Acute respiratory distress syndrome

The patient may not exhibit respiratory symptoms for

1 or 2 days after the initial injury. Without treatment, ARDS will progress in four phases.

Endotracheal tube complications: Type of complications

Laryngeal ulceration Tracheal malacia Tracheal stenosis Tracheal ulceration

Nurses are a vital link in identifying subtle changes in their patients. It is necessary to look at

trends, not just what is happening right now. The nurse needs to report to the provider any change in patient status, laboratory values, or response to treatment.

Management of ARDS involves treating the

underlying cause or injury. In addition to respiratory support, the nurse must work with other health care professionals and departments to provide care for the patient. This may include the respiratory therapist, physical therapist, physicians of different specialties, and the providers in the intensive care unit. The nurse may need to arrange consultations with the dietician to discuss nutritional needs or the chaplain to provide support to the patient or family. The patient may also need care after discharge, requiring the social worker or case manager to become involved in discharge planning.

The nurse works with the interdisciplinary team to correct hypoxemia and prevent further complications after a diagnosis of ARDS. The nurse must understand the

underlying conditions that contribute to a diagnosis of ARDS. The underlying condition must be treated, and the patient must be closely monitored for signs of improvement or decline.

The progression of ARDS

varies. Some patients survive the acute phase of lung injury, and complete recovery occurs within a few days. Others progress to the fibrotic phase, requiring long-term mechanical ventilation, with a poor chance of survival.

No specific test can be used to diagnose ARDS. Rather, diagnosis is made based on

vital signs, clinical manifestations, and findings on a chest x-ray. The nurse knows that careful assessment of patients at risk for ARDS can be instrumental in rapid diagnosis and initiation of treatment.

Clinical manifestations of ARDS depend on the

cause and the other body systems involved.

The nurse is caring for a patient with acute respiratory distress syndrome (ARDS) who is having difficulty breathing and an oxygen saturation of 85%. The patient's spouse is at the bedside and asks why the patient is having difficulty breathing. What is the best response by the nurse?

"Your spouse has refractory hypoxemia, which is low blood oxygen that is not being resolved with the therapies we are trying."

Summary

ARDS is triggered by an injury to the lungs such as trauma, pneumonia, embolism, aspiration and most frequently, sepsis. Initially, the patient may not have respiratory symptoms. However, the disease can progress rapidly from mild symptoms, such as dyspnea and cough, to profound respiratory distress requiring mechanical ventilation. Death can occur as a result of MODS or other complications. The nurse must be aware of risk factors and clinical manifestations of this condition so that the health care team can intervene early and minimize severity. Nursing interventions focus on restoration of normal respiratory function, maintaining fluid and nutritional balances, and aggressive hemodynamic monitoring.

Complications may develop as a result of

ARDS itself or its treatment. The nurse must be aware of potential complications associated with ARDS in order to monitor for and inform the health care provider of any changes in the patient's clinical status.

The Common Risk Factors For Development Of ARDS: Indirect lung injury: Less common causes

Acute pancreatitis Cardiopulmonary bypass Disseminated intravascular coagulation Opioid drug overdose (eg, heroin) Severe head injury Shock states Transfusion-related

Introduction

Acute respiratory distress syndrome, or ARDS, is a serious respiratory condition that has a mortality rate of approximately 50%. It is seen most frequently in patients with respiratory or chest trauma; however, the most common risk factor is the presence of sepsis. Symptoms vary depending on the severity of the infection, but they can rapidly progress to profound respiratory failure and multiple organ dysfunction syndrome (MODS), which is the most common cause of death associated with ARDS. It is crucial for nurses to understand the pathophysiology and presentation of ARDS so they can rapidly intervene when an at-risk patient develops the condition.

The nurse is receiving a report on a patient diagnosed with acute respiratory distress syndrome (ARDS). The patient is intubated and mechanically ventilated. On assessment, the nurse notes crackles in the lungs, poor skin turgor, and decreased capillary refill. The patient is receiving nothing by mouth (NPO) with normal saline solution infusing at 100 mL/hr. Urine output was 100 mL over the last 4 hours. Which action should the nurse perform first?

Administer dopamine as ordered. A patient with a urine output of less than 30 mL/hr and ARDS is likely experiencing decreased cardiac output. A medication such as dopamine or dobutamine is needed to support cardiac output and function.

Etiology ARDS

An exact cause for damage to the alveolar-capillary membrane is not known. However, many changes are thought to be caused by stimulation of the inflammatory and immune systems, which attracts neutrophils to the pulmonary interstitium. The neutrophils cause a release of biochemical, humoral, and cellular mediators that produce changes in the lungs, including increased pulmonary capillary membrane permeability, destruction of elastin and collagen, formation of pulmonary microemboli, and pulmonary artery vasoconstriction.

Hematologic complications: Type of complications

Anemia Disseminated intravascular coagulation Thrombocytopenia Venous thromboembolism

Progression 3

As ARDS progresses, profound respiratory distress requires endotracheal intubation and positive pressure ventilation (PPV). The chest x-ray reveals whiteout or white lung as consolidation and coalescing infiltrates pervade the lungs, leaving few recognizable air spaces. Pleural effusions may be present. The patient may have severe hypoxemia and hypercapnia. Metabolic acidosis, with symptoms of target organ or tissue hypoxemia, may develop if therapy is not promptly started.

Progression 2

As ARDS progresses, symptoms worsen because of increased fluid accumulation in the lungs and decreased lung compliance. The nurse may observe: Tachycardia Diaphoresis Changes in sensorium with decreased mentation Cyanosis Pallor Scattered to diffuse crackles and rhonchi on auscultation Hypoxemia, despite administration of supplemental oxygen, a hallmark of ARDS Hypercapnia, signifying respiratory muscle fatigue and hypoventilation

Infection: Type of complications

Catheter-related infection (eg, central and peripheral intravenous [IV] catheters, urinary catheters) Sepsis

The Common Risk Factors For Development Of ARDS: Direct lung injury: Less common causes

Chest trauma Embolism: fat, air, amniotic fluid, thrombus Inhalation of toxic substances Near drowning Oxygen toxicity Radiation Pneumonitis

A patient is being evaluated for acute respiratory distress syndrome (ARDS). On assessment of the patient, the nurse notes tachypnea, dyspnea, and confusion. For which test would the nurse expect to prepare the patient to confirm the diagnosis of ARDS?

Chest x-ray

Phase: Fibrotic Timeframe: 2-3 weeks after lung injury Events:

Chronic or late phase of ARDS Lung completely remodeled by collagenous and fibrous tissues Diffuse scarring and fibrosis resulting in decreased lung compliance and decreased surface area for gas exchange Pulmonary hypertension resulting from fibrosis

Progression 4 and final stages

Complications may develop as a result of ARDS itself or its treatment. The primary cause of death in ARDS is MODS, often accompanied by sepsis. The vital organs most commonly affected by MODS are the kidneys, liver, and heart.

Maintenance of nutrition and fluid balance is challenging in the patient with ARDS. The nurse should:

Consult with a dietitian to determine optimal caloric needs. Provide enteral or parenteral feedings as ordered to meet the high-energy requirements of these patients. Enteral formulas enriched with omega-3 fatty acids may improve the clinical outcomes of patients with ARDS. Monitor hemodynamic parameters (eg, CVP, stroke volume variation), daily weights, and intake and output to assess the patient's fluid status. Controversy exists as to the benefits of fluid replacement with crystalloids versus colloids. Critics of colloid replacement believe that proteins in colloids may leak into the pulmonary interstitium, increasing the movement of fluid into the alveoli. Advocates of colloid replacement believe that colloids help keep fluid from leaking into the alveoli.

A nurse is caring for a patient with acute respiratory distress syndrome (ARDS). At the start of the shift, the nurse finds that the patient has been placed in a prone position. Functional saturation of oxygen (SpO2) is 93%. How does the nurse respond?

Continue to monitor per hospital protocol.

CNS and Psychological complications: Type of complications

Delirium Sleep deprivation Posttraumatic stress disorder

A nurse is caring for a patient with severe acute respiratory distress syndrome (ARDS). The patient had an arterial catheter placed in the morning. The nurse observed a decrease in cardiac output and blood pressure after vital signs were measured in the afternoon. What medication does the nurse anticipate administering?

Dopamine

Cardiovascular complications: Type of complications

Dysrhythmias Decreased cardiac output

mechanical ventilation

Endotracheal intubation and PPV are needed when hypoxemia does not respond to other treatments.Use of positive end-expiratory pressure (PEEP) keeps lungs partially expanded and prevents total collapse of alveoli. If hypoxemic failure persists, alternative modes and therapies may be used. These include airway pressure release ventilation, pressure-control inverse-ratio ventilation, high-frequency ventilation, and permissive hypercapnia (low tidal volumes that allow the positive pressure of carbon dioxide in arterial blood (PaCO2) to increa

A nurse is caring for a patient who is suspected of developing acute respiratory distress syndrome (ARDS). The patient is receiving oxygen at 15 L /min through a nonrebreather mask while awaiting further evaluation. What should the nurse implement for this procedure to be most effective?

Ensure the mask fits snuggly on the patient's face.

Renal complications: Type of complications

Hypermetabolic state with dramatically increased nutrition requirements Acute kidney injury

A patient is diagnosed with acute respiratory distress syndrome (ARDS) two days after a crushing chest injury during a motor vehicle collision. Which statement best explains the cause of the patient's worsening symptoms?

Inflammatory mediators are released.

Phase: Reparative/Proliferative Timeframe: 1-2 weeks after lung injury Events:

Influx of granulocytes, monocytes, and lymphocytes Fibroblast proliferation

Phase: Injury/Exudative Timeframe: 1-7 days after lung injury Events:

Interstitial and alveolar edema (noncardiogenic pulmonary edema) Atelectasis

Fluid Balance

Maintenance of nutrition and fluid balance is challenging in the patient with ARDS. Parenteral or enteral feedings are started to meet the high-energy requirements of these patients. Enteral nutrition is usually started before parenteral nutrition because of the increased risk of infection associated with parenteral means and the need to preserve gastrointestinal (GI) function. Increasing pulmonary capillary permeability results in fluid in the lungs and causes pulmonary edema. Fluid restriction is usually prescribed, and diuretics are used as necessary. At the same time, the patient may be volume depleted and therefore prone to hypotension and decreased cardiac output from mechanical ventilation and PEEP. Monitor fluid status carefully.

A patient with aspiration pneumonia presents with a heart rate of 128 beats/min, respiratory rate of 32 breaths/min, blood pressure of 148/92 mm Hg, and functional saturation of oxygen on 88% on room air. The patient reports shortness of breath (SOB) and fatigue. Which blood test would the nurse anticipate first?

Measurement of arterial blood gases (ABGs)

Assessment parameters for ARDS are very similar to those for ARF. The nurse will:

Monitor patient's respiratory status for decline Assess perfusion and oxygenation Watch for signs of end-organ damage Observe patient's urine output for signs of kidney involvement (Low hourly output can also indicate decreasing cardiac output.

Case Study: The Patient with Acute Respiratory Distress Syndrome

Mr. Whaley is a 55-year-old man who recently had bowel surgery but developed ARF postoperatively. Subjective DataMr. Whaley is intubated and receiving mechanical ventilation. Mr. Whaley is sedated and paralyzed and is unable to communicate.His wife and two adult children are at the bedside and voicing concerns and questions regarding his progress. Objective Data Physical Assessment General: Sedated, paralyzed, well-nourished man; head of bed elevated 45 degrees; skin cool with moderate diaphoresis Respiratory: No accessory muscle use, retractions, or paradoxical breathing; respiratory rate 18 breaths/min and in phase with ventilator; SpO2 85%; fine crackles at lung bases Cardiovascular: BP 100/60 mm Hg Gastrointestinal: Surgical dressing dry and intact; colostomy draining serosanguinous fluid Urologic: Indwelling bladder catheter draining concentrated urine less than 30 mL/hr Diagnostic FindingsABGs: pH 7.15, PaO2 56 mm Hg, PaCO2 57 mm Hg, bicarbonate level 16 mEq/L, oxygen saturation 86%PaO2/FiO2 ratio <200Chest x-ray: new bilateral, scattered interstitial infiltrates

A patient with pneumonia reports increased sweating, persistent coughing, shortness of breath and palpitations. The nurse notes tachycardia and cyanosis. The patient is receiving oxygen via a nasal cannula at 2 L/min. Which action would the nurse take next?

Notify the health care provider Inform the respiratory therapist

Respiratory complications: Type of complications

Oxygen toxicity Pulmonary barotrauma (eg, pneumothorax, pneumomediastinum, subcutaneous emphysema) Pulmonary emboli Pulmonary fibrosis Ventilator-associated pneumonia

The overall goals for the patient with ARDS include maintaining a partial pressure of oxygen in arterial blood (PaO2) of at least 60 mm Hg and adequate lung volume to maintain normal pH. A patient recovering from ARDS will exhibit:

PaO2 within normal limits for age or baseline values on room air Oxygen saturation in arterial blood (SaO2) greater than 90% A patent airway Clear lungs on auscultation

Gastrointestinal complications: Type of complications

Paralytic ileus Pneumoperitoneum Stress ulceration and hemorrhage

Hemodynamic Monitoring

Patients receiving PPV and PEEP frequently experience decreased cardiac output. Hemodynamic monitoring is essential to see trends, detect changes, and adjust therapy as needed. An arterial catheter, also known as an A-line, is inserted for continuous monitoring of blood pressure (BP) and sampling of blood for determination of ABG values. Use of inotropic drugs, such as dobutamine or dopamine, may also be necessary.

Maintaining Cardiac Output and Tissue Perfusion

Patients receiving PPV and PEEP frequently experience decreased cardiac output. When caring for a patient with decreased CO, the nurse should give IV fluids and administer medications (usually dopamine or dobutamine) as ordered. It is important for the nurse to actively monitor blood pressure and the other vital signs. Hemodynamic monitoring (eg. central venous pressure [CVP], cardiac output, central venous oxygen saturation, venous oxygen saturation) via central venous or pulmonary artery pressure, or arterial pressure-based cardiac output monitoring, is essential. If the cardiac output falls, it may be necessary to administer crystalloid fluids or colloid solutions or to lower PEEP. Packed red blood cells are used to increase hemoglobin and thus the oxygen-carrying capacity of the blood. The hemoglobin level is usually kept around 9 to 10 g/dL (90 to 100 g/L) with a functional oxygenation saturation (SpO2) of 90% or more (when PaO2 is greater than 60 mm Hg).

A nurse is assessing a patient with acute respiratory distress syndrome (ARDS) who is intubated and receiving mechanical ventilation. Arterial blood gases reveal a partial pressure of oxygen in arterial blood (PaO2) of 55 mm Hg. The nurse knows that the respiratory therapist may recommend which types of treatment?

Permissive hypercapnia Airway pressure release ventilation Pressure-control inverse-ratio ventilation

A patient has developed acute respiratory distress syndrome (ARDS) after aspiration and is now arriving at the hospital by ambulance. The patient is hyperventilating and has been receiving oxygen at a rate of 15 L/min via a simple facemask. Which provider order would the nurse anticipate?

Prepare for intubation and mechanical ventilation with positive end-expiratory pressure (PEEP). Intubation and mechanical ventilation with PEEP will be required because the patient is still hyperventilating even after receiving a large amount oxygen. PEEP should be used to help the patient breathe.

A patient with acute respiratory distress syndrome (ARDS) secondary to a chest injury has crackles in the bilateral posterior lung fields. The nurse also notes tachycardia, delayed capillary refill, decreased urine output, and the following arterial blood gas (ABG) results: pH 7.56, PaO2 51, PaCo2 28, HCO3 24, SaO2 76%. Which provider order would the nurse implement first?

Prepare the patient for mechanical ventilation.

The nurse is caring for a patient diagnosed with acute respiratory distress syndrome (ARDS). On assessment, the nurse notes crackles in the lungs and peripheral edema. Which nursing assessments are appropriate for the nurse to obtain?

Skin integrity Intake/output oxygen saturation

The nurse is caring for a patient with acute respiratory distress syndrome (ARDS) secondary to sepsis. The patient is receiving kinetic therapy. The nurse should ensure that the nursing assistant performs which intervention?

Turns the patient every 2 hours.

The Common Risk Factors For Development Of ARDS: Indirect lung injury: Common causes

Sepsis (especially gram-negative infection) Severe massive trauma

The Common Risk Factors For Development Of ARDS: Direct lung injury: Common causes

Sepsis (most common cause) Aspiration of gastric contents or other substances Viral or bacterial pneumonia

The nurse knows that patients with which diagnoses are at risk of developing acute respiratory distress syndrome (ARDS)?

Septic shock Severe head injury Amniotic fluid embolus

ARDS is a sudden and progressive form of acute respiratory failure (ARF). In this condition, the alveolar-capillary membrane becomes damaged and more permeable to intravascular fluid, leading the alveoli to fill with fluid. This results in:

Severe dyspnea Hypoxemia refractory to supplemental oxygen Reduced lung compliance Diffuse pulmonary infiltrates More than 150,000 cases of ARDS are reported in the United States annually, with mortality around 50%. Patients with both ARDS and gram-negative septic shock have a mortality rate of approximately 70% to 90%.

positioning

Some patients with ARDS are able to breathe better in a prone position. Patient is placed in a face-down position anywhere from 12 to 20 hours. This improves oxygenation. Consider providing kinetic therapy, which provides continuous, slow, side-to-side turning of the patient by rotating the actual bed frame. Maintain the lateral movement of the bed, at least 40 degrees to each side (total arc of at least 80 degrees), for 18 of every 24 hours; however, the nurse will still need to turn the patient every 2 hours to prevent skin breakdown. Stimulates postural drainage, helps mobilize pulmonary secretions, and improves ventilation/perfusion ratio.

The nurse is teaching a nursing student about acute respiratory distress syndrome (ARDS). The student asks how to recognize symptoms of the disease as it progresses. In which order does the nurse describe the symptoms?

Tachypnea and cough Decreased mental status Respiratory distress Decreased urine output

The nurse is concerned about which findings when assessing Mr. Whaley at the start of a shift?

Urine output of <30 mL/hr Mr. Whaley's chest x-ray results Partial arterial oxygen tension (PaO2) of 56 mm Hg

Progression 1

The patient may exhibit:TachypneaDyspneaCoughRestlessnessConfusion Normal breath sounds or fine, scattered crackles may be heard on chest auscultation. Arterial blood gases (ABGs) will indicate mild hypoxemia and respiratory alkalosis. Chest x-ray may reveal normal findings or show evidence of minimal scattered interstitial infiltrates.

Pathophysiology ARDS

The three phases of ARDS are the injury phase, the reparative phase, and the fibrotic phase.

A nurse is caring for a patient with acute respiratory distress syndrome (ARDS) and notes a hemoglobin of 7 g/dL. The nurse anticipates what order?

Transfusion of packed red blood cells (RBCs)

oxygen therapy

Use a nasal cannula or facemask with high-flow systems that deliver higher oxygen concentrations. Give the lowest concentration of oxygen that results in a PaO2 of 60 mm Hg or greater. When FiO2 exceeds 60% for more than 48 hours, the risk for oxygen toxicity is increased. Patients with severe ARDS and refractory hypoxemia need intubation with mechanical ventilation.

ARDS will progress in how many phases

four

Nursing care is focused on treating

hypoxemia and preventing further complications from poor tissue perfusion. The nurse should be aware of the pathophysiology related to decreasing cardiac output in patients receiving PEEP so appropriate monitoring can be performed.

Findings that support a diagnosis of ARDS are

refractory hypoxemia with a partial arterial oxygen tension/fractional concentration of oxygen in inspired gas (PaO2/FiO2) ratio <200, detection of new bilateral interstitial or alveolar infiltrates on chest x-ray, and pulmonary artery occlusion pressure of 18 mm Hg or less with no evidence of heart failure.