Chapter 3: Management of Patients with Chest and Lower Respiratory Tract Disorders (Part 4)

Acute Respiratory Distress Syndrome

clinical syndrome characterized by a severe inflammatory process causing diffuse alveolar damage that results in sudden and progressive pulmonary edema, increasing bilateral infiltrates on chest x-ray, hypoxemia and unresponsive to oxygen supplementation

Acute Respiratory Distress Syndrome

- initially closely resembles severe pulmonary edema

Arterial hypoxemia that does not respond to supplemental oxygen

characteristic of Acute Respiratory Distress Syndrome

Risk Factors of Acute Respiratory Distress Syndrome

- Aspiration

- COVID-19 Pneumonia

- Drug ingestion and overdone

- Fat or air embolism

- Hematologic disorders

- Shock

Risk Factors of Acute Respiratory Distress Syndrome

- Localized infection

- Major surgery

- Metabolic disorders

- Prolonged inhalation of high concentrations of oxygen, smoke, or corrosive substances

- Sepsis

- Trauma

Intercostal retractions, crackles

may be present in Acute Respiratory Distress Syndrome

Management of Acute Respiratory Distress Syndrome

- identification and treatment of the underlying condition

- ET intubation and MV, suctioning, nebulization

- (Positive end expiratory pressure (PEEP)

Positive end expiratory pressure (PEEP)

- a pressure applied by the ventilator at the end of each breath to ensure that the alveoli are not so prone to collapse

- 'recruits' the closed alveoli in the sick lung and improves oxygenation

- a critical part of the treatment of ARDS

- helps increase functional residual capacity and reverse alveolar collapse by keeping the alveoli open, resulting in improved arterial oxygenation and a reduction in the severity of the V./Q. imbalance

V./Q. imbalance

the most serious complication and most frequent cause of death among patients with COVID-19

Pulmonary Hypertension

characterized by elevated pulmonary arterial pressure greater than 25 mmHg at rest and greater than 30 mmHg with exercise and secondary right heart ventricular failure

11-20 mmHg

normal range for pulmonary arterial pressure

clinical recognition

- since pulmonary pressure cannot be measure indirectly, this becomes the only indicator of PH

- not clinically evident until progression

Pulmonary Hypertension

- blood vessels in the lungs are narrowed, blocked or destroyed

- Blood pressure in the lung arteries goes up

- heart must work harder to pump blood through the lungs

-The extra effort eventually causes the heart muscle to become weak and fail--leading to right ventricular hypertrophy (enlargement and dilation) and failure

Causes of Pulmonary Hypertension

- stenosis

- clots

- blockage

- thickened walls

Signs and Symptoms of Pulmonary Hypertension

- dyspnea with exertion and eventually at rest

- substernal chest pain

- weakness, fatigue, syncope, occasional hemoptysis

- signs of right-sided heart failure

signs of right-sided heart failure

- peripheral edema

- ascites

- distended neck veins

- liver engorgement

- crackles

- heart murmur

Echocardiogram

- used to estimate the pulmonary artery systolic pressure and to assess right ventricular size, thickness, and function

- can also evaluate the right atrial size, left ventricular system, and diastolic function as well as valve function

Right heart catheterization

confirmatory test for pulmonary hypertension

mean pulmonary artery pressure greater than 25 mmHg

confirms pulmonary hypertension

Management for Pulmonary Hypertension

- diuretics

- oxygen

- anticoagulation

- digoxin

- exercise training

- calcium channel blockers

- phosphodiesterase-5 inhibitors

- Soluble guanylate cyclase stimulants

Sildenafil

promotes pulmonary vasodilation--also used to treat erectile dysfunction

Riociguat

- Soluble guanylate cyclase stimulant

- newly FDA approved for use in PH

- Contraindicated for patients with Liver and Kidney disease

Surgical Management for Pulmonary Hypertension

- bilateral lung or heart-lung transplantation

- Atrial septostomy

Chest Trauma

- Blunt Trauma

- Flail Chest

- Pulmonary Contusion

Blunt Trauma

- most common causes: motor vehicle crashes, fall

- Injuries to the chest are often life-threatening and result in one or more of the following pathologic states: Hypoxemia, Hypovolemia and Cardiac Failure

Assessment for Blunt Trauma

- inspect airway, thoracic area, neck veins and breathing difficulty

- symmetric chest movements, breath sounds, open wounds

Flail Chest

- occurs when three or more adjacent ribs (multiple contiguous ribs) are fractured at two or more sites, resulting in free-floating rib segments

- chest wall loses stability, causing respiratory impairment and usually severe respiratory distress.

Supportive Management for Flail Chest

- Ventilatory Support

- Clearing Secretions

- Controlling pain

ET to MV

management for severe flail chest

Chest wall stabilization plating system

- surgical management for flail chest

- done Within the first 72 hours of injury

- decreased bleeding, less inflammation, and reduced chest wall deformities

Pulmonary Contusion

- defined as damage to the lung tissues resulting in hemorrhage and localized edema

- cited as the most common potentially life-threatening chest injury

Signs and Symptoms of Pulmonary Contusion

- Tachypnea

- tachycardia

- decreased breath sounds

- blood tinged secretions

- hypoxemia (increased agitation or combative irrational behavior, may be signs of hypoxemia)

Pulse oximetry and ABG

diagnostic tests for pulmonary contusion

Management for Pulmonary Contusion

- maintaining an airway

- provide adequate 02

- control pain

- fluid intake to monitor to avoid hypervolemia

Management for Severe Pulmonary Contusion

- ET to MV

- Diuretics

- Fluid restriction

- Antibiotic therapy

negative pressure/subatmospheric

- normal pressure in the pleural space

- required to maintain lung inflation.

Pneumothorax

occurs when the parietal or visceral pleura is breached and the pleural space is exposed to positive atmospheric pressure

Types of pneumothorax

- simple

- traumatic

- tension

simple pneumothorax

- spontaneous

- occurs when air enters the pleural space through a breach of either the parietal or visceral pleura

- Most commonly, this occurs as air enters the pleural space through the rupture of a bleb or a bronchopleural fistula

causes of bleb

- smoking

- using cannabis

- emphysema

bronchopleural fistula

a communication between the pleural space and the bronchial tree

Traumatic Pneumothorax

- occurs when air escapes from a laceration in the lung itselfand enters the pleural space or from a wound in the chest wall

- may result from rib fractures, stab wounds, gunshot wounds or any invasive thoracic procedures

- often accompanied by hemothorax (Hemopneumothorax)

Open pneumothorax

- wound in the chest wall is large enough to allow air to pass freely in and out of the thoracic cavity with each attempted respiration

- EMERGENCY

- Stoppingthe flow of air through the opening in the chest wall is a lifesaving measure.

Tension Pneumothorax

the air that enters the chest cavity with each inspiration is trapped; it cannot be expelled during expiration through the air passages or the opening in the chest wall.

Pathophysiology of Tension Pneumothorax

air cannot escape

↓

positive pressure is increased

↓

Lung collapsed

↓

Heart, great vessels, trachea to shift toward the unaffected side of the chest

↓

Decreased venous return

↓

Decreased cardiac output

↓

Impaired peripheral circulation

Management of Tension Pneumothorax

goal: to evacuate the air or blood from the pleural space

- chest tube insertion/drainage

- thoracentesis

- 02 to treat hypoxemia

Chest Drainage Systems

- close drainage system, used to re-expand the involved lung and to remove excess air, fluid, and blood

- have a suction source, a collection chamber for pleural drainage, and a mechanism to prevent air from reentering the chest with inhalation