Educational Aims

The reader will come to appreciate that:

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  Increasing numbers of children are treated with chronic positive end-expiratory pressure (PEEP) at home.

  
  
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  The majority of children have anatomical or functional abnormalities of the upper airways.

  
  
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  Patients should be managed by a paediatric multidisciplinary team with expertise in home PEEP.

Positive end-expiratory pressure (PEEP), also called continuous positive airway pressure (CPAP), consists of the delivery of a constant positive pressure in the airways by means of a noninvasive interface aiming to maintain airway patency throughout the entire respiratory cycle [ ]. PEEP is used in the chronic care of children with anatomical or functional abnormalities of the upper airways in order to correct severe persistent obstructive sleep apnea (OSA) [ ]. These children may have OSA type III, defined by a reduction of the caliber or patency of the upper airways by anatomical abnormalities, or OSA type II, i.e. related to obesity. This review summarizes the most recent clinical experience and optimal care for children treated with chronic PEEP.

The main indication of chronic PEEP is severe persistent OSA after adenotonsillectomy or upper airway surgery despite optimal medical and surgical management, or when these treatments are not feasible or indicated. The majority of these patients have “complex” OSA, or OSA type III, due to anatomical or functional abnormalities of the upper airways as observed in faciocraniosynostosis, malformation of the palate, maxilla or mandible, congenital bone disease, laryngo-tracheo-bronchomalacia or stenosis, vocal cord paralysis, Down syndrome, storage disease, and Prader Willi syndrome [ ]. The majority of these patients are infants or young children, due to the small and more collapsible airways at a young age [ ]. The second group of patients have OSA associated with obesity, also called OSA type II. These patients may have syndromic or idiopathic obesity and are mainly school aged children or adolescents. Only a minority of children have no underlying disease, and thus OSA type I, with persistent OSA after adenotonsillectomy. The number of patients with OSA type II and III is increasing worldwide due to a better screening of OSA in patients with upper airway malformations and the dramatic increase in childhood obesity [ ].

Before proposing chronic non-invasive PEEP, it’s important to know that the treatment may be difficult, impossible, or not indicated in the following situations: impossibility to correct OSA with optimal PEEP, inability to protect the upper airways due to bulbar dysfunction and/or copious secretions, lack of cooperation of the patient and/or the family, uncontrolled gastro-oesophageal reflux or severe aerophagia, anatomical facial abnormalities, recent facial surgery or complications related to the interface [ ].

There is an international consensus to start chronic PEEP in case of severe persistent OSA, defined by an obstructive apnea-hypopnea index (OAHI) > 5 events/hour after adenotonsillectomy or upper airway surgery, in children with OSA type II or III [ ]. Chronic PEEP is preferentially initiated in an elective setting, which implies the screening of patients at risk [ ]. Chronic PEEP may also follow an admission to the pediatric intensive care unit for acute respiratory failure with unsuccessful weaning from invasive ventilation or PEEP [ ]. Chronic PEEP is usually initiated during a short hospitalization with a tendency towards an out-patient or even home setting, depending on the underlying condition, team expertise and local facilities [ ].

The American Academy of Sleep Medicine recommends a titration polysomnography (PSG) to set the optimal PEEP level [ ]. However, a PEEP level set on other criteria, such as symptoms, comfort, overnight pulse oximetry (SpO ₂ ) ± transcutaneous carbon dioxide pressure (PtcCO ₂ ), and/or analysis of the device built-in software data, has also shown to correct OSA symptoms and the AHI [ ]. Mean PEEP level to overcome respiratory events is usually achieved at 8 ± 3 cmH ₂ O following titration with a starting pressure of 4 cm to 5 cm H ₂ O, independently of age and underlying diagnosis. Auto-PEEP, which is a mode that automatically adjusts the level of pressure to the patient’s requirements, may be used in children whose weight is above the minimal weight recommended by the device manufacturer. As in adult patients, auto-PEEP and other “complex” PEEP modes have not shown to be associated with a greater efficacy (decrease of AHI), comfort, or adherence than constant PEEP.

Nasal masks are the most used interface with an adequate fitting and tolerance of the interface having shown to be crucial for chronic PEEP success [ ]. Other interfaces may be indicated in case of poor tolerance or side effects (for example, oronasal mask for patients with mouth leaks or nasal prongs/cushions for older children). It may be difficult to find a well-fitted interface for children with facial deformity. The importance of an appropriately fitted headgear should not be underestimated, especially in children with skull or cranial deformity [ ]. The main interface adverse effects are related to pressure (skin injury, facial deformity), or poor fitting (leaks, mucosal drying, corneal ulcers) [ ].

Numerous devices are available to deliver chronic PEEP. These devices are classified into 3 categories of increasing performance and technicity. Level 1 devices have no internal battery and limited alarms, level II devices have an internal battery, and level III devices are life support ventilators, with internal and external batteries and appropriate alarms even for newborns. The choice of a device is based on the child’s characteristics (weight, underlying disease) and medical needs (clinical stability). Level I devices may thus be used in stable school aged children, whereas level II are recommended for infants. Humidification of inspired air seems associated with a greater comfort and fewer problems with secretions.

Before discharge, all caregivers and patients should receive adequate and comprehensible therapeutic education on chronic PEEP, ideally associated with written support [ ]. In some centres, the families of young infants may receive cardiopulmonary resuscitation [CPR] training and the baby may be placed on an apnoea monitor for the first six months of life. Every education program should include an information on the disease and rationale of PEEP; understanding of the goal and benefits of PEEP; adequate information on the appropriate use and cleaning of the interface, devices, and accessories (humidification); information on the problems and limitations of PEEP and how to deal with them; and information on the follow up and outcome of PEEP. This therapeutic education is a continuous process and should be evaluated and reinforced if needed at every visit.

The optimal follow up for children treated with chronic PEEP has not been validated. Follow up schedule depends on the patient’s age, diagnosis, local facilities, and family support. A planned visit one month after PEEP initiation followed by regular visits every 3–6 months is usually considered as a minimum [ ]. A follow up sleep study to check PEEP settings is useful after each intervention (e.g. change in ventilator settings, upper airway or maxillofacial surgery, orthodontics) that may affect the severity of OSA. In stable and adherent patients, an analysis of built-in software with simultaneous monitoring of overnight gas exchange (SpO ₂ ± PtcCO ₂ ) is informative [ ]. A PSG or polygraphy with PEEP is useful in case of suboptimal control of OSA with standard follow up visits. Telemonitoring is feasible and may reduce hospital visits and improve PEEP adherence while limiting side effects [ ].

Adherence should be evaluated regularly based on objective data (built-in software data) and represents one of the most important challenges for assessing the efficacy of chronic PEEP [ ]. In children, it seems crucial to target a PEEP use during the entire period of nocturnal sleep, as respiratory events usually predominate at the end of sleep time. Numerous factors related to the patient and the family may impact adherence, underlining the importance of individually adapted strategies in the setting of a good therapeutic relationship with the child and family/carers.

Chronic PEEP has shown to correct or improve OSA, as well as academic function and behaviour, with benefits on blood pressure, cardiovascular stress and metabolic dysfunction being more inconclusive.

The possibility of weaning represents a major characteristic of children treated with chronic PEEP, especially those with OSA type III [ ]. Indeed, 6 to 40% of children may be weaned from chronic PEEP because of spontaneous improvement with age (physiological growth) or after an intervention (orthodontic treatment, upper airway or maxillofacial or neurosurgery). Weaning is less common for patients with OSA type II because sustained weight loss, which represents the most logical and efficient treatment, is rarely obtained or sufficient.

Concerning PEEP failure, it is important to distinguish “non adherence”, which itself lacks clarity in children, and “inefficacy”. Management of PEEP failure should follow a rigorous evaluation of (1) technical issues such as the detection and correction of unintentional leaks; (2) clinical ineffectiveness of treatment; (3) behavioural and psychosocial issues; and (4) domestic environment and inadequate support. This underlines the importance of a thorough evaluation by a multidisciplinary team comprising from a medical and dental perspective a paediatric pulmonologist, an ENT surgeon, a maxillofacial surgeon, a neurosurgeon and an orthodontist. They are often joined by specialist nurses, respiratory therapists and scientific officers contingent upon expertise, resources available and local practices. Depending on the underlying disease, different therapeutic options may be proposed such as a palatal plate, a nasopharyngeal airway, mandibular distraction osteogenesis, glossopexy, for infants with Pierre Robin syndrome. High flow nasal cannula may be an alternative to PEEP in non-adherent children and adolescents with OSA type II or III [ ]. In selected non-adherent adolescents with Down syndrome, removal of lingual tonsils or tongue base reduction surgery and hypoglossal nerve stimulation may be effective alternatives to chronic PEEP [ ]. Finally, a tracheotomy represents the ultimate rescue therapy for children with severe OSA.

Conclusion

The number of children treated with chronic PEEP is increasing worldwide with expanding indications, such as OSA type III, due to a better screening of these patients and improvements in equipment and interfaces. Even if there are consensus views on criteria for PEEP initiation, optimal follow-up and monitoring, and weaning, validated criteria are lacking. Most importantly, patients should managed by a pediatric multidisciplinary and experienced team having expertise in the underlying disorders, sleep breathing assessment and chronic PEEP therapy.

Future directions for research

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  Validation of initiation and weaning criteria for PEEP in chronic care

  
  
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  Reaching consensus on the frequency, monitoring and methods of optimal follow up (including telemedicine) through infancy and childhood.

  
  
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  Management of PEEP failure and consideration of the timing and appropriateness of alternative treatment options.

  
  
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  Qualitative research on the benefits of chronic PEEP on quality of life and patient/caregiver-related health outcomes.