(2) A rapid respiratory rate can be caused if the intracranial pressure
continues to rise.
Respirations may be noisy.
(4) Kussmaul and Cheyne-Stokes patterns are often caused by the
metabolic causes of coma.
b. Blood Pressure. Over a period of time, note any changes in the patient's
blood pressure. The rise or fall of blood pressure can indicate changes in the patient's
condition or further injury.
(1) Rising blood pressure. Generally, blood pressure rises if intracranial
pressure rises. The systolic blood pressure in particular will rise. The effect is a
widening of pulse pressure (pulse pressure = systolic blood pressure minus diastolic
blood pressure). Therefore, if the patient's blood pressure rises without any medical
explanation, he may experience a rise in intracranial pressure.
(2) Falling blood pressure. If the patient's blood pressure is falling, he may
have an injury which has not been discovered and treated. The skull is a very small box
which is almost full of brain. Therefore, there is very little room in the skull for blood. If
the patient is in hypovolemic shock (shock produced by reduction of blood volume,
possible cause is hemorrhage), he is probably bleeding somewhere other than the
head. Look for a source of major hemorrhage somewhere else in the body.
c. Pulse. A change in pulse rate (either increasing or decreasing) may indicate
a serious problem. Note the following conditions:
(1) A slowing pulse will usually accompany the rise in blood pressure
observed in a patient with rising intracranial pressure. A continued rise in intracranial
pressure can produce tachycardia (abnormally fast heart beat), causing death.
A rising pulse rate may signal impending shock from bleeding elsewhere
in the body.
A rapid pulse without another cause is a serious sign.
(4) Bradycardia (an abnormally slow heartbeat) with hypertension suggests
a rapidly expanding hematoma.
d. General Examination. A general examination should include the following:
Check the scalp or skull for lacerations or fractures.