Avaliaçäo comparativa entre a anestesia geral com halotano e isoflurano sobre a pressäo arterial em cäes / Comparartive evaluation of the general anesthesia with halothane and isoflurane on the arterial pressure in dogs

As alteraçöes produzidas pelo halotano e isoflurano sobre as pressöes arteriais sistólica, diastólica e média foram avaliadas em 34 caninos de ambos os sexos e de diferentes pesos corporais e raças, todos submetidos a procedimentos cirúrgicos ortopédicos, divididos em dois grupos de 17 animais, submetidos a jejum prévio de 12 horas antes da induçäo anestésica. Os animais de ambos os grupos receberam sulfato de atropina 0,04mg/kg, associado ao sulfato de morfina 1,5mg/kg, administrados por via intramuscular e induçäo anestésica com propofol 6mg/kg por via intravenosa e a anestesia geral foi mantida com halotano no grupo I e o isoflurano no grupo II. Em ambos os grupos, o óxido nitroso na proporçäo 2:1 com oxigênio foi utilizado como gás diluente do anestésico volátil. Decorridos 15 minutos do início da anestesia volátil, as pressöes sistólica, diastólica e média foram mensuradas pelo método oscilométrico indireto até o período de 90 minutos. Observou-se que as pressöes arteriais sistólica e diastólica do grupo II foi maior a partir dos 45 minutos de manutençäo com os anestésicos voláteis, näo ocorrendo diferença significativa na freqüência cardíaca. Conclui-se que a manutençäo anestésica com isoflurano produz valores de pressäo arterial sistólica e diastólica superiores à manutençäo com halotano que causou hipotensäo arterial dos 45 aos 75 minutos de anestesia volátil.

Hepatitis tóxica por halotano / Toxic hepatitis because of halothane

Se comunica el caso de una paciente de 43 años que presentó astenia, adinamia, náusea, escalofríos y ataque al estado general de cuatro días de evolución ocho días después de una segunda exposición al halotano que le provocó una hepatitis tóxica y la muerte. El halotano es un agente anestésico semejante al cloroformo que puede producir lesión hepática

Contaminación por halotano en el quirófano, con el uso de dos circuitos anestésicos: Circuito semicerrado y circuito semiabierto / Halothane pollution in operating room. a comparison using semiclosed and semiopen anesthetic circuits

Por cromatografía de gases, fue identificada y cuantificada la existencia de halotano en el área respiratoria del anestesiólogo y en la sangre del anestesiólogo, cirujano e instrumentista, durante el transcurso de un acto quirúrgico bajo anestesia general inhalatoria con halotano y el comportamiento de estos niveles durante una jornada de trabajo de 6 hrs, con el empleo de dos circuitos anestésicos: circuito semicerrado y circuito semiabierto. Los resultados muestran que los niveles de contaminación por halotano en el área respiratoria del anestesiólogo al final de una cirugía bajo anestesia general inhalatoria son similares con el uso de circuito semicerrado y semiabierto, siendo estos cuando menos 10 veces más altos que los valores permisibles por la NIOSH. Las concentraciones sanguíneas de halotano en el personal que integra el equipo quirúrgico son más altos cuando se utiliza el circuito semiabierto, y superan los niveles permisibles incluso para medio ambiente

Clinical evaluation of liver function after multiple and prolonged exposures either to halothane or isoflurance

Although halothane is the most widely volatile anaesthetic agent used in our country, halothane hepatitis is one of the important problems after the use of halothane. This study is designed to clarify the relation between halothane and liver affection and to compare this relation with that of isoflurane. Fourty patients of ASA grade I and II of both sexes were selected, ranging in age from 16 to 62 years, undergoing elective surgical procedures. All of them had no history of jaundice, liver disease, metabolic or systemic disorders. The patients were classified into two main groups: group I [halothane group] and group II [isoflurane group]. Each group was divided into two subgroups; one for multiple exposures and the other for prolonged exposure. For all patients, liver function tests were done preoperatively, 30 minutes postoperatively and after 7 days. The results obtained from this study showed no clinical or laboratory data of jaundice or hepatitis related to the anaesthetics used. All the changes were in the biochemistry and were within the normal range for each liver function tests. In comparison between the anaesthetic agents, it seems that isoflurane results were better than that of halothane results

Autonomic response in anaesthetized diabetic patients

The present study is carried out on thirty patients scheduled for various general surgical procedures not associated with significant change of intravascular volume. They were classified into 3 equal groups: Group I non diabetic as a control, group II diabetic patients admitted for elective surgery, and group III diabetic patients presented for emergency operations. They were tested preoperatively for autonomic dysfunction. The parasympathetic function tests were abnormal in all 20 diabetic patients studied of group II and III. But, the sympathetic function test was abnormal in 6 patients and 4 patients were in a borderline in group II. Non of the control patients had abnormal response to autonomic test. Anaesthesia was established with atropine, sodium thiopental and the intubation was facilitated with succinylcholine and maintained with halothane, oxygen nitrous oxide and flaxidel with mechanical ventilation. An anaesthesiologist, blinded to the autonomic test results recorded and monitored, preoperative, intraoperative and post operative, blood pressure, heart rate [HR] and mean arterial blood pressure [MABP]. Mean HR did not change after induction in each of diabetic groups, but increased in the control. After tracheal intubation mean HR increased significantly [P < 0.01] in control group, no change in group III but decreased significantly in group II. MABP decreased after induction in group I and then increased significantly after intubation, unchanged in group II. However, MABP decreased significantly after intubation in group III. It has been shown that intubation produced a less pressor response in diabetics than in normal patient. Fifty percent of diabetics required intraoperative vasopressors compared to control patients. Hemodynamic stability was difficult to control in diabetic groups during operation and after recovery especially group III as a poorly controlled diabetes. A major finding was that the diabetes who required intraoperative blood pressure support had a greater impairment of autonomic tests result compared with those diabetics who did not need vasopressors. Diabetics are at increased risk of cardiovascular lability during anaesthesia and preoperative screening of diabetics with simple non invasive autonomic tests may be useful in indentifying those at high risk for preoperative and postoperative cardiovascular instability

Cytogenetic analysis in peripheral lymphocytes of operating room personnel

The aim of this work is to study the association between occupational exposure to anesthetic gases and the presence of chromosomal damage as measured by chromosomal aberrations and sister chromatid exchanges [SCEs]. Twenty personnel [12 anesthesiologists and 8 nurses] were chosen from Ain Shams Speicalized Hospital. Cases were matched by age and sex with 16 controls; 10 of them were working as clerks at the same hospital and 6 were outside the hospital environment. Lymhocytic cultures were set up to and harvested at 48 hrs and 72 hrs for chromosomal aberrations and SCEs respectively. Halothane and Nitrous oxide were below the Maximum Allowable Concentration [MAC] levels. The percentage of chromosomal aberrations among exposed group was 2.2% compared to 1.2% among controls, [P < 0.05]. on excluding gaps the difference became insignificant. Also no difference was observed between inside and outside the hospital control groups. However, the frequency of chromosome type aberration was elevated among exposed group compared to control. Regarding SCEs, no statistical difference was proved, though the exposed smokers showed the highest value. These results suggest that more studies need to be conducted to evaluate health risk among personnel exposed to anesthetic gases

O efeito do sistema venturi na prevençao de poluiçäo de sala cirúrgica / The effect of the venturi system as an antipollution device in the operating room environment

Dois sistemas antipoluição são propostos e estudados comparativamente. Ambos foram constrídos com tubos de plástico rígido, que levam os gases expirados pelos pacientes para fora da sala de operação. A diferença entre os dois sistemas é dada pela presença ou ausência de um Venturi na extremidde que é externa à sala cirúrgica. O venturi consiste em dois troncos de cone, ligados por um duto paralelo entre suas secções menores. Neste estudo foram utilizados 60 cães adultos. Trinta destes cães (cães geradores) foram anestesiados com halotano a 1 por cento e submetidos à ventilação controlada mecânica com a finalidade de produzir poluição na sala de operação. Os 30 cães restantes (cães testemunhas) foram expostos à poluição ambiental da sala cirúrgica. Os cães testemunhas foram divididos em três grupos com 10 animais em cada grupo, sendo: grupo 1 (G1) - (controle) - sem sistema antipoluição; grupo 2 (G2) - com sistema antipoluição, sem Venturi, e grupo 3 (G3) - com sistema anitpoluição e Venturi. Estudaram-se os níveis de halotano por cromatografia gasosa tanto no ar de sala cirúrgica como no sangue dos cães testemunhas aos 30 (M1), 60 (M2) e 120 (M3) minutos após o início da anestesia. Observou-se que o aumento de halotano no ar e no sangue dos cães testemunhas foi diferente, sendo G1 > G2 > G3. Em G1, o nível de halotano já era alto em M1 tanto no ar como no sangue e sofreu aumento exponencial em M2 e M3. Em G2 e G3 o nível de halotano não se alterou durante a experiência (M1=M2=M3), porém os níveis de halotano em G2 foram anteriores que em G3. Houve 80 por cento de redução do nível de halotano em G2 e 95 por cento em G3, comparativamente a G1.