Is antipseudomonal antibiotic treatment needed for all nursing and healthcare-associated pneumonia patients at risk for antimicrobial resistance?

Objectives: Nursing and healthcare-associated pneumonia (NHCAP) was proposed by the Japanese Respiratory Society to refer to healthcare-associated pneumonia. This study aimed to investigate whether antipseudomonal antibiotic therapy improved the prognosis of NHCAP patients at high risk for antimicrobial-resistant pathogens.

Methods: Consecutive hospitalised NHCAP patients in Kurashiki Central Hospital between October 2010 and December 2016 were prospectively enrolled. NHCAP patients who were at high risk for antimicrobial resistance were defined as those who received antimicrobials in the preceding 90 days and/or were on tube feeding. The patients who received antipseudomonal antibiotics were defined as the guideline-concordant (GC) therapy group, and the others were defined as the guideline-discordant (GD) therapy group. The primary outcome was 30-day mortality. Inverse probability of treatment weighting (IPTW) analysis was used to reduce biases.

Results: There were 277 patients with NHCAP; a majority (78.0%) were discharged from a hospital in the preceding 90 days. There were 52 patients in the GC group and 225 patients in the GD group. The 30-day mortality rate was significantly higher in the GC group than in the GD group (17.3%, 9/52 vs. 7.1%, 16/225; P = 0.03). After IPTW analysis, the GC therapy, compared with GD therapy, did not improve the 30-day mortality (OR 1.71, 95% CI 0.65-4.47; P = 0.28).

Conclusions: Not all NHCAP patients, even those at high risk for antimicrobial resistance, need antipseudomonal antimicrobial treatment. The treatment strategy for NHCAP patients should be individualised, according to the pneumonia severity, risk for antimicrobial-resistant pathogens, and antibiogram in each hospital.