Acute Respiratory Failure Flashcards
(42 cards)
1
Q
Breathing regulators
Normal lung function vs COPD
A
- In persons with normal lung function, high levels of carbon dioxide stimulate respiration.
- Persons with COPD maintain higher levels of carbon dioxide as a baseline, and their ventilatory drive in response to increased carbon dioxide levels is blunted. In these patients, the stimulus to breathe is hypoxemia, a low level of oxygen in the blood.
2
Q
Adventitious breath sounds
A
- Crackles
- Rhonchi
- Wheezes
- Pleural friction rub
- Stridor
3
Q
Adventitious breath sounds
Stridor
A
Usually an indicator that pt has to be intubated. Airways too narrow.
4
Q
Oxygenation
PaO2
A
- PaO2: Partial pressure of oxygen dissolved in arterial blood.
- Normal value 80 to 100 mmHg
- Decreases in elderly 60-80 yo –> 60 to 80 mmHg
- Value < 60 mmHg is treated (hypoxemia)
- Value < 40 mmHg is life threatening because oxygen is not available for metabolism. Without treatment, cellular death occurs.
- Normal = 80 - 100 mmHg
- Mild hypoxemia = 60 - 80 mmHg
- Moderate hypoxemia = 40 - 60 mmHg
- Severe hypoxemia = below 40 mmHg
5
Q
Work of breathing
A
- Amount of effort required to maintain ventilation
- As WOB increases, more energy is needed
- If the WOB becomes too high, respiratory failure ensues and mechanical ventilator support is warranted.
6
Q
Respiratory failure
A
- A state of altered gas exchange resulting in abnormal blood gas values
- PaO2 < 60 mmHg and/or PaCO2 arterial blood value > 50 with a pH less than 7.30
7
Q
Compliance and resistance
A
- Compliance
- Distensibility or stretchability of the lung and chest wall.
- Determined by elasticity, “recoil”
- Compliance is better measured under static conditions
- Resistance
- Opposition to gas flow in the airways due to airway length, airway diameter, or flow rate of gases
8
Q
ABGs
A
pH = 7.35 - 7.45 PaCO2 = 35 - 45 HCO3 = 22 - 26
9
Q
Types of hypoxemia
Type I Hypoxemic
A
- Impaired gas exchange
- Oxygenation failure
- Pneumonia
- Pulmonary edema
- ARDS
- Aspiration
- Atelectasis
10
Q
Types of hypoxemia
Type II Hypercapneic Hypoxemic
A
- Impaired breathing pattern
- Ventilatory failure
- COPD
- Neurological system failure to stimulate respiration
- Muscular failure
- Skeletal alterations
11
Q
PE
Risk factors
A
- Cardiovascular disease or COPD
- History of DVT
- Immobilization
- Surgery within the last 3 months
- Malignancy
12
Q
PE
Clinical manifestations
A
- Dyspnea: sudden onset
- Tachypnea
- Pleuritic Chest Pain: pain on inspiration
- Cough
- Hemoptysis: coughing up bloody sputum
- Anxiety- feeling of impending doom
- Tachycardia
- Fever
13
Q
PE
Virchow’s Triad
A
Three main mechanisms that favor the development of VTE
- Venous stasis
- Altered coagulability
- Damage to vessel walls
14
Q
PE
Most useful diagnostic test
A
Spiral CT
15
Q
PE
Treatment
A
- Oxygen/ ventilator support
- Thrombolytics
- Anticoagulants- Heparin
- Inferior Vena-Cava Filters (IVC)
- Surgery
16
Q
Pneumothorax
Definition
A
Air in the pleural space
17
Q
Pneumothorax
Causes
A
- Trauma
- Rib fracture - Flail chest- clinical manifestations
> 3 or more rib fractures
> Inspiration paradoxical movement - Chest Tube Insertion
> Complete respiratory assessment
> Crepitus
> Air leak
- Rib fracture - Flail chest- clinical manifestations
- Spontaneous
18
Q
Adult (Acute) Respiratory Distress Syndrome (ARDS)
A
- Acute diffuse injury to the lungs, leading to respiratory failure
- Acute Lung Injury (ALI)
- IT IS THE MOST COMMON CAUSE OF MORTALITY R/T TRANSFUSIONS (TRALI)
- Sepsis is the most common cause
19
Q
ARDS
Clinical manifestations
A
- Dyspnea
- Tachypnea
- Decreased lung compliance
- Diffuse alveolar infiltrates
- Hypoxia
20
Q
ARDS
Diagnostic test
A
x-ray (total white out of the lung)
ABGs
Respiratory assessment - breath sounds. All you can hear is fluid
21
Q
ARDS
Initial signs
A
- Restlessness
- Disorientation
- Change in LOC
22
Q
ARDS
Treatment
A
- Supportive Care
- Mechanical ventilation with PEEP (MOST PTS ARE AT 5)
- Sodium bicarbonate infusion: treat acidosis
- Comfort
- Positioning: proning (ROTATION BED)
- Nutrition (ADMINISTER CARBS)
- Fluid and electrolytes
- Psychological support
23
Q
Bicarbonate
A
Most common buffer system
24
Q
Oxygen administration
A
- Oxygen to treat hypoxemia
- Humidify
- Flow rates > 4 L to prevent the mucous membranes from drying
- Mechanical ventilation
- If the secretions are thick despite adequate humidification of the delivered gases, the patient needs systemic hydration
25
ETT
- Uses
* Maintain an airway
* Remove secretions
* Prevent aspiration
* Provide mechanical ventilation
- Intubation should be performed in 30 seconds
- Tube is properly inserted 5 to 6 cm beyond the vocal cords into the trachea
- Verify placement (x-ray)
- Suctioning is done only as indicated by assessment and not according to a predetermined schedule.
- R mainstem bronchus is common because is straighter. Suspected when unilateral expansion of the right chest is observed during ventilation and breath sounds louder on the right than the left
26
ETT
| Mouth or nose
- Mouth, because you can see your way better.
- Risk for infection with nose.
- Mouth unless neck injury.
27
ETT
| Verify placement
- Auscultate epigastric area
- Auscultate bilateral breath sounds
- ETCO2 detector
- Esophageal detector device
- Chest x-ray: 3 to 4 cm above carina
- Secure tube when placement verified
- Record # cm at the lip line for reference
28
Indicators for Mechanical Ventilation
- Hypoxemia
* PaO2 ≤ 60 mm Hg on FiO2 > .50
- Hypercapnea
* PCO2 ≥ 50 mm Hg with pH ≤ 7.25
- Progressive deterioration
* Increasing RR
* Decreasing VT
* Increase WOB
29
Positive End Expiratory Pressure (PEEP)
- Positive airway pressure to mechanically assisted breaths
- Keeps airways open at end of expiration and increases FRC (functional residual capacity)
- Use to decrease amount of FiO2 needed
- RISK FOR BAROTRAUMA AND DECREASED CARDIAC OUTPUT
- Typical settings for PEEP are 5 to 20 cm H2O
30
Auto-Peep
- Spontaneous development of PEEP
- Caused by gas trapping
* Insufficient expiratory time
* Incomplete exhalation
> Rapid RR
> Airflow obstruction
> Inverse I:E ventilation
- MORE AIR STAYS IN LUNGS
31
Patient Monitoring
| PIP
- Maximum pressure that occurs during inspiration
- Increases with airway resistance
> Secretions
> Bronchospasms
> Biting ETT
> Decreased lung compliance
- Should never be higher than 40 cm H2O
> HIGHER PRESSURES CAN RESULT IN VENTILATOR-INDUCED LUNG INJURY
32
Alarms
- Never shut alarms off; silence only
- When an alarm sounds, the first thing to do is look at the patient.
- Manually ventilate if uncertain of problem
- If pt is disconnected from the ventilator circuit, quickly reconnect the patient to the machine
33
Complications of Mechanical Ventilation
- Intubation of right main stem bronchus
- ETT malposition / extubation
- Unplanned extubation
* Most frequent methods are
> By using the tongue
> By using hands to remove tube
* Reassure patient
* Provide analgesia and sedation
- Laryngeal / tracheal injury
* Monitor cuff pressure
- Skin breakdown
* Damage to oral & nasal mucosa
> ETT should be repositioned daily to prevent pressure necrosis
> Nasal intubation -> higher risk of sinusitis
34
Barotrauma
- MEANS PRESSURE TRAUMA. IT IS THE INJURY TO THE LUNGS ASSOCIATED WITH MECHANICAL VENTILATION
- Pneumothorax
- Tension Pneumothorax
* High PIP, mean airway pressure
* Decreased breath sounds
* Tracheal shift
* Subcutaneous crepitus
* Hypoxemia
- Treat Tension Pneumothorax EMERGENTLY
* Manually ventilate
* Needle thoracostomy
> 2nd intercostal space - mid-clavicular line
35
Infection
- Normal protective mechanisms bypassed by ETT tube
* Risk for Ventilator-associated pneumonia (VAP)
* Incidence is highest in the first 5 days of mechanical ventilation
* Factors that contribute to VAP include:
> Poor oral hygiene
> Aspiration
> Contaminated respiratory therapy equipment
> Poor hand washing by caregivers
> Breach of aseptic technique, inadequate
> Inadequate humidification or systemic hydration
> Decreased ability to produce effective cough
- Ventilator bundle
* Head of bed 30 degrees
* Awaken daily and assess readiness to wean
* Stress ulcer prophylaxis
* DVT prophylaxis
36
Cardiovascular
- Hypotension
| - Decreased cardiac output, especially with PEEP
37
Gastrointestinal
- Complications
* Stress ulcers
* GI bleeding
- Interventions
* Stress ulcer prophylaxis
* Provide nutritional support
* Assess swallowing prior to initiating oral feedings due to epiglottis not closing tight enough.
* Provide nutritional support within 24 hours
38
Psychosocial
- Stress
- Anxiety
- Dysynchrony, if the ventilator is not properly set or if the patient resists breaths.
- Noise of the ventilator and the need for frequent procedures (suctioning) leads to altered sleep-wake patterns
- Dependence. Pt may become psychologically dependent on the ventilator.
39
Nursing care
- Communication: lack of vocal expression has been identified as a major stressor that elicits feelings of panic, isolation, anger, helplessness and sleeplessness. Writing/mouthing words.
- Medications
* Analgesics: morphine and fentanyl. Writing/mouthing words.
* Sedatives: benzodiazepines, neuroleptics, and propofol
* Neuromuscular blocking agents (NMBAs): paralytic agents
40
Readiness to Wean
- Underlying cause for mechanical ventilation resolved
- Hemodynamic stability; adequate cardiac output
- Adequate respiratory muscle strength
- Adequate oxygenation without a high FiO2 and/or high PEEP
- Absence of factors that impair weaning (COMORBIDITIES)
- Mental readiness
- Minimal need for medicines that cause respiratory depression
41
Stop Weaning
- Respiratory rate > 30 or < 8 breaths/min
- Low spontaneous VT
- Labored respirations
- Use of accessory muscles
- Low oxygen saturation
- HR or BP changes > 20% from baseline
- Dysrhythmias (e.g., PVCs)
- ST-segment elevation
- Decreased level of consciousness
- Anxiety, agitation
42
Evaluation
- ABGs
- Resume ventilator support
- Identify cause
- EXTUBATION
* Determine need for secretion management
* Assess
> Stridor
> Hoarseness
> Change in VS
> Low oxygen saturation
