Lecture 2 - Signs, symptoms and Monitoring of Infection Flashcards
What are bacterial infections caused by?
Bacteria
What are viral infections caused by?
Viruses
What are fungal infections caused by?
Fungus
What are antibacterial agents not effective against?
viral or fungal infections
What helps guide best treatment?
determining the most likely cause of the infection
What to consider for diagnosis?
actual or presumes
best guess of diagnosis
clinical judgement
cultures available
Source?
likely organism
bacterial, viral, fungal
Why do we need cultures?
To tailor therapy to suit the patient and the infection
Signs and symptoms of an infection?
redness/changes in skin colour
pain
heat
swelling
loss of function
Clinical assessment of a patient?
temperature
tachycardia
tachypnoea (breathing rate)
white cell count
hypotension
hyperglycaemia
swollen lymph nodes
What is a high/low temperature?
High = 38 degrees +
Low = 36 degrees or lower
Normal white cell count?
between 4 and 11
Tachypnoea?
breathing rate more than 20 breaths per minute
What are clinical signs related to specific infections?
increased sputum volume/increased sputum purulence
pus/exudates
rashes
cough
pain on urination
nasal congestion
sore throat
SIRS criteria?
temperature <36 or >38
Pulse > 90bpm
respiratory rate > 20 breaths per minute
white cell count <4 or >11
Sepsis ?
One SIRS criteria + documented infection
What is a documented infection?
a host response to the presence of microorganisms or tissue invasion by microorganisms
Signs of a documented infection?
cellulitis
purulent sputum
X ray changes in the lung
redness
swelling
heat
Patient factors to consider?
age
other conditions/illness
nutritional status
compromised immune system
medications
Exogenous source of infection?
via host or from environment e.g. food, water, soil, coughing and sneezing
Endogenous source of infection?
normal flora from another part of the body e.g. skin pathogens, gut pathogens
What does the clinical diagnosis give?
‘best guess’
patients often treated for this as cultures can take days - weeks to come back from lab
What is taken before treatment?
samples from the site of infection e.g. blood cultures
Why must a sample be taken before treatment?
the bacterial level will lower after the patient has started treatment
What is done after sampling?
emperic/best guess treatment
most times you can’t wait for the outcome of cultures to start treatment
What happens when you get the culture and sensitivity results?
you can continue or modify the treatment
Blood cultures?
taken from different sites
must be taken while the patient is pyrexial
Sputum samples?
must get a good sample
Urine sample?
needs to be a mid stream sample as urine is usually sterile so need a good sampe
Swabs?
wounds, eyes, nose, throat
Other samples?
pus
bone samples
surgical samples
nail clippings
Bacteriological assessment?
agar plates
stains e.g. gram stain and zeihl-neelsen
confirmatory tests - oxidase/catalase
selective media
viral cultures
PCR
ELISA tests
What is sensitivity testing?
tests for sensitivity or resistance to a selection of potential treatments
What does sensitivity testing help?
guide the continuing therapy for treating the patient
national and local sensitivity patterns
guides the development of local formularies
What is the modified early warning system (MEWS)?
used in hospital to monitor the patient
the patient is given a score depending on the assessment
score of 4+ then the ward doctor is informed
score of 0 means no infection
SEWS?
surgical early warning system
modified for the surgical ward
score or 4 or more means contact doctor for review
score of 6 or more means urgent review needed
What are CRP and ESR?
c-reactive protein and erythrocyte sedimentation rate
they are non-specific markers of inflammation
What can CRP be used for?
to monitor how well a patient is reacting to antibacterial therapy
What is CURB-65?
assessment of pneumonia, a predictor of the outcome
CURB-65 scores?
the risk of death at 30 days increases as the score increases
0 = 0.6%
1 = 2.7%
3 = 14%
4 or 5 = 27.8%
CURB-65 score of 0?
low risk of death and do not normally require hospitilisation
CURB-65 score of 1 or 2?
increased risk of death, particularly score of 2
hospital referral and assessment should be considered
CURB-65 score of 3 or more?
high risk of death and require urgent hospital admission
What needs to be taken into account when deciding on home treatment?
the patients social circumstances and wishes
What are used for monitoring?
all diagnostic parameters
What does the frequency of monitoring depend on?
the severity of the infection
What does monitoring guide?
when to change route of therapy
when to stop therapy
when to change therapy
