It is well known that respiratory failure is the most common cause of cardiopulmonary arrest in children, which is why both Basic Life Support (BLS) and Pediatric Advanced Life Support (PALS) algorithms begin with an evaluation of the airway and breathing. Compared with adults, children have some unique anatomical airway considerations. The upper airway in small children is more prone to obstruction secondary to their having large heads with prominent occiputs, causing the head and chin to tilt towards the chest when lying supine. The narrowest portion of the pediatric airway is at the level of the cricoid ring in the subglottic space, which may become a point of obstruction when soft tissue becomes inflamed.
Subjective observation of a child can be influential in deciding whether airway compromise may be present. Visualizing the child's level of alertness and ability to interact with others helps to gauge the level of illness. Appearance of the child's work of breathing is important in assessing respiratory distress. Work of breathing is assessed by determining whether the child is tachypneic, using accessory muscles, or has nasal flaring. Each of these visual cues allows providers to determine the level of respiratory distress in a patient.
Normal values for respiratory rates are age-dependent and vary widely from the neonate to the adolescent. Children should have an appearance of unlabored, quiet breathing. Visible suprasternal or intercostal retractions, with or without nasal flaring, are signs of increased work to move air into the lungs. In infants and toddlers, increased work of breathing may be seen as an inward motion of the anterior chest on inspiration due to the higher compliance of the chest wall. A late visual finding of respiratory distress may be cyanosis, which is more indicative of impending respiratory failure.
Auditory cues also are important in determining the presence and severity of respiratory distress. Inspiratory stridor, typically loud and high pitched, indicates the presence of large airway obstruction above the thoracic inlet. Causes of inspiratory stridor include edema of the subglottic space, a foreign body in the glottis or sublglottic space, edema of supraglottic structures, laryngeal trauma, or retropharyngeal abscess. New onset stridor in children beyond infancy indicates some level of airway compromise requiring close monitoring and possibly immediate intervention. Auscultation of the chest in healthy children should demonstrate clear vesicular breath sounds both on inspiration and exhalation. The presence of an expiratory wheeze is a sign of some level of intrathoracic airway obstruction. A loud monophonic wheeze is usually a sign of large airway obstruction, while a polyphonic wheeze indicates obstruction of multiple small airways of different calibers contributing to the multiple pitches heard. Rales (commonly called crackles) heard on inspiration are caused by the opening of previously closed alveoli and typically are associated with pneumonia or atelectasis.
Other useful tools in evaluating respiratory compromise are pulse oximetry and measuring pulsus paradoxus. The presence of hypoxemia in a previously healthy child is nearly always related to decreased gas exchange at the level of the alveoli, which may be a direct result of decreased overall air movement (minute ventilation) or a ventilation to perfusion mismatch due to water, blood, or purulent material at the liquid/gas interface leading to deoxygenated blood returning to the systemic supply. Pulsus paradoxus is the fluctuation of arterial systolic blood pressure while breathing. It is measured by taking the systolic blood pressure during inspiration and subtracting it from the systolic pressure during exhalation During significant airflow obstruction leading to a pulsus paradoxus of 20 mmHg or more, the difference can often be physically palpable. The single most important aspect of clinically assessing a child in respiratory distress is constant surveillance. Whenever any intervention is applied to a child, it is important to assess for clinical response in order to guide continued therapy.
Suggested Equipment for Office Respiratory Emergencies in Children
OFFICE PREPAREDNESS FOR PULMONARY EMERGENCIES
Preparation for common respiratory emergencies in children requires appropriate training for clinic personnel in addition to the right equipment and medications to stabilize patients from the newborn period through adolescence. At a minimum, all clinical personnel in the pediatric setting should have basic life support training. Pediatricians should ensure they are current in pediatric-specific resuscitation skills by staying current in the PALS course, sponsored by the American Academy of Pediatrics and the American Heart Association.1 Reinforcement of evaluation and procedural skills in the office setting can be aided by running mock codes on a periodic basis. These drills should be followed by a group discussion among all participants and observers to help identify problems with methodology and equipment Any issues identified then should be corrected.
Suggested Medications for Office Respiratory Emergencies in Children
Office Equipment for Pulmonary Emergencies
Necessary equipment and supplies can be grouped into requirements for maintaining a patent airway to those necessary for improving breathing and gas exchange. Important considerations in equipment selection include the comfort of the provider in using the equipment, and the level of clinical support available. For example, if a pediatric office is co-located with an emergency department or inpatient facility, it may be less important to have invasive airway management tools (laryngoscopes and endotracheal tubes) immediately on hand than it would be for an office in a remote setting.
Table 1 (see page 886) lists suggested equipment for managing pediatric respiratory distress. Airway maintenance equipment includes oral airway appliances, nasal trumpets, laryngeal mask airways, a working laryngoscope with multiple sized blades, endotracheal tubes spanning the entire pediatric age range, and suction. Appropriate sized inflatable masks that can create a good seal around the nose and mouth are perhaps the most important piece of equipment available for those providers who are not comfortable with intubation.
Once an airway is obtained, or if the patient is able to self-maintain an airway, equipment for breathing may be required. If wall oxygen is not available, a full oxygen tank with a working regulator is necessary. A self-inflating bagvalve-mask setup can be used to deliver breaths manually either with room air or connected to oxygen. It is important to recognize that bag-valve-mask setups are not capable of delivering oxygen passively (blow-by) via the mask due to a valve that requires the bag to be squeezed to allow gas flow to the patient. For this reason, many providers prefer to use an anesthesia bag with a manometer connected to an oxygen source. This setup allows the provider to ventilate a patient actively while monitoring airway pressure or to deliver oxygen flow passively through a mask. Most children do not present to a pediatric office in acute respiratory failure, but in distress, so they need a higher fraction of inspired oxygen in addition to medications.
Whatever mode of oxygen delivery is used, it should be sufficient to maintain normoxemia and to allow the patient to breathe comfortably to remove carbon dioxide. Nasal cannula is appropriate when lower flows of O2 are sufficient. When more than 2 or 3 1pm of O2 is required, or simultaneous delivery of aerosolized medication is desired, a comfortably fitting oxygen mask is necessary.
It is important to recognize that the mask needs to have holes or one-way valves in place to allow the patient to blow off carbon dioxide. The common mistake of taping over holes or valves in the mask to maximize oxygen or medication delivery should be avoided.
If delivery of a high fraction of inspired oxygen is necessary, a nonrebreather mask with an oxygen reservoir can deliver nearly 100% FIO2 (fraction of inspired oxygen). Finally, for delivery of aerosolized medications to the airways, nebulizer cups and mouthpiece or facemask can be attached to either wall oxygen at 8 1pm or to an air compressor.
Pediatric Asthma Severity Score
Common medications for children in respiratory distress include systemic and aerosolized medications (Table 2, see page 887). Common systemic medications include various corticosteroids, including prednisone, prednisolone, methylprednisolone, and decadron. Subcutaneous terbutaline may also be used in status asthmaticus. Aerosolized medications are typically delivered either through nebulization or a metered dose inhaler (MDI). Commonly used aerosolized medications for children in distress include albuterol, ipratropium bromide, racemic epinephrine, and budesonide.
A recent consensus statement released by the American College of Chest Physicians stated that, regardless of the clinical setting or age of the patient, MDIs and nebulized aerosols provide similar outcomes when correct techniques are used.2 For pediatric patients seen in an acute care setting, a total of 8 randomized controlled trials were evaluated in a meta-analysis. There were no significant differences in pulmonary function measures or symptom scores between the use of nebulized albuterol or albuterol delivered by MDI with a valved holding chamber.2
Under ideal settings, an MDI with a valved holding chamber can deliver up to 30% of the intended dose. New compressors with a clean nebulizer cup can deliver up to 10% of the desired dose. Regardless of the method of drug delivery chosen, the technique used to deliver the medication is of utmost importance. A valved holding chamber connected to an MDI canister allows for decreased pharyngeal deposition of the medication compared to using an MDI alone. Coordination between actuation of the MDI canister and inspiration of the patient is essential. Children experiencing dyspnea may be too anxious to replicate good MDI technique multiple times.
When using wall oxygen to drive nebulizer delivery, a flow of 8 1pm will allow for the greatest fraction of respintole particle size available for delivery to the lower airways.3 When available, using wall oxygen to drive nebulized medications has several advantages over using a compressor. In addition to supplying a higher fraction of inspired O2 available for gas exchange, oxygen is also a bronchodilator. Using wall oxygen also removes the variability in flow rate that is invariably seen in compressors over time.
Children who are incapable of complying with the use of a mouthpiece should be given an appropriate sized tight-fitting mask with exhalation valves to avoid rebreathing CO2. In school-age and older children, patient preference as to mask or mouthpiece should be the guiding factor in device selection, as neither technique has proven to have a significant clinical benefit over the other.4 Great care should be taken in avoiding delivery of "blow-by" medication, as the amount of drug delivered to the lungs greatly decreases the further the mouthpiece or mask is moved away from the face.5
COMMON PULMONARY EMERGENCIES SEEN IN THE PEDIATRIC OFFICE SETTING
Although there are many clinical situations that lead to respiratory distress in children, including asthma, viral bronchiolitis, laryngotracheobronchitis, pneumonia, spontaneous pneumothorax, foreign body aspiration, blunt or penetrating trauma, hydrocarbon aspiration, and near drowning, this article concentrates on current trends in treating the most common respiratory emergencies.
As a highly prevalent chronic disease in children and one of the most common causes of pediatric hospitalization, asthma exacerbations are also the most frequent source of respiratory distress in children seen in the pediatric clinic. Asthma exacerbations are characterized by smooth muscle spasm, mucosal edema, and mucous plugging. The combination of these events leads to airflow obstruction with air trapping in the lungs and a mismatch in ventilation-perfusion relationships. A practical definition of status asthmaticus is respiratory distress in an asthmatic patient who is not responding to initial doses of bronchodilators.6
Children typically present to the pediatric office with wheezing and coughing along with signs of anxiety secondary to their increased work of breathing. Less commonly, children may present in respiratory failure. Multiple schemes for scoring the severity of pediatric asthma exacerbations exist, each with similar clinical features evaluated. Gorelick et al. recently published the results of the performance of a pediatric asthma severity score (PASS) used prospectively in the emergency department setting (Table 3, see page 888). The score showed a high level of prediction on need for hospitalization, responsiveness, and interrater reliability using three clinical parameters: wheezing, prolonged expiration, and work of breathing.7
In treating a child in status asthmaticus, continuous monitoring of cardiorespiratory status, using a heart monitor, pulse oximetry, and repeated physical assessments is essential in guiding therapy.
β-agonists, β-agonists are the mainstay in bronchodilation therapy for asthma. Commonly used β-agonists include albuterol, levalbuterol, terbutaline, and epmephrine. Levalbuterol, the pure Risomer of albuterol, has gained recent popularity as an aerosolized medication available in the US in nebulizable form. A recent large randomized trial comparing the use of albuterol with levalbuterol for children with acute asthma exacerbations demonstrated a significant protective effect against hospitalization in the levalbuterol group. For those children hospitalized, children treated with levalbuterol did not experience a shorter length of stay.8 Currently, there is controversy as to whether the benefits provided by levalbuterol justify the increased cost as compared to albuterol. Although older asthma protocols in the literature call for the use of subcutaneous epmephrine, a few prospective randomized trials in children have not shown its use to be beneficial when compared to nebulized albuterol or subcutaneous terbutaline.9,10 Subcutaneous terbutaline, with more selective β2-agonist properties than epinephrine, has demonstrated utility in children during asthma exacerbations.10,11 In one randomized trial, Simons et al.12 found efficacy at doses as low as 3 mcg/kg, with the best clinical response at a dose of 12 mcg/kg.
The most commonly administered bronchodilator is albuterol, either nebulized or in MDI form. Typical doses range from 0.05 to 0. 15 mg/kg, although there is no clear consensus as to a single appropriate dose. For children with a weak response to a single dose of albuterol, or in significant distress, continuous nebulized albuterol driven by wall oxygen may be the most appropriate method of delivery. This may be due to the highly variable amount of medication delivered to the lower airways in anxious children who may not fully cooperate with a tightly fitting mask.13-15 Doses of continuous albuterol most frequently cited range from 4 to 10 mg per hour, although some practitioners will use much higher doses.
Corticosteroids. The National Asthma Education and Prevention Program recommends the use of systemic corticosteroids for asthma exacerbations that do not completely respond to inhaled β-agonists.16 Becker et al. have demonstrated that oral corticosteroids are as effective as parenteral steroids during asthma exacerbations in children.17 Systemic corticosteroids, given early in the course of an asthma exacerbation, can decrease the chances of hospitalization, or once hospitalized, decrease the length of stay.18 The benefits of systemic corticosteroids in improving pulmonary function may be measured after 6 hours of administration.19 Current recommendations for oral corticosteroids are 1 to 2 mg/kg per day (maximum of 60 mg per day) in two divided doses.20 There is no strong consensus as to length of systemic corticosteroid treatment, although published reports show a benefit anywhere from a single dose to 7 days of therapy. Administration of oral corticosteroids is more convenient and less expensive than parenteral administration. When a child does not tolerate oral corticosteroids, parenteral administration is necessary. For intravenous memylprednisolone, the recommended dosing schedule is also 1 to 2 mg/kg per day in two divided doses.16,21
Anticholinergic therapy. Ipratropium bromide is the most frequently used inhaled anticholinergic agent in acute asthma. Several randomized controlled trials and a meta-analysis have found that repeated doses of nebulized ipratropium every 20 to 60 minutes helps to decrease the rate of hospitalization in children with severe asthma exacerbations.22-24 Similar clinical benefits have been reported at doses of 250 meg or 500 meg. There is no strong consensus on length of treatment, although a similar study evaluating the use of ipratropium for inpatient pediatric asthma in addition to albuterol and systemic steroids has not shown any additional measured benefits.25
Respiratory syncytial virus (RSV) and the parainfluenza viruses remain the leading causes of hospitalization for respiratory illnesses in infants and young children. Human metapneumovirus has recently been implicated as a significant cause of bronchiolitis in infants and small children. RSV bronchiolitis is characterized by sloughing of small airway epithelium in conjunction with airway edema. The clinical features typically include tachypnea and retractions with expiratory wheezing, usually accompanied with profuse nasal secretions. Traditional treatment involves close monitoring of clinical status, suctioning of nasal and oral secretions, and supplemental oxygen therapy when indicated. Medications frequently used to treat bronchiolitis include aerosolized albuterol, racemic epinephrine, and systemic corticosteroids.
A recent systematic review of the literature examining the use of systemic corticosteroids in infants with RSV bronchiolitis evaluated 15 randomized controlled clinical trials.26 This review did not find any benefits of using corticosteroids as compared to placebo for length of hospital stay or improvement in clinical scores. King et al.27 recently reported the results of a systematic review that evaluated eight randomized trials for epinephrine, 13 trials for albuterol, and 13 trials for systemic corticosteroids. The conclusion of this analysis is that there is insufficient evidence to recommend the routine use of any of the studied medications for infants with viral bronchiolitis. A systematic review of 14 randomized trials evaluating the use of aerosolized epinephrine as compared to albuterol or placebo in infants with viral bronchiolitis found evidence of some clinical benefit with epinephrine in the outpatient setting, but not in the inpatient setting.28
As the pathophysiology of small airway disease in viral bronchiolitis differs from asthma, traditional medications used for status asthmaticus have not shown much clinical utility in large groups of infants with RSV bronchiolitis. Perhaps the most significant supportive therapy for infants with RSV bronchiolitis is nasal suctioning. The nasopharynx provides 50% of all airway resistance in healthy individuals. Any obstruction by edema or secretions significantly increases resistance to flow and work of breathing. In addition to close monitoring and supportive care, infection control measures for contact with droplets oentaining the virus should be observed. Providers need to reassess response to interventions continually and be able to provide escalating respiratory support. Pulse oximetry serves as an excellent indicator of respiratory distress, with a saturation of less than 92% generally leading to hospitalization.29 Tachypnea may worsen to the point of interfering with swallowing and increasing the risk of aspiration.
Children with viral croup initially suffer from traditional cold symptoms, typically followed by a barky cough, hoarse voice, and stridor during the following 24 to 48 hours. The barky cough and stridor are attributed to subglottic edema. Croup is one of the most common causes of stridor in the primary care setting. Although many infectious agents can cause croup, the most common are parainfluenza virus 1 and 3, followed by RSV and influenza type A.30
Medications frequently used to treat children with croup include nebulized racemic epinephrine, systemic corticosteroids, and inhaled corticosteroids. A recent systematic review evaluating the use of corticosteroids included 35 randomized controlled clinical trials. The conclusion of the analysis is that oral dexamethasone, intramuscular dexamethasone, and nebulized budesonide are each effective in improving symptoms of croup within 6 hours of administration.31 Benefits of treating croup with corticosteroids include a decrease in return office visits, decreased hospitalizations, and a decreased length of stay if hospitalized. Typical dosing of dexamethasone used for croup is 0.6 mg/kg, while the usual dose for nebulized budesonide is 2 mg. Randomized studies evaluating the use of racemic epinephrine versus placebo in croup have demonstrated an improvement in clinical scores for those children suffering from moderate or severe croup.32,33 Usual dosing of nebulized racemic epinephrine is 0.5 ml of 2.25% solution mixed with 2 cc of normal saline. As the onset of action is 10 to 30 minutes with a duration of 2 hours, it is recommended that patients be observed for at least 2 hours after receiving a dose of racemic epinephrine in order to evaluate for clinical deterioration.34
Preparation for pediatric pulmonary emergencies in the office setting includes adequate training for all medical staff, properly sized and working equipment, and medications to help alleviate respiratory distress when indicated. Status asthmaticus, viral bronchiolitis, and croup account for the vast majority of respiratory emergencies encountered in the pediatric office setting. Timely application of proven approaches to assessment and treatment of these illnesses can prevent hospitalization, decrease length of hospitalizations, and save lives.
1. American Heart Association, American Academy of Pediatrics, eds. PALS Provider Manual. Dallas, TX: American Heart Association; 2002.
2. Dolovich MB, Ahrens RC, Hess DR, et al.; American College of Chest Physicians, American College of Asthma, Allergy, and Immunizations. Device selection and outcomes of aerosol therapy: evidence-based guidelines: American College of Chest Physicians/American College of Asthma, Allergy, and Immunology. Chest. 2005;127(1):335-371.
3. Everard ML, Clark AR, Milner AD. Drug delivery from jet nebulisers. Arch Dis Child. 1992;67(5):586-591.
4. Lowenthal D, Kattan M. Facemasks versus mouthpieces for aerosol treatment of asthmatic children. Pediatr Pulmonol. 1992; 14(3):192-196.
5. Amirav I, Newhouse MT. Aerosol therapy with valved holding chambers in young children: importance of the facemask seal. Pediatrics. 2001;108(2):389-394.
6. Helfaer M. Textbook of Pediatric Intensive Care. 3rd ed. Baltimore, MD: Williams and Wilkins; 1996.
7. Gorelick MH, Stevens MW, Schultz TR, Scribano PV. Performance of a novel clinical score, the Pediatric Asthma Severity Score (PASS), in the evaluation of acute asthma. Acad Emerg Med. 2004;11(1):10-18.
8. Carl JC, et al. Comparison of racemic albuterol and levalbuterol for treatment of acute asthma. J Pediatr. 2003;143(6):731-736.
9. Kornberg AE, Zuckerman S, Welliver JR, Mezzadri F, Aquino N. Effect of injected longacting epinephrine in addition to aerosolized albuterol in the treatment of acute asthma in children. Pediatr Emerg Care. 1991;7(1):1-3.
10. Victoria MS, Battista CJ, Nangia BS. Comparison between epinephrine and terbutaline injections in the acute management of asthma. J Asthma. 1989;26(5):287-290.
11. Payne DN, Balfour-Lynn IM, Biggart EA, Bush A, Rosenthal M Subcutaneous terbutaline in children with chronic severe asthma. Pediatr Pulmonol. 2002;33(5):356-361.
12. Simons FE, Gillies JD. Dose response of subcutaneous terbutaline and epinephrine in children with acute asthma. Am J Dis Child. 1981;135(3):214-217.
13. Moler FW, Hurwitz ME, Custer JR. Improvement in clinical asthma score and PaC02 in children with severe asthma treated with continuously nebulized terbutaline. J Allergy Clin Immunol. 1988;81(6):1101-1109.
14. Montgomery VL, Eid NS. Low-dose beta-agonist continuous nebulization therapy for status asthmaticus in children. J Asthma. 1994;31(3):201-207.
15. Papo MC, Frank J, Thompson AE. A prospective, randomized study of continuous versus intermittent nebulized albuterol for severe status asthmaticus in children. Crit Care Med. 1993;21(10):1479-1486.
16. Guidelines for the Diagnosis and Management of Asthma - Update on Selected Topics, National Heart, Lung, and Blood Institute. National Asthma and Education and Prevention Program. 2002. Available at: http://www.nhlbi.nih.gov/guidelines/asthma/index.htm. Accessed October 18, 2005.
17. Becker JM, Arora A, Scarfone RJ, et al. Oral versus intravenous corticosteroids in children hospitalized with asthma. J Allergy Clin Immunol. 1999;103(4):586-590.
18. Rowe BH, SpoonerC, Ducharme FM, Bretzlaff JA, Bota GW. Early emergency department treatment of acute asthma with systemic corticosteroids. Cochrane Database Syst Rev. 2001;(1):CD002178.
19. Barnes PJ. Effect of corticosteroids on airway hyperresponsiveness. Am Rev Respir Dis. 1990;141(2 Pt 2):S70-S76.
20. Rachelefsky G. Treating exacerbations of asthma in children: the role of systemic corticosteroids. Pediatrics. 2003;112(2):382-397.
21. Global Strategy for Asthma Management and Prevention. National Institutes of Health. National Heart, Lung and Blood Institute. 2002. NIH Publication No 02-3659.
22. Plotnick LH, Ducharme FM. Acute asthma in children and adolescents: should inhaled anticholinergics be added to beta(2)-agonists? Am J Respir Med. 2003;2(2):109-115.
23. Qureshi F, Pestian J, Davis P, Zaritsky A. Effect of nebulized ipratropium on the hospitalization rates of children with asthma. N Engl J Med. 1998;339(15):1030-1035.
24. Zorc JJ, Pusic MV, Ogborn CJ, Lebet R, Duggan AK Ipratropium bromide added to asthma treatment in the pediatric emergency department. Pediatrics. 1999;103(4 Pt 1):748-752.
25. Craven D, Kercsmar CM Myers TR, O'riordan MA, Golonka G, Moore S. Ipratropium bromide plus nebulized albuterol for the treatment of hospitalized children with acute asthma. J Pediatr. 2001;138(1):51-58.
26. Patel H, Piatt R, Lozano JM, Wang EE. Glucocorticoids for acute viral bronchiolitis in infants and young children. Cochrane Database Syst Rev. 2004;(3):CD004878.
27. King VJ, Viswanathan M, Bordley WC, et al. Pharmacologic treatment of bronchiolitis in infants and children: a systematic review. Arch Pediatr Adolesc Med. 2004;158(2):127-137.
28. Hartling L, Wiebe N, Russell K, Patel H, Klassen TR Epinephrine for bronchiolitis. Cochrane Database Syst Rev. 2004;(1):CD003123.
29. Mallory MD, Shay DK, Garrett J, Bordley WC. Bronchiolitis management preferences and the influence of pulse oximetry and respiratory rate on the decision to admit. Pediatrics. 2003;111(1):e45-e51.
30. Denny FW, Murphy TF, Clyde WA Jr, Collier AM, Henderson FW. Croup: an 11-year study in a pediatric practice. Pediatrics. 1983;71(6):871-876.
31. Russell K, Wiebe N, Saenz A, et al. Glucocorticoids for croup. Cochrane Database Syst Rev. 2004;(1):CD001955.
32. Kristjansson S, Berg-Kelly K, Winso E. Inhalation of racemic adrenaline in the treatment of mild and moderately severe croup. Clinical symptom score and oxygen saturation measurements for evaluation of treatment effects. Acta Paediatr. 1994;83(11):1156-1160.
33. Ledwith CA, Shea LM, Mauro RD. Safety and efficacy of nebulized racemic epinephrine in conjunction with oral dexamethasone and mist in the outpatient treatment of croup. Ann Emerg Med. 1995;25(3):331-337.
34. Rizos JD, DiGravio BE, Sehl MJ, Tallon JM. The disposition of children with croup treated with racemic epinephrine and dexamethasone in the emergency department. J Emerg Med. 1998;16(4):535-539.
Suggested Equipment for Office Respiratory Emergencies in Children
Suggested Medications for Office Respiratory Emergencies in Children
Pediatric Asthma Severity Score