Shock

Question 1

Define ‘shock’

Answer 1

a potentially life threatening syndrome characterised by inadequate tissue perfusion, resulting in impaired cellular respiration and functioning

Question 2

Define healthy tissue perfusion

Answer 2

cells can use the oxygen to convert glucose to energy (ATP). This ATP is then used by the cells to carry out their metabolic activities. The process is called cellular respiration
adequate oxygen perfusion allows for aerobic metabolism, inadequate oxygen perfusion becomes anaerobic metabolism

Question 3

What is the difference between aerobic metabolism and anaerobic metabolism?

Answer 3

aerobic is efficient and produces 36 units of ATP (energy), opposed to anaerobic metabolism, which produces only 2 units of ATP and produces lactic acid which harms cells

Question 4

What is the cellular respiration equation?

Answer 4

C6H12O6 + 6O2 –> 6CO2 + 6H2O + ATP (36 molecules)

Glucose + Oxygen –> Carbon Dioxide + Water + Energy

Question 5

Outline the effect of impaired oxygen perfusion on the body

Answer 5

impaired oxygen -> anaerobic metabolism triggered -> decreased ATP production -> loss of cell membrane permeability -> NA+/K+ pump lost -> fluid shifts -> lysosomal enzymes released -> cellular death and organ failure

Question 6

Outline the effect of impaired glucose on the body

Answer 6

impaired access to and use of glucose by the cell -> access other sources of energy -> increasing acidosis -> protein depletion -> impaired cellular metabolism

Question 7

What are the three stages of shock?

Answer 7

Compensatory stage, progressive stage, and irreversible/refractory stage

Question 8

Define the compensatory stage of shock

Answer 8

Compensatory mechanisms activated:
>decreased CO stimulates receptors
>Adrenaline and noradrenaline released
Blood flow to most essential organs (heart & brain) maintained
>decreased blood flow to kidneys, GIT, lungs and skin
>renin-aldosterone system activated
>antidiuretic hormone (ADH) released
If corrected patient can recover from this stage

Question 9

Define the progressive stage of shock

Answer 9

Compensatory mechanisms fail
Decreased ATP production, Hypoxia of vital organs, Decreased cellular perfusion and tissue ischemia, Metabolic acidosis, Decreased cardiac output, Myocardial ischemia. Increased risk of gastric trauma, Increased risk of developing disseminated intravascular coagulation (DIC) (abnormal clotting), Acute renal failure
Aggressive management required to prevent multiple organ dysfunction syndrome (MODS)

Question 10

Define the irreversible/refractory stage of shock

Answer 10

Compensatory mechanisms are overwhelmed
Severe tissue hypoxia with ischemia, necrosis and death of the cell occurs
Build up of toxins
Multi-organ failure
Recovery unlikely

Question 11

What are the four types of shock?

Answer 11

Hypovolaemic shock (loss of intravascular volume)
Cardiogenic shock (pump failure)
Distributive shock (systemic vasodilation)
Obstructive shock (physical obstruction of blood circulation)
These can occur in isolation or in combination (Multifactorial shock)

Question 12

What are the three types of Distributive shock?

Answer 12

Septic shock (infection), anaphylactic shock (allergic reaction), neurogenic shock (spinal cord injury potential complication)

Question 13

Outline hypovolaemic shock

Answer 13

Caused by a loss of fluid. This can be from whole blood (haemorrhage), plasma (burns) or interstitial fluid (vomiting, diaphoresis). Shock begins to develop when the total circulating volume is decreased by approximately 15%

Question 14

What are clinical manifestations of hypovolaemic shock

Answer 14

anxiety, tachypnoea, hypotension (may be HTN at first due to compensatory measures), tachycardia, weak peripheral pulses, clammy moist skin, thirst, acidosis

Question 15

Outline cardiogenic shock

Answer 15

occurs from cardiac pathology causing inadequate cardiac output leading to tissue hypoxia. Cardiogenic shock occurs in the presence of ADEQUATE intravascular volume
Causes include reduced contractility, inadequate filling, arrhythmia, and failure of forward flow

Question 16

What are clinical manifestations of cardiogenic shock?

Answer 16

increased WOB, elevated RR, crackles/acute pulmonary oedema (APO), tachycardia, hypotension, distended neck veins, clammy skin, prolonged cap refill, decreased urine output, confusion

Question 17

Define distributive shock

Answer 17

results from excessive vasodilation and impaired distribution of blood flow.
There are three types of distributive shock: Septic shock, Anaphylactic shock, Neurogenic shock

Question 18

Define septic shock

Answer 18

Occurs when a patient develops sepsis: a life threatening condition of bacteria has entered in the bloodstream which triggers an inflammatory response.
Septic shock will develop when this response causes widespread vasodilation, tachycardia, decreased myocardial contractility and decreased tissue perfusion

Question 19

What are clinical manifestations of septic shock?

Answer 19

Tachypnoea, Hypoxia, Hypotension, Systemic oedema, Tachycardia, febrile, Decreased urine output, Hot clammy skin, Confusion

Question 20

Outline anaphylactic shock

Answer 20

anaphylaxis is reportable to the government
Anaphylactic shock is a result of a systemic hypersensitivity reaction. The patient has an antigen-antibody response. A large number of inflammatory mediators are released. This causes there to be a gross immune and inflammatory response. The symptoms are often sudden and severe
anaphylactic shock can be acutely fatal if smooth muscle contraction of the airways occurs

Question 21

What are clinical manifestations of anaphylactic shock?

Answer 21

Angioedema (swelling of the deeper layers of the skin, caused by a build-up of fluid), Stridor (wheezing), Dyspnoea, Bronchospasm and wheeze, Hypotension and cardiovascular collapse, Abdominal cramps, Diarrhoea, Flushing or pallor, Urticaria (hives), Coagulopathy

Question 22

Outline neurogenic shock

Answer 22

Occurs when sympathetic vascular tone is lost; from severe injury to the nervous system.
An imbalance occurs between the sympathetic and parasympathetic stimulation of vascular smooth muscle and this results in massive vasodilation without compensation

Question 23

What are clinical manifestations of neurogenic shock?

Answer 23

Hypotension, Bradycardia, Hypothermia

Question 24

Outline obstructive shock

Answer 24

occurs when a blockage or disruption of a major vessel in the systemic, pulmonary or circulatory systems occurs and interferes with cardiac output. Stroke volume is reduced, leading to a decrease in cardiac output, inadequate tissue perfusion and impaired cellular metabolism
common causes are: cardiac tamponade, tension pneumothorax, pulmonary embolisms

Question 25

What are some examples of cardiogenic shock?

Answer 25

AMI (acute myocardial infarction AKA heart attack), cardiomyopathy (heart muscle disease)

Question 26

What are some examples of hypovolaemic shock?

Answer 26

trauma, gastroenteritis (acute GIT inflammation leading to vomiting & diarrhoea)

Question 27

What are some examples of distributive shock?

Answer 27

Sepsis, anaphylaxis

Question 28

What are some examples of obstructive shock?

Answer 28

PE (blood clot prevents blood flow to the lungs), cardiac tamponade (fluid build-up in pericardial sac)

Question 29

What is the relation ship between hypovolaemic shock and fluid loss?

Answer 29

patients can compensate for losses of up to 15% 15-30% -> SNS activated, increased HR, CO and RR >30% - compensatory mechanisms begin to fail >40% - irreversible tissue damage occurs

Question 30

What is the pathophysiology of hypovolaemic shock?

Answer 30

decreased blood volume -> decreased venous return -> decreased stroke volume -> decreased cardiac output -> decreased tissue perfusion

Question 31

What are some causes of hypovolaemic shock?

Answer 31

External fluid losses: trauma, vomiting/diarrhoea, diabetes, diuresis Internal fluid losses: dehydration, burns, ascites, peritonitis

Question 32

What are some management considerations for hypovolaemic shock?

Answer 32

Provide oxygen therapy, assess for source of fluid loss, control external bleeding/fluid loss, IV fluid therapy, assess BGL, prevent hypothermia, consider blood products if required

Question 33

What is the pathophysiology of anaphylactic shock?

Answer 33

allergen -> release of vasoactive mediators -> 1. massive vasodilation -> hypovolaemia 2. increased capillary permeability -> fluid shifts to interstitial space -> widespread oedema -> respiratory distress/airway obstruction

Question 34

What are some management considerations for anaphylactic shock?

Answer 34

remove source of anaphylaxis if possible (eg. IV infusion) assess for level of consciousness, monitor for airway compromise: drooling, swelling, wheezing ect. Suction/nebulised adrenaline/prepare for intubation or tracheostomy if needed Provide oxygen/bronchodilators/corticosteroids if needed consider fluid resuscitation, provide adrenaline, may need to consider vasopressors

Question 35

Outline anaphylactic shock management via adrenaline

Answer 35

Child >12 years = 500mcg IM adrenaline Child 6-12years = 300mcg IM adrenaline Child <6 years = 150mcg IM adrenaline (repeat dose after 5 mins)

Question 36

Outline Anaphylaxis management

Answer 36

ASSESS FOR: upper airway obstruction (stridor, oral swelling), lower airway obstruction (wheeze, respiratory distress), shock (dizziness, pale, clammy) CALL FOR HELP CARDIAC ARREST? if YES - begin basic life support if NO- Adrenaline IM: adults 0.5mg, child 10mcg/kg repeat every 5 mins as needed Attach cardiac monitering, high flow oxygen, and place IV access (for SHOCK: 0.9% saline rapid infusion - 1000ml adults, 20mL/kg children) Consider -> further saline, nebulised adrenaline, adrenaline infusion, nebulised salbutamol

Question 37

What are risk factors for septic shock?

Answer 37

Age (<1 year - >65 years), malnutrition, chronic medical conditions, traumatic injury, invasive devices, wounds, surgery

Question 38

What are some management considerations for septic shock?

Answer 38

remove routes of infection, optain path samples, strict asepsis, control hyperglycaemia, broad spectrum antibiotics, temperatur regulation, treat symptoms fluid resuscitation, monitor response, Central venous access if required

Question 39

Outline initial resuscitation for septic shock

Answer 39

MEDICAL EMERGENCY 1. measure lactate level (remeasure if elevated >2mmol/L) 2. obtain blood cultures 3. administer broad spectrum antibiotics 4. begin rapid administration of 30 mL/kg crystalloid for hypotension or lactate >4 mmol/L 5. apply vasopressors if hypotensive during or after fluid resuscitation to maintain mean arterial pressure >65mmHg (MAP)

Question 40

What causes cardiogenic shock?

Answer 40

ineffective forward motion of blood

Question 41

what is the pathophysiology of cardiogenic shock?

Answer 41

1. ineffective ventricular emptying -> increased pulmonary pressures -> pulmonary oedema -> decreased oxygenation 2. decreased stroke volume -> decreased cardiac output = decreased cellular oxygen supply -> ineffective tissue perfusion -> impaired cellular metabolism

Question 42

Outline management of cardiogenic shock

Answer 42

secure airway if needed, monitor airway, assess for tachycardia/arrhythmias, hypotension, cool clammy skin. improve cardiac function via mechanical or inotropes (drugs that tell your heart muscles to beat or contract with more power or less power- eg. adrenaline/noradrenaline) Check BGLs

Question 43

What is the pathophysiology of obstructive shock?

Answer 43

structural compression -> reduced venous return -> reduced stroke volume -> reduced cardiac output -> reduced tissue perfusion -> reduced oxygen availability to cells = impaired cellular metabolism

Question 44

Outline the primary goal of obstructive shock management

Answer 44

to identify and relieve the cause of the block Eg. decompression for a tension pneumothorax, chest drain for a hemopneumothorax, thrombolytic therapy for a PE

Question 45

Define a central venous catheter

Answer 45

a long catheter inserted under sterile technique with local anaesthetic. It is inserted into a large vein until the tip reaches the superior vena cava (near the right atrium of the heart) Most commonly used veins: subclavian, internal, jugular, external jugular, femoral (less common)

Question 46

What are indications for a CVC?

Answer 46

Administer large volume of fluids, Long term access, Multiple drug administration, Administer irritating medications, Administer total parenteral nutrition (TPN), Difficulty obtaining other access, Provide access for transvenous pacing or pulmonary artery (PA) catheter

Question 47

List some examples of CVCs

Answer 47

hickmans, port-a-cath, PICC

Question 48

What are potential complications for a CVC?

Answer 48

During insertion: Pneumothorax, Haemothorax, Air embolus, Arterial cannulation, Incorrect positioning, Arrhythmia, Cardiac injury, Bleeding, Nerve injuries Post insertion: Haemorrhage, Subcutaneous emphysema, Thrombosis, Sepsis, Infection, Extravasation

Question 49

Outline nursing considerations for a CVC

Answer 49

Check integrity regularly, infusions must be done via pump, flush all ports that are not in use, ensure dressing is intact, assess for signs of infection, dont do BP on an arm with a PICC insitu, sterile technique must be used