Shock Flashcards
How do you assess for the presence of shock / tissue hypoperfusion?
Level of consciousness
Temperature of peripheries
Urine output
Serum lactate
Serum acid-base status
How do you distinguish distributive shock from other forms of shock?
Peripheries will be warm.
In cardiac, hypovolaemic, and obstructive shock, the peripheries are generally cold.
How do you distinguish obstructive shock from other forms of shock?
JVP and CVP will be markedly raised.
In cardiac, hypovolaemic, and obstructive shock, the JVP and CVP are reduced.
How do you estimate preload in ICU?
JVP or CVP
What are the two most common causes of shock in ICU?
Distributive shock (due to sepsis)
Hypovolaemic shock
How can coronary perfusion be improved in cardiogenic shock?
Definitive therapy:
- angioplasty and stenting
- coronary artery bypass grafting
- thrombolysis
Supportive therapy:
- Increasing diastolic pressure with vasopressors (norepinephrine preferred)
- Judicious small fluid boluses
What volume resuscitation should be used for mild to moderate blood loss?
If a patient has lost less than one litre, blood loss should be replaced by a colloid or balanced crystaloid.
This is because blood transfusion carries inherent complications.
Can dextrose be used as volume replacement?
Dextrose does not offer significant expansion of intravascular volume.
This is because it is quickly distributed throughout body fluid compartments.
Name an important clinical finding in patients with suspected cardiac tamponade
Pulsus paradoxus (an exaggerated fall in blood pressure during inspiration - more than 10mmHg).
What is the definitive therapy for PE?
Relieving the obstruction.
Intravenous thrombolysis with tissue plasminogen activator is probably the treatment of choice.
All patients should receive anticoagulation with intravenous unfractionated heparin or subcut LMWH
How long does it take for vasopressors to act?
Most achieve steady state within 15 minutes of infusion.
What are the charcteristics of dopamine?
Short acting
Inotropic
Chronotropic
Vasoconstricting
Risks and limitations of dopamine?
Arrhythmias
Can only be used through a peripheral cannula for a short period (risk of skin necrosis if the cannula tissues)
What are the characteristics of norepinephrine?
Potent vasoconstrictor
Minor inotropic/chronotropic effects.
What are the characteristics of epinephrine?
Similar to norepinephrine, but has greater chronotropic and inotropic effects.
Causes less vasoconstriction.
Should be given immediately in life-threatening shock. Give in 0.1mg boluses until severe hypotension is reversed.
