Chapter 3: Management of Patients with Chest and Lower Respiratory Tract Disorders (Part 3)

Empyema

accumulation of thick, purulent fluid within the pleural space, often with fibrin development and a loculated (walled-off) area where infection is located

causes of empyema

- bacterial pneumonia or lung abscess

- penetrating chest trauma

- hematogenous infection of the pleural space

- nonbacterial infections

- iatrogenic causes (after thoracic surgery or thoracentesis)

Diagnostic test for Empyema

- chest CT

- thoracentesis under utz guidance

Methods to drain pleural fluid in empyema

1. Thoracentesis (needle aspiration)

2. Tube thoracostomy

3. Open chest drainage via thoracotomy

Acute Respiratory Failure

sudden and life-threatening deterioration of the gas exchange function of the lungs and indicates their failure to provide adequate oxygenation or ventilation for the blood

Acute Respiratory Failure

defined as hypoxemia and hypercapnia with acidosis

hypoxemia

a decrease in arterial oxygen tension [PaO2] to less than 60 mmHg

hypercapnia

an increase in arterial carbon dioxide tension [PaCO2] to greater than 50 mmHg

acidosis

an arterial pH of less than 7.35

Ventilatory failure mechanisms

- Drug overdose

- Head trauma

- Infection

- Hemorrhage

- Sleep apnea

- Neuromuscular dysfunction (MG,GBS,ALS)

- Musculoskeletal dysfunction (chest trauma, malnutrition)

- Pulmonary dysfunction (COPD, Cystic fibrosis)

Oxygenation failure

- Pneumonia

- Heart failure

- ARDS

Early Signs of Acute Respiratory Failure

- restlessness

- fatigue

- headache

- dyspnea

- air hunger

- tachycardia

- increased blood pressure

Clinical Manifestations of Acute Respiratory Failure

As the hypoxemia progresses, more obvious signs may be present, including:

- confusion

- lethargy

- tachycardia

- tachypnea

- central cyanosis

- diaphoresis

- respiratory arrest

Management for Acute Respiratory Failure

- correct underlying cause

- restore adequate gas exchange in the lungs: ET intubation and Mechanical Ventilation

Endotracheal Intubation

- involves passing an ET tube through the nose or mouth into the trachea

- Advantage: provides a patent airway

- Disadvantage: discomfort, cough and swallowing reflex is depressed-- risk of aspiration and ulceration

oral route

preferred route of ET intubation

20-25 mmHg

normal cuff pressure of ET intubation

High cuff pressure

could cause:

- tracheal bleeding

- ischemia

- pressure necrosis

Low cuff pressure

risk of aspiration pneumonia

sitting/high-Fowler position

position of patient following extubation

Tracheostomy

- surgical procedure in which an opening is made into the trachea

- used to maintain a patent airway, bypass an upper airway obstruction, facilitate removal of tracheobronchial secretions

- replace an ET tube and prevent aspiration

- performed under GA

percutaneous tracheostomy

can be performed at bedside,with the use of local anesthesia and sedation and analgesia

Early Complications of Trachoestomy

- accidental decannulation

- bleeding

- air embolism

- aspiration

- subcutaneous emphysema

- laryngeal damage

Late Complications of Tracheostomy

- airway obstruction due to accumulation of secretion

- tracheoesophageal fistula

- necrosis

Mechanical Ventilation

positive- or negative-pressure breathing device that can maintain ventilation and oxygen delivery for a prolonged period

Indication for Mechanical Ventilation

If a patient has evidence of respiratory failure or a compromised airway

positive pressure ventilator

- inflate the lungs by exerting positive pressure on the airway, pushing air in, similar to a bellows mechanism, and forcing the alveoli to expand during inspiration.

- has 3 types

3 types of positive pressure ventilator

A. Volume-cycled ventilators

B. Pressure-cycled ventilators

C. High frequency oscillatory support ventilators

Non-invasive Positive pressure ventilators

- no need for ET

- usually used for pt's with sleep breathing related disorders

Continuous positive airway pressure (CPAP)

- effective treatment for pts with obstructive sleep apnea

- same air pressure on inhale and exhale

Bilevel positive airway pressure (BiPAP)

- has a backup rate (BUR)

- BiPAP is most often used for patients who require ventilatory assistance at night, such as those with severe COPD or sleep apnea

- most successful with patients who are highly motivated

- different air pressure levels for inhale and exhale

Inhalation

during this process, the air pressure is greater when BIPAP is utilized

Backup rate

ensures that the patient receives a set number of breaths per minute

Ventilator modes

- refers to how breaths are delivered to the patient

1. Controlled mechanical ventilation (CMV)

2. Continuous mandatory ventilation (aka Assist control or AC mode)

3. Intermittent mandatory ventilation (IMV)

4. Synchronized intermittent mandatory ventilation (SIMV)

Controlled mechanical ventilation (CMV)

provides full ventilator support by delivering a preset tidal volume and respiratory rate

Continuous mandatory ventilation

- aka Assist control or AC mode

- ventilator delivers a predetermined number of mandatory breaths and simultaneously permits the patient to initiate additional assisted breaths

- when the patient attempts to breathe, the machine actively supports the breath with positive pressure

Hyperventilation

- potential issue of Continuous mandatory ventilation

- px received too many breaths

- results to respiratory alkalosis

Intermittent mandatory ventilation (IMV)

- combination of mechanically assisted breaths and spontaneous breaths

- spontaneous breaths are limited to the tidal volume generated by the patient

Synchronized intermittent mandatory ventilation (SIMV)

- the patient can breathe spontaneously with no assistance from the ventilator on those extra breaths

- This mode is beneficial for preserving respiratory muscle strength and preventing muscular atrophy.

HOLD

High Pitch, Obstruction

Low Sound, Disconnection

mnemonics for MechVent sounds

Respiratory weaning

- process of withdrawing the patient from dependence on the ventilator

- during the process, observe for signs and symptoms of hypoxia

3 phases of respiratory weaning

1. the patient is gradually removed from the ventilator,

2. then from either the ET or tracheostomy tube,

3. and finally from oxygen.

Methods of Respiratory Weaning

- using CPAP

- SIMV mode during mech vent use

- T-piece spontaneous breathing trials

Removal of Tracheostomy tube

considered when the patient can breathe spontaneously; maintain an adequate airway by effectively coughing up secretions, swallow, and move the jaw

FIO2

- Fraction of Inspired Oxygen

- the concentration of oxygen in the gas mixture

- gradually reduced until the PaO2 is in the range of 70 to 100 mm Hg while the patient is breathing room air

70-100 mmHg

normal PaO2 range

Steps of PPE Doning

1. Hand Hygiene

2. Gown

3. Mask

4. Goggles

5. Gloves

Steps of PPE Removal

1. Gloves

2. Goggles

3. Gown

4. Mask

5. Hand Hygiene

Steps of Intubation

!. Preoxyginate for 1 minute

2. Position the patient

3. Laryngoscope (right side of tongue)

4. Insertion of ET Tube

5. Position the ET Tube

6. Inflate the cuff

7. Bag-Mask Ventilation

8. Confirm position by auscultating

NPO or ice chips

status of patient (re: food) for the next few hours following extubation