HTN

Question 1

Definition of HTN

Answer 1

BP > 140/90 on at least two occasions

Reading should be measured at least 1-2 weeks apart

Question 2

__% of adults in the US have HTN

Answer 2

24%

Question 3

Two types of HTN

Answer 3

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

Question 4

Treatment for essential HTN

Answer 4

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

Question 5

Lifestyle modification involved for treating HTN

Answer 5

Weight loss
Decrease ETOH intake
Exercise
Stop smoking
Consume enough calcium and potassium
Eat less sodium

Question 6

Treatment of Secondary HTN

Answer 6

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

Question 7

Anesthesia considerations for patients on beta blockers

Answer 7

Rebound SNS stimulation (d/t upregulation of receptors)
Avoid in BBs in asthmatics, COPD, CHF, HB, Sick Sinus
Continue BB therapy

Question 8

Anesthesia considerations for patients on methyldopa

Answer 8

A2 agonist used to treat HTN

Can cause rebound HTN and will decrease anesthetic requirements

Question 9

Anesthesia considerations for patients on clonidine

Answer 9

A2 agonist

Rebound HTN and decrease in anesthetic requirements

Question 10

Anesthesia considerations for patients on prazosin

Answer 10

A1 blocker

Compensatory vasoconstriction is blocked, so there may be an exaggerated drop in BP during spinal/epidural block

Question 11

Anesthesia considerations for patients on hydralazine

Answer 11

Causes potassium influx and hyperpolarization

May cause angina in those with ischemic heart disease

Question 12

Anesthesia considerations for patients on ACE inhibitors (prils)

Answer 12

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.

Question 13

Anesthesia considerations for patients on Angiotensin II blockers (artans)

Answer 13

BP drop with induction

Question 14

Definition of hypertensive crisis

Answer 14

Acute DBP > 130

Question 15

What can a hypertensive crisis cause?

Answer 15

Encephalopathy
SAH
CHF
Renal insufficiency

Question 16

How to treat hypertensive crisis?

Answer 16

Goal is to treat promptly, but gradually. Monitor BP reduction with an a-line.

• Decrease MAP by 20% during first 2 hours
• Gradually reduce BP to normal over the next 24-48 hours
• Achieve this with NTG or nipride** (use foley to measure UO, want to make sure the kidneys are still able to perfuse. Remember they are very sensitive to drops in BP! They can’t really autoregulate below a MAP of 80)

Question 17

Specific meds we can use to treat a hypertensive crisis

Answer 17

Place an a-line to closely monitor our reduction in BP!!

Nitroprusside 0.5-10 mcg/kg/min
- Drug of choice** (short DOA)

NTG 5-200 mcg/min
Labetalol 40-80mg Q 10 min
Esmolol 50-300 mcg/kg/min

Question 18

If you have a patient with HTN, you are wondering about these these

Answer 18

Do they keep their HTN under control?
What’s their drug regimen?
Do they have any evidence of end-organ damage? (Angina, CHF, Renal insufficiency, CVA, PVD, etc)

Question 19

Goals on induction for pts with HTN

Answer 19

Minimize SNS stimulation on DVL
- Do so with additional narcotic, lidocaine (topical or IV), and by increasing volatile agent

Lidocaine IV 1-1.5mg/kg
Lidocaine Topical 5cc of 2-4%

Question 20

Goals during maintenance for pts with HTN

Answer 20

It is common for patients with HTN to have wide hemodynamic shifts. Our goal, therefore, is to adjust anesthetic depth in a way that minimizes hemodynamic shifts. How the fuck do we do that?

• Choose an IA that can be easily adjusted (low BG coefficient like desflurane)
• Use a balanced technique like the pros
• Have phenylephrine and ephedrine available
• Consider neo gtt if unable to get adequate depth of anesthesia

Question 21

Post-op goals for pts with HTN

Answer 21

Minimize SNS stimulation from pain and N/V

Question 22

This induction agent is inappropriate for those with HTN

Answer 22

Ketamine

Question 23

How to treat intra-operative HTN

Answer 23

It’s usually due to pain!!

Opioids (if d/t pain)
IAs (will decrease SVR)
BBs
NTG
SNP (hang a drip if a longer case)

Question 24

Intra-op HTN is more common in patients with

Answer 24

Essential HTN

Question 25

Do patients with HTN handle HTN or hypotension better?

Answer 25

HTN! It’s what they’re used to!

Question 26

How to treat intra-op hypotension

Answer 26

• Reduce anesthetic depth (often caused by being too deep)
• Fluids
• Sympathomimetics (neo and ephedrine)
• Is their rhythm normal? If not, fix that shit.
• Make sure their CO2 is normal

Question 27

Monitoring used for those with HTN

Answer 27

5 Lead EKG**
If the patient has ventricular dysfunction and is having extensive surgery, then get a-line, CVP, PA cath

TEE in extreme cases and you’re tryna get fancy

Question 28

Goals on emergence for pts with HTN

Answer 28

Again we're avoiding SNS outflow
We want a smooth emergence!
- Opioids
- Lidocaine
- BBs, NTG
- Deep extubation (if not a difficult airway)

As we shut the gasses off, we’ll see a rebound increase in BP. Work in the stuff above as appropriate.

Question 29

How should HTN be treated post-op as long as pain is under control?

Answer 29

Labetalol 5-20mg IV Q 10min
Hydralazine 2.5-10 mg IV Q 10-20 min
NTG 0.5-10 mcg/kg/min if a-line present