infection and shock Flashcards
(59 cards)
What is pericarditis?
Typically acute (can be chronic); inflammation of pericardium +/- effusion -pericardium has two layers and innervated by phrenic hence inflammation results in pain
Epidemiology of pericarditis?
- males - 20-50yrs
Causes of pericarditis
1) Usually idiopathic 2) Or caused by a virus: - most common cause = coxsackievirus - mumps - EBV - VZV - HIV Less common causes: - bacterial - TB - systemic autoimmune disorders - malignancy - trauma
Pathophysiology of pericarditis
- inflamed pericardial layers rub against each other = more inflammation -cause exudate and adhesions within pericardial sac 1) may stay dry (no extra fluid needed to compensate for friction) 2) develop pericardial effusion (extra fluid) - if it become
Symptoms of pericarditis
Sudden onset sharp, pleuritic chest pain which can spread to left shoulder tip (phrenic) - Relieved by sitting up or leaning forward - Worse laying flat *may have signs of rhs failure due to constructive pericarditis -> SOB, peripheral oedema and tachycardia
Sign of pericarditis
Pericardial friction rub on auscultation - heard at left sternal edge as patient leans forward - squeaky leather “to and fro” sound
Differential diagnosis of pericarditis
Most key to rule out MI - central crushing chest pain not related to lying down - no pericardial rub
What is constructive pericarditis
- granulation tissue formation in pericardium means impaired diastolic filling as it becomes thickened and hardened - late complication of pericarditis - sign of poor prognosis—> congestive heart failure - commonly associated with TB
Primary investigations to diagnose pericarditis
ECG: widespread saddle shaped ST-elevation (sensitive) and PR depression (specific) Eg. CXR: may show “water bottle” heart = pericardial effusion - pneumonia commonly seen in bacterial pericarditis Transthoracic ecg: to exclude pericardial effusion or tamponade ESR and CRP: might increase due to inflammation Troponin will be daisies if there’s an element of concomitant myocarditis
Treatment for idiopathic or viral pericarditis
1st line: NSAIDs + Colchine 2nd line: NSAIDs + Colchine + low-dose prednisolone
Treatment for bacterial pericarditis
IV antibiotics and pericardiocentesis with washout, culture and sensitivities
Compilcations of pericarditis
1) Pericardial effusion—> cardiac tamponade 2) Myocarditis 3) Constrictive pericarditis
What is infective endocarditis
Infection of endocardium: - an abnormal endocardium - bacterial source —> vegetation
Two most common causes of infective endocarditis
1) S.aureus- most common overall + associated with IV drug use and prosthetic heart valves => increased virulence, Sx onset in days-weeks = ACUTE 2) S.viridans- second most common + usually affects a native valve and associated with poor dental hygiene => decreased virulence, Sx onset in weeks-months = SUBACUTE
Catergorisations of endocarditis
1) Acute 2) Subacute 3) Non- bacterial thrombotic ‘marantic’ - non-infective cause of endocarditis secondary to thrombus formation on the valvular surface - associated with malignancy or SLE (Libman-Sacks endocarditis)
Other less common causes of infective endocarditis
S. Bovis (associated with colon cancer) S. Epidermis (associated with in dwelling lines and prosthetic valves) HACEK organsisms (usually culture -ve) - Haemophilus - Aggregatibacter - Cardiobacterium - Eikenella - Kingella
Risk factors for infective endocarditis
Male 2.5x Elderly with prosthetic valve Young IV drug user Young with congenital heart defect Rheumatic heart disease
Which valves are more commonly affected by Infective endocarditis
Mitral valve most commonly affected overall Tricuspid valve is most associated with IV drug use (Mitral valve)
Pathophysiology of infective endocarditis
- any cause of abnormal endocardium —> turbulent blood flow and thrombus formation (platelets) - thrombus can get infected due to bacterial source - bacterial colonisation of the thrombus —> formation of vegetations —> valvular damage -ty
Symptoms of infection endocarditis
Rather vague -Fever or chills -headache -SOB -night sweats, fatigue, weight loss -joint pain (might be due to septic emboli)
Signs of infective endocarditis
1) Osler nodes (painful nodules on fingers\toes) 2) Janeway lesions (painless placques on palms and soles) 3) splinter haemmorrhages (red plum lines under nails) 4) Roth’s spots: white centred retinal haemorrhages heart murmer +- signs of heart failure
Primary investigations for infective endocarditis
-ECG (prolonged PR interval=aortic root abscess) -Blood cultures - 3 sets in 24 hours BEFORE ANTIBIOTICS -Inflammatory markers (CRP) - eg raised ESR\CRP + neutrophillia -FBC -ECHO: TOE more invasive than TTE but much more sensitive and specific = gold st
What is the modified Duke Criteria
Requires 2 major criteria, or 1 major and 3 minor, or 5 minor criteria for diagnosis of infective endocarditis
Major Duke Criteria for infactive endocarditis
- 2 positive blood cultures - ECHO TOE shows endocardia’s involvement Eg. Vegetations , abscess or regurgitation
