Cut-off points of neck and waist circumference as predictors of obstructive sleep apnea in the Colombian population: a comparison with polysomnography

ABSTRACT BACKGROUND: Neck circumference (NC) is a useful anthropometric measure for predicting obstructive sleep apnea (OSA). Ethnicity and sex also influence obesity phenotypes. NC cut-offs for defining OSA have not been established for the Latin American population. OBJECTIVES: To evaluate NC, waist circumference (WC), and body mass index (BMI) as predictors of OSA in the Colombian population and to determine optimal cut-off points. DESIGN AND SETTING: Diagnostic tests were conducted at the Javeriana University, Bogota. METHODS: Adults from three cities in Colombia were included. NC, WC, and BMI were measured, and a polysomnogram provided the reference standard. The discrimination capacity and best cut-off points for diagnosing OSA were calculated. RESULTS: 964 patients were included (57.7% men; median age, 58 years) and 43.4% had OSA. The discrimination capacity of NC was similar for men and women (area under curve, AUC 0.63 versus 0.66, P = 0.39) but better for women under 60 years old (AUC 0.69 versus 0.57, P < 0.05). WC had better discrimination capacity for women (AUC 0.69 versus 0.57, P < 0.001). There were no significant differences in BMI. Optimal NC cut-off points were 36.5 cm for women (sensitivity [S]: 71.7%, specificity [E]: 55.3%) and 41 cm for men (S: 56%, E: 62%); and for WC, 97 cm for women (S: 65%, E: 69%) and 99 cm for men (S: 53%, E: 58%). CONCLUSIONS: NC and WC have moderate discrimination capacities for diagnosing OSA. The cut-off values suggest differences between Latin- and North American as well as Asian populations.

Dispositivos de Avance Mandibular para el Manejo del Ronquido y la Apnea del Sueño. Actitudes de los Odontólogos Generales y los Especialistas Médicos para Proporcionarlos

RESUMEN: El objetivo de este estudio fue determinar las actitudes y la conciencia de los odontólogos y especialistas médicos sobre la provisión de dispositivos de avance mandibular (DAM) para el tratamiento de los ronquidos y la apnea del sueño. Se llevó a cabo un estudio observacional descriptivo de corte transversal, donde se seleccionaron por conveniencia 53 odontólogos (generales y especialistas) y 5 médicos especialistas en medicina del sueño en la ciudad de Guadalajara, México. Quienes respondieron un cuestionario específico desarrollado por Jauhar et al. (2008) dirigido a conocer la actitud de los odontólogos y médicos especialistas para la provisión de los DAM y otros aspectos relacionados con el ronquido y la apnea obstructiva del sueño (AOS). El 94 % de los odontólogos respondió estar interesado en capacitarse en ronquido y AOS. Y en el grupo de los médicos especialistas se encontró que el 80 % cree que los odontólogos sí tienen un papel para ayudar a los pacientes con ronquido y AOS, el 60 % cree que los odontólogos pueden contribuir con la realización de DAM y el 40 % considera que los odontólogos deben remitir a un especialista del sueño. Existe una actitud muy positiva de los odontólogos para ser parte del grupo interdisciplinario para el tratamiento del ronquido y de la apnea obstructiva del sueño, pero este estudio nos muestra además que a pesar de la disposición para utilizar los DAM, la formación y capacitación no es suficiente. Por otra parte, hay una actitud positiva de los médicos especialistas que consideran que los odontólogos juegan un papel importante en ayudar a los pacientes con ronquidos o con apnea del sueño, pero se evidencia que en su gran mayoría no usan los DAM como parte de un posible tratamiento.

ABSTRACT: The objective of this study was to determine the attitudes and awareness of dentists and medical specialists on the provision of mandibular advancement devices (MAD) for the treatment of snoring and sleep apnea. This is a cross-sectional descriptive observational study, where 53 dentists (general and specialists) and 5 sleep medicine specialists in the city of Guadalajara, Mexico were selected for convenience. The selected group answered a specific questionnaire developed by Jauhar et al., to know the attitude of dentists and medical specialists for the provision of MAD and other aspects related to snoring and obstructive sleep apnea (OSA). 94 % of dentists responded to be interested in training in snoring and OSA. And of the group of medical specialists, 80 % consider that dentists have a role in helping patients with snoring and OSA, 60 % believe that dentists can contribute to MAD and 40 % believe that dentists should refer a sleep specialist. There is a very positive attitude by the dentists to be part of the interdisciplinary group for the treatment of snoring and obstructive sleep apnea, but this study also shows that despite the willingness to use MAD, education and training is not enough. There is a positive attitude of specialist doctors who consider that dentists play an important role in helping patients with snoring or with sleep apnea, but it is evident that the majority do not use MAD as part of a possible treatment.

Diagnostic methods and criteria of obstructive sleep apnea hypopnea syndrome in children / 口腔疾病防治

@#Obstructive sleep apnea hypopnea syndrome (OSAHS), which is a common childhood disease, is a trending topic in clinical multidisciplinary research due to its detriment to the growth and development of children. Due to the wide variety and specificity of pathogenesis and clinical manifestations, the clinical diagnosis of OSAHS is sophisticated and difficult and remains controversial in the field. This review summarizes the common diagnostic methods in OSAHS for children, including polysomnography,which is known as the current “gold standard”, pulse oximetry, fiberoptic nasopharyngoscopy, nasopharyngeal lateral X-ray, CT, and magnetic resonance imaging (MRI). Furthermore, it emphasizes the new diagnostic critical value from Chinese guidelines for the diagnosis and treatment of obstructive sleep apnea in children (2020) for children with OSAHS released by China in 2020: the obstructive apnea hypopnea index (OAHI) is ≥ 1 time/h; it also emphasizes the importance of history and physical examination to contribute to clinical diagnosis and treatment for children with OSAHS.

Exames para o diagnóstico da síndrome da apnéia obstrutiva do sono: conhecimentos gerais para o cirurgião dentista que atua na área do sono / Investigations for the diagnosis of the syndrome obstructive sleep apnea: general knowledge for the dentist surgery that works in the sleep area

A Síndrome da Apneia e Hipopnéia Obstrutiva do Sono (SAHOS) foi descrita há quase três décadas na literatura, porém somente há pouco tempo tem conseguido o crescente interesse dos cirurgiões-dentistas; por isso foi feita esta revisão de literatura sobre a inter-relação entre a análise cefalométrica e os pacientes portadores desta patologia. Os estudos revisados mostram que existem diferenças significantes entre uma série de características da via aérea superior e das dimensões esqueléticas entre os pacientes com SAHOS e indivíduos normais. Foi observado que a análise cefalométrica tem sido utilizada como um importante meio auxiliar no diagnóstico e no planejamento do tratamento da Síndrome da Apneia e Hipopnéia Obstrutiva do Sono, associando um grande número de variáveis à prevalência desta síndrome. Esses conhecimentos básicos são de grande importância para o Cirurgião Dentista que atua na área da Odontologia do Sono(AU)

The Syndrome Obstructive Sleep Apnea (OSA) was described almost three decades ago in the literature, but only recently has stimulated a growing interest of dental surgeons; therefore was done this review of literature on the interrelationship between cephalometric analysis and patients with this pathology. The reviewed studies show that there are significant differences between a number of characteristics of the upper airway and skeletal dimensions between OSA patients and people in their normal stages. It was observed that the cephalometric analysis has been used as an important tool in the diagnosis and treatment planning Syndrome Obstructive Sleep Apnea, associating an extensive number of variables to the prevalence of this syndrome. This basic knowledge is of great importance for the Dental Surgeon who works in the area of Odontology Sleep(AU)

Trastornos respiratorios en niños con síndrome de Down / Respiratory disorders in children with down syndrome

Respiratory disorders in children with Down syndrome (DS) are common, and frequently undiagnosed. They often present sleep disordered breathing, respiratory tract infections and recurrent wheezing. Children with DS also have associated conditions that contribute to recurrent respiratory problems, such as hypotonia, immune disorders, congenital heart disease and gastroesophageal reflux. An adequate knowledge of all possible causes of respiratory pathology in children with DS is necessary, in order to allow a proper diagnosis, management and prevention of complications.

Los problemas respiratorios en niños con Síndrome de Down (SD) son frecuentes y muchos de ellos subdiagnosticados siendo los más habituales los trastornos respiratorios del sueño, infecciones respiratorias y sibilancias recurrentes. Los niños con SD, además, tienen condiciones asociadas que contribuyen a sus problemas respiratorios recurrentes, como hipotonía, alteraciones inmunes, cardiopatías congénitas y reflujo gastroesofágico. Se debe tener un adecuado conocimiento de todas las posibles causas de patología respiratoria en niños con SD, para hacer un adecuado diagnóstico, tratamiento y prevención de las complicaciones.

Role of Actinomyces and Helicobacter pylori in Obstructive Sleep Apnea Syndrome (OSAS) in Children.

Background: Obstructive hyperplasia causing obstructive sleep apnea syndrome (OSAS) is one of the most common conditions indicating tonsillectomy. Actinomycosis and H. pylori were assumed to have a role in tonsillar hyperplasia causing OSAS Purpose: Study the presence of Actinomyces and H. pylori in tonsils removed in children with OSAS. Methods: 50 children scheduled for tonsillectomy, all of these children had OSAS ± symptomatic adenoid enlargement. One tonsil, choosed randomly divided with a sterile blade into two parts: one half to be sent to pathology department (pathological examination) and the other half to clinical pathology (Rapid urease test and PCR). Results: Patients’ age was between 3 and 16 years (mean age was 5.38±2.74 years). 29 (61.7%) patients with Actinomyces in their tonsillar tissue were included in study group and 9 patients (64.7%) with H. pylori in their tonsillar tissue specimens were included in the second group. 3 patients were excluded from the study in whom both Actinomyces and H. pylori. Conclusion: The size of tonsils was significantly larger among cases with positive results to Actinomyces in comparison to cases to H. pylori. Further studies are needed to assure the role of actinomyces in pediatric tonsillar hypertrophy and whether control of Actinomycyes may reverse the problem or not.

Conducta perioperatoria en paciente con apnea obstructiva del sueño: A propósito de un caso / Perioperative behavior in a patient presenting with obstructive sleep apnea: With regard to a case

Introducción: A pesar de la alta frecuencia del síndrome de apnea - hipopnea obstructiva del sueño y de sus graves complicaciones perioperatorias, el riesgo de estos pacientes se subestima. Caso clínico: Hombre de 54 años, propuesto para herniorrafia incisional, con antecedentes de SHAOS y tratamiento con CPAP nasal; 6 puntos en la Escala de somnolencia de Epworth, obeso, fumador, consumidor frecuente de bebidas alcohólicas y dislipidémico; elementos clínicos de posible vía de aire difícil. Escala de evaluación de riesgo perioperatorio en pacientes con SAHOS 8 puntos (riesgo elevado). Se administró anestesia general balanceada (fentanilo, halotano, atracurio) y analgesia multimodal: morfina y bupivacaína por catéter epidural, nolotil y diclofenaco intravenosos. Tiempo quirúrcico 150 min. Se extubó y se colocó CPAP nasal en el postoperatorio inmediato. Se transfirió a Cuidados Intensivos por 24 hrs. La analgesia posoperatoria resultó satisfactoria y no se presentaron complicaciones; alta hospitalaria al sexto día de la cirugía. Desarrollo: Al elegir el método anestésico son varios los factores que influyen en la decisión y pocas las evidencias que fundamentan la superioridad de uno respecto a los demás. La experiencia del anestesiólogo, el tipo y localización de la intervención quirúrgica, la gravedad del SAHOS y la disponibilidad de recursos para atender a este tipo de pacientes durante todo el perioperatorio son claves para la elección. La consulta de los protocolos de actuación en pacientes con SHAOS permitió prever sus riesgos potenciales para la cirugía y seleccionar el plan anestésico, que adaptado a nuestras condiciones evitó posibles complicaciones.

Introduction: Despite the high frequency of the obstructive sleep apnea-hypopnea syndrome and of its perioperative severe complications, the risk of these patients is underestimated. Clinical case: Man aged 54, candidate to incisional herniorrhaphy with a history of sleep obstructive apnea and treatment with nasal continuous positive airway pressure six points in Epworth’s somnolence scale, obese, smoker, frequent consumer of alcohol and dyslipemic; clinical elements of possible difficult airway. The assessment scale of perioperative risk in SAHOS patients was of 8 points (high risk). Balanced general anesthesia was administered (fentanyl, halothane, atracurio) and multimodal analgesia” morphine and bupivacaine by epidural catheter, i.v. nolotil and diclofenac. Surgical time 150 min. Patient was extubated and placed in nasal CPAP during the immediate postoperative time. He was transferred to Intensive Care Unit for 24 hrs. Postoperative analgesia was satisfactory without complications; the hospital discharge was at sixth day postoperative. Development: Selecting the anesthetic method are some factors influencing in decision and not much evidences supporting the superiority of one regarding the others. The experience of the anesthesiologist, the type and location of surgical intervention, severity of SAHOS and availability of resources to care this type of patient over the perioperative time are key for choice. Consultation of performance protocols in patients presenting with SHAOS allowed to prevent its potential risks for surgery and to select the anesthetic plan, which adapted to our conditions avoided possible complications.

Aplicación de distracción osteogénica mandibular en niños con el síndrome de apnea obstructiva del sueño / Application of a mandibular osteogenic distraction in children with sleep obstructive apnea

Objetivos: mostrar los resultados de los primeros pacientes con síndrome de apnea obstructiva del sueño (SAOS) de tipo periférico esqueletal tratados en nuestro país con osteogénesis por distracción mandibular. Métodos: se trataron 9 pacientes con distracción osteogénica mandibular bilateral, con distractores marca Leibinger y Synthes. El periodo de latencia fue de 72 horas. La tasa de distracción mandibular, a razón de 1,0 mm cada 12 horas y la contención fue de 8 semanas. Luego se inició el tratamiento ortodóncico posquirúrgico. Se evaluaron los resultados a través de polisomnografía y estudios cefalométricos antes de la intervención, luego y al año del tratamiento. Resultados: el 89 por ciento de los casos fueron curados, el 11 por ciento tuvo mejoría. Dentro de las complicaciones encontradas, el 55 por ciento de los pacientes presentaron limitación temporal de la apertura bucal, que remitió con fisioterapia, y dos pacientes necesitaron traqueostomía con fines anestésicos. Conclusiones: la osteogénesis por distracción mandibular resultó ser un método terapéutico eficaz para el tratamiento del SAOS de tipo periférico, esqueletal(AU)

Objectives: to show the results from the first patients presenting with sleep obstructive apnea syndrome (SOAS) of skeletal peripheral type treated in our country with osteogenesis by mandibular distraction. Methods: Nine patients were treated with bilateral mandibular osteogenic distraction using Leibinger and Synthes distraction devices. Latency period was of 72 hours. Mandibular distraction rate at 1,0 mm each 12 hours and restraint was of 8 weeks. Then, postsurgical orthodontics treatment was started. Results were assessed by polysomnography and cephalometry studies before intervention, after it and at a year of treatment. Results: The 89 percent of cases had a good recovery, the 11 percent showed an improvement. Complications included: a temporary limitation of mouth opening in 55 percent disappearing with physiotherapy and two patients needed tracheostomy for anesthetic purposes. Conclusions: Osteogenesis by mandibular distraction was an effective therapeutical method for treatment of peripheral skeletal SOAS(AU)

Estudio piloto de marcadores inflamatorios en el sindrome de apnea obstructiva del sueño / Pilot study of inflammatory markers in the syndrome of obstructive sleep apnea

El síndrome de Apnea Obstructiva del Sueño (SAOS), consiste en la aparición repetida de episodios de obstrucción faríngea durante el sueño como consecuencia de un colapso de la vía respiratoria. La respuesta fisiológica a la hipoxia intermitente crónica es la generación de una respuesta inflamatoria local y sistémica. Se han evidenciado cambios importantes a nivel cardiovascular en pacientes con SAOS; sin embargo, se desconocen cuáles marcadores séricos y genéticos pudieran ser de utilidad. En el presente estudio, se presentan 15 marcadores séricos y 3 genéticos (IL-6, IL-1β y TNF-α) en un grupo de cinco pacientes para determinar cuáles pueden ser los marcadores de interés en la aparición y en el desarrollo de esta patología respiratoria. Se proponen como marcadores los niveles séricos: proteína C reactiva, TNFα, IL-6, el receptor soluble de TNF I, sCD62, sCD154, nitrotirosina y anti-oxLDL. Los niveles de IL-1 β, el receptor de TNF soluble II, sCD25, sCD54, nitritos y nitratos no parecieran ser buenos marcadores en SAOS. Los estudios genéticos no fueron concluyentes.

Obstructive sleep apnea syndrome (OSAS) is a repeated sequences of pharynx obstruction during sleep as a consequence of airway collapse. The physiological response to the desaturation is the generation of a local and systemic inflammatory immune response. Important changes at cardiovascular levels in patients with OSAS have been observed; however, it is not know which serum or genetic parameters could be useful. In the present study, we present 15 serum and 3 genetic (IL-6, IL-1β y TNF-α) markers in a group of five patients in order to determine which marker could be useful to study the genesis and progression of this respiratory pathology. The proposed serum markers are C reactive proteín, TNFα, IL-6, soluble de TNF receptor I, sCD62, sCD154, nitrotirosine and anti-oxLDL. The levels of IL-1 β, soluble TNF receptor II, sCD25, sCD54, nitrite y nitrate do not seem to be good markers for OSAS. The genetic studies were not conclusive.

O exercício da medicina do sono na clínica ortodôntica: pesquisas, protocolos e perspectivas / The exercise of sleep medicine in the orthodontic clinic: research, protocols and perspectives

A síndrome da apneia obstrutiva do sono é a categoria mais comum de distúrbios do sono, com alta taxa de mortalidade e morbidade, apresentando um cortejo sintomático que vai desde o ronco, presente na maioria dos casos, até a hipersonolência diurna, com repercussões comportamentais, cardiovasculares e neurológicas progressivas. Esse trabalho reflete sobre as conseqüências das últimas revisões sistemáticas acerca do estágio atual da terapia com aparelhos orais para distúrbios respiratórios do sono: seus limites e possibilidades, sua evolução histórica, científica e tecnológica, e os protocolos mais contemporâneos para lidar com a doença e sua sintomatologia. Como a ocorrência da síndrome está relacionada ao bloqueio total ou parcial das vias aéreas superiores durante o sono, os aparelhos odontológicos para uso noturno que fazem avanço mandibular podem oferecer melhora significativa dessa condição, com efeitos colaterais contornáveis, podendo compor o quadro de opções terapêuticas disponíveis em Medicina do Sono, desde que indicações coerentes, execução clínica especializada e testes de resolução sejam realizadas e novas perspectivas de atuação almejados.

Obstructive sleep apnea syndrome is the most common category of sleep-disordered breathing, with a high rate of mortality and morbidity, and a symptomatic trail that encompasses snoring which is present in about 95% of the cases, daytime excessive somnolence, with progressive behavioral, cardiovascular and neurological effects. This work reflects on the consequences of the last systematic revisions concerning the current stage of the intraoral appliances therapy, its limitations and indications, its historical, scientific and technological development, as well as the contemporary protocols to deal with the disease and its symptoms. As the occurrence of this syndrome is linked to the completed or partial blockage of the upper airways during sleep, the night use intraoral appliance that makes mandibular advancement can offer significant improvement of this condition, with controllable adverse effects, becoming an alternative amongst the treatments available within the Sleep Medicine, as long as it is provided with consistent treatment, specialized implementation and efficient clinical tests of the results and new perspective of performance longed for.

Avaliação do risco de síndrome da apneia obstrutiva do sono (SAOS) nos pacientes internados em spa de emagrecimento / Evaluation of the risk of sleep obstructive apnea syndrome (SOAS) in patients admitted in a slimming spa

Introdução: A associação entre a Síndrome de Apneia Obstrutiva do Sono (SAOS) e a obesidade tem sido muito estudada. A SAOS é caracterizada pela obstrução repetitiva da via aérea superior durante o sono, muitas vezes acompanhada de roncos, dessaturação de oxigênio, fragmentação do sono e sonolência excessiva diurna (SED). Tipo do Estudo: Transversal Prospectivo. Objetivo: Analisar os resultados do Questionário de Berlim (QB) e da Escala de Sonolência de Epworth(ESE) preenchidos pelos pacientes internados no Spa Med Campus Sorocaba, procurando encontrar quais deles possuem sonolência diurna e alto risco para SAOS. Método: Os pacientes responderam voluntariamente aos Questionários de Berlim e ESE. O estudo foi do tipo transversal, com análise dos questionários preenchidos durante o ano de 2008. Resultados: Obtivemos um total de 276 pacientes, com um total de 183 mulheres e 93 homens. A prevalência de obesos foi de 111 pacientes (40,2%). No grupo QB positivo, obtivemos 84 pacientes no total; sendo 34 homens, quanto ao grupo ESE positivo, encontramos no total 67 pacientes, sendo 24 homens. Conclusão: A ESE e o QB têm servido atualmente de triagem para os distúrbios do sono e pode servir como possível indicador para a polissonografia. Os resultados dos questionários nos mostram a alta prevalência de indivíduos internados em SPA com risco de apresentar SAOS, especialmente os obesos.

Introduction: The association between Sleep Obstructive Apnea Syndrome (SOAS) and the obesity has been highly studied. The SOAS is characterized by the repetitive obstruction of the upper airways during the sleep, many times accompanied by snores, oxygen desaturation, sleep fragmentation and excessive daytime somnolence (EDS). Type of Study: Prospective Transversal. Objective: To analyze the results of the Berlin Questionnaire (BQ) and the Epworth Somnolence Scale (ESS) completed by the patients interned in the Spa Med Campus Sorocaba, attempting to find who has daytime somnolence and high risk for SOAS. Method: The patients completed the Berlin Questionnaire and the ESS voluntarily. The study was of transversal type with analysis of the questionnaires completed during the year of 2008. Results: We obtained a total of 276 patients with a total of 183 women and 93 men. The prevalence of obese patients was of 111 patients (40.2%). In the positive BQ group, we obtained a total of 84 patients; 34 male; as to the positive ESS group, we found a total of 67 patients, 24 male. Conclusion: The ESS and the BQ have been useful currently for selection of the sleep disorders and may serve as a possible indicator for polysonography. The questionnaires' results show us the high prevalence of individuals interned in SPA with the risk of having SOAS, specially the obese ones.

Apnea obstructiva del sueño. Hora de ser tomado en serio por los anestesiólogos / Sleep obstructive apnea is a serious matter that must to be considered by anesthesiologists

Introducción: El mantenimiento de la permeabilidad de las vías aéreas superiores es una preocupación compartida por los anestesiólogos y por los médicos involucrados con los disturbios del sueño. Los pacientes con apnea obstructiva del sueño son más susceptibles de presentar obstrucción de las vías respiratorias, principalmente cuando se asocian al efecto depresor de fármacos usados en sedación o anestesia. Objetivo: Realizar una puesta al día sobre la relación entre apnea obstructiva del sueño y anestesia, así como planificar la conducta anestésica y tratamiento perioperatorio. Desarrollo: Se describe la conducta perioperatoria de los pacientes con apnea obstructiva del sueño que requieren uso de anestesia por cualquier causa. Conclusiones: La apnea obstructiva del sueño es una entidad que aumenta el riesgo quirúrgico y que requiere consideraciones especiales en todas las fases de la anestesia.

Introduction: High airways permeability maintenance is a concern shared by anesthesiologists and by physicians involved in sleep disturbances. Patients presenting with sleep obstructive apnea are more liable to present airways obstruction, mainly when are associated with depressor effect of drugs used in sedation or analgesia procedures. Aim: To make an updating on relation between sleep obstructive apnea and anesthesia, as well as how to plan the anesthetetic behavior of patients with this condition requiring the use of anesthesia from any cause. Conclusions: Sleep obstructive apnea is an entity increasing the surgical risk and requiring special considerations in all anesthesia phases.

Influence of renal denervation on blood pressure, sodium and water excretion in acute total obstructive apnea in rats

Obstructive apnea (OA) can exert significant effects on renal sympathetic nerve activity (RSNA) and hemodynamic parameters. The present study focuses on the modulatory actions of RSNA on OA-induced sodium and water retention. The experiments were performed in renal-denervated rats (D; N = 9), which were compared to sham (S; N = 9) rats. Mean arterial pressure (MAP) and heart rate (HR) were assessed via an intrafemoral catheter. A catheter was inserted into the bladder for urinary measurements. OA episodes were induced via occlusion of the catheter inserted into the trachea. After an equilibration period, OA was induced for 20 s every 2 min and the changes in urine, MAP, HR and RSNA were recorded. Renal denervation did not alter resting MAP (S: 113 ± 4 vs D: 115 ± 4 mmHg) or HR (S: 340 ± 12 vs D: 368 ± 11 bpm). An OA episode resulted in decreased HR and MAP in both groups, but D rats showed exacerbated hypotension and attenuated bradycardia (S: -12 ± 1 mmHg and -16 ± 2 bpm vs D: -16 ± 1 mmHg and 9 ± 2 bpm; P < 0.01). The basal urinary parameters did not change during or after OA in S rats. However, D rats showed significant increases both during and after OA. Renal sympathetic nerve activity in S rats increased (34 ± 9 percent) during apnea episodes. These results indicate that renal denervation induces elevations of sodium content and urine volume and alters bradycardia and hypotension patterns during total OA in unconscious rats.

The Influences of Obstructive Apneas on Changes of Cardiovascular Function in Anesthetized Dogs with alpha-chloralose / 결핵

BACKGROUND: Patients with obstructive sleep apnea syndrome are known to have high long-term mortality compared to healthy subjects because of their cardiovascular dysfunction. The observation of hemodynamic changes by obstructive apneas is helpful to understand when attempting to understand the pathophysiological mechanism of the development of cardiovascular dysfunction in those patients. Therefore, we studied the changes of in cardiovascular function with the an animal model and tried to obtain the basic data for an ideal experimental model (this phrase is unclear), which is required a requirement for the a more advanced study. METHODS: In 16 Sixteen anesthetized dogs with alpha-chloralose, experimental subjects (delete) were divided into two groups : 8 dogs of room air breathing group and 8 dogs of oxygen breathing group. We measured PaO2, PaCO2, heart rate, cardiac output, mean femoral artery pressure, and mean pulmonary artery pressure at specified times during the apnea-breathing cycle : before endotracheal tube occlusion (baseline), 25 seconds after endotracheal tube occlusion (apneic period), 10 seconds (early phase of postapneic period, EPA) and 25 seconds (late phase of postapneic period, LPA) after spontaneous breathing. RESULTS: In room air breathing group, the heart rate significantly decreased significantly decreased at during the apneic period compared to that at baseline (P<0.01) and increased at EPA and LPA compared to that during the apneic period (P<0.01). But, the heart rate showed no significant changes during apneic and postapneic periods in the oxygen breathing group. Cardiac output tended to decrease at during apneic period compared to that at baseline, but did not show statistical significance was statistically significant. Cardiac output significantly decreased at LPA compared to at baseline (P<0.01). Mean femoral artery pressure was significantly decreased at during apneic period compared to that at baseline (P<0.05). CONCLUSION: Through this experiment, we were partially able to understand the changes of cardiovascular function indirectly, but it is suggested that the (delete) new experimental animal model displaying physiological mechanism close to sleep in nature might natural sleep should be established (,)and the advanced study of in the changes of cardiovascular function and its cause their causes should be continued.

The Changes of Percutaneous Oxygen Saturation Following Obstructive Apnea in Infants / 대한마취과학회지

Preoxygenation is a standard anesthetic technique which prevents significant hypoxemia during the induction of anesthesia. Complete oxygenation is especially important in clinical situations of difficult intubation or in patients with decreased FRC, and in siturations where oxygen saturation is critical. During the induction of anesthesia in children, airway obstruction and apnea are associated with rapid development of hypoxemia. The decreasing speed of oxyhemoglobin saturation was faster in smaller infants than bigger infants. The most important factor determining the speed with which hypoxemia develops in healthy children is probably the oxygen reserve contained in the lungs and its relation to the oxygen consumption of the child. With deaeasing age, the arterial oxygen consumption increases and the ratio of FRC to body weight decreases. Due to the anatomical structure of an infant's upper airway, it is more difficult to obtaine patient airway in infants than in children. During repeated atttempts to intubate the trachea or while waiting for recovery from laryngeal spasms hypoxia can occur easily resulting in visible cyanosis in infants. This study was carried out to measure the time permissible for apnea before occurance of hypoxia following full oxygenation. The subjects consisted of 6 randomly selected infants 1-2 month of age, 4.6+/-0.6 Kg of body weight with no abnormalities of cardiorespiratory functions. After the intramuscular injection of atropine, patients were anesthetized through mask using oxygen and halothane. SpO2 and pulse rates were recorded throughout the study. After the patients were intubated, a plug was placed on the distal end of the tube to induce obstructive apnea. As soon as SpO2 decreased to just below 90%, the patients were ventilated again. In 2 of the infants, the time required to obtaine 90% saturation was 60 seconds. Within less than 70 seconds, four out of 6 infants had SpO2 below 90% and SpO2 below 80% were noticed in 3 cases. After the reestablishment of ventilation, SpO2 returned to the preapneic value within 10 second in all subjects. There was no evidence of increasing pulse rate as SpO2 levels decreased. However, pulse rate decreased in all subjects thoughout the study. In summary, maximum time permissible for apnea in neonate and young infant is approximately one minute. Furthermore, tachycardia should not be used as a sign for the onset of hypoxia.

Arterial Oxygen Desaturation Rate Following Obstructive Apnea in Parturients / 대한마취과학회지

Preoxygenation is a standard anesthetic technique for preventing a significant hypoxemia during the induction of anesthesia. Complete denitrogenation is especially important in clinical situations of difficult intubation or in patients with decreased functional residual capacity, and in situations where oxygen saturation is critical. Oxygen consumption in pregnancy is markedly increased at term as compaired to the nonpregnant stage. It is important to evaluate how long parturient women can withstand apneic hypoxemia during induction of general anesthesia. This study was carried out to measure the duration of time required to decrease the SaO2 to 90% After written informed consent was obtained from six healthy parturients who were to under go elective Cesarean section and six healthy non-pregnant women who were to have total abdominal hysterectomies. All subjects had a tight fitting anesthesia mask applied and breathed 100% oxygen, and a single isolated apnea was carried out. Arterial oxygen saturation and gas tensions were measured at a time SaO2 decreased to 90%, also blood gas data of 4 minutes after apnea in the non-pregnant women were obtained. From these, arterial oxyhemoglobin content was calculated, and mean desaturation rate from denitrogenation to the time SaO2 decreased to 90% was calculated. The mean time to obtain 90% saturation was 7.5+/-0.9 minutes in the nonpregnant women and 3.6+/-0.8 minutes in the parturient group. The mean slope of desaturation was steeper in the paturient(-3.336) than the nonpregnant (-1.52). The PaO2 inereased over 400mmHg in both the groups after denitrogenatio. After 4 minutes of apnea, the mean PaO2 decreased to 200mmHg in the non-pregnant women. The rate of rise of alveolar PCO2 during apnea were alower in the non-pregnant women(2.8+/-1.2mmHg/minute) than in the parturient women(6.8+/-1.8mmHg/minute). This study demonstrates that the rate of oxygen desaturation is faster in the parturients than the nonpregnant women. It is suggested that those results came out because of pregnancy-in-duced increase of oxygen consumption rate and decrease in FRC. The results of this study show the induction for term parturients should be speeded up with caution after full oxygenation in comparison with non-pregnant patients.