Pulmonary Pathophysiology I PPT Flashcards
EXAM 3
Pulmonary Hypertension (PH) Definition:
- A mean pulmonary artery pressure of at least 25 mmHg
- A pulmonary capillary occlusion pressure of 15 mmHg or less.
Pulmonary Hypertension (PH) Etiology:
- Drug effects
- Connective tissue disorders
- COPD
- Sarcoidosis
- Idiopathic/genetic factors
PAH 5 Main categories:
- Pulmonary arterial hypertension itself (PAH)
- PH due to left heart disease
- PH due to lung diseases and/or hypoxia
- Chronic thromboembolic pulmonary hypertension
- Causes with unknown mechanisms
Treatment of Cor Pulmonale:
- Diuretics to reduce cardiac workload; use cautiously to maintain adequate preload.
- Use supplemental O2 to achieve PaO2 > 60 mmHg or Saturation > 90%.
- Heart Lung Transplantation in severe cases.
Pre-operative Care for Cor Pulmonale:
- Eliminate or control pulmonary infections.
- Reverse bronchospasm.
- Improve secretion clearance.
- Expand collapsed/poorly ventilated alveoli.
- Correct hydration and electrolyte imbalances.
Intra-operative Management for Cor Pulmonale:
- Use regional anesthesia when high sensory levels aren’t needed.
Key points:
- Avoid hypotension.
- Volatile agents that decrease PVR are preferred.
- Isoflurane can lower PAP
- Avoid N2O as it increases PVR
- Intravenous agents generally have little effect on PVR.
- Ketamine should be avoided due to its potential to increase PVR.
- Crucial to avoid any manipulations that could increase PAP during anesthesia stages.
Intra-operative Principles for Cor Pulmonale:
- Maintain good oxygenation.
- Avoid acidosis.
- Avoid exogenous and endogenous vasoconstrictors.
- Avoid stimuli that increase sympathetic tone.
- Avoid hypothermia.
Pulmonary Embolism (PE) is caused by:
- A dislodged thrombus entering the pulmonary vascular bed.
- Significant thrombus obstruction leads to forward ischemia and rearward cardiac overload.
Pulmonary Embolism (PE) Etiology:
- Primarily caused by Deep Vein Thrombosis (DVT).
- Venous thrombi formation promoted by
Virchow’s triad:
- Stasis of blood flow.
- Venous injury.
- Hypercoagulable state.
Thromboembolic Risk Factors:
- Hereditary Thrombophilias
- Acquired Surgical Predisposition
- Acquired Medical predisposition
Thromboembolic Risk Factors
Hereditary Thrombophilias:
- Protein C deficiency
- Protein S deficiency
- Antithrombin II deficiency
- Factor V leiden mutation
- Prothrombin 20210 G A variation
- Hyperhomocysteinemia
- Dysfibrinogenemia
- Familial plasminogen deficiency
Thromboembolic Risk Factors
Acquired Surgical Predispositions
- Major thoracic, abdominal, or neuro procedures
- General anesthsia > 30 min
- Hip arthroplasty
- Knee arthroplasty
- Knee arthroscopy
- Hip fracture
- Major trauma
- Open prostatectomy
- Spinal cord injury
Thromboembolic Risk Factors
Acquired Medical Predispositions
- Previous venenous Thromboembolism
- Advance age > 60 yr
- Malignancy
- CHF
- CVA
- Nephrotic syndrome
- Estrogen therapy
- Pregnancy
- Postpartum period
- Obesity
- Prolonged immobilization
- Antiphospholipid antibody syndrome
- Lupus anticoagulant
- Inflammatory bowel disease
- Paroxysmal nocturnal hemoglobinuria
- Behcet syndrome
Pulmonary Embolism (PE) Pathophysiology:
- Occlusion of the pulmonary artery decreases ventilation distal to the obstruction.
- Result: Bronchoconstriction due to alveolar PCO2 (PACO2) effect on local small airways.
- Reduced airflow to the unperfused lung minimizes wasted ventilation.
Pulmonary Embolism (PE) Clinical Features:
- Clinical presentation heavily influenced by embolus size.
- Signs and symptoms of PE are varied and nonspecific, overlapping with many disorders.
Differential Dx of Acute Intraoperative PE
- Anaphylactic reaction
- Aortic dissection
- Aortic stenosis
- Brain stem stroke
- Bronchospasm
- Heart failure
- Hypertrophic cardiomyopathy
- Myocardial infarction
- Pulmonary hypertension
- Tension pneumothorax
Most common symptoms of Pulmonary Embolism:
- Unexplained dyspnea
- Chest pain (either pleuritic or atypical)
- Anxiety
- Cough
Most common signs of Pulmonary Embolism:
- Tachypnea
- Tachycardia
- Low-grade fever
- Left parasternal lift
- JVD
- Tricuspid regurgitant murmur
- Accentuated P2
- Hemoptysis
- Leg edema, erythema, tenderness
Diagnostic tests for suspected Pulmonary Embolism
- Chest CT (most accurate)
- D-dimer (rule out)
ECG signs assocaited with PE
- Tachycardia
- Negative T wave in V1-V5
- Negative T wave in II, III, aVF
- Right axis deviation > 90 degrees
- Pulmonary P wave
- R > S or Q in VR
- RV ischemia
- Complete or incomplete RBBB
Medical Management for Acute PE
- Begin UFH IV
- aPTT goal 80 sec
- Volume resucitation 500-1000 mL
- Give vasopressors and Inotropes
- Determine risk of thrombolytic therapy
- Consider IVC filter, embolectomy, sx embolectomy if therapy is too risky
- Avoid combination of Thrombolytics and IVC filter insertion
Prevention of Venous Thromboembolism by condition
Pulmonary Embolism (PE) Anesthetic Management:
- Focus on preventing further embolism and supporting respiratory and cardiovascular function.
- Aims to maintain vital organ function and minimize anesthetic-induced myocardial depression.
PE Anesthesia induction and maintenance must avoid:
- Worsening arterial hypoxemia
- Systemic hypotension
- Pulmonary hypertension
Part II
Pulmonary Embolism (PE) Anesthetic Management:
- Anesthesia should use drugs that avoid significant myocardial depression.
- AVOID Nitrous oxide potential to increase PVR
- A nNMBs drug that does not release histamine is preferred for its safer profile.
Avoid: Mivacurium & Atracurium
Initial indicators of Pulmonary Embolism (PE) During Anesthesia:
- Decrease PETCO2
- Tachycardia
Detection of Pulmonary Embolism (PE) During Anesthesia:
- Decrease PETCO2 (initial)
- Tachycardia (initial)
- Decrease SaO2
- Abnormal ABGs
- Arterial hypoxemia
- Increased PAP and CVP
- Bronchospasm can occur
- ECG may show right axis deviation
- Incomplete or complete RBBB
- Peaked T waves
What are the classic nonspecific signs of a Massive Pulmonary Embolism?
- Abrupt, unexplained hypotension
- Tachycardia
Pulmonary Embolism (PE) Anesthesia Management Intraop:
- Prevent CV complications
- Ensure airway by ETT
- Stop anesthetics agents
- Start 100% FiO2
- Support circulation IV fluids/blood
- Norepinephrine (vasopressor of choice)
- Epi, Dopamine, Dobutamine + Norepi
Part II
Pulmonary Embolism (PE) Anesthesia Management Intraop:
- Treat ventricular dysrhythmias with IV lidocaine or amiodarone.
- Optimize oxygenation with PEEP
- Consider thrombolysis or pulmonary embolectomy
- Prepare for severe hemodynamic challenges
- Continue resuscitative efforts
- In extreme cases, cardiopulmonary bypass may be required until obstruction is relieved
Cor Pulmonale Primary Tx Focus:
- Improve gas exchange
- Especially in COPD patients
Normal pulmonary circulation is:
- Passive
- Low resistance
- Highly distensible
Pulmonary Hypertension is caractherized by:
- Increase Vascular tone
- Growth and proliferation of pulmonary vascular smooth muscle
Overload of the Right Ventricle can lead to:
- Cor Pulmonale
- Inhibition of coronary perfusion
PH initial reversible vasoconstriction may progress to:
- Muscle Hypertrophy
- Irreversible degeneration
Pulmonary Hypertension clinical features:
- Dyspnea (first common)
- Excercise intolerance (first common)
- Angina
Pulmonary Hypertension Diagnosis:
- ECG changes
- CXR
- Cardiac Cath
- Open-lung biopsy
- ETCO2
ECG changes seen with PH:
- Right atrial hypertrophy
- Right ventricular hypertrophy
Chest x-ray on PH will show:
Enlarged pulmonary artery
Pulmonary Angiography is most informative in assessment of:
- PAH
- Cardiac reserve
- Pulmonary vasodilators therapy (effects)
Non-invasive evaluation for PH include:
Dopple echocardiography
Tricuspid valve regurgitation
ETCO2 is significantly reduced in patients with:
PAH
PAH Pharmacological treatment:
- Vasodilator agents(reversible vasoconstriction)
- Alpha and Beta Adrenergic (least benefit)
- Prostacyclin (Best benefit)
Medications class commonly used with PAH:
- Soluble Guanylate Cyclase
- Endothelin Receptor Antagonist
- Phosphodiasterase-5 Inhibitors
- Prostacyclins
PAH Anesthetic Management:
- Prevent increases in PAH
- Avoid major hemodynamic changes
PAH PreOp Eval includes:
- ECG
- Echocardiogram
- CXR
- ABGs
In PAH this condition should be optimize Preop:
COPD
Chronic therapy for PAH should not be ________ for fears of its hypotensive effect
Discontinue
PAH intraop hypotension treatment:
- Vasopressors
- Treat aggressively
Anesthesia techniques used with PAH:
- General (more complications)
- Regional
PAH General anesthesia induction use:
- Etomidate
- Avoid KETAMINE (increase PVR)
- Avoid Desflurane
- Avoid hypoxemia
- Avoid hypercarbia
- Avoid acidosis
- Avoid pain
- Avoid hypothermia (increases PVR)
- Use A-line monitoring
What is Cor Pulmonale?
Right heart failure 2/2 pulmonary pathology
Cor Pulmonale leading cause:
COPD
Cor Pulmonale arises from variety disorders including:
- PAH
- PAH with left heart disease
- PAH with lung disease/hypoxemia
- PAH due to chronic thrombotic /embolic disease
- Miscellaneous
COPD is associated with:
- Functional loss of pulmonary capillaries
- Subsequent arterial hypoxemia
Pulmonary vasoconstriction is the leading cause of:
Chronic Cor Pulmonale
Conditions associated with Hypoxic Pulmonary Vasoconstriction:
- COPD
- Bronchioectasis
- Chronic mountain sickness
- Cystic fibrosis
- Idiopathic alveolar hypoventilation
- Obesity-related hypoventilation syndrome
- Neuromuscular disease
- Kyphoscoliosis
- Pleuropulmonary fibrosis
- Upper airway obstruction
Conditions that produce obstruction or oblitration of the pulmonary vasculature:
- Pulmonary embolism
- Pulmonary fibrosis
- Pulmonary lymphangitic carcinomatosis
- Idiopathic PAH
- Progressive sytemic sclerosis
- Sarcoidosis
- Intravenous drug abuse
- Pulmonary vasculitis
- Pulmonary venoocclusive disease
Pulmonary hypertsion is always an underlying pathology of
Cor pulmonale
Sustain pulmonary hypertension produces:
- Hypertrophy of smooth muscle in the tunica media
- Remodeling of vascular smooth muscle
Remodeling of smooth muscle leads to:
Increase in PVR
Symptoms of Cor pulmonale:
- Retrosternal pain
- Cough and dyspnea on exertion
- Weakness
- Fatigue
- Early exhaustion
- Hemoptysis
- Occasional hoarseness (LRLN compression)
- Syncope
Physical sings of Cor Pulmonale:
- Elevation of JV pressure
- Cardiac heave or thrust along the left sternal border
- S3 gallop
- S4 sound
- Wide split S2
- Pulmonic and Tricuspid insufficiency murmur
Cor Pulmonale late signs:
- Hepatomegaly
- Ascites
- LE edema
Cor Pulmonale Diagnosis:
- Chest radiography
- Echocardiography
- MRI
Three major drug classes for PAH treatment:
- Prostanoids
- Endothelin receptor antagonist
- Phosphodiesterase inhibitors
Cor Pulmonale Preop Eval:
- Control acute or chronic pulmonary infections
- Improve clearance secretions
- Hydration
- Reversal of bronchospasm
- Correct any electrolyte imbalance
