Effect on free radical generation with different anaesthesia.

Reactive oxygen species are a part of the normal physiology of the biological system but their subsequent defence undergoes alteration during diseased conditions. Administration of anaesthesia for surgery may also alter the formation of reactive oxygen species. The present work deals with the comparative status of oxidative stress (lipid peroxidation) and anti-oxidant defence markers (superoxide dismutase and catalase) in blood in 3 groups of 15 patients each receiving halothane, relaxant vecuronium and spinal form of anaesthesia with lignocaine 5% heavy. The results obtained depict that the formation of malonyl dialdehyde as well as decrease in superoxide dismutase and catalase activities was highest in spinal anaesthesia followed by halothane and then relaxant group. Therefore, it seems important to consider the pre-operative anti-oxidant status while administering anaesthesia to such patients in order to provide biologically safe anaesthesia.

Respostas circulatórias à induçåo e intubaçåo traqueal com associaçåo de vecurônio ao tiopental ou etomidato / Circulatory responses to induction and tracheal intubation under vecuronium associated with thiopental or etomidate

Background and Objectives - Vecuronium has been shown to cause minimum cardiovascular effects. However, some authors have demonstrated bradycardia associated with its use. The purpose of this study was evaluate the changes in arterial blood pressure and heart rate following the use of vecuronium, in patients induced with etomidate or thiopental. Methods - Forty adult patients submitted to elective surgical procedures were studied and were allocated into 4 groups as folows: Group NT = 10 normotensive patients induced with thiopental; Group NE = 10 normotensive patients induced with etomidate; Group HT = 10 hypertensive patients induced with thiopental; Group HE = 10 hypertensive patients induced with etomidate. All patients were sedated with diazepan and fentanyl, and received fentanyl and vecuronium during induction, besides the specific induction agent for each group. Systolic and diastolic blood pressure and heart rate were evaluated at six consecutive moments: M1 = control, beforeinduction; M2 = two minutes following sedation; M3 = immediately following induction; M4 = one minute following orotracheal intubation; M5 = three minutes following orotracheal intubation. M6 = six minutes following orotracheal intubation. Results - Anthropometric data were similar in all groups (p<0.05). Systolic and diastolic blood pressures were evaluated separetely and a statistically significant decrease was observed at moment 3, as compared to moments 1 and 2, although the values were not clinically relevant in any of the groups. Regarding heart rate, statistically significant decreases were observed in the groups induced with etomidate (NE and HE). Conclusions - It is concluded that vecuronium is associated with stable blood pressure. Heart rate is decreased following the vecuronium-etomidate association, both in normotensive and hypertensive patients

Edema pulmonar agudo después de la administración de naloxona / Acute pulmonary edema following administration of naloxone

La administración de opiaceos provoca depresión respiratoria, que puede prolongarse en el periodo postoperatorio por lo que es conveniente la vigilancia estrecha del paciente o la administración de drogas antagonistas tales como la naloxona. Se presenta un caso de edema agudo pulmonar posterior a la administración de naloxona en un paciente femenino de 36 años de edad y aparentemente sin antecedentes patológicos predisponentes para esta complicación. La paciente fue programada para polipectomia nasal, la cual se realizó bajo anestesia general endovenosa. Durante el procedimiento fueron utilizados, propofol en infusión como anestésico, vecuronio como relajante muscular y fentanyl como analgésico. Al terminar la cirugía, la paciente presentó depresión respiratoria y miosis, por lo que se decidió antagonizar los efectos del opiaceo con dosis relativamente bajas de naloxona. Cinco minutos depués de haber ingresado a la sala de recuperación la paciente presenta datos compatibles con edema agudo pulmonar, por lo que, se inicia el tratamiento antiedema y treinta minutos después, la paciente presenta mejoría. Posteriormente continúa su tratamiento en la Terapia Intensiva de donde es egresada dos días después en completa mejoría y continúa su observación en la consulta externa de su clínica.

Nuevos agentes relajantes musculares / New muscular relaxing agents

Desde los primeros extractos naturales curarinicos, hasta los analogos sinteticos aparecidos posteriormente, distintos farmacos han sido descritos como capaces de bloquear la transmision muscular. Aparte de la eficacia, todos estos farmacos presentan como denominador cumun efectos colaterales, generalmente como interferencia con el sistema nervioso autonomo, ademas de la desventaja de ser dependientes del higado y rinones para su metabolismo y eliminacion. Esto ha motivado a investigadores de la ultima decada, a realizar innovaciones en la estructura de los agentes bloqueadores no despolarizantes, tratando de obviar los inconvenientes que presentan los agentes ya conocidos, y poder brindar un manejo mas adecuado y seguro a los pacientes que requieren este tipo de medicacion..