Sepsis and shock Flashcards
Definition of shock
Systemic failure of ATP production
Four types of shock
Hypovolaemic
Distributive
Cardiogenic
Obstructive
Mechanism of hypovolaemic shock
Decreased blood volume
E.g. Haemorrhage, severe dehydration
Mechanism of distributive shock
Vasodilation, unable to vasoconstrict appropriately, innappropriate pooling of circulating blood
E.g. sepsis, SIRS, anaphylaxis
Mechanism of cardiogenic shock
Failure of forward flow
E.g. systolic failure (reduced contractiliy), diastolic failure (reduced filling), dysrhythmias
Mechanism of obstructive shock
Mechanical obstruction of venous return
E.g. pericardial effusion, GDV
Types of circulatory shock
Compensated
Non-compensated
Compensated shock
Catecholamine release induces physiological responses to maintain delivery of oxygen to tissues.
Clinical signs of mild shock in dogs
HR: 130-150
MM colour: normal to pinker
CRT: rapid <1s
Pulse amplitude: increased
Pulse duration: mildly reduced
Metatarsal pulse: easily palpable
Clinical signs of moderate shock
HR: 150-170
MM: pale pink
CRT: Approx normal
Pulse amplitude: mild to moderate decrease
Pulse duration: Moderately reduced
Metatarsal pulse: just palpable
Clinical signs of severe shock
HR: 170-220
MM: grey, white, or muddy
CRT: slow (>2s) or absent
Pulse amplitude: severe decrease
Pulse duration: severely reduced
Metatarsal pulse: absent
Mentation often affected - obtunded
Shock in cats
Bradycardia and hypothermia
Treatment of hypovolaemic shock
Bolus fluids
Treatment of distributive shock
Bolus fluids
Vasopressors
Treatment of cardiogenic shock
Treat underlying cause
Treatment of obstructive shock
Relieve obstruction
First choice fluids for shock
Isotonic crystalloid fluid e.g. Hartmann’s
Typical fluid bolus may be 10ml/kg given over 15 mins
Parallel treatment to fluid bolus in shock patients
Oxygen supplementation
Fix underlying causes
Bleeding patients
fluids will dilute clotting factors.
Fluids still can be lifesaving in the short term but in the long term they are likely to need a blood transfusion.
Sepsis
Life-threatening systemic inflammation secondary to a dysregulated host response to infection
Sepsis parameters in cats
Temp: <37.8 or >39.7
RR: >40
HR: <140 or >225
WBC: <5103/μL or >19.5103/μL
Can be diagnosed if 2/4 are met
Sepsis parameters in dogs
Temp:
<37.2°C
>39.2°C
RR: >30 bpm
HR: >140 bpm
WBC:
<6103/μL
>19103/μL
>3% bands
3/4 parameters have to be met
Hallmark of systemic inflammation
Cytokine mediated inappropriate vasodilation
If source of infection not found which broad spectrum antibiotic shoudl you start with
Potentiated amoxicillin 20mg/kg 3x daily
Fluid therapy in septic patients in distributive shock
May respond to fluid resuscitation, but vasopressor therapy may be required to treat the inappropriate vasodilation e.g. norepinephrine
Vasopressor drugs
Norepinephrine
Dopamine
Dobutamine
Norepinephrine
Mild increase in cardiac contractility
Marked increase in vasomotor tone
Dose 0.1-2mcg/kg/min
Dopamine
Moderate increase in cardiac contractility
Moderate increase in vasomotor tone
Dose: 5-15 mcg/kg/min
Dobutamine
Moderate increase in cardiac contractility
Moderate increase in vasomotor tone
Dose: 5-20 mcg/kg/min
What endocrine imbalance is common in sepsis
Profound hypoglycaemia
Blood glucose should be measured at presentation and again if patient deteriorates
Can give diluted dextrose (1:3) IV in needed, and dextrose in fluids
