Page 266 - Critical Care Nursing Demystified

Chapter 5 CARE OF THE PATIENT WITH NEUROLOGICAL NEEDS 251

Interpreting Test Results
Usually diagnosed via CAT scan.

Prognosis
Glioblastomas are clinically very aggressive with a rare survival rate of no greater
than 2 years.
Benign, well-defined brain lesions are usually removed surgically and suc-
cessfully. Invasive, poorly defined brain tumors are not totally 100% removed
via craniotomy. However, surgery will decrease or debulk the tumor, which in
turn will reduce pressure on the surrounding structures and slow the tumor
growth process.
Radiation may be used to treat tumors of the brainstem, thalamus, and hypo-
thalamus instead of surgery, because if surgery is attempted in these difficult-
to-reach areas, severe neurologic deficits can result. The goal of radiation
therapy is to slow down or destroy the growth of tumor cells without damaging
normal brain tissue.
Stereotaxic radiation is a process in which radioactive loaded catheters are
implanted into the tumor bed as a form of radiosurgery. Intracranial catheter
placement is done in the operating room and the patient stays overnight in the Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
critical care unit. The following day, a single high dose of ionizing radiation, or
radionuclide seed implantation, is directed via a Gamma Knife toward a small,
well-defined brain lesion. A Gamma Knife is an external high-energy photon
beam that is directed from a linear accelerator.
Radiosurgery is performed under local anesthesia and without a surgical inci-
sion. As such, it is a good form of alternative treatment for the elderly, the
medically challenged and infirm, and for those who refuse microsurgical
removal.
Steroids, as described previously, are used to eliminate cerebral edema asso-
ciated with brain tumors pre- and postoperatively.
Apparently, regional hyperthermia is another considered avenue of treat-
ment to destroy brain tumor cells. The inner regions of many brain tumors are
hypoxic, have an acidic pH and poor blood flow, making them ultrasensitive to
the benefits of hyperthermia.

Chemotherapy
It is thought that the benefits of chemotherapy are in question because many
of the drugs are unable to cross the blood-brain barrier. Therefore, the brain
tumor mass might not be 100% sensitive to specific chemotherapeutic agents.