Hypertension Flashcards
Hypertension is defined as a sustained SBP > ________mmHg and/or a DBP > ______ mmHg
SBP >130 mmHg
DBP > 80 mmHg
HTN effects >_______ million people in the US.
100
Nearly 1/2 adults
Hypertension percentages per demographic (African american, white, asian, hispanic):
African Americans: 40%
Whites: 30%
Asians: 29%
Hispanics: 27%
Classification of systemic blood pressure in adults:
At what SBP and DBP is BP considered elevated?
SBP: 120-129
DBP: <80
What SBP and DBP is considered stage1 hypertension?
SBP: 130-139
DBP: 80-89
What SBP and DBP is considered stage 2 hypertension?
SBP: ≥ 140
DBP: ≥ 90
What issues can be caused from chronic hypertension?
- Ischemic heart disease
- Stroke
- Renal failure
- Retinopathy
- PVD
- Increased mortality
What is a common risk factor for perioperative morbidity and mortality?
Hypertension
What disease processes are included in chronic hypertension?
- Isolated systolic hypertension
- Isolated diastolic hypertension
- Combined systolic and diastolic HTN
Isolated systolic HTN:
SBP: >130
DBP: <80
Isolated diastolic HTN:
SBP: <130
DBP: >80
Combined systolic and diastolic HTN:
SBP: >130
DBP: >80
_________ pulse pressure is a risk factor for CV morbidity as it correlates with vascular remodeling and stiffness
Widened
HTN can result from increased _________ and __________ _________ (or both)
Cardiac output
Vascular resistance
What are contributing factors for primary hypertension?
- SNS hyperactivity
- Dysregulation of RAAS
- Endogenous vasodiulator deficiency
Treatment for hypertensive emergencies:
What are common causes of secondary hypertension in adults?
- Hyperaldosteronism
- Thyroid dysfunction
- OSA
- Cushings
- Pheochromocytoma
Kids with HTN have secondary HTN due to _________ disease or coarctation of the aorta
renal
List of drugs that increase BP:
Psych meds and MAOIs
How is pulmonary HTN defined?
Mean PA pressure (mPAP) >20 mmHg
What are common causes of secondary HTN for kids up to age 12?
- Renal parenchymal disease
- Coarctation of aorta
What are common causes of secondary HTN for adolescents? (Not common)
- Coarctation of aorta
Symptoms of pulmonary HTN:
Accentuated S2 and S4 “gallop” heart sounds, LE swelling
Pulmonary HTN is divided into 3 hemodynamic profiles based on what two things?
PA wedge pressure (PAWP) and pulmonary vascular resistance (PVR)
What are common causes of secondary HTN for young adults?
uncommon for young adults
- Thyroid dysfunction
- Fibromuscular dysplasia
- Renal parenchymal disease
What are the 3 classifications of pulmonary HTN?
- isolated precapillary PH
- isolated postcapillary PH
- combined pre and postcapillary PH
What are common causes of secondary HTN for middle age adults?
- Hyperaldosteronism
- Thyroid dysfunction
- Obstructive sleep apnea
- Cushing syndrome
- Pheochromocytoma
What are common causes of secondary HTN for older adults?
- Atherosclerotic renal artery stenosis
- Renal failure
- Hypothyroidism
Where is the primary issue in precapillary pulm HTN?
In the pulmonary arterial circulation
Chronic HTN leads to remodeling of:
- Small and large arteries
- Endothelial dysfunction
Potentially irreversible end-organ damage
Signs of precapillary pulm HTN:
PVR ≥3.0 wood units w/ normal LAP or PAWP (<15 mmHg)
What disease process does disseminated vasculopathy play a major role in?
- Ischemic heart disease
- LVH
- CHF
- CVA
- PAD
- Aortic aneurysm
- Nephropathy
Vasculopathy can be detected early on __________ by measuring common carotid intimal-to-medial thickness and _________ pulse wave velocity
- Ultrasound
- Arterial
Where is the primary issue in postcapillary pulm HTN?
Increased pulmonary venous pressure d/t elevated LAP - usually c/b left heart disease
What diagnostics can be used to track the progression of LVH?
- EKG
- Echocardiogram
Signs of postcapillary pulm HTN:
Elevated PAWP (>15 mmHg), normal PVR
What imaging is used to track microvascular changes with cerebrovascular damage?
MRI
Where is the primary issue with combined pre- and postcapillary pulm HTN:
Chronic pulmonary venous HTN with secondary pulmonary arterial vasoconstriction and remodeling
Examples of End Organ damage from HTN:
What is the typical therapeutic goal for HTN treatment?
<130/<80
____ million people in US have untreated HTN
28
What is the criteria for resistant HTN?
BP above goal despite 3 or more antiHTN meds at max dose
(Tx often includes CCB, ACE-i or ARB, Diuretic)
How do you categorize combined pre and postcapillary pulm HTN?
- Characterized by a PVR >3.0 WU and PAWP >15 mmHg
- Can be subcategorized as fixed or vasoreactive d/o the response to vasodilators, diuretics, or mechanical assistance
What is high-flow pulmonary HTN?
Occur without an elevation in PAWP or PVR and results from increased pulmonary blood flow caused by systemic-to-pulmonary shunt or high cardiac output states
What is controlled resistant HTN?
Controlled BP requiring 4 or more meds
Hemodynamic definitions of pulmonary HTN (graph)
What is refractory HTN?
Uncontrolled BP on 5 or more drugs
0.5% of patients
What is often the cause of pseudo-resistant HTN (appears resistant to drugs)?
BP inaccuracies or medication noncompliance
How do you diagnose pulmonary artery hypertension?
Right heart catheterization is required for a dx, classification and treatment plan
What are some lifestyle modifications to manage HTN?
- Weight loss
- Decrease alcohol
- Exercise
- Smoking cessation
What 4 things can increase mPAP?
- elevated resistance to blood flow within the arterial circulation
- increased pulmonary venous pressure from left heart disease
- chronically increased pulmonary blood flow
- a combination of these processes
Why is weight loss important in preventing HTN?
Continuous relationship between increased BMI and HTN
Which nonpharmacological intervention is effective in BP reduction and synergistic enhancement of drug efficacy?
Weight loss
How to calculate PVR:
PVR = (mPAP - PAWP)/COP
Pulmonary HTN can occur due to abnormalities in ____ or ____ components of pulmonary circulation, something including contributions from both
arterial or venous
How much does BP decrease with each Kg of weight loss?
1mmHg ↓ per 1kg of weight loss
What would a TTE show in someone with pulmonary artery HTN?
RA and RV enlargement and elevated tricuspid-regurgitation velocity
How does excess alcohol intake impact antihypertensive drugs?
Associated with resistance to antihypertensive drugs
Dietary _____ and _______ intake are inversely related to HTN and cerebralvascular disease
- Potassium
- Calcium
What dietary restriction can help with small/consistent BP decreases?
Salt restriction
What are the 8 ACC/AHA guidelines for BP management?
1) Out of office BP recommended for titration of BP meds
2) Treat pts with ischemic heart, cerebrovascular disease, CKD, or atherosclerotic cardiovascular disease with meds when SBP >130
3) Little data supports nonpharmacological treatment for pts without CV or cerebrovascular disease is SBP >130 or DBP> 80
4) Same HTN goals for pts with DM and CKD as general HTN population
5) ACE-Is, ARBS, CCBS, Thiazides effective in nonblack HTN pts
6) Initial therapy in black adult HTN pts w/o heart failure or CKD with CCB or thiazide diuretics
7) ACEi/ARB in pts with CKD and HTN
8) Nonpharmacologic interventions important for comprehensive BP management
What is used as a screening tool for PH?
Echo is commonly used to estimate pulmonary arterial systolic pressure (PASP)
What BP med would you use if a hypertensive African American pt with out heart failure or CKD?
CCB or Thiazide diuretic
What measurement on echo is specific for PH but can’t provide an accurate mPAP for definitive PH diagnosis?
PASP >41 mmHg
Which med would you subscribe to a patient with hypertension and CKD?
ACE-inhibitor or ARB
Which patients are beta blockers used to treat HTN?
Pts with CAD or tachydysrhythmia
Can be used for multidrug treatment in resistant HTN
Measurements in MILD PH:
mPAP = 20-30 mmHg
How many drug classes are approved for HTN?
15
Measurements in MODERATE PH:
mPAP = 31-40 mmHg
Treatment of secondary HTN is often interventional; What interventions are included?
- Surgical correction of renal artery stenosis
- Adrenal adenoma
- Pheochromocytoma
Measurements for SEVERE PH:
mPAP >40 mmHg
Normally, pulmonary circulation can accommodate a ____ increase in COP without a marked change in ____
fourfold; mPAP
What percent of PAH cases are genetic?
What mutation causes it?
3% - mutations in bone morphogenetic protein receptor type 2 (BMPR2)
How is BP controlled if renal artery repair is not possible?
ACE-inhibitors with or without diuretics
Other than genetic, what are the remaining cases of PAH?
“Associated PAH” - attributed to disease processes, drugs or toxins
What meds are NOT indicated in bilateral renal artery stenosis?
ACE-inhibitors, ARBs, and Direct Renin Inhibitors→ can accelerate renal failure
PAH was historically a disease of young women with a median survival rate of what?
3 years
(demographic shift now shows older patients and more men being diagnosed)
What is common drug to treat primary hyperaldosteronism?
Aldosterone antagonist → Spironolactone
How many PAH patients have long term improvements with CCB?
1:8
Despite improvements in therapy for PAH, what is the one year mortality rate?
~15%
Preop BP assessment is often complicated by ________
Anxiety
What leads to pathologic distortion of the pulmonary arteries?
Sustained vasoconstriction and remodeling
T/F: Multiple elevated BP readings over time can be used to diagnose HTN
True
How is HTN from pheochromocytoma managed?
Combo of pharmacologic and surgical approach
What are the 3 main classes of vasodilator drugs for PAH?
- Prostanoids
- Endothelin receptor antagonists
- Drugs than enhance nitric oxide/guanylate cyclase pathways
*combination therapy is often required for adequate tx of PAH
MOA of prostanoids:
- mimic the effect of prostacyclin to produce vasodilation while inhibiting platelet aggregation
- they also have anti-inflammatory effects and may reduce proliferation of vascular smooth muscle cells
Should surgery be delayed if the pt has elevated BP?
No necessarily→ do not need to delay in asymptomatic pts without risk factors
What should you do if you take a BP in preop and its elevated?
Check BP on contralateral arm
What are the prostanoid meds?
- Epoprostenol (IV)
- iloprost (inhaled)
- treprostinil (SQ, IV, INH, PO)
- beraprost (PO)
When should surgery be delayed d/t HTN?
- Pt experiencing extreme HTN (>180/>110)
- End organ injury that could be reversed with BP control
Which prostanoid is the only one proven to reduce mortality?
Epoprostenol
What symptoms may indicated secondary HTN?
- Flushing, sweating, palpitations→ pheochromocytoma
- Renal bruit→ renal artery stenosis
- Hypokalemia→ hypoaldosteronism
What causes vascular endothelial dysfunction associated with PAH?
Imbalance between vasodilating (nitric oxide) and vasoconstricting (endothelin) substances
T/F: Continue all BP meds when surgery is indicated
False: Continue BP meds except ARBs and ACE-is
How do endothelin receptor antagonists help PAH?
Improve hemodynamics and exercise capacity
How does nitric oxide/guanylate cyclase help with PAH?
NO produces pulmonary vasodilation by stimulating guanylate cyclase and cGMP. in smooth muscle cells.
- the effect is transient because nitric oxide is quickly bound by hgb and degraded by PDE type 5
What could happen is beta blocjers or clonidine are stopped before a procedure?
Rebound HTN
What could happen if CCBs are stopped prior to surgery?
Increased perioperative CV events
Even though we dont delay surgery for HTN, these patients have increased risk of:
- Blood loss
- MI and CVA
What are hypertensive pts prone to intraop?
Hemodynamic volatility (physiologic and BP meds on board)
What are the two types of Nitric oxide therapy?
- continuous inhaled nitric oxide is used in perioperative and critical care settings
- chronic therapy has been directed toward PD-5 inhibitors to prolong the half-life of nitric oxide
Patient with organ damage from chronic HTN are less resilient to period of hypotension and have increased risk of:
- Acute kidney disease
- Myocardial injury
With PAH, considerations should be given to procedures with potential for what??
- venous embolism
- elevations in venous and/or airway pressure
- hypoxic pulmonary vasoconstriction
- reduction in pulmonary vascular volume
- systemic inflammation
- emergency procedures
How do induction drugs impact BP?
Hypotension
Nonspecific symptoms of PAH:
- fatigue
- dyspnea
- cough
How does direct laryngoscopy and intubation impact BP?
Hypertension and tachycardia
Severe symptoms of PAH:
Angina and syncope, which can occur with exercise if coronary blood flow doesn’t meet the demands of a hypertrophied RV
What monitors are necessary for induction in patients with hypertension?
- Pre-induction A-line
- Multimodal induction (Esmolol)
Poorly controlled HTN is often accompanied by ____________
Hypovolemia (esp if patient is on diuretics)
What might help prevent hypotension and improve hemodynamic stability during induction in pts with HTN?
Modest volume loading→ may be bad idea in pts with LVH and diastolic dysfunction
What might a patient with PAH exhibit on assessment?
- Parasternal lift
- Accentuated S2, S3 or S4 gallop
- JVD
- peripheral edema
- hepatomegaly
- ascites
When using vasoactive drugs what things should be considered?
- Pts age
- Functional reserve
- Meds
- Planned surgery
Although rare, compression of a dilated PA can cause what?
RLN damage and hoarseness
What are the categories of hypertensive crisis?
- Urgent
- Emergent
History of PH should prompt further evaluation of what?
Functional status, cardiac performance, and pulmonary function tests
What are potential causes of perioperative emergencies?
- CNS Injury
- Kidney injury
- CV injury
When with pregnancy induced HTN (PIH) may have end organ dysfunction with DBP >______
100
manifests as encephalopathy
What are the current treatment guidelines for peripartum HTN intervention?
SBP >160/ DBP>110
What helps monitor BP to slowly titrate down high BP and avoid overshooting?
A-line
What is the 1st line drug for peripartum HTN?
Labetalol
What is the gold standard for rapid arterial dilation?
Sodium nitroprusside (fast onset and titratability)
What is a 3rd generation dihydropyridine CCB with an ultrashort duration of action (1 min half life) and selective arteriolar vasodilating properties?
Clevidipine (not widely used because expensive)
For patients with moderate/severe PH, what is recommended prior to moderate-high risk surgery?
Right heart cath
Why is a left heart cath indicated in patients with left heart disease?
Inaccurate LVEDP may lead to misclassification of PH and inappropriate treatment
During a right heart cath, what is performed to determine responsiveness to vasodilator therapy?
Vasoreactivity testing with inhaled nitric oxide
What percent of PAH patients are non-responsive to inhaled nitric oxide?
85-90%
- those that are responsive also responded to CCBs and may benefit from other targeted therapy
What is a second generation dihydropyridine CCB that has a longer half life (30 min)?
Nicardipine (less titratable than clevidipine)
What is the main primary intraoperative goal for patients with PAH?
Maintaining optimal “mechanical coupling” between the right ventricle and pulmonary circulation to promote adequate left-sided filling and systemic perfusion
What other perioperative interventions need to be considered for patients with PAH?
Anything that may affect RV preload, inotropy, afterload, and O2 supply/demand
What perioperative complexities can increase risk of complications in PAH patients?
- transient HoTN
- mechanical ventilation
- modest hypercarbia
- small bubbles in IV
- T-burg position
- pneumoperitoneum
- single-lung ventilation
What is a hallmark of PAH?
Increased RV afterload
What does increased RV afterload lead to?
RV dilation, increased wall stress, RV hypertrophy
The interaction between the RV and pulmonary circulation is ____ and ____, involving the compliance and ____ of large and small vessels
Pulsatile and dynamic; “stiffness”
What affects RV pulsatile load?
Surgical stimulation
What vent settings can affect RV afterload?
PEEP, hypoventilation, hypercarbia, acidosis, atelectasis
In contrast to the LV, the thinner-walled RV is subject to greater ____ for the same degree of ____; leading to what?
wall tension for the same degree of EDV;
leading to increased RV O2 demand
Under normal circumstances, the RV intramyocardial pressure is lower than what?
Aortic root pressure
- RV coronary perfusion occurs throughout the cardiac cycle
In PAH, elevated RV pressure leads to what?
Increased coronary flow during diastole - this makes the RV more vulnerable to systemic HoTN, worsening the O2 supply/demand mismatch and potentially causing myocardial ischemia
What is the lethal combination that can lead to RV ischemia?
RV dilation, insufficient LV filling, reduced stroke volume and systemic hypotension
Orthopedic procedural considerations for patients with PH:
Increased perioperative morbidity and mortality with undergoing hip and knee replacement
What is important to consider with laprascopic procedures in PH patients?
Pneumoperitoneum impacts biventricular load and pump function
*the combination of pneumoperitoneum, head down position, and increased AW pressure increases RV pressures and afterload
What 3 features of lung collapse are particularly relevant?
- Some centers transiently pressurize the chest to induce atelectasis
- There is potential for systemic hypoxia
- HPV will further increase RV afterload
What medications are recommended during single lung ventilation?
Inhaled pulmonary vasodilators
