Polysomnography (PSG) is a crucial diagnostic tool in sleep medicine for both adults and pediatrics [1]. While home sleep apnea tests and other tracking devices are increasingly used in adult populations, PSG remains particularly valuable for pediatric patients due to the complex presentation of sleep-related disorders in this group [1-3]. Sleep-related diseases are highly prevalent among children, including obstructive sleep apnea syndrome (OSAS), snoring, and excessive daytime sleepiness [4]. For both children and adults, PSG provides invaluable insight into sleep physiology, enabling clinicians to diagnose and plan treatment [1].

In children, PSG is particularly valuable for diagnosing respiratory disturbances like OSAS and central apneas, as well as other sleep disorders that can impact overall health, development, and quality of life. PSG offers detailed, simultaneous recording of physiological parameters such as breathing patterns, muscle activity, and oxygen saturation, providing a more comprehensive view than history or physical examination alone, which may not adequately suggest sleep apnea in pediatric cases [5,6]. PSG can be used to diagnose a variety of pediatric sleep-related disorders (Table 1). In addition to diagnosis, PSG plays a key role in pre- and postoperative evaluations, such as determining residual or recurrent airway obstruction after tonsillectomy and adenoidectomy (T&A), and in assessing outcomes to inform further treatment plans, including continuous positive airway pressure (CPAP) titration studies [1]. Furthermore, pediatric PSG is essential for evaluating non-respiratory diseases including neuromuscular disorders. This review summarizes the primary indications for pediatric PSG, with a particular focus on OSAS, underscoring its critical role in assessing pediatric sleep health and guiding clinical management.

Pediatric OSAS is a primary indication for PSG due to its significant impact on children’s overall health and development [7]. While habitual snoring and labored breathing during sleep are common symptoms, they are not always indicative of OSAS, making PSG the gold standard for definitive diagnosis. The American Academy of Pediatrics and American Thoracic Society recommend PSG for children exhibiting clinical signs suggestive of OSAS to obtain objective data that patient’s history alone cannot reliably provide [7-9]. In pediatric PSG, obstructive apnea is defined as a complete cessation of airflow lasting at least two breaths despite continued respiratory effort, and hypopnea is characterized by a partial reduction in airflow accompanied by oxygen desaturation or arousal. The obstructive apnea-hypopnea index quantifies the frequency of events per hour, with more than one event per hour typically considered abnormal in children [10,11].

PSG data offer comprehensive insights into the severity and physiological impact of OSAS, which can guide treatment planning. PSG records respiratory parameters such as airflow, respiratory effort, and oxygen saturation, along with electroencephalogram to assess sleep stage and arousal response. The detailed information derived from PSG is critical to distinguishing OSAS from primary snoring [7]. Moreover, understanding the severity and specific nature of apneic events helps predict potential risks and complications, such as impaired neurocognitive function or cardiovascular morbidity [8,12]. Given that OSAS in children often presents with behavioral issues, PSG is also essential to avoiding misdiagnosis as attentiondeficit/hyperactivity disorder or other behavioral disorders. Accurate diagnosis through PSG enables targeted treatment, improving both quality of life and developmental outcomes in affected children.

While T&A remains the primary treatment for pediatric OSAS, CPAP therapy serves as a valuable option for children who are ineligible for T&A or continue to experience OSAS symptoms postoperatively without an obvious anatomical target [7]. CPAP usually report successful therapeutic results, but adherence of CPAP in children with SDB reported as 11% to 75% [7]. Accurate titration of CPAP is essential for effective therapy, and PSG serves as the standard method to determine optimal pressure settings. Full-night PSG-based titration studies allow clinicians to gradually adjust CPAP levels, ensuring that airway patency is maintained throughout various sleep stages, including rapid eye movement (REM) sleep, where muscle tone reduction often exacerbates OSAS. An initial CPAP pressure is set, typically starting at 4 cm H₂O for pediatric patients, to ensure the upper airway remains open. The titration process involves gradually increasing the CPAP pressure to eliminate respiratory effort-related arousals, apneas, hypopneas, and snoring [13]. Continuous monitoring is essential throughout the titration night to observe the patient’s response to pressure changes and ensure the upper airway remains open. The optimal CPAP pressure is determined when obstructive respiratory events are eliminated, or the recommended maximum CPAP pressure is reached [13]. In pediatrics, immediate or abrupt pressure adjustments can lead to discomfort and subsequent poor adherence to CPAP therapy [14,15]. It might be terrifying and upsetting for a child to receive CPAP for the first time in the middle of the night [7].

CPAP titration PSG not only addresses the therapeutic pressure levels needed to mitigate apneic events but also provides insight into potential side effects, such as skin irritation or aerophagia, which can affect tolerance. Data from PSG allow clinicians to adjust CPAP settings, balancing efficacy with comfort to improve long-term compliance. In cases with more complex respiratory patterns, such as those involving hypoventilation or persistent obstructive events despite initial CPAP, PSG-based titration supports the adaptation of advanced modes of positive airway pressure, such as bilevel positive airway pressure, to ensure adequate ventilation [15].

T&A is the first-line surgical treatment for pediatric OSAS in patients with significant adenotonsillar hypertrophy. PSG normalization was reported in 79% of early adenotonsillectomy group and 46% of watchful waiting group [7]. The effects of T&A in treating pediatric OSA were discussed in several studies [16-19]. Preoperative PSG is useful in evaluating the severity of OSAS and identifying any perioperative risks, particularly in high-risk populations such as children with obesity, Down syndrome, or craniofacial abnormalities. In addition, patients under 3 years of age with severe OSAS, cardiac complications of OSAS, current respiratory infection, and neuromuscular disorders are at high risk [7]. Preoperative PSG provides a baseline apnea-hypopnea index, nocturnal hypoxemia, hypercapnia, and associated respiratory disturbances, all of which inform perioperative monitoring and intervention plans. Close monitoring of hypoxemia and hypercarbia is necessary for high-risk patients after T&A [7].

Postoperative PSG is recommended for assessing T&A efficacy and detecting residual OSAS, especially in patients with persistent symptoms or high-risk factors for incomplete resolution. High risk factors for residual OSAS after T&A include obesity, older age (more than 7 years) at the time of surgery, severe preoperative OSAS, asthma in nonobese, craniofacial and mandibular anomalies [7]. Studies indicate that 20%-40% of children may exhibit residual OSAS after T&A, which PSG can help identify through objective measurements. The success rate of obese OSAS patients after T&A is only 45% [7]. In children with high risk for residual OSAS, persistent snoring, obstructive breathing, or desaturations after T&A, PSG-guided re-evaluation supports timely and appropriate treatment modifications, such as CPAP, further surgical interventions, or adjunctive therapies like mandibular advancement devices [20]. Additionally, PSG findings can reveal whether positional therapy or weight management strategies are warranted as part of the postoperative care plan [21].

For high-risk pediatric OSAS patients, PSG is instrumental in identifying complications that may necessitate prolonged monitoring and follow-up. Given the potential for postoperative airway obstruction, especially in younger or medically complex patients, PSG allows clinicians to safely evaluate recovery and make data-driven decisions about long-term treatment to prevent further morbidity [7].

In addition to OSAS, pediatric PSG is indicated for the assessment of central apnea, periodic breathing, and central hypoventilation syndromes. These conditions, characterized by pauses in breathing due to central nervous system dysregulation, are particularly relevant in neonates and infants or in children with neuromuscular or neurological conditions [10]. Central hypoventilation syndromes, such as congenital central hypoventilation syndrome, present significant risks as they manifest with prolonged apneic events predominantly during sleep [22]. PSG, along with capnography, is critical for identifying and managing these conditions, especially since they may go undetected through daytime evaluations alone [10,22].

Children with neuromuscular disorders often experience respiratory muscle weakness, putting them at risk for sleep-disordered breathing [23]. When growth retardation, developmental progression, daytime symptoms (such as headaches or drowsiness), pulmonary dysfunction, the advent of daytime hypercapnia, polycythemia, or heart failure are present, PSG can be used to diagnose sleep-disordered breathing [23,24].

PSG is used in these cases to assess nocturnal hypoventilation, which is exacerbated during REM sleep due to decreased muscle tone [25,26]. The study provides crucial information on respiratory support needs, including the initiation of non-invasive ventilation for patients with significant nocturnal hypoventilation. As these children may not exhibit overt symptoms of respiratory distress, PSG data are essential for timely intervention, preventing complications such as cor pulmonale and failure to thrive [25,26].

Pediatric patients with chronic lung diseases, such as bronchopulmonary dysplasia or cystic fibrosis, often require PSG to evaluate for nocturnal hypoxemia or hypercapnia [27]. Despite normal oxygenation during the day, sleep can lead to reduced oxygen levels and ventilation inefficiencies, particularly in REM sleep [27]. PSG enables the titration of supplemental oxygen during sleep and helps clinicians set target oxygen levels, supporting growth and reducing long-term complications in these patients [15].

For children with severe respiratory conditions, such as neuromuscular disorders or chronic lung disease, who require mechanical ventilatory support, PSG is instrumental in tailoring ventilator settings to each patient’s specific needs [26]. Ventilators are used in cases requiring more precise control of both inspiratory and expiratory pressures to support weakened respiratory muscles [26]. PSG allows for the continuous monitoring of various physiological parameters, including oxygen saturation, end-tidal CO2, and respiratory effort, providing a comprehensive view of the child’s respiratory status during sleep [25].

In ventilator titration studies, PSG data guide the adjustment of inspiratory pressures to support adequate airflow while minimizing risks associated with overventilation, such as barotrauma or hypocapnia. Additionally, PSG aids in monitoring CO2 levels, which is especially critical in patients prone to hypoventilation during REM sleep. For children transitioning to home ventilation, PSG ensures that the settings established in the sleep lab provide stable oxygenation and ventilation, minimizing the risk of nocturnal hypoxemia or hypercapnia and facilitating a safer, more effective home care regimen [28].

A newborn or infant who needs continuous ventilation while they wait for their airway to enlarge enough to support airway reconstruction may have a tracheostomy. Children who have a tracheostomy tube capped can breathe well when they are awake, but when they sleep, muscle weakness can cause upper airway obstruction [29].

In cases where tracheostomy is considered for removal, PSG helps assess the child’s ability to maintain adequate ventilation and airway patency without the tracheostomy tube [28]. Patients who can tolerate a tracheostomy cap while awake are candidates for tracheostomy decannulation [29]. It may also be helpful to progressively reduce size of the tracheostomy tube prior to PSG. PSG is initially monitored with the tracheostomy cap open. During the PSG, the tracheostomy is capped to simulate decannulation conditions, and parameters such as respiratory effort, oxygenation, and end-tidal CO2 levels are monitored [29]. For chronic lung disease, oxygen should be given through a nasal cannula at a low flow rate if required. This allows clinicians to safely evaluate decannulation readiness while minimizing risk [28].

PSG may be utilized when parasomnia symptoms overlap with other sleep-related disorders, such as OSAS or nocturnal seizures [1]. PSG, combined with video monitoring and good documentation, can help distinguish parasomnias from seizures or other pathological nocturnal events, aiding in accurate diagnosis and treatment planning [1,30].

In cases of suspected periodic limb movement disorder (PLMD), PSG can confirm diagnosis by quantifying limb movements during sleep [1]. PSG is especially useful in young children or those unable to reliably report symptoms, as it provides objective evidence of movement-related sleep disruption [31].

Children are naturally sleepy and as they reach puberty, they sleep more [32]. Insufficient sleep or poor sleep hygiene should be checked through history taking or sleep diaries. PSG with a multiple sleep latency test (MSLT) is indicated for children presenting with excessive daytime sleepiness unaccounted for by poor sleep hygiene or insufficient sleep. PSG evaluates for underlying conditions like OSAS or narcolepsy, with MSLT helping to confirm a narcolepsy diagnosis when short sleep latency and sleep-onset REM periods are observed in multiple naps [33].

PSG in pediatric populations has inherent limitations and requires specific technical considerations to maximize its utility [1]. It has limited clinical relevance in evaluating insomnia or circadian rhythm disorders unless there is concomitant sleep-disordered breathing or PLMD. As a one-night study, PSG may fail to capture infrequent nocturnal events and is subject to the “first-night effect,” where unfamiliar environments reduce sleep quality [34]. Although single-night variability in respiratory parameters is generally minimal, diminished total sleep time or REM proportion may necessitate repeat testing.

Creating a child-friendly sleep laboratory environment is crucial, with accommodations for caregivers and strategies to alleviate patient anxiety, such as familiar items from home, pre-visit tours, and detailed preparation using age-appropriate language [35]. Pediatric sleep technologists trained in child care and distraction techniques are essential for successful studies, even in challenging cases [1].

Although performing PSG in all pediatric patients is challenging, it should be strongly recommended in specific cases: high-risk children undergoing T&A, including those under 3 years of age with severe OSAS, cardiac complications, or neuromuscular disease; when sleep symptoms persist after T&A; and when neuromuscular or other systemic diseases are suspected. As summarized in Fig. 1, PSG is the gold standard for diagnosing and managing pediatric sleep disorders, particularly OSAS and related respiratory disturbances. It is essential for evaluating treatment efficacy, guiding interventions such as CPAP titration and T&A assessments, and optimizing ventilatory support in non-respiratory conditions like neuromuscular and chronic lung diseases.