Infection Flashcards
what are the different types of infection in surgical patients
3 types
1) superficial - an infection in the skin area only
2) deep - infection goes deeper than skin
3) organ - infection deep and involves organ
what are the patient risk factors in infection in the surgical patient
extremes of age poor nutritional state DM Renal failure smoking co-existing infection at other sites immunosuppression long post-operative stay
what are the operative risk factors in infection in the surgical patient
pre-op shaving length of operation foreign material in surgical site insertion of a surgical drain inadequate instrument sterilization poor closure of the wound post-op hypothermia post-op hematoma or lymphatic leak site of procedure
clinical features of infection in surgical pts
typically appear 3-7 days post-procedure - can take up to 3 weeks for prosthetic
surgical erythema
localised pain
pus/discharge from wound
wound dehiscence
unexplained persistent pyrexia
investigation for infection in a surgical patient?
wound swabs
bloods - FBC, U&E, CRP
blood cultures
if severe - BUFALO
what is the management of infection in a surgical patient?
ABX - using local guidelines to cover the most likely causative agent
removal of surgical sutures/clips
discharge of drainage of an pus
monitor closely
return to theatre if required for wash out
supportive care - analgesia and antipyrexial
what are some of the actions which can be carried out to prevent infection
hand decontamination
clean environment
sterile equipment
pre-op showering
hair removal
mechanical bowel prep
good diabetic control, smoking cessation, weight loss will all help to reduce infection risk
what is another name for glandular fever
infective mononucleosis or kissing disease
what is the main causative agent for infective mononucleosis
Epstein - Barr Virus - 90% of the time and it is most commonly spread through saliva ie kissing, sharing cups, toothbrushes, and other equipment that transmits saliva
which age group is most suspectable to infective mononucleosis
15-24 –> uni student esp freshers
clinical features of infective mononucleosis
the classic triad of fever, pharyngitis, and lymphadenopathy (general or cervical)
other symptoms incl –> fatigue, hepatitis, jaundice, myalgia, splenomegaly
macular rash in 10-20% of pts esp if treatment has started (ampicillin, amoxicillin etc)
investigation of infective monocuelosis
1) monospot test –> test for heterphil antibodies –> 60% +ve in 1st week, if -ve, repeat test in 7 days
2) FBC with blood film –> present of atypical lymphocytes
3) EBV specific antibodies if urgent test required
LFT
PCR
USS/CT abdo - splenomegaly/spleen rupture
differentials of infective mononucleosis
acute HIV infection Group A streptococcal pharyngitis Hep A Adenovirus Human herpes virus 6 CMV Herpes simplex virus -1
management of infective monoculceosis
acute - supportive
if upper airway obstruction due to pharyngitis / haemolytic anaemia - Prednisolone + admission
if Thrombocytopaenia -Prednisolone + IV Immunoglobulin
what is the definition of hospital-acquired pneumonia
pneumonia 48 hours after admission to hospital
what is the definition of ventilator-acquired pneumonia
pneumonia 48-72 hours after endotracheal intubation
what is the definition of hospital-acquired MRSA
MRSA 48 hours after admission to hospital
what is the definition of hospital-acquired C.Diff
occurs more than 3 days after admission to the hospital
what are some of the causative agents for HAP
usually aerobic gram -ve bacilli
Pseudomonas aerginsoa E.coli Klebsiella pneumonia Acinetobacter MSSA/MRSA Legionella- water supply Aspergillus- airvent.
what are some of the causative agents for VAP
Pseudomonas aerginosa E.coli Klebsiella Acinetobacter Staph A
what are some of the causative agents for catheter acquired UTI
E.coli
proteus mirabilis
Klebsiella
what is the causative pathogens for MRSA
methicillin-resistant staphylococcus aureus
Staphylococcus aureus
what are some risk factors for acquiring MRSA
chronic illness requiring healthcare visits
living in crowded condition/semi-closed communised
prior abx use
prex Hx MRSA
exposure to MRSA +ve people
what are the 4Cs for C.diff infection
Clindamycin
Co-amoxiclav
cephalosporin eg ceftriaxone, cefuroxime
ciprofloxacin
what is the causative pathogens for IV line infection
coagulase -ve staphylococci
staphylococci aureus
what are some of the clinical features of HAP/VAP
colonized by MDR bacteria
fever > 38 SOB productive cough chest pain fatigues
crackles maybe present hypoxia inc RR asymmetric chest expansion diminished resonance
what are some of the clinical features of catheter-associated UTI?
fever + rigors dysuria/polyuria/frequency N+V loin to groin pain fatigue
cloudy urine
foul smelling urine
haematuria
what are some of the clinical features of MRSA infection?
boils
abscess
cellulitis
impetigo
if bloodstream spread - secondary infection - pneumonia, UTI, septic arthritis, osteomyelitis
what are some of the clinical features of C.diff infection
Diarrhoea abdo pain fever N+V symptoms of shock if dehydrated/sepsis - hypotension and tachycardia
what are some of the clinical features of IV line infection
site of IV line - red, inflammed, tender to touch, hot, purulent, pain
fever
- blood infection = sepsis and so those with IV line infection should be treated seriously
what is the diagnostic criteria for HAP/VAP
2/3 of the following findings
1) fever > 38 degree
2) leucocytosis or leukopenia
3) purulent secretions
investigation for HAP/VAP?
bloods - FBC, U&E, CRP
CXR
culture of LRTI –> HAP (a protected brush specimen via bronchoscopy)
VAP culture –> endotracheal asipiration
ABG
investigation for catheter-associated UTI
urine dip initially/MSU culture
bloods - FBC, CRP
investigation for MRSA associated hospital infection
FBC blood culture urine culture tissue culture sputum culture Echo - indicated if new murmur and signs of endocarditis CXR - indicated if suspected pneumonia arthrocentesis fluid culture - indicated if evidence of joint effusion, pain or warmth
investigation for C-diff associated infection
FBC
Faecal occult blood - often positive
stool PCR
stool immunoassay for glutamate dehydrogenase (detect C.diff in bowel but no infection)
stool toxin A & B (+ve)
AXR - indicated if significant distension
investigation for IV line associated infection
FBC
CRP
blood culture
2x swab from access site
what are some differentials to C.diff colitis?
ABx associated diarrhea
ischaemic colitis
gastroenteritis
IBD
What are some risk factors to consider when managing HAP/VAO
1) ABx in th pre-ceding 90 days
2) septic shock at the time of VAP
3) ARDS preceding the VAP
4) current admission to hospital of > 5 days
5) acute renal replacement therapy prior to VAP onset
what are the managing plan after considering the risk factors of HAP/VAP?
Before culture results without RF: empirical abx
Before culture results with RF : empirical combination abx
After culture results: guided monoptherpay
what is the CPIS scoring system?
clinical pulmonary infection score - used for VAP only
used in day of diagnosis and day 3 for consideration of continuing Abx
management for catheter associated UTI?
change catheter if > 7 days
obtain urine sample
empirial abx
management for MRSA associated infection?
Skin and soft tissue: debridement including abscess incision and drainage and IV abx
Bacteremia, pneumonia, endocarditis: IV abx
UTI: oral abx (uncomplicated, IV (complicated)
Recurrent (bactericidal cleansing + nasal instillation of mupirocin)
management for C.diff associated infection?
Initial episode fulminant (sudden and severe)
- Vancomycin plus metronidazole or trugecycline or IVIG
- Discontinue causative agent
- Supportive care + infection control measures
Less severe 1st episode:
- oral vancomycin or fidaxomicin or metronidazole
- discontinuecauasative agent
- supportve care + infection control measures
First recurrence: repeat abx
Second recurrence repeat abx + faecal transplant.
management of IV line associated infection
remove device
empirial abx
sepsis - bufalo
what are the complications of C.diff
Ileus
peroration and peritonitis
toxic megacolon
what is the definition of pyrexia of unknown origin?
temp of > 38.3 lasting
more than 3 weeks
with no obvious source despite an investigation (3 days in the hospital or 3 episode of outpatients visit
infective causes of pyrexia of unknown origin
TB
intra-abdominal abscess
pelvic abscess
HIV in immunosuppressed pts
malignancy causes of pyrexia of unknown origin
leukemia
lymphoma
renal cell carcinoma
ant mets
autoimmune causes of pyrexia of unknown origin
IBD polyarthritis rheumatics temproal arteritis SLE Still's disease - rare autoimmune inflammatory disease
miscellaneous causes of pyrexia of unknown origin
drug induced fever hepatitis cirrhosis DVT sarcoidosis thyroid disease CNS disorder factious fever
emergency causes of pyrexia of unknown origin
immunocompromised or neutropenic sepsis
suspected GCA
red flags of pyrexia of unknown origin
fever + pattern of fever recent travel abroad to the TB affected area recent contact with animals/ets night sweats weight loss
system review required (Hx + Exam)
- CVS - chest pain, palpitations
- RVS - SOB, haemopytsis
- GI - abdo pain, N+V, diarrhoea
- Neuro - headaches, visual defects, sensory or motor deficit
investigation of pyrexia of unknown origin
temperature
basic obs - pulse, RR, BP, oxygen saturations
system review
- CVS - new murmur?
- RVS - RR
- GI - abdo tenderness, hepatoseplenomeglay
- Neuro - mainly hx
- lymphadenopathy - infection/malignancy
- rash or skin lesiosn - SLE, sarcoidosis, HIV, EBV
blood test - CRP, FBC, U&Es, LFT, TFT, blood cultures, skin TB test, CXR, rahs or palpable lymph node biopsy, MRI
imaging - CT abdo pelvis, serological testing
management of pyrexia of unknown origin
watchful wait approach = acceptable in a clinically stable pt for whom no diagnosis can be made after extensive investigation and prognosis is likely to be good
empirical abx for individuals who are clinically unstable or neutropenic
