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