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
When is norepinephrine indicated?
In cases of distributive shock to increase vasoconstriction
How does norepinephrine lower HR?
Baroreceptor reflex when BP increases
When is phenylephrine indicated?
Indicated for hypotension when beta adrenergic agonist effects are not desirable
How is vasopressin dosed?
- Units or milliunits
- 1 millunit = 0.01 units
When is vasopressin indicated for hypotension?
- When vasoconstriction is needed independent of adrenergic stimulation
At low doses of epinephrine, ____ effects predominate
- beta adrenergic
- Improves CO and cardiac contractility
At high doses of epinephrine, ____effects predominant
- Alpha 1 adrenergic
- Improves BP by vasoconstriction
What should intratracheal oxygen rates not exceed, and why?
- 0.5L/min
- Higher rates cause the tube the oscillate and irritate the trachea or can lead to overdistension of lung
Opioids are (effective/poorly effective) in chronic pain and neuropathic pain states
Poorly effective
What medications are not recommended for shock states?
Abx, steroids, NSAIDs
What is CVP?
- The BP in the intrathoracic anterior vena cava compared with a column of H2O in a manometer
Jugular venous PO2 samples less than ____mmHg or greater than ___mmHg may be caused by decreased O2 delivery to the tissues and reduced O2 uptake by the tissues, respectively
30; 60
What are the two forms of lactate?
- L = predominant biological and functioning form
- D = small role, of limited concern
What organs metabolize lactate?
Liver, kidney, myocardium
What is Type A hyperlactatemia?
- Seen in states of hypoxia and anaerobic metabolism
- Hypoperfusion, anemia, severe hypoxemia, CO toxicity
- Patient struggling, seizures/tremors
What is Type B hyperlactatemia?
- NOT related to anaerobic metabolism and hypoxia
- Systemic disease, drugs, or toxins
- B1 = DM, neoplasia, hepatic failure, sepsis/SIRS
- B2 = Corticosteroids, glucose, xylitol, catecholamines
- B3 = inborn congenital disease
Normalization of lactate within ____ hours is an important predictor of M&M
24 hours
What is the goal of all compensatory mechanisms in shock?
To maintain CO
If adequate fluid resuscitation and pressors have been unsuccessful in improving BP, what class of medications can be tried?
Corticosteroids at physiologic doses
Which IVC materials are less thrombogenic?
Silicone and polyurethane
Which IVC materials are most reactive?
polyvinyl chloride, polyprophylene, and polyethylene
Cells continue to metabolize glucose at a rate of _____ if serum/plasma is not removed from RBC in a blood tube
5-10% per hour
What is the normal USG for dogs and cats?
1.030-1.035
Will the USG be increased or decreased in oliguria?
Increased
Will the USG be increased or decreased in polyuria?
Decreased
The (number/size) of colloid particles determines the COP
number
The (number/size) of colloid particles determines how long it is retained in the IVS
size
Short and shallow breathing may indicate___?
A restrictive breathing pattern, often pleural space disease
Arterial waveform: What is the systolic upstroke called and what does it represent?
Anacrotic limb, the ventricular ejection of blood into systemic arterial system
Arterial waveform: What is the at the top of the waveform?
The peak systolic BP - the maximum pressure generated during ventricular ejection
Arterial waveform: What is the dicrotic notch?
Aortic valve closure
What is the lowest point of the arterial waveform?
Diastolic blood pressure
A dicrotic notch that approaches the peak systolic pressure may indicate _____?
Vasoconstriction
A dicrotic notch that approaches the diastolic pressure may indicate _____?
Vasodilation
What is an overdampened arterial waveform?
- Dull and rounded appearance
- SBP artificially low, DBP artificially high
- Air bubbles or clot in tubing
What is an underdampened arterial waveform?
- Tall, sharp appearance
- SBP artificially high and DBP artificially low
Width of the BP cuff should be _____% of the circumference of the limb
40-60%
What is the Beer-Lambert law and what is it applied to?
- It associates the intensity of light transmitted through a solution to the solution’s concentration
- SPO2
What is CO2?
The major byproduct of tissue metabolism
How is ETCO2 used to assess CO?
Because CO and pulmonary perfusion are required for gas exchange, ETCO2 serves as a reliable, non invasive modality to assess CO
What can cause rebreathing of CO2?
- Inadequate CO2 scavenging - exhausted granules
- Inadequate fresh gas flow in NRB circuit
- Malfunciton of anesthetic machine
- Excessive dead space
Will patients have their oxygenation affected by elevated CO2 if they are breathing 100%?
No
Will patients have their oxygenation affected by elevated CO2 if they are breathing room air?
Yes - elevated CO2 can easily cause hypoxemia because CO2 displaces O2 from lungs
Why is an abrupt drop in CO2 one of the earliest signs of cardiovascular collapse?
The delivery of CO2 to the lungs requires blood flow
Why can there be an inaccurate capnogrpah reading in panting/tachypnic patients?
- An adequate duration flat alveolar plateau is needed for the capnogram to accurately generate an ETCO2 level
- The plateau occurs after the breath is exhaled, but before the next breath is taken
What can low CVP (<0 cmH2O) indicate?
It may indicate inadequate intravascular filling
What can high CVP (>10 cmH2O) indicate?
It may indicate intravascular volume overload, right sided cardiac dysfunction, or increaes in intrathoracic pressure (pleural effusions, pneumo, PPV)
What does a Swan Ganz catheter measure?
It is placed through the jugular into the right heart and allows for direct measurement of pressures in RA, RV, pulmonary artery, and filling pressure of LA. It is needed for mixed venous O2 saturation monitoring (SvO2)
What is pulmonary capillary wedge pressure now called?
Pulmonary artery occlusive pressure
Why is acidosis detrimental to the body?
Significant acidosis causes dysfunction in all enzyme driven functions in the body
Why is hypothermia detrimental to the body?
It decreases metabolic rate, causes a decrease in SA node automatacity, an increase in ventricular ability, a decrease in enzymatic reactions, and in crease in membrane permeability, and a failure of ion pumps
Why should IM analgesia be given in the epaxial muscles?
Blood flow to this muscle bed is more consistent even in the face of alterations in tissue perfusion
What are two methods to reduce the sting of local anesthetic?
- Warm to room temp
- Add 10% NaHCO3
What should not be done when intubating a TVI patient?
Do not lift the head - decrease in blood flow may lead to cardiac arrest
What side down should flail chest patients be on?
Flail side down
What is a flail chest?
A segment, free floating, or 3 or more adjacent ribs that moves paradoxically with each breath
What is compartment syndrome?
Occurs when pressures rise and circulation to area is obstructed, rapidly leading to tissue necrosis
What does a “shark fin” appearance on capnograph indicate?
It suggests an airway or breathing circuit obstruction (kinked ETT, bronchospasm, airway mucus plug)
What does an elevated capnograph baseline indicate?
CO2 rebreathing and inspired CO2
What is canine distemper?
- Morbillivirus
- Transmission respiratory secretions
- Virus has the ability to persist in CNS
- Enamel hypoplasia seen in adult dogs is evidence of prior CDV infection
What is FeLV?
- Feline leukemia virus infection
- Retrovirus that causes immunosuppression and lymphocytic neoplasia
- Tumor induction occurs when DNR provirus integrates into cat chromosomal DNA in specific oncogene regions
- Can cause anemia, degenerative myelopathy, neuropathies
- Immunosuppression with resulting seondary infections or neoplasia
- More common in outdoor cats
What is FIP?
- Caused by virulent feline coronavirus
- FCoV replication occurs rapidly within intestinal epithelium
- Multisystem disease is an immune mediated disease leading to widespread vasculitis
- Effusive disease is a result of vasculitis, vessel destruction, and formation of pyrogranulomata
- Fecal to oral transmission
What breed of cat may be genetically predisposed to FIP?
Persians
What does FIP abdominal effusion look like?
- Viscous, yellow/straw
- May form clots or foam
- Hypocellular fluid
- TP >3.5
Neuro signs occur in what % of cats with non effusive FIP?
25-33%
What is FIV?
- A retrovirus infection which causes immune suppression in domestic cats
- Same genus as HIV
- Male cats are more likely to develop than females
- Horizontal transmission via saliva or blood, usually by biting
Most cardiac murmurs in dogs and cats are what type?
Systolic
Continuous murmurs occur through ___ & ____
Systole and diastole
What type of defibrillation is more successful in terminating vfib?
Biphasic
Where is thoracocentesis performed?
- 7th-9th intercostal space
- Insertion site should be at the cranial aspect of the desired rib
How does the four quadrant passive drain technique work?
It works through hydrostatic pressure and passive drainage
