Critically ill patient with respiratory disease
- DOI:
- 10.1093/med/9780198703860.003.0004
Patients often present critically ill to the emergency or the acute medical department with respiratory disease. This may be due to a deterioration or exacerbation of an existing condition, a first presentation of a previously undiagnosed disease, or respiratory involvement of an acute systemic disease. As with any critically ill patient, standard management is required initially to stabilize, with the focus moving to diagnosis and treatment. Often these need to take place in parallel. Depending on the presence of any pre-existing respiratory disease and the nature and severity of this, it may be important to determine disease-specific treatment and/or treatment limitations, and senior physician input should be sought for this.
Airway—
is the patient maintaining their airway? Is there snoring or gurgling? Tilt head; lift chin; use suction if good views. Is an airway adjunct necessary? Consider inserting Guedel airway or nasopharyngeal airway if GCS reduced <8 (see p. [link]). Consider calling ITU if intubation and ITU care likely to be necessary, or if the patient is rapidly deteriorating/peri-arrest and full assessment has not yet been possible (see
p. [link]).
Breathing—
cyanosis? What is the SaO2 and associated FiO2?
• Exclude tension pneumothorax clinically (see
p. [link])
• What is the respiratory rate (RR)?
• Has a blood gas been taken, and what does it show? (see
p. [link])
• Oxygenation adequate? If not, likely to need increased FiO2 (see
pp. [link]–[link]), or, if this is already maximal, need ventilatory support—involve ITU
• Is the CO2 low? If hyperventilation, already working hard breathing to maintain O2 at current level. May need to increase FiO2, or, if already maximal, need ventilatory assistance—involve ITU
• Is the CO2 high (see
p. [link])? Hypoventilating, tiring, or CO2 narcosis in COPD—consider ventilatory support
• Request an urgent portable CXR.
Circulation—
what is pulse rate, BP, rhythm on cardiac monitor/ECG? What is fluid balance status? Aim to optimize. Ensure IV access secured and blood tests sent. Look at BP, JVP, urine output, peripheral perfusion (capillary refill time). If they are hypotensive, are they underfilled? Consider fluids (crystalloid). If they are euvolaemic/overfilled, but hypotensive, with poor urine output, they may need inotropic support. Likely to need central venous access to enable CVP monitoring, and this will aid drug administration.
Disability—
Conscious level: GCS or AVPU (alert, responsive to verbal commands, responsive to pain, unresponsive). Are they confused? Check blood glucose, temperature, pupils, signs of acute neurological disease—neck stiffness, plantar reflexes, tone.
If known respiratory disease,
this will enable more targeted therapy. Try and obtain recent hospital notes. Ask patient or their relatives about disease severity, current treatment, plans of clinicians for long-term care (immunosuppression, transplant list, home non-invasive ventilation (NIV), advance directive, lasting power of attorney, etc.). What is their usual current health status—exercise tolerance, activities of daily living? What has caused this deterioration—a potentially reversible process (e.g. infection, drugs, pneumothorax, PE) or gradual progression of underlying disease? Review CXR, and compare with old films, if possible.
If no known respiratory disease,
full history required to obtain diagnosis. The patient’s cardiovascular status and illness severity will determine how brief/full this is. Ask about recent symptoms, travel, contact illness, risk factors for immunocompromise, usual health status, drugs.
For presentation-based differential diagnoses and initial investigation plans, see p. [link] (breathlessness),
p. [link] (chest pain),
p. [link] (haemoptysis),
p. [link] and p. [link] and
p. [link] (immunocompromise),
p. [link] (unexplained respiratory failure),
p. [link] (diffuse lung disease),
p. [link] (diffuse alveolar haemorrhage),
p. [link] (pleural effusion),
p. [link] (pregnancy),
p. [link] (post-operative),
p. [link] (pneumonia),
p. [link] (PE),
p. [link] (pneumothorax),
p. [link] (toxic agents),
pp. [link] and
pp. [link]–[link] (upper airway disease and anaphylaxis), and
pp. [link]–[link] (SVCO).
In patients with known severe respiratory disease,
with poor pre-morbid state (e.g. very limited exercise tolerance, comorbidities, severe dementia), intubation and invasive ventilation may not be appropriate. The patient may have their own views on this or have made a living will/advance directive. Old notes should be reviewed, if possible, and this decision should be discussed with their respiratory consultant or the consultant on call. NIV (see p. [link]) may be appropriate.
In patients with known respiratory disease,
with an acute exacerbation (infective or non-infective), respiratory and organ support may be indicated to enable them to survive this episode. This should be discussed with their respiratory consultant or the consultant on call and ITU.
In patients with no known respiratory disease,
respiratory and organ support may well be indicated to enable them to survive this episode. This should be discussed with the consultant on call and ITU. If they have significant pre-existing comorbidity from a non-respiratory disease (severe cardiac failure, severe dementia), the details of this should be ascertained and discussed with their usual consultant, if possible.
If there is any doubt about a patient’s usual health status, or no previous history or notes available, or they are deteriorating before full assessment can be made, they should be considered for full ventilatory and organ support.