A child is posted for operative repair of exostrophy of bladder with renal failure. Which anesthetic should be preferred?
C i.e. Ataracurium In pediatric patients the choice of non depolarizing muscle relaxant depends on side effects and duration of action. The method of excretion of atracurium and cisatracurium (Hofman elimination and ester hydrolysis) makes these relaxants paicularly useful in newborns and children with liver or renal diseaseQ. If tachycardia is desired (eg with fentanyl anesthesia), pancuronium would be an appropriate choice. Vecuronium, atracurium, rocuronium & cisatracurium are useful for shoer procedures. Rocuronium offers an advantage that it can be administered intramuscularly (like Sch) preferably in deltoid however, the duration of action is - 1 hour, which could be a distinct disadvantage for a brief procedure. Vecuronium is valuable because no histamine is released; however, its duration of action is prolonged in newborns, which makes it similar to pancuronium The potential for rhabdomyolysis & hyperkalemia (paicularly in boys < 8 yrs who may have unrecognized muscular dystrophy), as well as for masseter spasm (jaws of steel), malignant hypehermia, cardiac arrhythmias, and myoglobinemia after administration of succinyl choline suggests that Sch should not be used routinely in children. Unlike adult patients profound bradycardia & sinus node arrest can develop in pediatric patients following 1st dose of Sch without atropine pretreatment. If a child unexpectedly experiences cardiac arrest following Sch administration, immediate treatment for hyperkalemia should be instituted. Howeve, it is the only available ultrasho acting muscle relaxant that provides a dependable, rapid onset of action. IV use of Sch should be limited to children who have full stomach or to treat laryngospasm. Intramuscular, intralingual (Submental) use is indicated for children with difficult intravenous access when control of airway is deemed essential. Mivacurium is an alternative to Sch when profound neuromuscular block of sho duration is required but rapid onset of action is unnecessary. Antagonism of neuromuscular blockade in all neonates & small infants, is recommended, even if they have recovered clinically, because any increase in work of breathing may cause fatigue and respiratory failure. Sugammadex, a cyclodextrin whose endoskeleton forms a water soluble complex with exoskeleton of rocuronium, is designed to antagonize the effects of rocuronium. As it is made of sugars and antagonize by covalent bonding the side effects are minimal. Antagonism is more rapid than neostigmine/atropine. It also reverse the other steroidal relaxants vecuronium & pancuronium to a lesser extent. The mechanism of reversal is lowering of plasma conentation & thus reversing the concentration gradient and pulling the rocuronium off the myoneural junction.
Pancuronium
Vecuronium
Ataracurium
Rocuronium