T3: Respiratory Failure & ARDs Flashcards
Causes of ARDS
sepsis (infection), pneumonia, status asthmaticus
what is one of the first things people present with in respiratory failure
altered level of consciousness
hypoxemia
insufficient oxygen transferred to the blood
how is hypoxemia reflected in ABGs
Decreased PaO2 and SaO2
hypercapnia
inadequate CO2 removal
how is hypercapnia reflected in ABGs
Increased PaCO2
PaO2 level in hypoxemic patient
<60mmHg
PaCO2 level in hypercapnic patient
> 50mmHg
most common physiologic mechanisms of hypoxemic respiratory failure
-v/q mismatch
-shunting
-diffusion limitation
-alveolar hypoventilation
V/Q mismatch
An imbalance in the amount of oxygen received in the alveoli and the amount of blood flowing through the alveolar capillaries
shunting
through heart bypassing lungs OR through lungs without gas exchange
diffusion limitation
Gas exchange across alveolar-capillary membrane is compromised, exchange of CO2 and O2 cannot occur because of the thickened alveolar-capillary membrane
increased lactic acid. from hypoxemia can cause
metabolic acidosis
respiratory manifestations of hypoxemia
-dyspnea, tachypnea, prolonged expiration
-nasal flaring
-intercostal muscle retraction
-use of accessory muscles
-decreased SpO2 (less than 80%)
-paradoxic chest or abdominal wall movement with respiratory cycle (late)
-cyanosis (late)
CNS clinical manifestations of hypoxemia
agitation; confusion; disorientation; restless, combative behavior; delirium; decreased level of consciousness; coma (late)
CV clinical manifestations of hypoxemia
tachycardia; hypertension; skin cool, clammy, and diaphoretic; dysrhythmias (late); hypotension (late)
Consequences of hypercapnia
-Slow changes allow CO2 allow compensation
-Arterial pH able to adjust
-Treat primary cause or patient’s condition will deteriorate
Conditions causing impaired ventilation (hypercapnia)
-CNS problems
-neuromuscular conditions
-chest wall abnormalities
-conditions affecting the airway and/or alveoli
respiratory clinical manifestations of hypercapnia
-dyspnea
-tripod position
-pursed-lip breathing
-decreased RR or rapid rate with shallow respirations
-decreased tidal volume
-decreased minute ventilation
CNS clinical manifestations of hypercapnia
-morning headache
-disorientation, confusion
-progressive somnolence
-increased intracranial pressure
-coma (late)
CV clinical manifestations of hypercapnia
tachycardia, HTN, dysrhythmias, bounding pulse
neuromuscular clinical manifestations of hypercapnia
muscle weakness, decreased deep tendon reflexes, Tremors, seizures (late)
decreased O2 manifestations
restlessness, confusion, agitation
increased CO2 manifestations
morning headache, decreased RR, and decreased LOC
early signs of compensation of the heart and lungs
Tachycardia, tachypnea, and mild HTN
Late signs of inadequate compensation
-Cyanosis (unreliable indicator)
-PaO2 less than or equal to 45 mm Hg
position for acute respiratory failure
sit upright/tripod
keep HOB up
Work of breathing (WOB);
respiratory muscles effort needed to inhale/exhale
what is a red flag in acute respiratory failure
Change from rapid to slow RR à severe muscle fatigue IMPENDING respiratory arrest
how does morphine help with work of breathing (WOB)
it dilates the coronary artery so the heart is getting more blood supply which decreases the workload of breathing
observation for acute respiratory failure
-Ability to speak à full or partial sentences, 2 to 3 word dyspnea
-Pursed-lip breathing Increased expiratory time; prevents small bronchial collapse
-Retraction of intercostal spaces or supraclavicular area
-use of accessory muscles
-Paradoxical breathing
-diaphoresis
breath sounds in ARF
fine or coarse crackles, absent (consolidation), pleural rub
prevention for ARF
Deep breathing and coughing, incentive spirometry, and early ambulation
goal of corticosteroids and bronchodilators
Reduce airway inflammation and bronchospasm
goal of IV diuretics, Morphine, and Nitroglycerine
relieve pulmonary congestion
goal of IV antibiotics
treat infections
goal of Benzodiazepines and Opioids
Reduce anxiety, pain, and restlessness
interventions to Mobilization Secretions
-Patient positioning- HOB 30, Side lying if Aspiration risk,
-huff coughing
-Chest physiotherapy-
-Suctioning
-Humidification- Thins secretions
-Hydration- 2-3 L/day, IV fluids (check for overload)
huff coughing
Inhale deeply while leaning forward
Exhale sharply with a “huff” sound to help keep airways open while mobilizing secretions
complications of suctioning
hypoxia, Hi ICP, Low BP, HTN, PVCs/Tachy/Bradycardia
Positive pressure ventilation (PPV)
The provision of air under pressure by a mechanical respirator, a machine designed to improve the exchange of air between the lungs and the atmosphere.
Noninvasive PPV must have…
spontaneous breathing, must be awake alert and have stable VS
what are the two forms of positive pressure ventilation (PPV)
CPAP and BiPAP
CPAP
continuous positive airway pressure
BiPAP
bilevel positive airway pressure
acute respiratory distress syndrome (ARDS)
a sudden and progressive form of acute respiratory failure in which the alveolar-capillary membrane becomes damaged and more permeable to intravascular fluid.
What causes ARDS?
most common- sepsis
direct lung injury
indirect lung injury
initial clinical manifestations of ARDS
Mild dyspnea, tachypnea, cough, restlessness
-Chest auscultation may be normal or may reveal fine, scattered crackles
-ABGs: Mild hypoxemia and respiratory alkalosis from hyperventilation
¡Chest x-ray : minimal interstitial infiltrates, progresses till lungs appear “whited out
later signs of ARDS
-increased WOB
-tachypnea and intercostal reatration
-tachycardia, diaphoresis, changes in mental status, cyanosis, pallor
-diffuse or coarse crackles with expiration
-whiteout inflitrate on xray
-REFRACORY HYPOXEMIA despite 100% FiO2
-hypercapnia
what drugs are given with cardiac involvement of ARDS
-Norepinephrine
-Dopamine
-Dobutamine
¡Strategies for prevention of VAP
-Good hand hygiene
-Elevate HOB 30 to 45 degrees
-Daily oral care with chlorhexidine (0.12%) solution
-Daily assessment for readiness for extubation
-Stress ulcer prophylaxis
-Venous thromboembolism prophylaxis
Positive end expiratory pressure (PEEP)
increased functional capacity; helps keep open/collapsed alveoli
