Shock And Haemorrhage Control Flashcards
Learning Objectives
- Define shock
- Identify clinical shock syndromes
- Compressible vs non compressible bleeding
- Relate casualty symptoms to underlying condition
- Discuss management principles
- Demonstrate shock management skills
- Sidenote: Steve said you likely won’t be asked to go into too much detail in the actual exam
What is shock?
The body’s reaction to inadequate tissue perfusion and oxygenation
List the different types of shock
- Hypovolaemic
- Cardiogenic
- Neurogenic
- Anaphylactic
- Septic
Describe the early pathology of shock
- Decreased venous return
- Reduction in cardiac output
- Hypotension
- Hypoperfusion, if uncorrected………
- Leading to Tissue hypoxia
What are the corrective mechanisms for shock?
- Fluid moves from tissues into blood vessels
- Increase in heart rate: Tachycardia - sympathetic response
- Vasoconstriction: Cold & pale - sympathetic response
- Reduced urinary output
Describe the late pathology of shock
- Anaerobic metabolism
- Production of lactic acid
- Metabolic acidosis
- Cellular oedema
- Tissue oedema
- Loss of organ function
- Cell death
- Leads to death
Describe Hypovolaemic shock
- lMost common cause of shock in war
- Due to FLUID LOSS: (haemorrhage / burns etc)
- Most amenable to prompt management
- Must be recognised early
Where is this blood from Hypovolaemic shock found?
- “Blood on the floor and 4 more”
- Chest
- Abdomen
- Pelvis & retroperitoneum
- Thighs - long bones
Where is this blood from Hypovolaemic shock found?
- “Blood on the floor and 4 more”
- Chest
- Abdomen
- Pelvis & retroperitoneum
- Thighs - long bones
What occurs as a result of the loss of circulating volume?
- Injury tissue -> Blood loss -> Oedema
- Not just blood loss
List the classifications of the circulating blood volume loss
- Class I: 0-15% - 750ml
- Class II: 15-30% - 750-1500ml
- Class III: 30-40% - 1500-2000ml
- Class IV: > 40% - 2000ml
How do you assess blood loss?
- Closed tibial fracture
- Wound size of adult hand
- Clot size of adult fist
- Coverage of 2m square on non porous surface
Give examples of assessing blood loss
- Closed femur fracture: 1.5 litres
- Fractured pelvis: 3 litres
- Hemithorax: 2 litres
- Fractured rib: 150 ml
Describe Class 1 Shock
- Heart rate: <100
- Systolic BP: Normal
- Pulse pressure: Normal
- Cap refill: Normal
- Resp. Rate: 14-20
- Urine output: >30
- Cerebral function: Normal /sl
- Mood: Anxious
Describe Class 2 Shock
- Heart rate: >100
- Systolic BP: Normal
- Pulse pressure: Narrowed
- Cap refill: Prolonged
- Resp. Rate: 20-30
- Urine output: 20-30
- Cerebral function:
- Mood: Anxious/Frightened/hostile
Describe Class 3 Shock
- Heart rate: 120 - 140
- Systolic BP: Decreased
- Pulse pressure: Narrowed
- Cap refill: Prolonged
- Resp. Rate: >30
- Urine output: 5-20
- Cerebral function:
- Mood: Anxious/Confused
Describe Class 4 shock
- Heart rate: >140
- Systolic BP: Very low
- Pulse pressure: Very narrow / abnormal
- Cap refill: Very long
- Resp. Rate: >35
- Urine output: negligible
- Cerebral function:
- Mood: Confused/unresponsive
What are some concerns about Hypovolaemic shock
- Beware of:
- The very old: Poorly tolerated
- The very young: Well compensated before signs start to appear
- The very fit: Well compensated before signs start to appear
What examinations can be performed to find out the types of shocks
- Primary survey: Identifies presence of bleeding + or - site
- Secondary survey: Identifies site of bleeding
- If the site is non compressible: You identify presence of bleeding, Surgeons identify what is bleeding
List the immediate assessments after shock
- Mental state - AVPU
- Respiratory rate
- Colour (pale & cyanosed) & temperature
- Capillary refill
- Pulse - rate & volume
- Blood pressure.
Give a quick guide to Blood Pressure
- BP 90 = Palpable radial pulse
- BP 80 = Palpable femoral pulse
- BP 70 = Palpable carotid pulse
What is the assessment and management of shock?
- Classical signs obvious: But are late in onset & equate to 1500ml or more blood loss
- Early signs are: Vasoconstriction (cold), Tachycardia, Narrow pulse pressure
- Assume shock if cold and has rapid pulse: ‘Rapid’ in a fit soldier may be < 100
What Resuscitation techniques can be used for shock?
- ABCD
- Establish, maintain, secure, protect airway
- Oxygen if available
- Ensure adequate ventilation
- Now assess and treat circulation: Stop the bleeding, Establish iv access, Restore lost volume
What are the management principles?
- Save life
- Prevent deterioration
- Promote recovery
Describe the “Stopping the bleeding” aspect of resuscitation for compressible haemorrhage
- Stop Bleeding
- Compressible haemorrhage: Limb fracture! External wounds, Pelvic fracture (to a degree)
- Management: Direct pressure, Indirect pressure, Correct use of tourniquet, Splintage
Describe the “Stopping the bleeding” aspect of resuscitation for non compressible haemorrhage
- Stop Bleeding
- Non compressible haemorrhage: Chest, Abdomen, Pelvis, Retroperitoneum
- Management: Urgent surgery
How is vascular access carried out
- Percutaneous access upper limbs
- Intravenous cutdown: Medial malleolus - long saphenous vein, Antecubital fossa
- Femoral vein cannulation: Seldinger technique
What can be used as a replacement of lost volumes?
- Crystalloids: All roles
- Colloids: All roles
- Blood: Roles 2 & 3
- But to do no harm: make sure it’s warm
Give some features of crystalloids as a use of replacement
- Immediate replacement of lost volume
- 3:1 rule
- Short duration
- Safe
- Initial challenge of two litres & reassess
- Challenge in a child - 20 ml/kg body weight
- Challenge may be repeated
Give some features of colloids as a use of replacement
- Immediate replacement of lost volume
- 1:1 rule
- Long duration
- Safe
- Initial challenge of one litre & reassess
- 10 ml/kg body weight in a child
- Forms a jelly when cold
List the principles of management (PART 1)
- Early recognition
- Early restoration of tissue perfusion:
- Stop the bleeding
- Compressible haemorrhage - YOU
- Non compressible haemorrhage - SURGEON
- Then Restore volume
- Resuscitation end point - systolic BP 90, Dilemma! - Closed HI, ideal systolic BP 120+
List the principles of management (Part 2)
- IV fluid resuscitation protocol
- With non compressible haemorrhage
- “Better a live casualty who has stopped bleeding & stabilised with a low BP without iv fluids, than one given iv fluids causing a transient rise in BP with re-bleeding that consumes what clotting factors remain. He then bleeds to death!
- A live clot or a dead bleeder? - You can’t stop the re-bleed
only a surgeon can!
What is the IV fluid resuscitation protocol
- If bleeding is non compressible and surgery not readily available, a low BP is better than no BP!
- If the radial pulse is present, curtail the fluid challenge or, don’t challenge at all
- But…monitor!…monitor!…monitor!
Provide the IV Fluid Resuscitation Protocol for Compressible + non compressible patients under shocked/unshocked conditions
- Compressible: Not shocked - no fluids
- Compressible: Shocked - IV fluids
- Non compressible: Urgent evacuation feasible - no fluids
- Non compressible: Urgent evacuation not feasible - IV fluids
- Apply common sense to these rules!
State the management of shock for compressible patients
Compressible -> Control -> IV -> Reassess -> Stabilise or Improves -> IV fluids to maintain radial pulse -> Surgery
State the management of shock for non compressible patients
- Non compressible -> Control -> IV -> Reassess-> Fails to improve or deteriorates -> Recognise the need for surgery
- Either (2 pathways from here) ->
- Immediate evacuation -> IV en-route if possible -> Surgery
- Delayed evacuation -> IV fluids to maintain radial pulse -> Surgery
List some supportive measures that can take place
- Treat hypothermia: Clotting mechanism is temperature sensitive
- Analgesia: Pain = agitation - worsens shock
- Fracture immobilisation: Controls blood loss & pain
- Tubes in orifice: Gastric dilatation
How can we monitor these patients?
- lPulse oximetry
- ABGs
- ECG & non-invasive monitoring
- End tidal CO2 (intubated casualties)
- Urinary output
List the management problems that can occur
- Continuing haemorrhage: From where
- Fluid overload: Pulmonary oedema, NB, beware blast lung
- Acid/base imbalance: Occurs but should be furthest form your mind in the early stages of management
List the other types of shock
- Cardiogenic
- Anaphylactic
- Neurogenic
- Septic
Briefly describe the causes of cardiogenic shock
- Cardiac tamponade
- Myocardial contusion
- Myocardial infarction
- Tension pneumothorax
- Pulmonary embolism
- Air embolism
Briefly describe the causes of anaphylactic shock
- Medications
- Allergens: Bronchospasm, Urticaria, Peripheral vasodilation
Briefly describe the causes and signs of neurogenic shock
- Causes: Brain stem injury, Cervical or high thoracic spine injury
- Signs: Hypotension & bradycardia, warm periphery, Rule out mixed aetiology before atropine
Briefly describe the causes and signs of septic shock
- Causes: Delayed evacuation! Penetrating abdominal injuries, vasodilation due to endotoxaemia
- Signs: Bounding pulse (Wide pulse pressure), Rule out mixed aetiology
Summary
- Hypovolaemic until proven otherwise
- High index of suspicion: Early signs subtle, especially young / fit
- Control of haemorrhage
- Compressible & non-compressible: Recognise the need for surgery early
- Sense of urgency is paramount
