What is ARDS?
Acute respiratory distress syndrome
What are the features of acute respiratory distress syndrome?
-persisting hypoxia -decreased pulmonary compliance -dyspnea -noncardiac-associated bilateral pulmonary edema -dense pulmonary infiltrates seen on x-ray
What are the causes of lung injury in acute respiratory distress syndrome?
-systemic inflammatory response is common pathway (trigger) -alveolar-capillary membrane injured (main site)
What are the intrinsic causes of alveolar-capillary membrane injured?
-sepsis -shock
What are the extrinsic causes of alveolar-capillary membrane injured?
-aspiration -inhalation injury
What is ALI?
Acute lung injury
What diagnostic assessments of acute respiratory distress syndrome?
-lower PaO2 value on ABG -refractory hypoxemia -"white-out" (ground glass) appearance to chest x-ray -no cardiac involvement on ECG -low-to-normal PCWP
What is PCWP?
Pulmonary capillary wedge pressure
What causes refractory hypoxemia?
Not responding to high concentration of O2
What does case management focus on?
Phases of acute respiratory distress syndrome
Classic signs of acute respiratory distress syndrome?
-SaO2 below 90% (persistently) -PaO2 less than 60mmHg (normal 80-100) -pH less than 7.30 (acidy) -CO2 greater than 50mmHg (happens in stage 4)
What are the stages of acute respiratory distress syndrome?
-early stages -late stages
What are the symptoms in stage 1 acute respiratory distress syndrome?
-dyspnea -tachycardia
What occurs during the early stages of acute respiratory distress syndrome?
Fluid in interstitial spaces
What occurs during stage 2 acute respiratory distress syndrome?
Patchy infiltrate form from increased pulmonary edema
What is the goal in stage 2 acute respiratory distress syndrome?
-mechanical ventilation to prevent complications
What occurs during stage 3 acute respiratory distress syndrome?
Increased hypoxemia -responds poorly to high levels of oxygen (deliver oxygen and prevent complications)
What occurs during stage 4 acute respiratory distress syndrome?
Irreversible -prevent sepsis, pneumonia, MODS, patient from ventilator
What is included in the late stages of acute respiratory distress syndrome?
Stages 2-3
What occurs during the late stages of acute respiratory distress syndrome?
Fluid shifts into the alveoli (wet alveoli - crackles in lungs)
What occurs in the next ten days of acute respiratory distress syndrome?
Pulmonary fibrosis (like you have burned your lungs)
What happens to patients in stage 3 and stage 4 acute respiratory distress syndrome?
They have chronic "burned" lungs -may lead to an entire systemic inflammation (also called SIRS) -fluids will shift from outside (interstitial spaces) of the lungs to the inside of the lungs -can lead to multiple organ dysfunction syndrome (MODS)
Classic signs of acute respiratory distress syndrome?
-SaO2 below 90% (persistently) -PaO2 less than 60mmHg (normal 80-100) -pH less than 7.30 (acidy) -CO2 greater than 50mmHg (happens in stage 4)
What interventions are appropriate for a patient with acute respiratory distress syndrome?
-ET intubation, conventional mechanical ventilation with PEEP or CPAP -drug and fluid therapy -nutrition therapy -case management
What are the types of intubation?
-endotracheal intubation -nasotracheal intubation -tracheal intubation
What is the function of surfactant?
Lubricates and decreases surface tension
What is PEEP?
Positive end-expiratory pressure
What is CPAP?
Continuous positive airway pressure
What medications are given to a patient with acute respiratory distress syndrome?
-corticosteroids -antibiotics -IV fluids with diuretics
What do corticosteroids cause in patients with acute respiratory distress syndrome?
-decreased WBC -decreased inflammation -stabilize capillary membranes
What do conservative fluid therapy with smaller amounts of IV fluids and diuretics cause in a patient with acute respiratory distress syndrome?
Maintain fluid balance
What does malnutrition cause in a patient with acute respiratory distress syndrome?
-reduced respiratory muscle function -reduced immune response
What is done to treat malnutrition in a patient with acute respiratory distress syndrome?
-dietitian consult -enteral nutrition (tube feed) -parenteral nutrition (TPN)
When are endotracheal tubes used?
Short-term -less than 14 days
What happens if someone has to be intubated for longer than 14 days?
Tracheostomy
What is the reason for a tracheostomy after 14 days?
Reduce tracheal and vocal cord damage
How do you verify endotracheal tube placement?
-end-tidal carbon dioxide levels -chest x-ray -assess for breath sounds bilaterally, symmetrical chest movement, air emerging from ET tube
What can taping the tube too tightly to the nose cause?
Skin breakdown on the nares
What nursing care is included for endotracheal tubes?
-assess tube placement, minimal cuff leak, breath sounds, chest wall movement -prevent movement of tube by patient -check pilot balloon -soft wrist restraints -mechanical sedation
What medication is used for endotracheal tube placement?
Versed
What types of mechanical ventilation are there?
-negative-pressure -positive-pressure
What is positive-pressure mechanical ventilation?
During inspiration, pressure is generated that pushes air into the lungs and expands the chest
How are positive-pressure ventilators classified?
By the mechanism that ends inspiration and starts expiration
What three major ways is inspiration cycled in positive-pressure ventilators?
-pressure-cycled -time-cycled -volume-cycled
What is the function of a pressure-cycled ventilator?
-push air into the lungs until a preset airway pressure is reached -tidal volumes and inspiratory time vary - used for short periods
What is a modern form of pressure-cycled ventilator?
Bi-PAP (bi-level positive airway pressure)
What is the function of a time-cycled ventilator?
-push air into the lungs until a preset time has elapsed -tidal volume and pressure vary, depending on needs of the patient and type of ventilator
What is the function of a volume-cycled ventilator?
-push air into the lungs until a preset volume is delivered - a constant tidal volume is delivered regardless of the pressure needed to deliver the tidal volume -set pressure limit prevents excessive pressure from being exerted on the lungs
What are the modes of ventilation?
-assist-control ventilation (AC) -synchronized intermittent mandatory ventilation (SIMV) -Bi-level positive airway pressure (Bi-PAP)
What is assist-control ventilation?
-often as a resting mode, takes over the work of breathing for the patient - tidal volume and ventilator rate are preset
What is a disadvantage of assist-control ventilation?
Ventilator continues to deliver a preset tidal volume even with patient's spontaneous breathing rate increases - can cause hyperventilation and respiratory alkalosis
What is synchronized intermittent mandatory ventilation?
Tidal volume and ventilator rate are preset -allows spontaneous breathing -can be used as a main ventilator mode or as a weaning mode
What is the weaning mode of a synchronized intermittent mandatory ventilation system?
Number of mechanical breaths is gradually decreased and the patient gradually resumes spontaneous breathing
What is bi-level positive airway pressure?
Provides noninvasive pressure support ventilation by nasal mask for facemask
What type of patients would use a bi-level positive airway pressure?
Patient with sleep apnea
What are the ventilator controls and settings?
-tidal volume -rate in breaths/min -fraction of inspired oxygen (FiO2) -PIP -CPAP -PEEP -flow rate
What is the tidal volume on the ventilator?
The volume of air the patient receives with each breath, as measured on either inspiration or expiration
What is the setting prescribed of tidal volume (VT)?
7-10mL/kg of body weight -adding 0 to the patient's weight in kilograms gives an estimate of tidal volume
What is the rate or breaths per minute on the ventilator?
Number of ventilator breaths delivered per minute
What is the setting prescribed of rates per minute?
10-14 breaths/minute
What is the rate or fraction of inspired oxygen (FiO2) on the ventilator?
Oxygen level delivered to the patient
What is the setting prescribed of fraction of inspired oxygen (FiO2)?
Based on ABG values and the patient's condition - range is 21-100% oxygen, which is warmed and humidified
Why is the oxygen warmed and humidified?
Prevent mucosal damage
What is PIP?
Peak airway (inspiratory) pressure
What is peak airway pressure?
-pressure used by the ventilator to deliver a set tidal volume at a given lung compliance -highest pressure reached during inspiration
What does an increased PIP reading mean?
Increased airway resistance in patient or ventilator tubing, increased secretions -pulmonary edema -decreased pulmonary compliance
What is CPAP?
Continuous positive airway pressure
What is continuous positive airway pressure?
Applies positive airway pressure throughout the entire respiratory cycle for spontaneously breathing patients
What is the purpose of continuous positive airway pressure?
-keeps the alveoli open during inspiration -prevents alveolar collapse during expiration -increases functional residual capacity (FRC) -improves oxygenation
What is the normal prescribed CPAP level?
5-15cm H2O to promote adequate oxygenation
What is PEEP?
Positive end-expiratory pressure
What is positive end-expiratory pressure?
Positive pressure exerted during expiration
What is the purpose of positive end-expiratory pressure?
Improves oxygenation by enhancing gas exchange -preventing atelectasis
When is positive end-expiratory pressure used?
-arterial oxygen pressure (PaO2) remains low with a FiO2 of 50-70% or greater
What is the normal prescribed PEEP level?
-5-15cm H2O to promote adequate oxygenation -monitored on the peak airway pressure dial
What is an important warning about positive end-expiratory pressure?
Lower the FiO2 delivered whenever possible because prolonged use of a high FiO2 can damage lungs from the toxic effects of oxygen
What is flow rate?
How fast each breath is delivered
What is the normal prescribed flow rate?
40L/min
What are other settings that may be used depending on the type of ventilator and mode of ventilation?
-inspiratory and expiratory cycle -waveform -expiratory resistance -plateau
What nursing management is used with patients on a ventilator?
-always assess the patient first, ventilator second -monitor patient response -manage ventilator system -prevent complications
What cardiac complications can occur with ventilator systems?
-hypotension -fluid retention -Valsalva maneuver
What is Valsalva maneuver?
A form of vagal stimulation of the cardiac conduction system in which the health care provider instructs the patient to bear down as if straining to have a bowel movement
What is a hallmark sign of recovery for a patient with acute respiratory distress syndrome?
Diuresis
What other type of complications can occur with ventilator systems?
-GI -nutritional -infections -muscle deconditioning -ventilator dependence
What is VAP?
Ventilator assisted pneumonia
What is the most common organism involved in ventilator assisted pneumonia?
Pseudomonas
What respiratory complications that can occur with intubation?
-barotrauma -volutrauma
What is barotrauma?
Damage to lungs by positive pressure
What is a common finding with barotrauma?
-air in the neck -pneumothorax -subcutaneous emphysema -pneumomediastinum
What is volutrauma?
Damage to the lungs by excess volume delivered to one long or the other
What is extubation?
Removal of the endotracheal tube
What does the nurse need to do for extubation?
-hyperoxygenate patient -thoroughly suction ET and oral cavity -rapidly deflate ET cuff -remove tube at peak inspiration -instruct patient to cough -monitor patient every 5 minutes; assess ventilatory pattern for respiratory distress