culture grows vancomycin‐ resistant enterococcus (VRE). Blood cultures also grow 2/2 bottles with VRE. Which is the best choice of antibiotic to use?CefepimeLinezolidDaptomycinPiperacillin‐tazobactamMeropenemVancomycin‐resistant enterococci (VRE) was first reported in 1986 and cases have been increasing in the ICU. In 2006 in the US, the rate of VRE was 0.6 per 1000 admissions. There is an increased risk of mortality with VRE bacteremia and treatment should be started promptly. Effective treatments for VRE include quinupristin‐dalfopristin, linezolid, daptomycin, tigecycline, teicoplanin, and telavancin. Linezolid and daptomycin are the two most commonly used antibiotics in the US for VRE. Linezolid (Answer B) is an oxazolidone that binds to the 50S ribosomal subunit, has been approved by the FDA for VRE treatment, has better tissue penetration than other antibiotics, especially lung penetration, and is bacteriostatic. Linezolid can suppress bone marrow, is expensive, and can interact with psychiatric medications, particularly monoamine oxidase inhibitors (MAOIs). Daptomycin (Answer C) is a novel cyclic lipopeptide that inhibits DNA and RNA synthesis and is bactericidal. It is not approved by FDA for VRE infections, though it is recognized as an appropriate treatment for some VRE infections; however, it should not be used to treat pneumonia because it is inactivated by alveolar surfactant. Daptomycin may cause Clostridium difficile, rhabdomyolysis, and thrombocytopenia. A meta‐analysis showed linezolid treatment for VRE bacteremia had a lower mortality compared to daptomycin. Cefepime, piperacillin‐tazobactam, and meropenem are not indicated for VRE.Answer: BPrematunge C, MacDougall C, Johnstone J, et al. VRE and VSE bacteremia outcomes in the Era of effective VRE therapy: a systematic review and meta‐analysis. Infect Control Hosp Epidemiol. 2016; 37 (1):26–35.Chuang Y‐C, Wang J‐T, Lin H‐Y,et al. Daptomycin versus linezolid for treatment of vancomycin‐resistant enterococcal bacteremia: systematic review and meta‐analysis. BMC Infectious Diseases. 2014; 14 :687–695.Kalil AC, et al Management of adults with hospital‐acquired and ventilator‐associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016; 63 (5):e61–e111. PMID: 27418577.18 Which of the following is the best practice to prevent antibiotic resistance in the ICU?Initially treating a septic shock patient of unknown etiology with monotherapy quinolones.Continuing antibiotics for at least 7 days for intra‐abdominal sepsis after source control.Continuing vancomycin in a patient with ventilator‐associated pneumonia due to E. coli.De‐escalation of antibiotics based on culture results.Decrease the infusion time of intravenous antibiotics.Effective antimicrobial therapy is critical for the treatment of patients in the ICU and appropriate therapy decreases mortality as well as antibiotic resistance. The Surviving Sepsis campaign highlights starting antibiotics within an hour of emergency room admission or suspicion of sepsis and appropriate antimicrobial coverage of the suspected source. Sepsis of unknown origin requires active therapy against gram‐positive and gram‐negative pathogens. Common regimens are cefepime and vancomycin or piperacillin‐tazobactam and vancomycin. Quinolones only (Answer A) provide narrow coverage for gram‐negative bacteria and would not be appropriate for a septic patient of unknown origin. The Short Course Antimicrobial Therapy for Intraabdominal Infection (STOP‐IT) trial showed there was no difference in outcomes between 4 days and 8 days of antibiotics after source control had been achieved. Another study showed longer antibiotic courses led to increased risk of secondary infections and higher mortality. Answer B is incorrect because the patient only needs 4 days of antibiotics. It is important to de‐escalate antibiotics as soon as possible (Answer D). As vancomycin is used to cover gram‐positive bacteria, and specifically methicillin‐resistant Staph aureus (MRSA), vancomycin should be stopped as soon as it is known that the organism is not MRSA (Answer C). Answer E is incorrect because it is important to maintain minimum inhibitory concentration (MIC) of antibiotics. To achieve this, many beta‐lactamase antibiotics (cefepime, piperacillin) have been switched to extended infusions.Answer: DCampion M, Scully G . Antibiotic use in the intensive care unit: optimization and de‐escalation. J Intensive Care Med. 2018; 33 (12):647–655.
19 An 82‐year‐old man was started on clindamycin for left lower extremity cellulitis. Eight days after starting antibiotics, he presents to the emergency department with severe diarrhea, fever, abdominal pain, and emesis. His vitals are: HR 130 bpm, BP 90/50 mmHg, and his WBC is 35 000. C. difficile PCR is positive. What is the best management of his C. difficile infection?Discontinue antibiotics onlyDiscontinue antibiotics and start IV vancomycinDiscontinue antibiotics and start PO metronidazoleDiscontinue antibiotics and start PO vancomycinDiscontinue antibiotics and start IV rifampinClostridium difficile infection (CDI) has increased in frequency and severity over the last decade. Minimizing antibiotics, especially clindamycin and fluoroquinolones, is the cornerstone of prevention. This patient has severe C. difficile infection, as he presents in septic shock. Based on current treatment regimens, the previous antibiotics need to be stopped and vancomycin 125 mg orally four times a day should be started. Discontinuation of antibiotics only (Answer A) is incorrect as this patient needs additional treatment since he is in septic shock. Answer B is incorrect since vancomycin should be given via the oral (PO) route and not the IV route. Vancomycin administered IV does not reach therapeutic levels in the colonic lumen. Answer C is incorrect since oral metronidazole is only for mild disease or if oral vancomycin is unavailable or contraindicated. Metronidazole, administered either orally or IV, only reaches low therapeutic levels in the colon; therefore, even a slightly elevated MIC of C. difficile for metronidazole may lead to therapy failure. Multiple studies have shown that monotherapy of IV metronidazole is inferior to monotherapy PO vancomycin for treatment of Clostridium difficile. If the patient advances to fulminant colitis, the regimen would be vancomycin 500 mg orally or via nasogastric tube four times a day and metronidazole 500 mg intravenously every eight hours. Surgery would also be indicated with fulminant colitis. Rifampin (Answer E) is incorrect because while it has been used previously, data is lacking on its efficacy and is currently not recommended.Findoxamin, a novel macrolide antibiotic, bezlotoxumab, a monoclonocal antibody against toxin TCDB, and fecal microbiota transplant, are gaining popularity, especially in recurrent infections. Surgical treatment, typically a total colectomy, are reserved for those patients with fulminant colitis, though patient selection and timing of operation can be challenging.Answer: DGuh AY, Kutty PK . Clostridioides difficile infection. Ann Intern Med. 2018; 169 (7):ITC49–ITC64.Goldenberg JZ, Yap C, Lytvyn L, et al. Probiotics for the prevention of clostridium difficile‐ associated diarrhea in adults and children. The Cochrane Database of Systematic Reviews. 2017 Dec; 19(12):CD006095Bignardi GE . Risk factors for clostridium difficile infection. J Hosp Infect. 1998; 40(1):1–15. PMID: 9777516.Bowman JA, Uteer GH . Evolving strategies to manage clostridium difficile infections. J Gastrointest Surg. 2020; 24(2):484–91.
20 A 55‐year‐old otherwise healthy man presents to the emergency department with a large incarcerated umbilical hernia. He is brought to the operating room for open surgical repair. The patient was paralyzed with rocuronium to assist the reduction of the hernia. The surgery goes well and you tell the anesthesiologist that you are finished closing the fascia; however, a dose of rocuronium was just administered. Which statement is true regarding neuromuscular blocking agents (NMBAs) reversal?Neostigmine is an anticholinergic drug that is often used in conjunction with agents such as atropine and glycopyrrolate. The reversal agent available for succinylcholine is edrophonium.The mechanism of action of sugammadex includes chelating the NMBAs, making them inactive and removing them from the neuromuscular junction.Sugammadex is slower at reversing NMBA‐induced paralysis than both neostigmine and edrophonium.Acetylcholinesterase inhibitors are reversal agents available for depolarizing NMBAs.Neuromuscular blocking agents (NMBAs) can be broken down into two main classes: depolarizing and nondepolarizing agents. Succinylcholine is the only member of the depolarizing class of NMBAs and there is no reversal agent available (Answer B). The nondepolarizing NMBAs are rocuronium, pancuronium, vecuronium, atracurium, and its isomer, cisatracurium. Neostigmine and other acetylcholinesterase inhibitors (Answer A – incorrect choice because neostigmine is an acetylcholinesterase inhibitor) were the only reversal agents available for nondepolarizing NMBAs (Answer E). These agents increase the endogenous amount of acetylcholine available for binding at the neuromuscular junction, thus, competitively counteract the NMBAs effect. Sugammadex is a novel class of drugs called selective relaxant binding agents (SRBAs). The mechanism of action is twofold: (1) encapsulating (chelating) steroid backboned NMBAs (rocuronium,
