The use of high-flow nasal cannula and noninvasive ventilation has become increasingly common in emergency medicine as a first-line treatment of pediatric patients with respiratory distress secondary to asthma and bronchiolitis. When implemented in clinical practice, close monitoring of vital signs and ventilation parameters is warranted to identify possible signs of respiratory failure. This issue provides evidence-based recommendations for the appropriate use of noninvasive ventilation modalities in pediatric patients including high-flow nasal cannula, continuous positive airway pressure, and bilevel positive airway pressure in the setting of acute respiratory distress. Contraindications and complications associated with these modalities are also discussed.
A 2-month-old girl, born full-term without complications, presents to your ED in the middle of December. According to her mother, she has had 3 days of cough and congestion, as well as decreased feeding. The mother took her to the primary care physician’s office earlier in the day because she noticed that the girl's breathing had become extremely fast. On examination, the primary care physician noted wheezing and retractions, with an increased respiratory rate, and she recommended the mother take the child to the ED. The infant's initial vital signs are: temperature, 37.5°C (99.5°F); heart rate, 170 beats/min; respiratory rate, 74 breaths/min; blood pressure, 82/60 mm Hg; and oxygen saturation, 89% on room air. She weighs 5 kg. Her physical examination is notable for nasal congestion with grunting, tachypnea, and subcostal and supraclavicular retractions. She also has dry mucous membranes and a capillary refill of 3 seconds. Oxygen is provided by nonrebreather mask, and IV access is obtained. Nasal suctioning is performed without much change in her respiratory status. You make the decision to use high-flow nasal cannula as the initial form of respiratory support, with the following settings: FiO2, 40%; flow rate, 5 L/min. After about an hour on high-flow nasal cannula, the infant's vital signs are relatively unchanged. What are the signs of failure of high-flow nasal cannula? Is there a maximum flow rate above which this modality is not as effective, and how should it be titrated in pediatric patients? Are higher rates more likely to cause harm?
On a mid-spring day, a 5-year-old boy with a past medical history significant for asthma presents with audible wheezing and respiratory distress. His mother states that he had been playing in the backyard with his sister yesterday, and his symptoms have been persistent since then. Despite using his albuterol nebulizer every 4 hours at home, he has still been coughing and wheezing. When reviewing his history, you note that he has been admitted to the PICU for asthma exacerbations, with the most recent admission being 3 months ago. His vital signs are: temperature, 36.5°C (97.7°F); heart rate, 130 beats/min; respiratory rate, 44 breaths/min; blood pressure, 100/76 mm Hg; oxygen saturation, 93% on room air. He weighs 20 kg. On initial examination, the patient is awake and alert but in severe respiratory distress. He has diminished breath sounds throughout, with substernal and lower intercostal retractions. He cannot speak in full sentences. You immediately order 3 consecutive nebulized albuterol treatments with ipratropium, establish IV access, and administer methylprednisolone. Given the severity of his symptoms, you are considering bilevel positive airway pressure (BPAP) to prevent intubation. What are the optimal settings when initiating BPAP therapy? Can nebulized medications be given through the mask interface with BPAP, and are they still effective? What complications may arise while using BPAP, and is it an effective means of avoiding intubation?
Respiratory disease is one of the most common causes of morbidity in pediatric patients, and acute or impending respiratory failure remains the leading diagnosis for admission to the pediatric intensive care unit (PICU).1 The mainstay of therapy for these patients has traditionally included mechanical ventilation. Inherent to endotracheal intubation and mechanical ventilation is the potential for iatrogenic complications, including upper airway trauma, laryngeal swelling, postextubation vocal cord dysfunction, prolonged sedation and hospitalization, and nosocomial infections.2 For more information on mechanical ventilation in pediatric patients, refer to the July 2020 issue of Pediatric Emergency Medicine Practice, “Mechanical Ventilation of Pediatric Patients in the Emergency Department.”
Noninvasive ventilation (NIV) has become an important tool in pediatric emergency medicine to delay or prevent endotracheal intubation. Initially introduced in the adult and neonatal population, NIV has been used increasingly in the management of pediatric respiratory failure.3,4 High-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BPAP) are the primary forms of NIV used in pediatric patients. Several different device interfaces for NIV exist, and emergency clinicians need to understand the options that are available in their particular clinical setting. While NIV has generally shown good results when used in the management of acute respiratory failure secondary to bronchiolitis and asthma, its role in the management of pneumonia, acute respiratory distress syndrome (ARDS), and other disease processes is less clear.
This issue of Pediatric Emergency Medicine Practice reviews the different types of NIV, cites the indications for their use in the emergency department (ED), and provides evidence-based recommendations for their use in patients with various disease processes.
A literature search was performed in PubMed, Google Scholar, Ovid MEDLINE®, and the Cochrane Database of Systematic Reviews using the search terms: pediatric noninvasive ventilation, high-flow nasal cannula, HFNC, continuous positive airway pressure, CPAP, bilevel positive airway pressure, and BiPAP. A total of 363 abstracts were evaluated, and 177 full-text articles published between 1995 and 2019 were reviewed. Citations within articles were also cross-referenced.
The literature regarding NIV in pediatric patients is limited in the number of prospective studies and randomized controlled trials. Most of the strong evidence for its use comes from neonatal and adult literature. All pediatric-specific Cochrane reviews regarding this topic did not have sufficient evidence to make recommendations.
The introduction of HFNC into pediatric emergency care has offered a less invasive means of improving respiratory distress. In its most basic form, the equipment necessary for HFNC is a source of pressurized oxygen or air, a sterile water reservoir, an insulated or heated circuit, and a nonocclusive cannula interface. The equipment remains an open system, meaning that the cannula interface does not fully obstruct the nostrils. This characteristic distinguishes HFNC from the closed systems used in other NIV modalities (CPAP and BPAP).5 In the existing literature, HFNC is not routinely considered to be NIV and will thus be referred to as HFNC, while other modalities will be referred to as NIV throughout this review. For information on HFNC setup, watch the video at: www.youtube.com/watch?v=BD79VxUlsis
There are several mechanisms by which HFNC is believed to provide respiratory support to pediatric patients. The air or oxygen in HFNC is heated and humidified. Normally, the initial temperature is 1°C to 2°C below body temperature and adjusted for patient comfort. Theoretically, by providing heated and humidified air, the HFNC system allows for greater clearance of secretions, reduced airway obstruction, and decreased energy expenditure. In addition, HFNC can be titrated to higher flow rates than simple nasal cannula. These flow rates can meet and exceed the inspiratory demands of the patient, thus decreasing the work of breathing. Because the patient is not inhaling as much room air through their own inspiratory forces, dilution of the oxygen support provided by nasal cannula is prevented.6 Finally, during rebreathing, HFNC can wash out CO2 that collects in the relatively larger nasopharyngeal dead space in children;7 this washout improves gas exchange and breathing efficiency.5,6
Because HFNC is an open system, it was not regarded initially as a form of positive pressure ventilation, as it was not believed to generate measurable airway pressures. It has now been shown that HFNC can generate some degree of positive end-expiratory pressure (PEEP), thus recruiting alveoli and increasing the functional residual capacity. Nonetheless, the measurement of pressure is highly variable and dependent on leakage around the nasal prongs.8,9 Reports in the literature have shown that there is 3 to 6 cm H2O of PEEP generated, which may help to explain some of the observed clinical benefit.10-12 Unlike CPAP and BPAP, however, this cannot be titrated precisely, so the clinical response of the patient will vary and must be monitored individually.
Flow rates for HFNC can be titrated to as high as 60 L/min to achieve the desired effect. However, the maximum benefit in the pediatric population appears to be at flow rates between 1.5 to 2 L/kg/min.13 When compared with patients treated with HFNC at 3 L/kg/min, there was no significant difference in failure rate, intubation rate, or duration of invasive ventilation or NIV. Additionally, patients with bronchiolitis who were treated with 3 L/kg/min of flow experienced greater discomfort and increased length of stay in the PICU.14
NIV, which includes CPAP and BPAP, consists of an external interface that delivers pressurized gas supplied by a pressure-targeted ventilator.3 There are several different interfaces that can be employed, which are shown in Table 1.15,16 The most important aspect of the equipment is an interface that fits the patient's face correctly. Generally, one should be able to pass a finger between the headgear and the face.17 Without an appropriately sized mask, air leaks around the mask can occur, which lead to patient-ventilator asynchrony that results in insufficient inspiratory flow and treatment failure.18,19 For information on how to set up a BPAP machine, watch the video at: www.youtube.com/watch?v=hXtx0nEoL9E
1. “The patient was not improving on BPAP. I wanted to avoid endotracheal intubation and its associated complications, so I continued management with BPAP.”
Since its introduction in pediatric emergency care, NIV has helped avoid intubation in several patient populations. Despite this, ignoring the signs that indicate when escalation of therapy is necessary can be fatal. When a patient’s respiratory rate is worsening, the PaCO2 is climbing, or intolerance of the interface is preventing adequate ventilation, it may be necessary to perform endotracheal intubation.
5. “The patient was still breathing fast after 5 minutes of BPAP therapy, so I decided it was time to intubate him.”
Troubleshooting for reasons for deterioration after placement of NIV should be systematic. Evaluation of the mask and how well it fits is important. Observe the patient for asynchrony with the machine and the possible etiologies. Examine the patient for complications secondary to initiation. Finally, evaluate the equipment for possible failure. After troubleshooting and evaluating for complications, if NIV still appears to be failing, then intubation may be necessary.
9. “My trauma patient with a Glasgow Coma Scale score of 6 and several pulmonary contusions needed respiratory support. I initiated CPAP since his oxygen saturation was 100%.”
Alteration in mental status (eg, a low Glasgow Coma Scale score) when the patient is not protect-ing his airway requires intubation. This is a contraindication for NIV. Other contraindications to its use include severe craniofacial abnormalities, severe ARDS, untreated pneumothorax, or severe hemodynamic instability.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study is included in bold type following the reference, where available. In addition, the most informative references cited in this paper, as determined by the author, are highlighted.
Daniel Slubowski, MD; Timothy Ruttan, MD, FACEP
Deborah A. Levine, MD; Joshua Nagler, MD, MHPEd
August 2, 2020
September 2, 2023
4 AMA PRA Category 1 Credits™, 4 ACEP Category I Credits, 4 AAP Prescribed Credits, 4 AOA Category 2-A or 2-B Credits.
Date of Original Release: August 1, 2020. Date of most recent review: July15, 2020. Termination date: August 1, 2023.
Accreditation: EB Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. This activity has been planned and implemented in accordance with the accreditation requirements and policies of the ACCME.
Credit Designation: EB Medicine designates this enduring material for a maximum of 4 AMA PRA Category 1 CreditsTM. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Specialty CME: Not applicable. For more information, please call Customer Service at 1-800-249-5770.
ACEP Accreditation: Pediatric Emergency Medicine Practice is also approved by the American College of Emergency Physicians for 48 hours of ACEP Category I credit per annual subscription.
AAP Accreditation: This continuing medical education activity has been reviewed by the American Academy of Pediatrics and is acceptable for a maximum of 48 AAP credits per year. These credits can be applied toward the AAP CME/CPD Award available to Fellows and Candidate Fellows of the American Academy of Pediatrics.
AOA Accreditation: Pediatric Emergency Medicine Practice is eligible for up to 48 American Osteopathic Association Category 2-A or 2-B credit hours per year.
Needs Assessment: The need for this educational activity was determined by a survey of medical staff, including the editorial board of this publication; review of morbidity and mortality data from the CDC, AHA, NCHS, and ACEP; and evaluation of prior activities for emergency physicians.
Target Audience: This enduring material is designed for emergency medicine physicians, physician assistants, nurse practitioners, and residents.
Goals: Upon completion of this activity, you should be able to: (1) demonstrate medical decision-making based on the strongest clinical evidence; (2) cost-effectively diagnose and treat the most critical ED presentations; and (3) describe the most common medicolegal pitfalls for each topic covered.
Discussion of Investigational Information: As part of the journal, faculty may be presenting investigational information about pharmaceutical products that is outside Food and Drug Administration approved labeling. Information presented as part of this activity is intended solely as continuing medical education and is not intended to promote off-label use of any pharmaceutical product.
Faculty Disclosures: It is the policy of EB Medicine to ensure objectivity, balance, independence, transparency, and scientific rigor in all CME-sponsored educational activities. All faculty participating in the planning or implementation of a sponsored activity are expected to disclose to the audience any relevant financial relationships and to assist in resolving any conflict of interest that may arise from the relationship. Presenters must also make a meaningful disclosure to the audience of their discussions of unlabeled or unapproved drugs or devices. In compliance with all ACCME Essentials, Standards, and Guidelines, all faculty for this CME activity were asked to complete a full disclosure statement. The information received is as follows:Dr. Slubowski, Dr. Ruttan, Dr. Levine, Dr. Nagler, Dr. Mishler, Dr. Claudius, Dr. Horeczko, and their related parties report no significant financial interest or other relationship with the manufacturer(s) of any commercial product(s) discussed in this educational presentation.
Commercial Support: This issue of Pediatric Emergency Medicine Practice did not receive any commercial support.
Earning Credit: Two Convenient Methods: (1) Go online to www.ebmedicine.net/CME and click on the title of this article. (2) Mail or fax the CME Answer And Evaluation Form with your June and December issues to Pediatric Emergency Medicine Practice.
Hardware/Software Requirements: You will need a Macintosh or PC with internet capabilities to access the website.
Additional Policies: For additional policies, including our statement of conflict of interest, source of funding, statement of informed consent, and statement of human and animal rights, visit https://www.ebmedicine.net/policies.