There is a substantial amount of information that can be obtained just by retrieving and analyzing a patient's cerebral spinal fluid. From an evaluation of the white blood cells, glucose, and protein contained within the extracted cerebral spinal fluid, to the opening and closing pressure of the CSF itself, this pertinent data can certainly give medical professionals tremendous insight that can assist them towards the most accurate medical diagnosis possible. Performing many critical functions, such as cushioning the spinal cord and removing waste products from the brain, a patient's CSF just can't be removed with similar ease to retrieving a urine or stool specimen.

Similar to the invasive nature of blood collection, a spinal tap (otherwise known as a lumbar puncture) must be performed by a trained medical professional with upmost skill and adherence to sterile procedure in order to obtain both an opening and a closing CSF pressure reading. A spinal tap isn't typically done just to obtain a CSF pressure reading, however. Instead, the access created by the lumbar puncture needle can serve also as a route of entry for anesthesia in preparation for the labor birthing process in pregnant females. The CSF pressure reading, in conjunction with analysis of a patient's white blood cells, glucose, and protein, can be a very revealing indicator of the potential for the presence of diseases and conditions such as Guillain Barre syndrome, stroke, meningitis, multiple sclerosis, and tuberculosis.

Before proceeding with this InfoBarrel article, it is important to reiterate the fact that a spinal tap (or lumbar puncture) should only be done by a qualified medical professional, in a sterile environment.

Step #1

Familiarize Yourself with Normal Readings

In a medical setting, it is absolutely imperative that the medical professional conducting any surgery or procedure be highly trained and competent. Part of the fundamental competency required of anyone who will be performing a CSF spinal tap pressure reading is an understanding of the "normal" readings for the age group of the patient being assessed, along with, the implications of any clear deviations from those "normal" measurement values. The following "normal" values will be applicable to both the opening and closing cerebral spining fluid pressure readings:

  • a Newborn Baby: 50 mmH2O
  • a Young Child: 85 mmH2O
  • a Normal Adult: 65-200 mmH2O
  • an Extremely Obese Adult: 250 mmH2O

Any deviations in your obtained CSF pressure reading, from the "normals" above, can be an indication of various potential health disorders and conditions dependent up what the deviation is. For a patient who has a high CSF pressure reading, this could mean an increase in intracranial pressure and would require medical attention immediately in order to remedy. On the other end of the spectrum, a low CSF pressure reading could indicate tumors that are present of a patient's spinal cord.

Step #2

Gather Your Needed Supplies

Beyond your fundamental skill and competency, as with any medical procedure, you will have everything you need in place. Items needed include:

  • a Protective Eye Shield/ Eye Wear
  • a Pair of Sterile Gloves
  • a Protective Garment
  • a Sterile Manometer
  • a Sterile Stopcock

Both the sterile stopcock and the sterile manometer are designed specifically for use during a spinal tap. Because a spinal tap, and subsequent CSF measurement reading, are invasive procedures by nature, you can see the upmost importance of continually adhering to sterile technique throughout.

Step #3

Ensure Patient is Positioned Properly

Even though an opening and closing CSF pressure reading will be retrieved after the actual spinal tap lumbar puncture is performed, it is still important to know and understand what proper positioning of the patient for this procedure includes. In order to facilitate maximum exposure of the puncture area, during a CSF pressure reading the spinal tap needle will be in place while the patient's back is arched, with their knees as close to their chest as possible. The patient's head and upper spine will be bent forward, while their chin will approach where their chest and knees meet. Otherwise known as the lateral decubitus or relaxed fetal position, this position can be achieved either while the patient is lying on their side or while sitting up on a table. The position of the patient ultimately rests on the discretion and judgment of the trained medical professional who is conducting the spinal tap procedure. This position will be maintained by the patient throughout this procedure.