Why can muscle-relaxing drugs require mechanical breathing support?

Muscle-relaxing drugs, known as neuromuscular blocking agents, require mechanical breathing support because they function by interrupting the transmission of nerve impulses to skeletal muscles.12

These drugs act at the neuromuscular junction to prevent the neurotransmitter acetylcholine from stimulating muscle contraction. While this effect is useful for surgeons to achieve deep muscle relaxation during procedures, it also paralyzes the muscles involved in respiration, such as the diaphragm and chest muscles. Because these muscles are essential for natural breathing, their paralysis prevents the patient from moving air in and out of the lungs independently.123

Consequently, mechanical ventilation is necessary to perform the work of breathing for the patient, ensuring the continued exchange of oxygen and carbon dioxide until the effects of the muscle relaxants wear off or are reversed.134