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Nosocomial Infections

BASICS

DESCRIPTION

  • Health care " “associated infections (HAIs)
  • Infection must not have been present or incubating on admission to a health care facility.
  • CDC categories:Catheter-associated urinary tract infection (CAUTI)Surgical site infection (SSI)Ventilator-associated pneumonia (VAP)Central line " “associated bloodstream infection (CLABSI)Clostridium difficile infection (C. diff, C. difficile, CDAD, CDI)
  • The National Healthcare Safety Network (NHSN) at www.cdc.gov/nhsn monitors emerging HAI pathogens and their mechanisms of resistance to promote current prevention strategies.
  • Medicare and Medicaid will not pay for the treatment of certain HAI including CAUTIs, CLABSIs, and SSIs.

EPIDEMIOLOGY

  • General13/1,000 patient-days in the ICU (1)7/1,000 patient-days in high-risk nurseries2.6/1,000 patient-days in nurseries (1)Estimated cost of HAIs is $20 billion per year (2).
  • Infection specificCAUTIHospital stay increased by 1 to 3 days.Cost up to $600/infectionVAPHospital stay increased by 6 days.Cost up to $5,000/infectionCLABSIHospital stay increased by 7 to 20 days.Cost up to $56,000/infectionSSIHospital stay increased by 7.3 days.Cost >$3,000/infectionMay not be apparent until 1 month after surgeryC. difficile infection (see topic "Clostridium difficile Infection " ¯)

Incidence

  • 1 out of 25 inpatients in the United States has at least one HAI (3).722,000 HAIs in U.S. acute care hospitals in 2011 (3)UTI: 13% of HAIs (3)Pneumonia: 22% of HAIs (3)Bloodstream infection: 10% of HAIs (3)SSI: 22% of HAIs (3)107,000 C. difficile cases in 2011(4)[A]
  • Infections caused by gram-negative rods resistant to almost all antibiotics are increasing. Up to 70% of nosocomial infections are resistant to at least one previously active antimicrobial.

ETIOLOGY AND PATHOPHYSIOLOGY

  • Endogenous spread: Patient host flora causes invasive disease (most common).
  • Exogenous spread: Flora acquired from within health care facility.
  • Causative organismsUTI: Escherichia coli, Klebsiella spp., Serratia spp., Enterobacter, Pseudomonas aeruginosa, Enterococcus spp., Candida albicans (3)Pneumonia: aerobic gram-negative bacilli, Staphylococcus aureus, P. aeruginosa, Streptococcus spp. (3)Bloodstream infection: Staphylococcus spp., Candida spp., Enterococcus spp., gram-negative bacilli (3)SSI: S. aureus, gram-negative bacilli, Enterococcus spp., Streptococcus spp., Enterobacter spp., Bacteroides spp. (3)

RISK FACTORS

  • Extremes of age
  • Invasive surgical procedures (abdominal surgeries, orthopedic surgeries, urogynecologic surgeries, neurosurgery)
  • Use of indwelling medical devices.
  • Chronic disease (including diabetes, renal failure, and malignancy)
  • Immunodeficiency
  • Malnutrition
  • Medications (recent antibiotics, proton pump inhibitors, and sedatives)
  • Colonization with pathogenic strains of flora
  • Breakdown of mucosal/cutaneous barriers, including trauma and battle wounds
  • Anesthesia
  • Lack of attention to detail with universal precautions

GENERAL PREVENTION

  • Prevention should target both patient-specific and facility-related risk factors.
  • Hand hygiene " ”thoroughly wash hands (5)[C]On entering and leaving any patient room (5)After contact with blood, excretions, body fluids, wound dressings, nonintact skin, mucous membranes (5)Before using and after removing gloves (gloves are permeable to bacteria)When moving hands from contaminated to clean body site (5)Alcohol-based products are satisfactory when hands are not visibly soiled (5).Soap and water should be used when surfaces are visibly soiled or when contact with spores is anticipated.
  • Antibiotic stewardship " ”appropriate selection of antimicrobial therapy includes the following:Judicious use of antibiotics to reduce the emergence of multidrug-resistant organisms and the occurrence of C. difficile infection (2).Use of narrow-spectrum early-generation antibiotics when possible.Taking an antibiotic "time out " ¯ at 72 hours to review the patient 's clinical status and culture results, and eliminate ( "streamline " ¯) any redundant or unnecessary antibioticsUse shorter courses of antibiotics when appropriate.
  • Hospital-based surveillance programs and antibiograms
  • Infection control programs with specially trained employees (5)[C]
  • Employee education on HAIs (5)[C]
  • Disinfection of hospital rooms with hydrogen peroxide vapor or UV irradiation in addition to standard cleaning reduces environmental contamination and the risk of infection with multidrug-resistant organisms.
  • Minimize invasive procedures.
  • Caregiver stethoscope cleaningStethoscope bacterial contamination is common. Regular cleaning with alcohol-based preparations reduces bacterial load. Evidence is lacking to confirm whether stethoscope contamination causes nosocomial infections.
  • Isolation of known pathogen carriers (5)[A]Contact precautionsInstitute for known pathogens spread by direct contact including methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococcus (VRE), C. difficile, extended-spectrum ˇ ²-lactamase " “producing gram-negative rods, and carbapenemase-producing gram-negative rods.Glove when entering room (5)[B]Gown if clothing will touch patient or environment (5)[B]Droplet precautionsInfectious particles measure >5 ˇ ¼m.Institute for pathogens shed via talking, coughing, sneezing, mucosal shedding, airway suctioning, and bronchoscopy. These include Neisseria meningitidis, influenza, Haemophilus influenzae, Corynebacterium diphtheriae, and Bordetella pertussis.Mask when entering room (5)[B]Airborne precautionsInfectious particles measure <5 ˇ ¼m.Institute for pathogens shed via coughing including tuberculosis, varicella-zoster virus, and measles.Fit-tested National Institute of Occupational Safety and Health (NIOSH) " “approved ≥ N-95 respirator on entering room (5)[B]
  • Infection-specific measuresCAUTIEmployee education on urinary catheters (indications, placement, maintenance)Sterile catheter placement technique (6)[C]Closed urine collection system (6)[C]Use catheter only for necessary duration and remove as early as possible (6)[B].Use of nurse-driven protocols for guideline-driven catheter removal.Do not confuse catheter-associated asymptomatic bacteriuria with CAUTI.Do not screen for bacteriuria by routinely performing a urine culture when the catheter is withdrawn.VAPIntubate only when clinically necessary (7)[C]Perform oral decontamination with oral chlorhexidine (8)[A].Avoid nasotracheal intubation (7)[B].Inline suctioning (7)[C]Elevate head to 30 to 45 degrees (7)[C].CLABSIEducate staff about appropriate use of IV catheters (indications, placement, maintenance) (9)[A].Place catheters using sterile technique (including chlorhexidine prep and maximal barrier precautions) (9)[A].Use order "bundles " ¯ to improve adherence to catheter insertion guidelines.Remove catheter promptly when no longer clinically indicated (9)[A].Hand hygiene in addition to glove use (9)[A]Regularly monitor catheter site (9)[A].With introduction of these measures, CLASBI rates fell 46% between 2008 and 2011 (10)[A].SSIProper surgical hand hygiene (2)[B]Prophylactic antibiotic therapy when indicated (2)[A]; eliminate underlying infections before surgery if possible (2)[A].Remove hair with electric clippers/depilatory agent prior to incision (2)[B].Poor postoperative blood sugar control increases risk of infection.C. difficile infectionGloves combined with hand hygiene with soap and water (spores are resistant to alcohol-based products) (2)Restrict use of fluoroquinolones, cephalosporins, and clindamycin when possible (2).C. difficile is associated with the use of proton pump inhibitors: H2 blockers is preferred for acid suppression (11)[A].Probiotics may reduce nonspecific antibiotic-associated diarrhea; the effectiveness of probiotics for prevention of C. difficile is unclear (11).Bloodstream infectionsUse of chlorhexidine-impregnated washcloths to bathe ICU patients reduces bloodstream infections by 28% (12)[B].Routine surveillance for systemic inflammatory response syndrome (SIRS) using established criteria

DIAGNOSIS

Consistent with nature of infection ‚

HISTORY

  • Exposure to health care facility
  • Recent surgery/open wounds
  • History of invasive procedureUrinary catheter placementIndwelling vascular catheter
  • Recent intubation/mechanical ventilation
  • History of past infections (MRSA, VRE, etc.)

PHYSICAL EXAM

Consistent with nature of infection; site-specific exam for infections of skin, catheter sites, wounds, signs of sepsis, or pneumonia ‚

DIFFERENTIAL DIAGNOSIS

  • Community-acquired infection
  • Sepsis/SIRS
  • Other causes of infectious diarrhea

DIAGNOSTIC TESTS & INTERPRETATION

Specific to condition ‚

  • CBC, blood culture
  • Wound culture
  • Urine culture
  • Chest x-ray
  • Stool culture

Test Interpretation

Consistent with underlying infection ‚

TREATMENT

GENERAL MEASURES

  • Treat with appropriate antibiotics.
  • Order bundles improve adherence to sepsis guidelines and improves survival.
  • UTI: Remove urinary catheters.
  • CLABSI: Remove IV catheter.
  • C. difficile: Stop all antibiotics not being used to treat C. difficile infection.

MEDICATION

First Line

  • Targeted antimicrobial therapy
  • Several agents have been recently approved for the treatment of antibiotic-resistant infections and should be considered for second-line therapy.Daptomycin, telavancin, dalbavancin, ceftaroline, oritavancin, tedizolid, ceftolozane-tazobactam, and ceftazidime-avibactam

ISSUES FOR REFERRAL

  • Failure to respond to initial therapy
  • Some emerging resistant gram-negative infections are resistant to nearly all antibiotics and require expert consultation for management.

SURGERY/OTHER PROCEDURES

  • Screening for nasal carriage and isolation reduce the nosocomial spread of MRSA.
  • Treating proven nasal carriers of Staphylococcus or MRSA with mupirocin prevents S. aureus nosocomial infections after surgery, as long as the prevalence of mupirocin resistance is low (13)[B].

INPATIENT CONSIDERATIONS

IV Fluids

As needed for hemodynamic support ‚

Nursing

  • Hand washing should be performed on entering and exiting the patient room even when there is no direct contact with the patient.
  • Isolation precautions as indicated

Discharge Criteria

When infection has resolved or patient is stable and not an infectious risk ‚

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

Patient Monitoring

Risk for recurrence is generally low in immunocompetent patients. Manage underlying comorbidities (risk factors). ‚

PROGNOSIS

  • 99,000 deaths in 2002 in the United States (1)
  • Bloodstream infection mortality: 27%
  • Pneumonia mortality: 33 " “50%
  • SSI mortality: 11%

COMPLICATIONS

Related to specific nature of infection ‚

REFERENCES

11 Klevens ‚ RM, Edwards ‚ JR, Richards ‚ CLJr, et al. Estimating health care-associated infections and deaths in U.S. hospitals, 2002. Public Health Rep. 2007;122(2):160 " “166.22 Yokoe ‚ DS, Mermel ‚ LA, Anderson ‚ DJ, et al. A compendium of strategies to prevent healthcare-associated infections in acute care hospitals. Infect Control Hosp Epidemiol. 2008;29(Suppl 1):S12 " “S21.33 Magill ‚ SS, Edwards ‚ JR, Bamberg ‚ W, et al. Multistate point-prevalence survey of health care-associated infections. N Engl J Med. 2014;370(13):1198 " “1208.44 Lessa ‚ FC, Mu ‚ Y, Bamberg ‚ WM, et al. Burden of Clostridium difficile infection in the United States. N Engl J Med. 2015;372(9):825 " “834.55 Siegel ‚ JD, Rhinehart ‚ E, Jackson ‚ M, et al. 2007 guideline for isolation precautions: preventing transmission of infectious agents in health care settings. Am J Infect Control. 2007;35(10)(Suppl 2):S65 " “S164.66 Hooton ‚ TM, Bradley ‚ SF, Cardenas ‚ DD, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 international clinical practice guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(5):625 " “663.77 Tablan ‚ OC, Anderson ‚ LJ, Besser ‚ R, et al. Guidelines for preventing health-care associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR Recomm Rep. 2004;53(RR-3):1 " “36.88 Chan ‚ EY, Ruest ‚ A, Meade ‚ MO, et al. Oral decontamination for prevention of pneumonia in mechanically ventilated adults: systematic review and meta-analysis. BMJ. 2007;334(7599):889.99 O ' Grady ‚ NP, Alexander ‚ M, Burns ‚ LA, et al. 2011 Guidelines for the Prevention of Intravascular Catheter-Related Infections. www.cdc.gov/hicpac/BSI/01-BSI-guidelines-2011.html. Accessed 2011.1010 Centers for Disease Control and Prevention. 2013 National and State Healthcare-Associated Infections Progress Report. www.cdc.gov/hai/progress-report/index.html.1111 Surawicz ‚ CM, Brandt ‚ LJ, Binion ‚ DG, et al. Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections. Am J Gastroenterol. 2013;108(4):478 " “498.1212 Climo ‚ MW, Yokoe ‚ DS, Warren ‚ DK, et al. Effect of daily chlorhexidine bathing on hospital-acquired infection. N Engl J Med. 2013;368(6):533 " “542.1313 van Rijen ‚ M, Bonten ‚ M, Wenzel ‚ R, et al. Mupirocin ointment for preventing Staphylococcus aureus infections in nasal carriers. Cochrane Database Syst Rev. 2008;(4):CD006216.

CODES

ICD10

  • T83.51XA Infect/inflm reaction due to indwell urinary catheter, init
  • T81.4XXA Infection following a procedure, initial encounter
  • J95.851 Ventilator associated pneumonia
  • T82.7XXA Infect/inflm react d/t oth cardi/vasc dev/implnt/grft, init
  • N39.0 Urinary tract infection, site not specified

ICD9

  • 996.64 Infection and inflammatory reaction due to indwelling urinary catheter
  • 998.59 Other postoperative infection
  • 997.31 Ventilator associated pneumonia
  • 999.31 Other and unspecified infection due to central venous catheter
  • 599.0 Urinary tract infection, site not specified

SNOMED

  • 19168005 Nosocomial infectious disease (disorder)
  • 371061003 infection of bladder catheter (disorder)
  • 33910007 Postoperative infection (disorder)
  • 425464007 Nosocomial pneumonia (disorder)
  • 68566005 urinary tract infectious disease (disorder)
  • 431193003 Infection of bloodstream (disorder)

CLINICAL PEARLS

  • Nosocomial infections increase mortality, length of hospital stay, and cost of hospitalization.
  • Preventive efforts should address patient-specific and facility-related risk factors.
  • Proper hand hygiene, using an alcohol-based hand product or soap and water should be carried out before and after each patient encounter, even when gloves are used. Alcohol-based hand rubs are not effective for killing spores formed by C. difficile. Hand washing with soap and water is preferred in this situation.
  • Adherence to contact, droplet, or airborne precautions reduces the spread of infection.
  • The risk of developing a resistant nosocomial infection can be reduced by antibiotic streamlining, use of narrow-spectrum antibiotics, and frequent patient reevaluation to ensure the necessity of continuing antibiotics.