Acute LVF and Pulmonary Oedema Flashcards
What is acute left ventricular failure?
left ventricle not able to adequately move blood which causes a backlog
How can acute LVF lead to pulmonary oedema?
- Backlog of blood into left atrium, pulmonary vein and lungs
- vessels begin to leak fluid due to increased volume and pressure
- lung tissue and alveoli become full of interstitial fluid (pulmonary oedema)
What does pulmonary oedema cause?
- interferes with gas exchange
- causing shortness of breath and oxygen desaturation
What can trigger acute LVF?
- Iatrogenic (IV fluids in elderly patients with impaired LV function)
- Sepsis
- MI
- Arrhythmias
How would acute LVF present?
- Rapid onset breathlessness
- exacerbated by lying flat
- low oxygen without increase in CO2 in blood (type 1 respiratory failure)
- cough (frothy white/pink sputum)
- Look + feel unwell
What could be seen on examination of acute LVF patient?
- inc respiratory rate
- reduced O2 sat
- Tachycardia
- 3rd heart sound
- bilateral basal crackles on auscultation
- hypotension (can cause cariogenic shock)
What signs and symptoms can be sign in patients with acute LVF due to underlying causes?
- Chest pain in acute coronary syndrome
- fever in sepsis
- palpitations in arrhythmias
What would you find on examination of a patient who also had right sided HF?
- raised JVP
- peripheral oedema
What medication can be given to clear fluids?
Furosemide
What will the work up of patient with acute LVF include?
- History
- CV examination
- ECG (check for arrhythmias and ischaemia)
- Arterial blood gas
- Chest Xray
- Bloods
What can blood tests tell you about a patient with acute LVF?
Cause of LVF i.e.
- infection
- BNP and troponin if MI
- kidney function
What is BNP and when is it released?
- B-type Natriuretic peptide
- Released by heart ventricles when myocardium stretched beyond normal
- so high BNP = heart overload with blood
What are the causes of raised BNP?
- Tachycardia
- Sepsis
- Pulmonary embolism
- renal impairment
- COPD
Are BNP levels to check for acute LVF sensitive or specific?
sensitive but not specific i.e. can rule out HF but can’t confirm
What does release of BNP accomplish?
- relaxes smooth muscles in blood vessels
- reduces systemic vascular resistance
- acts as diuretic on kidneys to reduce blood volume
- easier for heart to pump
What can an ECG tell you in patients with acute LVF?
- Assess left ventricular function
- ejection fraction main measure of LV function
- below 50% = abnormal
What can be seen in CXR patient with acute LVF?
- Cardiomegaly
- upper lobe diversion
- Bilateral pleural effusion
- fluid in interlobar fissures
- fluid in the septal lines
What is the definition of cardiomegaly?
- cardiothoracic ratio of more than 0.5
- diameter of heart more than 50% of thoracic cavity
What is venous diversion?
- Usually when standing lower lobe veins in lungs contain more blood and upper veins remain small
- In LVF upper lobe veins also full and become engorged
- visible as increased prominence and diameter
What CXR findings are caused by oedematous lung tissues?
- Bilateral pleural effusions
- Fluid in interlobar fissures
- Fluid in the septal lines (Kerley lines)
How are acute LVFs managed (Pour SOD)?
- Pour away IV fluids
- Sit up (fluid fall to bottom of lungs leaving upper lobes able to gas exchange)
- Oxygen
- Diuretics
- monitor fluid balance (measure intake, urine and U&Es)
What other management strategies can be used in patients with sever pulmonary oedema and cariogenic shock?
- Intravenous opiates (vasodilators)
- Non-invasive ventilation and continuous positive airway pressure (air forcefully blown into lungs using tight fitted mask, helps open airways)
- Inotropes e.g. noradrenaline (strengthen force of heart contraction)
