Lanny Hsieh, M.D. Infectious Diseases Hospitalist Program

Transcription

1 Lanny Hsieh, M.D. Infectious Diseases Hospitalist Program

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4 Definition of Fever Arbitrary (low grade may be significant in immunocompromised patients) > 38.5 (nurse will call you)

5 Be aware of signs of infection without fever Patient types: Immunocompromised Elderly Large burns or wounds On anti-inflammatory, immunosuppression, steroids. Signs: Hypothermia, rigors. Tachycardia Hypotension Tachypnea Confusion Oliguria Labs: lactic acidosis, leukopenia, leukocytosis, bandemia.

6 Blood cultures Sensitivity determined by many factors: Degree of bacteremia Antibiotics before culture Volume of blood drawn. Pediatric collection tubes should not be used for adults due to poor yield. Consider fungal blood culture if: Immunocompromised Prolonged hospitalization Indwelling lines Prolonged antibiotics.

7 If no lines, draw 2 sets of peripheral cultures. If indwelling lines, draw one set from line, one set periphery. If in ICU w multiple lines, send one set from each line and label source. No indication for TB or viral (CMV) blood cultures in routine fever workup.

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9 Lines and Fever

10 Intravascular Devices and Fever Relative risk of line infections by catheter: Quintons, CVL, art lines, PICC: 2-5 /1000 cath-days Implanted ports: per /1000 cath-days Peripheral IVs: <0.1 per 1000 catheter days Suspicion for line infection Abrupt onset of sepsis without obvious source. Difficulty drawing or infusing through a catheter. Exudate and/or erythema at exit site. Catheter tips should only be cultured if there is clinical suspicion for line infection. Empiric removal of lines is only indicated in septic, unstable patients.

11 Definitions of catheter-related infections Infection Definition Catheter colonization: Significant growth of an organism. Phlebitis: Induration, erythema, and tenderness along vein. Exit-site infection: Exudate, redness, induration at the catheter exit site. Tunnel infection: Tenderness, erythema, induration along subcutaneous tract of a tunneled catheter. Pocket infection: Infection in the subcutaneous pocket of a implanted intravascular device Bloodstream infection IDSA Guidelines for Intravascular Catheter-Related Infection CID 2009:49 (1 July)

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13 Phlebitis

14 Tunnel Infection

15 Pocket Infection

16 Diagnosis of Catheter-related Bacteremia Patient has an intravascular device. At least one positive peripheral blood culture. Clinical manifestations of infection (fever, chills, and/or hypotension). No apparent source for bacteremia other than the catheter. One of the following: Catheter tip (if removed) grew same organism as blood. OR Differential time to positivity IDSA Guidelines for Intravascular Catheter-Related Infection CID 2009:49 (1 July)

17 Most common pathogens isolated from bloodstream infections. Pathogen , % , % Coag neg staphylococci Staphylococcus aureus Enterococcus 8 13 Gram-negative rods E. coli 6 2 Enterobacter 5 5 P. aeruginosa 4 4 K. pneumoniae 4 3 Candida spp. 8 8 Prevention Guidelines for Catheter-Related Infections CID 2002:35 (1 December)

18 Short term catheter infection

19 Complicated = Remove 80. Duration of abx can be shorter (min 14d) if no DM, not immunosuppressed, catheter is removed, no intravascular device, no endocarditis on TEE, no thrombophlebitis on U/S, fever and bacteremia resolve in 72 hrs w abx, no evidence of metastatic infection.

20 Health Care Associated Pneumonia Cough, O2 sats, increased secretions. Immunocompromised patients may not have fever, cough, sputum, or leukocytosis. Physical exam, Chest Xray, sputum culture. Negative chest xray does NOT rule out pneumonia, especially in immunocompromised patients. Consider chest CT in certain patients. Positive sputum culture does NOT mean pneumonia. Most organisms can be colonizers as well as pathogens. Pleural effusions: only sample in certain patients. Not part of routine fever workup.

21 Empiric Antibiotics for Hospital acquired pneumonia? Presence of a new or progressive radiographic infiltrate plus at least 2 of: Fever greater than 38C leukocytosis or leukopenia Purulent secretions represent the most accurate clinical criteria for starting empiric antibiotic therapy. Am J Respir Crit Care Med Vol 171. pp , 2005 (ATS Guidelines)

22 RISK FACTORS FOR MULTIDRUG-RESISTANT PATHOGENS CAUSING HAP, HCAP, AND VAP. Virtually all of our patients fit in this category! Antimicrobial therapy within 3 months. Current hospitalization >5 days. High frequency of antibiotic resistance in the hospital. Hospitalization for >2 days in last 3 months. Nursing home resident. Home infusion therapy (including antibiotics). Dialysis within 30 days. Home wound care. Family member with MDR pathogen. Immunosuppressive disease and/or therapy. Am J Respir Crit Care Med Vol 171. pp , 2005

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24 INITIAL EMPIRIC THERAPY FOR HAP, VAP, HCAP IN PATIENTS WITH RISK FACTORS MDR PATHOGENS Potential Pathogens Streptococcus pneumoniae Haemophilus influenzae MSSA Enteric gram-negative bacilli MDR pathogens Pseudomonas aeruginosa MRSA ESBL Klebsiella pneumoniae and E. coli Acinetobacter species Am J Respir Crit Care Med Vol 171. pp , 2005

25 INITIAL EMPIRIC THERAPY FOR HAP, VAP, HCAP IN PATIENTS WITH LATE- ONSET DISEASE OR RISK FACTORS FOR MDR PATHOGENS. Antipseudomonal cephalosporin (cefepime, ceftazidime) or Antipseudomonal carbepenem (imipenem, meropenem) or B-Lactam/lactamase inhibitor (piperacillin tazobactam) plus Antipseudomonal fluoroquinolone (ciprofloxacin, levofloxacin) or Aminoglycoside (amikacin, gentamicin, tobramycin) plus Linezolid or vancomycin Am J Respir Crit Care Med Vol 171. pp , 2005

26 Is there advantage to empiric antibiotics? What if we waited for cultures?

27 Starting the right antibiotics in a timely manner ICU setting, teaching hospital, St. Louis. 107 consecutive pts w VAP. All 107 pts eventually appropriate antibiotics. 33 (31%) received abx that was delayed for >24 hr. 25 (76%) delay in writing abx orders. 6 received antibiotics not active against the resistant organism. 2 abx not given after order written. Mortality attributed to VAP: 13 (39%) in delay group compared to 8 (11%) in non-delay group. (P.001) Hospital mortality: 23 (70%) in delay group compared to 21 (28%) in non-delay group. (P<0.01) Chest Jul;122(1):262-8.

28 Urinary Tract Infections Catheter associated bacteriuria or candiduria: Usually colonization. Rarely symptomatic. Rarely a cause of fever or secondary sepsis unless: Urinary obstruction Recent urologic manipulation Neutropenic patient Kidney transplant patient Pyuria and bacteriuria count not reliable for infection. If patient is awake and alert, true infection should be symptomatic. When diagnosis is questionable, consider changing foley and recheck urine. If all parameters (pyuria, bacteruria, etc.) are better, then unlikely true infection.

29 Prevalence of asymptomatic bacteriuria in selected populations. Population Prevalence, % Healthy, premenopausal women Pregnant women Postmenopausal women aged years Diabetic patients Women Men Elderly persons in the community (age 70 yrs) Women Men Elderly persons in a long-term care facility Women Men Patients with indwelling catheter use Short-term 9 23 Long-term 100 IDSA Guidelines for Asymptomatic Bacteriuria CID 2005:40 (1 March)

30 Clostridium difficile colitis C. diff accounts for 20% 30% of abx-associated diarrhea and most common cause of infectious diarrhea in healthcare settings. Risk factors: age, length of hospitalization, antibiotics (duration and many abx), chemo, PPI (controversial). Manifestations: from asymptomatic to mild/moderate diarrhea, to fulminant pseudomembranous colitis. Bartlett JG. N Engl J Med 2002;346:

31 Fever, cramping, abdominal discomfort, and leukocytosis are common but found in fewer than half of patients. Suspected in pts w fever or leukocytosis and diarrhea who received antibiotics or chemo within last 60 days. Some patients may not have diarrhea: ileus or toxic megacolon. May occur w any antiobiotic, most common are clinda, FQ, and cephalosporins.

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33 C. difficile Diagnosis Testing for C. difficile or its toxins should be performed only on diarrheal (unformed) stool. EIA testing for toxin A and B is rapid but not sensitive. PCR testing appears to be rapid, but may be overly sensitive. May be picking up colonizers. 2-step method that uses antigen detection of glutamate dehydrogenase (GDH) and toxin as initial screening and then uses the cell cytotoxicity assay or toxigenic culture is preferred. Once confirmed, no utility in followup stool assays, follow clinically.

34 C. difficile Treatment Discontinue inciting antibiotics if possible. Severity criteria: age, WBC>15, creatinine 1.5x baseline Complications: hypotension, shock, ileus, megacolon. Metronidazole for the initial episode of mild-to-moderate CDI. Vancomycin for an initial episode of severe CDI. Dosage is 125 mg orally 4 times per day for days. Vancomycin orally with IV metronidazole for the treatment of severe, complicated CDI. Consider vancomycin enemas. Infection control and hospital epidemiology may 2010, vol. 31, no. 5

35 C. difficile Recurrence: ~25% Treatment of the first recurrence is with the same regimen as the initial episode but based on disease severity. Treatment of the second or later recurrence of CDI with po vancomycin therapy using a tapered and/or pulse regimen is the preferred next strategy. No recommendations regarding prevention of recurrent CDI in patients who require continued antibiotics for underlying infection. Fidaxomicin: cure rates similar to oral vanco. May be better at decreasing rate of recurrence. Better for bowel flora.

36 C. difficile: controversial strategies Probiotics: limited data to support, risk of bacteremia in immunosuppressed pts. Rifaximin chaser following oral vanco: caution, data shows increased MIC. Fecal transplants: success in case series. UCI GI division has research protocol in place. IVIG: no clear data to support.

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38 Other causes of diarrhea and fever? Lots of bacteria, viruses, parasites can cause diarrhea and fever, but these are community acquired. In immunocomprised patients (ie AIDS), can send stool studies for immunocompromised panel and ovum and parasite. These can reactivate due to acute illness.

39 Sinusitis Prevalence is low in comparison w other nosocomial infections. Risk factors: Most common: anatomic obstruction by nasal tubes. Maxillofacial trauma and retained blood clots. Etiological agents: Organisms that colonize the nasopharynx -- often polymicrobial. GNRs, including Pseudomonas aeruginosa (60%) S. aureus and coag negative staph (30%) Fungi (5-10%) Preferred diagnosis by CT scan of sinuses. If does not respond to empiric treatment, may need aspiration.

40 CNS infection and fever Nosocomial meningitis is rare in patients without immune compromise or CNS instrumentation. For patients with intracranial devices, need CSF sample: Ventriculostomy tubes Ommaya reservoirs May also need LP if suspect obstruction of CSF flow

41 Occult Sources of Infection Otitis media Decubitus ulcers Perineal or perianal abscesses Retained foreign bodies (tampons, contact lens) Intra-abdominal or pelvic abscesses. Septic thrombophlebitis Etc.

42 Drug Fever Any drug can cause fever. Most often attributed to: Antibiotics (beta-lactams) Anti-epileptic (phenytoin) Anti-arrhythmics (procanamide) Anti-hypertensives (methyldopa) Fevers may not occur immediately. One series, lag time between fever and drug administration was mean 21 days (median, 8) Fever often takes 1-3 days to resolve, but can take >7days after removing the offending agent. Rash occurs in small fraction of cases. Eosinophilia is uncommon.

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46 Drug-related Fevers Neuroleptic malignant syndrome Malignant hyperthermia Serotonin syndrome Drug withdrawl syndromes (alcohol, opiates, benzodiazepines)

47 Fevers not due to infection Acalculous cholecystitis Myocardial infarction Pulmonary emboli Stroke, especially intracranial bleed Pancreatitis Thyroid or adrenal disease Transplant rejection Tumor lysis syndrome Venous thrombosis Blood product transfusion Immune reconstitution inflammatory syndrome Etc

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49 Nurse tells me my patient is febrile, what should I do?

50 Approach to New Fever Check the other vital signs: low BP? Tachy? Tachypneic? O2 sats changed? Drop in urine output? Talk to the patient: any localizing symptoms? (cough, SOB, CP, diarrhea, headache, etc.) Physical exam: tender belly? Rhonchi? New murmur? Leg edema? Rash? Wounds? Diagnostics: blood cultures, lactate, UA and culture, CXR, EKG (if indicated), etc. Therapeutics: antibiotics, fluid resuscitation, etc.

51 Before starting empiric antibiotics What am I treating? How sick is patient? Immune status Resistance pattern community vs nosocomial Previous antibiotic exposure Antibiotic choice (last)

52 Some Common Scenarios

53 Fever 80 yo WM admitted from nursing home with altered mental status. Pt is somnolent, not much history could be obtained from patient or family. Nursing home staff reports possible aspiration event. PMH: HTN, DM, CAD. On exam T 39F, BP 90/60, P 120. Negative exam except for obtundation, bibasilar crackles, and chronic indwelling foley. CXR shows pulmonary edema. Labs: WBC 15. All other labs and cultures pending. Do you start antibiotics? If so, what?

54 What am I treating? Aspiration pneumonia, UTI. MRSA, pseudomonas, anaerobes, gram negatives. How sick is patient? Low BP, tachycardia, AMS severe sepsis = sick. Immune status Old, but otherwise not immunocompromised. Resistance pattern community vs nosocomial Previous abx exposure Nursing home = nosocomial, likely lots of abx exposure. Antibiotic choice Vancomycin + Meropenem (or equivalent) Don t forget Sepsis Resuscitation Bundle for this patient!!!

55 Fever 70 yo WF admitted 4 days ago for CHF exacerbation. Nurse calls you for fever to 39F. You see the patient, who is comfortably sitting in bed. She denies HA, cough, SOB, CP, nausea, vomiting, diarrhea, dysuria. No central lines, no foley. BP 130/70, P 80, O2 sat 97% on room air. Exam is normal except for bibasilar crackles. Urine and blood are sent for culture. CXR is ordered. Do you start antibiotics? If so, what?

56 What am I treating? No idea. How sick is patient? Not sick. Immune status Not immunocompromised. Resistance pattern community vs nosocomial Previous abx exposure Nosocomial. Antibiotic choice Hold off. Await culture results.

57 The End