[Postoperative lesions of the peripheral nerves. 8 years' analysis]. / Lesiones postoperatorias de los nervios periféricos. Análisis de 8 años.

Damage to a plexus or peripheral nerve is a rare and avoidable complication of surgical anesthesia. We reviewed 2,750 case histories of patients who underwent surgery between 1985 and 1992, finding 6 cases of nerve lesions presenting postoperatively. Sequelae involved 1 abdomino-genital neuralgia, 1 case of post-epidural radicular pain, 2 cases of peroneal nerve palsies and 2 of cubital paresis. Three of these cases were related to position during surgery, 1 to position during a prolonged period in bed in the intensive care unit, 1 to the anesthetic technique and 1 to surgical manipulation. Our data are important given the difficulty of studying the incidence of such cases due to patient dispersion and the loss of records of possible occurrences. The mechanisms by which lesions are produced are sometimes difficult to pinpoint but all are generally preventable.

[Adenosine triphosphate in the peroperative management of hypertensive crises and heart rate disorders in the surgical treatment of pheochromocytoma]. / Adenosintrifosfato en el manejo peroperatorio de las crisis hipertensivas y trastornos del ritmo cardíaco en la cirugía del feocromocitoma.

OBJECTIVE: To assess the hypotensive and antiarrhythmic effect of adenosine triphosphate (ATP) and its impact on hypertensive crises and heart rhythm abnormalities resulting from surgery to remove pheochromocytoma. PATIENTS AND METHODS: A prospective study of 7 patients with pheocromocytoma who were scheduled for unilateral (4) or bilateral (3) suprarenalectomy prior to treatment with phenoxybenzamine and propranolol. The anesthetic procedure was the same for all patients, as was monitoring: ECG, digital pulse oximetry, capnography, direct recording of arterial pressure by a catheter in the left radial artery and a Swan-Ganz fiber optic catheter in the pulmonary artery to measure pulmonary pressures and mixed venous oxygen saturation. Minute volume was measured by thermodilution. Blood glucose levels and urine excreted through a catheter were recorded hourly during surgery. During surgery, when arterial pressure had risen 20% above baseline level, i.v. infusion of ATP 0.5 mg/kg/min was begun and adjusted up or down depending on patient response. Infusion was stopped when the suprarenal vein had been tied. Hemodynamic analysis was performed during 4 phases: 1) start of surgery; 2) during manipulation of the tumor; 3) after excision, and 4) after surgery. Hemodynamic and metabolic variables were recorded, as were ATP doses and requirements for vasopressors and antiarrhythmic drugs. RESULTS: We found the following changes between phase 1 and phase 2, coinciding with ATP infusion: systemic arterial pressure increased 22.2%, heart rate increased 28.04% (with no cardiac arrhythmia observed in any patient), pulmonary artery pressure rose 25.35%, pulmonary capillary pressure rose 22.17%, cardiac index rose 108% while systemic vascular resistance decreased 55.82% and pulmonary vascular resistance decreased 33.96%.(ABSTRACT TRUNCATED AT 250 WORDS)

[Thalassemic syndromes and anesthesia]. / Síndromes talasémicos y anestesia.

Thalassemic syndromes are produced by a quantitative defect in the synthesis of globin chains of hemoglobin. They are classified according to the severity of the clinical picture and to the type of globin chain that is affected. Physiopathology, clinical picture, and treatment of thalassemias are discussed in this work. Thalassemia minor does not create, in general, anesthetic problems. In cases of thalassemia major one should consider not only problems derived from the severity of the anemia it self, but also those related to transfusional therapy, and to bony malformations that may disturb tracheal intubation. Discussion on the management of homozygotic thalassemia during the pre, per, and postoperative phase completes this revision.

[Prognostic factors for postoperative mortality in cancer of the esophagus. Analysis of 46 cases]. / Factores pronósticos de la mortalidad postoperatoria del cáncer de esófago. Análisis de 46 casos.

Forty six patients with esophageal cancer underwent surgery between January 1986 and January 1990. In 14 patients (30.4%) distant metastases were recognized before surgery, whereas in 29 cases (63%) regional neoplastic lymph node infiltration was observed during surgery. Complications during and after surgery occurred in 32 (69.6%) patients and in 30 cases (65.2%) respectively. During the first 30 days after surgery 12 patients died. This represents a postoperative mortality of 26.1%. Among a total number of 51 variables analyzed in this study, 11 influenced the postoperative mortality: duration of intubation, previous history of toxic syndrome, presence of distant metastases before surgery, presence of neoplastic node involvement during surgery, tumor size greater than 4 cm, localization of the tumor at the middle third of the esophagus, respiratory insufficiency, cardiac failure, septic shock, and suture failure during the postoperative phase. However, multivariate analysis revealed that only three of these variables had an independent prognostic value on postoperative mortality: tumor size, presence of distant metastases, and development of respiratory insufficiency during the postoperative period.

[Comparative study of the efficacy and tolerance of propofol and thiopental in induction and in continuous perfusion with neuroleptanesthesia]. / Estudio comparativo de eficacia y tolerancia de propofol con tiopental en la inducción y en perfusión continua con la neuroleptoanestesia.

We have studied 40 ASA I/II patients aged from 18 to 65 years undergoing otorhinolaryngologic surgery of 40-100 minutes of duration. Patients were randomly assigned to two groups. Anesthesia in group I was induced with thiopental, 4 mg/kg and maintained with N2O at 66% and a variable perfusion of fentanyl. In group II, anesthesia was induced with propofol, 2.5 mg/kg and maintained with a perfusion of 6-12 mg/kg/hour and an initial perfusion of fentanyl, 4 micrograms/kg/hour. Loss of consciousness occurred in 37.49 +/- 9.78 seconds in group I and in 46.25 +/- 12.62 seconds in group II, with no significant differences. Two minutes after induction, propofol group presented a significant decrease in systolic blood pressure of - 12 mm Hg and both groups presented comparable increases in systolic blood pressure and heart rate during intubation. Five minutes later, systolic blood pressure regained normal values. Maintenance in group II was achieved in a proper fashion with a mean propofol consumption of 9.5 +/- 2.6 mg/kg/hour and fentanyl consumption of 4.94 +/- 2.22 micrograms/kg/hour whereas in group II, with N2O at 66%, the amount of fentanyl required was 6.85 +/- 2.95 micrograms/kg/hour, which was significantly higher. Eye opening from the time of interruption of anesthetics was achieved at 6.6 +/- 3.2 minutes in group I and 12.44 +/- 6.34 in group II. Consciousness was regained at 11.25 +/- 3.96 and 16.87 +/- 6.95 minutes, respectively. Pain on injection occurred in 15% with propofol and in 10% with thiopental. No patient presented major complications nor phlebitis after administration of the anesthetic.

[Anesthetic approach in 2 patients with pulmonary lymphangiomyomatosis]. / Conducta anestésica en 2 pacientes afectadas de linfangiomiomatosis pulmonar.

Pulmonary lymphangiomyomatosis (PLM) is an idiopathic disease of females in fertile age. It results in respiratory failure characterized by obliteration of the small airways, emphysema, formation of bullae, hemoptysis, pneumothorax, pulmonary fibrosis, severe hypoxemia and reduced carbon monoxide diffusion capacity. The major lymphatic ducts are also involved, resulting in chylous pleural effusion and ascites. Pulmonary abnormalities improve objectively and subjectively after surgical therapy, which consists in bilateral oophorectomy. Its evolution results in death in no more than 10 years. We report the anesthetic approach to 2 patients with PLM. Patient 1 was a female who had already been diagnosed of PLM and had received medical and surgical therapy, requiring reoperation for the resection of cystic intestinal masses and abdominal eventration. Patient 2 had been scheduled for bilateral oophorectomy after a diagnosis of PLM. We discuss the clinical condition of both patients, the course of the disease, the previous treatments and the anesthetic technique in each case.

[A rare complication of endotracheal intubation: posterior luxation of the left arytenoid cartilage]. / Una complicación poco frecuente de la intubación endotraqueal: la luxación posterior del aritenoides izquierdo.

The luxation of the arytenoid cartilage is a very uncommon complication of endotracheal intubation. Symptoms usually are aphonia, dysphonia, pain or discomfort in the throat, odynophagia and laryngeal stridor. It may be due to several factors: the pressure of the convex aspect of the tube on the arytenoid, traumatic or prolonged intubations, reintubations within a short period, or some systemic diseases. We report a case of posterior luxation of the left arytenoid in a patient who had been anesthetized for the radical cure of a left inguinal hernia. The clinical features developed when he recovered from anesthesia, with aphonia and discomfort in the throat. The diagnosis was made by indirect laryngoscopy. Treatment with nonsteroidal antiinflammatory agents was instituted. Aphonia disappeared after 2 weeks and dysphonia persisted. The patient became asymptomatic with corticosteroids on the fourth week after operation. Early diagnosis under laryngoscopic vision is recommended, with adequate therapy to prevent fibrosis of the cricoarytenoid joint with permanent sequelae.

[Anesthesia in insulinoma surgery: report of 18 cases]. / Anestesia en la cirugía del insulinoma: a propósito de 18 casos.

We reviewed 18 patients operated on insulinoma during the last 16 years (1974-1990). The previous symptoms, the clinical and biochemical diagnostic procedures, the localization before and during operation, and the medical and surgical treatment are reported. Constant and continuous glucose solution perfusion at the preoperative stage prevented the occurrence of hypoglicemia without interference with the rebound hyperglicemia that follows tumor exeresis. Neuroleptanalgesia with nitrogen protoxide and competitive muscular relaxant agents was satisfactory in all instances. Prevention and treatment of postoperative complications are also discussed in this study.

[Myasthenia gravis]. / Miastenia grave.

The present review updates myasthenia gravis. Immunopathogenesis of this condition, the clinical picture and degrees of involvement according to Osserman's classification, diagnostic procedures currently available, medical treatment and repercussion on the patient who is going yo be thymectomized are discussed. We review the works of several authors as far as concern to the use of muscle relaxants in myasthenic patients, peroperative monitoring of neuromuscular blockade, anesthetic techniques to be used, analgesia and intensive care required during postoperative period.

[Myasthenia gravis: thymectomy. Muscle relaxation with atracurium besilate]. / Miastenia grave: timectomía. Relajación muscular con besilato de atracurio.

We have carried out a prospective study on the use of the muscle relaxant, atracurium besilate, in 10 patients with myasthenia gravis, seven had type IIB and three had type IIA, who were scheduled for thymectomy, using ED95 0.20 mg/kg, and ten non myasthenic patients undergoing cholecystectomy using ED95 0.50 mg/kg. After monitoring neuromuscular transmission, the time for establishing maximum blockade (EMB), clinical efficacy time (CET), recovery index (RI) and total duration time (TDT) were measured and evaluated comparatively. Results showed that in myasthenics patients, EMB was faster, CET an TDT were more prolonged and RI was higher than in non myasthenic patients. We conclude that atracurium at doses of 0.20 mg/kg is currently the non depolarizing muscle relaxant of choice in myasthenic patients because of the excellent muscle relaxation allowing extubation in the operating room without reverting muscle blockade and not needing ventilatory support during postoperative period.

[Evaluation of the degree of muscle blockade: a comparative study using electromyography of the muscular relaxation induced by pancuronium, atracurium and vecuronium]. / Evaluación del grado de bloqueo muscular: estudio comparativo mediante electromiografía de la relajación muscular provocada por el pancuronio, atracurio y vecuronio.

To compare the muscle relaxing effect of pancuronium, atracurium and vecuronium, 99 patients operated on under neuroleptanesthesia were divided in three groups depending on whether they had received, during induction, pancuronium 0.1 mg/kg, atracurium 0.5 mg/kg, or vecuronium 0.1 mg/kg. One-fourth of the initial dose was repeated if necessary. The electromyographic study of the muscle relaxing effect was carried out with stimulation of the cubital nerve with courses of supramaximal square wave electric stimuli in 'trains of four'. The time to maximal blockade (TMB), the time of clinical effectiveness (TCE), the total duration time (TDT), the time of duration of the maintenance dose (DM 25) and the recovery index (RI) were measured. TMB was 4.3 +/- 1 min for pancuronium, 3.5 +/- 0.8 min for atracurium, and 3.3 +/- 0.98 min for vecuronium. The differences between pancuronium and the other drugs were statistically significant, but they were not so between the latter two. TCE was 67.9 +/- 13.5 min for pancuronium, significantly longer than with vecuronium and atracurium (28.2 +/- 5.7 and 31.5 +/- 4.7, respectively). TDT was 126.2 +/- 19.9 min for pancuronium, 61.2 +/- 11.5 min for atracurium and 55.5 +/- 16.7 for vecuronium. The mean duration of the repeated dose was 52.7 +/- 8.4 min for pancuronium, 19.9 +/- 5 min for vecuronium and 10.9 +/- 5 min for atracurium. RI, which was similar for atracurium and vecuronium (12.7 +/- 1.7 min and 12.8 +/- 3.3 min), was longer for pancuronium (27.7 +/- 4.3 min).

[Pheochromocytoma: review of the preoperative treatment and anesthesiologic technic in 14 patients]. / Feocromocitoma: revisión del tratamiento preoperatorio y técnica anestésica en 14 pacientes.

Fourteen patients operated for pheochromocytoma from 1978 to 1988 are reviewed. The preoperative treatment with adrenergic blockers is analyzed: phenoxybenzamine with final doses of 10-140 mg/day (mean 55.4 mg/day) and propranolol with doses of 40-80 mg/day (mean 50 mg/day). The premedications and anesthetic techniques are compared, the use of droperidol being discouraged because of the development of hypertensive paroxysms both preoperatively and postoperatively. The new benzodiazepines are offered as an alternative. The treatment of hypertensive paroxysms with phentolamine with total doses of 2.5-35 mg and that of peroperative arrhythmias with propranolol with total doses of 1-6 mg are reported. The recently described therapeutic approaches are also discussed.