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Med Surg: Acute Respiratory Distress Syndrome (ARDS)

Terms in this set (72)

ARDS
- sudden progressive form of acute respiratory failure
- alveolar capillary membrane becomes damaged and more permeable to intravascular fluid
- alveoli fill with fluid
- P/F ratio (PaO2/FiO2) over 400
Stages of Edema Formation in ARDS
1.) Normal alveolus and pulmonary capillary
2.) Interstitial edema occurs with increased flow of fluid into the interstitial space
3.) Alveolar edema occurs when fluid crosses the blood-gas barrier
What does ARDS cause?
- severe dyspnea
- hypoxia
- decreased lung compliance
- diffuse pulmonary infiltrates
Causes
direct or indirect lung injuries
What is the most common cause of ARDS?
sepsis
Three Phases of ARDS
1.) injury/exudative phase
2.) reparative or proliferative phase
3.) fibrotic phase
(1: Injury or Exudative Phase) What is this?
- 1-7 days after initial lung injury
- fluid crosses into alveolar space
- alveolar cells are damaged
- hyaline membranes line alveoli
- decreased gas exchange capability and lung compliance
- fluid in the sac
- severe V/Q mismatch
- unresponsive to increasing O2 concentrations
- lungs become less compliant
(1: Injury or Exudative Phase) Signs
- interstitial and alveolar edema and atelectasis
- fibrosis
- refractory hypoxemia (O2 levels decrease even though we are giving patients high amounts of oxygen)
- lungs become less compliant
(2: Reparative or Proliferative Phase) What is this?
- 1-2 weeks after initial lung injury
- body is trying to repair and reabsorb the fluids
- influx of neutrophils, monocytes, and lymphocytes
- fibroblast proliferation
- lung becomes dense and fibrous
(2: Reparative or Proliferative Phase) Signs
- lung compliance continues to decrease
- hypoxemia worsens
- thickened alveolar membrane (diffusion limitation and shunting)
- widespread fibrosis if it continues
- if phase is stopped, lesions will resolve
(3: Fibrotic Phase) What is this?
- poor prognosis
- 2-3 weeks after initial lung injury
- dead space in the lungs; scarring
- lung is completely remodeled by collagenous and fibrous tissues
(3: Fibrotic Phase) Signs
- scarring on lungs
- decreased lung compliance
- decreased area for gas exchange
- hypoxemia
- pulmonary hypertension (results from pulmonary vascular destruction and fibrosis)
Atelectasis
- fluid in the sac
- sac collapse
Early Clinical Manifestations
- dyspnea
- tachypnea
- cough
- restlessness
- chest auscultation may be normal or may reveal fine, scattered crackles
- respiratory alkalosis and mild hypoxemia caused by hyperventilation
- chest x-ray may be normal or reveal minimal scattered interstitial infiltrates
- edema may not show until 30% increase in fluid content in the lungs
Late Clinical Manifestations
- symptoms worsen with increased fluid accumulation and decreased lung compliance
- pulmonary function tests reveal decreased compliance, lung volumes, and functional residual capacity (FRC)
- tachycardia
- diaphoresis
- changes in mental status
- cyanosis
- pallor
- diffuse crackles and coarse crackles
- hypoxemia despite increased FiO2 (hallmark sign)
- increasing WOB despite initial findings of normal PaO2 or SaO2
Treatment
severe: endotracheal intubation and PPV
Whiteout/White Lung
- consolidation and widespread infiltrates throughout lungs
- leaves few recognizable air spaces
- pleural effusion may be present
What may develop if no therapeutic interventions are done?
- severe hypoxemia
- hypercapnia
- metabolic acidosis
- organ dysfunction
Nursing Assessment
Same as acute respiratory failure
Use of O2 inhalers, nebulizers, OTC drugs, immunosuppressant therapy
Previous intubation
Thoracic and abdominal surgery
Weight gain/loss
Fatigue
Dizziness
Dyspnea, wheezing, cough, sputum
Changes in sleep pattern, use of CPAP
Tachycardia progressing to bradycardia
Hypertension progressing to hypotension
Changes in pH, PaCO2, PaO2, SaO2
Abnormal central venous or pulmonary artery pressures
Headache
Chest pain or tightness
Anxiety, restlessness, agitation, confusion
Pale, cool, clammy or warm, flushed skin
Peripheral edema or cyanosis
Shallow, increasing respiratory rate progressing to decreased rate
Use of accessory muscles
Asymmetric chest expansion
Abnormal breath sounds
Pulsus paradoxus, JVD, pedal edema
Abdominal distention, ascites
Nursing Diagnoses
Ineffective airway clearance
Ineffective breathing pattern
Risk for imbalance fluid volume
Anxiety
Impaired gas exchange
Imbalanced nutrition: less than body requirements
Goals Following Recovery
- PaO2 within normal limits for age or at baseline on room air (greater than or equal to 60)
- normal pH
- SaO2 > 90%
- resolution of precipitating factor(s) for ARDS
- clear lungs on auscultation
What is the primary goal for respiratory therapy?
correct hypoxemia
Respiratory Therapy for modest-severe ARDS + refractory hypoxemia
intubation with mechanical ventilator
(Ventilator Settings) Rate
the number of mechanical breaths per minute the ventilator is set to deliver
(Ventilator Settings) Tidal Volume
the amount of air moving in and out of the lung with each normal breath
(Ventilator Settings) Peep
- the continuous distending pressure transmitted throughout the respiratory cycle
- is it the amount of pressure maintained in the airways at the end of exhalation
- higher levels needed for patients with ARDS
(Ventilator Settings) FiO2
- fraction of inspired oxygen
- room air is 21%, can deliver up to 100%
(Ventilator Settings) PIP
- peak inspiratory pressure
- the maximum pressure measured during inspiration
(Ventilator Settings) Minute Ventilation
the amount of air moved (inhaled or exhaled) by the patient over 60 seconds
(Ventilator Settings) Positive Pressure Ventilation
PEEP at 5 cm H2O compensates for loss of glottic function
Opens collapsed alveoli

Apply PEEP at 3-5 cm H2O increments

Higher levels of PEEP may be used in patients with ARDS

Can compromise venous return to right side of heart
Decreases preload, CO2, and BP

Higher levels of PEEP
Can hyperinflate alveoli
Can result in barotrauma or volutrauma

Normal PEEP: 5
Patients with ARDS should have higher than 5 to keep alveoli open
(Ventilator Modes) Assist Control (AC)
- each breath is either an assisted breath or a controlled breath
- delivers a constant tidal volume and a set rate
- patient can initiate own breath
(Ventilator Modes) Synchronized Intermittent Mandatory Ventilation (SIMV)
- syncs with patients breathing pattern
- used for weaning
- guarantees certain number of breaths
(Ventilator Modes) Pressure Support Ventilation
- each breath is supported by ventilator during inhalation
- patient regulates own respiratory rate and tidal volume
- used for weaning
Respiratory Therapy - Position Strategies
- turn from supine to prone position
May be sufficient to reduce inspired O2 or PEEP.
Prone position - for patients with refractory hypoxemia
Increases oxygen levels without having to give them oxygen.
When in supine position mediastinal and heart contents place more pressure on lungs than when in prone.
Predisposes patient to atelectasis
Fluid pools in dependent regions of lung
Continuous Lateral Rotation Therapy (CLRT)
- continuous, slow side-to-side turning < 40 degrees
- 18 of every 24 hours
Kinetic Therapy
patient rotated side-to-side > 40 degrees
Rotoprone Bed
- allows clinicians to place patients in the prone position, safely and effectively
- this product is not specifically indicated for the treatment of ARDS or VAP
Mechanical Ventilation: Role of RN
Develop plan for communication
Provide emotional support
Sedatives, analgesics, paralytics PRN
Auscultate and assess for decreased ventilation and adventitious breath sounds
Monitor ventilator settings and alarms start of shift/hourly
Alarms on
Suction PRN
Reposition and secure ET tube
Monitor oxygenation levels and signs of respiratory fatigue when weaning
Monitor nutrition, skin integrity, GI
Ambu bag at bedside
Change ventilator tubing
Assess for kinks, leaks
Hemodynamic Monitoring
- via a central venous or pulmonary artery catheter
- monitor CO and BP
- sample blood for ABGs
Inotropic Drugs
- dobutamine
- dopamine
(Dobutamine) Names
Dobutrex
(Dobutamine) Route
IV
(Dobutamine) When is a lower dose given?
heart failure
(Dobutamine) Onset
1-10 minutes
(Dobutamine) Peak
10-20 minutes
(Dobutamine) Assessment
monitor:
- BP
- ECG
- HR
- MAP
- glucose
- renal function
- urine output
(Dopamine) Names
Intropin
(Dopamine) Route
IV
(Dopamine) Onset
within 5 minutes
(Dopamine) Duration
< 10 minutes
(Dopamine) What is common with dopamine?
extravasation
(Dopamine) Extravasation Antidote
phentolamine
Complications of Treatment
- VAP
- barotrauma
- volutrauma
- high risk for stress ulcers
- renal failure
(VAP) What is this?
ventilator-associated pneumonia
(VAP) Prevention Strategies
- hand washing
- oral care
- elevate HOB 30-45 degrees
- daily "sedation holidays"
- venous thromboembolism prophylaxis
- daily oral care with chlorhexidine
(VAP) Symptoms
- fever
- elevated WBC count
- purulent or odorous sputum
- crackles or wheezes
- pulmonary infiltrates
(Barotrauma) What is this?
- rupture of overdistended alveoli during mechanical ventilation
- air can escape into pleural space from alveoli or interstitium, accumulate, and become trapped
- lung collapse (pneumothorax)
(Barotrauma) Treatment
chest tube
(Barotrauma) Who is at an increased risk?
- COPD
- ARDS
(Barotrauma) What can it cause?
subcutaneous emphysema
(Volutrauma) What is this?
- occurs when large tidal volumes are used to ventilate noncompliant lungs
- alveolar fracture and movement of fluids and proteins into alveolar spaces
- smaller tidal volumes or pressure-control ventilation is now standard in ARDS
(Stress Ulcers) How common are stress ulcers in patients with ARDS on mechanical ventilation?
30%
(Stress Ulcers) Management Strategies
- correction of predisposing conditions
- prophylactic antiulcer drugs
- early initiation of enteral nutrition
(Stress Ulcers) What drug is used as prophylaxis?
Pantoprazole (Protonix)
(Stress Ulcers) Pantoprazole Class
PPI
(Stress Ulcers) Pantoprazole Route
- IV
- PO
(Stress Ulcers) Pantoprazole PO
give 30-60 minutes before a meal
(Stress Ulcers) Pantoprazole Onset
- PO: 2.5 hours
- IV: 15-30 minutes
(Stress Ulcers) Pantoprazole Peak
2 hours
(Stress Ulcers) Pantoprazole Duration
24 hours
(Renal Failure) What may cause it?
- hypotension
- hypoxia
- hypercapnia
- occurs from decreased renal perfusion and subsequent decreased delivery of O2 to kidneys
- nephrotoxic drugs used to treat ARDS-related infections
Evaluation
No abnormal breath sounds
Effective cough and expectoration
Normal respiratory rate, rhythm, and depth
Synchronous thoracoabdominal movement
Appropriate use of accessory muscles
Decreased or absent peripheral edema
PaO2 and PaCO2 within normal ranges or at baseline
Maintenance of weight or weight gain
Serum albumin and protein within normal ranges
Normal pulmonary artery or pulmonary artery wedge pressures
Decreased anxiety
Verbalization of positive attitude toward outcome
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