I nfection Prevention

Risky business: Aspiration pneumonia

ANY TIME A patient inhales foreign matter such as food or bacteria into his lower airway, he’s at risk for aspiration pneumonia. Patients who develop aspiration pneumonia are commonly older or debilitated; receiv- ing nasogastric tube feedings; and have an impaired gag reflex, poor oral hygiene, or a decreased level of consciousness. Preventing aspiration pneumonia and recognizing the are key nursing measures to protect your patients.

How pneumonia develops The most common form of aspiration pneumonia is bacterial infection from inhalation of bacteria that normally reside in the upper airways. The aspirated material impairs lung defenses, causes inflammation, and leads to bacterial growth and a resulting pneumo- nia. If untreated, the pneumonia can cause death. Most lung tissue for these reasons: commonly, the bacteriologic findings in this type of • Because of their acidic nature, the aspirated gastric pneumonia include Gram-positive cocci, Gram-negative contents cause a chemical burn of the tracheobronchial rods, and occasionally anaerobic bacteria. tree and pulmonary parenchyma. If a patient aspirates gastric contents, the volume and • An inflammatory response occurs, resulting in destruc- character of the aspirated material are primarily responsi- tion of alveolar-capillary endothelial cells. ble for the complications of aspiration pneumonia. For • Protein-rich fluids leak from the endothelial cells into example, a small localized aspiration from regurgitation the interstitial and intra-alveolar spaces. can cause pneumonia and acute respiratory distress; a • Surfactant (a lipoprotein substance secreted in the massive aspiration is usually fatal. lungs that helps keep lung tissue elastic) is lost, causing A full stomach contains solid food particles. If these are the airways to close and the alveoli to collapse. aspirated, the airways become blocked and secondary • The impaired exchange of oxygen and carbon dioxide infection sets in. Even if the patient is fasting, his stomach causes respiratory failure. contains acidic gastric juice which, if aspirated, can be very destructive to the alveoli and capillaries. What to look for Fecal contamination of gastric contents (more likely The signs and symptoms of aspiration pneumonia vary. with intestinal obstruction) increases the likelihood of The predominant symptoms may be headache, low- death for these reasons: grade fever, pleuritic pain, myalgia, rash, and pharyngi- • Intestinal organisms produce endotoxins that may be tis. After a few days, the patient expectorates mucoid absorbed into the patient’s system. or mucopurulent . In severe pneumonia, the • Thick, protein-rich material found in the intestinal patient’s cheeks are flushed and central affects contents may obstruct the patient’s airway, leading to the lips and nail beds, a late sign of poor oxygenation atelectasis and secondary bacterial invasion. (). Aspiration pneumonia may develop from aspiration of The patient may have when reclin- substances with a pH of less than 2.5 and a volume of gas- ing (); he may prefer being propped up or sit- tric aspirate greater than 0.3 mL per kilogram of body ting in bed leaning forward (orthopneic position) in an weight (about 20 to 25 mL in adults). The more acidic effort to achieve adequate gas exchange without coughing and the larger the volume, the more it will damage the or deeply. His appetite may be poor, and he

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may sweat excessively and tire easily. Sputum is often Risk factors for aspiration purulent; however, this isn’t a reliable indicator of the • seizure activity cause of the pneumonia. • decreased level of consciousness from trauma, drug or alco- The patient’s underlying condition may affect his signs hol intoxication, excessive sedation, or general anesthesia and symptoms. For example, cancer and therapy with • nausea and vomiting in a patient with a decreased level of immunosuppressants decrease resistance to infection, so a consciousness patient with either condition may have fever, , and • stroke physical findings that indicate consolidation of lung tissue: • swallowing disorders • increased tactile (vocal vibration detected on • cardiac arrest palpation) • silent aspiration (aspiration without outward signs of • dullness coughing or respiratory difficulty) • bronchial breath sounds • (when auscultated, the spoken “E” becomes ability of newer antibiotic agents must also be consid- a loud, nasal-sounding “A”) ered. See Antibiotic therapy for more information. • whispered (whispered sounds easily aus- Several organizations have published guidelines and cultated though the chest wall). comprehensive reviews of the medical management of These changes occur because sound is transmitted bet- aspiration pneumonia. Guidelines may be classified in ter through solid or dense tissue (consolidation) than terms of risk factors (see Risk factors for aspiration), treat- through normal air-filled tissue. ment setting (inpatient versus outpatient), or specific In a patient with chronic obstructive pulmonary dis- pathogens. ease, purulent sputum or slight changes in respiratory Usually, therapy with parenteral agents is changed to symptoms may be the only sign of pneumonia. oral antimicrobial agents when the patient shows evi- Determining whether increased symptoms signal an dence of a clinical response and he’s stable and able to exacerbation of the underlying disease or an additional tolerate oral medications. Patients with pneumonia infection may be difficult. caused by bacterial pathogens are treated for 1 to 2 weeks after their fever subsides. Those with atypical pneumonia What the tests tell you (such as Legionella or Mycoplasma pneumoniae) are usually The diagnosis of pneumonia is made by history, physi- treated for 10 to 21 days. cal examination, chest X-ray, and sputum examination. If a patient with aspiration pneumonia develops hypox- Obtain a sputum sample, if possible, by having the pa- emia, he requires oxygen therapy. Pulse oximetry or tient do the following: analysis of arterial blood gases helps determine his oxy- • rinse his mouth with water to minimize contamination gen needs and evaluate the effectiveness of oxygen thera- by normal oral flora py. Arterial blood gases may be used to get a baseline • breathe deeply several times measure of his oxygenation and acid-base status; pulse • deeply oximetry is used for continuous monitoring of his oxygen • expectorate the raised sputum into a sterile container. saturation and response to therapy. If oxygen therapy Sputum may also be obtained by more invasive proce- alone can’t maintain an adequate oxygen saturation level, dures such as nasotracheal or orotracheal suctioning with a he needs more aggressive respiratory support via endotra- sputum trap or by fiberoptic bronchoscopy. Bronchoscopy cheal intubation or mechanical ventilation. is often used in patients with acute severe infection, in patients with chronic or refractory infection, in immuno- Possible complications compromised patients when a diagnosis can’t be made Severe complications of aspiration pneumonia include: from an expectorated or induced specimen, and in mech- • hypotension, shock, and respiratory failure (especially with anically ventilated patients. Gram-negative bacterial disease in older patients) • atelectasis (from accumulated secretions obstructing a How it’s treated bronchus or small airways), which may occur at any The treatment of aspiration pneumonia includes anti- stage of acute pneumonia biotics as determined by results of a Gram stain and • parapneumonic pleural effusions (any pleural effusion as- culture and sensitivity test. Guidelines exist to guide sociated with bacterial pneumonia, lung abscess, or antibiotic choice, but resistance patterns, prevalence of bronchiectasis), which occur in at least 40% of bacterial etiologic agents, patient risk factors, and costs and avail- pneumonias

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• superinfection (the development of an additional infec- coughing, frequent position changes, and early ambula- tion brought on by the use of antibiotics for an infection tion. To reduce or prevent serious complications of somewhere else in the body), which may occur with the pneumonia, older adults should receive vaccination administration of very large doses of antibiotics such as against pneumococcal and influenza infections. penicillin, or with combinations of antibiotics. Preventing aspiration Gerontologic considerations Prevention is a primary goal when you care for patients Pneumonia in older people results in a higher mortality at risk for aspiration. Risk factors include: rate. However, the diagnosis may be missed because the • decreased level of consciousness classic symptoms of cough, , sputum produc- • supine positioning tion, and fever may be absent or masked in older adults. • presence of a nasogastric tube Instead, general deterioration, weakness, abdominal • tracheal intubation and mechanical ventilation symptoms, anorexia, confusion, tachycardia, and tachyp- • bolus or intermittent feeding delivery methods nea may signal the onset of pneumonia. • advanced age. The presence of some signs of pneumonia in older You can take several preventive measures to protect at- adults may be misleading. Abnormal breath sounds, for risk patients from aspiration pneumonia. example, may be caused by microatelectasis that occurs as Keep the patient in a semirecumbent position. a result of decreased mobility, decreased lung volume, or Elevating the head of his bed to between 30 and 40 other respiratory function changes that go with aging. degrees decreases the risk of aspiration. The patient may require a chest X-ray to differentiate Compensate for absent reflexes. A patient who can’t pneumonia from chronic heart failure, which is often adequately coordinate protective glottic, laryngeal, and seen in older adults, as the cause of signs and symptoms. cough reflexes has a greater risk of aspiration. This haz- Supportive treatment for pneumonia includes hydra- ard is increased if the patient: tion (with caution and frequent assessment because fluid • has a distended abdomen overload poses a greater risk in older adults), supplemen- • is supine tal oxygen therapy, and assistance with deep breathing, • has his upper extremities immobilized by intravenous infusions Antibiotic therapy • has received a local anesthetic to the oropharyngeal or In patients who are mildly to moderately ill and have a low risk of laryngeal area for diagnostic procedures Pseudomonas infection, the following antibiotics may be used: • has been sedated • second-generation cephalosporins (cefuroxine [Ceftin, • has had long-term intubation. Zinacef], cefamandole [Mandol]) During vomiting, most people can protect their airway • nonpseudomonal third-generation cephalosporins (ceftriax- by sitting up or turning on the side and coordinating one [Rocephin], cefotaxime [Claforan], ampicillin-sulbactam breathing, coughing, gag, and glottic reflexes. A patient [Unasyn]) • fluoroquinolones (ciprofloxacin [Cipro], levofloxacin with these reflexes intact shouldn’t have an oral airway [Levaquin]) inserted to protect him from aspirating his own vomitus. • carbapenem (meropenem [Merrem]). If a patient has an artificial airway in place, it should be For combination therapy, any of these may be used with an pulled out the moment he gags so as not to stimulate the aminoglycoside. pharyngeal gag reflex and promote vomiting and aspira- For patients at high risk for Pseudomonas infection, an tion. Suctioning oral secretions with a catheter should be antipseudomonal penicillin plus an aminoglycoside (amikacin performed with minimal pharyngeal stimulation. [Amikin], gentamicin) or a beta-lactamase inhibitor Assess feeding tube placement. Tube feedings must be (ampicillin/sulbactam [Unasyn], ticarcillin/clavulanate given only when the feeding tube’s correct position is [Timentin]) may be used. Other combination therapies may certain. Feedings are given slowly and regulated by a also be used, depending on patient characteristics. feeding pump. Many patients receive enteral feeding For older patients with multiple comorbidities, a fluoro- quinolone may be preferred. Fluoroquinolones are sometimes directly into the duodenum through a small-bore flexible reserved for use in higher-risk or drug-intolerant patients to feeding tube or surgically implanted tube. A patient who’s slow the emergence of resistance to this class of antibiotics. intubated may aspirate foreign material even with a naso- These are guidelines only; treatment regimens may be modi- gastric tube in place, so assessment of tube placement is fied for individual patients. key to preventing aspiration. The best way to determine tube placement is with an X-ray.

10 LPN2008 l Volume 4, Number 4 Other than X-ray, the most reliable method to assess to let the stomach partially empty. tube placement is by observation of the aspirate and testing Manage the effects of prolonged intubation. Prolonged its pH. Gastric fluid may be grassy green, brown, clear, or endotracheal intubation or tracheostomy can depress the colorless. Mucus aspirated from the lung may be off-white laryngeal and glottic reflexes because of disuse. En- or tan. Pleural fluid is watery and usually straw-colored. courage patients with prolonged tracheostomies to Gastric pH is typically lower (more acidic) than the pH phonate (make vocal sounds) and exercise their laryngeal of intestinal or respiratory secretions. Gastric pH is usu- muscles. For patients who’ve had long-term intubation or ally between 1 and 5; intestinal or respiratory pH is 7 or tracheostomies, having a rehabilitation therapist experi- higher. enced in speech and swallowing disorders (such as a Although observation of aspirated contents and pH speech therapist) work with the patient to assess the swal- evaluation should be performed for intermittent feedings lowing reflex may be helpful. with small-bore tubes, the pH method isn’t useful for Protect patients at risk for aspiration pneumonia by continuous feedings because you’d be checking the using preventive measures and by responding quickly infused formula rather than the patient’s gastric fluid. when you detect signs and symptoms of this dangerous Properly administer tube feedings. Patients receiving respiratory disorder. LPN continuous infusions should receive small volumes under low pressure and be placed in an upright position to help prevent aspiration. Patients receiving infusions at timed Selected references intervals are maintained in an upright or semirecumbent Critical Care Nursing Made Incredibly Easy!, 2nd edition. Philadelphia, Pa., Lip- pincott Williams & Wilkins, 2007. position (head of the bed elevated to 30 to 40 degrees) Smeltzer SC, et al. Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, during the feeding and for at least 30 minutes afterward 11th edition. Philadelphia, Pa., Lippincott Williams & Wilkins, 2007.

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