Card Set Information
VTHT Anesthesia Surgery
review of the respiratory system
This is the total process whereby oxygen is supplied to and used by body cells and carbon dioxide is eliminated by means of gradients (high to low)
This is the movement of gas in and out of the alveoli
This is the maximum amount of oxygen with which each gram of hemoglobin can be combined
The oxidation of this molecule produces the end product CO2
What compound is formed by carbon dioxide in the presence of carbonic anhydrase and water?
This phase of respiration is the active process that requires energy
The muscles involved in inspiration are:
External intercostal muscles
This phase of respiration is the passive process resulting from the natural recoil of the lung and the chest wall
The muscles involved when expiration needs to be forced are:
Internal intercostal muscles
Three areas of pulmonary ventilation
Muscles - cause lung expansion and contraction
Movement of air-pressure changes cause a complete collapse of the lung and expulsion of air
Pleural Pressure - negative pressure surrounding the lung create a suction to hold lungs open
Anesthetics suppress primarily 2 bodily functions
1. heart rate
This refers to normal quiet breathing
This is labored breathing
This refers to fast and/or deep breathing
This refers to rapid shallow panting
This is the total but usually not permanent cessation of breathing
This refers to a slow and/or shallow breathing
This refers to long, gasping inspirations with several subsequent ineffective exhalations often seen with cyclohexylamine administration
This refers to a sequence of gasps, apnea, and several deep gasps
This is an increase in rate and depth of respiration then become slower, followed by a brief period of apnea
This refers to regular deep respirations without pause
This abbreviation represents the concentration of oxygen attached to hemoglobin
This abbreviation represents the concentration of oxygen free in the plasma
This abbreviation represents the concentration of carbon dioxide free in the plasma
This abbreviation represents adequate oxygen delivery
This abbreviation represents reduced oxygen consumption usually only measure in humans and thoroughbreds
Which is larger: the amount of oxygen dissolved in plasma or bound to hemoglobin?
Oxygen bound to hemoglobin
This is the volume of air inspired or expired in one respiration and is often very associated with the patient's weight.
This is the volume of air that can be inspired over and above normal Tidal Volume (TV)
Inspiratory Reserve Volume (IRV)
This is the volume of air that can be expired by forceful expiration after normal tidal expiration
Expiratory Reserve Volume (ERV)
This is the volume of air remaining in the lungs after the most forceful expiration
Residual Volume (RV)
True or False: there is no difference between a ventilator and a respirator.
This is used to describe the amount of gas moved per minute
Minute Volume (MV)
Mammalian normal Tidal Volume
Minute Volume =
MV = Tidal Volume(TV) x Respiratory Rate (RR)
Normally if the respiratory rate increases, what happens to the tidal volume?
What portion of ventilation is important for and contributes to gas exchange?
This refers to the area ventilated by tidal volume where there is little or no diffusion of O2 and CO2
Dead space ventilation
What areas comprise the dead space in ventilation?
What is the percentage of dead space ventilation in normal tidal and minute volumes?
This is when you breathe for the animal via respiratory bag, ambu bag and blowing into the tracheal tube
Positive Pressure Ventilation (PPV)
What level of hypercarbia/hypercapnia (CO2) requires PPV?
CO2 > 60 mmHg
What level of desaturation (SpO2) in spite of oxygen therapy requires PPV?
What level of hypoxemia (PO2) requires PPV?
PO2 < 100 mmHg
Other cases requiring PPV
1. Open chest surgery - eg diaphragmatic hernia
2. Neuromuscular disease - eg tick paralysis
3. Chest wall trauma that results in an open wound
4. Abdominal enlargements - eg gastric torsion/dilation complex
5. Pulmonary parenchymal disease - pneumonia
What is the RQ?
uotient is found by the O2/CO2 in respiratory exchanges (results should always be a decimal)
This refers to the amount of air that can be breathed beginning at the normal expiratory level and distending the lungs to the maximum amount
Inspiratory Capacity (IC)
This is the amount of air remaining in the lungs at the end of a normal expiration
Functional Residual Capacity (FRC)
FRC = ERV + RV
This is the maximum amount of air that can expelled from the lungs after first filling the lungs to their maximum extent and then expiring to the maximum extent
Vital Capacity (VC)
VC = IRV + TV + ERV
This is the maximum volume the lungs can be expanded with the greatest possible inspiratory effort
Total Lung Capacity (TLC)
TLC = VC + RV
What are the secondary functions of respiration?
Phonation - Voice production
Body Temperature regulation
Olfaction - Sense of smell
These structures may contribute to the resonance and characteristics to phonation
This is caused by two connective tissue bands stretching across the larynx and vibrating as air passes over them
Phonation or voice production
How does breathing provide body temperature control?
A network of superficial blood vessels under the nasal epithelium warm air as it passes through which prevents chilling of the blood in the lungs
This is the unit used to express the relative acidity or alkalinity representing the negative logarithm of the hydrogen ion concentration
Neutral blood pH
Acceptable range for blood pH
7.35 - 7.45
This system contributes to the process of acid-base control by altering the CO2 content of the blood by adjusting the amount and rate of CO2 coming in and out
A higher concentration of CO2 makes the blood:
A too low concentration of CO2 makes the blood:
These causes substances like lactic acid and CO2 to constantly accumulate in the blood
breakdown of food and glucose oxidation
Name and describe the methods that the body uses to maintain neutral blood pH
1. sodium bicarbonate release from the pancreas - neutralizes acids
2. normal respiration - brings in more O2 (RQ 700:1)
3. Kidneys retain Na+ and excrete H- and Cl-
Condition that can result in metabolic acidosis
diarrhea - loss of sodium bicarbonate
ketosis - starvation
severe infectious disease - septicemia
renal insufficiencies - loss of Na+/retention of H- & Cl-
administration of acid drugs (abx)
causes the retention of CO2 in the blood and results in
This refers to excess CO2 in the blood
Hypercapnia or hypercarbia
Conditions that can result in metabolic alkalosis
vomiting - loss of Cl- ions/retention of Na+ ions
causes an increase in O2 in the blood and results in
This refers to a decrease of CO2 in the blood
Hypocarbia or hypocapnia
Animals are considered functionally
This is term for the sense of smell
This is the exchange of oxygen and carbon dioxide between the blood in the capillaries in the body and the cells/tissues of the the body
This device is used to measure volumes of air in the lungs during the respiratory process and tests lung performance in thoroughbreds and humans
This is the basic force behind gas exchange as the molecules move from an area of higher concentration(high pressure) to an are of lower concentration(low pressure)
Atmospheric air consists of:
Nitrogen ~ 79%
Oxygen ~ 20%
Carbon dioxide ~ 0.03%
List the layers gas travels through from the alveoli to the RBC:
1. Phospholipid Surfactant lining of the alveoli
2. Alveoli epithelium
3. Capillary endothelium with intercellular clefts
5. Erythrocyte membrane
This is the approximate distance from the surfactant lining of the alveoli to the rbc membrane
less than 1 micron
At complete saturation each hemoglobin molecule is combined with how many oxygen molecules?
4 O2 molecules
This refers to the percentage of oxygen consumed during normal activity
Utilization Coefficient = 25%
Strenuous activity might increase the utilization coefficient to what percentage?
These two things directly influence O2 and CO2 concentrations
circulation - cardiac control
respiration - respiratory control
Control by circulation and respiration is done by what two things?
glossalpharyngeal and vagus nerves
regulation of O2 and CO2
Another name for the cardioinhibitory center
central respiratory center
Central respiratory centers are located where?
What are the central respiratory centers?
These detect concentrations of O2 and CO2 at the aortic arch and carotid sinus
These measure blood pressures at the aortic arch and carotid sinus
Peripheral Pressoreceptors (Baroreceptors)
With what 3 areas are the central respiratory centers in direct nervous contact?
Bifurcation of the trachea in the lungs
generally respond to O2 and CO2 concentrations to
generally respond to blood pressures to
This is the bifurcation of the carotid artery to form the internal carotid arteries
Respiration and Circulation receptors and connections:
1. Impulses from Aortic Arch > Vasomotor and Cardioinhibitory centers via Vagus nerve
2. Impulses from Carotid Sinus > Vasomotor and Cardioinhibitory centers via Glossapharyngeal nerve
3. Impulses from the Cardioinhibitory center > Heart and Lungs via Vagus nerve
Circulation has one further receptor/connection relationship.
Impulses from the Vasomotor center > blood vessels via Sympathetic neurons (& reduction of vagus nerve stimulation
Chemoreceptors are stimulated by:
lack of O2 < 70mmHg
increase in CO2 - this is how analeptics function
Hering - Breuer Inflation Reflex
1. A volume exceeding tidal volume activates the stretch receptors in the bronchi.
2. An impulse via the vagus nerve goes to the Central respiratory center (cardioinhibitory center) to terminate inflation
Hering-Breuer Deflation Reflex
1. Usually associated with an accidental deflation of a lung - activates stretch receptors in the alveoli.
2. An impulse via the vagus nerve goes to the Central respiratory center (cardioinhibitory center) to accelerate respiration
Name techniques used to manually stimulate the Hering-Breuer reflexes:
1. slight manual compression of the chest
2. slapping the chest
3. "run the ribs"
Cough sequence of events
1. Irritation to respiratory passage sends impulse via vagus nerve to medulla.
2. A liter of air is inspired
3. The epiglottis and vocal folds close and shut tightly to trap the air in the lungs
4. The abdominal muscles contract and push against the diaphragm
5. the vocal folds and epiglottis open widely so the air under pressure explodes outward
Similar to the cough reflex with two important distinctions:
1. the impulse travels from the nasal passages to the medulla via the trigeminal nerve
2. the uvula or soft palate is depress forcing the large amount of air out through the nose to help clear the irritant
This refers to a slow, deep breath taking through a wide-open mouth
What two factors may stimulate a yawn?
1. slight decrease in O2 level of the blood
2. boredom, drowsiness, or fatigue
This is a slightly deeper than normal breath not normally associated with a wide-open mouth
This is a spasmodic contraction of the diaphragm accompanied by a sudden closure of the glottis and epiglottis
What 3 serious conditions can result in hiccuping?
1. nerve irritation
3. CNS damage
This means the state of decreased O2 availability
Name the immediate responses to hypoxia:
1. Dilation of the coronary and cerebral blood vessels - unconsciousness
2. Constriction of peripheral vessels
3. Respiratory increase
4. Elevation of pulse rate and blood pressure
5. Increase in cardiac output
6. Vomiting and Nausea
7. Reduced RBC
8. Dilated pupils - terminal sign of death
Name the chronic responses to hypoxia:
1. No real noted change to coronary or cerebral vessels
2. Fall in pulse rate and blood pressure
3. Slow decrease in cardiac output
Accumulation of waste (CO2) > Capillaries dilate > increased capillary permeability > loss of blood plasma into tissues > Hemoconcentration > Reduced blood flow > Accumulation of waste (CO2)
This is a condition where the normal negative pressure of the pleural cavity is interrupted and air is allowed inside
The two types of pneumothorax are:
1. Open - communication between the inside of the thorax and the outside environment - penetrating wound
2. Closed - no communication between the inside of the thorax and the outside environment - crushed lung
Another name for a closed pneumothorax
Paradoxical Respiration Movement
1. Air into the collapsed lung first
2. Then into the intact lung
collapsed lung becomes smaller upon inspiration
3. Air expired first into the collapsed lung
4. Then out into the environment
collapsed lung becomes larger upon exhalation
This is the condition is caused pus from foreign bodies or puncture wounds through the chest wall.
This is the most common foreign body in a pyothorax
This is the condition where chyle accumulates in the thorax usually from a thorax duct rupture from trauma
This is triglyceride-rich lymphatic fluid from the intestinal lymphatics that usually empties into the venous system at the azygos vein
This condition results from mediastinal lymphoma
Resuscitation steps (ABCD)
1. Make sure the animal is on its right side
irway must be immediately established with a endotracheal tube
reathing is assisted with Positive Pressure Ventilation (PPV) @ 12 breaths per minute & Tidal volume of 5-10mL/#
ardiac compressions at 60/min. >30 # use both hands, <30 # use thumb and fingers
rugs - initiate 1 minute after starting compression via IV
Where is Kussmal respirations seen most?
This is the most common hernia
This is the second most common hernia
This is a hernia at the intersection of the diaphragm and the esophagus
Name the ventral hernias
Which respiratory volume cannot be controlled?
These factors can cause RQ variance.
These factors can affect hemoglobin saturation
Conditions that often cause in chronic hypoxia
Chronic Lung Infection
Diabetes Mellitus and Insipidis