Path 3 Flashcards
Risk factors for SSI
- age (>45)
- ASA 3 or more
- diabetes
- malnutrition
- low serum albumin
- DMARDs
- obesity (adipose tissue is poorly vascularised)
- smoking
Main pathogens causing SSI
FC levels of SSI deep superficial etc
Measures to decrease number of surgical site infections
PRE-OP
- pre-op showering
- nasal dΓ©colonisation (for some surgeries, e.g. cardiac)
- antibiotic prophylaxis (at induction of anaesthesia, need to achieve bactericidal levels at the time the incision is made; in prolonged OP or lots of blood loss,
- hair removal not with razor but electrical clippers because prevent micro abrasions
OP
- reduce number of poeple in theatre
- ventilation (+ve pressure, direction of air flow is from theatre to rest of the hospital; 20 air changes/h, all air coming in is filtered, keep theatre doors closed; orthodoxy surgeries in laminar flow theatres)
- sterilised instruments
- skin prep (chlorhexidine in 70% EtOH)
- asepsis and surgical technique
- normothermia
- O2 sats >95%
Incidence of SA
Incidence of SA
mortality and morbidity in SA
RFs for SA
- prosthesis
- immunosuppression
- underlying joint disease
- IVDU
Pathophysiology of SA
see screenshot
includes bacterial and host factors
Pathophysiology of SA
see screenshot
includes bacterial and host factors
Host factors for SA pathophysiology
- genetic variation in cytokine expression
- more
bacterial factors in SA pathophysiology
Commonest pathogens
- staph aureus
- streptococci
- gram -ve organisms
Presentation of SA
- ## 1 red, hot, swollen joint
Ix for SA
- blood cultures
- synovial aspiration
- bloods
USS to guide needle aspiration
MRI scan to look at damage and
Abx for SA
flucloxacillin
cephalosporin
may need to add vancomycin if MRSA
review after 2 weeks -> switch to oral for 4w if good response, if not good continue for 4 weeks IV
Vertebral osteomyelitis
- acute haematogenous
- add
Commonest organisms in vertebral osteomyelitis
- staphylococcus
- streptococci
commonest location of
lumbar spin
- cervical spine
PC in VOM
- back pain
- fever
- may have neurological sx
Ix in VOM
MRI?
add mroe
Mx of VOM
- 6w Abx
- may need longer course if untrained abscess, foreign material
- may need surgery if there are neurological issues/compression
commonest organisms causing prosthetic joint infection
- coagulase -ve staphylococci
- staph aureus
- g-ve less common
what dies the presence of alpha-defensin indicate?
infection (in the bone)
what dies the presence of alpha-defensin indicate?
infection (in the bone)
What haematological changes are normal in pregnancy?
- mild anaemia (physiological) - plasma volume rises 150%, red cell mass rises 120-130%)
- macrocytosis (normal - physiological, but does not exclude folate or b12 deficiency)
- neutrophlia
- thrombocytopenia (and increased platelet size)
iron deficiency in pregnancy - consequences
IUGR
prematurity
PP haemorrhage
Dose of folate pre conception and in first trimester
400 ug/day
What happens to platelets in pregnancy?
count decreases (15% women will have below 150)
size increases
there may also be some clumping
Causes of thrombocytopenia in pregnancy
- physiological
- pre-ecclampsia
- ITP
- microangiopathic syndromes
- other (e.g. DIC, leukemia, β¦)
thrombocytopenia number
<140 x 10^8 /L
double check this
IgG autoantibodies from ITP can cross the placenta so the baby may be affected
significantly low platelets (<20) in 5% of the babies
How do you manage ITP in pregnancy?
- steroids
?check IViG?
HUS and I think there is a lot more to say here and I think there is so much more to say here
What medication can be given to women to increase uterine contraction?
syntosin
(synthetic oxytocin)
What medication can be given to women to increase uterine contraction?
syntosin
(synthetic oxytocin)
When around pregnancy is the risk of VTE highest?
6 weeks following delivery
VTE risk assessment done before, throughout and after pregnancy
good hydration is important during pregnancy
Causes of DIC
- infections
- obstetric causes
fill out this list
Scan to check for metabolically active metastases?
FDG-PET
Scan to check for bone metastases?
Tc bisphosphoante scan
What happens to the apex beat in LV hypertrophy?
the apex beat is normal
LV hypertrophy does not cause apex displacement.
tall R waves and deep s-waves because the muscle is huge.
you only see displacement if there is also heart failure
do not confuse a dilated heart with a hypertrophic heart
commonest cause of LV hypertrophy
untreated HTN
What type of bacteria are neisseria gonorrhoeae?
gram -ve diplococci
What type of bacteria are neisseria gonorrhoeae?
gram -ve diplococci
What can cause gram -ve meningitis in children? (rods)
g-ve diplococci on LP in meningitis Sx
Neisseria meningitidis
g-ve rods causing meningitis Sx in a 6yo child - organism?
Haemophilus influenzae
less common in vaccinated kids but in the unvaxxed
E coli is also a gram -ve rod and causes meningitis in neonates and premies
gram +ve diplococci causing sepsis that we are worries about
strep pneumoniae
19 yo with PUO cultures -ve for 2 months but cold agglutinins are positive - organism?
mycoplasma
- gives you cold agglutinins
?also takes long to culture?
gram+ve cocci in clusters from pus of a boil
staph aureus
the clusters make it likely to be staph aureus
it is the aggressive organism that attacks joints, foreign material etc.
staph epidermidis
found on skin
can also cross the skin and cause sx
much less aggressive than staph aureus
Strep viridans
gram +ve cocci
can cause strep viridans endocarditis
PUO
slowly can damage the endocardium
Which organism are you more likely to get endocarditis/sepsis from?
strep pyogenes and strep viridans
strep pyogenes kills you by sepsis before it can settle on valves
strep viridans can cause PUO and endocarditis because it is less virulent and can settle on the valve
more virulent bugs may be less likely to cause endocarditis thereby
Signs of subacute endocarditis
- splenomegaly
- haematuria
- splinter haemorrhages
- heart murmurs
Where does strep viridans come from
teeth
What is the commonest cause of meningitis
viral
e.g. coxsackie B virus
what is aseptic meningitis?
viral meningitis
how do you manage viral meningitis?
?supportive management
LP result in SAH
- red cells
- yellow colour
Stain in TB
Ziehl nielsen
LP result in TB meningitis
normal LP but culturign shows TB
Commonest cause of secondary immunodeficiency worldwide
malnutrition
especially protein loss malnutrition
measles induced immunodeficiency
- lasts months to years
- implicated in increased morbidity and mortality
How does TB lead to immunodeficiency?
???
TB IRIS
TB immune reconstitution syndrome
Drugs as a cause of immunodefiocicnet
- small molecules (steroids, cytotoxic agents, calcineurin inhibitors, anti epileptic drugs, DMARDs)
- Jak inhibitors
- biologics and cellular therapies
- haematological cancers (B-cell and plasma cell cancers; chemotherapy; Goodsβ syndrome)
Goodsβ syndrome
- thymoma associated with Ab deficiency
- combined T- and B-cell problem
- absent B cells, no antibodies
- increased risk of PJP, CMV, fungal and AI disease
Ix for ?secondary ID
FISH
FBC
Immunglobulins
S??
HIV test
Ix for ?secondary ID
FISH
FBC
Immunglobulins
S??
HIV test
How many people are living with HIV?
37 million
How many of the people living with HIV are taking ART
21 million of 47 million
How many poeple in the UK are living with HIV?
101 200
approx 100 000
virus family of HIV
lentivirus family
what kind of virus is HIV?
double stranded RNA virus
structural, replicative and accessory proteins
retrovirus