Medullary paralysis

Stage IV. Medullary Paralysis. This stage is marked by the cessation of spontaneous respiration because respiratory control centers located in the medulla oblongata are inhibited by excessive anesthesia. The ability of the medullary vasomotor center to regulate blood pressure is also affected, and cardiovascular collapse ensues. If this stage is inadvertently reached during anesthesia, respiratory and circulatory support must be provided or the patient will die.39... 

Stage IV—medullary paralysis Severe depression of the respiratory center and vasomotor center occur during this stage. Death can rapidly ensue. 

In doses used clinically (0,5-1.0 mg), this effect is usually confined to mild vagal excitation. The rate and occasionally the depth of breathing are increased, but this effect is probably the result of bronchlolar dilatation and the consequent Increase in physiologic "dead space." With toxic doses of atropine, central excitation becomes more pronflnent, leading to restlessness, irritability, disorientation, hallucinations, or delirium. With still larger doses, stimulation is followed by depression, coma, and medullary paralysis. The latter may be primarily responsible for a fatal outcome. Even moderate doses of atropine may depress some central motor mechanisms that control muscle tone and movement. 

Medullary Paralysis The respiratory center (medulla oblongata) becomes paralyzed. Breathing and vital functions cease. Death occurs. However, the anesthetist adjusts the general anesthetic to prevent the patient from reaching this stage. 

The four stages of anesthesia are analgesia, excitement, surgical anesthesia, and medullary paralysis. 

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