Step 2: Identify adults with CAP who may need intensive care support

Adults with any of the red flags in Red flags for intensive care support in adults with community-acquired pneumonia (CAP) are considered to have high-severity CAP.

Patients with high-severity CAP are at risk of acute organ failure and are usually managed in an intensive care unit because they are more likely to require intensive respiratory or vasopressor support. Always assess the patient’s suitability for intensive care management by establishing whether the patient has an advance care plan and considering the patient’s preferences and goals of care; see also Decision-making and ethical challenges in palliative care and Pneumonia in palliative care.

Figure 1. Red flags for intensive care support in adults with community-acquired pneumonia (CAP). Metlay, 2019

Patients with any of the following parameters may require intensive care support; assess the patient’s preferences, goals of care and suitability for intensive care management [NB1]:

  • signs of severe acute respiratory insufficiency
    • respiratory rate 30 breaths per minute or more
    • oxygen saturation less than 90% on room air, PaO2 less than 60 mmHg, or PaO2/FiO2 less than 250
    • multilobar or rapid progression of chest X-ray infiltrates
  • signs of acute extrapulmonary organ dysfunction
    • hypotension (systolic blood pressure less than 90 mmHg)
    • acute-onset confusion
    • poor peripheral perfusion or mottled skin
    • acute oliguria, elevated serum creatinine (above baseline) or uraemia (serum urea more than 7 mmol/L or BUN more than 19 mg/dL)
    • blood lactate concentration more than 2 mmol/L [NB2]Frenzen, 2018Kolditz, 2016.
Note:

BUN = blood urea nitrogen; FiO2 = fraction of oxygen in inspired air; PaO2 = partial pressure of oxygen

NB1: Many of the red flags are derived from formal pneumonia severity scoring tools. Based on the opinion of the Antibiotic Expert Group, some parameters are more conservative than the scoring tools to enable early identification of patients at risk of deterioration. Also consider if the patient has had a significant change from baseline.

NB2: Blood lactate can be measured using arterial or venous blood gas analysis. Venous blood gas analysis is acceptable for rapid lactate assessment (for further advice, see the Respiratory guidelines).

An increased respiratory rate (eg 30 breaths per minute or more) is an early predictor of respiratory failure, and together with hypoxaemia, may anticipate the need for mechanical ventilatory support. Blood lactate more than 2 mmol/L and systolic blood pressure less than 90 mmHg indicate circulatory failure and hypoperfusion, and impending need for inotropic support. Do not misattribute hypotension to hypovolaemia, which is rare in this clinical setting.

Monitor the patient for deterioration if there are other parameters that indicate a worse prognosis, such as:

  • unstable cardiac function
  • leucopenia
  • thrombocytopenia
  • acidosis (blood pH less than 7.35).

Consult local protocols or other references for comprehensive advice on nonantibiotic management of patients with sepsis or septic shock; see also Early intervention for sepsis or septic shock.