4) infection, MSK Flashcards
What is often given to patients during surgery to reduce the risk of post-op infections?
where to find further guidance on this?
normally give single dose of one or more ANTIBIOTICS just before or during surgery
which Abx are used depend on the type of surgery an local guidelines
check trust guidelines!!
Locations to look for infection on a post-op patient? 7
- peritonism (ie intra-abdo)
- wound infection
- cannula site infection
- chest infection
- UTI
- meningism
- endocarditis
PYREXIA in post-op patients:
- possible benign causes? 3
- investigations to consider? (5 bloods, 2 other, 3 imaging)
- what non-infection complication should you also check for? 1
MILD pyrexia in first 48hrs post-op may be from:
- atelectasis (needs prompt physio, not Abx)
- tissue damange / necrosis
- blood transfusion
HOWEVER have a low threshold for infection screen!!
- FBC
- U+E
(- LFT) - CRP
- blood cultures
- urine dip
(-MSU) - CXR
(- USS)
(- CT scan)
ALWAYS check for DVT!!!
- can cause a temp!
C. DIFF:
- what type of colitis does it cause?
- which CLASSES of antibiotics are highest risk? 3
- other risk factors? 6
pseudomembranous colitis (PMC)
CAUSATIVE ABX
- cephalosporins
- macrolides (esp clari)
- fluroquinolones (anything with ‘floxacin’ - eg ciprofloxacin)
“remember that often start with C for C diff”
- long hospital stay
- ITU stay
- NG tube
- elderly
- co-morbidities
- immnocompromised
SYMPTOMS of C. DIFF
- how long post-Abx do these tend to occur?
- main symptoms? 3
symptoms typically appear 5-10 DAYS post-Abx therapy
1) WATERY DIARRHOEA
- resolves 1-2 weeks post-Abx
- Varies from asymptomatic carrier (1-3% all adults)→ self limiting → severe + debilitating
- Can be BLOOD stained
2) COLICKY ABDO CRAMPS
3) FEVER w/ Rigors
INVESTIGATIONS for C. DIFF:
- bedside test to get? 1 (how many times?)
- important bloods to get? 4
1) STOOL SAMPLE (get 3!)
nb this is a stool cyto toxins test - some C Diff produce toxins, others don’t - can also do culture and other fancy tests! - ask micro!
- FBC (↑↑WCC – 80%, often v.high),
- ↑↑CRP
- ↓Albumin (inf/sepsis/protein losing enteropathy)
- U+Es – essential to determine electrolyte loss
nb consider colonoscopy w biopsy if really severe!! (or think may be a DDx)
C. DIFF:
- approach if pt critically unwell?
- antibiotic options? 2 (incl route)
- additional supportive / nursing management that should also always do? 4
A-E approach
1st) ORAL METRONIDAZOLE
2nd) ORAL VANCOMYCIN
nb only indication for oral vancomycin!
nb use both if severe!
nb if asymptomatic may not need abx!
1) STOP causative abx!
2) put pt in side room
3) give fluids (PO + IV) to replace losses
4) inform public health england!!
nb Adjuvant pro-biotics, IV immunoglobulin or rifampacin used in refractory or recurrent C.diff (also Faecal transplant - Colectomy if Toxic megacolon)
DDx for C Diff? 4 (ie watery diarrhoea)
- side effect of Abx (esp macrolides)
- IBD
- food poisoning
- typhoid etc (always askl Travel Hx)
Which Abx is given to treat MRSA? 1
Vancomycin
HIV
- four main stages of infection? (just name them - do descriptions on later flashcards)
stage 1 = SEROCONVERSION
HIV:
- how long take to become established in body post-exposure?
- time scale of seroconversion?
- 3 main presentations of seroconversion?
48-72 hours to become established in body post-exposure
SERO CONVERSION
- transient illness 2-6 weeks after exposure
1) FLU-LIKE symptoms
- headache, fever, malaise, myalgia, pharyngitis
2) EXACERBATION of CHRONIC inflamm conditions
- eg eczema, mouth ulcers, lymphadenopathy
3) MACULOPAPULAR RASH on TRUNK
nb can rarely get meningoencephalitis too
HIV:
- typical presentation of clinical latency?
- what may some patients have? 1
after initially seroconversion illness, pts are normally ASYMPTOMATIC for a period
30% will have persistent generalised LYMPHADENOPATHY (PGL)
- nb this is nodes >1cm for >3 months
HIV: AIRDS related complex (ARC)
- what is it considered as?
- possible systemic symptoms? 4
- common opportunistic infections/conditions? 10
AIDS related complex (ARC) = ↓CD4 + ↑HIV viral load
Regarded as a prodrome to AIDS
SYSTEMIC
- fever
- night sweats
- DIARRHOEA
- weight loss
OPPORTUNISTIC INFECTIONS
- TB (most common)
- candida (norm oesophagus)
- EBV
- shingles
- atypical pneumonia (incl; pneumocystis)
- cryptococcal meningitis
- toxoplasmosis
- kaposi’s sarcoma
- invasive cervical cancer
- lymphoma
Stage 4 of HIV infection
- aka?
- prognosis if no HAART?
aka AIDs (although this name is going out of favour dt stigma! - say serious HIV infection etc)
2 years prognosis if no HAART
What 3 conditions are associated with HIV and should consider testing for HIV if someone presents with them? 3
- Syphilis
- EBV
- TB
Who should have a HIV test? 8
- Anyone who requests it
- All registering in GP where prevalence exceeds 2/1000
- Sexual intercourse w/ person from high risk country (Africa, middle east, Caribbean)
- Sexual partner w/ HIV +ve person
- Homosexual men or MSM
- IVDU
- Anyone with STI
- Anyone with suspicion of HIV as differential
HIV testing:
- 2 types of point of care tests? 2
- window period for antigen test?
- window period for antibody test?
POCT
- self-sampling (blood or saliva)
- rapid test kit (30 mins)
HIV antigen
- use 2-4 weeks after exposure
HIV antibody
- can use if >4weeks post-exposure
If someone is HIV positive, other things to consider testsing for? 7
TB
Hep B+C
Tocoplasma
CMV
Syphilis
other STIs
Management of HIV:
- mainstay of treatment? 1
- what should be monitored? 1
- how to prevent opportunistic infections? 2
Highly active anti-retroviral therapy (HAART)
monitor viral load, CD4 count AND FBC every 3 months
- nb do other routine blood tests every 6 months
prevent:
- vaccines (pneumococcal, fluy, hepatitis, tetanus)
- prophylactic antivirals and/or antibiotics (if CD4 count is below certain level)
HIV positive mothers:
- how to reduce risk of transmission to baby?
- vaginal birth or c-section?
- breast or bottle feeding?
Suppress mums viral load with HAART
Measure viral load @ 36wk
Can have normal vaginal delivery if VL suppressed (<50 copies/ml @ 36 wks)
May require C-Section
Neonate PEP for 4 wks
Avoidance of breast feeding
nb if do all this risk drops from 45% to <1%
When can give PEP to avoid sero-conversion?
within 72 hours of exposure
INFLUENZA:
- when is a person with flu infective from and to?
infective from 1 day before symptoms to 7 days after symptoms end
INFLUENZA:
- main symptoms? 7
Fever
Headache
Malaise
↓Mood
Myalgia
Nausea and Vomiting
Conjunctivitis, eye pain – conjunctivitis ± photophobia
INFLUENZA:
- which four broad groups most at risk of complications? 4
Chronic resp disease – COPD, bronchiectasis, CF, interstitial lung fibrosis, asthma
Chronic heart disease – congenital, HF, IHD
CKD or CLD or DM
Immunosuppression
BASICALLY any serious chronic disease or immunosuppression!
INFLUENZA:
- two main tests? (which norm done)
- when done?
- serious DDx which it can be mistaken for? 1
PCR – 36hrs
Nasopharyngeal swab culture – takes 1 wk
test if unwell in hospital or unclear over diagnosis
can mimic MENINGITIS with fever, phtophobia, generally unwell etc (also Covid….)
INFLUENZA:
- symptomatic medication to advise for everyone? 1
- who can consider giving antivirals to? when to give them?
PARACETAMOL for all!
(also fluids and bed rest)
Antivirals – Oseltamivir – if ALL of the following apply
1) Person is an at risk group
2) National surveillance scheme indicates flu is circularting
3) Person can start Rx within 48hrs of Sx onset
MUMPS:
- type of virus?
- prevention? (when?)
highly infectious RNA Paramyxovirus illness spreads via droplet infection
MMR vaccine
- 1 year
- 3 years 4 months
MUMPS
- symptoms of prodrome? 3
- main feature? 1 (+ 4 associated symptoms)
- how diagnose? 1
PRODROME
- Fever
- malaise
- myalgia
PAROTITIS
– swelling of parotid glands begins U/L → B/L
- Painful swelling
- causes ear ache or pain whilst eating
- Dry mouth (salivary glands become blocked)
Clinical diagnosis is often adequate ☺
MUMPS:
- possible complications? 4
ORCHITIS in males → infertility: 50% of post-pubertal males (nb uncommon in pre-pubertal boys)
- Chills, sweats, headache, backache, swinging fever
- Severe local testicular pain + tenderness (U/L common)
- Swollen scrotum – testes may be impalpable
Hearing loss – U/L and transient
Acute Pancreatitis (4%) or Myocarditis –
Meningitis (15%) – usually mild and self-limiting
MUMPS:
- management? (1 if in hospital, 2 if anywhere)
isolation (if in hospital)
- fluids + nutrition
- paracetamol
(can give antivirals if severe!)
RUBELLA
- prodrome? 1
- describe rash?
- associated symptoms? 2
- feature common in older pts? 1
Prodrome = Low grade fever
MACULAR RASH
– pink discrete on face → coalesce whole body (fades after 3-5d)
Forcheimer spots – red spots on palate of mouth
Lymphadenopathy – post-auricular, sub-occipital, cervical
Arthralgia – in older patients (common)
RUBELLA:
- how diagnose?
- gold-standard test? 1
- management? 3 (2 for pt, 1 Q re contacts)
Diagnosis is unreliable as Sx are fleeting and mimicked by other viruses
Serology ± PCR testing of saliva = gold standard, detect IgM +ve
- fluids + nutrition
- paracetamol
- ask about contact w pregnant women!
RUBELLA:
- main complication? 1
- other complication? 1
FOETAL DAMAGE – teratogenic during 1st 8-10 wks
- encephalopathy (6 d post rash)
If someone presenting with diarrhoea, what 3 questions should you always ask them (about risk factors) to narrow down cause?
- any foreign travel?
- any new foods?
- any recent Abx? (or other meds changes)
INFECTIVE GASTROENTERITIS:
- seasons most common in? 2
- risk factors? 4
winter + spring
- poor hand hygiene
- undercooked food
- travelling
- immunocmpromised
(also recent Abx for C diff)
INFECTIVE GASTROENTERITIS:
- most common cause in adults? 1
- most common cause in children? 1
- other viral cause?
- bacterial causes? 4
Norovirus (adults)
Rotavirus (child)
Adenovirus (10-15%)
BACTERIAL CAUSES (rare)
- campylobacter
- E.coli
- salmonella
- cholera
INFECTIVE GASTROENTERITIS:
- two main symptoms?
- duration of each of these?
- what other features to ask about? 3
WATERY DIARRHOEA (lasts 5-7 d, resolves in 2 wks) - ↑Frequency + Loose consistency
VOMITING
(lasts 1-2 d, resolves in 1 wk)
- Causes dehydration
stomach cramps
fever
blood or mucus in stools
Infective gastroentertis: what examining for on physical exam?
signs of DEHYDRATION
Sunken eyes, ↓skin turgor, ↓exhaustion, ↓Urine output (not weeing),↑HR (weak), ↓BP, ↑CRT
What is dysentry?
Dysentery is ANY infection of the intestines that causes diarrhoea containing BLOOD or MUCUS
can also get fever, vomiting and stomach cramps
nb norm bacterial cause!
INFECTIVE GASTROENETERITIS:
- causes of bloody diarrhoea? 3
- cause of ‘rice water stools’? 1
CAUSES OF BLOODY DIARRHOEA
- shigella
- campylobacter
- E.Coli 0157
‘rice water stools’ = CHOLERA
INFECTIVE GASTROENTERITIS:
- when to send a stool culture? 6
- when to admit a patient? 2
SEND STOOL CULTURE IF:
- blood OR mucus in stools
- been abroad
- immunocompromised
- septicaemia
- diarrhoea not improved in 7 days
- uncertain over Dx
admit pt if:
- patient is septic
- patient is severly dehydrated
INFECTIVE GASTROENTERITIS:
- mainstay of management? 1
- when to consider Abx?
- when can go back to work?
oral rehydration solution = mainstay
- and lots of fluids
(IV fluids if not taking things orally)
consider Abx if severe AND suspect bacterial infection (eg blood/mucus)
Possible complication of E Coli gastroenteritis? 1
what is this? (3 main features)
management? 4
HAEMOLYTIC URAEMIC SYNDROME (HUS)
- most common cause of AKI in children
E Coli 0157 produces toxins
- >
- abdo pain
- bloody diarrhoea
- fever
- lethargy
- seizures
1) anaemia
2) thrombocytopenia
3) renal insufficiency
MANAGEMENT
- mainly supportive
- NO antibiotics
- dialysis
- plasmaphoresis / IVIG
Possible complication of bacterial gastroenteritis? 1
Post-dysentric reactive arthritis
– due to salmonella, shigella or campylobacter (HLAB27 related)
→ Urethritis, Arthritis, Conjunctivitis
MALARIA
- causative organism?
- vector? 1 (be specific)
parasitic disease caused by species of the genus PLASMODIUM, travels in 1st vector (ANOPHELES mosquitos)
MALARIA:
- risk factors? 6
- protective factors? 2
- African countries
- lower socioeconomic groups
- pregnancy
- elderly
- travellers
- foreign aid workers
Protective factors:
- G6PD lack
- Sickle-cell trait
MALARIA:
- most severe type? 1 (incl incubation period + frequency of fevers)
- other types? 3
Plasmodium FALCIPARUM = most severe disease
- incubation 7-14 d
- travellers present within 8 wks
- DAILY Sx are common
- plasmodium vivax
- plasmodium ovale
- plasmodium malariae
nb in these less severe strains tend to get fever paroxysms every 3 or 4 days!
MALARIA:
- main feature? describe how this presents? (incl associated symptoms)
FEVER PAROXYSMS
= cyclical fevers (reflect synchronous release of flocks merozoites from mature schizonts)
Phase 1 (≤ 1hr) - Shivering / rigors
Phase 2 (2-6hr)
- Fever (HIGH temp > 41)
- flushed
- dry skin
- nausea + vomiting
- headache
- myalgia
Phase 3 (3hr) – Cold Sweats as temp falls (to norm or below)
then tend to sleep and be asymptomatic for 1-3 days until have another cycle!
nb Sx may occur from 6 d of infection → many months later
MALARIA:
- possible signs on examination? 2
Spleno/hepatomegaly ± abdominal tenderness
Jaundice
MALARIA:
- stain used on blood film to see? (what see if falciparum)
- what to do if can’t see on blood film but high clinical suspision?
Serial Thick + Thin Blood Films – stained w/ GIEMSA STAIN (gold standard)
SCHIZONTS = falciparum
If –ve, at least 2 further films should be obtained over 48 hrs to exclude malaria
nb also do other blood tests: FBC, U+Es, LFTs (can be deranged), glucose, VBG, clotting
Main DDx of malaria? what test to do to exclude this? 1
sepsis!!!!
look for source of infection AND do blood cultures
Management of MALARIA
- 1st line drug if non-falciparum?
- how to manage if drug-resistant or uncomplicated falciparum?
NON-falciparum
= oral CHLOROQUININE
if drug-resistant (common) or uncomplicated falciprum
= oral QUININE and some other drugs… (don’t bother learning names!)