Infection/Sepsis Flashcards
the presence of a microbe in the human body without an inflammatory response
colonisation
inflammation due to a microbe
infection
the presence of a viable bacteria in the blood
bacteraemia
dysfunction caused by a dysregulated host response to infection
sepsis
is a subset of sepsis with circulatory and cellular/metabolic dysfunction associated with a higher risk of mortality
septic shock
general signs/symptoms of sepsis
local pain tenderness guarding blood PR in some systemic: fever chills or rigors nausea/vomiting constipation or diarrhoea malaise - anorexia
how does peritonitis occur
peritoneal cavity normally sterile, leakage of bowel contents results in peritonitis
what can peritonitis be secondary to
perforated duodenal ulcer, appendix, diverticulum, tumour
SOFA score
to assess for organ dysfunction due to sepsis (inc resp, cardio, renal dysfunctions)
qSOFA
assesses for mortality rather than diagnosis
what is the SIRS criteria
and what can it also be caused by?
temp >38 or <36 HR >90/min RR >20/min or PaCO2 <32mmhg WBC >12000 or <4000 when two or more criteria are present
trauma, burns, pancreatitis
pneumonia
UTI
how does infection lead to septic shock
colonisation -> infection -> SIRS (mortality 5-10%) -> sepsis -> septic shock
how is septic shock decided
sepsis plus signs of at least one acute organ dysfunction (renal, resp, hepatic, haematological, CNS, unexplained, CV- sepsis with hypotension refractory to adequate volume resuscitation
how is diagnosing infection done
microbiology, WCC, CRP, platelets/clotting
radiology
serology
PCR
what are the bacteraemia sources in the community
E. coli (urine, abdomen)
S.pneumoniae (resp)
s.aureus (usually MSSA - skin)
what are the bacteraemia sources in the hospital
E.coli ( catheter related or abdomen) S.aureus (usually MRSA- line or wound related) CNS (line/prosthesis related) Enterococci (urine, wound, line) Klebsiella (urine, wound) Pseudomonas spp,.
E. coli and similar organisms that inhabit the large bowel, such as Klebsiella sp., Proteus sp., Enterobacter sp.,
Serratia sp. etc.
coliforms
Organisms that grow better with oxygen, but can also grow without it, e.g. staphylococci, streptococci, enterococci and coliforms (i.e.the majority of human pathogens)
aerobic organisms
Organisms that require oxygen for growth, such as Pseudomonas sp.
strict aerobes
Organisms that WILL NOT grow in the presence of oxygen, such as Clostridium sp., Bacteroides sp., and anaerobic cocci
Present in large numbers in the large bowel
strict anaerobes
infection management
Antibiotic Management Supportive management : FLUIDS ANALGESIA NEED FOR SURGERY : EXPLORATION, INCISION-EXCISION AND DRAINAGE ETC VTE PROPHYLAXIS O2 CONTROL OF ELECTROLYTE BALANCE NEED FOR TRANSFUSION
what are the 9 steps in antimicrobial therapy of serious infections
- What is the likely source of infection and severity?
- Based on assessment of likely source most likely pathogen/s?
- Risk assessment of community vs healthcare acquired infection
- Risk assessment of likelihood of antibiotic resistance
- Bactericidal activity (some static drugs with good tissue penetration do well)
- Non-toxic, well-tolerated
- Route of administration: Parenteral administration, at least initially
- Duration. Usually 7-14 days – if complicated longer 4—6 weeks
- Low risk of C.difficile, especially in elderly patients
intra-abdominal treatment anaerobes
metronidazole
intra-abdominal treatment streptococci and enterococci
amoxicillin
intra-abdominal treatment aerobic coliforms
gentamicin
why is clindamycin avoided in intra-abdominal infections
risk of C. difficile infection
what would you treat for amoxicillin resistant strept, enterococci (RARE)
vancomycin
how are abscesses managed
large abscesses have no blood supply therefore antibiotic dont work well to penetrate skin, small ones can be treated with antibiotics but large need incision and drainage
symptoms of sepsis
are nonspecific:
-specific to an infectious source (eg, cough and dyspnea may suggest pneumonia, pain and purulent exudate in a surgical wound may suggest an underlying abscess).
- Arterial hypotension (eg, systolic blood pressure [SBP] <90 mmHg, mean arterial pressure [MAP] <70 mmHg, an SBP decrease >40 mmHg, or less than two standard deviations below normal for age). Because a sphygmomanometer may be unreliable in hypotensive patients, an arterial catheter may be needed
- Temperature >38.3 or <36ºC.
- Heart rate >90 beats/min or more than two standard deviations above the normal value for age.
- Tachypnea, respiratory rate >20 breaths/minute.
Signs of end-organ perfusion:
Warm, flushed skin may be present in the early phases of sepsis.
As sepsis progresses to shock, the skin may become cool due to redirection of blood flow to core organs. Decreased capillary refill, cyanosis, or mottling may indicate shock.
•Additional signs of hypoperfusion include altered mental status, obtundation or restlessness, and oliguria or anuria.
•Ileus or absent bowel sounds are often an end-stage sign of hypoperfusion.
There are no universally accepted criteria for individual organ dysfunction in MODS. However, progressive abnormalities of the following organ-specific parameters are commonly used to diagnose MODS and are also used in scoring systems to predict ICU mortality.
organ dysfunction signs are:
Respiratory – Partial pressure of arterial oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio
Haematology – Platelet count
Liver – Serum bilirubin
Renal – Serum creatinine (or urine output)
Brain – Glasgow coma score
Cardiovascular – Hypotension and vasopressor requirement
how is sepsis recognised in an emergency
central crushing chest!!!! pain
FAST
MES
>4 and SIRS
how do we treat sepsis?
recognised (NEWS), resuscitate with BUFALO, refer to consultant B - take blood cultures U - monitor urine output F - start IV fluid resuscitation A - give IV antibiotics L - check lactate O - given oxygen to target saturation
