RCP 105 (VENTS) midterm Flashcards
What are the effects of High PEEP?
INCREASED PAP, INCREASE CVP, DECREASE PCWP
Example sentence: High PEEP can lead to increased pulmonary artery pressure (PAP), increased central venous pressure (CVP), and decreased pulmonary capillary wedge pressure (PCWP).
Co-oximetry
uses signal extraction technology to measure a patient’s hemoglobin, oxygen content, carboxyhemoglobin, methemoglobin, pleth variability index, and perfusion index
Pulse oximetry
A device that measures the patient’s arterial oxygen saturation (SpO2) by emitting dual wavelengths of light through a pulsating vascular bed.
PaO2
oxygenation
SpO2
pule oximetry
Double-lumen tube
as 2 separate lumens, 2 cuffs, and 2 pilot balloons. (1) Used to provide independent lung ventilation where isolation of the lungs is desirable to prevent lung-to-lung spillage of blood or pus, (2) provide one-lung ventilation so that the non ventilated lung may undergo surgical procedure, (3) can provide ventilation by overcoming the persistent air leak through the fistulas
OPA
designed to relieve obstruction in the unconscious patient caused by the tongue and other soft tissue
LMA
small, triangle shaped, inflatable mask secured to a tube. Designed to seal the esophagus, providing a more patent and easily maintained airway.
ET tube
artificial airway that is passed through the mouth or nose and advanced into the trachea
Trachea tube
airway that is designed to be surgically placed below the larynx at the second tracheal ring. It relieves upper airway obstruction and may be cuffed or cuffless
NPA
relieve obstructions in the conscious or semiconscious patient caused by the tongue esophageal obturator airway. Can be used to facilitate ventilation or removal of secretions
esophageal gastric tube airway
has an opening at the distal end which allows removal or aspiration of air and gastric contents from the stomach via gastric tube. There are 2 ports on the mask; resuscitation bag must be attached to ventilation port
Laryngoscope handle
used to displace the tongue and soft tissues
Blade
Miller blade used to lift up the epiglottis while Macintosh blade placed in vallecula indirectly lifts epiglottis for visualization of vocal cords (size 3 typically used)
ET tube intubation
size 7.5 to 8 typical male size and 7.0 to 7.5 for adult females
10mL syringe
used to test the pilot balloon and inflate the cuff after intubation
water souble lubricant
used to lubricate the distal end of the ET tube for easy insertion into the trachea
tape
used to secure the ET tube so that the tube will not move too high causing, inadvertent extubation or too low leading to main-stem intubation
sethoscope
needed to auscultate bilateral breath sounds immediately after intubation
stylet
flexible but semigrid wire placed inside an endotracheal tube to provide desired curvature
topical anesthetic
may be used to numb and vasoconstrict the mucosal membrane
Magill forecps
used to perform nasal intubation under direct vision
Explain the intubation procedure
Patient must be assessed to rule out any potential contradictions
Mallampati classification method used
Class 1= conscious sedation, soft palate, fauces, uvula, anterior and posterior tonsillar pillars
Class 2= conscious sedation, soft palate, fauces, and uvula
Class 3= seek anesthesia consultation, soft palate, and base of uvula
Class 4= seek anesthesia consultation, soft palate only
Determine if the ET tube is in the correct place
If placed properly:
if patient is breathing spontaneous, bilateral breath sounds should be heard
pulse ox measurements should show immediate change
moisture and condensation will form inside the tube
CO2 indicator or end tidal CO2 monitor may be attached to end of ET tube
chest radiograph
Explain how to calculate the I:E ratio for a time-cycled, pressure-limited ventilator.
Minute volume x sum of I:E ratio (add)
ex:
Given= 12 L/min, 1:3
12 L/min x (1+3)
12 L/min x 4
= 48 L/min
Mechanical deadspace
volume of gas contained in the equipment and supplies that does not take part in gas exchange (going to vary depending on machine and patient)
Anatomic deadspace
volume occupying the conducting airways that does not take part in gas exchange (150mL adults)
Bronchitis
= inflammation of the lining of the bronchial tubes, which carry air to and from the air sacs (alveoli) of the lungs. It’s characterized by daily cough and mucus (sputum) production
General Appearance: barrel chest, clubbing and cyanosis
Respiratory Pattern: dyspnea, accessory muscle use, pursed-lip breathing
Breath Sounds: diminished aeration with bilateral expiratory wheeze
Diagnostic Chest Percussion: tympanic or hyperresonant
Cough: congested, productive thick sputum
Chest- Xray: hyperlucency, hyperinflation, increased A-P diameter, flattened diaphragm
ABG: compensated respiratory acidosis with hypoxemia and hypercapnia
Pneumonia
= An infectious inflammatory process that primarily affects the gas exchange area of the lungs causing capillary fluid to pour into the alveoli. This process leads to inflammation of the alveoli, alveolar consolidation and atelectasis.
viruses account for 50% pneumonia
General appearance: Diaphoretic, cyanotic
Respiratory Pattern: Tachypnea
BS: Crackles, bronchial, whispered pectoriloquy
Diagnostic Chest Percussion: Flat or dull note over consolidation
Cough Productive: yellow/green sputum, may also be rust color
Vitals: Fever, (bacteria >100° F and viral < 101° F) increased HR, RR and BP
Chest X-ray- Increased density in area of consolidation and atelectasis, air bronchograms possible pleural effusion
ABG-Acute alveolar hyperventilation with hypoxemia
CBC: Increased WBC with bacterial infection, decreased with viral
Culture and Sensitivity to determine cause
Emphysema
= the alveoli at the end of the smallest air passages (bronchioles) of the lungs are destroyed as a result of damaging exposure to cigarette smoke and other irritating gasses and particulate matter
Anatomic alterations:
Permanent enlargement and destruction of the air spaces distal to the terminal bronchioles
Destruction of alveolar-capillary membrane
Weakening of the distal airways, primarily the respiratory bronchioles
Air trapping and hyperinflation
Chest- Xray: hyperlucency, hyperinflation, increased A-P diameter, flattened diaphragm
ABG: compensated respiratory acidosis with hypoxemia and hypercapnia
Asthma
= A chronic, inflammatory, obstructive, non-contagious airway disease with varying levels of severity, characterized by exacerbations of wheezing and coughing
Patient Assessment-History and Physical exam
SOB-pursed-lip breathing, chest tightness
Appearance of the chest –increased A-P diameter during an attack
Respiratory Pattern- Accessory muscle usage, retractions (more so in kids)
Diagnostic Chest Percussion – hyperresonant/tympanic note
BS - Diffuse wheezing, bilateral wheezing, diminished breath sounds, prolonged expiration
Physical Appearance – diaphoresis
Vitals – tachycardia, tachypnea
Decreased blood pressure during inspiration
Increased blood pressure during expiration
Chest X-ray –During an attack increased A-P diameter, translucent lung fields, depressed or flattened diaphragm
ABG – Initially acute respiratory alkalosis with hypoxemia then acute respiratory acidosis
CHF
= left-sided heart failure
Occurs when the left ventricle is unable to pump out a sufficient amount of blood during each ventricular contraction
Determined by means of the left ventricular ejection fraction (LVEF)
Vital signs:
Increased respiratory rate (Tachypnea), heart rate (pulse), blood pressure
Cheyne-Stokes respirations
Paroxysmal nocturnal dyspnea and orthopnea
Cyanosis
Cough and sputum—frothy and pink in appearance
Pulmonary embolus
= A blood clot that becomes dislodged and travels to another part of the body
Clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by:
Atelectasis
Bronchospasm
Vitals:
Increased Respiratory rate (Tachypnea)
Stimulation of peripheral chemoreceptors
Reflexes from the aortic and carotid sinus baroreceptors
Increased heart rate (pulse)
Systemic hypotension (DECREASED blood pressure)
Cyanosis
Cough and hemoptysis
Peripheral edema and venous distention
Distended neck veins
Swollen and tender liver
Chest pain/decreased chest expansion
Syncope, light-headedness, and confusion
Abnormal heart sounds
Increased second heart sound (S2)
Increased splitting of the second heart sound (S2)
Third heart sound (or ventricular gallop)
Right ventricular heave or lift
Chest assessment findings:
Crackles
Wheezes
Pleural friction rub
ABG: Acute alveolar hyperventilation with hypoxemia (acute respiratory alkalosis)
pH= INCREASED
PaCO2= DECREASED
HCO3-= DECREASED
PaO2= DECREASED
SaO2= DECREASED
Chest radiograph:
Increased density (in infarcted areas)
Hyperradiolucency distal to the embolus
Dilation of the pulmonary arteries
Pulmonary edema
Right ventricular cardiomegaly (cor pulmonale)
Pleural effusion (usually small)
Atelectasis
= abnormal condition of the lungs characterized by the partial or total collapse of previously expanded alveoli
Diagnosis:
Physical Exam
Chest X-ray: Provides pictures of the chest to help identify areas of collapsed lung tissue (GOLD Standard)
Computed tomography (CT) scan: Creates detailed images of the lungs and chest cavity to help determine the cause of atelectasis
Bronchoscopy: A thin, flexible tube with a camera is inserted into the windpipe to detect and remove blockages
Vital signs: Increased Respiratory rate (tachypnea), Heart rate (pulse), Blood pressure
Cyanosis
Chest assessment findings:
Increased tactile and vocal fremitus
Dull percussion note
Bronchial breath sounds
Diminished breath sounds
When atelectasis is caused by mucous plugs:
Crackles
Whispered pectoriloquy
Pneumothorax
= When gas (sometimes called free air) accumulates in the pleural space
The pleural space, the visceral and parietal pleura separate, enhances the natural tendency of the lung to recoil, or collapse, the alveoli are compressed and atelectasis ensues
A restrictive lung disorder
Closed pneumothorax= Gas in the pleural space is not in direct contact with the atmosphere
Open pneumothorax= The pleural space is in direct contact with the atmosphere such that gas can move freely in and out
Tension pneumothorax= The intrapleural pressure exceeds the intra-alveolar (or atmospheric) pressure
BS: diminished/absent on affected side
CXR: all black, not able to see outlines
Vitals:
Increased respiratory rate (tachypnea)
Decreased lung compliance/increased ventilatory rate relationship
Activation of the deflation receptors
Activation of the irritant receptors
Stimulation of the J receptors
Pain/anxiety
Increased Heart rate (pulse)/Blood pressure
Cyanosis
Chest assessment findings:
Hyperresonant percussion note over the pneumothorax
Diminished breath sounds over the pneumothorax
Tracheal shift (away from the affected side in a tension pneumothorax)
Displaced heart sounds
Increased thoracic volume on the affected side (particularly in tension pneumothorax)
Bubbling from chest occurs due to air coming out
ABG for small pneumothorax= Acute alveolar hyperventilation with hypoxemia (acute respiratory alkalosis)
pH= INCREASED
PaCO2= DECREASED
HCO3-= DECREASED but normal
PaO2= DECREASED
SaO2= DECREASED
ABG for large pneumothorax= Acute ventilatory failure with hypoxemia (acute respiratory acidosis)
pH= DECREASED
PaCO2= INCREASED
HCO3-=INCREASED
PaO2= DECREASED
SaO2= DECREASED
Flail chest
= The result of double fractures of at least three or more adjacent ribs
Causes the thoracic cage to become unstable
The affected ribs paradoxically cave in (flail) during inspiration as a result of the generated subatmospheric intrapleural pressure
Compresses and restricts the underlying lung
Sharp rib fragments may also damage underlying tissue and large blood vessels
Causes a restrictive lung disorder
Anatomic alterations:
Double fracture of numerous adjacent ribs
Rib instability
Lung volume restriction
Atelectasis
Lung collapse (pneumothorax)
Lung contusions
Secondary pneumonia
Vital signs:
Increased respiratory rate (tachypnea), Heart rate (pulse), Blood pressure
Paradoxical movement of chest wall\
Pain/anxiety
Cyanosis
Diminished breath sounds: on both the affected and the unaffected sides
ABG= Acute alveolar hyperventilation with hypoxemia (acute respiratory alkalosis)
pH= INCREASED
PaCO2= DECREASED
HCO3-= DECREASED but normal
PaO2= DECREASED
SaO2= DECREASED
Bronchiectasis
= Chronic dilation and distortion of one or more bronchi as a results of excessive inflammation and destruction of bronchial walls, blood vessels, elastic tissue and smooth muscle. This results in impaired mucociliary clearance causing accumulation of copious amounts of bronchial secretions
Chest X-ray: hyperlucent lung fields, depressed or flattened flattened diaphragm, enlarged or elongated heart.
ABG: Mild to moderate cases :acute alveolar hyperventilation with hypoxemia
Severe cases: chronic ventilatory Failure with hypoxemia
Bronchogram or CT: dilated bronchi, increased bronchial wall opacity
Patient Assessment
History of pulmonary infections
General appearance: cyanosis, barrel chest, clubbing\
Respiratory Pattern: tachypnea, dyspnea, accessory muscle use, pursed-lip breathing.
BS: wheezing, diminished breath sounds
Diagnostic percussion: hyperresonat or tympanic notes
Cough: productive of purulent, foul-smelling secretions, hemoptysis, sputum will separate into 3-layers
Increased hematocrit and hemoglobin
Elevated white blood count if acutely elevated
Sputum examination:
Streptococcus pneumoniae
Haemophilus influenzae
Pseudomonas aeruginosa
Anaerobic organisms
TB
= A contagious chronic bacterial infection that primarily affects the lungs
TB pathogen, Mycobacterium tuberculosis—a rod-shaped bacterium with a waxy capsule
It may involve almost any part of the body
Anatomic:
Alveolar consolidation
Alveolar-capillary destruction
Caseous tubercles or granulomas
Cavity formation
Fibrosis and secondary calcification of the lung parenchyma
Distortion and dilation of the bronchi
Increased bronchial airway secretions
Diagnosis:
Mantoux tuberculin skin test
Acid-fast bacilli (AFB) sputum cultures
The QuantiFERON-TB Gold (QFT-G) test
The rapid Xpert MTB/RI assay
Pleural effusion
= The accumulation of fluid in the pleural space
Restrictive lung pathophysiology
Vital signs:
Increased Respiratory rate (tachypnea), Heart rate (pulse), Blood pressure
Chest pain/decreased chest expansion
BLUNTED diaphragm
Cyanosis
Cough (dry, nonproductive)
Chest assessment findings:
Tracheal shift
Decreased tactile and vocal fremitus
Dull percussion note
Diminished breath sounds
Displaced heart sounds
Pleural friction rub (occasionally)
ILD
= Refers to a broad group of inflammatory lung disorders
More than 180 diseases
Characterized by acute, subacute, or chronic inflammatory infiltration of alveolar walls by cells,
fluid, and connective tissue
If left untreated, the inflammatory process can progress to irreversible pulmonary fibrosis destruction
of the alveoli and adjacent pulmonary capillaries
fibrotic thickening of the bronchioles, alveolar ducts, and alveoli
CXR:
Granulomas
honeycombing and cavity forming
fibrocalcific pleural plaques
bronchospasms
excessive bronchial secretions
pleural effusion
Physical:
cyanosis
digital clubbing
peripheral edema
venous distension
distended neck veins
pitting edema
enlarged and tender liver
Nonproductive cough
Chest assessment findings:
Increased tactile and vocal fremitus
Dull percussion note
Bronchial breath sounds
Crackles
Pleural friction rub
Whispered pectoriloquy
Increased hematocrit and hemoglobin (polycythemia)
ABG: Acute alveolar hyperventilation with hypoxemia (acute respiratory alkalosis)
pH= INCREASED
CO2= DECREASED
HCO3= DECREASED
PaO2= DECREASED
SaO2= DECREASED
Sleep apnea
OSA= common sleep disorder that often requires lifelong care (blocked airflow)
Presence of:
Snoring
Sleep fragmentation
Periods of apnea during sleep
Nonrefreshing sleep
Persistent daytime sleepiness
Central sleep apnea= disorder characterized by the repetitive stopping or reduction of both air flow and ventilatory effort during sleep. Brain fails to transmit signals for muscles to breaths
Examples associated with it is Cheyne-Stokes breathing (CHF), medical conditions, brain stem infarction, spinal surgery, hypothyroidism, high altitude periodic breathing
Diaphragm doesn’t move
AFIB
Patients diagnosed with CSA are evaluated carefully for:
The presence of cardiac disease
Lesions involving the cerebral cortex and the brainstem
AHI =# of apneas and hypopneas
—-—————————
TST (hr)
Physical:
Apnea or hypopnea
Cyanosis
ABG: Acute alveolar hyperventilation superimposed on chronic ventilatory failure
Possible impending acute ventilatory failure
Acute ventilatory failure (acute hypoventilation) superimposed on chronic ventilatory failure
CXR:
Often normal
Right-or left-sided heart failure
ARDS
In response to injury:
Pulmonary capillaries become engorged
Permeability of the alveolar-capillary membrane increases
Interstitial and intra-alveolar edema and hemorrhage
Scattered areas of hemorrhagic alveolar consolidation
Result in a decrease in alveolar surfactant and in alveolar collapse, or atelectasis
*Create a restrictive lung disorder
Physical:
Increased Respiratory rate (tachypnea)/Heart rate (pulse)/Blood pressure
Substernal or intercostal retractions
Cyanosis
Chest assessment findings:
Dull percussion note
Bronchial breath sounds
Crackles
CXR:
Increased opacity, diffusely throughout lungs
Ground-glass appearance
ABG: Acute alveolar hyperventilation with hypoxemia (acute respiratory alkalosis)
pH= INCREASED
CO2= DECREASED
HCO3= DECREASED
PaO2= DECREASED
SaO2= DECREASED
Modes of ventilation you can use pressure support (PS) in
SIMV/VC
SIMV/PC
PS/CPAP
BiPAP
How PS helps when using SIMV
PS commonly applied in the SIMV mode when the patient takes a spontaneous breath since PS is not active during mandatory breaths. Typically used to facilitate weaning in a difficult-to-wean patient
Pressure support:
increases the patient’s spontaneous tidal volume
decreases the patient’s spontaneous frequency
decreases the work of breathing
Weaning process
Spontaneous breathing trial is the diagnostic test to determine if the patient can be successfully extubated and weaned from mechanical ventilation for 20 to 30 mins. Starts PSC at 5-10cm and decrease 3-6cm until PSV reaches 6cm H2O.
Weaning success
= Absence of ventilatory support for at least 48 hours following extubation
RSBI less than 100 breaths/min
PaO2/Fio2 greater than 150mmHg
Shunt less than 20%
Vital capacity greater than 10mL/kg
Maximal inspiratory pressure greater than -20 cmH2O (-30 is better)
Static compliance greater than 30mL
Deadspace want it less than 60% while intubated
PEEP less than 8cm H2O
pH greater than 7.25
PS less than 8cm
Greater than 3 mins of spontaneous breathing
Weaning faliure
= failure of SPT (1) increase of airflow resistance, (2) decrease of compliance, (3) respiratory muscle fatigue
Occurs within the first 20 to 30 min
Clinical signs and symptoms include
Agitation
Anxiety
Diminished mental status
Diaphoresis
Cyanosis
Increased work of breathing
Sinus tachycardia
heart rate greater than 100 bpm (normal P-QRS-T pattern)
sinus bradycardia
heart rate less than 60 bpm (normal P-QRS-T pattern)
premature ventricular contractions (PVCs)
= not preceded by a P wave and QRS complex is wide, bizarre, and not normal
Ventricular tachycardia
P wave is generally not noticeable and QRS is wide, bizarre, and T wave may not be separated from QRS complex
Ventricular fibrillation
chaotic electrical activity and cardiac activity, ventricles quiver out of control and no perfusion beat-producing rhythm
no cardiac output, blood pressure, PT can die in minutes without treatment
Asystole
= complete absence of electrical and mechanical activity
cardiac activity and blood pressure fall to 0
Heart blocks
First-degree AV block involves the consistent prolongation of the PR interval due to delayed conduction via the atrioventricular node
Sensorium
what is their level of consciouness
Static compliance
= reflects the elastic properties of the lung and chest wall (resistance)
Corrected Tidal volume፥(plateau pressure-PEEP)
Dynamic compliance
= reflects the airway resistance and elastic properties of the lung and chest wall
Corrected tidal volume፥(PIP-PEEP)
Airway resistance
(0.5-2.5 cmH2O)= airflow obstruction in the airways
radius of the airway decreases and airway resistance increases
hypoventilation may result if patient is unable to overcome airway resistance by increasing work of breathing
Physiological effects of mechanical ventilation
acute airflow obstruction
deadspace ventilation
congenital heart disease
cardiovascular decompensation
shock
increased metabolic rate
drugs
decreased compliance
Propofol- aka Diprivan
used for hypnotic effect
Intravenous use
GABA-activated chloride ion channel
Adverse effects:
Apnea
Bradycardia
Laryngospasm and bronchospasm
Coughing
Dyspnea
Hypotension
Burning or pain at infusion site
Discoloration of urine to green or brown
Increased calories because of the oil-in-water formulation
Haloperidol- aka Haldol
used to control delirium in mechanically ventilated patients
Reversible causes of delirium should be ruled out before using haloperidol (see next slide)
Haloperidol blocks dopamine receptors in the CNS (limbic, basal ganglia, and brainstem) producing a calming effect
Haloperidol also has antiemetic effect
Adverse effects:
Blockade of dopamine receptors in the CNS may interfere with normal motor function
Dexmedetomidine- aka Precedex
for patients undergoing uncomfortable procedures (e.g., mechanical ventilation, cardiac or vascular surgeries, colonoscopy)
provides sedation, anxiolysis, and analgesia without respiratory depression
An alpha-2 adrenoreceptor agonist
Provides sedation and anxiolysis via receptors within the locus coeruleus (group of neurons in the pons)
Provides analgesia via receptors in the spinal cord
Adverse effects:
Hypotension, bradycardia, and sinus arrest are potential adverse effects because dexmedetomidine reduces sympathetic activity
Transient hypertension may occur
Transient neurological abnormalities may occur in children upon discontinuance
Nitric oxide
- FDA approved for only newborns
Persistent pulmonary hypertension and hypoxemic respiratory failure of the newborn
Respiratory distress syndrome and hypoxemic respiratory failure of older infants and children
Acute respiratory distress syndrome
Inadequate cardiopulmonary hemodynamics in infants due to lack of pulmonary blood flow and oxygenation
local vasodilation of vascular smooth muscle
Adverse effects:
When combined with oxygen, NO is converted to NO2 (nitrogen dioxide)
At a level of >10 ppm, NO2 can cause cell damage, hemorrhage, pulmonary edema, and death
NO and NO2 may be converted to nitric acid (HNO3) and nitrous acid (HNO2)
HNO3 and HNO2 may cause lung inflammation (interstitial pneumonia)
NO is inactivated by combining with hemoglobin to form methemoglobin (methemoglobinemia)
NO causes inhibition of platelet aggregation and negative inotropic effect
PSV
= variation of the spontaneous mode of ventilation that augments a patient’s spontaneous effort with positive pressure
patient spontaneously breathing
facilitate weaning in a difficult-to-wean patient
CPAP
= PEEP applied to the airway of a patient who is breathing spontaneously
intrapulmonary shunting
refractory hypoxemia
decreased FRC
lung compliance
auto-PEEP not responding to adjustments of ventilatory settings
can sustain lung functions
BIPAP
= applies independent positive pressure pressures (PAP) to both inspiration and expiration
preventing intubation of the end-stage COPD patient
supporting patient with chronic ventilatory failure
restrictive chest wall disease
neuromuscular disease
nocturnal hypoventilation
CMV
= ventilator delivers the preset tidal volume at a set time interval (time-triggered frequency) (controls patients tidal volume, respiratory, minute ventilation)
if patient ¨fights¨ the ventilator in the initial stages of mechanical ventilatory support
tetanus or other seizure activity
complete rest for the patient for 24 hour period
patient with a crush chest injury
SIMV/VC
= patient spontaneously breathes while giving mandatory breathes when needed
ventilatory support
patient provides part of minute ventilation
SIMV/PC
= patient spontaneously breathing while time triggered by present frequency
severe ARDS (need high PIP)
AC/VC
= mandatory mechanical breaths may be patient-triggered by the patient’s spontaneous inspiratory efforts (assist) or time-triggered by a present frequency (control)
provide full ventilatory support
stable respiratory drive
AC/PC
= mandatory pressure-controlled breathes are time-triggered by a preset frequency (pressure plateau created)
severe ARDS (need high PIP)
PRVC
= provides volume-controlled breaths with the lowest pressure possible by altering the flow and inspiratory time
achieve volume support while keeping the PIP at a lowest level possible
MMV
= causes an increase of mandatory frequency when the patients spontaneously breathing level becomes inadequate (safe minute ventilation)
prevent hypercapnia
preventing hypoventilation
preventing respiratory acidosis
CPAP
Its positive pressure that is applied to a patient that is spontaneously breathing.
when PEEP is applied to spontaneous breathing patient, airway pressure is called CPAP
PEEP
= airway pressure strategy, and ventilation that increases the end, expiratory or baseline airway pressure to value greater than atmospheric pressure
EPAP
= airway pressure that is above 0cm H2O during the expiratory phase of a respiratory cycle
Physiology:
if the force of elastic recoil is increased due to decrease in compliance, the alveolar volume will decrease
if lung compliance continues to deteriorate → elastic recoil forces become great enough to overcome normal alveolar distending pressure → alveolar collapse and intrapulmonary shunting
Poiseuille’s Law and how it relates to work of breathing
= work of breathing increases by a factor of 16-fold when the radius of the airway is reduced by half its original size
driving pressure=airflow/radius 4
Extubation procedure
procedure explained to patient
patient in Fowles (semi-sitting) positon
hyperinflation and oxygenation provided with manual resuscitator via ET tube
ET tube suction
cuff deflated
ET tube removed
encourage patient to breathe deeply and cough
suction secretions
vital signs, ABG, signs of tissue value assessed
CVP measured
= by a central venous catheter placed through either the subclavian or internal jugular veins, measured in the vena cava or right atrium
how much blood is getting pumped to right side of the heart
Low exhaled volume
= should be set at 100mL lower than expired mechanical tidal volume
alarm triggered if patient does not exhale an adequate tidal volume
Low inspiratory pressure
= should be set at 10-15cmH2O below the observed PIP
alarm triggered if PIP is less than alarm setting
High inspiratory pressure
= should be set 10-15cmH2O above observed PIP
alarm triggered when PIP is equal or higher than the high pressure limit
Apnea
= should be set 15-20 seconds time delay
triggered in circuit disconnection, ET suctioning
High frequency
= should be set at 10/min over the observed frequency
triggering is a sign of respiratory distress
High/Low FIO2
= should be set 5-10% over and under analyzed FIO2
PEEP benefits/complications
Benefits:
reinflates collapsed alveoli and supports
maintains alveolar inflation during exhalation
Complications:
decreased venous return
decrease cardiac output
barotrauma
increased intracranial pressure
alterations of renal functions
alterations in water metabolism
Square (constant) flow
provides an even, peak flow during the entire inspiratory phase
Accelerating (ascending) flow
may improve distribution of ventilation in patients with partial airway obstruction
Decelerating (descending) flow
produces a high initial inspiratory pressure and the decrease in flow may help improve distribution of tidal volume and gas exchange
COPD → may reduce PIP, MAP, physiological deadspace, and PaCO2
Sine wave
improve distribution of ventilation and therefore improve gas exchange (similar to spontaneous breathing flow)
ET suctioning
wash hands and glove
gather all suction supplies
explain procedure to patient
adjust vacuum to 100mmHg
preoxygenate patient
put sterile water in container
test vacuum with suction
insert catheter and advance until resistance (cough)
pull catheter back (10-15 seconds)
Complications:
suction induced hypoxemia
impeding airflow
dislodging of bacteria into lower airway
Ventilatory faliure
= failure of the respiratory system to remove CO2 from the body, resulting in an abnormally high PaCO2. Occurs when the patient’s minute ventilation cannot keep up with the CO2 production
Hypoexmia
= reduced oxygen in the blood
ABG used to evaluate patient’s oxygenation status
prevent or treat skin breakdown caused by ET tubes or BIPAP masks
area clean, dry
adjustment of tube every vent check
proper oral care
prevent drying of the airway in BIPAP and mechanically ventilated patients
heated humidification, heated wire circuit, a heat-moisture exchanger (HME)
Alpha/Beta receptors
Alpha 1= peripheral blood vessels
Alpha 2= presynaptic sympathetic neurons, CNS
Beta 1= heart
Beta 2= smooth muscle (bronchial), cardiac muscle
Beta 3= lipocytes
Basic ventilator settings on mechanical ventilator
mode
frequency
tidal volume
FIO2
I:E ratio
inspiratory flow pattern
alarm limits
NPPV successfull in
= in the management of airflow obstruction in sleep apnea and in the reduction of respiratory workload in gross obesity
Indications for mechanical ventilation
Drug overdose (central hypoventilation/acute respiratory insufficiency)
Acute spinal cord injury (respiratory paralysis)
Head trauma (abnormal respiratory pattern)
Neurologic dysfunction (coma/stroke)
sleep disorders (CSA/OSA)
metabolic alkalosis
acute airflow obstruction (COPD)
Dead space ventilation (pulmonary embolism/decreased in CO)
Congestive heart diseases
Cardiovascular decompensation (decreased CO/VQ mismatch)
Shock (blood loss/CHF)
Increased metabolic rate (fever/increased WOB)
Decreased compliance (ARDS/atelectasis)
drugs (acute pulmonary edema/bronchospasms)
chest trauma (flail/pneumothorax)
premature births (idiopathic respiratory distress syndrome)
electrolyte imbalance (hyperkalemia)
Geratric patients (fatigue)
Circuit change
The more we break the circuit, the more we introduce to the circuit (infection control)
Nasal mask (interface NPPV)
= a mask that covers only the nose
Benefits:
comfort
patient compliance
Risk:
gas leaks
nasal dryness
drainage
Oronasal mask (NPPV interface)
= covers the nose and mouth
Benefits:
good seal
more effective ventilation
Risk:
claustrophobia
patient noncompliance
regurgitation/aspiration
asphyxiation in power or gas outage
alarm/monitor necessary
Nasal pillow (NPPV interface)
= smaller nasal mask
nasal congestion
gas leaks
nose bleed
dry/sore mouth
Full face mask (NPPV interface)
= covers entire patients face
Control circuit on vent
= the system that governs or controls the ventilator drive mechanism or output control value/ responsible for characteristics output waveforms
Open loop
=desired output is selected and ventilatory achieves the desired output
Closed loop
=desired output is selected and ventilatory achieves the desired output
Indwelling arterial catheter
= a thin, flexible tube inserted into an artery to provide continuous access to arterial blood and blood pressure
Oral intubation
= done in emergency situations
Nasal intubation
= time consuming and suitable in elective intubation
Stroke volume index
SV= CO/HR
Normal range → 40-80 mL
Hypoxemia levels
Normal → 80-100mmHg
Mild → 60-79mmHg
Moderate → 40-59
Severe → less than 40
SIMV
mode in which the ventilator drives either assisted breaths to patient at the beginning of a spontaneous breath or time-triggered mandatory breaths
time triggered or patient triggered
AC
each control breath provides the patient with a present, ventilator-delivered tidal volume
Assisted- patient triggered
Control- time triggered
does not allow spontaneous breathing
Acetylcholine
Acetylcholine is released when the parasympathetic system is stimulated
Pulmonary artery catheter
pressure readings and waveforms are monitored to determine the catheter’s position as it moves through the right atrium (RA), right ventricle (RV), pulmonary artery (PA), and into a pulmonary capillary wedge pressure (PCWP) position
after the PCWP reading, the balloon is deflated to allow blood to flow past the tip of the catheter
ET tube intubation/use complications/hazards
trauma to teeth and soft tissues
esophageal intubation
vomiting/aspiration
hypoxia
arrhythmias
bradycardia
obstruction
pneumonia
kinking
mucosal injuries
laryngeal damage
improper tube position
pressure sore
inadvertent extubation
sinusitis
Hemoglobin affecting SaO2/SpO2
= protein continuing iron that facilitates the transports oxygen in RBC
PaO2 measures the amount of oxygen dissolved in the plasma whereas vast majority of oxygen in the blood is combined with or carried by hemoglobins
PaO2 may be inadequate if patients hemoglobin levels are below normal (anemia)
RSI
= describes an urgent need to gain control of a patient’s airway
Steps:
preparations
pre-RSI medications
cricoid pressure
intubation
post RSI stabilization
RSI MEDS
Etomidate (Amidate)= sedation and induction
= decreases cerebral metabolic rate, cerebral blood flow, and intracranial pressure
Etomidate binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open
Succinylcholine= paralytic agent
= depolarizing skeletal muscle relaxant used adjunctly to anesthesia and for skeletal muscle relaxation during intubation, mechanical ventilation, and surgical procedures
It binds to the post-synaptic cholinergic receptors found on motor endplates, thereby inducing first transient fasciculations followed by skeletal muscle paralysis
VAP
= infection of the lung parenchyma that is related to any or multiple events that the patient undergoes during mechanical ventilation that happens after 48 hours
Prevent:
proper handwashing techniques
closed suction systems
continuous feed humidification systems
change of ventilator circuit only when visibly soiled
elevated head of 30-45 degrees
Kidneys
= filters dissolved particles from blood and selectively reabsorbs the substances that are needed to maintain normal composition of body fluid
Impending ventilatory faliure
= A gradual increase of PaCo2 caused by deteriorating lung functions with increased work of breathing/minute ventilation to compensate
PaCo2 increases and pH falls → initiated mechanical ventilation
Gram stain
identifies whether bacteria are gram positive or gram negative takes 1 hour
Acid-fast sputum
performed to determine acid fast bacilli (Mycobacterium tuberculosis)
Silver stain
can be used as a diagnostic tool for bacterial and fungal infections such as infections caused by Pseudomonas app, Treponema palladium, Helicobacter pylori, Legionella, Leptospira, Bartonella, Pneumocystis, Candida, Histoplasma, Cryptococcus
Culture test
identifies the bacteria present and takes 48 to 72 hours
Sensitivty test
identifies what antibiotics will kill the bacteria takes 48 to 72 hours
Hypokalemia signs
Hypokalemia (below 3):
Decreased muscle functions
Flattened T wave and depressed ST segment on ECG
Arrhythmias
Decreased bowel activity, diminished or absent bowel sounds
Hyperkalemia signs
Hyperkalemia (above 5):
Increased neuromuscular conduction
Elevated T wave and depressed ST segment on ECG (mild)
Cardiac arrest
Increased bowel activity
Flow
= the volume of gas delivered over time, usually measured in liters per minute
Unit of volume፥unit of time
Explain how to lower the I:E ratio on a volume-controlled, flow-limited ventilator.
I time= time for each breath x [I ratio/sum of I:E ratio]
ex:
Given= f=16/min → 60፥16 = 3.75 seconds
Desired I:E ratio 1:4
= 3.75 sec x [1/(1+4)]
3.75 x (⅕)
3.75 sec ፥5
= 0.75 sec
Explain how TV is increased when using AC/PC or SIMC/PC
= Increasing respiratory rate may manage this increase in minute ventilation, but if this is not feasible, increasing the tidal volume can increase plateau pressures and create barotrauma.
Explain how to normalize a high PaCO2 on a vent or BIPAP.
= minute ventilation required needs to be increased → increase ventilatory frequency
- Decrease or remove deadspace
- Increase Tidal Volume
- Increase Respiratory Rate
Explain how to normalize a high PaO2 on a vent or BIPAP.
- FIRST- decrease FIO2 to less than .60
- THEN - decrease PEEP
Explain how to normalize a low PaCO2 on a vent or BIPAP.
- Increase Deadspace
- Decrease the Respiratory Rate
- Decrease the Tidal Volume
Explain how to normalize a low PaO2 on a vent or BIPAP.
- FIRST - increase Fio2 by 5-10% (up to 60%)
- THEN - Increase PEEP levels by 5cmH20 until:
- acceptable oxygenation is achieved
- unacceptable side-effects occur (decrease in compliance, decrease in cardiac function, barotrauma)
Explain how and provide and example of how initial vent settings should be set.
Mode: control or AC
Frequency: 10-12/min
Tv: 10-12 mL/kg
FIO2: 40%, 100% if CO2 toxicity or full cardiac arrest
PEEP: 5cm H2O
I:E ratio: 1:2 normal or 1:4 COPD/asthma
Why do we monitor the PIP.
To measure elastic pressure, how well the lungs are reacting to treatment, if lungs are getting better or worse, and compliance. How much pressure were putting on the vessels
