Critical Care - Shock

Question 1

What is shock?

Answer 1

is a syndrome condition resulting from inadequate tissue perfusion and impaired cellular metabolism leading to cell dysfunction, cell death and organ failure. Cells experience hypoperfusion since the demand for oxygen and nutrients are deprived.

Question 2

Decreased tissue perfusion can lead to:

Answer 2

hypoperfusion > impaired oxygen and glucose delivery > increasing cellular demand (oxygen and nutrients) and comsumption > impaired cellular metabolism

Question 3

types of shock

Answer 3

hypovolemic
cardiogenic
obstructive
distributive

Question 4

what is hypovolemic shock

Answer 4

caused by inadequate blood circulation volume or intravascular volume
oxygen delivery is impaired since RBC volume is decreased which carries oxygen

Question 5

causes of hypovolaemic shock

Answer 5

non-haemorrhagic (not bleeding) - fluid shift (oedema) and severe dehydration (vomiting, diarrhoea and burns)

haemorrhagic (bleeding) - trauma, GI bleed, postpartum (after giving birth)

Question 6

hypovolaemic shock transitions

Answer 6

decreased circulating volume > decreased venous return > decreased cardiac output > HYPOTENSION > decreased tissue perfusion > impaired cellular metabolism

Question 7

S&S of hypovolaemic shock

Answer 7

HR - Tachy (compensates to increase blood flow)
Pulse - weak and thready
BP - hypotension
CO - decreased
CVP - decreased
SVR - increased due to vasoconstriction
O2 sat - low (decreased tissue perfusion)
Skin and Temp - cyanotic, cool and pale skin. cap refill is > 3 secs

oliguria
confused and agitated mental state (decreased blood circulation in the brain)

Question 8

nursing treatments and intervention for hypovolaemic shock

Answer 8

Fluids and blood replacement
- crystalloids (normal saline) and colloids (albumin) if non-hemorrhagic
- RBCs or blood products for hemorrhagic

encourage fluids

Question 9

what is cardiogenic shock?

Answer 9

-caused by inadequate cardiac pump function leading to low CO and SV or HR
-heart cannot pump enough blood to meet normal tissue perfusion
-caused by myocardial damage
-blood volume is adequate, however, the heart pump function is impaired causing fluid accumulation in the lungs (pulmonary oedema)

Question 10

cardiogenic shock transitions

Answer 10

1. decreased CO > compensatory RAAS (renin angiotensin aldosterone system) > increased blood volume > increased preload, SV and HR > systemic and pulmonary oedema > dyspnea
2. decreased CO > compensatory catecholamine (neurohormone) > increased SVR, preload and HR > increased myocardial oxygen demand > decreased CO and EF (ejection fraction) > decreased tissue perfusion (ischaemia) > impaired cellular metabolism > myocardial dysfunction

Question 11

S&S of cardiogenic shock

Answer 11

HR - Tachy (compensates to increase blood flow)
Pulse - weak peripheral pulses
BP - hypotension
CO - decreased
CVP - increased
SVR - increased due to vasoconstriction
O2 sat - low (decreased tissue perfusion)
Skin and Temp - cool and clammy skin. cap refill is > 3 secs

oliguria
confused and agitated mental state (decreased blood circulation in the brain) or sense of impending doom
jugular vein distention
chest pain
dyspnea (due to pulmonary oedema)

Question 12

nursing intervention and treatment for cardiogenic shock

Answer 12

MI - agioplasty (procedure used to open blocked coronary artery)
thrombolytics (medication to dissolve blood clots)

Oxygen therapy

Vasopressors (adrenaline, dobutamine or dopamine) - increase vasoconstriction to increase blood circulation therefore increasing tissue perfusion

Diuretics - decrease heart workload and extra blood volume

Question 13

pathologic conditions that cause cardiogenic shock

Answer 13

acute MI - cardiomyopathy, sepsis, myocarditis, pericarditis, aneurysm, dysrhythmias (impaired diastolic filling), contusion (blood capillary injury), metabolic abnormalities and papillary muscle rupture

cardiac obstructions due to pulmonary embolism, cardiac tamponade (pressure in the heart due to fluid accumulation between heart muscle spaces and pericardium), valvular disorders, tumours and arterial wall ruptures or defects

Question 14

what is obstructive shock?

Answer 14

• CO is decreased as circulation is blocked into the heart and its vessels

Question 15

cause of obstructive shock

Answer 15

-pulmonary embolism (blocked pulmonary artery)
-tension pneumothorax (accumulation of air in the pleural cavity causing pressure in the lungs)
-pericardial tamponade (accumulation of fluid around the sac of the heart)
-abdominal compartment syndrome (increased pressure in the abdomen that restricts blood flow)

Question 16

nursing intervention and treatment to obstructive shock

Answer 16

-treating the cause of obstruction (surgical procedure)
-oxygen therapy and fluid resuscitation
-cardiac medications

Question 17

what is distributive shock? and its transitions

Answer 17

-caused by leaky and widespread vasodilation of the blood vessels leading to decreased peripheral vascular resistance or SVR and blood pressure, therefore leading to decreased tissue perfusion and relative hypovolemia.

septic (bacterial toxins) anaphylactic (antigen) neurogenic (decreased vascular tone) > release of chemical mediators > (myocardial dysfunction) (bronchoconstriction and vasodilation or vascular leakage) > excessive vasodilation > decreased peripheral vascular resistance > decreased CO > hypotension > decreased tissue perfusion > impaired cellular metabolism

Question 18

types of distributive shock

Answer 18

septic shock (severe infection)
anaphylactic shock (allergic reaction)
neurogenic shock (damage to nervous system)

Question 19

what is septic shock

Answer 19

-occurs when severe infection triggers the body a cascade of systemic inflammatory response (fever)
-oxygen demand and consumption of the cells are high impairing cellular metabolism
-glucose metabolism and consumption of cells will also increase

Question 20

causes of sepsis

Answer 20

pneumonia
urosepsis (untreated UTI)
bacteria
intra-abdominal infections (pancreatitis)
wound infection
invasive procedures
indwelling medical devices (catheters)

Question 21

pathophysiology of sepsis

Question 22

S&S of sepsis

Answer 22

HR - tachy
pulse - bounding
CO - increased (vasodilation)
BP - hypotension
CVP - low
SVR - low (vasodilation)
O2 sat- high, however can cause hypoxia due to deprived tissue perfusion
Skin and Temp- initially warm and flushed, however when BP drops skin becomes cool, pale and mottled
RR - high due to hypoxia

Question 23

nursing treatment and intervention for sepsis

Answer 23

-early detection and treatment of sepsis can prevent deterioration and death
-broad spectrum abx
-fluid resuscitation
-vasopressors (adrenaline)
-neuromascular blockade agents and sedation (decrease metabolic demands and provide comfort)
-stress ulcers medications (PPIs)

Question 24

what is anaphylactic shock?

Answer 24

occurs from severe allergic reaction where blood vessels leak and excessive vasodilation causes intravascular volume pooling in the peripheral blood vessels. As blood vessels accumulate in the peripherals, tissue perfusion to vital organs is reduced.

Question 25

causes of anaphylactic shocks

Answer 25

allergic reactions to: food (peanuts) medications insects (bee stings) latex exercise-induced anaphylactic

Question 26

anaphylactic shock transitions

Answer 26

foreign substance (antigen) > systemic antigen-antibody reaction (IgE) > mast cells release potent vasoactive substance (histamine/bradykinin) > activates inflammatory cytokines > causing Vasodilation and capillary permeability.

Question 27

S&S of anaphylactic shock

Answer 27

HR- tachy pulse- rapid but weak pulse CO- decreased due to capillary permeability where fluid is leaving the intravascular spaces BP- hypotension CVP- low SVR- vasodilation O2 sat- low Skin and Temp- generalised flushing RR- increased and laboured due to bronchoconstriction (narrowed airway) resulting in SOB, wheezing, coughing and inability to speak cardiac dysrhythmias or arrest N&V itching, rashes, hives feeling of impending doom

Question 28

Nursing treatment or intervention to anaphylactic shock

Answer 28

*remove the allergen EPIPEN (adrenaline) - to cause vasoconstriction and bronchodilation high flow oxygen antihistamines fluids strict monitoring as anaphylaxis may recur after treatment

Question 29

stages of shock

Answer 29

1. Compensatory- mechanism that initiates restoring homeostasis and blood flow to vital organs *neural - baroreceptors and chemoreceptors in the carotid sinus and aortic arch detects decreased BP and signals vasomotor in the medulla oblongata to increase HR and SVR *hormonal- SNS increases the release of catecholamines (adrenaline) to increase HR and CO. The coronary arteries will dilate to increase blood flow to the heart. RR will also rise to increase gas exchange and O2 levels in the blood. RAAS is also activated as BP decreases. *chemical - hyperventilation occurs since blood flow to the lungs is decreased (detected by chemoreceptors in aorta and carotids) causing a decreased in CO2 levels affecting blood circulation (O2) in the brain therefore causing confusion and restlessness. 2. Progressive- compensatory responses fail to restore adequate BP and tissue perfusion. *cells switch from aerobic to anaerobic metabolism due to absence of O2 leading to build up of lactic acid progressing to metabolic acidosis 3. Irreversible - progressive inadequate tissue perfusion and low BP and HR can lead to multiple organ failure since the body can no longer respond to any form of treatment. Death arise within hours.

Question 30

What is neurogenic shock?

Answer 30

caused by dysfunction or imbalance between sympathetic (causes constriction of the smooth muscles) and parasympathetic stimulation. This kind of shock mainly experiences parasympathetic overstimulation causing excessive vasodilation for extended period.

Question 31

Causes of neurogenic shock

Answer 31

spinal cord injury (above T6, cervical) TBI anaesthesia complications (spinal anaesthesia) opioids and sedative overdose autonomic nervous system disorder insulin reaction

Question 32

S&S of neurogenic shock

Answer 32

HR- brady (since SNS is impaired to compensate in increasing HR) BP- hypotension (due to vasodilation) CO- low CVP- low SVR- low (vasodilation) O2 Sat- low Skin and Temp- dry and warm extremities (venous blood pooling) and hypothermia warm extremities but cold body

Question 33

nursing intervention and treatment for neurogenic shock

Answer 33

*depending the cause of the shock spinal cord injury - protect the spine with cervical collar, backboards and log-rolling intubation and mechanical ventilation head elevation IV fluids *watch for clotting risks - administer compression devises and antithrombic agents vasopressors (adrenaline)

Question 34

S&S of poor tissue perfusion

Answer 34

restlessness or confusion hypotension weak peripheral pulses tachycardia rapid, shallow respirations oliguria (<20 ml/h) systemic venous and pulmonary oedema narrowing pulse pressure (difference of SBP and DBP) dysrhythmia cyanosis and mottling (red-purplish marbling of the skin) S3 and S4 heart sounds hyperglycaemia

Question 35

shock in children is similar to adults and contributing factors are mostly caused by

Answer 35

severe dehydration haemorrhage progressive heart failure sepsis

Question 36

in pedia, shock is present when there are sings of poor tissue perfusion regardless of

Answer 36

blood pressure (shock may be present whether bp is high, normal or low)

Question 37

causes of shock in pedia

Answer 37

hypovolaemic - GI losses, renal losses, haemorrhage, third spacing (accumulation of fluid in the interstitial spaces) distributive shock - septic or anaphylactic shock, neurogenic or spinal shock cardiogenic shock - CHD (congenital heart defects), arrhythmia, valvular disease, cardiomyopathy, myocarditis obstructive shock - cardiac tamponade, pulmonary embolus, tension pneumothorax, obstructive congenital heart lesions (aortic stenosis)

Question 38

common S&S of shock in pedia and infants

Answer 38

initial irritability followed by lethargy tachypnoea (fast RR), hyperpnoea (increased respiratory effort such as gruntling and retractions) mottled and pallor skin tachycardia cool skin and prolonged capillary refill weak peripheral pulses metabolic acidosis decreased central venous O2 sat

Question 39

general nursing management of patient in shock

Answer 39

assess V/S using EWS and ABCDE immediate haemodynamic support (to manage poor tissue perfusion) - O2 therapy, ABGs (due to metabolic acidosis), fluid resuscitation (blood if hemorrhagic), aseptic insertion of IDC (to monitor response to therapy) medications to improve cardiac function, CO and restore normal organ perfusion (vasopressors, antiarrhythmics) 12 lead ECG blood tests