Pulmonary Disorders Flashcards
What is Acute Respiratory failure (ARF)?
Inadequate gas exchange marked by HYPOXEMIA (low O2 in blood)
What are the three main causes of ARF?
Intrapulmonary shunting
V/Q mismatch
Alveolar hypoventilation
S/S of ARF
Tachycardia, tachypnea, use of accessory muscles, nasal flaring, grunting
-any pt who exhibits confusion, agitation or restlessness must be assessed for HYPOXEMIA FIRST
PaO2 <60 / SaO2 <90% OR paCO2 >50 with acidosis (low pH)
Management of ARF
Supplemental O2 therapy- goal is SaO2 >90%
- supplemental O2 effective with alveolar hypoventilation or V/Q mismatch but NOT in shunt
-Intrapulmonary shunt requires positive pressure (CPAP, BiPAP, or Ventilator)
Alveolar hypoventilation, causes, and interventions
Same as Resp. Acidosis with hypoxemia
Causes:
- anything that limits ventilation (neuro trauma, pneumothorax, lung trauma, oversedation, pain)
Interventions:
- optimize ventilation (positioning, pain relief, secretion removal, correct underlying cause)
-if on ventilator, increase rate and/or tidal volume to breathe off CO2
PaCO2 is a direct reflection of alveolar hypoventilation
How does patient positioning affect ventilation (V) and perfusion (Q)?
When sitting upright,
- upper zone of the lungs has more ventilation and less perfusion (V>Q)
-middle zone has equal ventilation and perfusion
-lower zone has more perfusion than ventilation
More perfusion will go to the alveoli that are closer to the ground (affected by gravity)
When laying down, the weight of the heart and diaphragm compress the dependent alveoli and secretions pool in posterior lungs where perfusion is higher
-why we prone
What are the benefits of heated and humidified air?
Heated and humidified O2:
- decrease airway inflammation
- maintain mucociliary function
-increase mucous clearance
- reduce caloric expenditure (decrease work on lungs)
What is the benefit for the patient when using a high-flow rate?
-increases FiO2
- decreases dead space
- provides low level positive pressure (PEEP)
- decreases the work of breathing
What are the benefits of using a High-flow nasal cannula (HFNC)?
- reduces the need for intubation
- decreases the work of breathing
- provides a low level of positive pressure
What is proning and why is it used?
Proning positions the patient on their stomach in a “swimmer” position or places them with their good lung down to improve expansion in the bad lung
—improved V/Q matching
Reduces alveolar compression by the heart and diaphragm, allowing for better expansion of the dorsal lung, more surface area = alveolar recruitment
Nursing management for ARF
-positioning that is optimal for oxygenation
-pulmonary exercises
—deep breath hold 3 seconds; IS
—no dry coughing
-hydrate and suction secretions
-increase movement when possible
-don’t cluster care to allow for rest
Medications for ARF
Medication treatment depends on the cause of the respiratory failure and the patient’s condition
-steroids
-sedation
-neuromuscular blockers
-analgesia
What is pneumonia?
Acute inflammation of the lung parenchyma caused by an infectious agent
-often related to dental plaque and aspiration of plaque organisms
—BASIC MOUTH CARE is so important
HAP= hospital acquired pneumonia
-occurs after 48 hours in the hospital
Pneumonia management
-O2 therapy (non-invasive but mechanical ventilation if necessary)
-nursing same as ARF
-Drugs including antibiotics and bronchodilators
What happens when a patient aspirates acid?
-bronchospasm and atelectasis
-may cause an inflammatory response with severe hypoxemia, V/Q mismatch, and shunt
- frequently progresses into ARDS
If aspirated high pH gastric contents, bacterial pneumonia may develop
**patients with aspiration are at high risk of developing ARDS
Management of aspiration
-supportive care first
-O2 therapy
-Nursing: HOB up, good lung down, deep breathing, IS
-possible bronchoscopy
NO steroids
Antibiotics after 48 hours
Best practices for preventing aspiration in adults
- maintain HOB 30-45 degrees
- use sedatives sparingly
- maintain endotracheal cuff pressures at an appropriate level
What is acute respiratory distress syndrome (ARDS)?
Inflammatory syndrome marked by:
- disruption of the alveolar-capillary membrane
- non-Cardiogenic pulmonary edema
In ARDS, the alveolar-capillary membrane leaks fluid out of capillaries and into the alveolar space AND alveoli leaks into the interstitial space
—causes ‘junk’ in the alveoli
—CO2 is smaller so it can still pass through, but O2 is larger and has a harder time entering the capillary
THEREFORE, O2 is a more sensitive indicator of ARDS
What are the causes and major risk factors for ARDS?
May be caused by direct injury to pulmonary epithelium or secondary to non-pulmonary insult
- sepsis (non-pulm.)
-aspiration (pulm. Or non-pulm.)
- pneumonia (non-pulm.)
- trauma (pulm.)
What clinical symptoms would you expect to see with ARDS?
Persistent hypoxemia despite supplemental oxygen
Diagnostic criteria: P/F ratio < 300
Care for ARDS
Most effective treatment is supportive care
Ventilator
-maintain pH 7.2 or higher
Proning
-at least 16 hours/day to improve V/Q matching and alveolar recruitment
Maintain C.O.
-but keep the patient dry (adequate preload but not high)
Outcomes for ARDS
Mortality about 40%
Pulmonary fibrosis is common afterwards
Potential for permanent neurologic impairment with impaired quality of life
Communicate that recovery will take time and there will be residual pulmonary damage
