Vascular Hypertension Flashcards
How is Vascualar hypertension defined?
What is the incidence?
- Sustained diastolic of 90 mmHg or above
- Sustained systolic of 140 mmHg or above
- Average of 3 different measurements
- Incidence: 30% of general public
What are the systolic and diastolic limits for:
Normal BP
prehypertension
Stage 1 hypertension
Stage 2 HTN
(chart)
What is hypertension the most important risk factor in?
- CAD
- CVA
- Cardiac hypertrophy
- renal failure
- aortic dissection
What are the causes of HTN?
- 90% of HTN is idiopathic primary
- 5-10% is mostly secondary to renal disease
What is so bad about HTN?
- leads to increased myocardial wall tension which then leads to Left ventricular hypertrophy
- LV hypertrophy then leads to increased myocardial oxygen demand which leads to coronary insufficiency
- If this goes on long enough it leads to heart failure
How do we regulate BP?
- BP = CO x PVR
- CO is impacted by
- flood volume
- cardiac factors- enlarged muscle, etc.
- PVR is impacted by:
- humoral factors- constrictors, dilators (genetics predispose pple to have more of one or the other)
- neural factors
- local release of constrictors or dilators
What are the different types of hypertension?
- Essential hypertension- 95%
- Secondary hypertension- 5%
- renal
- endocrine
- CV
- neurologic
What are the risk factors of Essential HTN?
- Genetic
- polygenic and heterogenous
- polymorphism is lots of different genes
- Environmental
- stress
- obesity
- smoking
- salt consumption (really need a genetic predispostion along with a high Na diet)
- sedentary life style
What are some of the pathophysiological causes of Primary HTN?
- Increased SNS activity in response to stress
- overproduction of Na retaining hormones and vasoconstrictors
- Underproduction of vasodilators (NO, prostaglandins)
- Increase Na intake/ Na retention
- inadequate intake of Ca and K
- DM
- obesity
How do diretics act as effective antihypertensives?
by promoting Na excretion
*Also, Na restricted diet will help decrease BP
What are the pathologies of secondary hypertension?
(6)
- Oral contraceptives
- renal parenchymal disease
- Renin-secreting tumors
- primary aldosteronism
- cushing’s syndrome
- pheochromocytoma
What are some treatments for hypertension?
- Drugs- possibly combination of two for Stage 2 HTN
- Diuretics
- Ca channel blockers
- ACE inhibitors
- Beta blockers
- Angiotensin receptor blockers
- Non-Drug
- lifestyle changes- wt loss, smoking cessation, physical activity
- Na restriction, diets
- decrease ETOH
- relaxation techniques
Which BP meds would you used for different diseases? (chart)
Previous MI
Heart failure
CAD
DM
CKD
Recurrent stroke prevention
What is the definition of a hypertensive crisis?
How is it treated?
- Sudden increase in diastolic BP above 130 mmHG due to activation of RAAS
- Treatment:
- Prompt but controlled reduction with NTP
- 0.5-10 mcg/kg/min IV
- Monitor UOP and arterial BP
- Decrease DBP to 100-110 over 30 min-1 hour
- Prompt but controlled reduction with NTP
What other meds (and doses) can you give to treat a hypertensive crisis?
- Nitroprusside 0.5-10 mcg/kg/min
- drug of choice; short DOA
- Nitroglycerin 5-200 mcg/min
- Labetalol 40-80 mg q 10 min
- Esmolol 50-300 mcg/kg/min
What do you need to consider regarding the anesthesia management of essential HTN?
- Is it controlled or uncontrolled?
- Is the surgery emergent or elective?
- Is there evidence of end organ damage?
- angina
- CHF
- CVA
- Renal insufficiency
- PVD
- What is their medication regimen?
If your patient has poorly controlled HTN, what should you expect during induction, maintenance, and Post-op managment?
- Induction
- Exaggerated systemic blood pressure changes
- try to limit time of DVL and SNS response
- Maintenance:
- monitor for myocardial ischemia
- monitor end-organ function (art line, foley)
- adjust dept of anesthesia to minimize wide shifts in hemodynamics
- Post op
- goal to minimize SNS response to surgical pain and N/V
How can you minimize SNS stimulation with DVL?
- Any induction agent is appropriate except Ketamine
- Lidocaine 1-1.5 mg/kg
- Topical Lidocaine 2-4% (5 ml)
- Opioids
- Volatile agents
How can you be prepared to adjust dept of anesthesia during maintenance to accomodate wide hemodynamic shifts?
- Choose an IA that is easily adjusted- Sevo or Des
- d/t low B/G coefficient
- Des can cause increased HR d/t SNS outflow when put on fast
- use a balanced technique
- have ephedrine, Phenylephrine readily available
- consder phenylephrine gtt if unable to get adequate dept of anesthesia
- **Cardiac IA of choice is usually Isoflurane
How do you treat intraoperative hypertension?
- It is usually caused by pain!
- incidence is higher in pts with essential HTN
- treatment
- narcotics- esp if pain is obvious
- IA’s
- BB
- NTG
- nipride
How do you treat intraoperative hypotension?
- Treatment
- decrease anesthetic depth
- Fluids or blood
- Sympathomimetics
- Check rhythm–> is it junctional?
- maintain normocapnia
- avoid high concentrations of IA’s
- **hypotension is worse for pts who are normally hypertensive b/c they are not used to having low BPS
How would you want to monitor pts with HTN?
- 5 leak EKG
- A-line, CVP, PA cath if the surgery is extensive and ventricular dysfunction
- TEE
How should you emerge a pt with HTN?
- Controlled emergence
- minimize sympathetic outflow
- use narcotics
- lidocaine
- labetalol, esmolol, NTG
- Deep extubation
How can you control post-op hypertension?
- First ensure pain is adequately controlled
- If yes, then treat HTN with:
- Hydralazine 2.5-10 mg IV q 20-30 min
- Labetalol 5-20 mg IV q10 min
- Nipride 0.5-10 mcg/kg/min
