Stage of analgesia in anaesthesia is -

Guedel's classification is a means of assessing of depth of general anesthesia introduced by Ahur Ernest Guedel for Ether in1937. Stage I (stage of analgesia or disorientation) Stage II (stage of excitement or delirium) Stage III (stage of surgical anesthesia) plane I to IV Stage IV: from stoppage of respiration till death Stage III (stage of surgical anesthesia): from onset of automatic respiration to respiratory paralysis. It is divided into four planes: Plane I - from onset of automatic respiration to cessation of eyeball movements Plane II - from cessation of eyeball movements to beginning of paralysis of intercostal muscles Plane III - from beginning to completion of intercostal muscle paralysis. Plane IV - from complete intercostal paralysis to diaphragmatic paralysis Ref: Miller's anesthesia 8th edition Ref: Morgan & Mikhail's clinical anesthesiology 6e