Treatment of Severe Community-Acquired Pneumonia in Adults Without MRSA or P. aeruginosa Risk Factors
Adult inpatients presenting with severe community-acquired pneumonia who meet defined severity thresholds but carry no risk factors for MRSA or Pseudomonas aeruginosa represent a well-characterised subgroup with its own evidence-based treatment pathway.
Severe CAP defined by one major or three or more minor 2007 IDSA/ATS criteria, with no prior respiratory isolation of MRSA or P. aeruginosa and no recent hospitalisation with receipt of parenteral antibiotics in the preceding 90 days.
The protocol centres on intravenous combination antibiotic therapy: a beta-lactam agent is paired with one of two alternative antibiotic classes. The choice between the two combinations is graded by the strength of supporting evidence. Full agent selection and the complete regimen are in the structured protocol.
The target is clinical stability — resolution of vital sign abnormalities (heart rate, respiratory rate, blood pressure, oxygen saturation, temperature), ability to eat, and normal mentation — expected within 48 to 72 hours, with antibiotic therapy continued for no fewer than 5 days in total.
References
DOI: 10.1164/rccm.201908-1581ST- In inpatient adults with severe CAP (see Table 1) without risk factors for MRSA or P. aeruginosa, we recommend (Table 4) (note, specific agents and doses are the same as 9.1):
- a b-lactam plus a macrolide (strong recommendation, moderate quality of evidence); or
- a b-lactam plus a respiratory fluoroquinolone (strong recommendation, low quality of evidence).
- We recommend that the duration of antibiotic therapy should be guided by a validated measure of clinical stability (resolution of vital sign abnormalities [heart rate, respiratory rate, blood pressure, oxygen saturation, and temperature], ability to eat, and normal mentation), and antibiotic therapy should be continued until the patient achieves stability and for no less than a total of 5 days (strong recommendation, moderate quality of evidence).
- As most patients will achieve clinical stability within the first 48 to 72 hours, a total duration of therapy of 5 days will be appropriate for most patients.