ORTHOSTATIC HYPOTENSION + BED REST Flashcards
Orthostatic hypotension
An atypical drop in blood pressure when a person stands up from a laid down or seated position
- gravity causes arterial pressure to drop
- less oxygen to the brain
- dizziness
- fainting
- increase risk of falls
Baroreceptor Reflex
- baroreceptors located in aortic and carotid arteries sense a decrease in blood pressure
- communicates with the medulla to enforce a reaction where blood vessels constrict and heart rate increases to increase blood pressure
Orthostatic Hypotension - causes
-
Hypovolemia - reduced volume in the vascular department
- inadequate intake
- excessive urination
- use of diuretics
- excessive sweating
-
Increased age
- decreases in compensatory mechanisms like the baroreceptor reflex
- reduce BV
- reduced skeletal pump function
- systolic dysfunction
-
Immobilisation
- decreased plasma volume (3 days of bedrest)
- decreased muscle tone (2 weeks of bedrest)
- therefore decreased blood return = decrease preload
-
Nervous system complications
- peripheral neuropathy
- spinal cord injury
- cerebral vascular accidents (stroke)
- impair NS reflexes that regulate BP
OH - symptoms
- dizziness
- fainting
- naseau
- loss of colour in face
- dazed gaze
mananging OH symptoms
- change of medication?
- If anemic - iron or Vitamin B12
- standing up slower - allow negative feedback mechanisms to kick in
- contract calf muscles whilst in a seated position - increased BF to the heart
- elevate head with pillows whilst sleeping
- prevent dehydration
- prevent vasodilation
- increase vascular volume
Role of physio
- Education
- Assessing and diagnosing patients
- Respiratory management
- Maintaining and progressing Range of Movement / Strength / Mobility
- Restoring movement and mobilising patients
- Communication / Referral
Orthostatic Intolerance
- The inability of the cardiopulmonary system to maintain blood pressure and adequate cerebral perfusion pressure against gravity
- Development of sings and symptoms during the upright standing
Symptoms
- Drop in systolic blood pressure / mean
arterial pressure - Heart rate & weak pulse
- Sweating, tremor, nausea
- Feeling faint, light headed or dizzy
- Beware of the patient who goes quiet
Effects of prolonged bedrest
Thromboembolic disease
- Increased venous stasis
- Increased risk of DVT, PE
Insulin resistance
- Increased resting blood glucose levels
- Increased total cholesterol and triglyceride levels
Microvascular dysfunction
- Vascular endothelium dysfunction
- Blunted hyperaemic response after 3-5/7 bed rest
- Increased systemic vascular resistance
Systemic inflammation
- Increased markers of low-grade inflammation TNFα and CRP after 14/7 rest in older
participants
- Reduced anti-inflammatory markers IL-6 with 14/7 rest in younger participants
Atelectasis (partial lung collapse)
- Lung compliance reduced with supine positioning
- Increases risk of pneumonia
Pressure ulcers
- Breakdown of skin at points of pressure
- Increased risk of cellulitis and osteomyelitis
effects of anaesthetic
Effects of anaesthetic
- sleepiness
- headache
- naseau/vomiting
- dizziness/feeling faint
- feeling cold/shivering
- temporary confusion and memory loss
Taking blood pressure
- Perform hand hygiene
-
Communicate with the patient and explain the procedure
- Does the patient have a preference of arm
- Ensure the cuff size is appropriate for the patient
-
Locate the patient’s brachial artery
- Inflate the cuff while palpating the brachial pulse
- When the brachial pulse can no longer be felt, deflate the cuff
- Take note of the reading on the sphygmomanometer
- Place stethoscope bell over brachial artery
- Inflate the cuff to the pressure you recorded +20mmHg (180-200mmHg)
- Slowly deflate cuff by 2-3mmHg per second, listen for the Korotkoff sounds
- First Korotkoff sound = Systolic BP
- Last Korotkoff sound = Diastolic reading
