Blood pressure Flashcards
What are medical indications to measure blood pressure?
- routine screening in geriatric cats
- when clinical signs of hypertension are noted (target organ damage)
- when a disease is present that causes hypertension
- critical care monitoring esp anesthesia
What are the two categories of high blood pressure?
secondary to disease (e.g. renal disease)
2. primary (idiopathic) hypertension
What animals get primary hypertension
certain populations of cats
What are clinical signs of hypertension? (TOD)
- retinal lesions
- heart murmurs–heart must work harder, hypertrophy,deformation of valves etc
- neurologic signs–e.g. in cat random yowling etc
What are three diseases that can cause hypertension in cat?
renal disease
hyperthyroidism
adrenal masses
What is the hypertension risk of TOD based on blood pressure
- mild 150-159/95-99
- moderate 190-179/100-119
- severe >180/120
Why does hypertension affect the eye?
The retinal arteries are autoregulatory but that is ment to be short term. they stay constricted and downstream the vessels become compromized and leaky, may see tears and hemorrhage–starving parts of themselves basically.
The choroidal vessels do not do that but at certain level they can have a high enough pressure that they become leaky
What can hypertension lead to in the eye?
hypertensive retinopathy
hypertensive choroidopathy
hypertensive optic neuropathy
(lesions like tortuous vessels, bulloid? detachement, serous detachment of retina)
What effect does hypertension have on the CNS?
Above 150mmHg, autoregulatory mechanisms start to fail, start to see edema and hemorrhage and thus increase in intracranial pressure: behavior change, salivation, seizure, cranial nerve deficits, visual deficits, coma, abnormal vocalization, lead pressing etc
What happens to blood pressure when you have a brain tumor?
your blood pressure increases but usually bradycardic. Whereas in animals with high blood pressure rather than primary brain lesion the hear rate is usually normal
What happens to heart with hypertension?
systemic vascular constriction causes concentric hypertrophy. That means thicker heart muscle, less well perfused, more susceptible to catecholamines, ischemic injury. Can result in mumurs, gallops, arrythmias, increased R wave amplitude, left anterior fasicular block
What are differentials for a cat with a murmur?
- hypertension
- hyperthyroidism
- hypertrophic cardiomyopathy
How do you test the cause of a cat with a murmur?
test thyroid levels
take blood pressure
what is age? young to middle age cats get hypertrophic cardiomyopathy so if older more likely to be hypertension.
What should you think if see undulating aorta in a cat?
may have hypertension. can also occur in normal cats?
What are diseases that cause hypertension?
- renal disease (CRF, glomerular disease-addisons in cat, glomerulonephritis in dog)
- endocrine disease–hyperthyroidism (cushings, diabetes mild), pheochromocytoma
What is it important to ID hypertension with renal disease?
hypertension makes renal disease occur more quickly
What is a large cause of renal failure in dog where there can be significant hypertension?
glomerulonephritis
Why would you be worried in an animal under anesthesia with bradycardia?
may be hypotensive. CO=HRxSV
BP=COxTPR
IF an animal under anesthesia had bradycardia but a normal blood pressure, would you treat with atropine?
no because the animal has already compensated to keep blood pressure normal so not necessary to treat
Why can’t blood pressure measurement replace a physical exam?
could have ok blood pressure but poor perfusion so should be checking extremities! but low blood pressure DOEs indicate a problem
What are the characteristics of Doppler?
crap according to him
Can measure systolic, not diastolic. detects motion of red cells. Not that accurate. Doppler is supposed to measure systolic but they underestimate it and so are closer to mean. A lot of work for an awake animal. Restraint makes the animal stressed. Affordable. Audible signal–if not much help with sx. But very user dependent.
What are the characteristics of oscillometric units?
detect wall motion (or any motion e.g. shivering, or weightbearing!)
above systolic minor oscilations
Below systolic but above MAP the oscillations increase in size until MAP. Calculate diastolic.
Clinically relevant: systolic, diastolic and MAP. Possible to do with the owner
What is the most indicative of whether will have issues due to blood pressure?
pulse pressure, that is determined by systolic and diastolic
What is an issue with oscillometric blood pressure measurements?
cuff placement
works less well on high and low pressures
hard to use in cats
old technology, built for humans
What are pros of oscillometric?
systolic and diastolic, more appropriate for screening, can do with owner
What are the characteristics of HDO?
superior processor for oscillometric measurement–faster “real time” processing. Can use to measure BP in awake cat.
What are the big advantages of the HDO?
Works at higher and lower blood pressure and faster heart rates (e.g. ferret) and can attach to a laptop and see what the machine is seeing–check for artifact.
Why do not have to do multiple readings and averaging with HDO like people try to do with oscillometry?
Because you can see quickly if there is a lot of artifact or whether it is a good reading that you can use. Can’t do that with oscillometric
What is a good way to get around the “white coat” effect?
in home measurements with HDO
What are the characteristics of direct arterial pressure measurement?
- painful-may increase BP
- god for anesthesia monitoring in critical patients
- gold standard
- hemorrhage possible
- not for routine
- direct tip catheter, fluid filled external transducer
What happens if your cuff is too large?
artificially low blood pressure
What happens if your cuff is too small?
artificially high level
How many BP measurements should you take ?
5-7
What factors can you do to avoid white coat effect?
- have owner there
- let patient get used to room
- do before physical, blood draws
- quiet part of hospital
- take time
- watch pressure if doppler
- measure at home
What has the most impact on blood pressure (routine procedures?)
rectal temp
blood draw
What should be included in your protocol for BP measurement?
- same machine
- who is going to measure
- where to measure
- how to avoid patient stress
What dog breeds have higher blood pressure?
sight hounds
Do males or females have higher blood pressure?
males
What is the average PB for dogs in general, what is the average of sight hounds?
130/70
150/80
