Consider referring a patient with suspected Legionnaires' disease to secondary care for further management if they present with features of severe community-acquired pneumonia, such as a CRB-65 score of 2 or more, or if clinical judgement indicates a more serious illness like cardiorespiratory failure or sepsis.
Referral should also be considered if symptoms are not improving as expected with antibiotics, if the patient is unable to take oral medication, or if there is bacterial resistance to oral antibiotics.
Additional factors influencing referral include oxygen saturation below 90% on room air, respiratory rate of 24 breaths per minute or more, heart rate over 100 beats per minute, systolic blood pressure 90 mmHg or less, abnormal mental status, or inability to eat without assistance.
Use clinical judgement alongside the CRB-65 score and consider the patient's wishes, social support, comorbidities, frailty, and pregnancy status when deciding on referral.
Urgent hospital admission is recommended for patients with a CRB-65 score of 3 or more.