CPAP titration in the pediatric population.

Due to an increase in awareness of the consequences of sleep-related breathing problems in pediatric populations, many sleep laboratories are now performing polysomnographic evaluations on patients under 18 years old. While there are many similarities in studying children as compared to adults, there are some unique differences in this population that can influence the diagnosis and treatment of Obstructive Sleep Apnea Syndrome (OSAS). One major difference that can influence polysomnographic outcomes is the behavior of children as compared to adults and these issues can be of particular concern if the study is a Continuous Positive Airway Pressure (CPAP) titration. In order to maximize the ability of technologists to perform CPAP sleep studies on children, an explanation of some differences in OSAS in the pediatric population as well as the consequences of OSAS as compared to adults will be necessary. A CPAP acclimation program designed to improve both the titration outcome and overall patient compliance is also relevant.

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It has been estimated that 7 to 9 % of children snore regularly, with an estimated prevalence of OSAS at 0.7 % in 4 to 5-year-old children. OSAS is a disorder of breathing during sleep characterized by prolonged partial upper airway obstruction (hypopnea) and/or intermittent complete obstruction (apnea) that disrupt normal ventilation during sleep. Reduction of the airway size can create negative airway pressure and paradoxically worsen the obstruction. The most common anatomic factors leading to OSAS in children include large tonsils or adenoids, obesity, micrognathia (small jaw) or other anatomic anomalies and swollen mucous membranes from allergies or upper respiratory infections.

Apneas and hypopneas lead to a drop in oxygen saturations, increase in blood carbon dioxide, and, more commonly in adults with apnea, can cause a full or partial arousal pattern in sleep EEG tracings. In children, it appears that the fragmenting effects of sleep disordered breathing on sleep architecture commonly seen in adults are not as prevalent and sleep architecture is more preserved.

Despite the relative preservation in sleep architecture when these events occur in young children, increased time sleeping can result. In older children, sleepiness is often manifested by behavioral changes and poor school performance (in appropriately aged children). All children are at risk for cardiac and pulmonary effects of recurrent hypoxia and hypercarbia. With time, these abnormalities can become irreversible.

There is increasing evidence that disturbed sleep may be associated with more intrinsic deficits in daytime alertness. Behavioral problems including ADHD and related cognitive executive dysfunction and, perhaps more extrinsically, poor school performance have now been documented in children with suspected poor sleep.

Since adenoid and tonsillar enlargement account for most cases of pediatric obstructive sleep apnea, removal of the adenoids and/or tonsils provides a cure in most instances. Some children may also benefit from nasal CPAP; a treatment more commonly used in adults. Functionally, CPAP acts as a splint to prevent collapse of the pharyngeal tissues. As a precise therapeutic pressure is optimal for successful treatment, CPAP must be titrated to the patient, usually in the setting of an overnight polysomnogram. The major drawbacks to CPAP are poor patient tolerance and poor compliance. In children, these factors can be especially problematic since family dynamics may be an issue. Data in adult populations indicate that if compliance is high over a 3-month period, compliance will remain high. Conversely, if compliance is poor during the initial period of acclimation, the likelihood of long-term compliance decreases. Improvement in long-term compliance has been shown in children who were physically and behaviorally acclimated to CPAP prior to titration.

The success of any CPAP acclimation program for children may be dependent upon the thorough education of both the parent and, if appropriate, the child. The referring physician should explain CPAP to the caregiver. Further education can be accomplished through one-on-one interaction, an educational videotape and discussion of the physician reviewed baseline sleep study, if available. A caregiver understands the necessity of treatment if the cardiopulmonary consequences of untreated obstructed breathing as well as the association with potential behavioral and performance problems are clearly explained. Caregivers may then be more likely to promote strict compliance at home. An explanation of the importance of enforcing nightly CPAP usage is necessary for the caregiver to understand that letting their child sleep without CPAP "just this once" may make it difficult to assure CPAP compliance on subsequent nights.

In addition to education, the acclimation program should include practice with an open nasal mask. The mask must be open to the air to avoid creating extra dead-space that a mask with a closed circuit or mask with any attachment(s) can create. The patient and caregiver are scheduled for a "mask fitting" in the sleep facility approximately one week prior to the CPAP titration. The patient is measured and acclimated to the CPAP mask during the "fitting." Caregivers observe and can be active participants in this process. Once the child is seen wearing the mask comfortably, the caregiver is more easily assured that it is possible to get the mask on the child at home. Be sure to give caregivers and the patient ample opportunity to ask questions and discuss concerns. Provide a means for follow up questions.

Explain the different features available for CPAP users such as alternate masks, heated humidification, ramps and Bi-level modalities. The child and caregiver are sent home with the appropriately sized open mask, headgear and spacer if appropriate. The patient is instructed to "get used to wearing the mask" and the caregivers are informed that simply wearing the mask will not prevent apneic events. Since the mask alone is not therapeutic, it is common for the mask to be removed during practice nights following apneic induced arousals. The open-mask acclimation could include wearing the mask during non-bedtime hours when watching TV or playing in the home. Wearing the open mask around the house may also help the parent to address any social issues or concerns if there are siblings or other children in the house. The child and parent are instructed to have the child actually fall asleep while wearing the mask for one or two nights prior to the CPAP titration study.

The next critical phase of improving compliance begins on the CPAP titration night. Many people benefit from a short period of acclimation to low-pressure CPAP by holding the mask on or close to their nose. The caregiver and patient are informed that the air pressure may be higher if the child awakens during the night. If a child is not developmentally capable of understanding the purpose of CPAP, this awakening may last for quite some time. Prior to the titration, the caregiver is informed that mask removal following an arousal and replacement once the child returns to sleep may not be helpful since this practice will almost certainly cause another arousal and provoke suspicions on the part of the child, further prolonging sleep onset. Ideally, the mask is left on and the pressure is left at therapeutic levels. Temporarily reducing the pressure may be helpful as long as the technologist appropriately returns to previously proven therapeutic levels upon resumption of sleep. In many cases, the use of C-Flex technology is helpful following an arousal. When C-Flex is used, a specialized CPAP unit delivers a personalized pressure based on the patient's flow that provides relief at the beginning of exhalation when the airway is less susceptible to closure. The unit returns to the therapeutic CPAP level prior to the end expiratory phase. Even developmentally delayed patients will often notice an improvement in the ability to breathe on C-Flex or a similar use of Bi-level pressures if a CPAP unit with C-Flex capability is unavailable.

Finally, intense follow up can greatly improve CPAP compliance. Others have shown that compliance is improved when sleep laboratory personnel or the referring physician's office contact the home at least 3 times within the first week of using CPAP. Subsequent contacts should be made once a week, if possible, in the first 3 months of CPAP usage.

Titrating CPAP for pediatric patients admittedly has its specific challenges. The successful completion of this type of sleep study will depend both on the technologist's knowledge of the nature and consequences of OSAS in children and a formal acclimation program. The acclimation program should be designed to maximize the outcome of a CPAP titration and improve overall compliance to CPAP in the patient's home. The pediatric population can be better served and the lives of these children and their families improved through appropriate CPAP education, an appropriate acclimation program, an optimal titration and intense follow up to insure compliance.

by Patrick Sorenson, MA, RPSGT