Stages of anesthesia

With newer dragp and techniques, the stages of anesthesia may not be as prominent as those described in Display 35-1. In addition, movement through the first two stages is usually very rapid. 

Stage IV is the stage of respiratory paralysis and is a rare and dangerous stage of anesthesia. At this stage, respiratory arrest and cessation of all vital signs may occur. 

IV. Stage of medullary depression This deep stage of anesthesia includes severe depression of the CNS, including the vasomotor center in the medulla, as well as the respiratory center in the brain stem. Without circulatory and respiratory support, death rapidly ensues. 

Stage II—excitement The patient experiences delirium and violent combative behavior. There is a rise and irregularity in blood pressure. The respiratory rate may be increased. To avoid this stage of anesthesia, a short-acting barbiturate, such as sodium pentothal, is given intravenously before inhalation anesthesia is administered. 

The immediate effects of inhalant abuse are similar to the classic early stages of anesthesia. The sniffer is initially stimulated, excited, disinhibited, and prone to impulsive or reckless behavior. He may also feel lightheaded and, with successive inhalations, less inhibited and less in control. The speech of the user becomes slurred and gait becomes staggered, with similarities to intoxication by alcohol. Euphoria, often accompanied by hallucinations, also may... 

There are four stages of anesthesia that occur rapidly. These stages are ... 

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

The stage of anesthesia not reached by the patient is 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 various stages of anesthesia seem to be sponsored by the dose-dependent alteration of the physiology of different popnlations of neurons in the CNS. Furthermore, the various anesthetics do indeed show specificity in this respect. 

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