Respiratory Failure Flashcards
What is the function of the respiratory system?
To facilitate gas exchange (oxygen and carbon dioxide)
What happens without adequate gas exchange?
Metabolic needs of the body are not met and tissue/organ failure will occurr
What does management of patients with acute respiratory illnesses focus on?
- improving oxygenation and ventilation
- treating the underlying cause
- reducing anxiety
- preventing complications
What is respiratory failure?
The state in which one or both gas exchanging functions are inadequate (insufficient amount of oxygen for transfer to the cells or insufficient removal of carbon dioxide)
Is respiratory failure a condition or a disease?
A condition
What are some disease processes associated with respiratory failure?
- pneumonia
- COPD
What is respiratory failure classified as?
- hypoxemia
- hypercapnic
What is hypoxemia?
- low levels of oxygen within the blood
- pulse oximetry < 90%
- PaO2 < 60mmHg
- oxygen failure (inadequate oxygen transfer between alveoli and capillary bed)
- ex: pneumonia, pulmonary emboli, toxic inhalation (smoke), poor cardiac output (heart failure)
What is hypercapnia?
- excessive amounts of CO2 in the blood (cant ventilate properly)
- measured using pulse oximetry and arterial blood gases
- PaCO2 > 45 mmHg
- ventilatory failure (CO2 retention)
- ex: trauma, neuromuscular disease, sedation (CNS), COPD
What is ventilation - perfusion mismatch a cause of?
Hypoxemia
What is ventilation - perfusion mismatch?
- not enough air entering the lungs (poor ventilation)
- insufficient blood supply, cannot carry enough oxygen to the cells (poor perfusion)
- ex: pulmonary embolus, asthma, COPD
What is shunting a cause of?
Hypoxemia
What is shunting?
- blood exists in the heart but has not been involved in gas exchange
- blood did not go to the lungs and less/low oxygenated blood is transferred into the vascular system
- can be due to structural heart abnormalities ( atrial septal defect, ventricular septal defect)
What is diffusion limitation a cause of?
Hypoxemia
What is diffusion limitation?
- decrease in gas exchange across the alveolar - capillary membrane due to process that thicken or destroy the membrane
- results in poor gas exchange; occurs more often during exercise than rest
- ex; emphysema, pulmonary fibrosis
What is alveolar hypoventilation a cause of?
Hypoxemia
What is alveolar hypoventilation?
- a decrease in ventilation that results in an increase in carbon dioxide levels and a subsequent decrease in oxygenation levels
- causes: chest wall dysfunction, restrictive lung disease, neuro-muscular disease (Guillain-Barre syndrome, Myasthenia Gravid)
What does hypercapnia lead to?
Acid-base imbalance
What are some causes of hypercapnia?
- trauma; rib fractures
- medications that depress CNS (depressants, anaesthetics)
- neuro-muscular disease; cystic fibrosis, Myasthenia gravis
What happens when respiratory failure occurs in the airways and alveoli?
- fluid enters the lungs and interferes with gas exchange
- bronchospasm reduces airflow
- alveoli destroyed by infection or enzyme imbalance
- secretions that are extremely viscous obstructing gas exchange
What happens when the respiratory failure occurs in the central nervous system?
- respirations are decreased by opioids or CNS depressants
- brainstem injury (ANS)
What happens when respiratory failure occurs in the chest wall?
- soft tissue injury (ribs)
- kyphoscoliosis
- morbid obesity
What happens when respiratory failure occurs due to neuromuscular conditions?
- spinal cord injury (cervical)
- phrenic nerve injury (impairs diaphragm)
- muscle weakness or paralysis
- muscular dystrophy, myasthenia gravis
What is tissue oxygen delivery determined by?
The amount of oxygen carried by hemoglobin
Respiratory failure can increase problems for patients with ____?
- anemia
- cardiac problems
What needs to be assessed for tissue oxygen delivery?
- cardiac status (heart rate and rhythm)
- blood counts (RBS’s, Hgb, and Hct)
- peripheral extremities (pallor, coolness, and cyanosis)
What is an example of acute or rapid onset or respiratory failure?
- patient with asthma experiences an exacerbation
- bronchospasm and a marked decrease in airflow
What is an example of gradual onset respiratory failure?
- patient with COPD who develops a respiratory infection
- worsening their condition
What is an early sign in respiratory failure?
- change in patients mental status
What are some late signs of respiratory failure?
- decreased LOC (lethargy)
- acidosis
- hypotension
- bradycardia and weak pulses
What is dyspnea?
- difficulty breathing
- some other things occur with it as well such as change in mental status, restlessness, confusion, agitation, tachycardia, mild hypertension, cool, pale, and clammy skin
What is tachypnea?
- rapid and or shallow breaths
- pulse oximetry (SpO2) <90%
What is hypoxia?
- the condition in which the partial pressure oxygen (PaO2) has fallen sufficiently to cause signs and symptoms of inadequate oxygenation
What can severe hypoxia lead to?
Anaerobic metabolism
What is the waste product of anaerobic metabolism?
Lactic acid
What does lactic acid need to be buffered with?
- bicarbonate
What causes acidosis?
- a build up of carbon dioxide and an increase in lactic acid production while using up bicarbonate stores
What does an acidotic blood pH significantly affect?
- heart rhythm
- renal and brain function
What are some diagnostic studies for respiratory failure?
- history and physical assessment
- chest x-ray
- arterial blood gas (ABG) analysis (PaO2 < 80mmHg and or CO2 > 45 mmHg, assess serum pH level)
- labs (CBC - RBC, H & H, sputum and or blood cultures, electrolytes)
- advanced diagnostic testing (V/Q lung scan, CT scan, ECG monitoring)
What health information should be obtained when assessing for respiratory failure?
- past medical history (lung disease, exposure to toxins, recent travel)
- medications (use of oxygen, bronchodilators, immune suppressants, corticosteroids)
- surgery (thoracic or abdominal)
- previous intubations
What information should be gathered in an objective assessment when assessing for respiratory failure?
- acute respiratory failure (exacerbation of current issue (COPD, pneumonia))
- tachypnea and or dyspnea
- shallow breathing
- does patient remain in an upright position (tripod position)
- difficulty speaking, only a few words between breaths
- late signs like retraction and cyanosis
- neurological (confusion, restlessness, agitation)
- cardiovascular (tachycardia, hypertension, mild edema)
- integumentary (pale, cool, and clammy skin, peripheral cyanosis)
What is a retraction?
The inward movement of intercostal muscles
What is cyanosis?
The blueing of the lips or fingertips
What are some nursing diagnoses for respiratory failure?
- impaired gas exchange
- ineffective airway clearance
- ineffective breathing pattern
What are some ways to prevent respiratory distress?
- deep breathing and coughing
- use of incentive spirometer
- ambulation as soon as possible
- head of bed elevated
- optimizing hydration and nutrition
Respiratory problems require ____ interventions?
Respiratory interventions
What is the number one thing to assess in terms of respiratory distress?
ABS’s
- airway
- breathing
- circulation
What are some oxygen respiratory therapies for respiratory failure?
- oxygen therapy to correct hypoxemia
- nasal cannula
- masks (simple, venturi, rebreather, and non-rebreather)
- BIPAP or CPAP machines
- intubation
What are the flow rates for each oxygen device?
- nasal cannula (2-4L/min)
- simple face mask (6-12L/min (35-50%))
- venturi mask (24-50% (more precise))
- partial rebreather mask (6-10L/min (40-60%))
- non-rebreather mask (60-90% (high flow))
- high flow cannula (up to 60L/mon (21-100%)
Do people with COPD need high or low flow oxygen?
Low
What can extended use of high flow oxygen cause?
Injury to the lungs
- toxic free radicals are metabolite of oxygen
- damage enzymes - surfactant
- increased microvascular permeability
What can retained secretions lead to?
- narrowing airways
- limiting of gas exchange
What is augmented coughing?
Nurse assisted to help force air out of the lungs
What is huff coughing?
A series of coughs saying the word huff which moves secretions upwards?
What are some respiratory techniques for mobilizing secretions?
- positioning
- elevating the head of the bed at least 45 degrees
- chest physiotherapy
- airway suctioning (yonkers - oral secretions, nasal tracheal suctioning)
When someone with lung secretions is lying down, which lung should be facing down?
The good lung should be facing down (allows secretions to drain out of good lung)
What is positive pressure ventilation?
- if the patient cant improve their ventilation or respiratory status
- non-invasive positive pressure treatments may be implemented (CPAP and BIPAP)
What is CPAP and what does is stand for?
Continuous positive airway pressure
- a constant level of pressure above atmospheric pressure is continuously applied to the upper airway
- the positive pressure is intended to prevent upper airway collapse or to reduce the work of breathing in conditions such as acute respiratory distress
- highly effective in managing obstructive sleep apnea
What is BIPAP and what does it stand for?
Bilevel positive airway pressure
- delivers higher pressure on inspiration and maintenance lower pressure on expiration
- keeps alveoli inflated, promoting gas exchange and increased exhalation of CO2
- nurses are required to assess respiratory status, monitor o2 sat, assess skin for breakdown under mask, ensure adequate nutrition and hydration, interventions to manage patients anxiety
What are some goals of medication therapy?
- relief of bronchospasms
- reduction of airway inflammation
- reduction of pulmonary congestion
- treatment of infection
- reduction of anxiety and restlessness
What medication should be used for relief of bronchospasms?
- bronchodilators
- binds to beta adrenergic receptors
- fenoterol hydrobromide, salbutamol, albuterol
What medication should be used for reduction in airway inflammation?
- corticosteroids
- supress inflammatory response
- methylprednisolone
What medication should be used for reduction in pulmonary secretions?
- diuretics
- reduces fluid volume in the vascular system
What medication should be used for pulmonary infections?
- start with a broad spectrum antibiotic
- culture the phlegm (target specific pathogen)
- excessive mucous - treatment with expectorant (gaifenesin)
What medication should be used for anxiety/restlessness?
- anxiety and agitation increase oxygen consumption (increased metabolic rate)
- sedatives, opioids, or muscle relaxants may be needed
- benzodiazepines (lorazepam), opioids (morphine)
- nurses are required to monitor for sedation (impact on oxygenation) and encourage the use of non-pharmacological interventions
What’s important to treat in respiratory failure?
The underlying cause
- VQ mismatch - PE - anticoagulants to prevent clot enlargement
- pneumothorax - chest tube to re-inflate the lung field
- shunting - surgery to repair heart defects
What does maintaining cardiac output involve?
- increased work of breathing can increase intrathoracic pressure
- monitor heart rate, blood pressure, and peripheral perfusion (poor perfusion can be related to hypovolemia and high heart rates can increase cardiac output)
- treat with fluids or medications
What does monitoring hemoglobin involve?
- hemoglobin carries oxygen molecules to the cells
- low hemoglobin = poor oxygenation
- monitor for signs of poor oxygenation
- monitor hemoglobin and hematocrit levels
- monitor red blood cell count
- assess ability to perform ADL’s
What does nutritional therapy involve?
- increased respiratory efforts = increased metabolic rate
- ensure patients are receiving enough nutrients
- take into consideration previous medical conditions
- monitor weight, input and output, and bowel pattern
- monitor for aspiration
- provide high value nutrients and fluids
What is acute respiratory distress syndrome?
- sudden and progressive form of acute respiratory failure
- often triggered by an inflammatory response
- alveolar-capillary membrane becomes damaged which leads to increased permeability
- alveoli become filled with fluid which impairs gas exchange
What is the most common cause of acute respiratory distress syndrome?
Sepsis (gram negative bacteria)
- can also occur due to trauma for gastric aspiration, inhalation of corrosive materials, DKA and pancreatitis
What is the first stage of ARDS?
Injury/Exudative phase
- occurs 1-7 days after initial direct injury to the lungs
- neutrophils adhere to pulmonary circulation, damaging pulmonary vascular lining which increases capillary permeability
- fluid invades the interstitial space and slowly enters the alveolar space
- surfactant is damaged - impairing lung compliance
- hyaline membranes begin to line alveoli which leads to the development o atelectasis and fibrosis
What is the second stage of ARDS?
Reparative or proliferative phase
- begins 1-2 weeks post injury - inflammatory response
- influx of neutrophils, monocytes, and lymphocytes with fibroblast proliferation = dense fibrous tissue
- increased pulmonary vasculature resistance - pulmonary hypertension
- hypoxemia worsens due to thickened alveolar membrane and widespread fibrosis
What is the third stage of ARDS?
Fibrotic (chronic or late stage)
- occurs 2-3 weeks post lung injury
- the lungs are remodelled by collagenous and fibrous tissues
- diffuse scarring impact lung compliance
- outcomes for patients in this stage are poor
What are some defining features of ARDS?
- hypoxemia that persists even when 100% oxygen is given
- decreased pulmonary compliance
- dyspnea, changes in respiratory pattern, work of breathing
- abnormal lung sounds, not heard initially (injury is occurring in interstitial spaces, not airways)
What are the signs and symptoms of ARDS?
- increased work of breathing
- hyperpnea, noisy respirations
- cyanosis
- retractions - intercostally (between ribs) or substernally (below ribs)
What is involved in a diagnosis assessment for ARDS?
- blood gases - PaO2 < 60mmHg
- despite oxygen therapy - intubation and mechanical ventilation
- sputum culture - bronchoscopy
- chest x-ray - white out appearance
What are some interventions for ARDS?
- intubation and mechanical ventilation with positive end expiratory pressure (PEEP)
- frequent respiratory assessment (q1hr)
- antibiotics and IV access - monitor fluid status
- nutritional therapy - enteral nutrition (tube feeding)
- turning q2hr
- oral care and skin care
What is SARS and what does it stand for?
Severe acute respiratory distress syndrome
- serious acute respiratory infection cause by coronavirus
- treatment is the same as respiratory failure
- if it worsens, use ARDS treatment plan
- outbreak in 2012
