative bleeding, isoflurane may be preferred as an inhalational agent for maintenance of general anesthesia.

Fatal isoflurane hepatotoxicity without re-exposure.

Isoflurane is less hepatotoxic than its predecessors, halothane and enflurane. We present a 68-year-old man who developed fulminant and fatal hepatic necrosis two days after open cholecystectomy done under isoflurane anesthesia. Laboratory findings included grossly elevated transaminases and bilirubin and prolonged prothrombin time. Serological studies were negative for viral hepatitis. Postmortem examination demonstrated centrilobular necrosis of liver.

effect of halothane, isoflurane, sevoflurane and propofol infusion on renal function after coronary artery bypass surgery

Renal insufficiency after cardiac surgery is associated with increased mortality, morbidity, and length of stay in the intensive care unit. We investigated the effect of isoflurane, halothane, sevoflurane and propofol anesthesia on perioperative renal function following elective coronary artery surgery. The medical records of 224 patients, in the Hacettepe University Medical Faculty Hospital who had undergone cardiac surgery in one year, were retrospectively reviewed. 65 [29%] patients received isoflurane, 68 [30%] patients received halothane, 64 [29%] patients received sevoflurane, and 27 [12%] patients received propofol infusion as part of maintenance anesthesia for coronary artery bypass surgery. Patient characteristics [age, sex, preoperative ejection fraction], operative data [duration of CPB, duration of operation, number of distal anastomoses, usage of diuretic, intraoperative crystalloid and blood transfusion], intraoperative urinary output, preoperative and postoperative [6th hours and 24th hours] BUN and plasma creatinine levels, were not statistically significant between and within groups. Intraoperative inotropic agent [dopamine] was used in 8 [12.3%] patients in the isoflurane group, in 10 [14.7%] patients in the halothane group, in 11 [17.2%] patients in sevoflurane group and in 9 [33.3%] patients in the propofol group. Postoperatively fluid and blood transfusion, postoperative drainage, urinary output, diuretic usage were smiliar between the four groups [p>0,05]. Inotropic agent was used in 8 [12.3%] patients in the isoflurane group, in 9 [13.2%] patients in the halothane group, in 16 [25%] patients in the sevoflurane group and in 7 [25.9%] patients in the propofol group. It is concluded that, halothane, isoflurane, sevoflurane and propofol infusion anesthesia as part of anesthesia maintenance for elective coronary artery bypass surgery does not affect early postoperative renal functions