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Eliot S Katz

Publications and source records attributed to Eliot S Katz.

11 recordsLinked to original sources

Pediatric adenoidectomy: what is the effect of obstructive symptoms on the likelihood of future surgery?

OBJECTIVE: Determine if pediatric patients undergoing adenoidectomy for obstruction have an increased likelihood of undergoing eventual tonsillectomy and/or second adenoidectomy over extended follow-up. METHODS: Retrospective cohort study within the ambulatory surgery component of a tertiary children's hospital. Exclusion criteria consisted of the presence of significant co-morbid conditions (obesity, craniofacial syndrome, cerebral palsy, etc.) and less than 1 year of post-adenoidectomy follow-up. The study population included 100 children (mean age=3.9 years, range 0.9-15 years) randomly selected from a financial billing database undergoing adenoidectomy either with pre-operative obstructive symptoms (OB n=52) or without pre-operative obstructive symptoms (NOB n=48) with a minimum of 1 year of retrospective follow-up. Electronic records were searched for subsequent surgery (tonsillectomy and/or revision adenoidectomy). RESULTS: Overall, 29 of 100 children (29%) underwent subsequent surgery (tonsillectomy and/or revision adenoidectomy) over an average of 3.46 years (range 1.0-6.59 years) retrospective follow-up. Children in the OB group were three times more likely (age, sex adjusted odds ratio=3.03, 95% confidence interval =1.18-7.78 p=0.021) than children in the NOB group to require tonsillectomy or second adenoidectomy. Age less than 2 years at time of initial adenoidectomy also suggested an increased likelihood of subsequent surgery. CONCLUSION: Children undergoing adenoidectomy with obstructive symptoms are more likely to require eventual tonsillectomy and/or second adenoidectomy than those undergoing adenoidectomy without obstruction. However, the low absolute likelihood of future surgery precludes a generalized recommendation for tonsillectomy in these children.

Adenoidectomy↗

Influence of airway pressure on genioglossus activity during sleep in normal children.

RATIONALE: Most children with obstructive sleep apnea are able to sustain stable breathing during portions of sleep, despite an anatomic predisposition toward airway collapse. This suggests that additional determinants of airway patency are active, such as neuromuscular compensation. OBJECTIVES/METHODS: Using a custom intraoral surface electrode to record pharyngeal dilator muscle activity (the genioglossus [EMGgg]), we evaluated the muscle, ventilatory, and arousal responses to negative-pressure challenges during sleep in 19 healthy control children. MEASUREMENTS AND MAIN RESULTS: In response to these challenges, we observed (1) marked variability in individual EMGgg responsiveness (peak EMGgg [mean+/-SD], 214+/-101% baseline), which was consistent within subjects; (2) a relationship between EMGgg activity and inspiratory flow and airway collapsibility; (3) reflex increases in flow (peak flow increase from challenge breaths 1-5 [mean+/-SD], 49+/-41% baseline) and respiratory rate often sufficient to sustain minute ventilation near baseline levels, without arousal; and (4) arousal threshold to be highest in stage 4, intermediate in stage 2, and lowest in REM sleep. CONCLUSIONS: Healthy children have wide variation in upper airway neuromuscular compensatory responses and arousal thresholds that could represent intermediate phenotypes affecting the expression of sleep apnea. Children with robust upper airway neuromuscular responsiveness, or a very high arousal threshold, may be able to sustain minute ventilation when challenged with negative airway pressure.

Adolescent↗

Upper airway dynamic responses in children with the obstructive sleep apnea syndrome.

Normal children have a smaller upper airway than adults, but, nevertheless, snore less and have less apnea. We have previously shown that normal children have an upper airway that is resistant to collapse during sleep. We hypothesized that this resistance to collapse is due to preservation of upper airway neuromotor responses during sleep. Furthermore, we hypothesized that upper airway responses would be diminished in children with the obstructive sleep apnea syndrome (OSAS). We therefore compared the upper airway pressure-flow relationship during sleep between children with OSAS and controls. Measurements were made by correlating maximal inspiratory airflow with the level of nasal pressure applied via a mask. Neuromotor upper airway activation was assessed by evaluating the upper airway response to 1) hypercapnia and 2) intermittent, acute negative pressure. We found that children with OSAS had no significant response to either hypercapnia or negative pressure during sleep, compared with the normal children. After treatment of OSAS by tonsillectomy and adenoidectomy, there was a trend for normalization of upper airway responses. We conclude that upper airway dynamic responses are decreased in children with OSAS but recover after treatment. We speculate that the pharyngeal airway neuromotor responses present in normal children are a compensatory response for a relatively narrow upper airway. Further, we speculate that this compensatory response is lacking in children with OSAS, most likely due to either habituation to chronic respiratory abnormalities during sleep or to mechanical damage to the upper airway.

Adenoidectomy↗

Ventilatory control and airway anatomy in obstructive sleep apnea.

Ventilatory instability may play an important role in the pathogenesis of obstructive sleep apnea. We hypothesized that the influence of ventilatory instability in this disorder would vary depending on the underlying collapsibility of the upper airway. To test this hypothesis, we correlated loop gain with apnea-hypopnea index during supine, nonrapid eye movement sleep in three groups of patients with obstructive sleep apnea based on pharyngeal closing pressure: negative pressure group (pharyngeal closing pressure less than -1 cm H(2)O), atmospheric pressure group (between -1 and +1 cm H(2)O), and positive pressure group (greater than +1 cm H(2)O). Loop gain was measured by sequentially increasing proportional assist ventilation until periodic breathing developed, which occurred in 24 of 25 subjects. Mean loop gain for all three groups was 0.37 +/- 0.11. A significant correlation was found between loop gain and apnea-hypopnea index in the atmospheric group only (r = 0.88, p = 0.0016). We conclude that loop gain has a substantial impact on apnea severity in certain patients with sleep apnea, particularly those with a pharyngeal closing pressure near atmospheric.

Adult↗

Genioglossus activity during sleep in normal control subjects and children with obstructive sleep apnea.

Children with obstructive sleep apnea syndrome (OSAS) have more collapsible airways compared with normal subjects, yet sustain stable breathing during wakefulness and part of sleep. This indicates successful neuromuscular compensation. Using a custom intraoral surface electrode to record pharyngeal dilator muscle activity (the genioglossus [EMGgg] normalized to the wakeful baseline), we performed overnight polysomnograms in three groups of children: (1) patients with OSAS without continuous positive airway pressure (CPAP) (n = 13); (2) patients with OSAS with CPAP (n = 5); and (3) control subjects without CPAP (n = 13). Our objective was to evaluate the EMGgg as a function of sleep state and during disordered breathing, compared with stable sleep and wakefulness. In control subjects, the EMGgg decreased from wakefulness to Stage 2 (mean +/- SD, 65 +/- 6%), and further during REM (51 +/- 9%) (p < 0.05). In patients with OSAS, the EMGgg for apneic breaths during REM (37 +/- 9%) was lower than during stable breathing (83 +/- 17%) (p < 0.05) and wakefulness (p < 0.05). CPAP lowered the EMGgg in patients with OSAS during all sleep states. These data indicate that (1) EMGgg compensatory mechanisms remain active during sleep in patients with severe OSAS; (2) EMGgg reductions are temporally associated with sleep apnea events; and (3) REM sleep is associated with the lowest and most variable EMGgg.

Adolescent↗

Developmental changes in upper airway dynamics.

Normal children have a less collapsible upper airway in response to subatmospheric pressure administration (P(NEG)) during sleep than normal adults do, and this upper airway response appears to be modulated by the central ventilatory drive. Children have a greater ventilatory drive than adults. We, therefore, hypothesized that children have increased neuromotor activation of their pharyngeal airway during sleep compared with adults. As infants have few obstructive apneas during sleep, we hypothesized that infants would have an upper airway that was resistant to collapse. We, therefore, compared the upper airway pressure-flow (V) relationship during sleep between normal infants, prepubertal children, and adults. We evaluated the upper airway response to 1). intermittent, acute P(NEG) (infants, children, and adults), and 2). hypercapnia (children and adults). We found that adults had a more collapsible upper airway during sleep than either infants or children. The children exhibited a vigorous response to both P(NEG) and hypercapnia during sleep (P < 0.01), whereas adults had no significant change. Infants had an airway that was resistant to collapse and showed a very rapid response to P(NEG). We conclude that the upper airway is resistant to collapse during sleep in infants and children. Normal children have preservation of upper airway responses to P(NEG) and hypercapnia during sleep, whereas responses are diminished in adults. Infants appear to have a different pattern of upper airway activation than older children. We speculate that the pharyngeal airway responses present in normal children are a compensatory response for a relatively narrow upper airway.

Adolescent↗

Can history and physical examination reliably diagnose pediatric obstructive sleep apnea/hypopnea syndrome? A systematic review of the literature.

OBJECTIVE: Using an evidence-based technique, systematically review the literature to evaluate the accuracy of routine clinical history and physical examination in the diagnosis of obstructive sleep apnea/hypopnea syndrome (OSAHS) in the pediatric patient. STUDY DESIGN AND SETTING: The biomedical literature was systematically reviewed. Articles comparing the results of clinical evaluation to polysomnography (PSG) were selected. The level of evidence was assessed using established evidence-based medicine (EBM) guidelines. RESULTS: Twelve articles were identified using the search criteria. Eleven of 12 articles concluded that clinical evaluation is inaccurate in the diagnosis of OSAHS. The level of evidence was good to very good (Grade B/B+). CONCLUSION/SIGNIFICANCE: Clinical history and physical examination are not reliable for diagnosing OSAHS compared with overnight PSG. Complicating the interpretation of this work is the lack of a validated PSG threshold of clinically significant disease. There is an urgent need for the development of adequate screening tests with validated clinical outcomes. EBM RATING: B-3.

Adolescent↗

Genioglossus activity in children with obstructive sleep apnea during wakefulness and sleep onset.

A prominent role for upper airway neuromuscular control mechanisms in the pathophysiology of pediatric obstructive sleep apnea syndrome (OSAS) is suggested by the observation that obstruction does not occur during wakefulness and is infrequently seen during non-REM sleep. Using a custom intraoral surface electrode to record genioglossal activity (genioglossal electromyography [EMGgg]), normalized with a maximal maneuver, we studied 10 children with OSAS and 6 normal control subjects to determine EMGgg activity during (1) wakefulness, (2) the sleep onset period, and (3) stable non-REM sleep. We observed that the EMGgg activity in patients with OSAS compared with control subjects was significantly greater during wakefulness (3.6 +/- 1.8 vs. 1.6 +/- 1.8% maximum, p < 0.05) and had a greater decline during the early and late sleep onset period (p < 0.05). During stable non-REM sleep, EMGgg remained below the wakeful baseline in all normal control subjects but increased above the baseline in four of the patients with OSAS. We speculate that the increased EMGgg activity during wakefulness represents a reflex-driven neuromuscular compensation for an anatomically compromised airway. Furthermore, the larger decline in EMGgg at sleep onset observed in patients with OSAS is consistent with the relative loss of this reflex. Finally, the return of EMGgg activity above baseline in patients with severe OSAS suggests that some chemical or mechanical compensatory mechanisms remain active during stable non-REM sleep in children.

Adolescent↗

Pulse transit time as a measure of arousal and respiratory effort in children with sleep-disordered breathing.

The upper airway resistance syndrome (UARS) is associated with neurobehavioral morbidity in children. The diagnostic gold standard for UARS is esophageal manometry. However, this is invasive. Furthermore, upper airway obstructive events in sleeping children frequently terminate without visible electrocortical (EEG) arousal. The pulse transit time (PTT) is a noninvasive marker of blood pressure and, therefore, subcortical arousal. Blood pressure elevation, associated with respiratory arousal from sleep, results in a drop in the PTT. We hypothesized that: 1) the PTT is a more sensitive measure of respiratory arousal than EEG; and 2) the PTT arousal index can distinguish children with UARS from those with primary snoring. Polysomnography, including esophageal manometry and PTT, was measured prospectively in 24 symptomatic children and 10 normal controls. Apnea, hypopnea, and respiratory effort-related arousal events terminated in a PTT arousal 91%, 83%, and 80% of the time, and in an EEG arousal in 55%, 51%, and 43% (all p < 0.05), respectively. The PTT arousal index was significantly greater in children with UARS (6.8 events/h) than primary snoring (2.2 events/h) (p < 0.05). We conclude that, in children, PTT arousals are a more sensitive measure of obstructive events than visible EEG arousals.

Adult↗

Night-to-night variability of polysomnography in children with suspected obstructive sleep apnea.

OBJECTIVES: To determine whether a single polysomnographic night was a valid measure of obstructive sleep apnea syndrome (OSAS) in children with symptoms of sleep-disordered breathing. STUDY DESIGN: The night-to-night variability of respiratory and sleep parameters was measured prospectively in 30 snoring children aged 1.6 to 11.3 years (mean +/- SD, 4.1 +/- 2) by using 2 nocturnal polysomnograms performed 7 to 27 days apart (14 +/- 5 days). RESULTS: The mean of the respiratory variables including apnea index, apnea/hypopnea index, arterial oxygen saturation, and end-tidal partial pressure of carbon dioxide were not significantly different from night to night. Among the sleep parameters, there was no significant night-to-night difference in sleep efficiency, arousal index, percent rapid eye movement, or percent of slow wave sleep. Only the percentage of stage 2 was significantly different between the nights. The polysomnographic clinical diagnosis remained the same on both nights for all children, although the disease severity differed slightly in 2 patients. CONCLUSIONS: There is little clinically significant night-to-night variability in pediatric polysomnography, and no first-night effect. These data suggest that a single polysomnographic night is an adequate measure of the OSAS in children with symptoms of sleep-disordered breathing.

Child↗