Respiratory Assessment, Techniques and Monitoring Systems

The lungs, in conjunction with the circulatory system, deliver oxygen to and expel carbon dioxide from the cells of the body. The upper respiratory system warms and filters air, while the alveoli, the end-point structure of the lungs, accomplish gas exchange.

1. Upper respiratory system: nose, sinuses, and nasal passages; pharynx, tonsils, and adenoids; larynx, epiglottis, glottis, vocal cords, and cartilages.
2. Lower respiratory system: lungs, pleura, mediastinum     - Lung lobes: left (upper and lower); right (upper, middle, lower)     - Bronchi, which divide into bronchioles, then into alveoli, where gas exchange occurs.

Ventilation vs Respiration: ventilation is the mechanical movement of air in and out of the lungs, whereas respiration is the gas exchange that occurs in the alveoli.

• Inspiration is the initial third of ventilation, where the diaphragm and external intercostal muscles (main muscles of respiration) contract to increase the space in the thoracic chamber, producing negative inspiratory pressure (NIP), moving air into the lungs.
• Expiration is the latter two-thirds of ventilation, when relaxation occurs and intrathoracic pressure increases, pushing air out of the lungs.
• Gas exchange is the diffusion of oxygen from air into the blood, and diffusion of carbon dioxide from the blood into the air.

Assessment of Breath Sounds

Normal breath sounds are those heard at different areas of the lungs in normally functioning lungs.

1. Tracheal Breath Sounds are heard at the level of the trachea, characterized as harsh, discontinuous sounds.
2. Bronchial Breath Sounds are heard at the level of the bronchi, characterized as high-pitched.
3. Broncho-vesicular Breath Sounds are heard at the level of the scapula, characterized as medium-pitched.
4. Vesicular Breath Sounds are heard at the level of the lower lobes, characterized as low-pitched.

Abnormal (Adventitious) breath sounds are extraneous sounds produced by abnormalities of the lungs and airways.

1. Rales indicate elevated moisture in the lungs.
2. Crackles, a more severe (coarse) form of rales indicating accumulation of fluids in the lungs. Often observed in pulmonary edema secondary to heart failure and pneumonia.
3. Rhonchi are sounds continuously created by secretions in the airway.
4. Wheezes are heard when airways become constricted, such as in asthma and bronchospasm.
5. Friction Rubs are heard from pleurisy and pericarditis, when the pleura rubs against other membranes producing a leather-like scratching.

Lung Parameters and Capacities

1. Ventilation Perfusion (V/Q) Ratio: the degree between air entering the lungs (ventilation) and oxygen that perfuses into the blood (perfusion). This ratio must be even in order for adequate gas exchange. Shunting occurs when an imbalance of ventilation and perfusion. This results in hypoxia.     - A low V/Q ratio can occur in conditions like asthma or COPD, where more ventilation than perfusion occurs. A high V/Q ratio can occur in pulmonary embolism or conditions where blood flow is restricted, leading to more perfusion than ventilation.
2. Tidal Volume (V_T or TV) is the amount of air volume that moves in or out of the lungs with each breath at rest.     - Reduced tidal volumes is found in restrictive lung diseases or neuromuscular disorders, whereas increased tidal volume might be seen in hyperventilation conditions.
3. Inspiratory/Expiratory Reserve Volume (IRV, ERV): the extra volume of air that can be inspired or expired with maximal effort after a normal, quiet inspiration or expiration.     - These may also be reduced in restrictive lung conditions where lung volumes are compromised.
4. Vital Capacity (VC): the maximum volume of air exhaled from a maximal inspiration. This is the summation of V_T, IRV, and ERV.     - Decreased vital capacity can indicate restrictive lung diseases or weakness of respiratory muscles. It is a key measure in assessing overall function of the lungs and can be used to monitor disease progression or response to treatment.
5. Forced Vital Capacity (FVC): the maximum amount of air you can exhale from your lungs after fully inhaling. It is equal to about 80% of total physiologic capacity.
6. Forced Expiratory Volume (FEV): the volume exhaled forcefully over time in seconds. Time is indicated as a subscript, and is usually one second (FEV₁).     - This is particularly useful in diagnosing and monitoring obstructive lung diseases like asthma and COPD. This is used in conjunction with FVC in calculating the FEV₁/FVC ratio, which helps in distinguishing between obstructive and restrictive lung conditions.

Pulmonary Function Tests

1. A spirometer measures volumes of air exhaled and is used to assess lung capacities. TV varies from breath to breath, and as such should be measured several times. It determines peak flow rate, the maximal expiratory flow, and is frequently done by patients using a home spirometer.
2. A monometer measures inspiratory effort and can be attached to a mask or endotracheal tube to occlude the airway and measure pressure.     - Normal inspiratory pressure is approximately 100 cm H₂O. If this value becomes less than 25 cm H₂O, the patient will usually require mechanical ventilation.
3. A pulse oximeter is a noninvasive method to monitor the oxygen saturation (SpO₂) normally at ≥95% of the blood. This is supplemental to ABG analysis, and may be unreliable. Also read: Pulse Oximetry
4. Arterial blood gas (ABG) analysis is the measurement of arterial oxygenation and carbon dioxide levels, and assesses acid-base balance. It is also used to assess the adequacy of alveolar ventilation and the ability of the lungs to provide oxygen and remove carbon dioxide. Also read: Arterial Blood Gas Monitoring
5. Other diagnostic tests include:     - Imaging Studies: chest x-ray (CXR), computed tomography (CT) scan, magnetic resonance imaging (MRI), fluoroscopic studies and angiography, radioisotope procedures (lung scans), bronchoscopy, and thoracoscopy     - Sputum Tests     - Thoracentesis     - Biopsies

Respiratory Conditions

Upper Airway Obstruction

This may be caused by foreign bodies or materials, enlargement of tissues in the walls of the airway, pressure on the walls of the airway, or altered level of consciousness. Assessment utilizes inspection, palpation, and auscultation.

Airway Management

A more in-depth discussion of this section can be found here: Airway Management

1. Oropharyngeal Airway (OPA): also known as an oral bite block. It is a temporary airway used to relieve upper airway obstruction resulting from tongue relaxation, secretions and seizures. This may trigger the gag reflex and cause vomiting, and as such is not recommended for alert clients.     - Frequently assess the lips and tongue to identify pressure areas.     - These are removed at least every 24 hours to allow for assessment of pressure areas and to provide oral hygiene.
2. Nasopharyngeal Airway: also known as a nasal trumped. It maintains airway patency and is used to facilitate nasotracheal suctioning. Its sizes range from 26 to 35 Fr.     - Complications: bleeding, sinusitis, erosion of the mucous membranes     - Frequently assess pressure areas and occlusion due to secretions.     - Rotate the tube from nostril to nostril at least daily.
3. Laryngeal Mask Airway: an endotracheal tube with a small mask on one end that can be passed orally over the larynx. This provides ventilatory assistance and prevents aspiration.     - The “Combitube”, an esophageal/tracheal double-lumen airway is used for difficult or emergency intubation, allowing for blind placement.
4. Endotracheal (ET) Tube: inserted into the trachea through the mouth or the nose. An artificial airway used when a patent airway cannot be maintained and adjunct devices for mechanical ventilation are inadequate.     - Insertion utilizes a laryngoscope to visualize the upper airway. The tube enters through the vocal cords and into the trachea, to 2 to 4 centimeters above the carina (where the trachea bifurcates). The tube is anchored via cuff (also prevents air leakage and aspiration).     - Proper placement is confirmed through the presence of equal bilateral breath sounds, excursion during inspiration, and the absence of breath sounds over the stomach. Capnography of the ET tube should return a PETCO₂ of 35 to 40 mm Hg. Absolute confirmation of placement is done with a portable chest x-ray (CXR).     - Once verified, the tube should be anchored with tape or an ET fixation device. The centimeter marking of the tube at the lip is documented per shift.     - An ET tube may only be used for no more than three weeks, use for more than 10 to 14 days usually indicates the need for a tracheostomy.     - Complications include laryngeal and tracheal damage, laryngospasm, aspiration, infection and discomfort, and vocal cord paralysis (hence why the device should not be used for longer than three weeks).

Mechanical Ventilation

Mechanical ventilation is a form of assisted ventilation, either completely or partially taking over all parts of the work performed by the respiratory muscles and organs. It is indicated in patients whose ability to exchange carbon dioxide is compromised to support gas exchange until the disease process is resolved. The most common form of mechanical ventilation used in the acute care setting is positive pressure ventilation (PPV), where the ventilator forces oxygen into the lungs with each breath through an endotracheal tube or tracheostomy tube. This may deliver air until a preset tidal volume is reached (volume-cycled modes) or until a preset pressure is achieved (pressure-cycled modes). Modes are selected based on underlying pulmonary status, oxygenation status, and the presence of spontaneous breathing. These are the various modes of ventilation based on how ventilation is triggered or what parameters are used:

1. Assist-Control Ventilation (ACV) delivers a preset volume each time the patient attempts to breath, or if the patient has failed to breathe within a preset interval; there is an absolute minimum number of breaths per minute that must be achieved. This mode is used in patients with weak respiratory muscles.
2. Synchronized Intermittent Mandatory Ventilation (SIMV) is a mode with a present volume and rate delivered at a mandatory rate, but with the patient able to take spontaneous breaths in between mandatory breaths with their own effort, unsupported by the ventilator. This is commonly used for weaning patients off of ventilator support; those who require minimal ventilation.
   • The timing of the mandatory breaths and spontaneous breaths minimizes competition between the patient and ventilator.
3. Pressure-Controlled Ventilation (PCV) delivers positive-pressure breaths until a maximum amount of airway pressure is reached, then the inspiratory phase of the breath stops. A maximum inspiratory pressure is set to help minimize ventilator-induced lung injury (VILI). The pressure is adjusted to achieve a goal tidal volume as designated by the physician. This goal tidal volume is based on the patient’s weight and pulmonary status.
4. Pressure-Regulated Volume Control (PRVC) is a type of PCV where pressure adjustments are done to aim for a preset tidal volume; changes in lung compliance (e.g. the lungs become stiffer) is detected and the pressure requirement is adjusted until tidal volume is back within the preset range.
5. Positive End-Expiratory Pressure (PEEP) holds positive pressure in the alveoli even during expiration. It is frequently used as a supplement to most modes of ventilation. It prevents alveoli from collapsing at end-expiration, improves oxygenation, and increases functional residual capacity. It is normally set between a range of 2 to 24 cm H₂O of pressure.
   • High PEEP settings (>10 cm H₂O) may increase intrathoracic pressure, impeding venous return (leads to decreased cardiac output, hypotension, and increased intracranial pressure). To manage this, preload of the heart should be increased with fluids or a vasopressor.
   • High PEEP settings may also increase airway pressure. This produces risk for VILI and V/Q shunting.
6. Continuous Positive Airway Pressure (CPAP) is similar to PEEP, but provides positive pressure during spontaneous breaths. It increases oxygenation by preventing the closure of alveoli at end-expiration, maximizing functional residual capacity (FRC). It is generally only set to a range of 5 to 10 cm H₂O, as higher pressures may result in hypotension or pneumothorax. This may also be used to wean patients as a non-invasive method.
7. Pressure Support Ventilation (PSV) augments the tidal volume of spontaneous breaths by delivering a preset positive pressure during inspiration. This increases patient comfort by decreasing the amount of work required in each spontaneous breathing. This may be added to SIMV or CPAP for weaning. Its setting ranges from 8 to 20 H₂O.

Ventilator Settings

These are individualized settings adjusted according to ABG measurements and SaO₂ readings.

Parameter	Description	Range
Tidal Volume (TV, VT)	The amount of oxygen delivered to a patient with each preset ventilated breath	5 to 15 mL/kg, avg 10 mL/kg.
Back-up Rate (BUR) or Respiratory Rate (RR)	The number of breaths per minute that the ventilator is set to deliver.	4 to 20 breaths/min
Fraction of Inspired Oxygen (FiO2)	The percentage of oxygen within the air delivered by the ventilator.	0.21 to 1.0 (21% to 100%)
Inspiratory to Expiratory Ratio (I:E Ratio)	The duration of time spent during inspiration vs. the duration of time spent during expiration	1:2
Sensitivity	The amount of effort the patient must generate before the ventilator gives a breath, for modes that support breathing. Low = more effort is required; high = respiratory effort may compete with the ventilator
Flow Rate	How fast TV will be delivered during inspiration. High settings increase airway pressure, and low settings decrease airway pressure.
Pressure Limit	The maximum amount of pressure the ventilator generates to attempt to achieve the preset TV. Once reached, ventilation stops.

There are also multiple terms related to mechanical ventilation:

1. Compliance: the elasticity of lung tissue. A decrease in compliance increases resistance to breath.
2. Peak Inspiratory Pressure (PIP, aka peak airway pressure): the airway pressure at maximum inspiration
3. Low Pressure Alarm: an alarm that indicates a leak or disconnection in the ventilator circuit has occured, resulting in decreased system pressure. The patient fails to receive adequate ventilation, if any.
4. High Pressure Alarm: an alarm that indicates excessive PIP, producing heightening risks of VILI.
5. Volutrauma: an injury to lung tissue caused by overdistention of alveoli; caused by excessive volume.
6. Barotrauma: an injury to lung tissue from too much pressure on the airway.
7. Atelectrauma: low intra-alveolar pressure causing collapse of alveoli resulting in VILI.

Ventilator-Associated Pneumonia

Ventilator-Associated Pneumonia (VAP) is pneumonia related to the use of ventilators. There is a bundle of care for VAP, discussed further [[#Pneumonia#Ventilator-Associated Pneumonia|later in this page]].

Weaning Patients off of MV

1. Assist-Control Ventilation (ACV) may be used. Control rate is decreased, and the patient is expected to strengthen their respiratory muscles by triggering more progressive respirations.     - Nursing management is to watch out for rapid or shallow breathing, use of accessory muscles, decrease in LOC, increases in CO₂, and tachycardia. These indicate inadequacy and may require reinstitution of mechanical ventilation.
2. Synchronized Intermittent Mandatory Ventilation (SIMV) is indicated for patients who have satisfied weaning criteria, but cannot sustain adequate spontaneous ventilation for long periods. As respiratory muscles strengthen, the pressure is decreased.
3. T-piece: a T-shaped tubing is connected to the endotracheal tube in order to provide high oxygen while reducing support from the mechanical ventilator. It is usually used when the patient is awake and alert, breathing without difficulty, and has good gag and cough reflex.     - Nursing management is to watch out for respiratory distress and hypoxia.

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Nursing Care of Clients with Altered Ventilatory Function

Respiratory emergencies may range from “shortness of breath”, or dyspnea, to complete respiratory arrest, or apnea. These conditions can result from a large number of causes. Most typically, these causes involve the lungs.

Pulmonary Embolism

A pulmonary embolism is an embolus (either thrombotic or non-thrombotic) that lodges in the pulmonary artery system. It can damager part of the lung due to restricted blood flow, decrease oxygen levels in the blood, and affect other organs as well. Large or multiple blood clots can b e fatal. The blockage can be life-threatening. Risk factors include:

1. Injury or damage leading to blood clot formation
2. Inactivity for prolonged periods
3. Medical conditions or treatment procedures that can cause blood to clot easily

Clinical Manifestations

1. Virchow’s Triad: venous stasis, coagulation problems, and vessel wall injury
2. Chest pain
3. Tachycardia, Tachypnea: attempting to compensate for impaired gas exchange
4. Anxiety, Restlessness
5. Clammy or bluish skin from decreased perfusion

Diagnostics

1. Chest X-ray may be used to rule out other disorders with the same presenting manifestations.
2. ABG Analysis
3. D-dimer Test detects clot fragments from clot lysis; this determines if clot formation (and subsequent breakdown) is elevated, which is consistent with the etiology of pulmonary embolism.
4. ECG
5. V/Q Scan, Pulmonary Angiography, Spiral CT Scan: angiography is a gold standard for detecting PE from filling defects of the lungs. The same goes for a spiral CT scan that can visualize the pulmonary arteries. A normal V/Q scan virtually rules out PE.

Treatment

1. Oxygenation (ET and mechanical ventilation if necessary)
2. Heparin Therapy to act against coagulation
3. Surgery: physical removal of the clot (pulmonary embolectomy) or placement of an umbrella filter (usually in the IVC) to trap blood clots before they can dislodge in the lungs.
4. Preventive measures: acting against coagulable states, trauma, immobility, and other risk factors for embolus formation.

Acute Respiratory Distress Syndrome (ARDS) or Lung Injury

A syndrome including inflammation and increased permeability of the alveolocapillary membrane (resulting in outflowing of fluids to the alveolar sacs, which impede gas exchange) that occurs as a result of an injury to the lungs. This condition is fatal when left undiagnosed or treated for 48 hours. Risk factors include:

1. Critical illness
2. Age (≥60 years old)
3. Malignancy
4. Cigarette Smoking, COPD
5. Aspiration pneumonia or systemic illness (burns, sepsis, drug overdose)

Clinical Manifestations

1. Restlessness resulting from decreased oxygenation of the brain.
2. Hyperventilation, tachycardia, dyspnea in an attempt to compensate for hypoxia.
3. Hypoxemia as a result of ineffective gas exchange.
4. Hypotension, cyanosis, and decreased urinary output in severe cases. Prolonged hypoxia of vital organs results in hypotension (which results in oliguria) and cyanosis.

Diagnostics

The primary diagnostic treatment is a chest x-ray, which reveals lung whiteout; imaging showing opacity of the entire lung field due to large pleural effusion.

Treatment

The goal of treatment is to improve and maintain oxygenation and prevent respiratory and metabolic complications.

1. Fluid management to maintain tissue perfusion
2. Corticosteroid therapy to decrease alveolocapillary membrane permeability
3. Enteral feeding
4. Supplemental oxygen, MV if necessary.

Acute Respiratory Failure

Respiratory gas exchange impaction to a degree that normal cellular function becomes jeopardized. It is officially defined as a PaO₂ of less than 50 mm Hg, a PaCO₂ of greater than 50 mm Hg, and a pH of less than 7.30. Recall that O₂ is normally 80 to 100 mm Hg, CO₂ is normally 35 to 45 mm Hg, and pH is normally 7.35 to 7.40.

Two types of respiratory failure exist according to the presence of carbon dioxide abnormality or not; hypoxia is always present in respiratory failure.

• Type I ARF: “Hypoxemic”; low oxygen with normal or low carbon dioxide levels.
• Type II ARF: “Hypercapnic”; low oxygen with high carbon dioxide.

Type I (Hypoxemic ARF)	Type II (Hypercapnic)
Lung failure, respiratory insufficiency	Pump failure, ventilatory failure
Failure of the lungs and heart to provide adequate oxygen	Failure of the lungs to eliminate adequate CO2.
PaCO2 < 50 mm Hg with normal or decreased PaO2	PaCO2 > 50 mm Hg
Alveolar hypoventilation	Increased physiologic dead space
Associated with acute diseases of the lungs (pulmonary edema, ARDS, pneumonia)	Drug overdose, neuromuscular disease, chest wall deformity, COPD

Causes of ARF vary, but are generally categorized into four groups in adults:

1. Impaired Ventilation:     - Spinal cord injury above C5     - Phrenic nerve damage     - Neuromuscular blockade     - Guillain-Barré Syndrome     - CNS depression     - Respiratory muscle fatigue
2. Impaired Gas Exchange:     - Pulmonary edema     - ARDS     - Aspiration pneumonia
3. Airway Obstruction:     - Aspiration of foreign bodies     - Thoracic tumor     - Asthma     - Bronchitis     - Pneumonia
4. Ventilation-Perfusion Abnormalities:     - Pulmonary embolism     - Emphysema

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Chronic Obstructive Pulmonary Disease

This is an umbrella term for various diseases (e.g. chronic bronchitis, emphysema, chronic asthma). It is also described as a slowly progressive and irreversible disease, although some patients may show a degree of reversibility with bronchodilator treatment. This usually occurs in people over 50 years of age and smokers (the most major factor in development).

Assessment

COPD may be classified as mild, moderate, or severe:

• Mild: the only abnormal sign is a “smoker’s cough”.
• Moderate: breathlessness, and/or wheezing upon moderate exertion; coughing; and generalized reduction in breath sounds.
• Severe: breathlessness even at rest, cyanosis, prominent wheezing or coughing, and lung overinflation.

Consider and record the following:

• Current treatment modalities: inhalers, nebulizers, antibiotics, steroids, oxygen therapy, and theophyllines (a bronchodilator)
• Exercise tolerance
• Previous admissions, especially to intensive care or treatment with non-invasive ventilation; the reason for emergency department attendance.

It is important to identify whether the exacerbation has been accompanied by an increase in the amount or type of sputum produced; a recent fall or chest injury may be the cause of the symptoms.

 In the emergency department, the following is assessed:  - Coughing; sputum color and amount if present.  - Cyanosis  - Tachypnea, wheezing  - Accessory muscle usage; lip pursing on expiration  - Chest expansion (often poor)  - Fever  - Dehydration  - Confusion or reduction in level of consciousness  - Pain

Consider whether the patient is septic, and treat any signs of sepsis, severe sepsis, or septic shock immediately.

Diagnostics

• Vital Signs: continuous monitoring of HR, RR, and SpO₂.
• Chest X-ray: visualize physiologic abnormalities e.g. hyperinflated lung fields
• Electrocardiogram
• ABG Analysis as soon as possible to determine appropriate respiratory therapies
• FBC, U&E, and Theophylline level (if applicable)
• Sputum culture and sensitivity if purulent
• Blood cultures if the patient is pyrexial (has fever, check for sepsis)

Nursing Interventions

• Provide reassurance. Clients with compromised respirations often experience restlessness and anxiety.
• Position the patient in an upright position (30° - 45°). This aids in respiration.
• O₂ therapy to keep saturations in the range of 88% to 92%. Strict control of oxygen therapy is required to prevent hyperoxia in clients with chronic hypercapnia, as this may result in the loss of hypoxic drive.
• Nebulization to deliver bronchodilators and other medications directly to the lungs, helping to open airways and reduce bronchospasm. Continuous nebulization may be necessary during acute exacerbations to maintain relief from symptoms.
• Steroids are used as antiinflammatory agents.
• IV Theophylline are given if nebulizers are not effective in inducing bronchodilation.
• Assessment for NIV: regularly check if the patient may utilize non-invasive ventilation. Long-term use of mechanical ventilation results in heightened risks for VILI or VAP.
• Mouth care is essential for hygiene and reducing risk for oral infections and pneumonia.
• IVF for Dehydration: dehydration may occur from COPD exacerbations and medications. This thickens secretions, and makes them harder to clear. IVF helps maintain hydration, thin secretions, and improve overall respiratory function.
• Analgesia is important for quality of life. Pain can increase respiratory rate and effort, leading to further respiratory distress.
• AVPU (Alert, Voice, Pain, Unresponsive) Scale and GCS (Glasgow Coma Scale) are used to assess a patient’s level of consciousness and neurological status. Monitoring these scores helps identify changes in mental status, which is often the first indication of worsening respiratory function or other complications.

Management

1. Noninvasive Ventilation (NIV) is increasingly being used in ED resuscitation rooms, as evidence indicates these reduce mortality and the need for invasive ventilation. These should be used for patients who:     - have respiratory acidosis (pH <7.35, PaCO₂ >45 mm Hg) that persists despite maximal medical therapy;     - are not moribund (at the point of death), with a GCS score of >8.     - are able to protect the airway.     - are cooperative and conscious.     - have few comorbidities.     - are hemodynamically stable.     - have no excess respiratory secretions.     - have potential for recovery to a quality of life acceptable to the patient.

Anesthetic Assessment

Ideally, patients should have an anesthetic assessment prior to the commencement of NIV in order to determine their sustainability and outline what the ceiling treatment should be. A DNR order may be completed at this time if the patient is not suitable for invasive ventilation.

2. Intensive Care: patients undergoing COPD exacerbation should not be automatically excluded from invasive ventilation if all other treatments are failing. The following will have to be considered:     - Quality of life (ideally, involve the family in this discussion)     - O₂ requirements when stable     - Co-morbidities     - Forced expiratory volume in one second (FEV₁): measures the lung function of COPD patients, indicating the severity of airflow obstruction. Very low FEV₁ may indicate a higher risk of complications from invasive ventilation.     - Body mass index (BMI): abnormal BMI may complicate ventilation and reduce chances of success.

Pneumonia

Pneumonia is an inflammation of the lung, which is characterized by exudation into the alveoli. It can be classified anatomically as lobar or by etiology. It is most commonly caused by bacteria. The terms pneumonia and chest infection are used interchangeably. It may be caused by any of over 100 microorganisms. Therefore, the treatment should be started before the causative organism has been identified. Some common ones include:

• Streptococcus pneumoniae (90% of cases)
• Haemophilus influenzae
• Staphylococcus aureus
• Legionella species

Pneumonia may be classified according to where the infection occurred:

• Community-Acquired Pneumonia (CAP): the individual was not hospitalized or institutionalized in a long-term care facility for 14 days or longer prior to the onset of symptoms.
• Hospital-Acquired Pneumonia (HAP): the individual displays symptoms 48 hours after admission.
• Ventilator-Associated Pneumonia (VAP): the individual displays symptoms 48 to 72 hours after intubation.
• Aspiration Pneumonia: micro-aspiration of bacteria colonizing the upper respiratory tract, macro-aspiration of gastric contents, indirect transmission from staff, or inhaled aerosols that cause pneumonia.
• Atypical Pneumonia: the causative agent differs from the common causative agents of pneumonia.

Assessment Findings

Consolidation of the lungs, where alveoli fills with secretions is the primary etiology of these findings:

• Expansion is reduced on the affected side
• There is percussion dullness over the area of consolidation
• Breath sounds are bronchial; adventitious crackles may be heard
• Tachypnea and central cyanosis
• Fever, sweats, and central cyanosis
• Coughing and sputum

Diagnostics

• Sputum microscopy, culture, and sensitivity
• Chest X-ray
• Pulse oximetry and ABG (if SpO2 is <93% on room air)
• FBC, U&E, CRP, and LFTs

Management

In the emergency department:

• Supplemental O₂ is provided to maintain SpO₂ >93%
• IV: fluids for dehydration, antibiotics (broad spectrum), antipyretics (if febrile), and analgesics
• Bronchoalveolar lavage may be used for patients who are immunocompromised, those who do not respond to antimicrobial therapy, or for those from whom a sputum sample cannot be obtained.

Nursing Interventions

• Positioning: upright for improving respiration
• Ensuring timely antimicrobial therapy
• Monitoring of hemodynamics, and electrolyte and electrolyte imbalances
• Adherence to infection prevention and control
• Ventilator-associated pneumonia care bundle

Ventilator-Associated Pneumonia

As previously mentioned, this classification is used for patients who develop the symptoms of pneumonia 48 hours after intubation via endotracheal tube or tracheostomy. Oral and/or gastric secretions may enter the airways from compromised integrity of the oropharynx and trachea. It significantly increases the length of mechanical ventilation, critical care stay, and overall hospital stay.

VAP is the most common post-admission infection in critical care patients.

Risk factors for VAP include a compromised immune system, the elderly, and those with chronic illnesses. Diagnosis is difficult due to the number of diagnoses that present with the same signs and symptoms (e.g., sepsis, ARDS, cardiac failure, lung atelectasis).

Diagnosis

A chest x-ray shows consolidation and new or progressive infiltrates within the lung fields.

Clinical signs include a fever >38°C, raised or reduced white blood cell count, new-onset purulent sputum, increased respiratory secretions/suctioning requirement, and worsening gas exchange.

Management (prevention) for VAP is organized through a bundle of care, which includes:

• Elevation of the head of the bed (HOB) by 30° to 45° to improve respiration and reduce risk for aspiration and subsequent pneumonia.
• Daily sedation vacations (temporary removal of sedation) and assessment of readiness to extubate.
• Stress ulcer prophylaxis: risk for stress ulcers is heightened during MV. Prophylaxis with proton pump inhibitors or H₂ blockers.
• Daily oral care with Chlorhexidine: elimination of oral bacterial colonization, which is a risk factor for pneumonia.
• Subglottic aspiration: a tracheal tube with a subglottic secretion drainage port is used if the patient is expected to be intubated for more than 72 hours. Secretions are aspirated via the subglottic secretion port every one to two hours.
• Tube Cuff Pressure: cuff pressure is measured every four hours, and is maintained within 20 to 30 cm H₂O or 2 cm H₂O above peak inspiratory pressure.
• Deep vein thrombosis (DVT) prophylaxis: anticoagulants/compression stockings to counteract the risk for DVT from immobility, to prevent a potential pulmonary embolism.

Complications

Pneumonia should be scored to assess severity, risk of death, and risk of ICU admission. This score may also guide subsequent treatment and the decision about the need for hospital admission. Scoring utilizes the CURB-65 system:

CURB-65	Clinical Feature	Points
C	Confusion	1
U	Urea > 7 mmol/L	1
R	RR ≥ 30	1
B	BP one or both of $\frac{\le 90mmHg}{\le 60mmHg}$	1
65	Age > 65	1
Scoring interpretation is as follows:

Score	Risk Group	30-day Mortality	Management
0 - 1	1	1.5%	Low-risk, consider home treatment if good social support and no other significant health problems.
2	2	9.2%	Probable admission vs. close outpatient management
3 - 5	3	22%	Admission, manage as severe

Sepsis is of particular concern as a sequelae of pneumonia in the elderly!

Any general assessment of the breathless patient should identify any signs of sepsis.

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