Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Bilateral diffuse alveolar infiltrates are present with severe hypoxemia Pulmonary capillary wedge pressure (PCWP) is < 18 mm Hg Arterial partial pressure of oxygen/inspired oxygen concentration (PaO2/FiO2) of ≤ 200 mm Hg +++ GENERAL CONSIDERATIONS ++ Acute respiratory distress syndrome (ARDS) is the most severe form of acute lung injury ARDS may be a manifestation of several conditions, such as sepsis, aspiration, hypertransfusion, toxic inhalation, severe nonthoracic trauma, and cardiopulmonary bypass Other incompletely understood causes include high-altitude pulmonary edema, neurogenic pulmonary edema, narcotic overdose, eclampsia, and cardioversion Clinically, one-third of ARDS patients have sepsis The mechanism of lung injury varies, but the common pathway involves elevated pulmonary capillary pressure resulting in pulmonary endothelial damage with increased capillary permeability +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Tachypnea, dyspnea, labored breathing +++ PHYSICAL EXAM FINDINGS ++ Pulmonary rales Hypoxemia, tachycardia +++ DIFFERENTIAL DIAGNOSIS ++ Cardiogenic pulmonary edema (PCWP is typically > 18 mm Hg) Lymphangitic carcinomatosis (PCWP is < 18 mm Hg) Unilateral pulmonary edema after evacuation of large pleural effusion (PCWP is normal) +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ Blood cultures may be positive in sepsis Plasma B-type natriuretic peptide (BNP) may be used to distinguish heart failure and cardiogenic pulmonary edema from noncardiogenic causes +++ IMAGING STUDIES ++ Chest x-ray: – Shows diffuse patchy bilateral infiltrates initially; then confluence with air bronchograms – The costophrenic angles are spared and effusions are unusual – Heart size is normal Echocardiography: shows normal left ventricular function +++ DIAGNOSTIC PROCEDURES ++ Right heart catheterization may be necessary to exclude cardiogenic shock +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ Suspected cardiogenic shock +++ HOSPITALIZATION CRITERIA ++ All patients with ARDS are hospitalized +++ MEDICATIONS ++ Treat the underlying cause if possible Give supplemental oxygen and noninvasive ventilatory support in early stages of acute lung injury Give mechanical ventilatory support with positive end-expiratory pressure and low tidal volumes (6–10 mL/kg) in established ARDS Novel ventilation strategies, including high-frequency ventilation and liquid ventilation, hold promise for improvement of outcomes +++ THERAPEUTIC PROCEDURES ++ Endotracheal intubation is almost always required +++ MONITORING ++ ECG monitoring in hospital as appropriate Routine right-heart catheter monitoring is not recommended +++ DIET AND ACTIVITY ++ Intensive care unit protocol for parenteral nutrition in the critically ill +++ ONGOING MANAGEMENT +++ HOSPITAL DISCHARGE CRITERIA... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.