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Background: Among autonomic seizures apnea still represent a challenge for physicians, and it might constitute the only isolated sign of neurological disorder. The aim of this review is to describe ictal apnea (IA) and its treatment options., Methods: MeSH and keywords were combined: "neonatal seizures", "ictal neonatal apnea", "apneic seizures". All identified papers were screened for neonatal seizures titles and abstracts; case reports describing patients with IA as an isolated manifestation of neonatal seizures were included., Results: Eight studies including a total of 13 patients were identified. Among 13 patients, 9 were full-term and 4 were preterm neonates. All patients developed IA within twenty-one days from birth. Etiologies of seizures included: temporal lobe hemorrhage (3 pt), occipital stroke (1 pt), hypoxic-ischemic encephalopathy (HIE) (1 pt), parasagittal injury (1 pt), 18 trisomy (2 pt). Five patients showed no structural CNS alterations. Ten patients had the ictal focus localized in the temporal lobe; the occipital lobe was the second most involved site. Phenobarbital was administered in 76 % of cases with IA (10 pt), and showed efficacy in 74 % of them; 2 required a second anti-epileptic drug (AED) to reach seizure control. Levetiracetam was given to 11 % (2 pt) successfully. Only one was treated with midazolam and one did not require any anticonvulsant., Conclusions: Not homogeneous data and paucity of isolated IA currently reported in literature limits agreement about definition, management and treatment of entity, however an ever-growing attention is needed, and EEG/aEEG, despite their possible controversies in the diagnosis, should be performed to investigate unexplained forms of apnea., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: During induction of general anaesthesia, patients frequently experience apnoea, which can lead to dangerous hypoxaemia. An obstructed upper airway can impede attempts to provide ventilation. Although unrelieved apnoea is rare, it continues to cause deaths. Clinical investigation of management strategies for such scenarios is effectively impossible because of ethical and practical considerations., Methods: A population-representative cohort of 100 virtual (in silico) subjects was configured using a high-fidelity computational model of the pulmonary and cardiovascular systems. Each subject breathed 100% oxygen for 3 min and then became apnoeic, with an obstructed upper airway, during induction of general anaesthesia. Apnoea continued throughout the protocol. When arterial oxygen saturation (Sao 2 ) reached 20%, 40%, or 60%, airway obstruction was relieved. We examined the effect of varying supraglottic oxygen fraction (Fo 2 ) on the degree of passive re-oxygenation occurring without tidal ventilation., Results: Relief of airway obstruction during apnoea produced a single, passive inhalation (caused by intrathoracic hypobaric pressure) in all cases. The degree of re-oxygenation after airway opening was markedly influenced by the supraglottic Fo 2 , with a supraglottic Fo 2 of 100% providing significant and sustained re-oxygenation (post-rescue Pao 2 42.3 [4.4] kPa, when the airway rescue occurred after desaturation to Sao 2 60%)., Conclusions: Supraglottic oxygen supplementation before relieving upper airway obstruction improves the effectiveness of simulated airway rescue. Management strategies should be implemented to assure a substantially increased pharyngeal Fo 2 during difficult airway management., (Copyright © 2020 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Child abuse was suspected in a case of out-of-hospital arrest with minor brain injuries. Confronted with continued disputes on pathophysiologic correlates even after autopsy, to assist the differentiation of potential causes of sudden cardiopulmonary arrest in children, we tried to identify the mechanism of cardiopulmonary arrest in brain injuries from different causes. Systematic review was carried out in two stages. First, major external causes of cardiopulmonary arrest among children and infants were identified from Pubmed and Google Scholar search, and then the exact sequence of cardiopulmonary arrest, and their pathophysiologic features were identified based on articles of animal models of brain injury. From the review, we have identified four major groups of external circumstances for rather sudden cardiopulmonary arrest from brain damage in children, after excluding congenital and other unrelated diseases; 1) impact brain apnea, 2) anoxic insults, 3) drug or other substance induced central nervous system depression, and 4) traumatic brain damage. Each group has different features in the course of cardiac and respiratory arrests. Based on this review of pathophysiologic features of cardio-respiratory responses from external causes, we have presented a suspected, but unlikely, child abuse case of respiratory arrest from brain injury. The social consequences of both unknowingly missing, and falsely incriminating the abuse can be grave, and the identification of the mechanisms of cardiopulmonary arrest from brain injury can be important for the differentiation of various potential causes., (Copyright © 2020 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Pseudocholinesterase deficiency is a rare genetic as well as an acquired disorder that affects the body's ability to metabolize choline esters such as succinylcholine and mivacurium. It can be inherited as an autosomal recessive trait, occurring in approximately 1 in 3,200 to 1 in 5,000 people. In most cases of pseudocholinesterase deficiency, no signs or symptoms of the condition exist. It is first suspected after a prolonged recovery from paralysis following general anesthesia in which succinylcholine or mivacurium are administered. We emphasize the importance of obtaining a detailed history prior to any endoscopic intervention or surgery requiring monitored anesthesia care or general anesthesia. In addition, a family history of anesthesia complications may help identify patients at risk. This article examines a case of a patient who underwent a successful endoscopic pneumatic dilation under general anesthesia for the treatment of achalasia, but was subsequently admitted to the intensive care unit, requiring mechanical ventilator support, for 18 hours. The patient made a complete recovery and was discharged home with no further complications. This case stimulated a review of this entity and we provide recommendations relevant to all proceduralist and anesthesia staff, as well as all personnel involved in procedures., (Copyright © 2018. Published by Elsevier Inc.)

Background.: Mask ventilation and tracheal intubation are basic techniques for airway management and mutually inclusive rescue measures to restore ventilation. The aim of this study was to compare the effectiveness of mask ventilation between two commonly used techniques of two-handed mask ventilation in obese unconscious apnoeic adults., Methods.: Eighty-one obese adults received mask ventilation after induction using C-E clamp and modified V-E clamp techniques in a randomized crossover manner. Mechanical ventilation was provided using a pressure-control mode, at a rate of 10 bpm, with an inspiratory-to-expiratory time ratio of 1:2 and a pre-set plateau airway pressure of 20 cm H 2 O. The primary outcome was expired tidal volume., Results.: The BMI for the subjects was 37 ( sd 4.9) kg m -2 . The failure rates for mask ventilation (tidal volume≤anatomical dead space) were 44% for the C-E technique and 0% for the V-E technique ( P <0.001). Tidal volume was significantly lower for the C-E than the V-E technique [371 ( sd 345) vs 720 (244) ml, P <0.001]. The peak airway pressures were 21 ( sd 1.5) cm H 2 O for the C-E technique and 21 (1.3) cm H 2 O for the V-E technique., Conclusions.: Mask ventilation using the modified V-E technique is more effective than with the C-E technique in unconscious obese apnoeic adults. Subjects who fail ventilation with the C-E technique can be ventilated effectively with the V-E technique., Clinical Trial Registration.: NCT02580526., (© The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

Succinylcholine is a neuromuscular block whose duration of action depends on rapid hydrolysis by butyrylcholinesterase (BChE). In patients with common BChE activities, succinylcholine duration of action is short (10min). BChE deficiency induces a slower hydrolysis of the drug and consequently prolonged neuromuscular block, leading to apnea. We report a case of prolonged neuromuscular block after administration of succinylcholine in a 14-year-old boy. Biological investigations revealed a marked BChE deficiency (1099U/L) related to the presence of three point mutations in the BCHE gene in a compound heterozygous state: p.Asp70Gly (rs1799807), p.Ala539Tyr (rs1803274), and p.Phe118Valfs*12 (rs398124632). The diagnosis of genetic BChE deficiency (OMIM 177400) was retained. This case is intended to present the pathophysiology of genetic BChE deficiency, its management, and the diagnostic strategy to be implemented., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Apnea of prematurity and gastroesophageal reflux (GER) are both common occurrences in preterm infants and widely perceived to be causally related. We seek in this review to provide a potential guideline for neonatal GER non-pharmacologic and pharmacologic therapy. Available physiologic data suggest that when there is a temporal relationship apnea may be more likely to predispose to GER via esophageal sphincter relaxation than vice versa. Measurement of multiple intraluminal impedance via esophageal catheter in addition to esophageal pH has enhanced our understanding of GER, although it also did not demonstrate a causal relationship between apnea and GER. The incidence of GER may be modified by thickening feeds and position change without adverse effects. In contrast, pharmacotherapy including acid suppression therapy may have adverse effects and should only be used in infants with clear evidence of clinical benefit., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Apnoea of prematurity (AOP) frequently recurs in preterm infants. We have previously shown that a significant but variable proportion of AOP is induced by gastro-oesophageal reflux (GOR)., Aim: The aim of this study is to evaluate the efficacy of sodium alginate in reducing the frequency of GOR-related AOP., Subjects: Twenty-eight preterm infants with AOP were studied by a six-hour recording of combined multichannel intraluminal impedance and pH monitoring and polysomnography, including two three-hour postprandial periods: sodium alginate was given after one single meal named as drug-given (DG) meal, while the other as drug-free (DF)., Results: During 165h of registration, 715 apnoeas were recorded, 368 after-DG and 347 after-DF (p=.99); furthermore, 851 GOR episodes were detected, 315 after-DG and 536 after-DF (p=.001). No differences in the number of AOP were found between DG and DF. A significant reduction in the number of acid GORs and in acid exposure was found during DG, while the administration of sodium alginate didn't influence non-acid GOR indexes. The frequency of GOR-related apnoeas didn't differ between DG and DF., Discussion: Sodium alginate doesn't reduce the total number of AOP nor GOR-related apnoeas. On the other hand, it reduces acid GOR features, while it had no effect on non-acid GOR indexes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the association between the frequency of acid reflux (AR) and weakly acid reflux (WAR) and specific respiratory symptoms (RS) in childhood., Study Design: We retrospectively reviewed medical records of children with difficult-to-treat RS, not under acid suppressive therapy, and with a positive multiple intraluminal esophageal impedance (pH/MII) monitoring. To discriminate children with prevalent AR and WAR events, a ROC curve was designed and the distribution of the different RS in children with prevalent AR or WAR events was analyzed., Results: A higher number of AR over WAR events was detected (p < 0.0001) but the WAR-to-AR events ratio progressively decreased with the age of the subjects (p < 0.01). Similar total number of reflux events was found in the three age group and in children with a more prevalent WAR or AR. The most prevalent RS, equally distributed among the three age groups, were persistent and/or nocturnal cough, wheezy bronchitis/asthma, and recurrent lower respiratory tract infections (RLRTI). Apnoea was most frequent in infants (p = 0.036). A higher frequency of RLRTI, but not of nocturnal cough or wheezy bronchitis/asthma, was shown in WAR as compared with AR patients (p = 0.040), and specifically those in the school-aged group (p = 0.013). Age and WAR were respectively identified as independent predictors of apnoea and RLRTI (p < 0.05)., Conclusion: WAR events are common in children with gastroesophageal reflux and difficult-to-treat RS and often associated with RLRTI. These findings support the role of pH/MII monitoring in the evaluation of these patients and may explain the disappointing clinical results often observed with anti-acid treatments., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

We report a girl with severe manifestations of Townes-Brocks syndrome (TBS) and a previously unreported serious congenital dysphagia. She is unable to swallow her saliva and consequently chokes frequently with desaturations still existing beyond the second year of life. Involvement of the feet was more extensive than is usually seen in TBS. Mutation analysis of the SALL1 gene, responsible for TBS, resulted in the identification of the de novo hot-spot mutation p.Arg276X. This report adds another rare, but serious manifestation to the multiorgan involvement found in TBS.

The authors report a case of an infant girl with macrocephaly-cutis marmorata telangiectatica congenita (Macrocephaly-CMTC). This patient presented with developmental delay, mild subcostal retractions, and occasional apneic spells. An MRI demonstrated mild to moderate lateral ventricle hydrocephalus, left hemi-megalencephaly, and left cerebellar tonsillar herniation with full occlusion of the cisterna magna. Her foramen magnum was narrowed, measuring 17.5mm in transverse diameter. This value was significantly below the 50th percentile for age, which is 23.5mm. Together, these findings were suggestive of cervicomedullary cord compression, concerning for sudden death. The patient underwent posterior fossa decompression by suboccipital craniectomy and cervical laminectomy. Initially due to hypertrophy and paralysis of the left true and false vocal cords, endotracheal intubation was not achieved, requiring tracheostomy tube placement. To our knowledge this is the first report of apnea in a patient diagnosed with M-CMTC, likely due to cervicomedullary cord compression and perhaps exacerbated by unilateral laryngeal hypertrophy. M-CMTC is a newly-described hemi-hypertrophy syndrome affecting the neurodevelopment of affected children. The authors emphasize airway obstruction secondary to unilateral hypertrophy of the vocal cords in addition to brainstem compromise as a consideration for the etiology of apnea in M-CMTC patients presenting with signs and symptoms of cervicomedullary cord compression.

Aim: Analyse heart rate variability (HRV) of preterm neonates undergoing a polysomnography in relation to the occurrence of abnormal cardiorespiratory events on one hand and the type of sleep states on the other hand., Methods: To quantify nonlinear HRV, the numerical noise titration technique is used, adapted to neonatal heart rate data. HRV is calculated for 30 preterm neonates with mean post-conceptional age of 36.4weeks, divided into three groups according to the occurrence of abnormal events during the polysomnographies and the eventual home monitoring., Results: Periods of non-REM sleep have lower noise limit values and can be distinguished significantly from periods of REM sleep and from the total recording period. The presence of abnormal events does not influence this finding. Significant differences between groups are only found during non-REM segments by means of the noise limit value computed via numerical noise titration while the linear HRV parameters were not able to discriminate., Conclusion: ECG measurement of a relatively short non-REM sleep period without specific abnormal events is sufficient to define a mature cardiorespiratory pattern in preterm infants.

Objectives: The aim was to investigate the significance of snoring and sleep apnea on daytime symptoms in a population-based sample of women., Method: From the general population, 400 women aged 20 to 70 years were randomly selected, with oversampling of habitually snoring women. The women were investigated using full-night polysomnography and a questionnaire. The apnea-hypopnea index (AHI) was calculated, and women who acknowledged snoring loudly and disturbingly often or very often were considered habitual snorers., Results: Habitual snoring was independently related to excessive daytime sleepiness (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.31 to 3.99), to falling asleep involuntarily during the day (OR, 2.11; 95% CI, 1.06 to 4.21), to waking up unrefreshed (OR, 2.14; 95% CI, 1.30 to 3.52), to daytime fatigue (OR, 2.77; 95% CI, 1.54 to 4.99), and to a dry mouth on awakening (OR, 2.00; 95% CI, 1.22 to 3.27) after adjustment for AHI, age, body mass index (BMI), smoking, total sleep time, percentage of slow-wave sleep, and percentage of rapid eye movement (REM) sleep. An AHI > or = 15/h was only related to a dry mouth on awakening after adjustment for snoring, age, BMI, smoking, total sleep time, percentage of slow-wave sleep, and percentage of REM sleep (OR, 2.24; 95% CI, 1.14 to 4.40). An AHI of 5 to 15/h was not related to any daytime symptom., Conclusions: Excessive daytime sleepiness and daytime fatigue are related to habitual snoring independent of the apnea-hypopnea frequency, age, obesity, smoking, and sleep parameters in a population-based sample of women, but not to the AHI. This indicates that snoring is an independent cause of excess daytime sleepiness and not merely a proxy for sleep apnea.

Introduction: Apnea of prematurity develop during the first days of life and usually resolve by the time the infant reaches 36-37 weeks postmenstrual age. In a few cases, they persist beyond term, especially in infants delivered at the youngest gestational ages (24-28 GA), and require specific care. In our unit, those preterm babies are discharged home with caffeine citrate treatment. Discontinuing the treatment is performed in hospital when they achieve a postmenstrual age of at least 42 weeks., Objective: To identify predictive factors of persistent apnea in preterm babies., Material and Methods: Retrospective study comparing a population of 41 preterm infants discharged with treatment to 123 preterm babies discharged without treatment to identify predictors of persistent apnea., Results: Factors significantly associated were: birth weight<1500 g, initial hypotension, gastroesophageal reflux, need for continuous positive airway pressure and multiparity. At home, no infant died and no adverse effect was reported by parents., Conclusion: Persistent apnea can be responsible for prolonged hospitalization. Risk factors can be identified in some children. Discharging with treatment can be an alternative to their hospitalization.

Background: Hypoxaemia during apnoea develops earlier and progresses faster in children than in adults. Ethical and practical considerations prevent detailed investigation of the issue., Methods: We used the Nottingham Physiology Simulator, an integrated, computational model of the respiratory and cardiovascular systems, to model four healthy virtual children (ages: 1 month, 1, 8 and 18 yr) and exposed them to apnoea after a variety of preoxygenation periods (0, 1 and 3 min) and with open and obstructed airways during apnoea., Results: The rate of oxygen desaturation of haemoglobin from 90 to 40% was similar across the ages studied, being approximately 30% min(-1). The greatest difference between ages was found in the speed of early desaturation (i.e. between the onset of apnoea and the acceleration of haemoglobin desaturation); in the absence of preoxygenation and with an open airway, this time was 6.6 s in the 1-month-old and 33.6 s in the 8-yr-old., Conclusions: Preoxygenation had a substantial effect on the speed of early desaturation, but less effect on the time for SaO2 to decrease from 90 to 40%. Preoxygenation substantially delayed dangerous desaturation in all age groups, although the rapidity of denitrogenation in the very young (caused by the large ratio of minute ventilation to functional residual capacity) resulted in lengthy preoxygenation having little benefit over brief preoxygenation. Airway obstruction during apnoea accelerated every child's hypoxaemia through prevention of mass flow addition to oxygen stores and through intrathoracic depressurization. On average, haemoglobin desaturation from SaO2 90 to 40% was 33% min(-1) with an obstructed airway and 26% min(-1) with an open airway; all ages were similarly susceptible to this effect.

Objective: The study was undertaken to determine whether respiratory distress syndrome (RDS) is associated with an increased risk of nonpulmonary morbidity in neonates born between 34 to 36 weeks' gestation., Study Design: We performed a matched case-control study of 75 infants with (cases) and 75 without (controls) RDS, delivered between 34 and 36 weeks' gestation. Infants with RDS and no other causes for respiratory failure (anomalies, hydrops, asphyxia) were included. Controls were matched for gestational age at birth, year of care, gender, plurality, and race. Inpatient records were reviewed for the incidence of nonpulmonary morbidities before discharge. McNemar test and conditional logistic regression were used to evaluate differences between cases and controls., Results: Our study cohort was 69% male, 48% white, 33% African American, and 19% Hispanic. Cases had longer hospital (11 vs 7days) and neonatal intensive care unit stays (10 vs 7 days), and more frequent apnea-bradycardia (30% vs 5%), pneumonia (12% vs 1%), and suspected sepsis diagnoses (27% vs 3%), P

Unlabelled: We conducted a case control study during six and a half years with the objective to analyse the risk factors for NEC., Population and Methods: All cases of confirmed NEC matched to controls for identical gestational age and period of hospitalization; apnoeas-bradycardias prospectively counted., Results: Forty-five cases were compared to 89 controls. The isolated risk factors were: an intra-uterine growth retardation (OR = 3,65, 95% confidence interval [CI] 95%: 1,54-8,63); a birth weight < 1000 g (OR = 8,16, CI 95%: 1,17-56,62), compared to a weight >/= 1500 g; a triple antibiotherapy (OR = 6,15, CI 95%: 1,16-32,45); an umbilical venous catheterization (OR = 2,64, CI 95%: 1,09-6,44); a number of simple apnoeas-bradycardias >/= 3rd tercile (n = 27) (OR = 4,54, CI 95%: 1,29-15,93), or severe (stimulated or with hypoxia) apnoeas-bradycardias >/= 3rd tercile (n = 8) (OR = 6,15, CI 95%: 1,59-23,75); an haemoglobin level lower than the 1(st) tercile (95 g/L) (OR = 5,90, CI 95%: 1,20-20,13); and milk thickening by Gumilk (OR = 2,78, CI 95%: 1,11-6,90)., Conclusion: In the present practices, anoxo-ischemic factors during the first week of life do not represent an important risk of NEC; a great vigilance must be exercised for indications of the triple antibiotherapy and the treatment of apnoeas-bradycardias.

Incidence and severity of apnea and bradycardia in preterm infants may be related to the immaturity of the respiratory control mechanisms. In addition, there is a steadily increasing risk for sudden death with decreasing birth weight or gestational age during the first year of age, justifying the search for a specific preventing strategy for very low birth weight (VLBW) infants. The purpose of this paper is to define practical preventive guidelines for VLBW infants at the time of discharge from the neonatal intensive care units. Polysomnography appears as a useful method to detect those among the VLBW infants who are at risk of life threatening events and may need home monitoring.

Objective: To determine how mental retardation at age seven is related to certain maternal, perinatal, and neonatal characteristics., Method: A sample of 35,704 children followed from the prenatal period to age 7 years in the Collaborative Perinatal Project provided data on nine maternal and pregnancy characteristics and 12 neonatal factors., Results: Low socioeconomic status of the family (SES) accounted for 44-50% of mental retardation and a low level of maternal education accounted for 20%. Other prenatal factors with significantly elevated relative risks, (P < 0.05) were maternal IQ score less than 70, weight gain in pregnancy less than 10 pounds and multiple birth. Maternal anemia in pregnancy accounted for 14% of mental retardation in blacks, and, urinary tract infections accounted for 6% of mental retardation in whites. Significant elevations in relative risk were found for major genetic and post-infection syndromes, CNS malformations, cerebral palsy, seizures, abnormal movements or tone, and low birth weight. Relative risk was also significantly increased with low 1 minute APGAR, primary apnea, and head circumference and length more than 2 SD below average but only in the low SES black subgroup., Conclusion: Early developmental events can be ranked on the basis of the strength of their association with mental retardation and such rankings can be used as a guide for defining risk status in early infancy.

Methylxanthine use in the treatment of apnea of prematurity is well documented. This drug is avoided in patients with aberrant pathways of conduction such as Wolff-Parkinson-White syndrome. In theory, methylxanthines enhance precipitation and exacerbation of tachyarrhythmias to which these patients are predisposed. This article reports a case of Wolff-Parkinson-White syndrome in a preterm neonate with severe apneic episodes in which methylxanthines were used. However, no adverse effects on cardiac rate or rhythm were encountered.

Obstructive sleep apnea syndrome (OSAS) and heavy snoring during sleep, without sleep apnea, has been well described in children and adults. We report a case series of 25 full-term infants, prospectively obtained from a database of nearly 700 "apparent life-threatening event" (ALTE) cases, who presented between 3 weeks and 4 1/2 months of age an ALTE and who progressively developed more florid symptomatology and polygraphic findings. All of them were classified as OSAS patients by five years of age. These index cases are compared with two other ALTE infant groups followed in parallel during the first year of life but whose symptoms were short-lived. The index cases presented more frequently a positive family history of OSAS and an early report of snoring or noisy breathing during sleep. Usage of an esophageal balloon to monitor esophageal pressure (Pes) and usage of nasal continuous positive airway pressure (CPAP) as a test may help in the early recognition of these infants, who appear to make more effort to breathe during sleep, based on the indirect evidence of Pes measurements. It is suggested that anatomic features, including a small posterior airway space leading to an abnormal degree of upper airway resistance, may be the cause of the symptoms presented by these infants. Considering the parental anxiety generated by persistence of symptoms after the first year of life in ALTE infants, recognition of this subgroup is important.

The characteristics of the arterial oxygen saturation (SaO2) signal during episodes of hypoxaemia (SaO2 less than or equal to 80% for greater than or equal to 4 s) associated with periodic and non-periodic apnoeic pauses were studied in 16 preterm infants with cyanotic episodes (patients). and 15 asymptomatic preterm infants (controls), matched on birthweight and gestational age. The patients showed a significantly higher percentage of apnoeic pauses followed by a hypoxaemic episode (25 vs. 6%, P less than 0.01), and a two-fold increase in the slope of the desaturation curve (8.4 vs. 4.3% per s, P less than 0.005) in periodic compared with non-periodic breathing. All other characteristic of oxygenation (baseline SaO2 before episodes of hypoxaemia, delay between onset of apnoeic pause and onset of desaturation, lowest SaO2 during episodes of hypoxaemia) were similar for periodic and non-periodic breathing patterns. Similar, but not significant, differences between isolated and periodic apnoeic pauses were also present in the controls. An analysis of episodes of bradycardia (less than or equal to 100 beats per minute (bpm] showed that out of 121 episodes in the patients 118 were accompanied by a fall in SaO2 to less than or equal to 80%, and in the remaining three SaO2 fell to 82%, 85% and 86%, respectively. Thus all episodes of bradycardia (less than or equal to 100 bpm) were associated with a fall in SaO2 detected by beat-to-beat pulse oximetry. Examination of hypoxaemic episodes and their relationship with bradycardia and with apnoeic pauses, periodic and non-periodic, may help the further understanding of the control of arterial oxygenation in preterm infants with cyanotic episodes.

To examine the possible relationship between systemic HT and SAS we compared 21 hypertensive (HT+) and 29 normotensive (HT-) patients for morphologic characteristics, sleep disturbances and respiratory events monitored during a full night polysomnography. There was no significant difference between HT+ and HT- patients with respect to age, weight, BMI, sleep stage distribution and disorganization, apnea-hypopnea index (number of episodes per hour of sleep) and duration (minutes per hour of sleep) nor O2 saturation indices: mean nocturnal and minimum O2 saturation. We conclude therefore that HT in SAS patients is not directly related to morphologic characteristics, sleep disturbances and breathing abnormalities.

Thirty infants of less than 31 weeks post-menstrual age were monitored for apnoea using routine medical equipment and intermittent 24-h pneumocardiograms. These infants were examined again between 16 and 36 months of age. Full physical and ophthalmological examinations were carried out as well as audiometry and assessment using the Griffiths mental developmental scales. Twenty-five of these infants had suffered apnoeic attacks and two of these infants had an abnormal developmental quotient. Neither sensorineural deafness of retinopathy of prematurity were detected in the children who suffered apnoeic episodes. The poor prognosis which has been associated with neonatal apnoea may not apply to those infants without other serious neonatal problem.

Patients with daytime sleepiness present altered states of consciousness. The occurrence of these states impairs their professional, social and familial activities and may threaten life itself. The automatic behavior syndrome is characterized by continuation of mechanical activity and complete amnesia. Episodes lasting from a few seconds to several hours are correlated with repetitive micro-sleep periods. During cataplectic attacks, patients may have a meshing of reality with hallucinatory dream contents. Sleep-induced apnea may lead to abnormal movement and abnormal ambulation during sleep as well as hallucinations in the early morning. These altered states of consciousness must be considered as diagnostic indexes in differentiating epileptic syndromes from syndromes of daytime sleepiness.

Ten infants with rapidly developing and severe episodes of hypoxaemia (15-120 s duration) were studied. In infants over 2 months old most episodes occurred when awake, after a sudden noxious stimulus. In younger infants frequent yet undetected episodes occurred during sleep and feeding. Arterial PO2 fell below 20 mm Hg within 20 s, and loss of consciousness, sometimes with convulsions, occurred after 30 s. Clinical observations, measurements of respiratory movements, air flow, oesophageal pressure, external oblique surface electromyogram, and, in two cases, chest fluoroscopy and microlaryngoscopy documented episodes of no inspiratory flow but continued expiratory activity at low lung volume with partial or complete glottic closure. In five infants, episodes continued despite tracheostomy or an indwelling nasotracheal tube. No intracardiac shunt could be demonstrated and the rapid fall in arterial PO2 was attributed to lack of ventilation at a maximum expiratory position in the presence of a rapid recirculation time. In five infants tested there was a low proportion of phosphatidylcholine in the tracheal aspirate. In one infant audible expiratory braking (grunting) was present for most of the awake time. This previously unrecognised mechanism for severe hypoxaemia may be one cause of neurodevelopmental damage and sudden death in infants and young children.

Abnormal respiration with episodic tachypnea-apnea can occur in several syndromes (particularly, the Rett, Joubert, Mohr and Dandy-Walker syndromes). These syndromes are briefly reviewed. In the Rett syndrome, in contrast to in most other genetically determined syndromes, the onset of breathing abnormalities does not occur in the neonatal period.

Normal subjects may present central-type apneas or periodic respiration during sleep (stages I and II and paradoxical sleep). The importance of these respiratory disorders increases with age. Hypersomniac patients can manifest either similar or more significant sleep respiratory disorders than normal subjects. The presence of cataplexy or obesity does not permit the prediction of the existence of respiratory arrhythmias or of their type. Sleep respiratory arrhythmias of central type are not likely to cause hypersomnia; however, an aggravating role may be played by obstructive apneas.

Fourteen morbidly obese subjects, referred to our institution for bypass surgery for obesity, were studied with regard to pulmonary function and respiratory patterns during sleep. The seven female patients experienced no episodes of desaturation or disordered breathing during sleep. Six of the seven male patients experienced desaturation or disordered breathing. The one who did not had hypogonadism, suggesting that testosterone may have a role in the regulation of breathing during sleep. The two patients with the most frequent episodes of apnea and lowest oxygen saturation had a clinical picture consistent with the pickwickian syndrome. This supports the relationship previously noted between the degree of hypoxia and the presence of hypersomnolence.

Sleep, respiratory, and cardiac data obtained during sleep and wakefulness by continuous 24-hour polygraphic monitoring from twelve infants who were "near misses" for the sudden-infant-death syndrome were compared with similar information obtained from seven low-risk infants. Although the sleep variables studied were of limited value in differentiating between the low and high risk patients, respiratory and cardiac abnormalities were strikingly more common in near-miss infants. High-risk infants demonstrated both obstructive and mixed stopped-breathing episodes (S.B.E.). Bradycardia was seen secondary to S.B.E. but also simultaneously with or independent of S.B.E. Sudden asystole associated with S.B.E. was seen in one case. These results suggest an autonomic-nervous-system dysfunction in high-risk infants.

Twenty ASA I or II patients were studied to assess the safety of oxygenation for 4 min prior to intubing, so as to prevent the hypoxaemia related to tracheal intubation. The arterialized capillary blood saturation (Spo2) was continuously monitored with a pulse oximeter Nellcor 100 equipped with a finger probe. Patients spontaneously breathed oxygen (FIO2 = 1) while anaesthesia was induced with pancuronium bromide, thiopentone and fentanyl. Following apnoea, ventilation was manually controlled during 4 min (FIO2 = 1). The values of Spo2 were recorded before induction, at the end of the 4 min oxygenation period and after 5 min of apnoea. An arterial blood sample was withdrawn at the end of apnoea and analysed immediately using an OSM 2b hemoximeter. Apnoea was interrupted in case of desaturation below 95%, new arrhythmia or haemodynamic instability (blood pressure +/- 20% of control value). Mean saturation (+/- SD) before oxygenation was 98.6 +/- 1.35%. After oxygenating for 4 min, all the Spo2 reached 100%. After the 5 min apnoea period, no saturation was below 95% (mean +/- SD = 98.89 +/- 1.66); at this time, Sao2 and Spo2 did not significantly differ (p less than 0.001). In one case, apnoea had to be interrupted, because of the occurrence of arrhythmias, unrelated to a blood gas disorder (PaO2 = 225 mmHg; Paco2 = 34 mmHg; SaO2 = 100%; pH = 7.44). This study confirmed the efficacy and safety of oxygenating for 4 min before intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

A series of 235 consecutive patients refferred to the Stanford University Sleep Disorders Clinic with the complaint of excessive daytime sleepiness (EDS) were investigated extensively. A satisfactory final diagnosis involving a consistent syndrome or pathogenic process was made in all but 7 patients. In the course of this work a variety of tests, including prolonged polygraphic monitoring of multiple variables and CSF measurements before and after probenecid ingestion, were utilized. Different syndromes were confirmed (harmonious hypersomnia, subwakefulness syndrome); the definitions of others were clarified and extended (narcolepsy, drug dependency, periodic hypersomnia associated with menstruation, upper airway sleep apnea in children). Two new entities were tentatively identified (narcolepsy with sleep apnea, the neutral state syndrome). Narcolepsy and upper airway sleep apnea accounted for the majority of the cases (199). A strategic schema utilizing specific categories and frequency of occurrence in the case series is presented to improve the diagnosis of the complaint of excessive daytime sleepiness by the practicing physician. This case series was analysed in order to develop tentatively a meaningful nosology.

We have studied the sequence of events during prolonged apneic spells in two infants who, by virtue of multiple risk factors or ultimate death, were at risk for sudden death. Using techniques to quantitate airflow and pharyngeal airway pressures, we have reported many descriptive aspects of the apnea in these infants. Specifically, we have noted that severe apneic spells in these infants were accompanied by a wide spectrum of lengths and types of shorter apneas. In the case of infant A, the most severe spells occurred in clusters. Physiologic phenomena usually considered normal (sighs, swallows, etc.) often occurred in association with the apneic spells. In addition, we found that: 1) mixed apnea was the clinically significant form of apnea; 2) in mixed apnea, the site of obstruction was in the pharynx; 3) obstruction often occurred at the beginning of the spells; and 4) this obstruction occurred progressively over a series of breaths prior to the spell and resolved in a similar fashion. Theophylline, in one infant, decreased the incidence of apnea.