Week 5 Nursing Flashcards
Neurological Health History Interview
Focus of History
▪ When?
▪ What does it feel like?
▪ Witnessed?
▪ Mechanism of injury?
▪ How often?
▪ Associated symptoms?
▪ Medications?
▪ Bowel and bladder control?
What is Consciousness?
▪ Consciousness is your individual awareness of your unique thoughts, memories, feelings, sensations, and environments
▪ Consciousness has biological and social purposes: Process
information, choose actions, set priorities, learn and adapt to new information, make decisions
Regulating Consciousness
Three large areas of the brain are involved in consciousness:
1. The reticular formation, whose activity level influences the
states of alertness, wakefulness, and sleep
2. The thalamus, which sorts the information from the rest of
the body and routes it to other parts of the brain
3. The cortex, which is of crucial importance for all forms of
perception and all control of voluntary movements
Altered Level of Consciousness
Altered levels of consciousness may be caused by medical
or mental conditions that impair or change awareness.
▪ A depressed level of consciousness is a common finding
in acute illness and disease
▪ It can occur due to intracranial disease or as a result of a
systemic insult:
– Hypoxia, hypotension, hypoglycaemia, hepatic encephalopathy,
renal failure and hypovolaemia
▪ Be concerned if you observe:
– Pupillary changes, behavioural changes, limitations in movement
or alterations in sensation or a GCS score fall ≥ 2 points.
Level of Consciousness
Most important aspect of a neurological assessment
▪ Conscious level deteriorates before any other neurological change is noted and is often subtle
▪ Most widely recognised assessment tool of level of consciousness is the Glasgow Coma Scale (GCS)
▪ A rapid assessment tool is AVPU
A= alert
V= response to voice
P= response to pain
U= unresponsive
Glasgow Coma Scale
▪ Developed in 1974 - Updated in 2014
▪ Used as a way to consistently communicate about the level of consciousness of patient with neurological injury
▪ Findings from the scale are used to guide decision making and monitor trends of responsiveness
Pupillary Function
▪ Pupils are usually round in shape and in the centre of the eye.
▪ Inspect pupils for shape, symmetry and reaction to light.
▪ Parasympathetic control of the pupil occurs with the
oculomotor nerve (CN III).
– In response to light the pupil constricts in size.
▪ Normal difference of up to 1mm between the pupils.
Dilated Pupils
▪ Caused by alcohol, atropine, some
recreational drugs and extreme stress.
Constricted Pupils
▪ Caused by opioid overdose, lower brain stem compression or damage to the PONS.
Neurological Deterioration in Vital Signs
▪ Hypotension
– Rarely occurs except as a terminal event.
▪ Hypertension
– Commonly occurs with an intracranial injury.
▪ Dysrhythmias
– Occurs as a result of changes in intracranial pressure.
▪ Tachypnoea
– Rapid respirations that are irregular in pattern.
▪ Temperature
– Alterations to thermoregulation.
▪ Hypoxia
– Reduced level of Oxygen in tissue
Respiratory Patterns
▪ Changes in respiratory patterns assist in identifying the
level of brainstem dysfunction or injury.
▪ Abnormal respiratory patterns include:
– Cheyne-stokes breathing
– Central neurogenic hyperventilation
– Apneusis
– Cluster breathing
– Ataxic breathing
– Bradypnoea
– Tachypnoea
▪ Changes in breathing patterns may only occur after
significant neurological insult or injury.
Stroke
▪ A stroke happens when the blood supply to the brain is interrupted due to a clot or a haemorrhage.
– Ischaemic
– Haemorrhagic
– Transient ischaemic attack (TIA)
▪ Blood contains oxygen and glucose which are essential for neurological functioning.
▪ Brain cells which do not receive enough oxygen and glucose die which results in the signs of a stroke.
Physiology of Pain
▪ There are four (4) fundamental processes involved in nociception, the process by which an individual becomes aware of pain:
▪ Transduction
– The changing of noxious stimuli in sensory nerves to energy
▪ Transmission
– Movement of the impulse from the site of origin to the brain
▪ Perception
– Developing conscious awareness of the pain
▪ Modulation
– The inhibition of pain impulse transmission and awareness
Transduction of Pain
▪ Damaged tissues and cells release various sensitising substances to initiate the pain physiology process:
– Prostaglandins (PG)
– Bradykinin (BK)
– Serotonin (5-HT)
– Substance P (SP)
– Histamine (H)
▪ Tissue damage can occur due to an inadequate blood supply, direct trauma and chemical insult.
▪ Sensitising substances activate nociceptors and prepare their membranes for movement of electrical impulses.
Transmission of Pain
▪ Cutaneous nerve transmissions travels through a reflex arc.
▪ Impulse travels to the brain at a rate of 90 meters per second.
