An 81-year-old man is transferred from a skilled nursing facility to the hospital due to lethargy and poor oral intake over the last 24 hours. For the past 2 days, he has had increased urinary frequency and dysuria. A urinalysis showed evidence of urinary tract infection, and he was started on oral ciprofloxacin. He was recently hospitalized with acute ischemic stroke, and his hospital course was complicated by pneumonia requiring intravenous antibiotics. He also had an episode of urinary retention requiring Foley catheter placement for 5 days. His other medical problems include mild cognitive impairment, hypertension, and type 2 diabetes mellitus. He has no known drug allergies.
His temperature is 38.9° C (102° F), blood pressure is 92/58 mm Hg, and pulse is 112/min. Lungs are clear to auscultation. His extremities are warm and well perfused.
Foley catheter placement yields 230 mL of cloudy urine.
Laboratory results are as follows:

Urine culture obtained at the nursing facility 2 days earlier showed extended spectrum beta-lactamase-producing Klebsiella.
Which of the following is the best initial antibiotic regimen for this patient?

Question

An 81-year-old man is transferred from a skilled nursing facility to the hospital due to lethargy and poor oral intake over the last 24 hours.  For the past 2 days, he has had increased urinary frequency and dysuria.  A urinalysis showed evidence of urinary tract infection, and he was started on oral ciprofloxacin.  He was recently hospitalized with acute ischemic stroke, and his hospital course was complicated by pneumonia requiring intravenous antibiotics.  He also had an episode of urinary retention requiring Foley catheter placement for 5 days.  His other medical problems include mild cognitive impairment, hypertension, and type 2 diabetes mellitus.  He has no known drug allergies.
His temperature is 38.9° C (102° F), blood pressure is 92/58 mm Hg, and pulse is 112/min.  Lungs are clear to auscultation.  His extremities are warm and well perfused.
Foley catheter placement yields 230 mL of cloudy urine.
Laboratory results are as follows:

Urine culture obtained at the nursing facility 2 days earlier showed extended spectrum beta-lactamase-producing Klebsiella.
Which of the following is the best initial antibiotic regimen for this patient?

Quizplus · Accepted Answer

Extended spectrum beta-lactamase (ESBL)-producing organisms lead to infections that result in increased virulence and mortality, longer hospital stays, and higher hospital expenses. Although ESBL-producing organisms are often the cause of nosocomial infections, community-acquired infections are becoming more common. Risk factors for acquiring ESBL-producing organisms include the following: Length of hospital or intensive care unit stay Presence of urinary catheter Presence of central venous or arterial catheters Presence of feeding tube Prior antibiotic administration Residence in long-term care facility (eg, nursing home) Ventilator usage Length of hospital or intensive care unit stay Presence of urinary catheter Presence of central venous or arterial catheters Presence of feeding tube Prior antibiotic administration Residence in long-term care facility (eg, nursing home) Ventilator usage Although ESBL-producing organisms may show in vitro susceptibility to penicillins with beta-lactamase inhibitors or cephalosporins, these drugs show an inoculum effect, resulting in decreased susceptibility as the size of inoculum is increased from 10⁵ to 10⁷ organisms. Similarly, treatment with fluoroquinolones, aminoglycosides, and aztreonam is also likely to fail due to higher resistance (Choices A, B, and D). Current guidelines recommended carbapenems (eg, imipenem, meropenem, doripenem, and ertapenem) for treating severe infections due to ESBL-producing organisms. Imipenem and meropenem have the best outcomes, but meropenem is preferred in this patient due to easier dose adjustment in renal failure. (Choice C) Daptomycin is used for treating skin and soft-tissue infections caused by Gram-positive organisms, Staphylococcus aureus (both methicillin-sensitive and methicillin-resistant) bacteremia and endocarditis, and vancomycin-resistant enterococci. It is not indicated for treatment in this patient, who has urosepsis due to Gram-negative organism. Educational objective: Although extended spectrum beta-lactamase-producing organisms may show in vitro susceptibility to penicillins with beta-lactamase inhibitors, cephalosporins, aminoglycosides, fluoroquinolones, and aztreonam, treatment with these agents is likely to result in high failure rates. Carbapenems (eg, imipenem, meropenem, doripenem, and ertapenem) are the only recommended treatment option for these organisms. __________ References: Epidemiology and genetic characteristics of extended-spectrum ß-lactamase-producing Gram-negative bacteria causing urinary tract infections in long-term care facilities. (http://www.ncbi.nlm.nih.gov/pubmed/22865381) Carbapenems versus alternative antibiotics for the treatment of bacteraemia due to Enterobacteriaceae producing extended-spectrum ß-lactamases: a systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/22915465)

An 81-Year-Old Man Is Transferred from a Skilled Nursing Facility