Infectious Disease


9
Infectious Disease


Rathnayaka M. K. Gunasingha, MD1, Patrick Benoit, DO1, and Matthew J. Bradley, MD2


1 Walter Reed National Military Medical Center, Bethesda, MD, USA


2 Uniformed Services University of the Health Sciences, Program Director General Surgery Residency, Walter Reed National Military Medical Center, Bethesda, MD, USA



  1. A 28‐year‐old man is found by police obtunded with a respiratory rate of four per minute in a local park. He was administered naloxone in the field and transported to the hospital. On arrival, he continues to be lethargic with a blood pressure of 90/54 mm Hg, heart rate of 103/min, respiratory rate of 16/min, and temperature of 101.1o F. Physical exam reveals a 3cm × 3cm area of erythema, fluctuance, and induration in his left antecubital fossa as well as tender nodules on his fingertips. Auscultation of his chest reveals a blowing diastolic murmur. A transthoracic echocardiogram is negative for any signs of endocarditis. The next steps in the management of this patient including blood cultures, fluid resuscitation, and I & D of abscess should include:

    1. Transesophageal echocardiography, initiation of vancomycin
    2. Transesophageal echocardiography, initiation of vancomycin and piperacillin‐tazobactam
    3. Transesophageal echocardiography
    4. Metronidazole and piperacillin‐tazobactam
    5. Vancomycin and metronidazole

    This patient has 3 minor Modified Duke Criteria – (1) intravenous drug use, (2) fever > 100.4°F, and (3) Osler’s nodes – that indicate possible endocarditis. Intravenous drug use is a risk factor for acquisition of infective endocarditis. The patient should receive a transesophageal echo (TEE) to evaluate his cardiac valves even though the transthoracic echocardiogram was negative as TEE is more sensitive for cardiac vegetations. Staphylococcus aureus is the most common organism that causes infective endocarditis, followed by Viridans group Streptococci, coagulase‐negative Staphylococci, Enterococcus species, and Streptococcus bovis. Antibiotics should be started immediately after drawing blood cultures and should be broad to include MRSA coverage. Answer B is the correct choice as it provides broad‐spectrum coverage as well as the TEE that is needed after a negative TTE in this patient whose presentation is suspicious for infective endocarditis. Answer A adequately covers for MRSA, but without a known causative organism, more broad‐spectrum antibiotics should be initiated. Answer C is incorrect as it is critical that in cases of suspected endocarditis and sepsis that antibiotics be administered immediately after presentation. Answer D does not adequately cover against MRSA and is therefore incorrect. Answer E does not adequately cover gram‐negative bacteria and is therefore inadequate as initial therapy for this patient. It is a strong recommendation to consult Infectious Disease to determine the optimal empirical antibiotic treatment. The fluctuance and induration at the patient’s antecubital fossa indicate an abscess and must be drained as part of the treatment.

    Photos depict a patient with 3 minor Modified Duke Criteria.


    References for images:







































    Modified duke criteria
    Pathological criteria
    Positive histology or culture from pathological material obtained at autopsy or cardiac surgery
    Major criteria
    Two positive blood cultures with typical organism
    Persistent bacteremia
    Positive serology for Coxiella
    Positive echocardiogram


    1. Vegetation OR


    1. Abscess OR


    1. New regurgitation OR


    1. Dehiscence of prosthetic valves
    Minor criteria
    Predisposing heart disease or IVDA
    Fever > 38%
    Immunological phenomena
    Vascular phenomena
    Microbiological evidence not fitting major criteria

    Answer: B


    Galindo R . Osler’s nodes on hand. https://commons.wikimedia.org/wiki/File:Osler_Nodules_Hand.jpg. Published 2010. Accessed July 26, 2021.


    Galindo R . Osler spots on foot. https://commons.wikimedia.org/wiki/File:Osler_Spots_foot.jpg. Published 2010. Accessed July 26, 2021


    Baddour LM, Wilson WR, Bayer AS, et al. Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications: a scientific statement for healthcare professionals from the American Heart Association. Circulation. 2015; 132(15):1435–1486. doi:10.1161/CIR.0000000000000296


    Vogkou CT, Vlachogiannis NI, Palaiodimos L, et al. The causative agents in infective endocarditis: a systematic review comprising 33,214 cases. Eur J Clin Microbiol Infect Dis. 2016; 35(8):1227–1245. doi:10.1007/s10096‐016‐2660‐6


    Wang A, Gaca JG, Chu VH . Management considerations in infective endocarditis: a review. JAMA ‐ J Am Med Assoc. 2018; 320(1):72–83. doi:10.1001/jama.2018.75961.


    Miller SE, Maragakis LL . Central line‐associated bloodstream infection prevention. Curr Opin Infect Dis. 2012; 25(4):412–422. doi:10.1097/QCO.0b013e328355e4da


    Latif A, Halim MS, Pronovost PJ . Eliminating infections in the ICU: CLABSI. Curr Infect Dis Rep. 2015; 17(7). doi:10.1007/s11908‐015‐0491‐8


    Noto MJ, Domenico HJ, Byrne DW, et al. Chlorhexidine bathing and health care‐associated infections: a randomized clinical trial. JAMA ‐ J Am Med Assoc. 2015; 313(4):369–378. doi:10.1001/jama.2014.18400


  2. A 65‐year‐old man was admitted with acute pancreatitis and has been stable with intermittent tachycardia on the floor since his admission 2 days ago. Admission CT scan of the abdomen and pelvis showed edema and fat stranding around his pancreas. On the third day, he was noted to be more tachycardic, febrile with an increase of his leukocytosis. An interval CT scan demonstrates hypoattenuation of the pancreas, a large peri‐pancreatic retroperitoneal fluid collection with air and surrounding fat stranding. The next best course of treatment is:

    1. Start antibiotics with piperacillin‐tazobactam.
    2. Start antibiotics and percutaneously drain the collection.
    3. Start antibiotics and surgery for emergent necrosectomy.
    4. Start antifungals and percutaneously drain the collection.
    5. Continue current treatment with IV fluid resuscitation.

    This patient has infected necrotizing pancreatitis based on the physiologic and laboratory changes and new findings on CT scan. Broad‐spectrum antibiotics should be started since the fluid collection appears to be infected on clinical exam and on CT scan. In general, there is no indication to start antibiotics in necrotizing pancreatitis unless there is a culture‐proven infection or a strong suspicion for infection (gas in collection, sepsis, and clinical deterioration). Prophylactic antibiotics should not be used for sterile necrosis. For infected pancreatic necrosis, a multicenter trial showed that a minimally invasive step‐up approach (percutaneous drainage followed by minimal invasive retroperitoneal necrosectomy if needed) reduced major complications and death when compared to open necrosectomy. Answer A is incorrect because patient has indications for the need of drainage of the fluid collection. Answer C is not optimal as necrosectomy is now suggested to be reserved for failure of a step approach method. Answer D is incorrect because antifungals are not yet indicated. Answer E is incorrect because there is evidence of infection.


    Answer: B


    Da Costa DW, Boerma D, Van Santvoort HC, et al. Staged multidisciplinary step‐up management for necrotizing pancreatitis. Br J Surg. 2014; 101(1). doi:10.1002/bjs.9346


    Baron TH, DiMaio CJ, Wang AY, et al. American Gastroenterological Association Clinical Practice Update: Management of Pancreatic Necrosis. Gastroenterology. 2020; 158(1):67–75.e1. doi:10.1053/j.gastro.2019.07.064


    van Santvoort HC, Besselink MG, Bakker OJ, et al. A step‐up approach or open necrosectomy for necrotizing pancreatitis. N Engl J Med. 2010; 362(16):1491–1502. doi:10.1056/nejmoa0908821


  3. A 68‐year‐old woman was injured in MVC and had exploratory laparotomy, small bowel resection, and splenectomy. She is now three weeks post‐operative, and she has developed copious green fluid extruding from a newly opened wound on the superior aspect of her incision. Her abdomen is soft but exquisitely tender to palpation around the wound. A CT scan of the abdomen with oral contrast shows extravasation of the contrast through the abdominal wall. All of the following are important and necessary in the initial management of an enterocutaneous fistula except:

    1. Treatment and control of sepsis
    2. Fluid resuscitation
    3. Electrolyte repletion
    4. Effluent control and wound care
    5. Oral toleration of diet

    This patient has an enterocutaneous fistula, a very morbid complication after open surgery. Mortality is associated with sepsis, malnutrition, and fluid and electrolyte disturbances. It is important to control and treat sepsis as well as resuscitate the patient first. Effluent control and wound care are necessary to control output and prevent worsening and infection of any soft tissue wound. Nutrition is important for successful management of an EC fistula and can be a combination of enteral and parenteral, depending on nutritional needs and characteristics of the fistula. Oral toleration is not important initially and definitely not necessary. Characteristics of the fistula should be used to determine the appropriate nutrition source.


    Answer: E


    Evenson AR, Fischer JE . Current management of enterocutaneous fistula. J Gastrointest Surg. 2006; 10(3):455–464. doi:10.1016/j.gassur.2005.08.001


    Rosenthal MD, Brown CJ, Loftus TJ, et al. Nutritional management and strategies for the enterocutaneous fistula. Curr Surg Reports. 2020; 8(6):1–10. doi:10.1007/s40137‐020‐00255‐5


    Gribovskaja‐Rupp I, Melton GB . Enterocutaneous fistula: proven strategies and updates. Clin Colon Rectal Surg. 2016; 29(2):130–137. doi:10.1055/s‐0036‐1580732


  4. A 32‐year‐old man with HIV is brought to the hospital post‐ictal after a seizure while at home. He is now complaining of a stiff neck, nausea, and a constant headache. His temperature is 102.3°F, heart rate is 98, and blood pressure is 100/58. His ophthalmic exam reveals bilateral papilledema. What are the next steps for management after blood cultures, antibiotics, and fluids?

    1. Lumbar puncture and place an ICP monitor
    2. Dexamethasone and lumbar puncture
    3. Dexamethasone and obtain a CT scan of head
    4. CT scan of head and place an ICP monitor
    5. DCT scan of head and mannitol

    This immunocompromised patient has signs and symptoms concerning bacterial meningitis. After blood cultures and broad‐spectrum antibiotics are started, dexamethasone should be given to adult patients. A trial that evaluated outcomes in adult patients with bacterial meningitis found that negative outcomes, including death, were significantly lower in the group that received dexamethasone versus placebo; the group with streptococcus meningitis saw the most benefit. Hence, current recommendations state starting dexamethasone for any patients with possible streptococcal meningitis and continuing it only if culture results confirm the diagnosis. CT scan of the head should be obtained before a lumbar puncture since this patient has physical exam findings of elevated intracranial pressure (ICP), is immunocompromised, and had a new onset seizure within 1 week of presentation (choice A, B). There is a small (~1%) chance of herniation in adults with elevated ICP. A lumbar puncture is eventually necessary to identify the exact organism causing meningitis but is not done immediately (choice D). Mannitol may eventually be used to lower ICP prior to performing lumbar puncture. Initial empiric antimicrobial treatment for patients with suspected bacterial meningitis includes vancomycin in combination with either ceftriaxone or cefotaxime.


    Answer: C














































    Predisposing factor Common bacterial pathogens Antimicrobial therapy
    Age
    <1 month Streptococcus agalactiae, Escherichia coli, Listeria monocytogenes, Klebsiella species Ampicillin plus cefotaxime or ampicillin plus an aminoglycoside
    1–23 months Streptococcus pneumoniae, Neisseria meningitidis, S. agalactiae, Haemophilus influenzae, E. coli Vancomycin plus a third‐generation cephalosporina,b
    2–50 years N. meningitidis, 5. pneumoniae Vancomycin plus a third‐generation cephalosporina,b
    >50 years S. pneumoniae, N. meningitidis, L. monocytogenes, aerobic gram‐negative bacilli Vancomycin plus ampicillin plus a third‐generation cephalosporina,b
    Head trauma
    Basilar skull fracture S. pneumoniae, H. influenzae, group A β‐hemolytic streptococci Vancomycin plus a third‐generation cephalosporina
    Penetrating trauma Staphylococcus aureus, coagulase‐negative staphylococci (especially Staphylococcus epidermidis), aerobic gram‐negative bacilli (including Pseudomonas aeruginosa) Vancomycin plus cefepime, vancomycin plus ceftazidime, or vancomycin plus meropenem
    Postneurosurgery Aerobic gram‐negative bacilli (including P. aeruginosa), S. aureus, coagulase‐negative staphylococci (especially S. epidermidis) Vancomycin plus cefepime, vancomycin plus ceftazidime, or vancomycin plus meropenem
    CSF shunt Coagulase‐negative staphylococci (especially S. epidermidis), S. aureus, aerobic gram‐negative bacilli (including P. aeruginosa), Propionibacterium acnes Vancomycin plus cefepime,c vancomycin plus ceftazidime,c or vancomycin plus meropenemc

    a Ceftriaxone or cefotaxime.


    b Some experts would add rifampin if dexamethasone is also given.


    c In infants and children, vancomycin alone is reasonable unless Gram stains reveal the presence of gram‐negative bacilli.


    van de Beek D, de Gans J, Spanjaard L, et al. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med. 2004; 351(18):1849–1859. doi:10.1056/nejmoa040845


    Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004; 39(9):1267–1284. doi:10.1086/425368


    chart citation:


    Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004; 39(9):1267–1284. doi:10.1086/425368


  5. A 77‐year‐old woman is transferred to the ICU with increased work of breathing and desaturations. She was admitted to the hospital after sustaining multiple rib fractures from a ground‐level fall and was being treated for a hospital‐acquired lobar pneumonia. A new CT chest reveals a loculated pleural collection. Which of the following is not an appropriate antibiotic regimen?

    1. Gentamycin and metronidazole
    2. Vancomycin, cefepime, and metronidazole
    3. Vancomycin and piperacillin‐tazobactam
    4. Vancomycin and meropenem
    5. Linezolid and piperacillin‐tazobactam

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Dec 15, 2022 | Posted by in CRITICAL CARE | Comments Off on Infectious Disease

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