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Bacteria Bd Cultures
| Question | Answer |
|---|---|
| Bacteria in the blood ? | * Bacteremia |
| systemic inflammatory response syndrome, SIRS, has to have 2 out of what 4 conditions ? | * Temp >38oC --- Heart rate >90 beats/min --- Respirations >20 breaths/min --- WBC >12,000/cmm or with >10% bands (left shift) |
| SIRS due to an infection ? | * Sepsis |
| Sepsis associated with organ dysfunction, hypoperfusion, or hypotension ? | * Severe Sepsis |
| Persistent hypotension and perfusion abnormalities despite adequate fluid resuscitation ? | * Septic Shock |
| Altered organ function in acutely ill patient such that homeostasis cannot be maintained without intervention ? | * Multiple Organ Dysfunction Syndrome (MODS) |
| What is a left "shift" ? | * caused by the release of Neutrophils in response to bacteria |
| Process of someone having Organ Failure ? | * Bacterial infection --> Bacteremia --> Host inflammatory response --> Increased Inflammation & Coagulation/Decreased Fibrinolysis --> Changes in endothelium, microvasculature, BP --> Shock & Organ failure |
| Homeostasis and Sepsis ? | * The pathophysiology of sepsis includes the activation of inflammation, the activation of coagulation, and impairment of fibrinolysis......* this creates an imbalance in procoag and anticoag activity |
| Septic Shock and mortality ? | * Once septic shock has hit, mortality is very high |
| Pathophysiology of Bacteremia ? | * Primary focus of infection → lymphatics → vascular system |
| Some sources of Bacteremia ? | * Urinary tract --- Respiratory tract --- Intra-abdominal sites --- Abscesses and surgical wounds --- Intravascular devices ...... * Usu from Stap. Epi form our normal skin flora |
| Clinical Patterns of Bacteremia ? | * Transient - very common and cleared quickly, usu from defecating or brushing teeth ....... * Intermittent - subacute endocarditis or some abscesses .......* Continuous - acute endocarditis and some deep seated infections |
| Some things that predispose you to sepsis or septic shock ? | * Young/Old - Alteration in host defenses (spleen loss) - Severe underlying illnesses: DM/Cancer - Surgery - foreign bodies - RF requiring dialysis - Obstructive processes - Tmt w/ cytotoxic or antimetabolites - Loss of skin barrier |
| Common Septic agents today ? | * Staphylococcus aureus - Escherichia coli - Coag neg Staphylococcus - Klebsiella pneumoniae - Enterococcus sp. - Candida albicans - Pseudomonas aeruginosa - Streptococcus pneumoniae - Streptococcus viridans grp - Enterobacter cloacae |
| Agents it was back in the day ? | * E. Coli was 1st |
| Blood Culture Collection ? | * Collect after decontamination --- *Draw When Fever Peaks --- *Number of cultures: Acute sepsis: 2-3 blood cultures 30 min apart ....Subacute sepsis: 3 or more cultures over 1-2 days |
| Principles of Lab Detection ? | * need atleast 10ml of Bd..... * 1ml Bd to 10 ml broth ..... * Anticoagulant use: Sodium polyanetholsulfonate (SPS) .....* remove microbes |
| Blood Culture Systems: Traditional bottles and septi-check ? | * one is the old way, and the other attaches a medium to the top of the bottle and invert occasionally to see if anything grows |
| Blood Culture Systems: Lysis centrifugation and Automated Bactec 9000 ? | * Lysis: lysis RBCs to leave organism, and is good for YEASTS .... * Bactec = Detects growth by monitoring CO2 production, bye using different media bottles to grow different bacteria types |
| Detects growth by monitoring CO2 production ? | * Clorometric CO2 monitoring...newest way |
| Advantages to continuous blood monitoring systems ? | * Earlier detection time and less lab work time |
| Culture Interpretation ? | * Identify the Organism (contaminant or pathogen) ...... * Patterns of Positivity (repeat to rule out) .... * |
| False-positive rates of organisms that frequently represent contamination ? | * Coag neg Staph --- Corynebacterium spp --- Bacillus spp --- Propionibacterium acnes --- Viridans group Strep .............. * All due to contamination issues |
| Bd culture parameters ? | * best is one stick with multiple bottles, but hardly anyone does this |
| Who needs a Bd Culture ? | * Need 1 Major Criteria - suspected endocarditis, >39.4 temp (103), Vasc Cath. ...... * Or 2 Minor = Chills, Vomitting ,Fever 38.3-39.3C, Over 65yo, systolic BP <90, Cr > 2, > 18,000 WBC |
| Empiric Treatment ? | * start within 1 hr of suspicion, culture and then adjust.... * Cover broad spectrum for both G+ and - ....... * Vancomycin + Gram negative coverage |
| Factors leading to poor prognosis ? | * elderly -- see septic shock -- no febrile response -- underlying issues (cancer/DM/HTN) -- Enterococcal/G - etiology |
| Bd Culture Message ? | * Up to half of bd cultures are contaminated -- identify the organism can make it easier when see if it is contaminated or not -- repeated bd cultures show same organism -- contamination can be lowered by antiseptic use and well trained personel |