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31 Cards in this Set
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What is shock |
Insufficient perfusion and oxygen delivery to vital organs and tissues throughout the body. (essentially failure if the cardiovascular system and vital organ shut-down). Life threatening requiring rapid assessment and treatment and varies with each patient: in the elderly. |
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What are the three different types of Shock with examples of each? |
1. Pump dysfunction
a) Cardiogenic shock (heart stops pumping with pulmonary oedema)
b) Obstructive shock (pulmonary embolism stopping blood flow)
2. Pipe dysfunction - profound vasodilation, overall blood volume the same but sitting in vessels or in tissue [oedema])
ie. anaphylactic, neurogenic, septic.
3. Tank dysfunction
Hypovolaemic shock (bleeding out or vomiting - losing liquid.) |
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What are the 3 stages of Shock? |
a) Compensatory shock: which triggers the SNS response, immune response and hormonal response. b) Progressive shock c) Irreversible shock (dead) |
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Compensatory response: how does the SNS become activated |
1) Decrease CO effecting the blood volume & pumping into arterial system. 2) Low BP unable to maintain adequate perfusion of tissues. 3) Neural, hormonal and chemical compensatory mechanisms initiated to restore homeostasis. |
The same for all types of shock |
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What is the first vital sign to indicate shock and why? |
Respiratory Rate! SNS- baroreceptors and chemoreceptors detect lowered BP send nerve impulses to the vasomotor centre in medulla oblongata Causes vasoconstriction in skin, kidneys and GI tract BUT vasodilation in lungs, skeletal muscle and heart. Releases adrenaline and noradrenaline cause increased RR, HR, diaphoresis and dilated pupils. |
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How does vasoconstriction effect the body in shock? |
It may initially restore arterial BP but it will also increase peripheral resistance leading to increased workload of the heart |
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Describe the Immune response in compensatory shock? |
proinflammatory mediators (intended to fight foreign antigens and promote wound healing) are released.
mediators proliferate and damage the endothelium. Neutrophils adhere to damage causing clotting.
Small clots disrupt blood flow, damage to endothelium makes them leaky. Water and plasma proteins create oedema |
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What is the 1st hormonal response work in compensatory shock? |
SNS stimulated the adrenal gland to release ACTH hormone (adrenocorticotrophic) Gland to release more adrenaline and aldosterone. This aldosterone tells kidneys to retain salt in response to the low circulating blood volume ie it will try and reabsorb or retain water. |
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What is the 2nd hormonal response to compensatory shock? |
This stimulates the posterior pituitary gland releasing the antidiuretic hormone ADH. At this point Will have decreased urine output and require antidiuretic drugs |
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What is the 3rd hormonal response to compensatory shock? |
Thyroxine (which increases metabolic rate) and also sensitises receptors in the heart to noradrenaline.
This increase in sensitivity to noradrenaline helps increase the HR and SV (CO) therefore increasing BP. |
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Describe the 2nd stage of Shock - Progressive shock |
Continued hypoperfusion of organs creating lactic acid and Metabolic Acidosis (pH <7.35).
Following this is continued vasoconstriction causing ischaemia of extremities.
Lungs have pulmonary oedema causing hypoxaemia.
Myocardial workload becomes unsustainable causing Heart Failure.
Kidneys - unable to filter, reabsorb and excrete fluid normally. Acute tubular necrosis may occur. High increase in creatinine and urea.
Brain = decreased consciousness/restlessness/confused
GI Tract = gut might leak bacteria and toxins into circulation |
Multi organ failure |
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What is Stage 3 shock: |
Irreversible = death. Characterised by continued drop in BP and HR (decreased CO) resulting in multi-organ failure. |
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What can cause cardiogenic shock? |
myocardial infarction, cardiomyopathy, valve disease, structural defects, cardiac arrthymias. |
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What can cause obstructive shock? |
Cardiac tamponade, pulmonary embolism, tension pneomothorax |
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What can cause Hypovolaemic shock? |
External and internal fluid volume loss; haemorrhage; burns; GI losses |
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What causes anaphylactic shock |
Repeated exposure to an antigen |
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What causes septic shock |
Gram + or gram - bacteria |
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What causes neurogenic shock |
Spinal injury; spinal anaesthesia; brain injury; vasomotor depression; drug overdose; severe pain. |
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What do anaphylactic, septic and neurogenic shock all have in common? |
They are all considered distributive shock with widespread vasodilation to a response (antigen, infection or injury) |
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Apart from increased RR what is the next big vital sign to indicate shock? |
High HR with low BP and decreased urine output |
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Factors for Hypovolaemic shock |
Has the pt experienced multiple trauma? Has the pt had surgery recently? Has the pt suffered severe burns? Is the pt post partum? Does the pt have a history of oesophageal varices or peptic ulceration? Is the pt taking anticoagulant therapy? |
Questions to ask of the patient |
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Factors for risk of cardiogenic shock? |
Has the pt experienced any chest pain or suffered an MI recently? Especially in vessels supplying the anterior wall of the left ventricle? Does the pt have a history of cardiac failure or cardiac dysrhythmias? |
Questions to ask the patient |
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Factors for neurogenic shock? |
Does the pt suffer from any disordered state resulting in impaired nervous stimuli to vascular smooth muscle? Has the patient experienced recent spinal anaesthesia? Haste patient experienced trauma to the brain and/or spinal chord |
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Factors for septic shock? |
Does the pt have impaired immunity eg are they suffering HIV or cancer or undergoing chemotherapy? Does the pt have a deep-seated infection? Is the pt seriously ill and requiring multiple invasive catheters and devices? |
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Monitoring the pt in shock |
A - secure airways B - RR, very sensitive indicator of deterioration. Continuously monitor 02 says with pulse oximetry. C - manual assessment of radial arterial pulse for rate, rhythm, 'bounding' strong or threads, weak. ECG monitoring if if in ICU/CCU. C - central venous pressure (CVP) monitoring D - Glasgow Coma Scale (GCS) or AVPU E - renal function - urinary catheter, accurate fluid balance chart, urine dipstick. E - temperature measurement, observe skin colour, capillary refill. Lab and diagnostic tests. |
Altered ABCDE |
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Management of Hypovolaemic shock? |
Intravenous (crystalloid fluid - normal saline) fluid resuscitation to restore circulating volume. Identify and correct the cause. Colloid/blood as required adrenaline/noradrenaline for vasoconstriction (raise BP). |
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Particular management of cardiogenic shock? |
B) High oxygen therapy Inotropes - adrenaline, to increase strength of myocardial contraction. C) Vasodilator eg glycerol trinitrate - to reduce workload of heart and therefore O2 demand. D) Pain control - usually IV morphine, also has vasodilation properties. |
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Particular management of neurogenic shock? |
Medical management - restore sympathetic tone by stabilising spinal cord injury or proper positioning of the pt. Due to loss of SNS activity need to be mindful of risk of bradycardia and DVT Daily check of legs for pain, redness, tenderness, warmth Passive range of motion of legs eg with compression devices plus antithrombotic agent (heparin) Pt with spinal injury also needs to be closely watched for Hypovolaemic shock |
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Particular management of septic shock? |
Goals to achieve: CVP 8-12mmHg, central venous O2 says >70% or mixed venous O2 says >65% Fluid challenges to restore CVP. Inotropes (increase myocardial contractility ie noradrenaline) if required. Establish cause - blood cultures and cultures of potential infection entry sites |
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What is some psychological support for shock pts? |
Recognise and consider the emotional and psychological distress Management of anxiety - driver for stress response Reassurance and information Family/significant others, psychological support. May need to discuss end of life support. |
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Focus on recovery after shock? |
Pts who survive shock may not be able to get out of bed for a long time and are likely to have a prolonged, slow recovery. Educate pt and family about strategies to prevent further episodes Educate the need to gradually increase mobilising Refer to community nursing/occupational therapy/ physiotherapy as required. |
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