<prompt> All are stages of anaesthesia exceptAnalgesiaAllodyniaDeliriumSurgical anesthesia  <response>: Guedels 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: Millers anesthesia 8th edition Ref: Morgan Mikhails clinical anesthesiology 6e 