Todd Hicks, DNP, CRNA

• Pt presents for a C-section

• 34 YO, 34 week pregnant patient

with recently diagnosed

Eisenmenger’s syndrome

• Atrial septal defect

• Pulmonary hypertension (PHTN)

• Symptoms worsened during

pregnancy

• Dyspnea at rest

• Orthopnea requiring 2 pillows

while sleeping

• Associated with 50-65% mortality

rate

Consider this patient and potential management of this emergency surgery

throughout the presentation. How would you care for this patient ?

• Pulmonary hypertension (PHTN) - “A mean pulmonary artery

pressure of at least 25mmHg with pulmonary capillary

occlusive pressure of no more than 15mmHg” (Nagelhout)

• Pulmonary arterial hypertension (PAH) – subgroup of PHTN

• Characterized by vascular cell proliferation and cellular changes in

pulmonary arteries that causes increases in pulmonary vascular

resistance (PVR)

Arterial HTN• Primary:

Sporadic or

Familial

• Related to:

• Collagen

vascular dx

• Congenital

systemic or

pulmonary

shunts

• Portal HTN

• HIV

• Drugs/toxins

• Persistent PHTN

of the newborn

Venous HTN• Left ASD

• Left vent

dysfunction

• Compression of

central

pulmonary veins

• Mediastinitis

• Adenopathy or

tumors

• Pulmonary veno-

occlusive

disease

Respiratory

Disorders• COPD

• Interstitial lung

disease

• Sleep

disordered

breathing

• Alveolar

hypoventilation

disorders

• High altitude

exposure

• Neonatal lung

dx

Coagulation

Disorders• Thromboembolic

obstruction of

prox pulmonary

arteries

• Obstruction of

distal pulmonary

arteries

• Pulmonary

embolism

• Thrombus

• Tumor

• Ova

• Parasites

• Foreign

material

• In situ

thrombosis

• Sickle cell dx

Pulmonary

Vascular

Disorders• Inflammatory

• Schistosomiasis

• Sarcoidosis

• Pulmonary

capillary

hemagiomatosis

Classification of PHTN

Mild Moderate Severe

PAM > 20mmHg PAM > 35mmHg PAM > 50mmHg

There is a 1mmHg

increase in PAM per

year beyond age 50.

• Vasoconstriction

• Altered function of pulmonary vascular endothelium

• Impaired synthesis of endothelial nitric oxide

• Imbalance of prostacylins to thromboxanes

• Enhanced activity of thromboxanes

• Enhanced production endothelin

• Vascular wall remodeling

• Proliferation and thickening of vascular smooth muscle

• Thrombosis in situ

• If pulmonary vasoconstriction is sustained, hypertrophy of the

pulmonary vascular smooth muscle occurs

• Generally results in permanent increases in pulmonary

resistance

Effective therapy• Endothelin receptor agonist

therapy

• Bosentan (TRACLEER)

• 1997 first approved

• Significantly decreases

PVR in patients with PHTN

• Early diagnosis sometimes difficult, because early signs

and symptoms are often attributed to other diseases

• Dyspnea is initial symptom in 60% of patients

• However, it is present in 98% by the time of diagnosis

• Mean length of time from onset of symptoms to diagnosis is 2yrs

• Signs and symptoms indicating increased severity include:

• Dyspnea at rest

• Metabolic acidosis

• Hypoxemia

• Right heart failure

• History of syncope

Abnormalities in lung function usually mild

Arterial hypoxemia often present

Cardiac catheterization with pulmonary

arteriogram is most informative, and

assesses:

PAH

Cardiac reserve

Effects of pulmonary vasodilator therapy

Can use NTG, SNP, PGE, PGE2, prostacyclin,

isoproterenol, nifedipine, hydralazine, or

adenosine to measure reversibility of PAH

Cardiopulmonary exercise tests show:

High minute ventilation

Increased a-A O2 gradient

There is a correlation between distance

walked in 6 minutes with severity of pulmonary

HTN

• Sildenafil or monoxidil are commonly used in my home region

• cGMP–specific phosphodiesterase inhibitor

• Found selectively in arterial wall smooth muscle of lung vessels

Drug/Class Rationale Type of PAH Limitations

Prostacyclin

• Epoprostenol

• This is most

effective

• Replace endogenous

prostacyclin

• Inhibits SM prolif

• Primary

• Persistent PAH of neonate

• PAH of ARDS

• Connective tissue disease of adult

• Post-cardiac sx in peds

• Adverse effects from peripheral

infusion

• Tachyphylaxis

Nitric Oxide • Interferes with endogenous

vasoconstrictor

• Primary

• Persistent PAH of neonate

• COPD

• Bleeding risk

• Negative inotrope

• Formation of methemoglobin

CCBs • Inhibit Ca influx

• Pref act on pulm vasc

• Primary

• COPD

• High risk for negative inotropic

state

Prostaglandin E1 • Interferes with endogenous

vasoconstrictor

• PAH of ARDS • Impaired pulm metabolism can

lead to systemic hypotension

Bosentan • Endothelin receptor

antagonist

• Severe PAH • Hepatotoxicity

Alpha antagonists • Direct vasodilator

• Inhibit ADH release

• Persistent PAH of neonate

• COPD related PAH

• Systemic adverse effects

ACE Inhibitors • Inhibited formation of ATII • CT disease

• CHF

• High altitude

• No adverse effects unless

following prolonged use

Anticoagulants • Reduce risk of embolus • Primary

• Thromboembolism (acute/chronic)

• No dilatory effects

• Bleeding risk

• Anticoagulants

• Supplemental O2

• Diuretics if right heart failure

• Right heart failure secondary to pulmonary

pathology

• Pulmonary arterial hypertension results in

• Right ventricular enlargement

• Concentric hypertrophy

• Eccentric hypertrophy

• Pump failure

• COPD is the most common cause over 50% of

patients with advanced COPD have PHTN

• 3rd most common cardiac disorder over age 50

• Cor pulmonale generally refers to heart

failure resulting from the pulmonary HTN

associated with respiratory disorders

• Persistent HTN is related to persistent

pulmonary arterial vasoconstriction

associated with chronic hypoxemia or

destruction of pulmonary vessels by disease

Respiratory

Disorders• COPD

• Interstitial lung

disease

• Sleep

disordered

breathing

• Alveolar

hypoventilation

disorders

• High altitude

exposure

• Neonatal lung

dx

• Longevity is determined by underlying disease process

• In patients with COPD prognosis is good if arterial

oxygenation can be maintained at near-normal levels with

supplemental oxygen

• Long term oxygen therapy has significantly improved survival

• With hypoxic lung disease, there is a 70% mortality rate within 5yrs

following onset of symptoms of RHF

• If cor pulmonale is the result of gradual destruction

pulmonary vessels or pulmonary fibrosis, prognosis is much

poorer these are irreversible structural changes

• Retrosternal pain

• Cough

• Dyspnea on exertion

• Fatigue, weakness, early exhaustion

• Hemoptysis

• Hoarseness WHY?

• Syncope with exertion

• Increased jugular vein pressure

• Late signs:

• Hepatomegaly

• Ascites

• Lower extremity edema

Heart Sounds• S3

• S4 with significant RVH

• Accentuation of the second

heart sound & diastolic murmur

due to incompetent pulmonary

valve

• Presence of these 2

sounds denotes severe

pulmonary hypertension

Ultrasonography may

reveal tricuspid

regurgitation even in

absence of murmur

• Right heart catheterization:

• Increased mean pulmonary artery

pressures

• Often greater than 20mmHg

• Moderate pulmonary hypertension =

mean PAP > 35mmHg

• Signs of CHF often not noted until mean

PAP > 50mmHg

• Due to gradual nature of disease

• Left heart catheterization:

• Pressures are often normal

• Severe right ventricular dilation and

hypertrophy can lead to compression of

the left ventricular and impede filling

• What type of dysfunction does this

present as?

• Prominent a wave

• Reflecting enhanced right

atrial pressure in response

to decreased right

ventricular compliance

a

Normal Chest Radiograph

Normal chest film

Radiograph in Cor Pulmonale

• Right ventricular hypertrophy

• Can see left ventricular hypertrophy

• Peaked P waves in leads II, III and aVF

• Right axis deviation

• Partial or complete right BBB

Goal is to decrease workload of the right ventricle

Supplemental oxygen

Maintaining PaO2 >60mmHg and SaO2 > 90 significantly decreases mortality

Caution if hypoxic drive is necessary to maintain ventilation

Diuretics

Can increase blood viscosity

Digitalis

Vasodilators – SEE PHTN

Calcium channel blockers are used in about 1/3 of patients

Anticoagulants – SEE PHTN

Low CO and sedentary lifestyle increase risk of thromboemboli

• Bronchodilators

• Often to treat underlying COPD

• Antibiotics

• Increased risk for opportunistic pneumonias

• Septotomy – results in right to left shunt, reducing right

ventricular volume

• Heart/lung transplant

• Same principles for both

PHTN and Cor Pulmonale

• Elective surgery postponed

until reversible components

are under control

• Treat pulmonary infection

• Reverse bronchospasm

• Improve secretion clearance

• Expand poorly ventilated

alveoli

• Maintain appropriate hydration

• Correct electrolyte imbalance

• K+ - especially if patient is on

digitalis

5 KEY

PRINCIPLES1. Maintain good

oxygenation

2. Avoid acidosis

3. Avoid exogenous and

endogenous

vasoconstrictors

4. Avoid stimuli that

increase SNS

tone/outflow

5. Avoid hypothermia

• Avoid acute decreases in systemic vascular resistance in

the presence of a fixed pulmonary vascular resistance

• Etomidate commonly used IMPLICATIONS?

• What drugs can increase PVR?

• Ensure adequate depth of anesthesia before intubation in

order to avoid

• Bronchospasm WHY IS THIS BAD?

• Further increases systemic and pulmonary resistance

• Can cause acute decrease in forward flow can decompensate

• Avoid large doses of opioids as they could contribute to post

operative respiration depression

• Volatile agents provide effective bronchodilation

• Studies show that PA mean pressure is decreased by isoflurane

• Use of nitrous oxide controversial (NOT REALLY)

• May cause pulmonary artery vasoconstriction and further increase

pulmonary vascular resistance

• Other studies reveal no exacerbation of pulmonary vasoconstriction

• If used, may warrant monitoring right heart pressures in order to detect

increases

• Choice of NDMR not critical, although prudent to avoid those

that release histamine no Atracurium or mivacurium

• Type of monitoring depends on degree of severity and

invasiveness of procedure

• Direct arterial monitoring allows for frequent blood sampling for

arterial blood gases

• Right atrial pressure monitoring helps guide fluid replacement

• A sudden increase in right atrial pressures often indicates acute right

heart failure

• Questionable usefulness of PA catheter and monitoring of left

sided filling pressures

• Appropriate for extremity surgery

• If high level required, any decrease in SVR with a fixed

increase in pulmonary vascular resistance could result in

unpredictable systemic hypotension

• Caution use of central neuraxial block if level higher than T10 is

needed

• Aline

• Swan Ganz• PAP 65-70mmHg

• Pulse ox: 87-95% on facemask

• Combined Spinal/epidural was used

• Phenylephrine was used to help maintain SVR

• Able to lay at a 45 degree angle and C-section performed in this position

• Immediately after delivery, the patient received nebulized prostacyclin (PGE1)• Sats increased to 99%

• PAP decreased to 30-40mmHg

• D/C Day 7