Clinical Approach to Assessment of CPO
Clinical examination of the patient should identify signs and symptoms leading to an initial diagnosis of CPO. It is recommended that the initial clinical examination covers the following areas:
A: Airway
Usually intact, unless conscious level impaired by hypoxia or hypercapnoea.
In extreme cases, blood stained frothy sputum may be present.
B: Breathing
Tachypnoea is typical and the patient may be fighting for breath, using accessory muscles and adapting their posture to maximise air entry.
The bases may be dull to percussion as small pleural effusions are common particularly in acutely decompensated chronic heart failure.
O2 saturations are typically <90% on air.
Auscultation reveals bibasal inspiratory crepitations which extend higher up the chest as the condition worsens. In some cases wheeze predominates which can confuse the picture.
C: Circulation
Patients appear diaphoretic pale and their skin cold and clammy.
Monitoring stickers and line adhesive may not stick as the patient sweats profusely.
Sinus tachycardia is common but arrhythmias such as new atrial fibrillation may precipitate CPO.
The blood pressure is usually high; however, hypotension may be present and is associated with cardiogenic shock and increased mortality.
The heart sounds may be inaudible over the rales from the lungs but a gallop rhythm may be present. Murmurs, especially mitral regurgitation and aortic stenosis, should be listened for, and may reveal a precipitating cause.
Level of hydration should be assessed. Some patients may be fluid overloaded but many are euvolaemic. Assess the JVP, mucus membranes and urine output. Look for peripheral oedema and hepatomegaly suggesting right heart failure.
D: Disability
Initially, patients are alert and anxious. As their hypoxia worsens they may become agitated and with worsening respiratory failure may become hypercapnoeic causing their conscious level to fall.
E: Exposure
Afebrile with cold and clammy skin.