Shock and Haemorrhage Flashcards
What is shock?
A syndrome in which tissue perfusion is inadequate for the tissue’s metabolic requirement.
What are surrogate markers for tissue perfusion?
Blood pressure
Consciousness (Brain perfusion)
Urine output (Renal perfusion)
Lactate (General tissue perfusion) – quite a late sign of general tissue hypoperfusion and hypoxia
MAP=
CO x SVR
5 types of shock?
hypovolaemic cariogenic distributive (e.g. septic, anaphylactic, neurogenic) obstructive endocrine
What is the most common cause of shock?
sepsis
Explain what causes re-perfusion injury?
multifactorial
due to inflammatory response to shock, haemodynamic changes, loss of vascular reactivity and myocardial dysfunction
What sign is most frequently associated with all types of shock?
hypotension
What additional signs may be present in someone with cariogenic shock?
signs of myocardial failure
What additional signs may be present in someone with distributive shock?
raised JVP, pulses paradoxes, signs of the cause
e.g. if sepsis, pyrexia, rapid cap refill, hypotension
anaphylactic- vasodilatation, erythema, bronchospasm, oedema
Describe some clinical monitoring you can do for shock?
Examination – Pale, cold skin, prolonged capillary refill.
Urine output – Sensitive indicator of renal perfusion
Neurological – Disturbed consciousness a good indicator of cerebral hypoperfusion
Biochemical – Acidosis, lactate levels
Overview of management of shock?
Prompt diagnosis, and treatment critical
ABC approach
Establishment of reliable, wide bore IV access and resuscitate while investigating
Identify – and treat – underlying cause
Describe what is a good fluid challenge for someone with suspected shock?
Rapid administration of a fluid, with an assessment of response
Rapid enough to get a response, but not so fast as to provoke a stress response.
Typically – 300-500ml over 10-20 mins.
Describe the 3 types of fluid?
Crystalloids (normal salines, hartmans/ ringers lactate) – Convenient, cheap, safe (basically water and salts)
But: Rapidly lost from circulation to extravascular spaces, need significantly larger volumes than loss.
Colloids (isoplex, albumin) – Cheap(ish), reduce volumes required
But: Can cause anaphylaxis, no evidence of benefit vs crystalloids
Blood (technically a colloid but a special colloid) – oxygen carrying capacity, will stay in circulation.
But: a scarce resource, and multiple risks
When is pharmacological management for shock considered?
in severe cases
when fluids dont work or stop working
List some examples of drugs that may be used for pharmacological management of shock?
adrenaline noradrenaline (first choice in most circumstances) vasopressin dopamine dobutamine/ dopamine
What are the side effects of fluid resuscitation?
Resucitation associated with significant (sometimes massive!) fluid administration and positive balances
Volume delivered never remains intra-vascular
Extra-vascular overload, in an intra-vascularly
“dry” patient.
Sub-cutaneous oedema obvious
Less obvious – “wet” lungs/ARDS, bowel oedema, etc
> it is important to remove extra fluid from a patient once their shock has resolved - either spontaneously (ie they pee it out) or with diuretics or dialysis
Give an overview of what a massive haemorrhage protocol looks like?
call blood bank and state massive haemorrhage
send urgent samples for crossmatch and other blood tests
blood bank will issue 4 units red cells, 4 units FFP, 1 unit platelets
resus patient with ABCDE approach, call for senior help, transfuse the platelets and red cells
treat underlying cause
Explain the blood component support of a massive haemorrhage?
Red cells- maintain tissue oxygenation
FFP- replace coagulation factors and help maintain coagulation close to normal
Platelets
Crytoprecipitate- replace fibrinogen
Aim 2 RBC: 1 FFP in first instance and 1:1 in trauma
Specific management of PPH?
tranexamic acid
identify cause- like uterine atony
give uterotonics e.g. syntocinon
pay specific attention to fibrinogen which should be higher in pregnant women so there is a lower threshold for replacement
Specific management of pelvic trauma?
Imaging – where is he bleeding from
Pelvic binder to support pelvis
Tranexamic acid
Surgical involvement
1:1 ratio to red cells and FFP for trauma
Worried about DIC/ TIC risk from massive trauma
Specific management of variceal bleed?
Resus- consider intubation, high flow O2, intravenous access, blood transfusion, antibiotics, terlipressin
Endoscopy
Variceal band ligation, balloon tamponade if cant control bleeding
TIPS- transjugular intrahepatic portosystemic shunt
Prophylaxis- beta blockers
Specific management of ruptured AAA?
CT then surgery
Blood support is used to get the patients to theatre
