HTN Flashcards
Definition of HTN
BP > 140/90 on at least two occasions
Reading should be measured at least 1-2 weeks apart
__% of adults in the US have HTN
24%
Two types of HTN
1) Essential (95% of cases)
- Unknown cause (idiopathic)
- Strong genetic link (maybe related to inherited biochemical abnormalities)
- Associated with drinking, smoking, and OSA
2) Secondary (5% of cases)
- HTN with a known cause
- Renal problems is main cause
- Also endocrine, pregnancy, neurologic, drug induced, and OSA
Treatment for essential HTN
1) Lifestyle Modification
- Recommended for those without CV disease or end organ damage
2) Drug therapy
- Used in combo with lifestyle modification
- Drug therapy recommended for those with other existing comorbidities (DM, high cholesterol, angina, smoking) and/or have evidence of end-organ damage
Lifestyle modification involved for treating HTN
Weight loss Decrease ETOH intake Exercise Stop smoking Consume enough calcium and potassium Eat less sodium
Treatment of Secondary HTN
1) Treat the cause
- Usually d/t renal artery stenosis (kidneys perceive this as decreased blood flow and activate the RAAS) or primary aldosteronism
- So usually, require surgery
2) Drug therapy if not a candidate for surgery
Anesthesia considerations for patients on beta blockers
Rebound SNS stimulation (d/t upregulation of receptors)
Avoid in BBs in asthmatics, COPD, CHF, HB, Sick Sinus
Continue BB therapy
Anesthesia considerations for patients on methyldopa
A2 agonist used to treat HTN
Can cause rebound HTN and will decrease anesthetic requirements
Anesthesia considerations for patients on clonidine
A2 agonist
Rebound HTN and decrease in anesthetic requirements
Anesthesia considerations for patients on prazosin
A1 blocker
Compensatory vasoconstriction is blocked, so there may be an exaggerated drop in BP during spinal/epidural block
Anesthesia considerations for patients on hydralazine
Causes potassium influx and hyperpolarization
May cause angina in those with ischemic heart disease
Anesthesia considerations for patients on ACE inhibitors (prils)
Drop in BP and hemodynamic instability. This is one of the few meds that we may tell people to hold. Remember these people will be very dry.
Anesthesia considerations for patients on Angiotensin II blockers (artans)
BP drop with induction
Definition of hypertensive crisis
Acute DBP > 130
What can a hypertensive crisis cause?
Encephalopathy
SAH
CHF
Renal insufficiency