Complex Infection Flashcards
Pathophysiology of Sepsis
- Pro-inflammatory response occurs due to the bacteria
- Leads to vasodilation and disturbances in micro-circulation because of an increase permeability in the endothelium so lose of fluid in the blood occurs
- Which causes mismatch in O2 supply and demand, mitochondrial dysfunction and apoptosis
- This leads to tissue hypoxia
- Then organ dysfunction such as Kidney (AKI), Brain (altered mental status), Skin (cold and mottled), Heart (tachycardia), and Respiratory (increased breathing rate)
- Lastly leads to disseminated intravascular coagulation so the patient needs to be anti-coagulated because blood clots can be formed.
Symptoms of Sepsis
Fast breathing Skin rash/clammy/mottled skin Fast heartbeat Weakness or aching muscles Not passing much urine Altered mental status
Diagnosis of sepsis
- Lactate - elevated due to anaerobic process because of a lack of oxygen
- Observations
- Full blood test and U&Es
- Cultures
Assessment and screening tools of sepsis
- SIRS (systemic inflammatory response syndrome)
- SOFA; qSOFA (Sequential organ failure assessment)
- NEWS2
- NICE - risk stratification
SEPSIS 6 bundle
- Administer high flow oxygen if required
- Blood cultures and consider infective source
- IV antibiotic (start broad then go narrow once pathogen identified)
- Fluid resuscitation (IV)
- Check repeat lactate (after 2 hrs)
- Urine output (check hourly for 2 hours)
Completed the bundle within 1 hrs of risk identified.
Treatment goals of SEPSIS
- Resuscitate patient and restore haemodynamic stability
- Identify source of infection
- Start abx broad with bacterial infection
- switch to targeted abx once pathogen identified
- Maintain organ system function
Monitoring for SEPSIS
- Lactate
- O2 Sats
- Fluid balance
- Temp
- Heart rate
- Blood pressure
- Respiratory rate
Prevention of SEPSIS
- Vaccination - follow recommended immunisation schedules for children and adults
- Good general hygiene - washing hands, cleaning scraped and wounds
- Appropriate PPE
- Antibiotic stewardship - Adherence to antibiotic and finishing course
What is Meningitis
Inflammation of the membrane covering the brain and spinal cord - the subrarchnoid space is the common area of inflammation
Most common bacterial meningitis
Neisseria meningitidis B, Gram-negative
Transmission of meningitis
Human to human
Through droplets such as kissing and living in close contact
Pathophysiology of Meningitis
- Bacteria (enters through the blood stream) and invades subarachnoid space
- Subarachnoid inflammation
- Blood brain barrier disruption
- Inflammation of the brain parandymea
- Oedema (causes raised intracranial pressure) and Ischaemia (leads to necrosis of the brain)
Risk factors for Meningitis
- Infants and young children
- Community setting -close contact
- People who are immunocompromised
- Exposure to active or passive tobacco and smoke
- Elderly
- pregnancy and working with animals increases the risk of Listeria meningitis
Signs and symptoms of Meningitis
•Fever •Headache •Photophobia •Neck stiffness •Petechical rash In young children •poor feeding •nausea and vomiting •cold extremities •muscle and joint aches •stiffness in neck and hamstring
Diagnosis of Meningitis
•microbiological testing of CSF sample is gold standard because no pathogen should be in there
Desirable characteristics of antibiotic agent for meningitis
- IV therapy
- broad spectrum
- crosses BBB - lipophilic agent
- bactericidal
3rd generation cephalosporin are first line treatment e.g ceftraxine
If allergic to cephalosporin then use Chloramphenicol
Although ceftraxine is hydrophilic it can still penetrate the BBB because inflammation makes it more permeable. Still require a high dose of it
Supportive therapy for Meningitis
- respiratory support
- IV fluids
- Corticosteriods - dexamethasone can help reduce neurological complications
- anticonvulsant therapy if required
- management of septicaemia and shock (correction of metabolic disturbances e.g metabolic acidosis, vasoactive therapies, renal replacement therapies if required)
Long-term complications of meningitis
- Fatigue
- Emotional changes e.g clinginess, mood swing, tantrums
- Hearing loss - need hearing tested after full recovery
- Visual disturbances
- Neurological and developmental problems
Prophylaxis for meningitis
Chemoprophylaxis indicated for:
Patient, close contact of patient
•Ciprfloaxcin
•Rifampicin
•Ceftriaxone - given by injection so not suitable choice
Are the choices for prophylaxis
What is Endocarditis
- Infection in the lining of the heart and the cusp of the cardiac valves.
- Caused by the micro-organisms adhering to and multiplying on the innermost chamber of the heart and it’s valves
Risk factors for Endocarditis
- Congenital and degenerative valve disease
- Rheumatic heart disease (not seen much in rich countries)
- IV drug abusers
- Valvular or cardio surgery
- Central venous lines
- Ventricular septal defects
Pathophysiology of Endocarditis
- Formation of thrombi on endocardium
- Endothelial lining is damaged by previous infection or injury
- that exposes the underlying collagen and tissue factors
- Causes platelet and fibrins to adhere to the injured site - forming a non-bacteria thrombotic endocarditis (NBTE)
- Bacteria adheres to NBTE and causes vegetation and secretes adhesins
- Ahesins allows the bacteria to stick to each other and create a biofilm so they can be a large clump.
- Biofilm occurs in area of low pressure
Most common bacteria cause of Endocarditis
- Vividans streptococci -found in the mouth and can occur when brushing teeth - Gram-positive (90% of the time this bacteria)
- S.Aureus - found on skin and associated with IV drug users
- S.epidermis - common with prosthetic valve.
Which valves are commonly affected in Endocarditis
Mitral and Aortic valve
Clinical presentation (symptoms) of Endocarditis
- Fever
- Heart murmur
- Fatigue
- Malaise
Diagnosis of Endocarditis
- blood cultures - at least 3 before imitation of therapy but never withhold treatment
- echocardiography
- chest x-ray
- ECG
- FBC
Treatment of Endocarditis
Empirical treatment is patient has native or prosthetic valve.
•of prosthetic valve then RIFAMPICIN is added to the regimen
•RIFAMPICIN is given with Vancomycin and Gentamicin because it is prone to resistance
Complications of Endocarditis
- Heart failure
- uncontrolled infection
- embolic events e.g stroke
Role of surgery in Endocarditis
Early surgery • improves mortality in high risk patients •heart failure • uncontrolled infection • high embolic risk
Elective surgery
•patient has to be stable and no complications
Endocarditis prophylaxis
Used if patient:
• acquired valvular heart disease with stenosis
• previous infection of endocarditis
• dental procedure that might involve perforation of the oral mucosa
Counselling points for Endocarditis
- benefit and risk of antibiotic prophylaxis
- importance of good oral hygiene
- symptoms and when to seek for expert advice
- risk of undergoing invasive procedures
Using Gentamicin
• use ideal body weight (IBW) because it is hydrophilic
•given once daily to reduce nephrotoxic effects
•it is concentration dependent and has a long post antibiotic effect
•monitor renal function before and during treatment
-required therapeutic drug monitoring
Side-effects: nephrotoxicity, Ototoxicity, GI effects, infusion reactions
Vancomycin
Class? Measurement? Monitoring? Side-effects?
•Glycopeptide protein
•use actual body weight
•monitor renal function and adjust dose accordingly
- requires therapeutic drug monitoring
Side-effects: nephrotoxicity, ototoxicity, hypersensitivity, red man syndrome and anaphylaxis
Rifampicin - use, and side effect
- has good tissue penetration
- potent enzyme inducer - so interacts with warfarin and the PILL
- side-effects: GI disturbance, headache, hepatotoxicity, temporary reddish-orange discolouration of bodily fluids
What is a lower UTI called
Cystitis
What is an upper UTI called?
Pyelonephritis - affects kidney area
Causes of UTI
- proximity to anus
- E. coli
- pregnancy
- catheters
- kidney stones
- enlarged prostate
- constipation (kids)
- Familia link
- urinary tract abnormalities •weekend immune system
Symptoms of LUTI
- incomplete emptying feeling
- new Nocturia
- Dysuria
- Haematuria
- Cloudy urine
- increased frequency and urgency
Symptoms of UUTI
- systematically unwell
- flank or loin tenderness
- suprapubic pain
- Fever
- in babies: poor feeding and failure to thrive
Diagnostic testing of UTI
- Mid-stream urine culture - detects pathogen in the urine
- Dipstick test - can detect nitrites and WBC which indicates infection
Why is Nitrites present in UTI
E.coli breaks down Nitrates to Nitrites for anaerobic growth
Differential diagnosis of UTI
- thrush/bacterial vaginosis
- kidney stones
- STI
- pelvic inflammatory disease
- benign prostate hyperplasia
- bladder cancer
Self care for UTI
- water
- alkanising agents e.g potassium and sodium citrate, sodium bicarbonate -avoid in elderly
- pain relief e.g paracetamol and ibuprofen
Avoid Ibuprofen with SSRI, asthma, elderly, CVD and anticoagulants
Antibiotic choice for LUTI in women
1st line: Nitrifurantoin MR 100mg BD 3 days
2nd line: Trimethoprim 200mg BD for 3 days
Safety net for LUTI
Symptoms worsening or not improving within 48hrs Shivering and chills Confused or drowsy Smelly urine Kidney pain in the back Nausea and vomiting
Prevention of UTI
- wipe from front to back after using the toilet
- don’t wait to pass using me, go as soon as needed
- urinate after sex
- drink enough fluid to urinate throughout the day
- good genital hygiene
- avoid occlusive underwear
Antibiotic for LUTI in pregnant women, men and with indwelling catheters
1st line: Nitrofurantoin 100mg MR BD 7 days
Trimethoprim 200mg BD for 7 days ( AVOID IN PREGNANCY AS TERATOGENIC)
2nd line: Amoxicillin 500mg TDS for 7 days - has widespread resistance
Cefalaxin 500mg BD for 7 days - has c.diff side-effect
Ciprofloxain could be used if inflammation in prostate because of it’s good tissue penetration
Treatment of UUTI
Association with sepsis so treat patient for longer (10-14 days)
1st line: oral co-amoxiclav or ciprofloxacin (both associated with c.diff)
What is pneumonia
Inflammation of the lungs characterised by consolidation
Which common bacteria cause pneumonia
Bacteria: streptococcus pneumonia and S aureus
What does the CURB-65 score stand for?
- Confusion of new onset
- Urea - blood urea >7mmol/L
- Respiratory rate of 30 bpm
- Blood pressure <90 mmHg systolic or 60mmHg diastolic
Age =/> 65 years old
Community-acquired pneumonia treatment
First line- Amoxicillin + Clarithromycin/Erythromycin
Second line - doxycycline
Prevention of pneumonia
- Immunisation schedule
* Lifestyle advice - smoking cessation, healthy diet, good hygiene and promote exercise
Complication of pneumonia
- pleural effusion
- lung abscess
- sepsis
- CVE
What is community acquired pneumonia
Pneumonia 48 hrs before hospitalisation
What is hospital acquired pneumonia
Pneumonia 48hrs after hospitalisation
Symptoms of pneumonia
- cough
- fever
- lung infiltration
- crackles
- sputum production
Can you use antibiotics with the pill
Yes except for RIFAMPICIN because it is a potent enzyme inducer
What’s the MOA for ondasetron
•Serotonin receptor antagonist
Causes prolonged QT interval and increase serotonin syndrome with SSRI
MOA of Cyclizine
•antihistamine
Crosses BBB and causes sedation
MOA of metoclopramide
•dopamine receptor antagonist
Do not use in patient with Parkinson’s disease
MOA of dexamethasone (as anti emetic)
•corticosteroid
Does not cross the BBB
MOA of haloperidol
•blocks post synaptic dopamine receptions in the brain
Used for opioid-induced nausea and vomiting
MOA of domperidone
•work on chemoreceptors trigger zone and less likely to cause sedation and movement disorder
Does not cross BBB and interacts with CYP3A4 inhibitors
Has cardiac side-effects
INR target for re-current DVT
3.5
INR target for first DVT
2.0-3.0 (2.5)
When would you stop warfarin before an operation
Ideally 5 days before and use bridging therapy before the surgery like LMWH (e.g tinzaparin).
would try and stop LMWH 24 hrs before the surgery ideally
How do you re-start warfarin post operation
Use bridging therapy like LMWH e.g tinzaparin
For 48 hrs because it taken warfarin 48 hrs to reach therapeutic effect
What type of antibiotic inhibits bacterial cell wall synthesis
- Penicillins
- Cephalosporins
- Vancomycin (glycopeptide)
What class of drugs inhibit protein synthesis
- chloramphenicol
- Macrolide (Erythromycin)
- Tetracyclines (Doxycycline)
- Streptomycin
What class of drug inhibit nucleic acid transcription and replication
- Quinolones (Ciprofloaxin)
* Rifampicin
What class of drug inhibits the synthesis of essential metabolites
- Trimethoprim
* Sulphanilamide (sulfamethoxazole)
What’s the difference between gram +ve and gram -ve
Gram positive bacteria has ONE cell wall
Gram negative bacteria has a DOUBLE cell wall and periplasmic space
What antibiotic is used for meningitis dependent on age
3 months and younger - ceftriame + amoxicillin or ampicillin (for listeria meningitis)
Older than 3 months - ceftriaxone