32.6b Noncardiogenic Pulmonary Edema / Acute Respiratory Disease Syndrome

acute respiratory distress syndrome (ARDS)

① is a rapidly progressing life-threatening condition that adversely affects gas exchange in the lungs, leading to hypoxia.

fluid accumulation in the interstitial space within the lungs

Acute respiratory distress syndrome (ARDS) is a form of pulmonary edema that is caused by ①.

left ventricle

Patients with cardiogenic pulmonary edema have a poorly functioning {①

hydrostatic pressure

fluid acculumulation in the interstitial space

A poorly functioning left ventricle leads to increases in ①

increased vascular permeability

decreased fluid removal from the lung tissue

In patients with ARDS, however, fluid accumulation occurs as the result of ①

severity of the disease

The mortality rate of ARDS is related to the ①

liver and kidneys

Although many patients with ARDS die as the result of respiratory failure, many other patients succumb to failure of several organ systems, including the ①

lung diffusion

ARDS is a disorder of ① that results from increased fluid in the interstitial space.

proper fluid balance in the interstitial space

Each of the underlying conditions cited previously results in the inability to maintain a ①

cardiac arrest, drowning, seizure activity

hypoventilation, high-altitude exposure, environmental toxins

endotoxins released in septic shock

Severe hypotension and significant hypoxemia as the result of ① can cause disruption of the alveolar–capillary membrane.

interstitial edema

Increases in pulmonary capillary permeability, destruction of the capillary lining, and increases in osmotic forces act to draw fluid into the interstitial space and contribute to ①

thickness of the respiratory membrane

Interstitial edema increases the ① and limits diffusion of oxygen.

loss of surfactant

collapse of the alveolar sacs

impairment of gas exchange

In advanced cases, fluid also accumulates in the alveoli, causing ①

pulmonary shunting

Fluid accumulation in the alveoli results in a significant amount of ① with deoxygenated blood returning to the circulation. The result is significant hypoxia.

sepsis

Specific clinical symptoms are related to the underlying cause of ARDS. For example, patients who develop ARDS as the result of ① have symptoms related to their underlying infection.

prolonged hypoxia, head or chest trauma

inhalation of gases, ascent to a high altitude w/o prior acclimation

Determine whether there is a history of ①, all of which can suggest an underlying cause for the respiratory complaints.

gradual decline

Patients with ARDS experience a ① in their respiratory status.

high-altitude pulmonary edema (HAPE)

In rare cases, a seemingly healthy patient has a sudden onset of respiratory failure and hypoxia. Such a presentation is characteristic of patients with ①

noncardiogenic pulmonary edema

Dyspnea, confusion, agitation, fatigue, and reduced exercise activity are often found in patients with ①

orthopnea, paroxysmal nocturnal dyspnea, increased sputum production

Symptoms such as ① are not commonly reported but can be seen.

underlying lung insult

The prominent physical findings are generally those associated with the ①

tachypnea and tachycardia

① are often found in association with ARDS.

crackles (rales)

① are audible in both lungs.

wheezing

① can also be heard if there is any element of bronchospasm.

severe tachypnea

central cyanosis

signs of imminent respiratory failure

① are seen in severe cases.

pulse oximetry

① will demonstrate low oxygen saturations in patients with advanced disease.

decreased lung compliance

In patients requiring ventilatory support, ① will be noted.

more operator force

Decreased lung compliance will require ① to deliver an adequate lung volume.

the patient's underlying medical condition

Specific management of ① is the hallmark of treatment for ARDS.

appropriate antibiotics

removal of the patient from any inciting toxin

Treatment of Gram-negative sepsis includes ①

rapid descent to a lower altitude

Treatment involves a ① in patients with HAPE

upright position

The patient usually tolerates an ① with the legs dangling off the cot or stretcher.

oxygen supplementation

Because the hypoxia seen in ARDS is the result of diffusion defects, ① is often essential for all patients with ARDS.

hypovolema

Establish intravenous access, but provide fluids only if ① exists.

lung secretions

Suctioning ① is often required to maintain airway patency.

positive pressure ventilation

Use ① to support any ARDS patient who demonstrates signs of respiratory failure.

BVM ventilation

Use ① for initial respiratory support while preparing a CPAP device.

ET intubation and mechanical ventilation

Use of CPAP can often avoid the need for ①

positive end-expiratory pressure (PEEP)

①, via CPAP, will help to maintain patency of the alveoli and adequate oxygenation.

diuretics and nitrates

①, which are used in patients with cardiogenic pulmonary edema, are usually not helpful in patients with ARDS.

corticosteroids

A medical director can occasionally order ① for patients with ARDS/noncardiogenic pulmonary edema.

alveolar-capillary membrane

Corticosteroids are thought to stabilize the ①, although clinical studies have not demonstrated any benefit to their use.

cardiac monitoring and pulse oximetry

Maintain ① throughout transport of the patient.

advanced hemodynamic monitoring and mechanical ventilation support

Transport patients to a facility capable of ①