L20 - Chronic diseases and infections Flashcards
How do chronic diseases predispose patients to particular infections?
Can alter the structure and fuction of tissue and organs/alter the microbial presence due to treatment
What mode of inheritance does Cystic Fibrosis show?
Autosomal recessive
Explain the pathophysiology of CF
Defect in the CFTR chloride channel -> reduced secretion of osmotically active chloride -> water doesn’t follow -> thick mucus -> builds up in lungs
Name some specific complications related to CF
Lung infection due to microbes in the mucus/ pancreatitis/bowel obstruction/liver cirrhosis/sinus infections/infertility
Name three bacteria that CF patients are particularly at risk of causing lung infections
MAIN ONE - Pseudomonas aeruginosa/S.aureus/H.influenzae/fungi like Candida albicans and Aspergillus
All causing lung infections
Pseudomonas aeruginosa is an aerobic bacteria, describe it’s structure
gram negative bacilli/ Causes opportunistic infections/ biofilm agent
What sample would you take in someone with CF to identify P aeruginosa infections?
sputum/urine depending on type of indections caused
Name two preventative meaasure CF patients can take to prevent respiratory infections
Chest physio/Nebulisers/bronchodilators/god nutirtion/good hand hygiene
What is the treatment for pseudomonas infection and why?
These rapidly develop resistance so require a combination of antibiotics - normally Tazocin and gentamycin/cirpofloxacin/ceftazidime
Why are diabetic patients at a higher risk of infection? Give two reasons
Hyperglycaemia impairs neutrophil and lymphocyte function/vascular disease caused by it leads to poor tissue perfusion and increased infection risk/neuropathy causes increased risk of cuts going unnoticed
Name two infections that diabetic patients are particularly at risk of
cellulitis/UTI/s/malignant otis externa/respiratory infections
What are the major causative organisms for cellulitis?
S. aureus/ Group A strep (S. pyogenes)/ polymicrobial often
A man walks into A and E with a severe foot ulcer, he is diabetic. What do you do?
Clean the wound
Swab the site
blood cultures
check HbA1c
FBC, CRP
U and E’s (kidney function important in diabetes)
Foot X-ray to see if infection has reached bone
Why are UTI’s common in diabetic patients?
Neuropathy leads to defects in bladder emptying -> stasis -> increased risk of infections
What are the causative organisms for UTI’s?
E. coli/P. aeruginosa
What investigations would you carry out in a patient presenting with a UTI?
Nitrites and leucocytes
Glycosuria
potentially a sepsis screen
FBC/CRP/ U and E’s
Malignant otis externa is a complication of diabetes mellitus. It is an infection which has spread to the soft tissue, bone and cartilage. Patients typically present with severe ear pain and otorrhea (ear discharge). What is the causative organism?
P. aeruginosa
Explain COPD
Chronic inflammatory response as a result to long term irritation by smoking -> airway remodelling and increased mucus production
Pneumonia is a common complication associated with COPD. What are the main causative organisms?
H. influenzae/P. aeruginosa
