Biomedical subjects
Publications and source records attributed to N Stojeba.
We report a case of a major venous argon embolism during argon beam coagulation of a liver biopsy. The essential signs were an abrupt reduction in end-tidal carbon dioxide partial pressure, in SpO2 and in systolic arterial pressure, at the time of coagulation. Spontaneous recovery was observed within 10 min. Precautions in respect of usage are highlighted.
OBJECTIVE: To investigate the efficacy of urapidil, administered either by boluses or a continuous infusion, to control hypertension during resection of phaeochromocytoma. STUDY DESIGN: Prospective open study. PATIENTS: Seven consecutive patients aged between 23 and 60 years, with a hypersecretant phaeochromocytoma. METHODS: Standard anaesthetic technique including thiopentone, opioid, muscle relaxant, nitrous oxide and isoflurane. Invasive haemodynamic monitoring with a Swan-Ganz catheter and radial arterial catheterization. Infusion of cristalloids and colloids (20 mL.kg-1.h-1). Evaluation of two regimens of urapidil administration following the initial injection of a bolus of 25 mg in case of severe hypertension i.e. SAP > 180 mmHg > 1 min: a) boluses of 25 or 50 mg of urapidil injected according to the response obtained after the first bolus or in case of resurgence of a new hypertensive event; b) continuous infusion of 150-200 mg.h-1. RESULTS: Three patients developed hypertension between the induction of anaesthesia and the beginning of the tumor dissection. One bolus of 25 or 50 mg of urapidil was efficient to control this event. During the dissection of the phaechromocytoma, higher doses (75-100 mg) were required to significantly decrease SAP and DAP values (P < 0.001). Heart rate did not change significantly in patients not receiving esmolol. A continuous infusion, used in three patients, did not prevent the occurrence of peaks in two patients, requiring additional doses. After the removal of the tumor, three patients experienced severe hypotension with decreased systemic vascular resistances and high cardiac output. Vasoactive drugs were injected to restore better haemodynamic conditions. CONCLUSION: Urapidil is useful for the management of hypertension during the resection of phaechromocytoma. However further investigations are needed to determine its role in the occurrence of prolonged collapse after the tumor removal.
Since the introduction of first generation automatic implantable cardioverter defibrillators (AICD) in 1980, an increasing number of such devices have been inserted in patients at high risk for sudden death by ventricular tachycardia or fibrillation (VT/VF). With the improvement of technology and implanting techniques, devices may be inserted at present subcutaneously into the abdominal or the thoracic wall, rather than by thoracotomy. The anaesthesist is involved in the primary implantation of the AICD and the secondary testing of efficiency. Implantation generally requires general anaesthesia and the extension of monitoring is guided by the patient's underlying disease(s). The efficiency of the implanted system is tested one to two months later in inducing VT/VF under general anaesthesia and in determining the defibrillation threshold. The anaesthetist may also have to take care of patients with a AICD. For such cases the following recommendations can be made: a) gloves should be worn by doctors and nurses coming into contact with these patients, in order to limit the risk of electrification; b) a ring magnet must be available to inactivate the unit; c) in case of external defibrillation, the external paddles should be oriented perpendicularly to the line joining the two implanted electrodes; d) AICD should be disabled during electrocautery and prior to electroconvulsive therapy; e) the assistance of a electrophysiologist may be helpful for the management of these patients.
Magnetic resonance imaging (MRI) requires the patients to stay for 30-45 min in a magnetic closed noisy space. Therefore most children and agitated adults require general anaesthesia or sedation in order to high quality images. Anaesthesia may be given by several routes (TIVA, inhalational or intrarectal administration) using common drugs. However, the magnetic field limits the selection of patients undergoing MRI and the spectrum of anaesthetic and monitoring equipment. The magnetic field may have deleterious effects on implanted ferromagnetic devices. It may attract objects towards the magnet centre at a dangerous speed. Moreover it may disturb the function of monitors and anaesthesia machines which should be tested for a specific magnetic field strength before introducing their use in a given MRI unit.