A drainage system for use in the drainage of ventricles of a patient's brain or of the patient's lumbar region and which is connected to a catheter inserted in either the ventricles or lumbar region and secured to the patient, the system including tubing from the catheter, a four-way stopcock inserted into the tubing followed by a Y-connector providing a needle-less sampling site, and a one-way valve, a length of flexible tubing leading from the one-way valve to a burette clamped within a sliding panel mounted on a support panel, suspension means for the support panel onto an IV pole, said sliding panel being in frictional contact with the support panel so as to remain in adjusted position on the support panel, and a drainage bag connected to the bottom of said burette to receive the collected fluid from the burette after it is measured. A four-way high flow stopcock is positioned between the burette and drainage bag, and the support panel is provided with two pairs of keyhole slots vertically spaced thereon for ease of replacement of a full drainage bag with an empty drainage bag. Also, a combination bubble level and measuring tape is provided with bent end on the extendable tape for connection to one of a pair of slits in the support panel for ease of system leveling by personnel in surgery.