[Cardiocirculatory effects of halothane and isoflurane in respiratory distress caused by oleic acid]. / Efectos cardiocirculatorios del halotano e isoflurano en el distrés respiratorio producido por ácido oleico.

INTRODUCTION: When lungs are damaged or affected by edema they behave differently from healthy lungs in the presence of drugs that can modify vascular reactivity. OBJECTIVES: To determine the effects of halothane and isoflurane on pulmonary edema induced by oleic acid in dogs. MATERIAL AND METHODS: Eighteen dogs were anesthetized with sodium pentothal. Hemodynamic and lung parameters as well as end-tidal gases were monitored. Pulmonary edema was induced with an injection of oleic acid (0.1 ml/kg). Five periods were studied: 1) before injection of oleic acid; 2) 90 min after injection; 3) 20 min after ventilation with 1 MAC halothane or isoflurane; 4) 20 min after 2 MAC ventilation with the assigned anesthetic, and 5) 20 min after withdrawal of anesthetic. RESULTS: With halothane, cardiac output and arterial blood pressure decreased significantly. With isoflurane, arterial pressure decreased by way of changes in vascular resistance. Neither anesthetic affected hypoxic pulmonary vasoconstriction. CONCLUSIONS: Neither anesthetic worsens arterial oxygenation in a model of pulmonary edema that is similar to adult respiratory distress.

[Carotid endarterectomy with Javid bypass and supraorbital photoplethysmography]. / Endarterectomía carotídea con cortocircuito de Javid y fotopletismografía supraorbitaria.

Bypass patency was monitorized by photoplethismography of supraorbital artery during Javid's bypass clamping in the course of carotid endarterectomy in 12 patients. This technique allows a rapid and easy detection of partial or total bypass occlusion which is manifested by a reduction in the plethysmographic wave amplitude in the ipsilateral supraorbital artery with respect to data obtained before operation or with the plethysmographic curve recorded at the contralateral artery. Among the twelve patients only five (41.6%) showed no evidence of bypass malfunction. Two patients (16.6%) suffered one episode of bypass insufficiency, four (33.3%) patients presented three episodes and one patient (8.33%) complained four episodes of bypass dysfunction. None of bypass dysfunctions were detected by the surgical team. Bypass insufficiency was due to excessive traction that caused leaning of the vessel or to malposition of the end of the bypass. Both were promptly corrected. We conclude that besides implantation of the bypass it is worthwhile monitoring its function by recording the photoplethysmographic response of the supraorbital artery which, in turn, is a safe and easy technique.