Assessment of the Patient Flashcards
What % of head trauma cases are polytrauma?
60%
Define head trauma as a primary injury?
Immediate injury, as a result of the mechanical damage.
Define head trauma as a secondary injury?
Which come minutes to days after the primary injury.
Contusions, haematomas and lacerations are primary or secondary?
Prima
The cranial vault is a rigid structure containing (3)
Brain tissue
Blood
Cerebrospinal fluid
How does ICP increase?
An increase in the volume of any one of any of brain tissue, blood or CSF without a reduction in volume of one of the others
What defines the relationship between contents of the crania and ICP?
Monro-Kellie Doctrine.
In normal patients, as intracranial volume increases, the increase in ICP is initially prevented by a process of
isobaric spatial compensation
What does isobaric spatial compensation involve?
This involves initial redistribution of cerebrospinal fluid (CSF) from the cranial vault to the spinal compartment.
Once the process of isobaric spatial compensation is exhausted, what is the 2ry mechanism that commences?
blood also being redistributed away from the cranial vault.
What happens once isobaric spatial compensation and 2ry mechanism exhausted?
further compensation is limited, and continuing increases in intracranial volume (ICV) will result in ICP increasing sharply.
Maintenance of cerebral function is dependent on
Adequate blood being delivered to the brain
What does adequate blood being delivered to the brain rely on?
Adequate cerebral perfusion pressure (CPP).
Define cerebral perfusion pressure (CPP).
Include equation
the difference between mean arterial pressure (MAP) and ICP or cerebral venous pressure (CVP), whichever is greater.
CPP = MAP – ICP or CVP (whichever is the highest)
If ICP increase, what also needs to increase to maintain cerebral perfusion?
MAP
How does marked elevation in MAP lead to bradycardia?
Trigger a baroreceptor response, resulting in a subsequent bradycardia
What is elevated MAP -> baroreceptor -> bradycardia known as?
Cushing response.
With a head trauma, what extra-neurological lesions might be? (7)
Vascular
Respiratory
Cardiac
Abdominal
Musculoskeletal
Skin
Connective tissue.
With a head trauma; What other assessments or basic diagnostics might you wish to perform prior to neurological assessment? (3)
Bloods; PVV, total solids, glucose, electrolyte
Imaging of abdo/thorax - bladder and thorax injuries
USG
The aim of the neurological assessment with a head trauma?
Localize lesion
Determine prognosis
What to evaluate on initial neuro assessment? (5)
Consciousness
Breathing pattern
Pupil size
Ocular position
Movement and motor response of ocular
What scale to use to assess prognosis and monitor progress?
“Modified Glasgow Coma Scale”
How often to repeat the “Modified Glasgow Coma Scale”?
30-60 mins
What should the initial exam determine location wise following head trauma?
supratentorial (mostly affecting the forebrain) or infratentorial (mostly affecting cerebellum and caudal brainstem).
Which aspect of the brain is the following located to:
Seizures
Supra tentorial
Define supra tentorial?
Mostly affecting forebrain
Define infratentorial
Mostly affecting cerebellum and caudal brainstem
Which aspect of the brain is the following located to:
Nystagmus physiological can be decrease/absent
Infratentorial
Which aspect of the brain is the following located to:
Menace response can be altered
Supratentorial
Which aspect of the brain is the following located to:
Response to nasal stimulation can be altered
Supra tentorial
Which aspect of the brain is the following located to:
Palpebral reflex can be altered
Infra tentorial
Which aspect of the brain is the following located to:
PLRS can be altered/anisocira can be present
Infra tentorial
Signs seen which would indicate supra tentorial? (3)
Seizures are common
Menace response can be altered
Response to nasal stimulation can be altered.
Signs seen which would indicate infra tentorial? (3)
Palpebral reflex can be altered
Nystagmus physiological can be decreased/absent or pathological nystagmus present
PLRs can be altered / anisocoria can be present.
What is the most reliable empiric measure of impaired cerebral function?
Level of consciousness
What posture is associated with a poor prognosis?
comatose patient in decerebrate rigidity
Which 2 ocular presentations are associated with a guarded prognosis?
Anisocoria
Miosis
What is anisocoria associated with lesion wise?
Unilateral compression/contusion
Increased ICP
What is miosis associated with following a head trauma?
Brainstem compression
What trauma is non responsive mydriasis associated with?
Compression/contusion bilateral
What is the prognosis with non responsive mydriasis?
Poor
