CPAP in patients with acute cardiogenic pulmonary oedema

One can think of acute cardiac failure in terms of forward failure (the inability to drive the circulation) or backward failure (the congestion caused by an inefficient pump). Backward failure causes pulmonary oedema and is often associated with a normal or high blood pressure. Treatment aims toward off-loading the heart. Medical therapy does this by sitting the patient up which reduces venous return, and giving frusemide, diamorphine and nitrates for their vasodilator properties. When medical...

Noninvasive CPAP

Non-invasive CPAP was first introduced in the 1980s as a therapy for obstructive sleep apnoea OS A . This is when a tight-fitting face or nasal mask delivers a single pressure throughout the patient's respiratory cycle. It is therefore not ventilation. In OSA, CPAP prevents pharyngeal collapse. CPAP can also be delivered through an endotracheal tube or tracheostomy tube in spontaneously breathing patients and is usually used this way during weaning. The application of a continuous pressure...

Interpreting an arterial blood gas report

Arterial blood gas analysis can be performed quickly and gives useful information about A oxygenation , B ventilation and C perfusion - which is why it is one of the first tests with bedside glucose measurement performed in critical illness. However, many clinicians fail to carry out a full analysis and benefit from information that could influence therapy. The box below describes the 6 steps in arterial blood gas analysis 2. What is the primary acid-base abnormality An abnormal pH always...

Low flow devices nasal cannulae simple face masks and reservoir bag masks

Nasal cannulae are commonly used because they are convenient and comfortable. They deliver 2-4 litres per minute of 100 oxygen in addition to the air a person is breathing. If a person is breathing slowly with 10 breaths per minute and 500 ml tidal volumes, the minute volume or inspiratory flow rate will be only 5 litres per minute. So the patient receives 2 litres per minute of 100 oxygen plus 3 litres per minute of air. Two-fifths of what the patient is breathing is 100 oxygen. However, a...