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Guidelineupdateforthemanagementofintravenouscatheterrelated 12639283169308-phpapp01
- 1. Guideline Update for the Management of Intravascular Catheter-Related Infections Sarah Nelson, Pharm.D. Critical Care Pharmacy Resident October 21 & 22, 2009
- 2. Objectives Identify common microorganisms associated with intravascular catheter-related infections Analyze treatment options for infections associated with short-term catheters Analyze treatment regimens for infections associated with long-term and dialysis catheters Recognize appropriate utilization of antibiotic lock therapy Summarize pathogen-specific treatment recommendations for select microorganisms
- 3. Background
- 4. Epidemiology 300 million catheters are used in the United States each year Functions of intravascular catheters include Administration of fluids and medications Administration of blood products Administration of total parenteral nutrition Monitor hemodynamic status Provide hemodialysis Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 5. Epidemiology Nosocomial CRBSI > Community-acquired CRBSI 21.6 cases of CRBSI per 1,000 hospital admissions Estimated case fatality rate of 20.6% ICU LOS increases by 9 to 11 days Edgeworth, J. J Hosp Infect. 2009;10:1-8 Al-Rawajfah OM, Stetzer F, Hweitt JB. Infect Control Hosp Epidemiol. 2009;30:000 Ramritu P, Halton K, Collignon P, et al. An J Infect Control. 2008;36:104-17
- 6. Types of Intravascular Devices Type Function Peripheral venous catheter Short-term intravascular administration Peripheral arterial catheter Monitor hemodynamics & blood gas Short-term central venous catheter (CVC) Short-term intravascular administration Pulmonary artery catheter Advanced hemodynamic monitoring Peripherally inserted central catheter (PICC) Short-term intravascular administration (alternative to a CVC) Long-term CVC Long-term tunneled vascular access Totally implantable device Long-term subcutaneous port/reservoir with needle access Mermel LA, Allon M, Bouza E, et al. Clin Infect Disease. 2009;49:1-45
- 8. Risk Factors for CRBSIs Type of intravascular device Intended use for catheter Insertion site Experience & education of installer Duration of catheter placement Characteristics of catheterized patient Utilization of preventative strategies Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 9. Diagnosis of CRBSI Catheter tip culture + blood culture Sonification of catheter Simultaneous quantitative blood cultures Differential time to positivity (DTP) Edgeworth, J. Intravascular catheter infections. J Hosp Infect. 2009;10:1-8
- 10. Common Pathogens Percutaneous Catheters Coagulase-negative staphlococci (CNS) Staphlococcus aureus Candida species Enteric gram-negative bacilli Surgically Implanted & Peripheral Catheters CNS Enteric gram-negative bacilli Staphlococcus aureus Pseudomonas aeurginosa Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 11. Lorente et al Design: prospective cohort Patient population: Medical/Surgical ICU pts with either a CVC or arterial catheter Outcome: assess proportion of CRBSI due to gram – rods and yeast according to catheter site Lorente L, Jimenez A, Santana M et al. Microorganisms responsible for intravascular catheter related bloodstream infection according to catheter site. Crit Care Med. 2007;35:2424-27
- 12. Lorente et al. Lorente L, Jimenez A, Santana M et al. Microorganisms responsible for intravascular catheter related bloodstream infection according to catheter site. Crit Care Med. 2007;35:2424-27 Femoral site n=36 Other site n=52 Gm + bacteria 16 47 CNS 8 29 MRSA 2 7 E. faecalis 4 2 Other 2 9 Gram – bacteria 14 4 E. coli 10 1 P. aeurginosa 1 2 Candida albicans 6 1
- 14. Empiric Antibiotic Selection Are antibiotics indicated? Signs/symptoms of infection Patient characteristics Where is the catheter located? Can/should the catheter be removed?
- 15. Catheter Removal Short-term CVC Not necessary unless: pt is severely ill, no other sources of fever identified, pt has secondary infections Long-term CVC/Port Not necessary unless complicated infection is apparent (tunnel infection, port abscess, secondary infections present) Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45 Rijnders BJ, Peetermans WE, Verwaest C et al. Watchful waiting vs. immediate catheter removal in ICU patients with suspected CRI: a randomized trial. Inten Care Med. 2004;30:1073-80
- 16. Empiric Antibiotic Therapy Gram + pathogen: Vancomycin is recommended Daptomycin if MRSA MIC consistently > 2 mcg/mL Gram – pathogen: Not always necessary Choice based off antibiogram and severity of illness Single agent vs. double coverage of P. aeurginosa Double coverage should be used if pt is neutropenic, severely ill with sepsis, or colonized with P. aeurginosa Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 17. Empiric Antifungals Not necessary unless patient is septic AND has any of the following: TPN Prolonged use of broad-spectrum antibiotics Malignancy Transplant recipient Femoral catheter in place Multi-site Candida colonizaton Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 18. Tailored Antibiotic Therapy Detailed summary of preferred antibiotics listed in guidelines Local antibiogram helps dictate tailored therapy Duration of therapy dictated by site of infection and pathogen isolated Day 1 of treatment is the first day on which a negative blood culture is obtained Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 20. Patient with a short term CVC or arterial line with acute febrile illness Mild or moderately ill (no hypotension or organ failure) Seriously ill (hypotension, hypoperfusion, s/sx organ dysfunction) Consider antimicrobial therapy Blood cultures (2 sets, 1 peripheral) If no other source of fever, remove CVC or AC and culture tip, replace or exchange CVC Blood cultures (2 sets, 1 peripheral), remove CVC or AC and culture tip, replace or exchange CVC Initiate appropriate antimicrobial therapy Blood culture (-) & catheter not cultured Blood culture (-) & catheter culture (-) Blood culture (-) & catheter culture ≥15 CFU Blood culture (+) & catheter culture ≥15 CFU Continued fever & no other source found, remove & culture CVC or AC Look for other source of infection See figure 2For S. aureus, treat for 5-7 days. For all other microbes, monitor for s/sx infection and send repeat blood cultures appropriately
- 21. Short-term CVC or AC-related bloodstream infection Complicated Uncomplicated (infection and fever resolved within 72 hours, no hardware, evidence of endocarditis or suppurative thrombophlebitis, & if S. aureus, no active malignancy or immunosuppression) Suppurative thrombophlebit is, endocarditis, osteomyelitis, etc S. aureus Enterococcus Gram - bacilli Candida spCNS Remove catheter & treat 4-6 weeks, 6-8 weeks for osteomyleitis Remove catheter and treat with systemic Abx for 5-7 days If catheter is retained, add ALT for 10-14 days Remove catheter and treat with systemic Abx for ≥ 14 days Remove catheter and treat with systemic Abx for 7- 14 days Remove catheter and treat with systemic Abx for 7- 14 days Remove catheter and treat with systemic Abx for ≥ 14 days after 1st negative culture
- 22. Long-term CVC or port-related bacteremia or fungemia UncomplicatedComplicated Tunnel infection/ port abscess Suppurative thrombophlebitis, endocarditis, osteomyelitis S. aureus Enterococcus Gram - bacilli Candida spCNS Remove CVC/P and treat with systemic Abx for 7- 10 days Remove CVC/P and treat with systemic Abx for 4-6 weeks, 6-8 weeks for osteomyelitis Retain CVC/P and treat with systemic Abx + ALT for 10-14 days Remove CVC/P and treat with systemic Abx for 4-6 weeks Retain CVC/P and treat with systemic Abx + ALT for 7-14 days Remove catheter and treat with systemic Abx for ≥ 14 days after 1st negative culture Remove and treat with systemic Abx 7-14 days OR Retain and treat with systemic + ALT for 10- 14 days Remove CVC/P if there is clinical deterioration, persisting bacteremia or signs of complicated infection
- 23. Tunneled HD catheter with suspected CRBSI Empiric Abx + ALT Negative blood cultures Persistent bacteremia/fungemia and fever Resolution of bacteremia/fungemia and fever in 2-3 days Stop Antibiotics CNS Gram - bacilli S. aureus C. albicans Remove CVC and administer antibiotics Antibiotic tx for 10- 14 days, retain CVC and continue ALT OR replace CVC Remove CVC & treat with systemic Abx for 3 weeks if TEE- Replace catheter and treat with systemic Abx for ≥ 14 days after 1st negative culture Systemic Abx 4-6 weeks and look for signs of complicated infection Persistent bacteremia/fungemia and fever Remove CVC and administer antibiotics Systemic Abx 4-6 weeks and look for signs of complicated infection
- 25. Changes to the 2009 Guidelines Short-term CVC Addition of arterial line infection Alteration of treatment duration Inclusion of antibiotic lock therapy Inclusion of specific therapy for Enterococcus sp. Long-term CVC Distinguishes hemodialysis catheter infection vs. long- term CVC and port infection Alteration of treatment duration Inclusion of antibiotic lock therapy Inclusion of specific therapy for Enterococcus sp. Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 26. Coagulase-negative staphylococcus Most common contaminant AND cause of CRBSI Benign clinical course Rarely leads to sepsis Little evidence to drive treatment recommendations Remove catheter & DO NOT treat Treat systemically and/or ABL Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 27. S. aureus Important to determine uncomplicated from complicated infection to determine treatment duration Infective endocarditis commonly associated with S. aureus bacteremia TEE should be completed 5-7 days after onset of bacteremia Risk factors associated with complicated S. aureus bacteremia: + blood cultures >72 hours after initiation of Abx Community-acquired infection Skin changes consistent with septic emboli Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 28. S. aureus Wilcox et al Design: randomized, double-blind, non-inferiority Intervention: Vancomyin (weight-based dosing) Linezolid 600 mg every 12 hours Endpoint: Microbiological and clinical cure Outcome: Microbiological cure: 86% for vancomycin vs. 81% for linezolid Clinical cure: 76% for vancomcyin vs. 79% for linezolid Wilcox MH, Tack KJ, Bouza E et al. Complicated skin and skin-structure infections and catheter-related bloodstream infections: non-inferiority of linezolid in a phase 3 study. Clin Infect Dis. 2009;48:203-12
- 29. Enterococcus sp. New addition to the guidelines Account for 10% of all nosocomial bloodstream infections 60% of E. faecalis was resistant to vancomycin No good data to support Role of combination therapy Duration of treatment Jones Rn, Marshall SA, Pfaller MA et al. Nosocomial enterococcal blood stream infections in the SCOPE program. Diagn Microbiol Infect Dis. 2004;39:309-17
- 30. Gram - bacilli Rate of gram – bacilli associated CRBSI is decreasing Resistance to gram – bacilli increasing Role of double antibiotic coverage for CRBSI Wilcox MH, Tack KJ, Bouza E et al. Complicated skin and skin-structure infections and catheter-related bloodstream infections: non-inferiority of linezolid in a phase 3 study. Clin Infect Dis. 2009;48:203-12
- 31. Gram - bacilli Safdar N et al. Design: meta-analysis Outcome: mortality in monotherapy vs. combination therapy in gram – bacteremia Results: Combination therapy for P. aeurginosa demonstrated a significant mortality benefit (OR 0.5, 95% CI 0.3-0.79) Mortality not reduced with utilization of combination therapy for other gram - bacilli Safdar N, Handelsman J, Maki D. Does combination antimicrobial therapy reduce mortality in gram-negative bacteremia? Lancet Infect Dis. 2004;4:519-27
- 33. Antibiotic Lock Therapy (ALT) Attempt to salvage current intravascular catheter Small amount of antibiotic is retained in the catheter lumen to eradicate colonized microorganisms Used in combination with systemic antibiotics for 7-14 days Segara-Newnham M, Martin-Cooper EM. Antibiotic Lock Technique: a review of the literature. Annals of Pharmacotherapy. 2005;39:311-8
- 34. Advantages of ALT Negligible risk of adverse effects Increased local concentration of antibiotic Ease of administration Ability to administer in an outpatient setting Decreases need for catheter replacement Cost-saving measure Segara-Newnham M, Martin-Cooper EM. Antibiotic Lock Technique: a review of the literature. Annals of Pharmacotherapy. 2005;39:311-8
- 35. Types of ALT Antibiotics Cefazolin, 5mg/mL Vancomycin, 5mg/mL Ampicillin, 10 mg/mL Ceftazidime, 0.5 mg/mL Ciprofloxacin, 0.2 mg/mL Gentamicin, 1 mg/mL Ethanol 70% Mermel LA, Allon M, Bouza E, et a. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the IDSA. Clin Infect Disease. 2009;49:1-45
- 36. Fernandez-Hidalgo et al. Design: retrospective/prospective Intervention Gram + organism: vancomycin 2 mg/mL Gram - organism: ciprofloxacin 2mg/mL OR amikacin 2 mg/mL Treatment duration: 10-14 days Outcomes Cure: negative cultures at 1 month Treatment failure: positive cultures or presence of fever >72 hours after start of ALT or expansion of infection Relapse: new episode of infection with same microorganism within 30 days of treatment completion Fernandez-Hidalgo N, Almirante B, Calleja R, et al. Antibiotic lock therapy for long-term intravascular catheter-related bacteremia: results of an open, non-comparative study. J Antimicro Chemotherapy. 2006:57:1172-80
- 37. Fernandez-Hidalgo et al. Organism No. of isolates Gram + organisms 80 CNS 56 S. aureus 20 E. faecalis 2 other 3 Gram – organisms 26 E. coli 11 P. aeurginosa 5 other 10 Polymicrobial infection 8 Fernandez-Hidalgo N, Almirante B, Calleja R, et al. Antibiotic lock therapy for long-term intravascular catheter-related bacteremia: results of an open, non-comparative study. J Antimicro Chemotherapy. 2006:57:1172-80
- 38. Fernandez-Hidalgo et al. Treatment success occurred in 93 cases (82%) Gram + infection cure rate: 78% Gram - infection cure rate: 92% By treatment day 7, all cultures were negative Unsuccessful outcomes occurred in 21 cases Treatment failure: 13 cases Relapses: 7 cases Death: 1 case Mean catheter salvage duration: 163 days Fernandez-Hidalgo N, Almirante B, Calleja R, et al. Antibiotic lock therapy for long-term intravascular catheter-related bacteremia: results of an open, non-comparative study. J Antimicro Chemotherapy. 2006:57:1172-80
- 39. Fortun et al. Design: prospective, randomized Intervention Systemic therapy alone Systemic therapy + ALT Gram + organism: vancomycin 2 mg/mL Gram - organism: ciprofloxacin 2mg/mL OR gentamicin 2 mg/mL Treatment duration: 14 days Outcomes Cure: negative cultures 2-5 days after completion of treatment and no colonization present Treatment failure: catheter removal, persistence of colonization, relapse of bacteremia Fortun J, Grill F, Martin-Davis, P. et al. Treatment of long-term intravascular catheter-related bacteremia with antibiotic lock therapy. J Antimricob Chemotherapy. 2006;58:816-821
- 40. Fortun et al. Organism ALT + systemic therapy N=19 Systemic therapy only N=29 CNS 14 19 S. aureus 3 4 Gram - bacteria 2 6 Fortun J, Grill F, Martin-Davis, P. et al. Treatment of long-term intravascular catheter-related bacteremia with antibiotic lock therapy. J Antimricob Chemotherapy. 2006;58:816-821
- 41. Fortun et al. Fortun J, Grill F, Martin-Davis, P. et al. Treatment of long-term intravascular catheter-related bacteremia with antibiotic lock therapy. J Antimricob Chemotherapy. 2006;58:816-821
- 42. Ethanol Locks Antiseptic agent, bactericidal Active against gram + and gram – organisms and fungi Non-toxic in doses administered Advantageous in patients with multi-drug resistant pathogens May be best option for PREVENTION of CRBSI and catheter colonization Broom J, Woods M, Allworth A. Ethanol lock therapy to treat tunnelled central venous catheter associated blood stream infections: results from a prospective trial. Scandinavian Journal of Infect Disesase. 2008;40:399-406
- 44. Preventative Strategies Hand hygiene Sterile precautions during insertion Skin antisepsis (chlorhexidine, iodine) Daily inspection and documentation of exit site Avoidance of femoral site utilization Removal of device as soon as it is no longer required Utilization of antimicrobial impregnated catheters Edgeworth, J. Intravascular catheter infections. J Hosp Infect. 2009;10:1-8
- 45. Antimicrobial Impregnated CVCs Coating of catheters with antimicrobial compounds External coating with chlorhexidine and silver sulfadiazine (CH-SS) Silver, platinum, or carbon coating Antimicrobial coatings minocycline + rifampin (MR) vancomycin cefazolin Only externally coated CH-SS and MR coated catheters reduced the risk of CRBSI as compared to uncoated catheters Ramritu P, Halton K, Collignon P, et al. A systematic review comparing the relative effectiveness of antimicrobial-coated catheters in intensive care units. An J Infect Control. 2008;36:104-17
- 46. Take Home Points CRBSI are common and can happen with a variety of intravascular devices CNS is the predominant pathogen causing CRBSI Pt characteristics may predispose them to other pathogens Catheter removal is not always necessary ‘Watch and wait’ method or antibiotic lock therapy may help avoid catheter replacement Antibiotic lock therapy plays a larger role in current guidelines Guidelines demonstrate proper treatment for short-term, long-term, tunneled, and port infections Prevention of CRBSI should not be forgotten
- 47. Questions?
Notas del editor
- Good afternoon. My name is Sarah Nelson. I am currently completing my critical care residency here at VCU. Today we are going to discuss the management of catheter related bloodstream infections. The guidelines, previously published in 2001, have recently been updated by the infectious disease society of America. We will spend the next 45 or so minutes on select areas of the guidelines, spending some time orienting ourselves to the devices themselves, the pathogens that are likely to be encountered, empiric antibiotic selection, and major updates, including treatment of hemodialysis catheters and antibiotic lock therapy as well as preventative strategies. We will end with a patient case to demonstrate our knowledge and understanding of the new guidelines.
- The objectives of this presentation are to: Identify common microorganisms associated with intravascular catheter-related infections Analyze treatment options for infections associated with short-term catheters Devise treatment regimens for infections associated with long-term and dialysis catheters Recognize appropriate utilization of antibiotic lock therapy
- To help orient ourselves with some background to better help us understand the guidelines.
- 300 million catheters are used yearly, of which 3 million are central venous catheters Venous catheters are primarily used for administration of fluids, medications, TPN, renal replacement therapies, and blood products. Arterial catheters are predominantly used for hemodynamic monitoring and collection of blood samples.
- Understanding catheter function and risks common to most ICU patients helps us understand why CRBSI are very common. A cross sectional study conducted by Omar Al-Raqajfah and colleagues used the US nationwide inpatient sample for the year 2003 to estimate the incidence and case-fatality rate associated with nosocomial BSI in the total US population. The sample set is a compilation of all inpatient community hospital stays from 994 hospitals in 37 states Cases were identified by ICD-9 code with the assumption that each patient could only have 1 CRBSI per admission. They found 185,824 patients with at least 1 code for BSI in the primary or secondary ICD-9 code fields. Of these patients, approximately 72,000 (39%) had community acquired BSI where the rest had acquired them on a hospital stay. Patients with nosocomial BSI had on average more procedures and comorbidities. Only 7% of the nosocomial infections were polymicrobial The most common pathogen was staph aureus in the nosocomial acquired BSI, whereas e. coli was the most common pathogen in patients with a documented community acquired BSI 21.6 cases of CRBSI per 1,000 hospital admissions Estimated case fatality rate of 20.6% Also, the rate of CRBSI in ICU patients rather than general floor patients as they have a greater likelihood of having and using a catheter for an extended duration of time, have more frequent manipulation of the catheter, have a higher likelihood of emergent catheter insertion such that aseptic technique is compromised, gerater underlying illness and more immunosuppression. This increases their LOS in an ICU. In this study, risk factors for nosocomial BSI were mechanical ventilation, CVC placement, TPN, peripheral or arterial line placement, other infections, or malnutrition
- This chart reviews various types of intravascular catheters that may be encountered in our patients. Peripheral Venous Access This is the typical "hospital IV" line put in your hand or forearm when you are admitted to the hospital. It is a short catheter, usually 3/4 to 1 inch long, inserted into a small peripheral vein and designed to be temporary An arterial line, or art-line, is a thin catheter inserted into an artery. It is most commonly used in intensive care medicine to monitor the blood pressure real-time (rather than by intermittent measurement), and to obtain samples for arterial blood gas measurements. It is not generally used to administer medication. An arterial line is usually inserted in the wrist (radial artery); but can also be inserted into the elbow (brachial artery), groin (femoral artery), foot (dorsalis pedis artery). Central venous catheter Pulmonary artery catheter Peripherally Inserted Central Catheters These catheters are centrally placed, meaning the tip ends up in the Superior Vena Cava. "Peripherally inserted" means it goes into your body near your elbow, in the brachial vein, and the tip is threaded up into your SVC. Two brand names for this type of catheter are Groshong and Intrasil Tunneled Central Catheters (long term central catheter) These catheter tips also end up in the Superior Vena Cava, but the other end is tunnelled about six inches away under the skin on the chest. On the catheter, inside this skin tunnel, is a Dacron cuff which your skin seals around, preventing bacteria from crawling along the outside of the catheter into the bloodstream. Two popular brand names of this type of catheter are Hickman and Groshong. Implanted Ports Implanted ports have all of the advantages of a central line except they are not always immediately available for use. A port is a small titanium reservoir with a rubber "stopper" that is attached to the catheter entering your vein below the collarbone. The whole thing is implanted under the skin in an outpatient procedure with local anesthesia and IV sedation.
- These are examples of central venous catheters. You can tell the are inserted centrally rather than peripherally as the portion which extends into the vein is not long. 3 catheters are shown here, a double lumen, single lumen and triple lumen catheter progressing from right to left across the screen. In a critical care setting, double and triple lumen catheters predominate as patients normally require multiple medications at the same time. Also, TPN requires a dedicated line. In the right hand corner is a device used to place a catheter. The same device can be used to replace a CVC if a CRBSI is suspected and there are no other sites available for placement of a new CVC.
- It is important to know who is at risk for acquiring a catheter related infection. The following is a short list of factors that have been associated with CRBSI.
- There are several ways to diagnosis a CRBSI. The first 2 methods listed require the removal of the catheter where as the second two methods do not. The latter methods are relatively new in the diagnosis of CRBSI but have good sensitivity and specificity for diagnosis while allowing the catheter to be retained if it is determined not to be the source of bacteremia. Catheter tip + blood culture: The catheter tip is rolled along an agar plate for colonization and a peripheral blood is obtained and plated for growth. If the same organism is isolated from both growth medias, and the quantity of organisms is >15 colonies from the catheter tip, a CRBSI can be diagnosed. This method is quick and cheap and has sensitivity and specificity of 85% and 82% respectively. Sonification of a catheter involved immersing the removed catheter in broth, applying sonification to release microorganisms held inside the catheter, and plating and quantifing catheter microorganism load. If >10^3 microorganisms are obtained, and correlate with a peripheral blood culture, a diagnosis can be made. Sensitivity and specificity of this method is 83% and 87% respectively Simultaneous quantitative blood culture diagnosis requires 2 blood culture be drawn, 1 through the catheter under suspect, the other via peripheral stick. If both cultures grow the same bacteria and the catheter culture has a five fold greater colony count than the peripheral blood culture, a diagnosis can be made. This technique has a 75% specificity and 97% sensitivity for short term catheters DTP is similar to the simultaneous blood culture method, however a diagnosis is made when the culture from the catheter grows bacteria 2 hours before the peripheral blood culture grows the same bacteria. This method as a sensitivity of 89% and specificity of 87% for short term catheters.
- So which organisms are we likely to see when diagnosing or identifying a CRBSI? It depends on the type and site of catheter. Coagulase-negative staphylococcus is the most common pathogen identified in all types of CRBSI.
- Lorente and colleagues had identified that, in previous studies, microorganisms which normally cause CRBSI have been clearly identified, however the rate at which each microorganism is likely to cause an infection at certain sites is not clearly identified. They set out to identify which patients are at higher risk for CRBSI due to GNR or yeast, which would perhaps alter their empiric antibiotics
- Pts were an average of 57 years of age, admitted for a cardiac surgery procedure, average apache II score of 17, with their catheter in place for 7 days prior to infection and ICU stay close to 2 weeks prior to infection Patients with a CRBSI originating from a femoral line experienced infection due to GNR or yeast significantly more than those with catheters inserted at other sites (mostly jugular and subclavian veins, 5 art lines).
- Empiric and tailored antibiotic therapy is important in the treatment of CRBSI. Empiric therapy should be chosen based on patient characteristics, but should always include vancomycin for gram + coverage (CNS, MRSA) in an ICU setting when the patient meets qualifications for likely having a nosocomial bloodstream infection. This is illustrated by a study completed by Ibrahim and colleagues who looked at 492 medical or surgical ICU patients being treated for a bloodstream infection. Of the 492 patients, 147, or 30%, received inappropriate antibiotic therapy. This translated into a mortality rate of 62%. This is compared to a mortality rate 28% for those treated correctly. Pathogens most likely to be mistreated include VRE, MRSA, candida, CNS, and pseudomonas aeurginosa.
- The selection of appropriate antibiotics is extremely important. As indicated by a study published in CHEST in 2000 looking at patients in a medical and surgical intensive care units, 61.9%, of patients whom received inappropriate antibiotics died whereas only 28.4% of those who received appropriate antibiotics, a difference which was statistically significant.
- The up to 91% of short term CVCs are removed for suspected CRBSI unnecessarily. Secondary infections: endocarditis, suppurative thrombophlebitis, osteomyleitis A study published in Intensive care medicine assessed whether ‘watchful waiting’ vs immediate removal and replacement of suspected infected catheter (ie. Source of unknown infection). Patients could not be neutropenic, have a documented bloodstream infection, have erythema, induration or purulence at the insertion site, or be hemodynamically unstable. They were randomized to 2 groups, the standard of care group, in which the catheter was immediately removed, or the investigational group, where the catheter was not removed unless blood cultures can back positive or the patient has persistent sepsis. 64 patients were included in the study. They found a 62% reduction in CVC removal when using the watchful waiting method and resolution of fever, duration of ICU stay and mortality did not differ between groups.
- Empiric antibiotic therapy is defined and suggested in the guidelines. It recommends . . .
- In the back of your handout there are enlarged flowcharts which are pulled from the guidelines. The changes to the guidelines are indicated with an arrow.
- Kaplan meier survival curves for the intention to treat population found no statistically significant difference between the 2 treatment groups among patients with s. aureus bacteremia. In fact, in patients were less likely to survive if treated with linezolid without documented bacteremia at baseline.
- The most common route of bacterial contaminatin in a long term catheter is through the hub, which supports the use of ALT. Fills the lumen of the catheter with antibiotic at concentrations 100-1000 fold higher than usual target concentrations and allowing it to dwell (lock) for a period of time while the catheter is not in order to sterilize it.
- Fernandex-Hidalgo and colleagues from Spain completed the largest published study looking at the effectiveness of ALT in CRBSI associated with long-term CVCs. They completed a retrospective study from 1996-2003, then transitioning to a propective study, mandating antibiotic selection and duration. Patients were excluded if they had a pocket, tunnel, or exit-site infection, had complications of CRBSI such as endocarditis or septic thrombophlebitis, candidemia, or hemodynamic instability at the time of diagnosis. CRBSI was defined as 2 positive cultures, with catheter culture growing 5-fold more CFU than the peripheral blood culture in the presence of signs/symptoms of infection They included 98 patients in their review. Most patients had access for the administration of chemotherapy, dialysis, or TPN and had tunneled catheters located in the jugular vein.
- On average, patients were treated with 12 days of systemic therapy and ALT. Treatment failure was often associated with gram + infection, with 8 pts having s. aureus, 4 CNS, 1 p. aeurginosa
- Fortun and colleagues further looked at the outcome when ALT was used with systemic therapy versus systemic therapy alone. Interventions and outcomes are similar to the previous study, with the exception of the use of gentamicin rather than amikacin, treating for 14 days total, and less stringent requirements for a successful outcome.
- They looked at a total of 48 patients. 19 whom received systemic plus ALT therapy and 29 who received systemic therapy alone. Patients were in their late 50s, required a long-term CVC for chemotherapy or administration of TPN
- Successful treatment was observed in 84% of episodes in the ALT group compared with 65% of episodes in the control group (P = 0.27). Specific analysis of CoNS episodes demonstrated that ALT cured 93% of them versus 79% in the control group (P = 0.36) The overall mortality was 16% and 24% in the study group and the control group, respectively. The attributable mortality was 5% in the ALT group (one patient with CoNS bacteraemia) and 7% in the control group