hypotension Flashcards
what is considered hypotension
<90/60
pathophys of hypotension
- Hypotension reduces blood flow
- Decreasing oxygen delivery to organs and tissues
- Causing cellular damage and dysfunction.
When oxygen delivery is insufficient to support tissue metabolic requirements, a person is said to be in what state?
circulatory shock
Arterial pressure is determined by:
(3)
1) cardiac output
2) venous pressure
3) systemic vascular resistance
Any reduction in these variables can lead to hypotension
causes of hypotension
- cardiogenic
- Acute coronary syndrome
- Arrhythmias
- Cardiomyopathy
- Congestive heart failure
- Valvulopathy
- Pulmonary embolism
- Pulmonary hypertension
- Cardiac tamponade
- Tension pneumothorax - hypovolemia
- Hemorrhage
- Dehydration
- Dialysis - orthostatic
- sepsis
- endocrinologic
- Adrenal insufficiency
- Diabetes
- Hypothyroidism - vascular
- Aortic dissection or rupture
- Peripheral vascular dz
- Pulmonary embolism - drugs
- Alcohol
- Anesthesia
- Antidepressants
- Antihypertensives
- Antipsychotics
- Anxiolytics
- General anesthesia
- Narcotics - neurogenic
- Age-related
- Medullary stroke
- Parkinsonism
- Postprandial
- Peripheral neuropathy
- Syphilis
- Vasomotor - Emotional, Micturition
Important Historical Information to ask for hypotension
Acute change in BP?
Precipitating events/symptoms?
Medications, including any recent changes?
Pre-existing medical conditions?
Are they symptomatic?
sx of hypotension
Depends on the patient, underlying cause, existing comorbidities, age, etc.
1. Lightheadedness, dizziness, HA
2. Syncope
3. Nausea
4. Confusion, Fatigue
5. chest pain
6. SOB
7. blurred vision
signs of hypotension
Bradycardia or Tachycardia
Skin - Pallor, Diaphoresis, Cool/clammy, Prolonged capillary refill
Altered LOC
Other signs depend on underlying mechanism
diagnostic testing/labs for hypotension
Testing should reflect your differential diagnosis!!
EKG
CBC, CMP, UA
Echocardiogram
Urine drug screen
CT head
management for hypotension
Depends on the underlying cause and patient presentation!
Typically, IV bolus of normal saline
Described as a drop in blood pressure upon standing, leading to symptoms of hypotension
Orthostasis or Postural hypotension
Orthostatics can occur due to ?
impairment of autonomic reflexes
volume depletion
Occurs more frequently in the elderly
criteria for orthostatic hypotension
- Drop of one or both of the following upon standing from a lying position:
- At least a 20 mmHg fall in SBP
- At least a 10 mmHg fall in DBP - Usually occurs within 2 to 5 minutes
However, delayed orthostasis may occur after 5 or even 10 minutes
Normal BP Response to Standing
Rapid decrease in venous return and cardiac output
Detected by baroreceptors in carotids
Standing stimulates sympathetic nervous system to: (3)
- Increase heart rate
- Increase peripheral vascular resistance
- Therefore, increasing cardiac output and limiting the actual drop in SBP
causes of orthostatics
- Prolonged lying or sitting
- Volume depletion
- Autonomic failure
- Neurodegenerative disease, such as Parkinson’s
- Neuropathies, as a result of DM, B12 deficiency, amyloidosis, sarcoidosis, Lyme disease
- Med SE - peripheral vasodilation, autonomic dysfunction, volume depletion
- Aging - Due to a decrease in baroreceptor sensitivity
- Adrenal insufficiency
- Cardiogenic
- CHF
- AS
- Arrhythmias
medications that cause orthostatics
- alpha-1 antagonists - terazosin, prazosin, doxazosin
- antiHTN - ACEi BB, clonidine
- diuetics - loops, HCTZD
- phosphodiesterase type 5 inhibitors - sildenafil, vardenafil
- antidepressants - TCA, trazodone, MAOi
- opioids - morphine, oxycodone, tramadol
sx of orthostatics
- Vary in severity
- Result of hypoperfusion to the brain - Classic symptoms include:
- Generalized weakness
- Dizziness or lightheadedness
- Blurry vision or darkening of the visual fields
- Syncope - Atypical presentations include:
- Fatigue, cognitive slowing and nausea
ways to evaluate orthostatics
- Bedside tilt test /Orthostatic BP measurement
- Formal tilt table test