management of shock in an injured patient.
Posted: 09 Jul 2012, 22:16
Shock
The initial step in managing the shock in an injured patient is to recognize its presence. The initial diagnosis is based on clinical appreciation of the presence of inadequate tissue oxygenation & organ perfusion. It is also defined as a situation when the circulation is inadequate for metabolic needs.
Principles of Shock Recognition and Management:
Patients in shock may only exhibit subtle signs
Identifying the cause is usually less important than starting treatment
Goal is to restore perfusion and correct the shock state
Frequent reassessment of response to treatment is important
Sole reliance on systolic blood pressure as an indicator of shock results in delayed recognition of shock. The Body's Mechanisms try to compensate for Shock until up to 30% of the patient’s blood volume is lost by increase cardiac output (tachycardia), increase oxygen supply (tachypnea) and release of vasoactive mediators which cause nausea and peripheral vasoconstriction (Cool, clammy skin, increased diastolic pressure, decreased urine output).
Types of Shock:
Shock in an injured patient may be classified as haemorrhagic or non-haemorrhagic. Recognition of the type of shock depends on history taking, clinical examination and selected additional tests; however, this should not delay aggressive volume resuscitation.
1/ Hemorrhagic Shock:
Definition: Acute loss of circulating blood; can be internal and / or external. It is the most common in trauma patients. Virtually all patients with multiple injuries have an element of hypovolaemia. Additionally, most other types of non-haemorrhagic shock respond partially or briefly to volume resuscitation. Therefore, treatment is usually instituted as if the patient is hypovolemic (always treat for hemorrhagic shock first). The small number of patients whose shock has aetiology can be identified and managed.
The Four Stages of Hemorrhagic shock:
Stage 1 haemorrhage - 0 to 15% of total blood volume (TBV)
Stage 2 haemorrhage - 15 to 30% of TBV
Stage 3 haemorrhage - 30 to 40% of TBV
Stage 4 haemorrhage - > 40% of TBV
2/ Non-hemorrhagic Shock:
Hypovolemic (non-hemorrhagic) shock
Due to vomiting , diarrhoea, "third spacing" of fluid
Treat with IV Lactated Ringers or saline
Does not need blood transfusion
Anaphylactic shock
Due to allergic reaction with release of vasoactive mediators which can cause airway oedema & vasodilatation
Treat with IV fluids & epinephrine
Septic Shock
Can be a late or delayed complication
Patient may have fever or hypothermia
Treat with IV fluids ; sometimes need secondary treatment with vasopressors
Finding and directly treating the source of the sepsis is critical to save the patient (start antibiotics, drain abscess if present, etc.)
"Obstructive" : key sign is distended neck veins in the patient with shock
Tension pneumothorax
Treat with anterior needle thoracostomy
Cardiac tamponade
Treat initially with IV fluids
Consider pericardiocentesis
Pulmonary embolus :
Need to confirm diagnosis (V/Q or CAT scan)
Then treat with thrombolytics or embolectomy
Cardiogenic : due to heart pumping dysfunction
Acute myocardial infarction (sometimes this can be the original cause of a person injuring themselves in a traffic accident or fall)
Myocardial contusion
Actually is rare even with major blunt chest trauma
May require treatment with vasopressors (dopamine)
Neurogenic : due to spinal cord injury and loss of sympathetic nervous system outflow
Results in venous pooling, peripheral vasodilatation
Often has relative bradycardia
Treat with IV fluids first, then alpha vasoconstrictors if hypovolemic shock ruled out
Spinal shock : actually is a "cord-stunning" syndrome
Flaccidity and loss of reflexes
Is an "electrical" phenomenon of the spinal cord
May have complete recovery
General Symptoms of Shock
General Signs of Shock
Weakness
Dizziness
Light-headedness
Nausea
Sense of impending doom Decreased mental status or confusion
Cool, clammy, or grey ashen colour skin
Diaphoresis
Tachycardia
Tachypnea
Hypotension
Oliguria
Rapid Fluid Resuscitation for Shock:
Place two large bore canulas (> 18 gauge).
Draw blood for type and cross-match from the needle stick for the IV line
Initially run fluid in "wide-open"
Use large drip chamber IV tubing
May need pressure bags on the IV bags
Usually use Lactated Ringers
Choose normal saline if patient may be hyperkalemic
Normal saline also preferred for same IV line to be used for blood transfusion
Do not use vasopressors ; treat with fluids
Other Resuscitative procedures for Severe Shock
Blood transfusion
Type - O-negative (if needed immediately)
Type - specific (if needed in < 15 minutes)
Fully cross-matched
Emergent left thoracotomy, pericardiotomy, aortic clamping
Auto transfusion
Most useful for blood output from chest tubes
Indications for Emergent Transfusion with O-Negative Blood
No palpable blood pressure at arrival
Multiple simultaneous patients requiring emergent transfusion
Rapid deterioration or sudden large volume external blood loss and type specific blood not immediately available
The initial step in managing the shock in an injured patient is to recognize its presence. The initial diagnosis is based on clinical appreciation of the presence of inadequate tissue oxygenation & organ perfusion. It is also defined as a situation when the circulation is inadequate for metabolic needs.
Principles of Shock Recognition and Management:
Patients in shock may only exhibit subtle signs
Identifying the cause is usually less important than starting treatment
Goal is to restore perfusion and correct the shock state
Frequent reassessment of response to treatment is important
Sole reliance on systolic blood pressure as an indicator of shock results in delayed recognition of shock. The Body's Mechanisms try to compensate for Shock until up to 30% of the patient’s blood volume is lost by increase cardiac output (tachycardia), increase oxygen supply (tachypnea) and release of vasoactive mediators which cause nausea and peripheral vasoconstriction (Cool, clammy skin, increased diastolic pressure, decreased urine output).
Types of Shock:
Shock in an injured patient may be classified as haemorrhagic or non-haemorrhagic. Recognition of the type of shock depends on history taking, clinical examination and selected additional tests; however, this should not delay aggressive volume resuscitation.
1/ Hemorrhagic Shock:
Definition: Acute loss of circulating blood; can be internal and / or external. It is the most common in trauma patients. Virtually all patients with multiple injuries have an element of hypovolaemia. Additionally, most other types of non-haemorrhagic shock respond partially or briefly to volume resuscitation. Therefore, treatment is usually instituted as if the patient is hypovolemic (always treat for hemorrhagic shock first). The small number of patients whose shock has aetiology can be identified and managed.
The Four Stages of Hemorrhagic shock:
Stage 1 haemorrhage - 0 to 15% of total blood volume (TBV)
Stage 2 haemorrhage - 15 to 30% of TBV
Stage 3 haemorrhage - 30 to 40% of TBV
Stage 4 haemorrhage - > 40% of TBV
2/ Non-hemorrhagic Shock:
Hypovolemic (non-hemorrhagic) shock
Due to vomiting , diarrhoea, "third spacing" of fluid
Treat with IV Lactated Ringers or saline
Does not need blood transfusion
Anaphylactic shock
Due to allergic reaction with release of vasoactive mediators which can cause airway oedema & vasodilatation
Treat with IV fluids & epinephrine
Septic Shock
Can be a late or delayed complication
Patient may have fever or hypothermia
Treat with IV fluids ; sometimes need secondary treatment with vasopressors
Finding and directly treating the source of the sepsis is critical to save the patient (start antibiotics, drain abscess if present, etc.)
"Obstructive" : key sign is distended neck veins in the patient with shock
Tension pneumothorax
Treat with anterior needle thoracostomy
Cardiac tamponade
Treat initially with IV fluids
Consider pericardiocentesis
Pulmonary embolus :
Need to confirm diagnosis (V/Q or CAT scan)
Then treat with thrombolytics or embolectomy
Cardiogenic : due to heart pumping dysfunction
Acute myocardial infarction (sometimes this can be the original cause of a person injuring themselves in a traffic accident or fall)
Myocardial contusion
Actually is rare even with major blunt chest trauma
May require treatment with vasopressors (dopamine)
Neurogenic : due to spinal cord injury and loss of sympathetic nervous system outflow
Results in venous pooling, peripheral vasodilatation
Often has relative bradycardia
Treat with IV fluids first, then alpha vasoconstrictors if hypovolemic shock ruled out
Spinal shock : actually is a "cord-stunning" syndrome
Flaccidity and loss of reflexes
Is an "electrical" phenomenon of the spinal cord
May have complete recovery
General Symptoms of Shock
General Signs of Shock
Weakness
Dizziness
Light-headedness
Nausea
Sense of impending doom Decreased mental status or confusion
Cool, clammy, or grey ashen colour skin
Diaphoresis
Tachycardia
Tachypnea
Hypotension
Oliguria
Rapid Fluid Resuscitation for Shock:
Place two large bore canulas (> 18 gauge).
Draw blood for type and cross-match from the needle stick for the IV line
Initially run fluid in "wide-open"
Use large drip chamber IV tubing
May need pressure bags on the IV bags
Usually use Lactated Ringers
Choose normal saline if patient may be hyperkalemic
Normal saline also preferred for same IV line to be used for blood transfusion
Do not use vasopressors ; treat with fluids
Other Resuscitative procedures for Severe Shock
Blood transfusion
Type - O-negative (if needed immediately)
Type - specific (if needed in < 15 minutes)
Fully cross-matched
Emergent left thoracotomy, pericardiotomy, aortic clamping
Auto transfusion
Most useful for blood output from chest tubes
Indications for Emergent Transfusion with O-Negative Blood
No palpable blood pressure at arrival
Multiple simultaneous patients requiring emergent transfusion
Rapid deterioration or sudden large volume external blood loss and type specific blood not immediately available