Stage of analgesia in anesthesia is -
Ans. is 'a' i.e., Stage-1 o Guedel described four stages of ether anesthesia known as Guedel stages.Stages of anesthesiao GAs cause an irregular descending depression of the CNS, i.e., higher functions are lost first and progressively lower area of the brain are involved. In the spinal cord, lower segments are affected earlier than upper segments. The vital centers located in the medulla are paralyzed the last as the depth of anesthesia increases,o Guedel described four stages of ether anesthesia dividing the Illrd stage into 4 planes. With faster-acting GAs these clear-cut stages are not seen now- days as induction with these agents is too fast.Stage 1 (Stage of analgesia): - It extends from beginning of anesthetic inhalation to the loss of consciousness.Stage 2 (Stage of delirium or excitement): - From the loss of consciousness to the beginning of regular respiration. There is roving eyeball (maximum movement of the eye). The pupil is partially dilated. Eyelash reflex is lost - the First reflex to be lost. However eyelid reflex remains present.Stage 3 (stage of surgical anesthesia): - From the beginning of regular respiration to cessation of spontaneous breathing. Most surgeries are done at this stage. It is divided into 4 planes : -Plane 1: From the beginning of regular respiration to the cessation of eye movement. There is a roving eyeball. Eyelid reflex is lost. This plane ends when eyeball becomes fixed. Pupil size is normal.Plane 2: From the cessation of eye movement to respiratory Paresis. The eyeball is fixed. There is a loss of corneal reflex. Pupil starts dilating ( 1/2 dilated).Plane 3: From respiratory paresis to respiratory paralysis. Pupil 3/4 dilated. Swallowing reflex and laryngeal reflexes are lost.Plane 4: Intercostal paralysis, there is only abdominal respiration. The pupil is fully dilated. Cardinal reflex (Cough reflex) is lost - the Last reflex to be lost.Lacrimation is present in plane II & III and absent in Plane III, IV.Stage 4 (stage of medullary paralysis): There are respiratory arrest and apnea. The pupil is fully dilated & fixed.
Stage-1
Stage-2
Stage-3
Stage-4