Misc/Triage & Emergency Care Flashcards
What is pulses paradoxus?
- Pulse volume appears to decrease during inspiration and become normal during expiration
- Pericardial effusion, tamponade
Bounding pulses indicate what?
Increased SV & decreased peripheral vascular resistance
What is pulsus alternans?
- Alternating small and large volume pulses most commonly observed with LV heart failure
What is normal I:E?
1:2
Increased expiration time may be a sign of______?
Lung pathology or intrathoracic problem
Increased inspiratory time may be a sign up____?
Upper airway pathology
What is strIdor?
hIgh pitched sound produced by turbulent airflow through the upper airway
What is stertor?
A low pitched sound produced lower in the airway
What percentage of neonates will die in the first 12 weeks?
11-34%
What is normal neonate temp?
98-100F
Why is thermoregulation a problem for neonates?
Their lack of insulating fat, and shivering reflex and peripheral vasoconstriction responses are not fully developed for at least one week
(CO/BP) is a constituent of DO2
CO
What are the 3 constituents of stroke volume?
- Preload
- Contractility
- Afterload
What is shock?
- Inadequate tissue perfusion resulting in poor O2 delivery
- Inadequate cellular energy production
- Most commonly occurs secondary to poor tissue perfusion from low or unevenly distributed blood flow that causes a critical decrease in oxygen delivery in relation to oxygen consumption
What is hypoxia?
Inadequate DO2 to meet tissue metabolic demand (VO2) caused by inadequate tissue perfusion, metabolic disturbances, or lack of oxygen supply
Under normal circumstances, VO2 is (dependent/independent) of DO2
Independent
What is critical oxygen delivery?
- In presence of a marked reduction in DO2, the body is unable to maintain a constant VO2, thus VO2 decreases in proportion to DO2 - COD is the level at which this occurs
- Below COD, anaerobic metabolism occurs to ensure adequate energy production which results in production of lactic acid
What are the five causes of hypoxia?
- Hypoxemic hypoxia
- Hypemic hypoxia
- Stagnant hypoxia
- Histiotoxic hypoxia
- Metabolic hypoxia
What is hypoxemic hypoxia?
Inadequate DO2 results from inadequate CaO2 secondary to hypoxemia from decreased PaO2 and SPO2
What is hypemic hypoxia?
- Anemic hypoxia
- Anemia causes a decrease in circulating Hb, thus reducing CaO2, thus decreasing the DO2
What is stagnant hypoxia?
- Circulatory shock
- Caused by low CO and low blood flow
- Low CO = low DO2
What is histiotoxic hypoxia?
Adequate DO2, but tissues are unable to extract and utilize O2 properly (cyanide, CO)
What is metabolic hypoxia?
- Occurs when there is an increased cellular VO2
- O2 may have been transported correctly, but there wasn’t enough to go around
What are the four main types of shock?
- Hypovolemic
- Obstructive
- Distributive
- Cardiogenic
Why is hypovolemic shock?
- Decreased intravascular volume which then decreases venous return and preload, leading to decreased CO
What is distributive shock?
- Inappropriate dilation
- Normal volume of blood is insufficient to fill the compartment, and blood is displaced away from the heart
- Preload, SV, CO are decreased but BV stays the same
- Expansion of the vascular compartment is due to loss of vessel tone
- Two mechanisms to the expansion: a decrease in sympathetic control of vasomotor tone (depressant drugs, hypoglycemia), or presence of vasodilatory mediators (sepsis, anaphylaxis)
What is obstructive shock?
- Results from a physical obstruction in the circulatory system
- Circulating volume may be normal, but because of the obstruction, there is decreased preload returning to the heart
- HWD, pericardial effusion, gastric torsion
How does sepsis cause distributive shock?
In sepsis, there is a release of prostaglandin, which is a mediator that causes vasodilation
How does anaphylaxis cause distributive shock?
In anaphylaxis, histamine is release, which is a vasodilatory mediator
What is cardiogenic shock?
- When forward flow failure causes inadequate tissue perfusion despite adequate intravascular volume
- Inability to eject blood and achieve normal CO
What is RAAS?
A neuroendocrine response that is started following a drop in BP which attempts to immediately re-establish normal BP and preserve perfusion and DO2 to vital structures
What is the pathway of RAAS?
BP drop —> decreased baroreceptor stretch –> kidney releases renin –> angiotensinogen is produced by the liver –> renin cleaves angiotensinogen and creates angiotensin 1 –> ACE is made by the lungs and converts A1 to angiotenin 2
What is angiotensin 2?
- The major bioactive product of RAAS
- Potent vasoconstrictor
- Stimulates secretion of ACTH, aldosterone, and ADH
How does cortisol contribute to RAAS?
- Cortisol is secreted by ACTH
- Cortisol helps induce a catabolic state allowing the body to break down reserves for immediate energy needs stimulates gluconeogenesis and generates glucose form non carbs like lactate, and retains Na & H2O in kidney
How does aldosterone contribute to RAAS?
- Body’s main mineralocorticoid hormone
- Has vasoconstrictive properties
- Further contributes to Na retention which allows for more H2O retentoin, thus improving intravascular volume
How does vasopression contribute to RAAS?
- It increases water permeability within the kidney, which conserves H2O
- Potent vasoconstrictor
What are the 3 stages of hypovolemic shock?
- Compensatory
- Early decompensatory
- Late decompensatory
Why does normo/bradycardia in shock suggest late decompensation?
Tachycardia is an appropriate and expected response to circulatory shock. When arterial BP is threatened by a drop in SV or as a result of vasodilation, there is a baroreceptor mediated increase in sympathetic tone, resulting in a reflex tachycardia
Why is hypothermia seen in shock?
The sympathetic-mediated vasoconstriction that occurs in response to a drop in CO tends to shunt blood from venous capacitance vessels to the central circulation, preserving blood flow to vital organs at the expense of less vital organs
What is the most effective way to improve O2 delivery?
To increase CO by optimizing preload with administration of fluid
After ___ minutes, ___% of the volume of isotonic fluids has shifted from the intravascular to interstitial space
30, 98
Why is hypertonic utilized to improve intravascular fluid?
It is a concentrated Na solution that causes a rapid shift of fluid into the intravascular space because water follows sodium
When TP is <___ or albumin is <___, it may be difficult to maintain intravascular volume with isotonic crystalloids alone
<3.5; <1.5g/dL
O2 delivery is limited when Hct drops below ___%
20%
If hypotension remains in the face of adeuqate cardiac volume, the cause must be either decreased _____, or ____
Decreased cardiac contractility or vasodilation
Does dopamine increased BP in dogs and cats
No