epidural space

(noun)

The space within the spinal canal formed by the surrounding vertebrae lying outside the dura mater, which encloses the arachnoid mater, subarachnoid space, the cerebrospinal fluid, and the spinal cord.

Related Terms

Examples of epidural space in the following topics:

  • Epidural Anesthesia

    • An epidural, or epidural anesthesia, is a form of regional anesthesia involving injection of drugs into the epidural space.
    • The term epidural is often short for epidural anesthesia, a form of regional anesthesia involving injection of drugs through a catheter placed into the epidural space.
    • The epidural space is the space inside the bony spinal canal, but outside of the spinal cord.
    • A spinal needle is then advanced into the epidural space .
    • The catheter is a fine plastic tube, through which anesthetics may be injected into the epidural space .

  • Overview of the Spinal Cord

    • The spinal cord, protected by the vertebral column, begins at the occipital bone and extends down to the space between the first and second lumbar vertebrae.
    • The space between the dura mater and the surrounding bone of the vertebrae is called the epidural space.
    • The epidural space is filled with adipose tissue and contains a network of blood vessels.
    • The space between the arachnoid and pia maters is called the subarachnoid space and is where the CSF is located.
    • This central region surrounds the central canal, which is an anatomic extension of the spaces in the brain known as the ventricles and like the ventricles, contains cerebrospinal fluid.

  • Analgesia: Relief from Pain

    • The term "epidural" is a simplified term that refers to the technique of epidural analgesia.
    • In this technique, a catheter is inserted 4-6cm into the epidural space (the outermost part of the spinal canal, outside the dura matter), allowing analgesics (typically opioids) and anesthetics to be injected directly into the nervous system.
    • As with intravenous (IV) needles, epidural catheters may be left inserted for several days so that multiple doses of medicine can be administered with only one puncture point.
    • Epidurals in the lumbar region are typically placed in the iliac crest, well below the terminus of the spinal cord.

  • Spinal Tap

    • A spinal needle is inserted between the lumbar vertebrae L3/L4 or L4/L5 and pushed into the subarachnoid space.
    • It can be treated by further bedrest, or by an epidural blood patch, where the patient's own blood is injected back into the site of leakage to form a clot and seal off the leak.
    • They include spinal or epidural bleeding and trauma to the spinal cord or spinal nerve roots resulting in weakness or loss of sensation, or even paraplegia.
    • The latter is exceedingly rare, since the level at which the spinal cord ends is several vertebral spaces above the proper location for a lumbar puncture.

  • Meninges

    • In the region of the brain, particularly, a large number of fine filaments called arachnoid trabeculae pass from the arachnoid through the subarachnoid space to blend with the tissue of the pia mater.
    • The subarachnoid space is the space that normally exists between the arachnoid and the pia mater, which is filled with cerebrospinal fluid.
    • When the dura mater and the arachnoid separate through injury or illness, the space between them is the subdural space.
    • An epidural hematoma similarly may arise after an accident or spontaneously.

  • Oxytocin and Childbirth

    • If an epidural is requested it is usually given in this phase.
    • Surgery is usually done while the woman is awake but anesthetized from the chest to the legs by epidural or spinal anesthesia.

  • Sinusitis

    • Sinusitis may extend to the central nervous system where it may cause cavernous sinus thrombosis, retrograde meningitis, and epidural, subdural, and brain abscesses.

  • Herniated (Slipped) Disc

    • An alternative treatment is the injection of cortisone into the spine adjacent to the suspected pain generator, a technique known as "epidural steroid injection. " In certain settings, however, these injections may result in serious complications.

  • Survival Needs

    • To sustain human life, certain physiological needs include air, water, food, shelter, sanitation, touch, sleep and personal space.
    • These are: air, water, food, shelter, sanitation, sleep, space, and touch.
    • Space: As humans, we require personal space.
    • In addition to the requirement for shelter, or suitable indoor living space, humans need outdoor space, to avoid overcrowding and chaos.

  • Pressure Changes During Pulmonary Ventilation

    • It is defined as $VA=(Tidal Volume-Dead Space Volume)* Respiratory Rate$
    • It is defined as $VD=DeadSpaceVolume*Respiratory Rate$.
    • This is most apparent in changes of the dead space volume.
    • Breathing through a snorkeling tube and having a pulmonary embolism both increase the amount of dead space volume (through anatomical versus alveolar dead space respectively), which will reduce alveolar ventilation.
    • Differentiate among the types of pulmonary ventilation: minute, alveolar, dead space