Infections Flashcards
What are the SIRS criteria?
Have to have 2 or more of the following
Temperature >38.3 or 90bpm
RR >20
WBC count >12,000/mL or 10% immature neutrophils
What are the significance of super antigens?
Rather than stimulating specific T-lymphocytes, superantigens cause widespread stimulation of T-lymphocytes leading up to 20% of total T-lymphocyte activation
How would we describe Sepsis?
SIRS + Evidence of Infection
When does Sepsis become Severe Sepsis?
When it is associated with organ dysfunction
What are some of the signs of organ dysfuntion that you might look for in a septic patient?
Low BP
What are the SEPSIS SIX?
TAKE Blood Cultures, Check Lactate, Urine Output GIVE Antibiotics, IV Fluids and Oxygen WITHIN THE FIRST HOUR
Where should blood cultures be taken from?
Peripheral Venous Site
Plus from any indwelling device e.g. cannula, central and arterial lines.
How might a classical Pneumonia present?
Progressive cough and SOB over a short period of time Purulent Sputum Pleuritic Pain Haemoptysis Fever
Atypical Pneumonia’s tend to present differently, how might they present?
Vague flu like illness, headache, with a dry cough
Tend to present over weeks rather than days
What investigation would you do in a patient who presents with pneumonia?
CXR
Sputum and Blood Cultures
If atypical organism is likely - then serology for organsims such as legionella and mycoplasma should be requested along with urine samples to look for the relevant antigens
Describe the CURB-65 score for Pneumonia and what each score means in terms of the management of the patient?
Confusion >8 on AMTS
Urea >7mmol/L
Respiratory Rate > 30
Blood Pressure 65
0-1 = Managed in the community 2-3 = Managed on Ward 4-5 = Consider Intensive Care
How might a septic arthritis present?
Hot, swollen, red joint
Extremely tender
With a limited range of movement
What investigations should be done in a suspected septic arthritis?
Joint aspiration is vital to establish the diagnosis - aspirate should be sent for culture and mircoscopy
Blood cultures should also be sent
X-Rays to assess the amount of joint destruction
What is the management of septic arthritis?
Antibiotics - must cover staph and achieve good joint penetration
Liase with orthopaedic surgeons or rheumatologists
In severe cases joint wash out by arthroscopy is necessary
Physiotherapy is essential to recover joint function
What are the clinical signs of cellulitis?
Rapidly sreading erythema
Skin will feel hot and may be tender
May see blistering or skin necrosis in severe cases
In severe cases of cellulitis, what else should be examined?
Examine the nerves and vascular system in the area to check they are not compromised by compartment syndrome.
In a rapidly spreading cellulitis with destruction of underlying tissues, what diagnosis would you worry about?
Necrotising Fasciitis
How might an infected post-operative surgical wound present?
Pain
Erythema
Purulent Discharge
Heat around the incision
How might an anastomotic leak present in a patient who has had recent large bowel surgery.
Usually presents with an acute deterioration in a patient who initially made a good recovery - around 5-10 days after the operation
May get tachycardia, cardiac arryhtmia, no return of normal bowel function
What investigtions would you do in a patient who you suspect an anastomotic leak?
Bloods - WCC, CRP
Erect CXR - look for free air under the diaphragm (24-36 hours post-op)
Gastrografin Enema or contrast enhanced CT scan
What condition is associated with fever on the 4th day, if the starting day is counted as one?
Plasmodium Malariae
What condition is associated with fever on the third day, if the starting day is counted as one?
P.Ovale
P.Vixax
What fever is associated with a bradycardia?
Typhoid Fever
How might we define Pyrexia of Unknown Origin?
Illness lasting > 2 weeks
With fever > 38 on several occasions
No aetiology found after 3 days in hospital or 1 week as an outpatient.
What contacts do we give chemoprophylaxis too in meningitis patients?
Household contacts and kissing contacts
What form of chemoprophylaxis do we give for different causative agents?
Nisseria - ciproflaxacin stat dose
H.influenzae - rifampicin 4 days
Describe what normal CSF is like?
Opening pressure half serum level
WCC - no neutrophils and very low or no lymphocytes
Describe what CSF is like in bacterial mengingitis infection
Opening pressure +++ >30 Turbid/Cloudy Appearance Protein ++ >1 Glucose low Increased neutrophils
Describe what the CSF is like in a viral meningitis infection?
Opening pressure normal/slightly increased Normal clear appearance Protein slightly increased 0.5-1 Glucose - normal WCC increased lymphocytes
What virus is aciclovir used to treat?
Herpes Simplex
Whats the main differentiating clinical feature between meningitis and encephalitis?
In encephalitis you have an altered mental state. Including altered consciousness, convulsions and focal neurological signs
What forms of meningitis can you be vaccinated against?
Men C - now univesal childhood vaccination
Men A, C, W135 and Y if travelling to endemic areas
Current debate about Men B vaccine being introduced.
Which fungus looks like little eyes on india ink stain?
Cryptococcus Neoformans
List some of the common features of Legionella infection and what diagnostic test might you do?
Recent foreign travel Flu like symptoms Hyponatraemia Pleural Effusion Dx - urine antigen
