CR3 EOYS3 Flashcards
Explain three examples that could cause obstructive shock xx [2]
PE
Tension pneuomothorax air gets trapped in pleural space: compresses against vena cava and heart: stops blood flow into right side of heart: reduced preload: reduced CO
Cardiac tamponade :accumulation of pericardial fluid: causes increas in intrapericardial pressure which reduceds cardiac filling
Explain 3 examples of distributive shock x
Sepsis: dysregulated host response to infection where bacteria in blood release chemicals causing uncontrolled hypotension
Anaphylactic shock: allergic response to antigen: IgE mediated mass degranulation releasing histamines: vasodilation and capillary leaking
Neurogenic shock: loss of sympathetic tone and thus unopposed parasympathetic response driven by the vagus nerve. Consequently, patients suffer from instability in blood pressure,
What is cardiogenic shock?
Name 4 causes of cardiogenic shock xx [4]
Failure of the heart to pump blood
Occurs as a result of ventricular dysfunction (esp. LV)
Causes:
* Acute myocardial infarction leading to ventricular dysfunction
* Arrhythmias
* Valvular rupture
* Decompensated heart failure
Explain 4 causes of hypovolaemic shock xx
- Haemorrhage
- GI losses: severe diarrhoea and vomiting
- Surgery: exposure of internal structures to heat
- Burns: fluid shift into extravasuclar space due to inflam response
Explain the compensatory mechanisms for haemorrhagic shock [3]
Baroreceptors detect drop in arterial pressure
Activates sympathetic stimulation:
- Constriction of small arterioles increasing total peripheral resistance thereby maintaining BP
- Veins and venous reservoirs constrict, maintaining venous return
- Increased heart rate and contractility to maintain cardiac output
CNS ischaemia results in increased noradrenaline and adrenaline secretion from adrenal medulla
How does RAAS system work to compensate shock? [3]
- Water retention and salt reabsorption
- Vasomotor centre in the medulla signals to the hypothalamus to release vasopressin (ADH)
- Urine flow and sodium excretion decrease
Name 3 long term compensatory mechanisms of shock [3]
- There is (by an unknown mechanism) stimulation of albumin and other plasma protein synthesis in the liver.
- Increased fluid absorption from GI tract
- Fibroblasts surrounding the kidney tubules are sensitive to hypoxia and release increased amounts of erythropoietin: Red cell production
CO = [] X []?
BP = [] x []?
CO = HR X SV
BP = CO x Systemic vascular resistance
Vasodilation is mediated by the activation of which two compounds? [1]
Explain their basic mechanism [1]
Nitric oxide and prostacyclin [1]
MoA: Through cGMP and cAMP respectively, secondary messengers cause decrease in calcium and smooth muscle relaxation
Vasoconstriction is predominately activated by which molecule on which receptors? [2]
Name two alternative compounds that can cause vasoconstriction [2]
Vasoconstriction is predominately activated by which molecule on which receptors? [2]
Noradrenaline on alpha 2 recptors
Name two alternative compounds that can cause vasoconstriction [2]
Angiotensin
Vasopressin
What are the overall physiological consequences of shock ? [3]
- Increased afterload
- Reduced systemic vascular resistance (Failure to maintain peripheral vasoconstriction)
-
Decreased CO
i) reduced preload
ii) reduced contactility
Name and describe the 4 stages of shock
What are the signs of shock?
- Pulse is weak and rapid
- Pulse pressure reduced - mean arterial pressure (MAP) may be maintained - NOTE; ARTERIAL BP is NOT A GOOD INDICATOR OF SHOCK since it will be maintained until a very large amount of blood loss
- Reduced urine output
- Reduced pH
- Confusion, weakness, collapse and coma
Describe the 4 classes of haemorrhagic shock
x
Explain which of HR or BP falls first in major haemorrhage stroke :)
Cardiac output can accommodate c. 10% blood loss before change in CO
Between 10-20% fall in blood loss, arterial pressure compensates by vasoconstriction
SO you see a raise in HR to compensate fall in SV BEFORE you see a fall in BP
Whats the A-E of shock management?
Airway: probs ok unless they have analphylaxis
Breathing: usually ok, may have compensatory increase in RR to compensate hypoxia in tissues. OR might have tension pneumothorax. Later stages: hypoxic
Circulation: give IV access: increase fluids to increase BP
Disability: Low: cant respond bc of lack of 02
Exposure: look at skin – rash / burns / pale
What is chylothorax? [1]
Why may it occur? [1]
Chylothorax: leakage of lymph into the pleural cavities
Can cccur due thoracic duct damage
What is the path of the testes lymphatic drainage?
What is the path of the scrotum lymphatic drainage?
What is the path of the ovaries lympahtic drainage?
What is the path of the testes lymphatic drainage?
Testes –> preaortic aorta
What is the path of the scrotum lymphatic drainage?
Scrotum –> superficical inguinal nodes
What is the path of the ovaries lympahtic drainage?
Ovaries –> preaortic aorta
Lymph from the internal and external iliac nodes drains into the [] nodes and then the [] nodes.
Lymph from the GI tract drains into the [] lymph nodes ([], [] and [] nodes)
Intestinal + right and left lumbar trunks drain to []
Lymph from the internal and external iliac nodes drains into the common iliac nodes and then the lumbar nodes.
Lymph from the GI tract drains into the pre-aortic lymph nodes (celiac, superior mesenteric and inferior mesenteric nodes)
Intestinal + right and left lumbar trunks drain to cisterna chyli (beginning of thoracic duct)
What is waldeyers ring? [4]
Waldeyer’s ring consists of four tonsillar structures:
- pharyngeal
- tubal
- palatine
- lingual
As well as small collections of lymphatic tissue disbursed throughout the mucosal lining of the pharynx (mucosa-associated lymphoid tissue, MALT).
What are the axillary lymph nodes? [3]
Where do they drain lymph from? [3]
Ddescribe their path to to L / R venous angle [2]
Humeral lymph nodes drain from upper limb
Pectoral lymph nodes drain from anterior chest wall (majority drains into here)
Subscapular lymph nodes drain from posterior chest wall (rotator cuffs etc)
Together: go to central –> apical –> supraclavicular –> left / right venous angle
Describe the path of deep drainage of the thorax lymphatics
Sub pleural plexus –> interlobal lymph vessels –> interpulmnarry lobes –> inferior trachea bronchiol nodes –> superior trachea bronchiole lobes –> bronchomediastinal trunks –> L / R venous angle
The thoracic duct enters the thorax through the [] and travels in the [] mediastinum between the [] and the [] vein.
The thoracic duct enters the thorax through the aortic hiatus and travels in the posterior mediastinum between the aorta and the azygos vein.
Central lines (also known as a central venous catheter) are catheters that can be place in a large vein to give medication or fluids or to collect blood for medical tests.
Given your anatomical knowledge which veins do you think are used for central lines?
Acceptable responses: Internal jugular vein, Internal jugular, Subclavian, Subclavian vein, Femoral, Femoral vein
Label 1-3
1: LCA
2: LAD
3: Left circumflex
Which valves close during S1?
Which valves close during S2?
Where do each of the following correspond to on an ECG?
S1: closure of mitral and tricuspid valves: QRS
S2: close of aortic and pulmonary valves: After T wave
At what time does ductus arteriosus normally close?
Seconds after birth
1-3 days after birth
2 weeks after birth
6 months after birth
At what time does ductus arteriosus normally close?
Seconds after birth
1-3 days after birth
2 weeks after birth
6 months after birth
Label the vert. layers of A-D
The laryngeal prominence occurs at which vertebral level
C3
C4
C5
C6
C7
The laryngeal prominence occurs at which vertebral level
C3
C4
C5
C6
C7
The carotid bifurication occurs at which vert. level?
C3
C4
C5
C6
The carotid bifurication occurs at which vert. level?
C3
C4 : carotid pulse can be palpated either side of thyroid cartilage
C5
C6
The cricoid cartilage occurs at which vert. level?
C3
C4
C5
C6
The cricoid cartilage occurs at which vert. level?
C3
C4
C5
C6
The thyroid gland occurs at which vert. level?
C3
C4
C5
C6
The thyroid gland occurs at which vert. level?
C3
C4
C5
C6: overlies cricoid cartilage
Thyroid gland overlies which laryngeal cartilage?
Thyroid cartilage
Cricoid cartilage
Epiglottis
Artyenoid cartilages
Thyroid gland overlies which laryngeal cartilage?
Thyroid cartilage
Cricoid cartilage
Epiglottis
Artyenoid cartilages
What are the 3 components to a definitive airway? [3]
1) Tube placed within the trachea with cuff inflated BELOW vocal cords (most important to know)
2) Tube connected to oxygen enriched assisted ventilation
3) Airway secured in place with appropriate stabilizing method
How can burns of neck / face cause closure of airways? [1]
Direct damage to tissues:
- can cause secondary oedema and swelling of soft tissues
- can be dealyed occlusion of the airway
How can trauma to face/neck cause closure of airway?
Direct obstruction
- Laryngotracheal fractures
Secondary obstruction
- Displacement of local structures
- Loose teeth, bone fragments etc.
- Post-traumatic complications:
eg. haematoma/swelling
