Acute resp failure/ARDS/ mechanical vent Flashcards
Acute resp failure overview
- Failure for the lungs to provide adequate ventilation and perfusion
- Hypoxia+hypercapnia+acidosis
Acute resp failure patho
- Most common organ failure seen in critical care environment and can be observed with other disease states
- Fluid or some other disease process interferes with the alveoli, impaired gas exchange
Causes of Acute resp failure
- Impaired CNS function: Drug, head trauma, infection, hemorrhage, sleep apnea
- Neuromuscular dysfunction (MG, GBS, ALS. SCI)
- Musculoskeletal dysfunction: Chest trauma, kyphosis, malnutrition
- Pulmonary dysfunction:COPD asthma, CF, pneumonia, ards, PE
- Post op period: Due to anesthesia and sedation
Three acute respiratory failure categories
- Failure in oxygenation
- Failure in ventilation
- Failure in perfusion
Acute resp failure categories: Oxygenation failure
- V/Q mismatch
- Hypoventilation
- Intrapulmonary shunting
- PE
- Pulmonary edema
- COPD
- Bronchitis
- Pneumonia
- Decreased CO anemia= Hypoxemic resp failure
Anemia is a huge one
Acute resp failure categories: Ventilation failure
- Hypercapnia
- Alveolar and art oxy levels are low due to not getting into lungs
- CO2 increased (Its not exhaled)
- Alveolar hypoventilation
3 diagnostic test for resp failure
- Chest X ray
- ECG
- ABG
PH: 7.5
PaCO2: 28 mmHg
PaO2: 58 mm Hg
HCO3: 24 mEq/L
SaO2 of 89% and RR of 28
What is the issues
- Resp alk that is uncompensated
Hypoxemic Oxygenation failure: PaO2 and PaCO2
- PaO2 less than 60 mmHg and a low or normal PaCO2
Hypercapnic Ventilation failure: PaCO2
- PaCO2 will be greater than 50 mmHg
- Ph will likely be acidotic can be (alkylytic as well)
- Buffers like bicarb will be normal or a mild increase
Early signs of resp failure
- Restlessness/ anxiety
- Fatigue
- Headache
- Dyspnea
- Air hunger
- Tachycardia
- Hypertension
- Use of accessory muscles and decreased breath sounds
Later signs of resp failure
- Hypoxemia progresses
- Increased confusion
- Lethargy
- tachypnea
- Central cyanosis
- Diaphoresis
- Resp arrest
Venturi mask
- High flow O2 system
- The most precise, in delivering O2
Medical mgmt of acute resp failure
- Correct underlying cause
- Restore adequate gas exchange
- Non-invasive or invasive ventilation
- BIPAP, CPAP
- intubation
- Mechanical ventilation
Nursing mgmt of acute resp failure
- Assess reso status, LOC, ABG vitals
- T/P/ ROM
- Can they protect their airway/ or they getting vented
- Skin care
- Mouth care
- Emotional support, update family, alternative communication methods
- Assist with intubation and mechanical vent
- Tach care and suctioning
- Preventing aspiration
Acute resp distress syndrome (ARDS) : Overview
- Clinical syndrome: (Collection of all the S+S)
- Severe Inflammatory process with alveolar dmg
- Pul edema, lung infiltrates, Hypoxemia
- Hypoxemia is Unresponsive to O2 supplementation
- Super high mortality rate, 27-50% HCAP or sepsis
Can you give O2 supplementation with ARDS
- You can, but it wont do anything. There is dmg to the alveoli so it won’t help with oxygenation
Patho of ARDS
ACUTE lung injury
* Initiation of inflammatory immune response
* Release of mediators
* Increased capillary membrane permeability
* Alveolar flooding with Fluid after loss of surfactant
* Alveolar collapse
* Increased work of breathing
* Decrease in airway diameter
* Increase in airway resistance, decreased lung compliance
* Increased work of breathing
* Injury to pulmonary vasculature
* Pulmonary vasoconstriction, micro emboli formation and pulmonary hypertension
* Alveolar dead space leading to increased work of breathing
* Decreased cardiac output
Increased work of breathing leading to alveolar hypoventilation and intrapulmonary shunting –> Hypoxemia
P/F ratio
Po2 divided by the FiO2 in an ABG.
Normal is 400 anything less than 300 is bad
Causes of ARDS: Direct injury
- Aspiration of gastric content
- Pulmonary contusion (Bruising)
- Near drowning
- Inhalation of smoke or toxic substances
- Viral and bacterial pneumonia
- O2 tox
Causes of ARDS: Indirect injury
- Systemic Sepsis
- Hypovolemic shock associated with chest trauma or sepsis (Did not respond to antibiotics)
- Acute pancreatitis
- Fat emboli
- Trauma
- Disseminated intravascular coagulation (DIC)
- Massive blood transfusions
PEEP
- Positive end expiratory pressure
- Helps with conditions like ARDS to keep the alveoli open
- 10-15 cm/H2O is recommended amount of pressure to provide the most benefit with the least amount of trauma
Continuous Positive airway pressure (CPAP)
- Form of PEEP
- Delivers the same continuous pressure throughout the respiratory cycle
- Decreases alveolar dead space and improves intrapulmonary shunt by opening the alveoli
- Decreases atelectasis, reduces work of breathing and reduces hypoxia
Bilevel Positive airway pressure (BiPAP)
- Provides two pressure levels, inspiratory and expiratory (IPAP/EPAP) pressure during inspiration is greater than expiratory
- BIPAP helps maintain open airways and increase tidal volume and alveolar ventilation. Improves hypercarbia and decreases the work of breathing using pressure support at inspiration
- EPAP helps increase functional residual capacity and improves hypoxemia by keeping alveoli inflated during expiration
Adverse effects of PEEP (CPAP/BiPAP)
- Increased end expiratory pressure causes increased intrathoracic pressure leading to decreased BP/ CO
- Barotrauma is also a risk especially with higher levels of peep than needed
- Pressure of 10-15 is usually adequate to provide the most positive benefits of PEEP
Mild ARDS
- P/F ratio of 200-300 with CPAP or Peep value of at least 5 cm H20
Moderate ARDS
P/F ratio of 100-200 with CPAP or PEEP value of at least 5 cm H2O
Severe ARDS
P/F ratio of under 100 with CPAP or PEEP value of at least 5 cm H20
PH: 7.21
PaCO2 60.7
PaO2 65 mmHg
HCO3 24 mEq/L
SaO2: 86.9 with PF ratio of 100
Echo within normal limits
Whats the acid base
Resp acidosis, uncompensated
Chest X ray with an ARDS patient
White out, full of fluid
Assessment and diagnostics findings ARDS
- Pul: intercostal retractions with crackles and persistent hypoxia
- Diagnostic test
- BNP, Echo, Pa catheterization
- Pulmonary edema
- Worsening pulmonary infiltrates
- Increased alveolar dead space (Vent to alveoli but poor perfusion because fluid
- Decreased pulmonary compliance/ stiff lung making it difficult to vent
When should a patient get intubated
- When they can no longer protect their airway and PEEP isn’t working
Medical mgmt of ARDS
- Identify and treat underlying cause
- Supportive therapy: ET intubation and mechanical vent
- Volume and nutritional support: IV fluid and tube feeding (Prevent ileus and get cal)
- Hypovolemia due to leakage of fluid to interstitial spaces and decreased CO (Vasopressors)
- Prone positioning
- Sedation (Pt doesnt like tube in their face)
Is there a specific pharm treatment for ARDS
Nah there isn’t a cure or treatment
Its supportive care
ARDS considerations
- ICU care
- Resp modalities, nebulizer therapy, Chest physio, intubation and mechanical intubation Suctioning (PRN) bronchoscopy
- Frequent repositioning, prone is great
- Use of specialty beds
- Assess and intervene with pt anxiety to decrease o2 consumption (Calm them down)
Mechanical ventilation
- Pressure controlled device that maintains vent and o2 delivery
- Supports the process of gas exchange (Alveolar vent and art oxygenation)
- Invasive positive pressure, ET or trach
Non invasive mechanical ventilation
CPAP and BiPAP
Endotracheal tube intubation: indication
- Anesthesia purposes during surgery
- Inability to protect airway
- Altered mental status (Head injury/ drugs)
- Anticipated airway obstruction(Facial burns, epiglottitis, major facial or oral trauma)
- Apnea
- Ineffective clearance of secretions
- High risk of aspiration
- resp distress
- Planned post op short term vent
Reasons to intubate: Overview
- Taken into context with the situation
- Abnormal Abg
- Decreased PaO2, below 60
- Increased PaCO2
- Decreased PH
- Changes in LOC
- Diminished airway exchange
- Needs for increased o2 or vent despite use of supplemental O2 or NIPPV
- Used in cases of worsening resp failure
Cant protect their airway
Capnography
- Measuring the readings of CO2 in an ET tube for monitoring for placement and effectiveness
- used to diagnose early resp depression and airway disorders
ETT intubation considerations: Failure to protect airway
- Decreased LOC
- Impaired swallowing
- Airway obstruction
ETT intubation considerations: Is the patient a candidate for noninvasive positive pressure ventilation (NIPPV)
- Exacerbation of COPD
- Acute cardiogenic pulmonary edema
ETT intubation considerations: Is there a failure to oxygenationate or ventilate
- Oxy: PaO2<60 mmHg and low or normal CO2
- Ventilation: acidosis with PaCO2
Vent settings: Assist control (AC)
Does all the breathing for the pt
Vent settings: Synchronized intermittent (SIMV)
Patient has the drive to breath, so the vent acts as supplementary assistance to them
Vt Tidal volume
4-1ml/Kg
Vent settings
- Mode (AC or SIMV)
- Tidal volume (Vt)
- FiO2)
- PEEP (5-10 cmH20)
- RR
Causes of low pressure alarms
- Vent tubing disconnection
- Airway cuff leak or displacement
Nursing actions: Vent, low pressure alarm
- Assess pt and vent circuit
- Reconnect tubing
Always assess pt first
Causes of Vent high pressure alarms
Occurs when the pressure needed to vent the pt exceeds the present pressure limit
* Excessive secretions
* Biting the ET tube, Kink in the line
* Coughing, sneezing, gagging , attempting to talk
* Pulmonary edema, bronchospasm, pneumothorax/hemothorax
* Increased airway resistance, decreased lung compliance
High pressure alarms: Nursing actions
- Correct the underlying cause
- Critically ill pts can quickly decompensate so make it fast
- May need more sedation if biting
safety for a pt on ETT ventilation
- Bag valve mask (BVM)
- Reintubation kit
- Suction set up
High pressure alarm can indicate need for this
Sedation vacation
- Done once a day for pts on vent
- Done to see how they are doing, neuro checks and resp drive
Nursing interventions Vent: Promoting gas exchange
Auscultate lung sounds
* T+P
* Suction PRN
* Pain control
* Observe for hypoxia
* Humidification, O2 is very dry
* Nebulization
Nursing interventions Vent: Prevent injury and infection
- Prevent accidental extubation, monitor cuff pressure every 8 hrs
- Sedation and reassurance, pain control, restraints
- Pressure prevention with securement device
- Oral hygiene with chlorhexidine
- OOB, ROM exercies (If able)
What do you inflate cuff Vent
20-25 mmHg
Nursing care: preventing complications of Vent
- Prevent skin breakdown around tube
- Note location of ETT marking at teeth, gums or nare, this is the reference point in future assessments to make sure tube isn’t moving
- Assess for airway injury and or displacement of the tube
- Prevent ventilator associated events (VAE), pneumonia is common
- Communicate with pt who are awake, this may be accomplished with the use of a communication board or writing notes
Nursing care: preventing complications of Vent, Barotrauma and pneumothorax
Note PEEP, 5-10 mm H20
Nursing care: preventing complications of Vent: Delirium and post ICU syndrome
- Early extubation
- Early mobility
- Early family involvement
- Use of appropriate sedation
ABCDE bundle
- Awakening
- Breathing
- Coordination
- Delirium, monitoring and mgmt
- Early mobility
- Family engagement and empowerment
Used in vent pts
Ventilator acquired events (VAE) Prevention
- Elevate HOB 30+ degrees
- Routine oral care with chlorhexidine
- Weaning protocol: sedation vacations
- Prevent stress ulcers (Peptic ulcer prophylaxis) use a PPI
- VTE prophylaxis, SCD and pharmacotherapy
Vent weaning
- Process of withdrawing the pt from depending of the vent (Not everyone comes off vent)
- Physiologically and hemodynamically stable
- Spontaneous breathing , reversed resp failure
- Recovered from acute medical or surgical issues (Sepsis)
- Stable abg
- Interdisciplinary approach
- Vent mode: SIMV, patient has resp drive
- Mask: extubate within 2-3 hours after weaning, prob gunna need o2
- May need pulmonary rehab, Cough, deep breathing, turn and position, incentive spiro, gradual increase in activity
