Acute Respiratory Failure Flashcards

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.
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2
Q

Adventitious breath sounds

A
  • Crackles
  • Rhonchi
  • Wheezes
  • Pleural friction rub
  • Stridor
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3
Q

Adventitious breath sounds

Stridor

A

Usually an indicator that pt has to be intubated. Airways too narrow.

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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
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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.
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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
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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
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8
Q

ABGs

A
pH = 7.35 - 7.45   
PaCO2 = 35 - 45   
HCO3 = 22 - 26
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9
Q

Types of hypoxemia

Type I Hypoxemic

A
  • Impaired gas exchange
  • Oxygenation failure
  • Pneumonia
  • Pulmonary edema
  • ARDS
  • Aspiration
  • Atelectasis
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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
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11
Q

PE

Risk factors

A
  • Cardiovascular disease or COPD
  • History of DVT
  • Immobilization
  • Surgery within the last 3 months
  • Malignancy
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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
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13
Q

PE

Virchow’s Triad

A

Three main mechanisms that favor the development of VTE

  • Venous stasis
  • Altered coagulability
  • Damage to vessel walls
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14
Q

PE

Most useful diagnostic test

A

Spiral CT

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15
Q

PE

Treatment

A
  • Oxygen/ ventilator support
  • Thrombolytics
  • Anticoagulants- Heparin
  • Inferior Vena-Cava Filters (IVC)
  • Surgery
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16
Q

Pneumothorax

Definition

A

Air in the pleural space

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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
  • 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
Q

ETT

A
  • 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
Q

ETT

Mouth or nose

A
  • Mouth, because you can see your way better.
  • Risk for infection with nose.
  • Mouth unless neck injury.
27
Q

ETT

Verify placement

A
  • 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
Q

Indicators for Mechanical Ventilation

A
  • 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
Q

Positive End Expiratory Pressure (PEEP)

A
  • 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
Q

Auto-Peep

A
  • 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
Q

Patient Monitoring

PIP

A
  • 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
Q

Alarms

A
  • 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
Q

Complications of Mechanical Ventilation

A
  • 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
Q

Barotrauma

A
  • 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
Q

Infection

A
  • 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
Q

Cardiovascular

A
  • Hypotension

- Decreased cardiac output, especially with PEEP

37
Q

Gastrointestinal

A
  • 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
Q

Psychosocial

A
  • 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
Q

Nursing care

A
  • 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
Q

Readiness to Wean

A
  • 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
Q

Stop Weaning

A
  • 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
Q

Evaluation

A
  • ABGs
  • Resume ventilator support
  • Identify cause
  • EXTUBATION
    • Determine need for secretion management
    • Assess
      > Stridor
      > Hoarseness
      > Change in VS
      > Low oxygen saturation