SHOCK - SRS Flashcards
What is normal CO?
4-8 L/min
What is normal cardiac index?
2.6 - 4.2 (L/min)/m2
What is normal stroke volume?
50-100 ml/beat
What is normal SVR?
700-1600 dynes*s/cm5
What is the normal pulmonary vascular resistance?
30-130 dynes*s/cm5
What is the normal left ventricular stroke work?
60 - 80 g-m/beat
What is the normal right ventricular stroke work?
10-15 g-m/beat
At what % of nl blood volume are people considered to be in mild, moderate and sever hypovolemic shock?
Mild: <20% blood volume loss
Moderate: 20-40% blood volume loss
Severe: >40% blood volume loss
What are five presentations associated with mild hypovolemic shock?
- Cool extremities
- increased capillary refill time
- diaphoresis
- collapsed veins
- anxiety
What are 9 clinical presentation items associated with moderate hypovolemic shock?
(hint: 5 are the same as in mild)
Same as in mild…
- Cool extremities
- increased capillary refill time
- diaphoresis
- collapsed veins
- anxiety
NEW FOR MODERATE
- Tachycardia
- tachypnea
- oliguria
- postural changes
Severe hypovolemic shock has the same presentations as mild and moderate PLUS what other four things?
And for the hell of it, what are the other 9 items that it has in common with mild and moderate hypovolemic shock?
NEW for severe…
- hemodynamic instability
- marked tachycardia
- hypotension
- mental status deterioration
Same as in mild…
- Cool extremities
- increased capillary refill time
- diaphoresis
- collapsed veins
- anxiety
Same as in MODERATE
- Tachycardia
- tachypnea
- oliguria
- postural changes
Again, because it sounded like a test item, what is the normal SVR?
700-1600
What are the ATLS classifications of shock by blood loss?
I: up to 750 ml (~15%)
II: 750-1500 ml (15-30%)
III: 1500-2000 ml (30-40%)
IV: >2000 ml (>40%)
What is the urine output in class IV haemorrhagic shock?
Negligible
What are the CNS/mental status changes for class I-IV hemorrhagic shock?
I: SLightly anxious
II: Mildly anxious
III: anxious and confused
IV: Confused and lethargic
What receptors detect hypotension and hypovolemia? 4
- •High-pressure baroreceptors
- •Low-pressure baroreceptors
- •Renal Juxtaglomerular apparatus
- •Central and peripheral chemoreceptors
What is the autonomic efferent response to hypotension?
•↑ sympathetic
↓ parasympathetic
What are the components of the effector response to hypotension?
Specifically for the heart, vasculature, adrenals, kidney and skin.
- ↑ HR (nodal cells)
- ↑ contractility (↑ [Ca2+]i in contractile myocytes)
- ↑ TPR (VSMC contraction; veno- and vasoconstriction)
–Attempt re-establish MAP
- ↑ Circulating epinephrine (Adrenal medulla)
- ↑ Renin (Granular cells in the renal JXG apparatus)
- ↑ Sweat gland activity (Sympathetic cholinergic stimulation; clammy extremities)
What effect will hypotension/hypovolemia have on humoral regulation of vascular tone?
↑ ADH/AVP –> ↑ vasoconstriction
↑ ANG II by activation of RAAS –> ↑ vasoconstriction
By what two ways is renin upregulated in response to hypotension/hypovolemia?
(1) Sympathetic stimulation of juxtaglomerular granular cells –> renin
(2) Renal vasoconstriction –> ↓ renal pressure –> ↑ renin
What are three ways that the body tries to correct lost blood volume?
- Renal fluid conservation
- Stimulation of thirst –> water intake
- Net capillary reabsorption (Starling’s forces)
•“Transcapillary refill”
Hypotension/hypovolemia leads to ↓ renal blood flow which leads to ↓ filtration rate & ↓ Na+ and H2O excretion. Which leads to the dark side. How does a Jedi (and all the rest of us) promote renal retention of Na+ and H20?
- ↑ Sympathetic activity
- ↑ ANG II = ↑ Aldosterone, ↑ ADH/AVP secretion, ↑ Thirst stimulation
- ↑ Aldosterone = ↑ Na+ reabsorption
- ↑ Anti-diuretic hormone/Arginine Vasopressin = ↑ H2O reabsorption