Trauma Triad Flashcards
What are the 3 ‘components’ of the trauma triad?
Hypothermia
Coagulopathy
Acidosis
Under what temperature is a patient HYPOthermic?
<35C
How does the body generate heat?
Metabolism in muscle and livers
What are 5 means of heat loss?
- Conduction
- Convection
- Radiation (60%)
- Evaporation
- Respiration
What are some risk factors in patients for developing hypothermia?
ET tube, Trauma score, Low BP, Fluid bolus, head trauma and clothing (lack of)
Where are thermoreceptors?
Skin and Hypothalamus
Where is the thermal control centre?
Preoptic area of the hypothalamus
What are mechanisms to help increase body temperature?
- Vasoconstriction
- Adrenaline and NA release
- Shivering
- Increase in metabolic rate
How can haemorrhagic shock cause hypothermia?
A loss of blood volume
How can a brain injury lead to hypothermia?
Distruption of the central control centre
How can intoxication lead to hypothermia?
Peripheral vasodilation leads to heat loss
How can exposure lead to hypothermia?
Increased radiant heat loss
How can burns lead to hypothermia?
Skin damage leading to a loss of fluid and plasma
How can the administration of IV fluids lead to hypothermia?
Temperature of fluids leads to cooling of circulating fluid
What ECG changes are seen in hypothermia?
J wave (due to increased Calcium) ST elevation (early repolarisation)
How is it best to warm patients prehospitally?
Dry the patient
Cover the patient
Cover wounds and burns
Increase the surrounding temperature
How can hypothermia cause coagulopathy?
A reduction in enzyme activity and the decrease in activity of clotting factors and platelets
Why must you be cautious when administering drugs to hypothermic patients?
A reduction in metabolism and elimination leads to slower responses. This means it is possible to overdose these patients more easily
What is ‘normal coagulation’ defined as?
A complex set of reactions that form blood clots preventing haemorrhage
What is normal coagulation dependent on?
Temperature (HYPOTHERMIA) Blood pH (ACIDOSIS)
What two things are essential for coagulation?
Calcium ions and Platelets?
What are the two coagulation pathways?
Extrinsic
Intrinsic
What causes the extrinsic pathway to be activated?
Tissue Trauma
What causes the intrinsic pathway to be activated?
Blood/Vessel trauma
Collagen fibre and platelet exposure
What is produced to activate the extrinsic pathway?
Tissue Factor
calcium
What is produced to activate the intrinsic pathway?
Activated clotting factor 12 and Activated platelets
calcium
Prothrombinase catalyses what reaction?
Prothrombin –> Thrombin
What does thrombin catalyse?
Fibrinogen –> Fibrin
What 5 things can loss of blood lead to in coagulopathy?
- Loss of clotting factors
- Haemodilution (fluids)
- Hypothermia (clotting and enzymes)
- Acidosis (clotting, enzymes and platelets)
- Hypocalcaemia (haemodilution)
What is blood calcium essential for?
Normal clotting mechanisms
What is normal blood pH?
7.35-7.45
Under what blood pH is it considered ‘acidosis’?
<7.35
What 3 mechanisms are used to regulate blood pH normally?
- Renal system (excreted H ions + reabsorbs HCO3)
- Respiration (expire CO2)
- Blood buffering
What is the Bohr effect equation?
CO2 + H2O –> H2CO3 –> HCO3- + H+ –> excretion
What are the two main ‘types’ of acidosis?
- Metabolic acidosis
2. Respiratory acidosis
How does metabolic acidosis occur?
Tissue hypoxia causes anaerobic metabolism to occur producing lactic acid which causes acidosis.
How does respiratory acidosis occur?
A reduction in respiratory rate leads to impaired CO2 expulsion. This leads to hypercapnia and thus acidosis.
What can cause respiratory acidosis (resp damage)?
- Trauma
- Drugs and alcohol
- Head injury
- COPD
What can cause metabolic acidosis?
- Blood loss
- Hypothermia
- Decreased cardiac output
How does the administration of NaCl worsen acidosis?
Cl ions reduce bicarbonate reabsorption
Cl ions affect ioinic balance
Dilution of coagulation factors
Acidosis (pH 4-5)
What is the equation for plasma pH?
[HCO3]/PCO2
