Pediatric noninvasive ventilation (NIV) had its first major breakthrough in 1928 with the development of the Drinker-Shaw “iron lung.” The then state-of-the-art negative-pressure ventilator was first used at Children’s Hospital Boston, mostly to treat children suffering from polio. Later, in 1931, John Emerson remodeled the iron lung and its use was crucial in the treatment of polio.1
Negative-pressure ventilators lost their attraction as the primary application of noninvasive ventilatory support due to patient immobility, lack of support for anatomic airway obstruction, and bulky size. Since the late 1980s, NIV technology has come to fruition and has significantly changed the field of respiratory/critical care medicine. Noninvasive ventilation provides ventilatory support through the patient’s nose and/or mouth by utilizing a mask or nasal prongs.1 In many clinical situations, NIV eliminates the need for an artificial airway, thereby avoiding the associated risks of invasive ventilation, improving patient comfort, preserving airway defense/clearance mechanisms,2 and requiring the use of less sedation.
There is very little research on use of NIV in pediatric patients. The research on NIV is mostly in the adult population, but there is growing support for its use in pediatric patients who present with acute/chronic respiratory failure,1 postextubation respiratory support, neuromuscular disease, cystic fibrosis, skeletal malformations, or hypoventilation syndromes.
The goals of using NIV are very basic. Some of the common goals include overcoming anatomical airway obstructions, reducing atelectasis, decreasing work of breathing, improving V/Q mismatching, and preventing (re)intubation. Strategic use of NIV can reduce the need for endotracheal intubation or the surgical placement of a tracheostomy tube. Because of its ability to anticipate, apply, manage, and wean, pediatric NIV is key to reducing the need for intubation.
Why NOT NIV?
Not all children are good candidates for NIV. One of the largest contraindications for NIV in children is a level of consciousness that would not allow the child to protect his airway if vomiting occurred. The increased risk for aspiration supersedes the benefits of NIV. Other contraindications include facial trauma, pneumothorax, complete upper airway obstruction, and severe hemodynamic instability.2
Skin breakdown can be a major sequela of NIV. This can be caused by applying the interface too tightly to the patient’s face. Skin breakdown can be as simple as mild erythema, or full-blown skin necrosis. The easiest way to prevent skin breakdown is to apply the interface with the least amount of pressure necessary to achieve the desired level of CPAP/bilevel PAP and to check the patient’s skin at least once per shift.
Triggering the ventilator can be problematic for some pediatric patients. Some patients are too weak or too small to effectively and consistently trigger the ventilator. This can lead to the patient being “locked out” of the machine, and cause more work of breathing.
Also, in some cases the child will be so uncooperative and/or noncompliant that attempting to apply NIV will produce more anxiety and possibly more hemodynamic instability.
Types of NIV
There are two types of NIV: continuous positive airway pressure and bilevel positive airway pressure. CPAP delivers a predetermined level of pressure to the patient’s airway. This is used to overcome anatomical obstructions, decrease atelectasis, and improve oxygen saturation. Most CPAP machines do not have an apnea backup feature built in, so strict hemodynamic monitoring should be in place if used in a clinical setting. Bilevel positive airway pressure has several clinical features that make it different from CPAP: bilevel PAP incorporates the use of an inspiratory pressure (IPAP) as well as expiratory pressure (EPAP), which is the same as CPAP. The IPAP is the pressure that is delivered during the patient’s inspiratory effort, and will determine the tidal volume. The EPAP will have the same effect as CPAP. The numerical difference between the IPAP and the EPAP is the amount of pressure support the patient is receiving. Bilevel PAP also has a set backup rate and inspiratory time, which will only affect ventilation if the patient becomes apneic. One of the primary uses for bilevel PAP is to decrease work of breathing. Of course, there are numerous conditions and situations that fit into each category, and each type of NIV might be appropriate for one patient and not for another.
Indications for NIV
Respiratory Failure. The primary indication of NIV in the pediatric patient is respiratory failure with associated hypercapnia.2 There are numerous causes for respiratory failure in children (see Table 1). The goal of NIV in the treatment of acute respiratory failure is to decrease V/Q mismatching primarily due to alveolar collapse.
Table 1. Indications for pediatric noninvasive ventilation (adapted from da Silva et al2).
*Primarily for teenage patients
Once the shunting has been reduced, normal gas exchange should occur, reducing the degree of hypoxemia and hypercarbia. The primary assessment of the child in respiratory failure reveals tachypnea or hypopnea (depending on the nature of the respiratory failure), hypoxemia, the use of accessory muscles, varying levels of consciousness, and an overall poor clinical presentation. Arterial blood gas analysis is always helpful to determine the level of hypercarbia, but is not always available. Sometimes a venous blood gas (VBG) must be obtained, and initial management must be based on those results. Venous blood gases should not be substituted for arterial blood gases for the initiation of mechanical ventilation, although clinically reliable conclusions can be made with VBG analysis.3
Pediatric Chronic Lung Disease. Although there are no major studies focusing on pediatric chronic lung disease and NIV,2 NIV is used extensively in this patient population. Children might have suffered from bronchopulmonary dysplasia as a neonate, or have been ventilator dependent for any number of reasons, and, therefore, can present with chronic lung disease later in life. As with adults who have an acute exacerbation of COPD, the use of NIV in the pediatric patient with chronic lung disease can reduce the need for intubation, alleviate respiratory acidosis, and decrease the overall work of breathing.
Skeletal Malformations of the Chest Wall. There are several skeletal malformations of the chest wall that can require the use of NIV to assist with breathing. Anatomic changes in the chest wall can produce restrictive lung disease, leading to numerous oxygenation and ventilation issues. Inspiration can become difficult, causing limitations in deep breathing and coughing. This can increase the risk of infection due to lack of secretion clearance.2 Noninvasive ventilation can augment the inspiratory effort, decreasing the work of breathing for the patient.
Neuromuscular Disease. Children with neuromuscular disease can develop acute respiratory failure extremely quickly. Common forms of pediatric neuromuscular disease are muscular dystrophy; spinal muscular atrophy (SMA), types I, II, and III; spina bifida; and juvenile myasthenia gravis. The lack of muscle control and strength can lead to an inability to clear secretions from the tracheobronchial tree.4 This can cause acute respiratory failure, bringing about the need for intubation to assist with ventilation and secretion management. To avoid intubation, it has been shown that the use of NIV can reduce the work of breathing and improve airway clearance by keeping intact natural cilia function. It may allow for speaking and swallowing, leading to an increase in overall patient comfort. Studies have suggested that NIV is an effective therapeutic approach to treat children with neuromuscular disease who are in acute hypoxemic respiratory failure.4
Other Indications. Studies also have shown that NIV is beneficial in postoperative liver transplantation,5 postoperative bilateral lung transplantion,6 cystic fibrosis, congenital central hypoventilation syndrome, and Prader-Willi syndrome.7
Choosing the proper interface is arguably the most important aspect of successful pediatric NIV. Children in respiratory distress can become extremely anxious. They are in a strange environment (ICU, ED, etc), and sometimes their parents are not present during the event to help calm them. When the health care team establishes the need for NIV, choosing an interface that will deliver the support needed, while not adding to the patient’s anxiety, is the key to success.
Table 2. Interfaces for pediatric NIV (Only a partial list of available products).
There is a lack of appropriate pediatric interfaces7 that are commercially available. One way around this is to adapt adult masks to fit the pediatric patient. Although there are only a few Food and Drug Administration-approved NIV interfaces for children, some smaller adult masks and adult nasal masks can be used very effectively as pediatric full face masks.8 Finding an interface that fits properly is crucial to minimizing air leaks and maximizing the effects of NIV.9 Respironics, Fisher & Paykel, and ResMed make several adult nasal masks that could be adapted for pediatric use (Table 2).
Using full face masks on children must be done with caution. The risk for aspiration is increased if the child is unable to remove the mask if they vomit.8 This leads some to believe that nasal NIV is safest for children. A chin strap can be tried if there is excessive leak with a nasal mask.
The type of headgear used to keep the mask on the child is also key for successful NIV. Elastic straps with Velcro are suitable in most cases. Other times a bonnet type of cap is necessary to achieve a proper fit. If the cap is too large for the child’s head, the cap can be oversewn by wrapping the straps around the head until the cap has a more appropriate fit.
Several ventilators are capable of performing pediatric NIV. The Respironics V60 is FDA approved for patients weighing greater than 10 kg, and can compensate up to 240 LPM of flow. Other ventilators capable of delivering pediatric NIV include CareFusion’s Avea, the Puritan Bennett 840, and the Draeger Evita XL and Servo-i. Many of these ventilators can provide care for adult, pediatric, and neonatal patients. Each health care institution may find one ventilator more accommodating for all its needs over another.
The Portalung is the modern day iron lung It is a negative-pressure ventilator that is interfaced with the Respironics NEV-100 or Emerson 33-CR ventilators.10 It is considered to be an efficient ventilator because it is user friendly and portable.
The use of noninvasive ventilation in children has been slowly developing since the early 20th century. The effectiveness of its use is widely known but underinvestigated. More large, multicenter clinical trials are needed to achieve a clear, concise picture on the best way to manage pediatric NIV. Until then, the use of proper clinical judgment, patient selection, and careful management is the best way to deliver the best possible care.
Brendan Lillie, BS, RRT-NPS, is a staff respiratory therapist at Newton-Wellesley Hospital in Newton, Mass. For further information, contact [email protected]
- Cheifetz I. Invasive and noninvasive pediatric mechanical ventilation. Respir Care. 2003;48:442-58.
- da Silva DC, Foronda FA, Troster EJ. [Noninvasive ventilation in pediatrics]. J Pediatr (Rio J). 2003;79(Suppl 2):S161-68. Portuguese.
- Malinoski DJ, Todd SR, Stone S, Mullins RJ, Schreiber MA. Correlation of central venous and arterial blood gas measurements in mechanically ventilated trauma patients. Arch Surg. 2005;48:1122-5.
- Piastra M, Antonelli M, Caresta E, Chiaretti A, Polidori G, Conti G. Noninvasive ventilation in childhood acute neuromuscular respiratory failure: a pilot study. Respiration. 2006;73:791-8.
- Chin K, Uemoto S, Takahashi K, et al. Noninvasive ventilation for pediatric patients including those under 1-year-old undergoing liver transplantation. Liver Transp. 2005;11:188-95.
- Rocco M, Conti G, Antonelli M. Non-invasive pressure support ventilation in patients with acute respiratory failure after bilateral lung transplantation. Intensive Care Med. 2001;27:1622-6.
- Markstrom A. Non-invasive ventilation in children. European Respiratory Disease. 2007; pg 27-30.
- Flint K, D’Andrea L. Best practices for pediatric PAP therapy. Advance for Respiratory and Sleep Medicine. September 2010. Available at: http://respiratory-care-sleep-medicine.advanceweb.com/~. Accessed November 12, 2010.
- Jaber S, Chanques G, Jung B. Postoperative noninvasive ventilation. Anesthesiology. 2010;112:453-61.
- The Porta-Lung provides non-invasive ventilator support, offering the same level of efficiency as an iron lung, in a lightweight portable unit. Available at: www.portalung.com. Accessed November 12, 2010.