Week 140 - Septic and Anaphylactic Shock Flashcards
What is the equation for oxygen delivery?
Oxygen Delivery = blood flow x [Hb] x oxygen saturation
What are the types of shock?
Hypovolaemic shock = Cardiogenic shock = failure of heart Obstructive shock (embolism, tension pntx, tamponade) Maldistributive shock = abnormal dilation of small arteries
What is the equation for blood pressure?
BP = COxTPR
What happens in septic shock?
Vessels leaky -> hypovolaemia
Cytokine storm -> cardiogenic shock
DIC
Mitochondrial failure (can cause cell death even when O2 plentiful)
What is anaphylactic shock?
Extreme type 1 hypersensitivity reaction to a previously met antigen
Smooth muscle in bronchi usually contracts
Oedema and bronchospasm causes wheeze
What symptoms characterise shock?
Alterations to conscious level ↑RR ↑HR Hypotension Poor peripheral perfusion ↓Urine Output
What nerve innervates all muscles of larynx?
Vagus Nerve
What nerve innervates all pharynx muscles (except stylopharyngeus)?
Vagus Nerve
What nerve innervates stylopharyngeus muscle?
Glossopharyngeal Nerve (IX)
What muscle causes Abduction of the vocal cords?
Posterior cricoarytenoid
What is Reinke’s Oedema?
Oedematous and distended vocal cords
What can trauma to vocal folds given rise to?
Vocal fold nodules (bilateral)
Vocal fold polyps (singular)
What is the function of the palatopharyngeal sphincter?
When superior constrictor closes during swallowing, the sphincter seals the pharyngeal isthmus between the nasopharynx
What is the sensory distribution of the pharynx?
Nasopharynx = pharyngeal branch of maxillary nerve (V2) Oropharynx = CNIX Laryngopharynx = CNX
What is Waldeyer’s tonsillar ring?
Ring shaped arrangement of lymphoid tissue in the pharynx
What is Quinsy?
Peritonsillar abscess (complication of tonsilitis)
What is Sepsis?
Systemic inflammatory response to infection marked by characteristic haemodynamic disturbance and organ dysfunction
What is Severe Sepsis?
Sepsis with signs of hypoperfusion, hypotension or organ dysfunction
What is Septic Shock?
Sepsis with refractory hypotension
What can splenic malfunction/absence cause?
Humoral immunodeficiency + impaired clearance of encapsulated bacteria (Pneumococcus, H. influenzae, Meningococcus)
What is the Cardiac Output equation?
CO= HRxSV
What is the Delivery of O2 equation?
DO2 = CO x [ArtO2]
Where is 2/3 of blood located?
In veins and venules
Where does most of the TPR come from?
Arteries and Arterioles
What do arterial dilators decrease?
TPR (and therefore BP)
What do veno dilators decrease?
SV (and therefore CO–>BP)
What are the effects of adrenaline?
Low dose-> β1 (HRxSV=CO)
High dose -> α1 (vasoconstriction)
What are the effects of noradrenaline?
Potent vasoconstrictor
Significant s/e profile (necrosis of finger tips, toes)
What is the action of nitrates (e.g. GTN)?
Produces NO -> increased cAMP -> reduced Ca
Venous dilation -> ↓Venous Return
↓Preload -> ↓Myocardial Oxygen Demand
What procoagulant-anticoagulant balance disturbances occur in shock?
↑Tissue Factor Production (↑pro-coag)
↓Plasminogen activator inhibitor, thrombodulin, protein C (↓anti-coag)
What are the types of hypersensitivity reactions?
Type I - Immediate Hypersensitivity (hay fever, anaphylaxis)
Type II - Antibody-mediated (myasthenia gravis, Graves)
Type III - Immune complex-mediated (RA, SLE)
Type IV - Cell-mediated (contact dermatitis, transplant rej)
