Causes of wheezing in the ICU

1. • Pre-existing asthma/COPD

2. • Anaphylactic reaction

3. • Aspiration pneumonia

4. • Kinked tracheal tube

5. • Tracheal tube too far – carinal/bronchial stimulation

6. • Bronchial secretions

7. • Pulmonary oedema

8. • Pneumothorax

Signs of severe asthma needing intensive care

1. • Tachycardia (HR > 130/min)

2. • Pulsus paradox > 20 mmHg

3. • Tachypnoea (RR > 30/min)

4. • Absent wheezing

5. • Exhaustion

6. • Inability to complete a sentence

7. • PaCO2 normal or increased

8. • Hypoxia

The selective β2-agonists such as salbutamol and terbutaline are the treatment of choice for episodes of reversible bronchospasm. Patients with chronic bronchitis and emphysema are often described as having irreversible airways obstruction, but they usually respond partially to the β2-agonists or to the antimuscarinic drugs ipratropium or oxitropium. There is some evidence that patients who use β2-agonists on a ‘PRN’ basis show greater improvement in their asthma than those using them on a regular basis. In the critically ill these drugs will have to be given either nebulised or intravenously. The tracheobronchial route is preferable because the drug is delivered directly to the bronchioles; smaller doses are then required, which cause fewer side-effects. If the bronchospasm is so severe that very little drug gets to the site of action via the tracheobronchial route, then the drug will have to be given IV.