Test 2 Flashcards
Pulmonary Embolism - PE
A collection of particulate matter that enters the venous system and lodges in the pulmonary vessels
Clinical Signs and Symptoms of a PE –
dependent upon number and size of emboli
Symptoms:
▪ impending doom – restlessness - apprehension
▪ dyspnea with …
▪ abrupt onset ▪ pleuritic chest pain ▪ tachycardia
▪ cough
▪ hemoptysis
Signs: ▪ tachypnea ▪ pleural friction rub ▪ S3 or S4 ▪ fever ▪ petechiae ▪ ↓SaO2 ▪ diaphoresis ▪ ST and T wave changes if severe
Priority Problems of a PE
▪ Hypoxemia r/t mismatch of perfusion and alveolar respiration
▪ Hypotension due to reduced forward flow of blood
▪ anxiety
▪ potential for bleeding due to anticoagulants
What is PaO2 and Fio2?
partial pressure arterial O2 (get this from your ABGs)
Fio2 = fraction of inspired o2 (A patient on room air = fio2 = .21)
Diagnosis of a PE:
▪ Abnormal ABG’s ▪ early respiratory alkalosis ▪ later respiratory acidosis see Fraction of Inspired oxygen (PaO2-FiO2) ▪ eventually metabolic acidosis
▪ Chest X-ray
Non specific x 24 hrs unless very large PE
▪CT Scan, MDCTA (very specific)
▪ TEE, Doppler ultrasound
▪Lung scan (ventilation/perfusion scan), pulm angiogram
Nursing Care for PE:
improve ventilation and perfusion, minimize risk of additional clot formation, prevent complications
▪ respiratory assessment
▪ administer O2 ▪ crackles
▪ cardiac assessment
▪ S3 S4
▪ anticoagulation medications
▪ IV heparin
▪ warfarin
▪ thrombolytic
▪ surgical management
▪ vena cava filter
Acute Respiratory Failure definition:
pulmonary system fails in one or both functions; oxygenation and CO2 elimination
Acute Resp. Failure
Ventilatory Failure
Oxygenation Failure
Combined Failure
Acute Respiratory Failure
▪ Clinically Defined
PaO2 < 60mmHg OR PaCO2 > 50mmHg
SaO2 < 90% with ABG pH < 7.30
▪ Manifestations often subtle at onset and
progress rapidly
Patient is always hypoxemic
what is V/Q?
“V” - ventilation-air that reaches the lungs
“Q” - perfusion-blood that reaches the lung
What is normal V and normal Q?
Normal V (ventilation) is 4 L of air per minute Normal Q (perfusion) is 5L of blood per minute. Normal V/Q ratio is 4/5 or 0.8.
When the V/Q is higher than 0.8, it means ventilation exceeds perfusion.
When the V/Q is < 0.8, there is a VQ mismatch caused by poor ventilation.
Ventilatory Failure:
normal perfusion & abnormal ventilation
▪ PaCO2 > 45mmHg in patients with otherwise healthy lungs
Oxygenation Failure:
normal ventilation with abnormal perfusion
What are possible causes of oxygenation failure?
Impaired diffusion at alveolar level Right to left shunt in pulmonary vessels Low O2 concentration atmospheric air Failure of Hgb to bind to Oxygen V/Q mismatch Acute Respiratory Distress Syndrome (ARDS) classic case
Combined Ventilatory & Oxygenation Failure:
Diseased bronchioles & alveoli (oxygenation failure)
-ex. Ephysema, asthma
Increased work of breathing leads to ineffective respiratory muscle function (ventilatory failure)
What are the CNS signs and symptoms of V/Q mismatch?
▪ Irritability
▪ Confusion
▪ Impending doom
▪ Somnolence
What are the respiratory signs and symptoms of V/Q mismatch?
▪ Dyspnea
▪ Increased Depth - hypoxemia
▪ Decreased Depth - hypercapnia
What are the cardiovascular signs and symptoms of V/Q mismatch?
▪ Tachycardia - early ▪ HTN - early ▪ Bradycardia - late ▪ Hypotension - late ▪ Arrhythmias
Acute Respiratory Distress Syndrome (ARDS):
syndrome of lung inflammation and injury, potentially fatal non-cardiac pulmonary edema. Often associated with acute lung injury (ALI)
Characteristics of ARDS?
▪ acute and refractory hypoxemia despite 100% FIO2 ▪ dyspnea ▪ decreased lung compliance ▪ alveolar collapse ▪ bilateral infiltrates “white out” → ▪noncardiac-associated bilateral pulmonary edema
Pathophysiology of ARDS:
activation of the systemic inflammatory response in response to direct or indirect lung injury
Phases of ARDS:
Phases: Early changes of SOB and increased HR Infiltrates, pulm. Edema Increasing hypoxemia (days 2-10) Pulmonary fibrosis
What are Direct Mechanisms of ARDS:
lead to alveolar inflammation and injury: ▪ aspiration ▪ inhalation injury ▪ contusion ▪ embolism ▪ radiation ▪ reperfusion injury ▪ oxygen toxicity
What are indirect Mechanisms of ARDS:
activation of SIR from outside the lung, tissue destructive cytokines travel to the lungs ▪ shock ▪ sepsis ▪ trauma ▪ pancreatitis ▪ drug overdose ▪ massive blood transfusion ▪ disseminated intravascular coagulopathy
Diagnosis of ARDS:
▪ Abnormal Chest X-ray
▪ Abnormal ABG’s
▪ Refractory hypoxemia
▪ despite supplemental O2
▪ Abnormal Pulmonary Function Tests
▪ ↓ compliance
▪ ↓ FRC
