Asthma

75 Asthma




Overview/pathophysiology


Asthma is a chronic, reversible (in most cases) obstructive airway disease characterized by inflammation and mucosal edema, increased sensitivity of the airways, and airway obstruction (bronchospasm and in some children, excessive, thick mucus). Increased inflammation causes increased sensitivity of the airways and is the most common feature of asthma.


The prevalence of asthma and associated morbidity rates continue to rise in children. Asthma is the leading cause of chronic illness in children as well as a leading cause of hospitalization. An estimated 7 million have asthma, with an increased incidence in boys, children in poor families and/or in fair-poor health, and in African Americans (National Health Interview Survey, 2008) Asthma is the leading cause of school absences and accounts for an estimated loss of 12.8 million school days and is responsible for more hospitalizations, restricted activity, and significant health care costs than any other pediatric chronic illness (American Lung Association, 2006). The incidence of death due to asthma has decreased with about 3600 deaths in 2006 (CDC, FastStats–Asthma, 2009). The National Asthma Education and Prevention Program (NAEPP) published updated guidelines for diagnosis and management in 2007. The Expert Panel Report 3 (EPR-3) focuses on new guidelines for deciding treatment based on individual needs (looking at age and severity) and level of asthma control. It stresses that conditions change over time and regular monitoring is essential so that treatment can be adjusted as needed. Guidelines for children have been expanded to include 0-4 years, 5-11 years, and 12 years and older with stepwise approach for severity and control. Severity classification has been revised to include intermittent or persistent (mild, moderate, or severe). Each step includes patient/family education, environmental control, and management of comorbidities. Assessing asthma control and adjusting therapy depend on classification of control (well controlled, not well controlled, and very poorly controlled) (NAEPP EPR-3, 2007).



Health care setting


Primary care, with possible hospitalization resulting from severe acute attacks



Assessment


It is important to obtain a detailed history of current problems as well as past episodes.




Common early warning signs:


Breathing changes, sneezing, moodiness, headache, itchy/watery eyes, dark circles under eyes, easy fatigue, sore throat, trouble sleeping, chest or throat itchiness, downward trend in peak flow values, cough especially at night (hallmark symptom of asthma), slight tightness in chest.



Symptoms of acute episode:


Coughing, shortness of breath, dyspnea, anxiety, apprehension, tightness in chest, and wheezing (primarily on expiration).



Severe asthma symptoms:


Severe coughing, shortness of breath, tightness in chest and/or wheezing, and difficulty talking, eating, or concentrating. The mucosal edema causes shortness of breath, tachypnea or bradypnea, hunched shoulders (posturing), suprasternal and intercostal retractions, cyanosis, increasing dyspnea, nasal flaring and use of accessory muscles, extreme anxiety, and apprehension.



Symptoms of severe respiratory distress and impending respiratory failure:


Profuse diaphoresis, sitting upright and refusing to lie down, suddenly becoming agitated or becoming quiet when previously agitated, decrease in or absence of wheezing.



Physical assessment:


Chest has hyperresonance on percussion. Breath sounds are loud and coarse, with sonorous crackles throughout the lung fields. Prolonged expiration is noted. Coarse rhonchi may be heard, as well as generalized inspiratory and expiratory wheezing that becomes more high pitched as obstruction increases. With minimal obstruction, wheezing may be minimal or heard only on end expiration with auscultation. Breath sounds and crackles may become inaudible with severe obstruction or bronchospasm. Posturing occurs to facilitate breathing. Pulsus paradoxus (an abnormally large decrease in systolic blood pressure and pulse wave amplitude during inspiration) also may be noted because of lung hyperinflation.


Children with chronic asthma may develop a barrel chest with depressed diaphragm, elevated shoulders, and increased use of accessory muscles of respiration.


Caution: If symptoms are untreated or treated unsuccessfully, an acute asthma attack may progress to status asthmaticus, a severe unrelenting attack. Status asthmaticus is an acute, severe, and prolonged asthma attack in which respiratory distress continues despite vigorous therapeutic measures and may result in death.



Diagnostic tests




Arterial blood gas (ABG) values:


Reveal status of oxygenation and acid-base balance. In severe asthma exacerbation with Pao2 less than 60 mm Hg (on room air) and Paco2 42 mm Hg or greater, child may have cyanosis and may progress to respiratory failure. ABG values are not obtained often in children except in intensive care unit and with initial assessment in order to provide atraumatic care. If possible, topical anesthetics are used to decrease pain and anxiety with blood draws.



Pulse oximetry:


Noninvasive method that reveals decreased O2 saturation (usually less than 93%-95%, depending on protocol of facility) and helps provide atraumatic care.



Pulmonary function tests (spirometry):


Provide an objective method of evaluating presence and degree of lung disease, as well as response to treatment, and usually can be performed reliably on children by 5 or 6 yr of age. These tests typically show diminished maximal breathing capacity, tidal volume, and timed vital capacity.



Chest x-ray examination:


To rule out pneumonia and assess for air trapping. It is also used to evaluate possible cardiomegaly secondary to pulmonary hypertension resulting from chronic obstruction. Typical findings in a child with significant asthma symptoms are hyperinflation, atelectasis, and flattened diaphragm.



Complete blood count:


May show slight elevation during acute asthma, but white blood cell elevations greater than 12,000/mm3 or an increased percentage of band cells may indicate a respiratory infection. Eosinophils greater than 500/mm3 tend to suggest an allergic or inflammatory disorder.



Peak expiratory flow rate:


Assesses severity of asthma by measuring maximum flow of air that can be forcefully exhaled in 1 sec using peak flow meter (PFM). Each child’s peak expiratory flow rate (PEFR) varies according to age, height, sex, and race. Once personal best value is established, it is recommended that it be done 1-2 times/day in children with moderate-to-severe persistent asthma. The child should measure the PEFR three times with at least 30 sec between each measurement; then record the highest reading. Maintaining a diary or log book is beneficial and helps direct plan of care. While this test is used for monitoring control, it is not used for the initial diagnosis.



Sputum:


Gross examination may reveal increased viscosity or actual mucus plugs. Culture and sensitivity may reveal microorganisms if infection was the precipitating event. Cytologic examination will reveal elevated eosinophils, which is commonly associated with asthma. It is rarely done in children.



Serum theophylline level:


Important baseline indicator for patients who are receiving this therapy, although it is now considered a third-line agent and used infrequently. Current guidelines call for a serum concentration of 5-15 mcg/mL. Theophylline toxicity can occur with serum levels greater than 20 mcg/mL. Side effects include nausea, vomiting, headache, irritability, and insomnia. Early signs of toxicity are nausea, tachycardia, irritability, and seizures. Dysrhythmias occur at serum levels greater than 30 mcg/mL.



Skin testing:


The 2007 revised guidelines issued by the NAEPP EPR-3 recommend consideration of subcutaneous allergen immunotherapy for patients with allergic asthma.





Nursing diagnosis:


Ineffective airway clearance

related to bronchospasm, mucosal edema, and increased mucus production


Desired Outcomes: Child with a significant asthma attack: Within 48 hr of interventions/treatment, adventitious breath sounds, cough, and increased work of breathing (WOB) are decreased. Within 72 hr, respiratory rate (RR) returns to child’s normal range, and retractions and nasal flaring disappear. Child with a mild asthma attack: Within 3 hr after interventions/treatment, adventitious breath sounds and cough are decreased, and retractions and nasal flaring are absent.




Note:


WOB means ease or effort of breathing. Signs of increased WOB include nasal flaring, retractions, and use of accessory muscles.





















































ASSESSMENT/INTERVENTIONS RATIONALES
Assess respiratory status with initial assessment, with each vital sign check, and prn. After establishing the baseline, changes can be detected quickly with subsequent assessments, enabling rapid intervention.
Assess RR, heart rate (HR), O2 saturation, and breath sounds before and several minutes after each nebulizer treatment or metered-dose inhaler (MDI) administration. These assessments help determine child’s status and effectiveness of medication in decreasing bronchospasm or mucosal edema and enabling more effective airway clearance.
Administer nebulizer treatment or MDI, usually albuterol, as prescribed. These therapies decrease bronchospasm or mucosal edema, thereby opening the airway and enabling more effective airway clearance.
Use a spacer or holding chamber when administering MDI. This is the most effective method of getting maximum amount of medication delivered to a child. A mask may be required with a spacer in children less than 5 yr of age or anyone who is unable to seal lips effectively around the mouthpiece.
Hold albuterol treatment if HR is:
– Greater than 180 bpm (children 2 to 3 yr)

– Greater than 160 bpm (children 3 to 6 yr)

– Greater than 140 bpm (children 6 to 12 yr)

– Greater than 120 bpm (children older than 12 yr)

Notify health care provider as directed.		 Tachycardia is a major side effect of albuterol. When it is present, the health care provider needs to assess the patient to ensure that side effects of medication do not outweigh the benefit of decreasing bronchospasm.
Position child in high Fowler’s position and encourage deep breathing. This will ensure the child has maximum lung expansion and that medication will be dispersed more effectively, thereby improving airway clearance.
Check PEFR in children 5 yr of age and older before and after each albuterol treatment using PFM. These assessments monitor effectiveness of medication in decreasing bronchospasm and increasing effective airway clearance. For more information about PEFR, see Diagnostic Tests section.
Encourage deep breathing and effective cough q2h while awake. This loosens and expectorates secretions (many young children cough up secretions and swallow them) and will lead to more effective airway clearance.
Teach children 7 yr old and older breathing exercises and controlled breathing. Children younger than 7 are diaphragmatic breathers normally. Proper diaphragmatic breathing decreases WOB and improves chest wall mobility and airway clearance.
Administer other medications (inhaled, intravenous [IV], or by mouth [PO]) as prescribed (usually corticosteroids). Corticosteroids decrease inflammation, thereby improving airway clearance. Antibiotics are only given if a bacterial infection is present.
Assess and document intake and output (I&O) q4h. Ensure that a minimum urine output (UO) of 1 mL/kg/hr is met. Assessing I&O on a regular basis alerts one to inadequate intake or output before the child shows signs of dehydration. Dehydration thickens secretions and decreases airway clearance.
Assess hydration status q4h, including level of consciousness (LOC), anterior fontanel (if child is younger than 2 yr old), abdominal skin turgor, and urine output. Because of increased insensible water loss (owing to increased RR, metabolic rate, and secretions), child may still become dehydrated even if receiving maintenance fluids and having appropriate I&O. Ongoing assessments detect early changes and provide more prompt resolution of the problem. Dehydration thickens secretions and decreases airway clearance. Signs of dehydration include decreasing LOC, sunken fontanel, tented abdominal skin, and decreasing urine output.
Encourage maintenance fluids, preferably orally, that are appropriate for child’s weight. Fluids thin mucus and improve ability to expectorate it, which improves airway clearance. Some children may need IV fluids because of increased WOB.
Give child/family specific guidelines for hydration (maintenance fluids). For example, a 2-yr-old child who needs 1200 mL/day and drinks from a 4-oz “sippy” cup, needs to drink 10 “sippy” cupfuls/day. Understanding appropriate care improves adherence to the treatment regimen and decreases symptoms.
Avoid iced fluids and limit caffeinated fluids. Iced fluids may trigger bronchospasm. Excessive intake of caffeinated fluids may increase risk of cardiovascular and central nervous system side effects of many medications.
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Jul 18, 2016 | Posted by in NURSING | Comments Off on Asthma

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