ICU · Antimicrobial Stewardship
Antimicrobial resistance in the ICU: mechanisms, organisms, and management
Also known as MDR organisms in ICU · VRE, ESBL, CRE, CPE · Antibiotic resistance · ESBL pneumonia · Carbapenem-resistant Enterobacterales · MRSA, VRE, CRPA, CRAB · Beta-lactamases — KPC, NDM, OXA-48 · Novel antibiotics for MDR Gram-negatives
Multidrug-resistant organisms in the ICU: standardised MDR/XDR/PDR category definitions, WHO critical-priority Gram-negatives, MERINO (meropenem over pip-tazo for ESBL bacteraemia), AUC-based vancomycin, daptomycin surfactant failure, aztreonam-avibactam first-line for NDM, TANGO-II/RESTORE-IMI/ASPECT-NP/CREDIBLE-CR/EPIC novel-agent trials, ESCMID precautions, time-to-effective-therapy survival, prolonged infusions, procalcitonin stopping and sulbactam-led Acinetobacter combinations.
Checked against its sources on 13 Oct 2026
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Red flags
- ESBL bacteraemia takes meropenem — pip-tazo failed noninferiority (12.3 vs 3.7 percent) and is not supported
- Daptomycin fails pneumonia via surfactant inhibition — linezolid matches vancomycin with less nephrotoxicity
- NDM takes aztreonam-avibactam first-line — halved mortality versus polymyxins (RR 0.51)
- Vancomycin AUC/MIC 400-600 replaces trough monitoring; vancomycin plus pip-tazo raises AKI (OR 1.57)
- Contact precautions per ESCMID — basic practices for all facilities, special approaches when transmission persists
Meet the patient
A man in his sixties is transferred to your ICU at 2am, ten days after repatriation from a three-week hospitalisation in New Delhi. He is in septic shock and now intubated — and blood cultures grow Klebsiella pneumoniae resistant to meropenem and multiple other classes. The carbapenemase PCR has been sent and is pending.[17]
The single question that decides whether this man lives is the one every CRE case turns on: what is the carbapenemase? Type it before you commit — KPC gets an avibactam partner, NDM gets aztreonam, and the wrong guess buys nothing but a dying patient and a phone call to infectious diseases. Hold that question and the rest of this topic falls into place.[17]
SAQ — Carbapenem-resistant Klebsiella pneumoniae bacteraemia in a repatriated patient
10 minutes · 10 marks
A 62-year-old man is admitted to ICU in septic shock 10 days after repatriation from a three-week hospitalisation in New Delhi for polytrauma. Blood cultures grow Klebsiella pneumoniae resistant to meropenem and multiple other classes; carbapenemase PCR has been sent and is pending.
SAQ — Vancomycin-resistant Enterococcus faecium (vanA VRE) bacteraemia with pneumonia
10 minutes · 10 marks
A 67-year-old man is day 14 of an ICU admission for necrotising pancreatitis with a central venous catheter, now febrile with rising lactate and purulent secretions. Blood cultures grow Enterococcus faecium resistant to vancomycin and ampicillin (vanA VRE), susceptible to linezolid and daptomycin. No vegetations on echo.
References31ShowHide
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