Needs Flashcards
What are the physiologic objectives of CMV?
- To support or manipulate pulmonary gas exchange
- Reduce WOB
- Increase lung volume
- Minimize cardiac impairment
What are the clinical objectives for CMV?
- Reverse acute respiratory acidosis
- Reverse hypoxemia
- Relieve respiratory distress
What are the sudden signs of distress?
- Cyanotic
- Anxious
- Pale
- Eyes wide open
- Diaphoretic
What are the physical signs of distress?
- Patient complains of not getting enough air
- Abnormal breath sounds
- Intercostal spaces may appear indented during active inspiration
How would you recognize ARF?
- LOC
- Cyanosis, pale, diaphoretic
- Vital signs assessed
Who needs CMV?
- Apnea
- Acute respiratory failure (type I and II)
- Impeding respiratory failure
What can cause apnea?
- CA
- Overdose
- Severe hypoxia
- Head trauma
- High cervical spine injury
What is acute respiratory failure?
Any condition when respiratory activity is inadequate to maintain O2 uptake and CO2 clearance
What is a typical ABG for acute respiratory failure?
pH50torr
PaO2<60torr
What are the two types of acute respiratory failure?
- Hypoxic respiratory failure (type 1)
- Hypercapnia respiratory failure (type 2)
What is another name for hypercapnia respiratory failure (type 2)?
Hypoxic lung failure
What is hypercapnia respiratory failure (type 2)?
- Problem with respiratory muscles
- Caused by diseases that increase WOB
- Primary defect is ventilation
- Severe low V/Q
What are the causes of hypercapnia respiratory failure (type 2)?
- CNS (decreased or increased drive)
- Neuromuscular disorders
- Disorders that increase WOB
- Drugs that increase WOB
____ is characterized by a ____ in alveolar ventilation and an ____ in PaCO2
ARF type 2; reduction; increase
What are the 6 things that contribute to a CNS decrease drive in ARF type 2?
- Depressant drugs
- Acid/base abnormals
- Sleep disorders
- Head trauma
- Hypothyroidism
- Inappropriate oxygen
What are the 3 things that contribute to a CNS increase drive in ARF type 2?
- Metabolic acidosis
- Increased metabolic rate
- Anxiety associated with dyspnea
What neuromuscular disorders cause ARF type 2?
- Hypoglycemia
- Impaired muscle function
- Motor nerve damage
- Paralytic drugs
- Drugs that affect neurotransmission
- MG and GB
Normally, WOB take ___ of total oxygen consumption
1%-4%
What can cause an increased WOB in ARF type 2?
- Decreased lung expansion, thoracic excursion and diaphragm excursion
- Increased deadspace diseases, RAW, metabolic rate
- Acute lung injury
- Congenital heart disease
- Shock
- Drugs
What could cause decreased lung expansion?
Pleural effusion
What could cause decreased thoracic excursion?
Chest surgery
What could cause decreased diaphragm excursion?
Obesity
What could cause an increase in deadspace diseases?
Emphysema
What could cause an increase in RAW?
COPD
What is an example of an acute lung injury?
ARDS
What could cause congenital heart disease?
Decreased CMO
What could cause shock?
Blood loss
What could cause an increase in metabolic rate?
Fever
What drugs could cause an increased WOB in ARF type 2?
- Narcotics (pulmonary edema)
- Insulin (bronchospasm)
What is ARF type 1?
Primary problem is oxgenation. Hypoxemic respiratory failure (severe refractory hypoxemia)
What are 2 ways you could try to treat ARF type 1?
- Oxygen
- PEEP/CPAP
What does a typical ABG for ARF type 1 look like?
- PaO2 is low
- PaCO2 is normal to low
- PaO2/FiO2<200
What are 5 things that cause ARF type 1?
- Decreased inspired Oxygen
- Diffusion Impairment
- Perfusion/Diffusion impairment
- Shunt
- Ventilation/Perfusion mismatch
True or false: Ventilation/perfusion mismatch responds to oxygen
True
What is the clinical presention of V/Q mismatch?
- Dyspnea
- Accessory muscles
- Tachycardia
- Tachypnea
What is diffusion impairment in ARF type 1?
Difficulty with movement across alveolar capillary membrane due to pressure gradient
What causes diffusion impairment in ARF type 1?
- In exercise, blood flow increases, which limits time for exchange
- Pulmonary vascular abnormalities
What are some examples of pulmonary vascular abnormalities?
- Pulmonary embolism
- Anemia
- Pulmonary hypertension
What causes perfusion/diffusion impairment in ARF type 1?
- Liver disease
- Cirrhosis
True or false: perfusion/diffusion is rare and does respond to oxygen
True
What is a shunt?
No ventilation to match perfusion
What is a physiologic shunt in ARF type 1?
Alveoli collapse, filled with fluid or exudate
True or false: a shunt responds to oxygen
False
What is the clinical presentation of a shunt in ARF type 1?
- CXR white out
- Unilateral absence of BS may indicate collapse, mass or effusion
- Bilateral/unilateral crackles due to alveolar filling process
- Asymmetrical chest expansion
What diseases could cause ARF type 1?
- Pulmonary emboli
- ARDS
- Anat/phys shunt
- Severe atelectasis
- CO poisoing
What is refractory hypoxemia also known as and what therapy is used to treat it?
Severe oxygenation deficit; PEEP therapy
What is impending respiratory failure?
- Patient has an extreme WOD
- RR>35
- Diaphoretic
- Use of accessory muscles
What is a typical ABG for a person with impending respiratory failure?
- pH normal or increased
- PaCO2 decreased (increased in late stage)
- O2 normal or decreased
What are 5 notable changes in a person with impending respiratory failure?
- Paradoxical breathing
- Retractions
- Extreme fatigue
- Vt greater % of VC
- Worsening pulmonary or pleural infection
What are the respiratory clinical findings for hypoxia?
Tachypnea for both mild/moderate and severe
What are the cardiovascular clinical findings for hypoxia?
Tachycardia for both mild/moderate and severe
What are the neurological clinical findings for hypoxia?
- Disorientation (mild/moderate)
- Confusion (severe)
What are the respiratory clinical findings for hypercapnia?
Tachypnea for both mild/moderate and severe
What are the cardiovascular clinical findings for hypercapnia?
Tachycardia for both mild/moderate and severe
What are the neurologic clinical findings for hypercapnia?
- Drowsiness (mild/moderate)
- Hallucinations (severe)
What are the clinical signs of hypercapnia?
- Sweating
- Redness
What are the best indicators for inadequate alveolar ventilation?
- PaCO2
- pH
What are the best indicators for inadequate lung expansion?
- Rate
- Vt
- VC
What are the best indicators for inadequate respiratory muscle strength?
- MIP
- VC
What are the best indicators for excessive WOB?
- Rate
- VD/VT
What is the best indicator for an unstable ventilatory drive?
Breathing pattern
What is the best indicator for severe hypoxemia?
PaO2/FiO2
What 5 things should you look at when assessing a patient?
- LOC
- Skin color
- Signs of hypoxia or hypercapnia
- Vital signs
- WOB
What is the cause of tachycardia if the heart rate decreases by 10 after several minutes on oxygen?
Hypoxia
What is the cause of tachycardia if the heart rate does not decrease after several minutes on oxygen?
Shunting
What therapy is recommended to treat CHF?
- NPPV
- BiPAP mask
What therapy is recommended to treat slowly reversible hypoxemic respiratory failure?
- Intubate
- High inspired FiO2
- PEEP
- Inverse ratio
- PCV
What therapy is recommended to treat acute alveolar hypoventilation?
- A/C
- SIMV with high back up rate
- PSV with high pressure
What therapy is recommended to treat chronic alveolar hypoventilation?
- NPPV
- BiPAP
What therapy is recommended to treat altered mental status?
- Intubate
- A/C
- SIMV with adequate back up rate
What therapy is recommended to treat acute respiratory muscle fatigue?
- BiPAP
- Intubate
- A/C
- SIMV with adequate back up rate
What therapy is recommended to treat chronic respiratory muscle fatigue?
Night time BiPAP with A/C or SIMV with tracheostomy
What are the contraindications for CMV?
- Patient’s informed request
- Untreated tension pneumothorax
- Medical futility
