Loss of brain stem reflexes, including pupillary, corneal, gag, and swallowing
reflexes, is an ominous sign of approaching death.Monitoring Intracranial Pressure
Because clinical assessment is not always a reliable guide in recognizing increased ICP,
especially in comatose patients, monitoring of ICP and cerebral oxygenation is an
essential part of management (Hickey, 2003). ICP is monitored closely for continuous
elevation or significant increase over baseline. The trend of ICP measurements over
time is an important indication of the patient's underlying status. Vital signs are
assessed when an increase in ICP is noted.
Strict aseptic technique is used when handling any part of the monitoring system. The
insertion site is inspected for signs of infection. Temperature, pulse, and respirations
are closely monitored for systemic signs of infection. All connections and stopcocks are
checked for leaks, because even small leaks can distort pressure readings and lead to
infection.
When ICP is monitored with a fluid system, the transducer is calibrated at a particular
reference point, usually 2.5 cm (1 inch) above the ear with the patient in the supine
position; this point corresponds to the level of the foramen of Monro (Fig. 61-7). CSF
pressure readings depend on the patient's position. For subsequent pressure readings,
the head should be in the same position relative to the transducer. Fiberoptic catheters
are calibrated before insertion and do not require further referencing; they do not
require the head of the bed to be at a specific position to obtain an accurate reading.
Whenever technology is associated with patient management, the nurse must be certain
that the technological equipment is functioning properly. The most important concern,
however, must be the patient who is attached to the equipment. The patient and family
must be informed about the technology and the goals of its use. The patient's response
is monitored, and appropriate comfort measures are implemented to ensure that the
patient's stress is minimized.
ICP measurement is only one parameter; repeated neurologic checks and clinical
examinations remain important measures. Astute observation, comparison of findings
with previous observations, and interventions can assist in preventing life-threatening
ICP elevations.
Monitoring for Secondary Complications
The nurse also assesses for complications of increased ICP, including diabetes
insipidus and SIADH (see Chapters 14 and 42). Urine output should be monitored
closely. Diabetes insipidus requires fluid and electrolyte replacement, along with the
administration of vasopressin, to replace and slow the urine output. Serum electrolyte
levels are monitored for imbalances. SIADH requires fluid restriction and monitoring
of serum electrolyte levels.
Evaluation
Expected Patient Outcomes
Expected patient outcomes may include the following:
Maintains patent airway
Attains optimal breathing pattern
o Breathes in a regular pattern
o Attains or maintains arterial blood gas values within acceptable range
Demonstrates optimal cerebral tissue perfusion
o Increasingly oriented to time, place, and person