This study was an interventional study. After approval the project, all patients candidate for surgery referred to academic hospitals affiliated to Babol University of Medical Sciences and spinal anesthesia was done for them, considered as the study population. All of the referal patients donot have criteria for arriving to our investigation so ,three hundred patients were recruited in the study by simple randomized method. Those with a contraindication of LP were excluded. Five to 7 mlit/kg crystalloid were prescribed before spinal anesthesia. Anesthesia was done in semisitting position, in L3 to S1 intraspinal space with a size 25 needle (G25). Then patient goes as supine position and after reaching to a sufficient anesthesia level, operation would be started. Dexamethasone 8 miligrams, Midasolam 1-2 miligrams or Fentanyle 1.5-2 micrograms per body weight were used after spinal anesthesia regards to the age and type of surgery. CSF fluid situation, intraspinal space used for spinal anesthesia, type and amount of infused drugs into intratecal space, liquid supplementation and type of surgery were recorded in a checklist. During the spinal anesthesia, vital signs were checked for all and recorded. All patients were followed up to a week after discharge.