Go Lumbar (spinal) puncture

Spinal puncture

Spinal puncture (synonym: lumbar puncture, lumbar puncture) is an operation performed to extract the cerebrospinal fluid or to inject into the spinal canal medicinal or contrast agents . In diagnostic spinal puncture, fluid pressure, color, transparency, composition are investigated, biochemical and serological reactions are performed, or air is introduced during pneumoencephalography .

For diagnostic purposes, spinal puncture is performed in mental and nervous diseases, especially in meningitis, injuries of the brain and spinal cord , in vascular diseases, and, in particular, in brain tumors.

lumbar puncture
For therapeutic purposes, spinal puncture is performed to reduce the pressure of the cerebrospinal fluid during meningitis, open brain drainage, to release the cerebrospinal fluid from blood and decay products after brain and spinal cord surgery, as well as to inject drugs into the subarachnoid space.


Spinal puncture is recommended in the supine position of the patient on the left side. The patient bends his head to the chest, and his legs, bent at the knee and hip joints , leads to the stomach. The back of the patient should be the most bent arc. To give a bent position to the weak patients, the nurse puts her hands under the back of the head and knees of the patient and brings them closer, creating the desired position of the spine . The operative field in the lumbosacral region is treated with alcohol and a weak solution of iodine.

After the obligatory layer-by-layer anesthesia (3-4 ml of 1% solution of novocaine) of the soft tissues, a thin needle with mandrin is inserted into the spaces between the spinous processes of III and IV or IV and V and lumbar vertebrae, they pass into the subarachnoid space. Upon removal of the mandrel from the lumen of the needle, the cerebrospinal fluid begins to stand out. After measuring the pressure of the cerebrospinal fluid, it is collected in a sterile tube and urgently delivered to the laboratory. For diagnostic purposes, it is enough to withdraw 5-6 ml of liquid. If you suspect a tumor, an abscess, cysticercosis of the brain, a closed brain edema (see Hydrocephalus), you must take special care and remove no more than 2-3 ml of liquid in drops, partially removing the mandrin. The needle is removed along with mandrin, the injection site is smeared with an alcoholic solution of iodine and sealed with collodion. After a spinal puncture, the patient is placed on the stomach and the orderlies carry him on their hands from the gurney to the bed. The nurse should ensure that the patient for 2–3 hours lying in bed on his stomach, without a pillow, and later on his side. In order to avoid complications after spinal puncture, a patient is recommended a strict bed rest for at least 2-3 days.

Absolute contraindication to spinal puncture are purulent processes in the lumbosacral region.

After spinal puncture, sometimes headache, backache, nausea , rarely vomiting and meningeal symptoms may occur, in which it is advisable to prescribe hexamethylenetetramine ( hexamine ), analgesics, valerian preparations. These phenomena usually disappear in 3-4 days. In patients with brain tumors, more terrible complications can be observed: tonic convulsions , unconsciousness, respiratory disorders and cardiovascular activity caused by the displacement of the brain and the restriction of its trunk. It is necessary to raise the foot end of the bed 40-50 cm and urgently call the doctor on duty.


Lumbar puncture (punctio lumbalis; synonym: spinal puncture, lumbar puncture) is an operation performed to extract the cerebrospinal fluid or to introduce medicinal or contrast agents into the spinal canal. Diagnostic lumbar puncture is produced to study the pressure, color, transparency and composition of the cerebrospinal fluid, as well as to introduce into the subarachnoid space of contrast agents in the production of myelography and pneumoencephalography. For therapeutic purposes, lumbar puncture is performed to temporarily reduce spinal pressure, extract a significant amount of cerebrospinal fluid (up to 10-30 ml) with meningitis and cerebrospinal fluid containing large amounts of blood and decomposition products after brain operations, as well as for introduction into the subarachnical space of medicinal substances.

Lumbar puncture is contraindicated in case of danger of occurrence or enhancement of the tentorial hernial wedge of the temporal lobe of the brain and infringement of the tonsils in the large occipital foramen. These phenomena are observed in subtentorial tumors and abscesses of the brain and in the supratentorial location of them in cases where there are symptoms of brain dislocation. Lumbar puncture in these patients is carried out only with absolute indications in a neurosurgical hospital, since quite often after a puncture there are urgent indications for surgical intervention. When there is a danger of brain dislocation, only a small amount of cerebrospinal fluid (2–3 ml) needed for the study is extracted. At the same time, in order to slowly release the liquid, the mandrins are only partially removed from the needle lumen.

Technique lumbar puncture . The patient is placed on the side with legs sharply bent at the hip and knee joints, with a slightly bent head located in the same horizontal plane with the torso. After treating the skin over a wide area with gasoline, alcohol and iodine, the doctor probes the spinous processes and marks the puncture site. Usually lumbar puncture is performed in the gap between the spinous processes of the LIII and LIV, which are located approximately on the horizontal line connecting the crests of the iliac bones. At the puncture site, strictly in the sagittal plane, a thin needle is injected intracutaneously and subcutaneously, up to the bone, 1–3 ml of a 0.5% solution of novocaine, for fear of hitting the needle and introducing the solution into the subarachnoid space. After that, the needle is removed and with the help of a special needle with a thickness of 0.5-1 mm, a length of 9-12 cm, the sharp end of which is beveled at a 45 ° angle, puncture of the sheath space is made. The needle lumen is closed by a well-adjacent and easily sliding mandrel, the inner segment of which exactly corresponds to the lumen of the inner end of the needle. Outside, the mandrin is provided with a rough hat, which can be easily grasped when removing and introducing the mandrel. During puncture, the needle is directed strictly in the sagittal plane and slightly upward so that, after passing through the skin and subcutaneous tissue, the yellow ligament, epidural fatty tissue, the solid and arachnoid brain membranes, fall into the. subshell space. At the time of the puncture of the dura mater, the doctor has a peculiar sensation of "falling the needle." Then the needle is pushed forward another 1-2 mm and the mandrin is removed, after which the spinal fluid flows out.

Thin crossbars, located in the subarachnoid space, can adhere to the needle lumen, thereby making it difficult or stopping the outflow of cerebrospinal fluid. When the needle is rotated 30–180 °, slightly moving it forward or backward, this obstacle may disappear and fluid begins to flow out of the needle faster.

If a bloody cerebrospinal fluid begins to flow from the needle as a result of damage to the blood vessels at the time of the puncture production, and not subarachnoid hemorrhage, in the absence of contraindications, you should continue to release the fluid. At the same time, a clear cerebrospinal fluid, which is suitable for research, soon begins to flow out.

For diagnostic purposes, the extraction of 2-3 ml of cerebrospinal fluid (for basic research of its composition) is shown. If necessary, other studies (Wasserman reaction, etc.) should be extracted 5-8 ml of liquid. To measure the pressure of the cerebrospinal fluid, a manometric tube is widely used - a glass tube bent at a right angle with a diameter of 1 mm and two elbows - a long vertical graduated and a short horizontal one connected by a hollow elastic to a metal cannula. The free end of the cannula is introduced into the external lumen of the puncture needle, from which spinal fluid flows, which goes to the horizontal and vertical knee of the measuring tube. With high fluid pressure, exceeding the length of the vertical knee, the latter is extended by an additional tube, connecting rubber tube with a vertical knee.

Measurement of the pressure of the cerebrospinal fluid, as a rule, is performed in the position of the patient lying down. If it is normal in the lumbar spine, when examining the prone position, the pressure fluctuates between 100–180 mm of water. Art., then in the study in a sitting position, it is due to hydrostatic pressure increases to 250-300 mm.