Precurarización con rocuronio y d-tubocurarina: otra perspectiva / Precurarization with rocuronium and d-tubocurarine

Objetivo: Estudiar la precurarización de la succinilcolina utilizando d-tubocurarina y rocuronio introduciendo los métodos restrictivo, conceptos de velocidad de acción y recuperación y una nueva semiología para evaluar las fasciculaciones. Material y método: Se administraron succinilcolina (1 mg x Kg-1) (n =21) sola o precedida por rocuronio o d-tubocurarina (60 ó 50 ug x Kg-1) (n =21 c/u), determinándose: la fase inicial de comienzo hasta 80 por ciento de bloqueo, tiempo de comienzo, máximo efecto, duración clínica, tiempo de reversión espontánea entre 10 por ciento y 25 por ciento y 25 por ciento a 50 por ciento. Se calculó la velocidad de acción (inicial, final y global) como la relación tiempo/bloqueo fraccionado y la velocidad de recuperación. El método restrictivo fue empleado para el estudio del tiempo de comienzo, utilizando un rango restringido de bloqueo. Las fasciculaciones fueron evaluadas por su intensidad en seis regiones anatómicas por cuatro observadores imparciales e independientes y las medias de sus valoraciones utilizadas para analizarlas. Resultados: Aparentemente ambos desfasciculantes prolongan la fase inicial, tiempo de comienzo y velocidad de la succinilcolina, pero el método restrictivo únicamente lo confirmó para el tiempo de comienzo y la velocidad global. La velocidad inicial fue más rápida que la final. El rocuronio redujo el efecto y la duración clínica e incrementó la velocidad de recuperación de la succinilcolina. Las fasciculaciones fueron más frecuentes e intensas en el tronco y miembro superior izquierdo, pero los precurarizantes las redujeron tanto en intensidad como localización Discusión: La precurarización no modifica la fase inicial de comienzo, surgiendo la posibilidad de practicar una intubación temprana. Debido al acortamiento que provoca la precurarización con rocuronio se hace evidente la necesidad precoz de nuevas dosis de relajantes.

Objective: To study the precurarization of succinylcholine with d-tubocurarine and rocuronium, using the restrictive method, speed of action and recovery principles and a particular evaluation for fasciculations Material & Methods: Patients received succinylcholine (1 mg x Kg-1) (n =21) either alone or preceded by d-tubocurarine or rocuronium (60 ó 50 micron g x Kg-1) (n =21 e/a), and the following clinical measurements were made: earlyphase of onset time (up to 80 percent blockade), onset time, maximal block, clinical duration and recovery time between 10 percent and 25 percent and 25 percent to 50 percent. Speed of action (initial, final and global)as the ratio between time and fractional blockade and speed of recovery, were calculated. Restrictive method was used for the study of the entire onset time on patients included in a limited range of final block. Intensity of fasciculations was evaluated by four independent observers blind to the drugs used in six anatomical regions and their mean values used for analysis. Results: Apparently, precurarizing drugs prolonged initial phase, onset time and reduced speed for succinylcholine, but only onset time and global speed were confirmed by restrictive method. After rocuronium, maximal effect as well as clinical duration of succinylcholine werereduced and speed of recovery increased. Fasciculations were more frequent and intense at the trunk and left upper arm, but precurarization reduced both intensity and localization prevalence. Discussion: As lack of changes on the initial phase of onset time for succinylcholine inducedby precurarization was noticed, an early tracheal intubation could be contemplated. Due to reduction on clinical duration after rocuronium,new doses of muscle relaxants are sooner necessary. The present method for evaluation of fasciculations shows how far they are spread and how effective precurarization was, given rise to doubts on previous results.

Malignant hyperthermia: a case report in Thai Anesthesia Incidents Study (THAI Study).

A 3-year-old Thai boy underwent open reduction and internal fixation with K-wire of condylar fracture of humerus under general anesthesia. The patients developed generalized muscle regidity, masseter muscle spasm, elevated creatinine kinase, high temperature (39.3 C), inappropriate tachycardia, and arterial base excess was more than-8 mEq/L. The clinical grading scale of diagnosis of malignant hyperthermia was 58 (grade D6; almost certain malignant hyperthermia). Succinylcholine has been identified as the trigger agent, as other possible trigger agents were not involved. The treatment included hyperventilation, external cooling and cold IV fluids without administration of dantrolene. The patient fully recovered and discharged on day 12. This case report showed an incidence of malignant hyperthermia of approximated 1:150,000 in Thai Anesthesia Incidents Study (THAI Study).

Can lidocaine reduce succinylcholine induced postoperative myalgia?

This study was undertaken to determine the effect of lidocaine pretreatment on reduction of succinylcholine-induced myalgia in patients undergoing general anesthesia for gynecological surgery. One hundred and thirty-five patients were assigned to one of three groups in a prospective, double blind, randomized manner. Group PS, the control group, received normal saline and succinylcholine 1.5 mg x kg(-1); Group LS, lidocaine 1.5 mg x kg(-1) and succinylcholine 1.5 mg x kg(-1); Group PR, normal saline and rocuronium 0.6 mg x kg(-1). Morphine 0.1 mg x kg(-1) iv was given for premedication and all patients were monitored with a noninvasive blood pressure monitor, ECG and pulse oximetry. Anesthesia was induced with 5 mg.kg(-1) thiopental iv. followed by succinylcholine (Group PS, LS) or rocuronium (Group PR) for tracheal intubation. Following administration of these agents, the presence, and degree of fasciculation were assessed visually on a four point scale by one investigator who was blinded to the drug administered. The blood pressure and heart rate of each patient were monitored on nine occasions. Twenty-four hours later, any myalgia experienced was assessed according to a structured questionaire and graded by a four point scale by one investigator blinded to the intraoperative management. The results indicate that muscle fasciculation was not found in Group PR while the patients in Group LS had a lower incidence of muscle fasciculation than those in Group PS (p < 0.001). At 24 h, the incidence of myalgia was higher in Group PS than in Group LS and PR (p < 0.05). A correlation was not found between the incidence of myalgia and the occurrence of muscle fasciculation. The changes in systolic and diastolic blood pressure and heart rate were not significant among the three groups. In conclusion, where succinylcholine is used, lidocaine is proven to be the useful pretreatment agent for the reduction of postoperative myalgia.

Variation of serum potassium and creatinine phosphokinase levels in suxamethonium-induced muscle relaxation.

Popular depolarising muscle relaxant, suxamethonium (succinylcholine chloride), produces fasciculation in group of muscles and 'after pain'. Mode of its action is neuromuscular blockage. It also may be associated with muscle fibre injury and altered membrane permeability. These may cause rise of serum K+ and creatinine phosphokinase (CPK) levels. But use of diazepam either during or as pretreatment may reduce the fasciculation, 'after pain' and rise of K+ and CPK levels. Present study was undertaken to show whether any correlation of the degree of fasciculation and postsuxamethonium myalgia is present or not and whether diazepam has any role in reducing muscle injury and in turn reducing the levels of serum K+ and CPK.