소아의 실용적인 뇌압측정 방법

A practical mehod of estimating CSF pressure in children

Lumbar puncture has been to obtain CSF fluid for analysis and to measure CSF pressure, But, it is often difficult to measure CSF pressure in children. The flow of CSF through a spinal needle is described by equation: Flow = pressure/(needle constant X relative vescosity). Thus, the CSF flow rate(drops.30 sec) during lumbar puncture can be used to estimate CSF pressure. The CSF viscosity was approximately the same as the viscosity of 0.9% NaCI(relative viscosity = 1.02 at between 20℃ and 37℃). Based on this characterstics, normal saline was used to model CSF flow in vitro. The counting drops of CSF and 26℃ 0.9%NaCI for 30 sec through three spinal needle(22G, 21G, 20G, 3.5 inches) was measured at a given pressure (CmH2O). From January 1993 to jun 1993, the authers measured CSF pressure in a series of 80 children with CNS disease, leukemia, and other malignancy who admitted at dept. of pediatrics, college of medicine, Chungnam national university hospital, The summary of results were as follows: 1. The needles constants(mean + SD) for the 22-gauge 3.5 inch, 21- gauge 3.5 inch, and 20-gauge 3.5 inch spinal needles were 1.534 ± 0.066, 0.905 ± 0.038. 0.476 ± 0.013 CmH2O/Drop/30 sec, respectively. Above results were simply descrbed by the equation; P ≒ 1.5 X D, P ≒ 0.9 X D, P ≒ 0.5 X D(P = pressure CmH20, D = drops/ 30sec, G = gauge). 2. Dripping rate was related linearly to pressure for each size needle. 3. Bacause viscosity is temperature-dependent, flow rate through a spinal needle was increased at a high thmperature. Because the drops can bo counted while fluid is being collected, this method is more convenient tham manometric pressure measurement. Eliminating the use of manometer also simplifies the proceduer, reduces supply cost and time, and may avoid the problem of manometric pressure measurement such as pain or air bubbles.