Infectious disease emergencies: Therapeutic issues Flashcards
Define sepsis
Clinical evidence of infection
2 or more (qSOFA):
Altered mentation (Glasgow Coma Scale <15)
Respiratory rate ≥22/min
Systolic BP ≤100 mm Hg
Septic Shock
is sepsis with hypotension (systolic BP <90 or >40 fall in systolic BP) persisting despite fluid challenge
Compromisation of intestinal barrier
Peritonitis: release of bacteria into the system
Liver Injury
Impaired detoxification
Impaired coagulation: bleeding and DIC
Altered metabolic response: Glycaemias
Bilirubinaemia: Cholestasis, Jaundice
Acute Respiratory Distress syndrome (ARDS)
Leaky capillaries- compromised oxygen delivery
access route fir secondary Respiratory Infection
Thymic involution
Apoptosis
Impaired T lymphopoiesis
Lymphagitis
abscess
compromised local immune cell function
Encepholopathy
Hypoxic ischaemic brain damage: Coagulopathy
Blood brain barrier dysfunction
Delirium decreased neurotransmitter release
Heart failure
Tachycardia >90, low O2 in blood, hypotension
Defective contractility low Cardiac Output
Splenic Pathology
Splenomegaly
Atrophy of lymphoid follicles
Renal failure
Ischaemia
Bone marrow suppression
Myelosuppression/lymphopaenia
apoptosis of WBCs
Describe the pathophysiology of sepsis.
Excessive inflammation that leads to tissue damage whilst simultaneously having antiinflammatory response that impairs and kills lymphocytes, causing host to be susceptible to secondary infections
with this there is an increase in coagulation and decrease in anticoagulation leading to thrombosis and and vasodilations respectively leading to tissue hypoperfusion
additionally capillaries lose barrier functions due to cell shrinkage which leads to capillary leaks and interstitial oedema
together there is less oxygenation of tissue
How do manage sepsis?
Start approp resus and general support urgently
Inotropic agents
empirc antimicrobials ASAP decreases mortality
Inotropic agents
adrenaline/epinephrine infusions
Explain why a loading dose is given in a septic person.
Most antimicrobials are water soluble, they follow where ever the water goes, giving a loading dose accommodates for the loss of antimicrobial into interstium and allows for early achievement of steady state.
Explain why IV administration of antimicrobials are preferred over oral or IM ones in the management of a septic patient.
Absorption of drug from GIT, s/c or IM is poor due to altered haemodynamics.
Conventional bacteria/typical bacteria causing Pneumonia
Streptococcus pneumonia
H. Influenza
K. Pneumoniae
Moraxella catarrhalis
S. Aureus
Atypical bacteria causing pnuemonia
Mycoplasma pnuemoniae
chlamydophila pnuemoniae
legionella spp
how to manage sever CAP
Broad spectrum -lactam (to cover Gram+ & Gram- conventional bacteria)
PLUS
Macrolide (to cover “atypical” bacteria)
Oxygen if saturation <94%
Name B-lactams that would be administered to in severe CAP.
Penicillin G
ampicillin
Cloxacillin
Name macrolides that are used in severe CAP
Azithromycin
Treatment for sever malaria.
If uncertain about criteria of severe malaria or you have a patient you feel concerned about not meeting criteria: treat as severe
Drug of choice artesunate followed by artermether-lumefantrine
cautious with fluids-do not over hydrate-pulmonary oedema
Features of severe malaria
lower levels of consciousness
seizures
Prostration
shock
acidosis
severe anaemia
visible jaundice
renal impairment
parasitaemia
hypoglycaemia
respiratory distres
what is the strongest predictor of the outcome bacterial meningitis when treatment has started?
Level of consciousness
can decrease rapidly
Treatment for bacterial meningitis.
ceftriaxone
Causes of Bacterial meningitis in ,<1 month
Streptococcus agalactae
Aerobic G- bacilli
Listeria monocytogenes
Causes of bacterial meningitis in 1-24 months
Neisseria meningitidis
Streptococcus pneumoniae
H Influenza
Causes of bacterial meningitis in 2-50
streptococcus pnuemoniae
Nesseria meningitidis
Causes of Bacterial Meningitis in >50
Streptococcus pnuemoniae
Aerobic G- Bacilli
L. Monocytogenes
Which bacteria does not respond to ceftriaxone?
Listeria monocytogenes
Signs and symptoms of Bacterial Meningitis
History
* Headache
* Fever
* Photophobia
* Nausea/vomiting
Examination
* Neck stiffness
* Pyrexia
* Reduced level of consciousness
* Focal signs
