Diseases Flashcards
What are the different types of shock?
Hypovolaemic (haemorrhagic and non-haemorrhagic)
Cardiogenic
Obstructive
Distributive (neurogenic and vasoactive)
Describe what happens in hypovolaemic shock.
Loss of blood volume
Resulting in decreased blood volume, venous return, end diastolic volume, stroke volume, CO and decreased blood pressure.
Causing inadequite tissue perfusion.
What is shock?
A systemic decrease in blood flow causing whole body circulatory failure leading to cellular failure.
What happens if there isn’t enough oxygen being delivered to cells?
Anaerobic metabolism will occur, leading to a decrease in ATP production and an increase in lactic acid. This is toxic to cells, so will result in multiple organ failure and death.
What is adequate tissue perfusion dependent on?
Adequate bp
Adequate CO
Therefore adequate SVR, SV and HR are required
What determines SV?
Preload (which is determined by venous return)
Myocardial contractility
Afterload
How would someone with haemorrhagic shock present?
Decreased MAP
Cool peripheries
Tachycardic
Small volume pulse
Describe what happens in cardiogenic shock.
There is decreased cardiac contractility.
Causing decreased stroke volume.
Which decreases CO and BP.
Leading to inadequate tissue perfusion.
In cardiogenic shock there is no decrease in volume. True or false?
True
Describe what happens in obstructive shock caused by tension pneumothorax.
Intrathoracic pressure increases causing decreased venous return (remember venous blood wants to flow high to low pressure), causing decreased EDV,
Causing decreased stroke volume.
Causing decreased CO and bp
Causing inadequate tissue perfusion.
Describe what happens in neurogenic shock.
Loss of sympathetic tone to blood vessels and heart.
Causing massive venous and arterial vasodilatation.
Causing decreased venous return, SVR, HR.
Causing decreased CO and BP
Resulting in inadequate tissue perfusion
What characterises neurogenic shock?
A decreased heart rate
Describe what happens in vasoactive shock.
Release of vasoactive mediators.
Causing a massive venous and arterial vasodilatation and increasing capillary permeability.
Causing decreased venous return and SVR/
Causing decreased CO and BP
Resulting in inadequate tissue perfusion.
What are the general symptoms of valvular heart disease?
Chest pain
Breathlessness
Collapse/dizzy spells
What is the New York Heart Association Functional classification used for?
To assess the severity and degree of heart failure by assessing breathlessness
What are the general signs of right-sided heart failure?
Raised JVP
Pitting oedema in the ankles and sacrum
Hepatic congestion
What are the general signs of valvular disease?
Apex beat:
- tapping (mitral stenosis)
- displaced (in left ventricular dilatation)
- heaving and displaced (left ventricular hypertrophy)
Parasternal heave
What could a parasternal heave be due to?
Right ventricular overload.
Cor pulmonale
Pulmonary hypertension
Congenital heart disease
What is a murmur?
Audible turbulent blood flow giving a whoosh sound.
What is a thrill?
A palpable murmur
What does S1 indicate?
The start of systole due to the tricuspid and mitral valves closing
What does S2 indicate?
The end of systole and the beginning of diastole due to the closing of the aortic and pulmonary valves
Which type of murmur coinside with the carotid pulse?
Systolic
Define myocarditis, endocarditis and pericarditis.
Myocarditis - inflammation of the myocytes
Endocarditis - inflammation of the endothelium of the valves
Pericarditis - inflammation of the pericardium
what are the symptoms of myocarditis?
Fever
Chest pain
SOB
Palpitations
what are the signs of myocarditis?
arrhythmias
cardiac failure
what is myocarditis most commonly caused by?
enterovirus
how do you diagnose myocarditis normally?
viral PCR
what is a bacteraemia?
Bacteria in the bloodstream
what can bacteraemia cause?
septic shock and death
what are the signs of a generator pocket infection?
localised cellulitis pain swelling discharge wound breakdown
what are the non-specific signs and symptoms of infective endocarditis?
Fever chills night sweats malaise anorexia
what investigations should be done if endocarditis is suspected?
Blood culture
then echo
but if blood culture -ve then use serology
Describe when and how many blood cultures should be taken.
taken prior to starting antibiotics
three sets optimally filled should be taken from peripheral sites at different times (only 2 if severe sepsis)
If it is early prosthetic valve endocarditis, what bug is usually responsible?
Staphylococcus epidermidis or staph aureus
Gram +ve is ___
and gram -ve is ___
\+ve = purple -ve = pink
What is the treatment for prosthetic valve endocarditis?
vancomycin and gentamicin (for added effect)
Describe the differences in endocarditis for PWID? (3)
affects the RHS
affects the tricuspid valve
normally staph aureus plus septic emboli
How can endocarditis be prevented?
pre-surgery prophylaxis antibiotics
what is the mortality of endocarditis?
up to 25%
which valve and side of the heart is usually affected in endocarditis?
mitral and aortic valves
LHS
list the 4 most common causes of endocarditis.
Staphylococcus aureus
Viridans group streptococci
Enterococcus sp
Staphylococcus epidermidis
What is staph epidermidis normally caused due to?
Plastic or metal or skin contaminant
How do you detect a-typical causes of endocarditis?
Serology - antibody detection blood test
Give and example of an a-typical organism causing endocarditis
coxiella burnetii
bartonella
legionella
What is the treatment for fungi caused endocarditis?
immediate surgery as antibiotics wont work
what are predisposing factors to endocarditis? (4)
Heart valve abnormality (calcification/sclerosis in elderly, CHD, post rheumatic fever)
prosthetic heart valve
IV drug user
IV lines
You can get endocarditis from poor dental hygeine/dental treatment. True or false
True
What can happen if vegitation forms in a patient with endocarditis?
it can break off causing septic emboli to enter the lungs or brain for example. Or cause abscess or haemorrahge
what are the symptoms of acute endocarditis?
severe sepsis and cardiac failure
What are the sub-acute symptoms of endocarditis?
Fever malaise weight loss tiredness SOB
what are the signs of sub-acute endocarditis? (9)
Fever new or changing murmur finger clubbing splinter haemorrhages splenomegaly roth spots Janeway lesions Osler nodes Microscopic haematuria
How is endocarditis diagnosed?
Two positive blood cultures with organisms typical for infective endocarditis
then an echo.
BUT if serology -ve then serology
what is the empirical treatment of native valve endocarditis?
Amoxicillin and gentamicin IV
what is the empirical treatment of prosthetic valve endocarditis?
vancomycin and gentamicin IV
add rifampicin in day 3-5
often valve replacement too
what is the treatment for endocarditis in PWID?
Flucloxacillin IV
what is the specific treatment for staph aureus in endocarditis?
flucloxacillin IV
what is the specific treatemnt for viridans strep in endocarditis?
benzylpenicillin and gentamicin IV
what is the specific treatment for enterococcus sp in endocarditis?
Amoxicillin/vancomycin and gentamicin IV
what is the specific treatment for staph epidermidis in endocarditis?
Vancomycin and gentamicin IV and rifampicin
Cocci in chains is?
Streptococci (like a strip)
Cocci in clusters is?
staphylococci
If alpha haemolytic strep (green) think? in endocarditis
Viridans group strep
what is hypovolaemic shock due to? list examples (4)
loss of blood volume
eg: haemorrhage, vomiting, diarrhoea, excessive sweating
what is cardiogenic shock due to?
the heart not pumping effectively: sustained hypotension due to decreased cardiac contractility
what could cause obstructive shock?
(tension) pneumothorax
what is neurogenic shock due to?
loss of sympathetic tone to the blood vessels and heart
what causes vasoactive shock?
release of vasoactive mediators (causing vasodilation)
