Life-Threatening Pulmonary Disorders
Acute and chronic respiratory conditions can rapidly deteriorate into situations that require immediate intervention to save the client's life. Some of these conditions, such as flail chest, are related to traumatic injury of the chest. Others, such as pulmonary embolus and acute respiratory distress syndrome, are related to a variety of causes including fractures. In this section, we will discuss the most common life-threatening pulmonary disorders and the nursing care related to those clients.
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome, commonly known as ARDS or noncardiogenic pulmonary edema, occurs mostly in otherwise healthy persons. ARDS can be the result of intrinsic factors (such as anaphylaxis, sepsis, or pulmonary emboli) or extrinsic factors (such as aspiration or inhalation injury). ARDS can also occur as a complication from abdominal or thoracic surgery. The client with ARDS develops increased extravascular lung fluid that contains a high concentration of protein although the interstitial tissue remains relatively dry. ARDS can be diagnosed by a chest x-ray that reveals emphysematous changes and infiltrates that give the lungs a characteristic appearance described as ground glass. Assessment of the client with ARDS reveals:
- Hypoxia (decreased tissue oxygenation)
- Suprasternal and intercostal retractions
- Presence of crackles (rales) or rhonchi
- Diminished breath sounds
- Refractory hypoxemia (low levels of oxygen in the blood despite supplemental oxygen delivered at high concentrations)
Nursing care of the client with ARDS involves the following:
- Maintaining endotrachial intubation and mechanical ventilation with positive end expiratory pressure (PEEP) or continuous positive airway pressure (CPAP). The goal of ventilation is to maintain a PaO2 greater than 60 mm Hg or O2 saturation level greater than 90% at the lowest possible FiO2 setting.
- Monitoring of arterial blood gases.
- Providing for nutritional needs either by tube feeding or hyperalimentation (clients with ARDS require 35–45 kcal/kg per day).
- Maintaining fluid volume to maintain adequate cardiac output and tissue perfusion.
- Monitoring of pulmonary artery wedge pressure (assesses fluid status and monitors for the development of pulmonary hypertension).
- Frequent change in position: placement in high Fowler's position. or use of specialized beds to minimize consolidation of infiltrates in large airways. Research has indicated that some clients with ARDS benefit from being placed in a prone position, however the nurse should carefully assess the client's respiratory effort before putting the client flat or in a head-down position.
- Preventing sepsis, pneumonia, and multisystem organ dysfunction.
- Use of low-molecular-weight heparin to prevent thrombophlebitis and possible pulmonary embolus or disseminated intravascular coagulation.
- Investigational therapies include the use of mediators (vitamins C and E, aspirin, interleukin, prostacyclin), nitric oxide, and surfactant replacement.
Nursing Care of the Client Requiring Mechanical Ventilation
The client with ARDS has severe problems with maintaining adequate gas exchange, therefore mechanical ventilation is usually required. Nursing care of the client requiring mechanical ventilation includes a general understanding of the type of ventilator and modes of control being used as well as interventions to support the client's physical and psychological well-being. This section begins with a review of mechanical ventilation followed by nursing interventions for the client who is ventilator dependent.
Indications for mechanical ventilation are as follows:
- PaO2 < 50 mm Hg with FiO2 > 0.60
- PaO2 > 50 mm Hg but a pH < 7.25
- Respiratory rate > 35 breaths per minute
- Vital capacity < 2 times tidal volume
There are two basic types of ventilators:
- Negative-pressure ventilators: Work by changing pressures in the chest cavity rather than by forcing air directly into the lungs. Negative pressure ventilators such as the poncho or body wrap are used for clients with neuromuscular disease and chronic obstructive pulmonary disease. An artificial airway is not needed.
Positive-pressure ventilators: Inflate the lungs by exerting positive pressure on the airway, which forces the alveoli to expand during inspiration. In most instances an endotracheal tube or tracheostomy is needed. Postive-pressure ventilators are classified according to the mechanism that ends inspiration and begins expiration. Positive-pressure ventilators are classified as pressure-cycled, time-cycled, flow-cycled, or volume-cycled. Key features of these as follows:
- Pressure-cycled ventilators push air into the lungs until a preset airway pressure is obtained. Pressure-cycled ventilators are sometimes used for respiratory therapy or for the client just after surgery.
- Volume-cycled ventilators push air into the lungs until a preset volume has been delivered. Tidal volume remains constant. Set pressure limits prevent excessive pressure from being exerted on the lungs.
- Time-cycled ventilators push air into the lungs until a preset time has been reached. Tidal volume and pressure vary according to the client's needs.
- Flow-cycled ventilators push air into the lungs until a preset flow rate is achieved during inspiration.
The controlling modes of ventilators are as follows:
- Controlled: The machine ventilates according to set tidal volume and respiratory rate. The client's spontaneous respiratory effort is blocked.
- Assist controlled: A preset volume of oxygen is delivered at a preset rate, but the client can trigger ventilations with negative inspiratory effort.
- Synchronized intermittent mandatory: A preset minimum number of respirations are delivered to the client, but the client can also take spontaneous breaths.
General guidelines for initial ventilator settings are as follows:
- Set the tidal volume required (10–15 mL/Kg).
- Adjust to the lowest concentration of O2 to maintain a PaO2 of 80–100 mm Hg.
- Set the mode according to doctor's order.
- For assist controlled mode, adjust sensitivity so that the client can trigger the ventilator with minimal effort.
- Record minute volume; measure PaO2, PaCO2, and pH every 20 minutes of continuous mechanical ventilation.
- Adjust settings according to the results of arterial blood gases to maintain normal levels or levels prescribed by doctor.
- If the client becomes confused or "fights" the ventilator unexpectedly, assess for hypoxemia and manually ventilate with resuscitation device and 100% oxygen.
Nursing Care of the Client Who Is Ventilator Dependent
Nursing interventions for the client who is ventilator dependent are as follows:
- Explain the purpose of the ventilator. Clients in ICU may become confused and need repeated explanations and reassurance.
- Assess vital signs and breath sounds every 30–60 minutes.
- Assess breathing pattern in relation to ventilation cycle to determine if the client is tolerating the ventilator.
- If an endotracheal tube is used, make sure that it is taped securely in place.
- Monitor pulse oximetry and arterial blood gases.
- Suction when needed, and observe the color and amount of respiratory secretions. Guidelines for performing endotracheal suctioning are given in the sidebar that follows.
- Provide the client with a means of communication such as Magic Slate or writing paper.
- Keep the call light within reach of the client.
Pulmonary embolus (PE) refers to the obstruction of the pulmonary artery or one of its branches by a clot, fat, or gaseous substance. Clots can originate anywhere in the body, but are most likely to migrate from a vein deep in the legs, pelvis, kidney, or arms. Fat embolus is associated with fractures of the long bones, particularly the femur. Air embolus, which is less common, can occur during the insertion or use of central lines. Amniotic embolus can be a complication of amniocentesis or abortion and is associated with a very high mortality rate Septic embolus can result from pelvic abscesses, damaged heart valves, osteomyelitis, infected intravenous catheters, or nonsterile injections of illegal drugs.
Pulmonary embolus affects approximately 500,000 people in the United States annually; therefore, prevention of PE should be a major concern for nurses. The following steps can significantly reduce the incidence of pulmonary embolus:
- Ambulate postoperative clients as soon as possible.
- Apply antiembolism and pneumatic compression stockings.
- Avoid pressure beneath the popliteal space.
- Check the status of peripheral circulation (do not perform Homans' sign because doing so might dislodge any clots that are present).
- Change the client's position every two hours.
- Check IV sites for signs of heat, redness, and swelling as well as blood return.
- Avoid massaging or compressing leg muscles.
- Teach client not to cross the legs.
- Encourage smoking cessation.
Common risk factors for the development of pulmonary embolus include immobilization, fractures, trauma, and history of clot formation. Situations, such as air travel that require prolonged sitting can also contribute to clot formation, particularly in those who are elderly or debilitated. Conditions associated with identified risk factors are smoking, pregnancy, estrogen therapy, use of oral contraceptives, cancer of the lung or prostate, obesity, thrombocytopenia, advanced age, atrial fibrillation, presence of artificial heart valves, sepsis, and congestive heart failure.
Symptoms of a pulmonary embolus depend on the size and location of the clot or undissolved matter. Symptoms generally include the following:
- Pleuritic chest pain
- Low-grade fever
- Hemoptysis (due to pulmonary infarction)
- Transient changes in T wave and S-T segments
- Sense of apprehension
- Petechiae over the chest and axilla (associated with development of DIC [disseminated intravascular coagulation])
- Distended neck veins (indicates right ventricular failure)
Diagnostic tests to confirm the presence of pulmonary embolus include chest x-ray, pulmonary angiography, ventilation-perfusion lung scan, and ECG to rule out myocardial infarction. Chest x-ray findings are often normal or can reveal pulmonary infiltration at the site of the embolus. Negative lung scan rules out the presence of pulmonary embolus. Pulmonary angiography, the most specific diagnostic test for ruling out pulmonary embolus, is used when results of the lung scan are inconclusive.
Management of the client with a pulmonary embolus includes
- Placing the client in an upright sitting position (high Fowler's position)
- Administering oxygen via mask
- Giving medication for chest pain
- Using thrombolytics (streptokinase, urokinase, tPA /anticoagulants [heparin, warfarin sodium])
Antibiotics are indicated for those with septic emboli. Surgical management using umbrella-type filters is indicated for those who cannot take anticoagulants as well as for client who have recurrent emboli while taking anticoagulants. Clients receiving anticoagulant therapy should be observed for signs of bleeding. The protime (PT), International normalized ratio (INR), and partial thromboplastin time (PTT) are three tests used to track the client's clotting time.
Pneumothorax occurs when the pleural space is exposed to positive atmospheric pressure. Normally the pressure in the pleural cavity is negative or subamospheric. It is this negative pressure that keeps the lungs inflated. When either the parietal or visceral pleura is breached, air enters the pleural cavity and increases the intrathoracic pressure. This results in a collapse of a portion of the lung.
There are three classifications of pneumothorax:
- Spontaneous pneumothorax: A non–life-threatening condition that can result from the rupture of a bleb, or blister, on the surface of the visceral pleura or from chronic obstructive pulmonary disease. Blunt chest trauma and penetrating chest wounds are the main causes of traumatic and tension pneumothorax.
- Traumatic pneumothorax: Usually results from blunt trauma to the chest and is classified as either an open pneumothorax (outside air enters the pleural space) or a closed pneumothorax (air from the lung enters the pleural space). Both closed traumatic pneumothorax and tension pneumothorax are life-threatening emergencies that require early detection and treatment.
- Tension pneumothorax: Results from an air leak in the lung or chest wall that leads to collapse of the lung. Air enters the pleural space with each inspiration and does not exit during expiration. Air accumulation in the pleural space compresses blood vessels and decreases venous return. The result is reduced cardiac filling and decreased cardiac output. In addition to blunt chest trauma, tension pneumothorax can result from complications of mechanical ventilation with positive end expiratory pressure (PEEP) and insertion of central venous catheters.
Assessment of the client with a pneumothorax can reveal
- Reduced breath sounds on the affected side
- Hyperresonance on percussion of the chest
- Prominence of the affected side of the chest
- Tracheal deviation away from (closed pneumothorax) or toward (open pneumothorax) the affected side
- Tachypnea, respiratory distress, or cyanosis
- Pleuritic pain
- Subcutaneous emphysema in some cases
- Distended neck veins in some cases
Chest tubes are inserted after confirming the condition by chest x-ray. The initial treatment of tension pneumothorax is the insertion of a large bore needle at the second intercostal space, mid-clavicular line on the affected side followed by insertion of chest tubes connected to a water-sealed chest drainage system.
Hemothorax, an accumulation of blood in the pleural space, can be caused by a number of conditions including blunt trauma, penetrating injury, thoracic surgery, and dissecting thoracic aneurysms. In the case of blunt trauma or penetrating injury pneumothorax may accompany hemothorax. The accumulation of blood in the pleural space exerts pressure on pulmonary structures. This causes the alveoli to collapse and decreases the surface area for gas exchange. Hypovolemia occurs as bleeding decreases the vascular volume. The severity of a hemothorax depends on the amount of blood loss. Massive hemothorax—blood loss greater than 1500 mL—can occur from trauma to the heart, great vessels, or intercostal arteries.
Assessment findings are dependent on the amount of blood loss. The client with a small hemothorax can be asymptomatic. Findings associated with a large hemothorax include
- Respiratory distress
- Diminished breath sounds
- Dull sound when the affected side is percussed
- Blood in the pleural space
Anterior and posterior chest tubes are inserted to remove blood. The physician may perform an open thoracotomy when the blood loss is excessive (from 1500 mL to 2000 mL) or persistent (200 mL per hour over a three hour period).
A key role of the nurse in caring for the client with a pneumothorax or hemothorax is assessing the chest drainage system and intervening appropriately if problems arise. Chest tubes are inserted for one of two reasons: to drain the chest cavity or to reinflate the lung. Chest drainage systems can be one-bottle, two-bottle, or three-bottle setups. Chest drainage systems using glass bottles have largely been replaced by lightweight disposable systems that use chambers rather than bottles as illustrated in Figure 5.4.
Figure 5.4 Chamber chest drainage system.
One-chamber set-ups do not allow for suction control and cannot handle large amounts of drainage. Two-chamber setups allow for suction and are capable of collecting large amounts of drainage. In the two-chamber setup, the first chamber collects the drainage, and the second chamber controls the amount of suction. In the traditional water seal or three-chamber setup, the first chamber collects the drainage, the second chamber acts as a water seal, and the third chamber controls the amount of suction. Refer to Figure 4.5 and the Points to Remember list that follows to help you review the management of a three-chamber water seal chest drainage system.
Figure 5.5 Three-Chamber chest drainage system.
The collection chamber acts as a reservoir for fluid that drains from the chest tube. A one-way valve in the water seal chamber prevents air from moving back into the chest when the client inhales. Tidaling, or an increase in water level, occurs with inspiration and returns to baseline with expiration. The suction control chamber regulates the amount of negative pressure applied to the chest cavity. The amount of suction applied is determined by the amount of water in the suction chamber. The amount of suction is generally set at 20 cm of water.
Points to remember for management of a three-chamber water seal chest drainage system include
- Monitor the color, amount, and consistency of the drainage.
- Note fluctuations in the water seal chamber. Fluctuations stop when the tubing is obstructed, when there is a dependent loop, or when the suction is not working properly.
- Assess the suction control chamber for bubbling. Constant bubbling in the water seal chamber can indicate an air leak. Assess the chest tube system for external air leaks. The physician should be notified at once if there is constant bubbling in the water seal chamber that is not related to an external air leak.
- Ensure that the drainage tube does not interfere with the client's movement. If the chest tube should become disconnected from the client, the nurse should cover the insertion site immediately with a petroleum gauze. (Petroleum gauze, sterile dressings, and tape should be kept at the client's bedside.) The client should be monitored for developing pneumothorax. The physician should be notified and equipment gathered in anticipation of reinsertion of the chest tube.
- When transporting the client, the chest drainage system should remain below chest level. If the tubing becomes disconnected from the collection device, cut off the contaminated tips of the tubing, insert a sterile connector, and reattach the tube to the chest drainage system. Do not clamp the chest tube during transport.
- When assisting with chest tube removal, instruct the client to perform a Valsalva maneuver. The tube is clamped and quickly removed by the physician. The nurse should simultaneously apply a small petroleum gauze covered by a 4"x4" gauze pad that is completely covered and sealed with nonporous tape. Following the removal of the chest tube the nurse should monitor the client for signs of recurring pneumothorax.