Card Set Information
Sheri's respiratory lecture
What is ventilation?
movement of air in and out of airways
What is perfusion?
getting the air that is in the alveoli to diffuse by Henry's law
ways perfusion can be prevented
blood clots, decreased blood flow, decreased blood volume
nose, paranasal sinuses, pharynx, tonsils, adenoids, larynx, trachea
lungs - pleura, mediastinum, lobes, bronchi, bronchioles, alveoli
What is shunting?
perfusion is better than ventilations
low ventilation - perfusion ratio
perfusion exceeds ventilation
blood bypasses the alveoli without gas exchange occuring
causes of shunting
What is dead space?
ventilation is better than perfusion
high ventilation - perfusion ratio
ventilation exceeds perfusion
alveoli do not have an adequate blood supply for gas exchange to occur
causes of dead space
What is a silent unit?
no ventilation or perfusion
absence of both ventilation and perfusion or with limited ventilation and perfusion
causes of a silent unit
severe acute respiratory distress syndrome
what are some elderly considerations when discussing ventilation and perfusion?
airways of alveoli thicken and become less compliant
airways have more dead space
surface area available for exchange of oxygen and carbon dioxide decreases
alveoli begin to loose elasticity around age 50
decrease in vital capacity occurs w/ loss of chest wall mobility --> restricts tidal flow of air
decreased diffusion capacity for O2 w/ increasing age --> produces lower O2 levels in arterial circulation
decreased ability to rapidly move air in and out of lungs
normal ventilation:perfusion ratio
varies in different areas of lungs
things that may alter perfusion
change in pulmonary artery pressure
change in alveolar pressure
change in gravity
things that may alter ventilation
local changes in compliance
changes in gravity
what is compliance?
measure of the force required to expand or inflate the lungs
4 possible states of gas exchange in lungs
normal (V/Q) ratio
shunting (low V/Q ratio)
dead space (high V/Q ratio)
silent unit (no ventilation or perfusion)
What is the main cause of hypoxia after thoracic or abd surgery and most types of respiratory failure?
What is the purpose of a pulse oximetry?
it's a noninvasive way to see if the pt is being oxygenated
What does the oxyhemoglobin dissociation curve show?
the relationship between the partial pressure of oxygen (PaO2) and the percentage of saturation of oxygen (SaO2)
What is PaO2?
partial pressure of alveolar oxygen
What is partial pressure?
the pressure exerted by each type of gas in a mixture of gases
What is SaO2 and what can affect it?
percentage of saturation of oxygen
hydrogen ion concentration
What does an
in SaO2 do to the oxyhemoglobin dissociation curve?
shifts to right
What happens when the oxyhemoglobin dissociation curve shifts to the right?
less oxygen is picked up in the lungs, but more oxygen is released to the tissues if PaO2 is unchanged
bonds are more loose
What does a
in SaO2 do to the oxyhemoglobin dissociation curve?
shifts to left
What happens when the oxyhemoglobin dissociation curve shifts to the left?
more oxygen is picked up in the lungs, but less oxygen is given up to the tissues if the PaO2 is unchanged
bonds between oxygen and hemoglobin become stronger
What is the normal pH of arterial blood?
What is the normal Co2 of arterial blood?
What is the normal HCO3 of arterial blood?
When a pH is below 7.35, it is said to be ___________.
When a pH is above 7.45, it is said to be ___________.
The ______ regulate the CO2 and can be corrected ________. Normally a(n) ________.
The _______ regulate the HCO3 and is ______ to fix. Normally a(n) ________.
What are the characteristics of uncomensated ABG?
one abnormal value
one normal value
What are the characteristics of a partially compensated ABG?
two abnormal values
What are the characteristics of a compensated ABG?
2 abnormal values
causes of normal anion gap metabolic acidosis
*most commonly due to renal failure
lower intestinal fistulas
use of diurectics
early renal insufficiency
excessive administration of chloride
administration of parenteral nutrition w/o bicarb or bicarb producing solutes (lactate)
causes of high anion gap metabolic acidosis
late phase of salicylate poisoning
methanol or ethylene glycol toxicity
ketoacidosis w/ starvation
signs and symptoms of metabolic acidosis
^ RR and depth
peripheral vasodilation and decreased cardiac output when pH <7
cold, clammy skin
treatment for metabolic acidosis?
directed at correcting metabolic imbalance
decrease chloride intake if that is the problem
administer bicarb when necessary
monitor K+ level closely
if chronic, low Ca+ treated before chronic metabolic acidosis treated to avoid tetany from increase in pH and decrease in ionized Ca+
may receive hemodialysis or peritoneal dialysis
causes of acute metabolic alkalosis?
*most common cause is vomiting or gastric suctioning
pyloric stenosis (only gastric fluid is lost)
loss of K+
diuretic therapy that promotes excretion of K+ (thiazides, furosemide)
excessive adrenocorticosteriod hormones (hyperaldosteronism, Cushing's syndrome)
excessive alkali ingestion from antacids containing bicarb
use of Na+ bicarb during CPR
causes of chronic metabolic alkalosis?
long term diuretic therapy use
external drainage of gastric fluids
significant K+ depletion
chronic ingestion of milk and calcium carbonate
signs and symptoms of metabolic alkalosis
tingling of fingers and toes
symptoms of hypocalcemia
respirations are depressed as a compensatory action
ventricular disturbances may occur
frequent PVC's or U waves seen as K+ decreases
treatment of metabolic alkalosis
aimed at correcting underlying acid-base disorder
monitor I&O's closely (b/c of volume depletion w/GI loss)
administer chloride so kidneys can absorb Na+ w/ Cl- (allows excretion of excess bicarb)
restore normal fluid volume w/ NaCl solutions
administer K+ if hypokalemic
H2 receptor agonist to reduce production of gastric acid to reduce metabolic alkalosis associated w/ gastric suctioning (ex. Tagament)
Carbonic anhydrase if can't tolerate rapid volume expansion (CHF)
what ALWAYS causes of respiratory acidosis?
inadequate excretion of CO2 w/ inadequate ventilation
causes elevation in plasma CO2 levels
causes of acute respiratory acidosis in emergency situations
acute pulmonary edema
aspiration of foreign object
overdose of sedatives
administration of oxygen to a pt w/ chronic hypercapnia (excessive CO2 in blood)
mechanical ventilation if rate is inadequate and CO2 is retained
what disease processes can cause respiratory acidosis?
causes of chronic respiratory acidosis
obstructive sleep apnea
what happens if the PaCO2 does not exceed the bodies ability to compensate?
pt will be asymptomatic
why do pts w/ COPD who gradually accumulate CO2 over a prolonged period of time not develop symptoms?
compensatory renal changes have had time to occur
signs and symptoms of respiratory acidosis
feeling of fullness in head
v-fib in anesthetized pt
^ ICP if severe
dilated conjuctival blood vessels
treatment of respiratory acidosis
directed at improving ventilation
bronchodilators to reduce bronchial spasms
antibiotics to fight infection
thrombolytics or anti-coagulants for PE
pulmonary hygiene measures to clear respiratory tract of mucus and purulent drainage
adequate hydration to keep mm moist and facilitate removal of secretions
supplemental O2 w/ caution if necessary
mechanical ventilation if used appropriately
semi-Fowler's position to expand chest wall
what ALWAYS causes respiratory alkalosis?
what causes hyperventilation in respiratory alkalosis?
early phase of salicylate intoxication
inappropriate ventilator settings that do NOT match pt requirements
what causes chronic respiratory alkalosis?
chronic hepatic insufficiency
signs and symptoms of respiratory alkalosis
lightheadedness due to vasoconstriction and decreased cerebral blood flow
inability to concentrate
numbness and tingling
ventricular and atrial dysrhythmias
treatment of respiratory alkalosis
depends on underlying cause
if caused by anxiety, pt instructed to breath more slowly or into closed system (paper bag) to increase CO2
sedative may be needed to relieve hyperventilation
sputum studies collection
requires doctor's order
can be collected by nurse
best to collect early in morning
can instruct pt to collect specimen themselves
should send to lab as soon as collected
2 things a pt can do that can contaminate a sputum specimen
use mouth wash
imaging studies that can be done to diagnosis respiratory illness/disease
what procedure may be done if a pt has accumulation of pleural fluid?
what is a thoracentesis?
aspiration of fluid or air from the pleural space
A thoracentesis may be preformed for ________ and/or ________ reasons.
purposes of a thoracentesis
removal of fluid and air from pleuaral cavity
aspiration of pleural fluids for analysis
instillation of meds into pleural space
what studies are ran on pleural fluid when biopsy done?
gram stain C&S
acid-fast staining and culture
differential cell count
what measure can be taken when a thoracentesis is performed to lower the rate of complications?
perform under ultrasound guidance
is a thoracentesis a sterile procedure?
True or False. A nurse does not have to obtain a consent for a thoracentesis.
What is the optimal position to place a pt in for a thoracentesis?
upright, sitting on edge of bed w/ feet supported and arms on padded side table
2 other options for positioning for thoracentesis
1. straddling chair w/ arms and head resing on the back of the chair
2. lying on unaffected side w/ the HOB elevated 30-45* if unable to assume a sitting position
rationale for upright, sitting on edge of bed and leaned over table position in thoracentesis
upright position facilitates the removal of fluid that usually localizes at the base of the thorax
a position of comfort helps the pt to relax
endoscopic procedures include: __________ and _________.
what is a bronchoscopy?
the direct inspection and examination of the larynx, trachea, and bronchi through either a flexible fiberoptic bronchoscope or a rigid bronchoscope
which type of bronchoscope is used more frequently in current practice?
flexible fiberoptic bronchoscope