HTN

Question 1

Definition of HTN

Answer 1

1. BP > 140/90 on at least two occasions
2. Reading should be measured at least 1-2 weeks apart

• Prehypertension: 120-130/80-89
• Stage 1 HTN: 140-159/90-99
• Stage 2 HN: ≥160/≥100

Question 2

Two types of HTN

Answer 2

1. Essential - Unknown etiology (idiopathic)
   
   • 95% of cases
   • Strong genetic link (maybe related to inherited biochemical abnormalities)
   • Possible Na⁺ imbalences
   • Associated with drinking, smoking, and OSA
2. Secondary - Know etiology
   
   • 5% of cases
   • Renal problems is main cause
   • Also due to endocrine, pregnancy, neurologic, drug induced, and OSA

Question 3

Treatment for essential HTN

Answer 3

1. Lifestyle Modification
   
   • Recommended for those without CV disease or end organ damage (Decrease Na intake, take in enough K and Ca exercise, lose weight, stop smokin and drinkin)
2. 2nd line treatment: Drug therapy ​​(with lifestyle mod)
   
   • Stage I: diuretic - 1st line
   • Stage II: dual therapy
   • Stage III: continue adding
   • Diabetic: ACE-I are 1st line drugs

Question 4

Treatment of Secondary HTN

Answer 4

Treat the cause

1. Often times surgical
   
   • pheochromocytoma- adrenalectomy
   • renal artery stenosis/primary aldosteronism- angioplasty (HTN d/t activation of RASS because kidneys perceive decreased blood flow
2. Drug therapy if not a candidate for surgery

Question 5

Anesthesia considerations for patients on ß-blockers. Who should they be avoided in?

Answer 5

• Patients who are on them should be take them the morning of surgery to prevent rebound SNS stimulation
• Rebound SNS stimulation is d/t upregulation of receptors
• AVOID in ß-blockers
  
  • Asthmatics
  • COPD
  • CHF
  • HB
  • Sick Sinus Syndrome

Question 6

Anesthesia considerations for patients on Methyldopa and Clonidine?

Answer 6

1. A2 agonist used to treat HTN
2. Can cause rebound HTN
3. Will DECREASE anesthetic requirements

Question 7

Anesthesia considerations for patients on Prazosin

Answer 7

1. A1 blocker
2. Compensatory vasoconstriction is blocked
   
   • there may be an exaggerated drop in BP during spinal/epidural block

Question 8

Anesthesia considerations for patients on Hydralazine

Answer 8

1. Causes potassium influx and hyperpolarization
2. May cause angina in those with ischemic heart disease (not sure the mechanism of action)

Question 9

Anesthesia considerations for patients on ACE inhibitors

Answer 9

1. They are the ‘prils
2. Associated with drop in BP and hemodynamic instability.
3. tell patients to HOLD THE MORNING OF SURGERY (24-48 hours)
4. If they take it they will have very labile blood pressures!!!

(BP regulated by three systems - GA knocks out the autonomic, ACE-I take out the RAAS and that leaves the vasopressin system left →they are very likely to be volume dependent (if they take their meds). Hypotension responsive to fluid and sympathomimethic drugs- if they are resistant ususally vasopressin or a vasopressin analough will do the trick!)

Question 10

Anesthesia considerations for patients on Angiotensin II blockers

Answer 10

1. ‘Artans
2. Drop in BP with induction

(Patients who take ARBS may be refracitve to convetional vasoconstrictors like phenylephrine and ephedrine → may need to use vasopressin or vasopressin analogue)

Question 11

Hypertensive crisis

1. What is it?
2. What can it cause
3. what is the treatment

Answer 11

Acute DBP > 130 mmHg

or

parturient with DBP> 109 mmHg

Question 12

What can a hypertensive crisis cause?

Answer 12

1. Encephalopathy
2. SAH (Subarachnoid Hemorrhage)
3. CHF
4. Renal insufficiency

Question 13

How is a hypertensive crisis treated?

Answer 13

1. Goal is to lower BP promptly, but gradually.
2. Monitor BP reduction with an a-line. and end organ profusion with a foley
   
   • Decrease MAP by 20% during first 2 hours
   • Then even more gradually reduce BP over the next 24-48 hours (160/110 - if no signs of end organ ischemia)
3. Pharmacologic interventions include
   
   • Sodium Nitroprusside (Nipride): 0.5-10.0 mcg/kg/min
     
     • Immediaate onset and short DOA
     • DRUG OF CHOICE
   • Nicardipine (dihydropiridine CCB) - says Stoelting
   • NTG: 5-200 mcg/min
   • Labetolol: 40 - 80 mg q 20 min
   • Esomolol: 50-300 mcg/kg/min

Question 14

The preoperative evaluation of a person with essential hyperteshion should elicit which things?

Answer 14

1. The adequacy of BP controll
   
   1. Is it controlled or uncontrolled?
      
      • a DBP of 110-115 should have surgery postponed
   2. What is their normal Blood Pressure
   3. What is their medication therapy?
   4. Do they have evidence of end-organ damage?
      
      • Angina, CHF, LV hypertrophy
      • Renal insufficiency
      • CVA
      • Peripehral Vascular Disease

Question 15

Anesthetic management of INDUCTION for patients with HTN

Answer 15

1. Minimize SNS stimulation on DVL and intubation (they often have exagerated HTN with this and tachycardia and HTN is a risk for ISCHEMIA)
2. What to do?
   
   1. Increasing volatile agent
   2. Give Esmolol prior to DVL: 10-20 mg
   3. additional opioids
   4. Lidocaine
      
      • IV: 1-1.5 mg/kg
      • LTA: 5cc of 2-4%
3. ​​​​ Efficient DVL: <15 seconds
4. NO KETAMINE!!!

Question 16

Management of MAINTINENCE of anesthesia for patients with HTN

Answer 16

GOAL = to adjust anesthetic depth to minimize wide shifts in hemodynamics

(It is common for patients with HTN to have wide hemodynamic shifts)

1. Chose a VA that is easily and quickly titrated
   
   • Low BG coefficient→ des (0.42) or sevo (0.69)
2. Rely on multiple agents! = better total coverage
   
   • Use a balanced technique like the pros -
3. Have phenylephrine and ephedrine readily available -
   
   • Consider neo gtt if unable to get adequate depth of anesthesia (i dont get this, but it is in the notes)

Question 17

Post-op goals for pts with HTN

Answer 17

Minimize SNS stimulation from pain and N/V

Question 18

What are the blood gas coeficients of the volitile agents?

Answer 18

Nitrous Oxide: 0.47

Desflurane: 0.42

Sevoflurane: 0.69

Isoflurane: 1.4

Enflurane: 1.8

Halothane: 2.3

Question 19

Treatment of intraoperative HYPERtension

Answer 19

1. It’s usually due to pain!! →Opioids (if d/t pain)
2. Increase volitile anesthetics →will decrease SVR
3. ß-Blockers
4. NTG and SNP (Nipride) →hang a drip for a longer case or need sustained controll

Question 20

Treatment of intraoperative HYPOtension

Answer 20

1. Reduce anesthetic depth →often caused by being too deep
2. Fluids
3. Sympathomimetics (neosinephrine and ephedrine)
4. Is their rhythm normal? →They may be in a Junctional
   
   1. Ephedrine is a good choice →will bring up HR
   2. Maintain Normocapnea→ HTN in patients with hypercarbia →increases heartrate and BP
   3. If the rhythm is not normal → AVOID high concentrations of IAs

Question 21

Bonus ****

What is premissive hypercapnea?

Answer 21

Allowing the PaCO₂ to increase up to 55mmHg spontaneously breathing patients to avoid or delay the need for endotracheal intubation

Question 22

Monitoring used for those with HTN

Answer 22

1. 5 Lead EKG
2. If the patient has ventricular dysfunction and is having extensive surgery
   
   • →then get a-line, CVP, and/or PA cath
3. may want to use a TEE in extreme cases

Question 23

Anesthesia management of emergence in a patient with HTN

Answer 23

Goal = Nice smooth controlled emergence → these patients will have exagerated responses → if they had labile pressures durring the surgery they will likely have labile pressures at emergence

1. Minimize SNS outflow! When the gasses start to come off the patient will begin to become hypertensive → be ready to treat or pre-treat as anticipated
   
   • Opioids
   • Lidocaine
   • ß-blockers (esmolol, labetolol)
   • NTG
2. Deep extubation (if not a difficult airway) →avoids the SNS stimulation of being awake with the ETT

Question 24

Treatment of potoperative HTN

Answer 24

1. If pain is adequately controlled→prompt treament is necessitated to decrease the risk of myocardial ischemia, stroke, dysrhythmias and CHF
2. Treat with:
   
   • Labetalol: 5-20 mg IV Q 10 min (ß1 and ß2)
   • Hydralazine: 2.5-10 mg IV Q 10-20 min (arterial > venous)
   • Sodium Nitroprusside: 0.5-10 mcg/kg/min if an a-line is present

Question 25

How to treat a intraop junctional rhythm

Answer 25

1. decrease anesthetic depth 2. maintain normocapnea ## Footnote (junctional rhythm in a healthy patient is directly realted to **anesthetic depth)**