What is the expected response after administering a test dose of edrophonium in a client suspected of having myasthenia gravis?

Administering a test dose of edrophonium, which is a short-acting acetylcholinesterase inhibitor, is a diagnostic procedure used to identify myasthenia gravis. When edrophonium is given, it prevents the breakdown of acetylcholine, leading to an increase in its availability at the neuromuscular junction. This results in an improvement in muscle strength, specifically due to the enhanced stimulation of the receptors on the muscle side of the synapse.

In the context of myasthenia gravis, where there is an autoimmune attack on the acetylcholine receptors, this increase in acetylcholine can temporarily overcome the effects of this impairment. Patients typically show a noticeable improvement in muscle strength within 1 to 3 minutes after administration of edrophonium, confirming the diagnosis of myasthenia gravis if the expected response occurs. This is the reason why the expected response after administering edrophonium is an increase in muscle strength within a short timeframe.