Table 10.

Differences in the IDSA and ESCMID A. baumannii CR infections treatment recommendations. Adapted from Tamma et al. [163] and Carrara et al. [178]

IDSA	ESCMID
The use of high doses of ampicillin-sulbactam is recommended (6-9g/day) in combination with another antibiotic at least until clinical improvement is observed. Associate minocycline, tigecycline, polymyxin B or cefiderocol. do not associate fosfomycin, rifampicin or meropenem. It is recommended to use ampicillin-sulbactam, even if it is in-vitro resistant.	For patients with A. baumannii CR pneumonia sensitive to sulbactam, suggests ampicillin-sulbactam (Low level of evidence)
Consider the use of polymyxin B in combination with another antibiotic, because of limitations of this antibiotic: narrow therapeutic range, suboptimal pulmonary penetration, potential clinical failure, and emergency of resistance during treatment.	For patients with A. baumannii CR resistant to sulbactam, polymyxin or high doses of tigecycline are recommended if they are active in vitro. There is not enough evidence and a preferred antibiotic could not be recommended.
High doses of minocycline or tigecycline can be used with at less another antibiotic. Tigecycline is associated with higher mortality rates and should not be used in presence of bacteriemia.	We conditionally advise against the use of cefiderocol for treatment of infections caused by A. baumannii CR (low level of evidence).
Cefiderocol should be limited to the treatment of A. baumannii CR if other treatments fail, or it is resistant. It is recommended to prescribe it in combined treatment.	Neither combinations are recommended: polymyxin-meropenem (high level of evidence) nor polymyxin-rifampicin (moderate level of evidence).
The use of nebulized treatment is not recommended for respiratory infections.	In high risk and severe-ill patients, a combination of two antibiotics with in vitro activity among available therapies should be used: polymyxins, aminoglycosides, tigecycline, sulbactam. (very low level of evidence). If meropenem MIC is less than 8mg/L, combined therapy with meropenem extended infusion is suggested (good practice).