Psychiatric Assessment and Fundamentals Q 42
During electroconvulsive therapy (ECT) the client receives oxygen by mask via positive pressure ventilation. The nurse assisting with this procedure knows that positive pressure ventilation is necessary because?
A. Anesthesia is administered during the procedure.
B. Decreasing oxygen to the brain increases confusion and disorientation.
C. Grand mal seizure activity depresses respirations.
D. Muscle relaxations given to prevent injury during seizure activity depress respirations.
Correct Answer: D. Muscle relaxations given to prevent injury during seizure activity depress respirations.
A short-acting skeletal muscle relaxant such as succinylcholine (Anectine) is administered during this procedure to prevent injuries during seizure. A nerve stimulator is utilized to monitor succinylcholine, a depolarizing muscle relaxant used to reduce tonic-clonic contractions during the procedure. As an alternative to EMG, a blood pressure cuff is inflated on the patient’s ankle to prevent succinylcholine from entering the foot, allowing a visual monitor of seizure activity with measurement of tonic-clonic contractions.
Option A: ECT utilizes general anesthesia. Anesthetic induction medications used include barbiturates such as thiopental and methohexital and nonbarbiturate agents such as propofol and etomidate. Seizure-induced by ECT should last longer than 30 seconds. Methohexital is the most commonly used induction agent due to its quick onset, effectiveness, low cost, and minimal effect on seizure duration. Propofol and thiopental have been shown to reduce seizure duration. Etomidate has correlations with myoclonus and increased seizure duration.
Option B: Preoxygenation of the patient via nasal cannula or face mask is followed by anesthetic induction and paralysis. Administration of an anticholinergic medication before ECT may prevent arrhythmias such as bradycardia or asystole and excessive oral secretions. To induce cerebral vasoconstriction via hypocarbia, the patient is often hyperventilated via bag valve mask before delivery of the electrical stimulus to increase seizure intensity.
Option C: Skeletal muscle relaxation during ECT is integral to minimize a motor seizure and avoid musculoskeletal injury. The depolarizing neuromuscular relaxant succinylcholine is used at 0.75 to 1 mg/kg with an elimination half-life of 41 seconds. In cases where succinylcholine is contraindicated including neuromuscular disease or injury, burn injury, pseudocholinesterase deficiency or hyperkalemia, nondepolarizing neuromuscular relaxants are the preferred option.