Fisiología respiratoria: fisiopatología de las enfermedades obstructivas / Pathophysiology of obstructive diseases

Las enfermedades obstructivas de la vía aérea pediátrica son muy frecuentes debido a los fenómenos mecánicos que están involucrados. En los niños más pequeños, la marcada resistencia de las vías aéreas pequeñas, determinada por la falta de tejido elástico y una caja torácica aún no bien desarrollada; tanto su estructura como la musculatura, facilitarán que cuadros infecciosos, mecánicos (cuerpo extraño) y compresivos, determinen que los flujos de aire se vean limitados y con ello la ventilación alveolar. La respuesta fisiológica con aumento del trabajo respiratorio es limitada y por lo tanto la fatiga muscular determinará hipoventilación con las consecuencias de hipoxemia e hipercapnia.

Obstructive diseases of the pediatric airway are very frequent due to the mechanical phenomena that are involved. The marked resistance of the small airways, such as the lack of elastic tissue and a thoracic cage that is not yet well developed, both in its structure and in the musculature, will make it easier for infectious, mechanical (foreign body), compressive and other conditions to determine that the flows of air are limited and with it the alveolar ventilation. The physiological response with increased work of breathing is limited and therefore muscle fatigue will determine hypoventilation, with the consequences of hypoxemia and hypercapnia.

Fisiología respiratoria hipoxemia / Hypoxemia

La hipoxemia ocurre producto de una inadecuada captación de oxígeno a nivel pulmonar y se manifiesta como presión arterial de oxígeno menor a 60 mmHg o saturación arterial de oxígeno menor de 90%. Los mecanismos fisiopatológicos por los cuales se puede producir hipoxemia son hipoventilación, alteración del equilibrio ventilación perfusión, shunt cardiaco, alteración de la difusión y disminución de la presión inspirada de oxígeno. La comprensión de estos mecanismos es fundamental para entender su presentación clínica en distintas enfermedades.

Hypoxemia is the name given to inadequate uptake in the lung and is defined as an arterial oxygen pressure less than 60 mmHg or arterial oxygen saturation less than 90%. The pathophysiological mechanisms that can produce hypoxemia are: hypoventilation, ventilation perfusion mismatch, cardiac shunt, diffusion impairment and decreased inspired oxygen pressure. Full comprehension of these mechanism facilitates the understanding of hypoxemia among different diseases.

Hipoventilação relacionada ao sono de origem central secundária à deficiência de biotinidase: relato de caso / Sleep-related hypoventilation due to partial biotinidase deficiency: a case repor

RESUMO: A hipoventilação relacionada ao sono de origem central resulta em hipercapnia relacionada ao sono na vigência de condições normais do sistema respiratório e excluindo-se outros fatores. Os pacientes portadores dessa patologia podem se apresentar assintomáticos ou com queixas de cefaleia matinal, déficit cognitivo e fadiga, além de eventos como a observação de respiração superficial. No presente relato, descreve-se o caso de uma paciente de três anos, com exame físico geral e neurológico normais, desenvolvimento neuropsicomotor adequado, apresentando irregu-laridades respiratórias e bradicardia durante o sono. Encaminhada para investigação de distúrbios respiratórios do sono, sendo diagnosticada com hipoventilação relacionada ao sono. Através do estudo genético, evidenciou-se a deficiência de biotinidase como a possível causa da sintomatologia, comprovada por dosagens enzimáticas e teste genético molecular. O tratamento medicamentoso foi iniciado precocemente, determinando resolução dos sintomas descritos. A importância do presente relato se encontra na apresentação da deficiência da biotinidase com quadro cardiorrespiratório isolado em criança neurologicamente normal, ademais trata-se de um caso em que a etiologia de Breath-Holding Spells foi a deficiência dessa enzima. Correspondência sugerida pela resolução da hipoventila-ção central após a introdução da biotina. Além disso, nesse caso, os sintomas Apparent Life-Threatening Events, que aterrorizam o observador e até o profissional, foram solucionados com tratamento simples, a ingesta oral de biotina. Esse relato de caso corrobora com a expansão das possibilidades de manifestações fenotípicas das formas tardias de deficiência de biotinidase, como o fenótipo da Síndrome da Hipoventilação Central. (AU)

ABSTRACT: Idiopathic sleep-related hypoventilation occurs in individuals with hypercapnia during sleep in normal conditions of the respiratory system in the absence of other disorders. Patients with this condition may be asymptomatic or have complaints of morning headache, cognitive deficit and fatigue, and observation of shallow breathing. This report describes the case of a 3-year-old patient with normal physical and neurological exam, appropriate neuropsychomotor development, presenting breathing irregularities, and bradycardia during sleep. The patient was referred to an investigation for sleep respiratory disturbs and was diagnosed with hypoventilation related to sleep. The genetic study, done by enzymatic dosages and molecular genetic tests, showed the deficiency of biotinidase as a possible cause of symptomatology. The drug treatment was initiated early with the resolution of the symptoms. The present clinical report highlights the biotinidase deficiency with an isolated cardiorespiratory condition in a neurologically normal child, which also led to Breath-Holding Spells. This relation was suggested after central hypoventilation resolution following biotin introduction. Besides, Apparent Life-Threatening Events symptoms, which terrify the observer and even professionals, disappeared after the oral intake of biotin. Finally, this case report corroborates the expansion of possibilities for the phenotypic manifestations of late cases from biotinidase deficiency, as the SHC phenotyp. ((AU)

Trastorno de hipoventilación central del sueño en pediatría: causas poco frecuentes / Central hypoventilation disorders sleep-related in pediatrics: unusual causes

Congenital central hypoventilation syndrome (CCHS) and rapid-onset obesity syndrome with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) are rare causes of hypoventilation during sleep in the pediatric population. This group of disorders are characterized by the absence or decrease in the automatic control of ventilation, decreased sensitivity of chemoreceptors to CO2, causing hypoventilation during sleep and even in wakefulness, in the most severe cases. For these reasons it is important to diagnose and treat them promptly. The objective of this review is to provide current and complete literature, to be able to identify, treat and refer this group of children early, and thus reduce the complications and/or associated comorbidities in the short and long term, improving their quality of life.

El síndrome de hipoventilación central congénita (CCHS) y síndrome de obesidad de inicio rápido con disfunción hipotalámica, hipoventilación y desregulación autonómica (ROHHAD), son causas poco comunes de hipoventilación durante el sueño en la población pediátrica. Este grupo de trastornos se caracterizan por ausencia o disminución en el control automático de la ventilación, sensibilidad disminuida de los quimioreceptores al CO2, provocando hipoventilación durante el sueño e incluso en vigilia, en los casos más severos. Por estas razones es importante diagnosticarlos y tratarlos oportunamente. El objetivo de esta revisión es proporcionar literatura actual y completa, para poder identificar, tratar y referir a éste grupo de niños tempranamente, y así disminuir las complicaciones y/o comorbilidades asociadas a corto y largo plazo, mejorando su calidad de vida.

Fever for 2 months and disturbance of consciousness for 1 week in a preschool-aged girl / 中国当代儿科杂志

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation syndrome (ROHHADS) is a rare multi-system disease, and delayed diagnosis and treatment may lead to catastrophic cardiopulmonary complications. As far as we know, no patient with ROHHADS has been reported in China, and this article reports a child with ROHHADS to improve the awareness of this disease among clinicians. A girl, aged 3 years, had the clinical manifestations of rapid weight gain, fever, disturbance of consciousness, and convulsion. The physical examination showed a body weight of 20 kg, somnolence, irregular breathing, and stiff neck. She had increased blood levels of prolactin and follicle-stimulating hormone and hyponatremia. The lumbar puncture showed an increased intracranial pressure. The brain MRI and magnetic resonance venography showed symmetrical lesions in the periventricular region and venous thrombosis in the right transverse sinus and the superior sagittal sinus. The sleep monitoring showed hypopnea. The girl was finally diagnosed with ROHHADS and intracranial venous thrombosis. She recovered after symptomatic treatment including decreasing intracranial pressure, anticoagulation, and respiratory support. The possibility of ROHHADS should be considered for patients with unexplained obesity, fever, and hypoventilation, with or without central nervous system symptoms. Early diagnosis and standardized follow-up can improve the prognosis of children with ROHHADS.

Ondine's curse: the origin of the myth / La maldición de Ondina: el origen del mito

ABSTRACT Central alveolar hypoventilation syndrome has been known for decades as Ondine's curse. It was named as such after a German myth. Although most of the stories resemble one another, word of mouth has led to misinterpretation of this tale among the medical community. The present paper reviews the original narrative, its characters, and how it is linked to the most relevant aspects of the disease.

RESUMEN El síndrome de hipoventilación alveolar central (por sus siglas en inglés) se conoce desde hace décadas como la maldición de Ondine. Fue nombrado como tal por un antiguo mito alemán. Aunque la mayoría de las historias se parecen, la tradición oral ha llevado a una mala interpretación de esta historia entre la comunidad médica. El presente artículo revisa la narrativa original, sus personajes y su relación con los aspectos más relevantes de la enfermedad.

Marcapasos diafragmático en paciente pediátrico con síndrome de Hipoventilación Central Adquirido / Diaphragm pacing in a pediatric patient with Acquired Central Hypoventilation syndrome

Resumen: Introducción: El marcapasos diafragmático permite reducir o eliminar la necesidad de ventilación mecánica en pacientes con insuficiencia respiratoria crónica que conservan el eje nervio frénico-diafragma in tacto, siempre que no presenten enfermedad pulmonar intrínseca. Aunque su implantación ha sido practicada por décadas, su uso no está ampliamente difundido, y existe poca literatura pu blicada al respecto, la mayoría relacionada con lesión medular alta y síndrome de hipoventilación central congénito. Objetivo: Describir una experiencia de implantación de marcapasos diafragmático en paciente pediátrico con síndrome de hipoventilación central adquirido. Caso Clínico: Pa ciente femenino con síndrome de hipoventilación central secundario a lesión isquémica de tronco cerebral como resultado de disfunción de válvula de derivación ventrículo peritoneal, motivo por el cual durante 5 años se mantuvo con asistencia de ventilación mecánica intrahospitalaria. A los 7 años de edad se implantó marcapasos diafragmático mediante cirugía toracoscópica, lo que per mitió posterior a un periodo de rehabilitación y acondicionamiento respiratorio el destete de la ventilación mecánica y el egreso hospitalario. Conclusiones: El marcapasos diafragmático es una opción factible, potencialmente segura y costo efectiva para disminuir o eliminar la dependencia de ventilación mecánica y mejorar la calidad de vida en pacientes con síndrome de hipoventilación central adquirido.

Abstract: Introduction: Diaphragmatic pacemaker is a device that reduces or eliminates the need of mechanical ventilation in patients with chronic respiratory failure who keep the phrenic nerve-diaphragm axis intact, as long as they do not present intrinsic lung disease. Although its implantation has been practiced for deca des, its use is not widespread and to date, there is little published literature about it, mostly related to high spinal cord injury and congenital central hypoventilation syndrome. Objective: To describe an experience of diaphragmatic pacemaker implantation in a pediatric patient with acquired cen tral hypoventilation syndrome. Clinical Case: Female patient with central hypoventilation syndrome secondary to ischemic brainstem lesion as a result of ventriculoperitoneal shunt malfunction. For this reason, for 5 years she was supported by inpatient mechanical ventilation. At 7 years of age, a diaphragmatic pacemaker was implanted by thoracoscopic surgery, which allowed, after a period of rehabilitation and respiratory conditioning, mechanical ventilation withdrawal, and hospital dischar ge. Conclusions: Diaphragmatic pacemaker is a feasible, potentially safe, and cost-effective option for decreasing or eliminating mechanical ventilation dependence and improve life quality in patients with acquired central hypoventilation syndrome.

Síndrome de Ondina (hipoventilación central congénita), una amenaza contra la vida al dormir / Ondina syndrome (congenital central hypoventilation) a threat against life when sleeping

RESUMEN El síndrome de Ondina, o síndrome de hipoventilación central congénita, es una enfermedad neurológica rara, donde hay fracaso en el control de la ventilación en el sistema nervioso central, llevando a la hipoxia e hipercapnia que pueden generar problemas del neurodesarrollo y, finalmente, ocasionar la muerte. Puede representar una situación muy dolorosa para los familiares de los pacientes que la padecen, despertando sentimientos difíciles de enfrentar, es por esto que es importante tener conocimiento acerca de esta condición para así impactar en la disminución de su incidencia.

SUMMARY Ondina syndrome, or congenital central hypoventilation syndrome, is a rare neurological disease in which there is a failure in the control of ventilation in the central nervous system, which leads to hypoxia and hypercapnia leading to neurodevelopmental problems and ultimately to death. It can represent a very painful situation for the family of patients who suffer from it, awakening feelings that are difficult to face. Thus, it is important to have adequate knowledge of this condition in order to have an impact on the decrease of its incidence.

Cuidados de Enfermería en pacientes con ventilación mecánica invasiva en la Unidad de Cuidados Intensivos Pediátricos / Nursing Care in patients with invasive mechanical ventilation in the Pediatric Intensive Care Unit

La rehabilitación cardiometabólica es un programa multifactorial útil para el tratamiento de las principales patologías que tienen una relación directa con el sedentarismo, como patologías cardiovasculares, metabólicas y sus complicaciones. En mayo de 2004, durante la 57ª Asamblea Mundial de la Salud, se aprobó "La estrategia mundial de la Organización Mundial de la Salud (OMS) que aborda sobre el régimen alimentario, la actividad física y la salud" con la finalidad de disminuir la inactividad física, los malos hábitos de alimentación que de forma directa llevan al exceso de peso, y que están asociadas al riesgo cardiovascular (RCV), a las enfermedades cardiovasculares, a la diabetes mellitus (DM) del tipo 2 y a otras diferentes enfermedades degenerativas crónicas. En base a la cual se orienta a implementar una correcta prescripción del ejercicio tanto preventiva como terapéutica. Este protocolo de atención clínico-terapeútico va dirigido a profesionales de la salud para el control de enfermedades cardiometabólicas. Los profesionales sanitarios podrán ofertar una terapéutica integral a sus pacientes para dosificar el ejercicio de forma personalizada, a partir del estado de salud, conocimiento de patologías preexistentes, edad y condición física inicial del paciente, así como proporcionar un seguimiento mediante programas individualizados. Cuyo principal fin es mejorar la condición cardiovascular, evitar nuevas complicaciones y reducir la mortalidad.

Cardiometabolic rehabilitation is a multifactorial program useful for the treatment of the main pathologies that have a direct relationship with sedentary lifestyle, such as cardiovascular, metabolic pathologies and their complications. In May 2004, during the 57th World Health Assembly, "The World Strategy of the World Health Organization (WHO) that addresses the diet, physical activity and health" was approved in order to reduce the physical inactivity, poor eating habits that directly lead to excess weight, and that are associated with cardiovascular risk (CVR), cardiovascular diseases, diabetes mellitus type 2 and other different chronic degenerative diseases . Based on which it is oriented to implement a correct prescription of both preventive and therapeutic exercise.This protocol of clinical-therapeutic care is aimed at health professionals for the control of cardiometabolic diseases. Health professionals may offer a comprehensive therapy to their patients to dose the exercise in a personalized way, based on the state of health, knowledge of preexisting pathologies, age and initial physical condition of the patient, as well as providing follow-up through individualized programs. Whose main purpose is to improve the cardiovascular condition, avoid new complications and reduce mortality.

Factors Affecting the Response to First-Line Treatments in Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis

BACKGROUND AND PURPOSE: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common type of autoimmune encephalitis. This study aimed to explore the possible factors affecting the response to first-line treatments in patients with anti-NMDAR encephalitis. METHODS: We enrolled 29 patients who were diagnosed as anti-NMDAR encephalitis between January 1, 2015, and June 30, 2018. They were divided into the remission and nonremission groups according to their response to first-line treatments. The demographics, clinical manifestations, main ancillary examinations, follow-up treatments, and prognosis of patients were recorded. The symptoms reported on in this study occurred before treatments or during the course of first-line treatments. RESULTS: There were 18 patients (62.07%) in the remission group and 11 patients (37.93%) in the nonremission group. Compared to the remission group, a higher proportion of the patients in the nonremission group exhibited involuntary movements, decreased consciousness, central hypoventilation, lung infection, and hypoalbuminemia. The nonremission group had a high incidence of increased intracranial pressure and significant elevations of the neutrophil-to-lymphocyte ratio in peripheral blood (NLR), aspartate aminotransferase, and fibrinogen. Six patients (54.55%) in the nonremission group received second-line immunotherapy. Only one patient (3.45%) died, which was due to multiple-organ failure. CONCLUSIONS: Anti-NMDAR-encephalitis patients with more symptoms—especially involuntary movements, disturbance of consciousness, central hypoventilation, and accompanying hypoalbuminemia and pulmonary infection—may respond poorly to first-line treatments. Positive second-line immunotherapy therefore needs to be considered. Admission to an intensive-care unit, increased cerebrospinal fluid pressure, and increased NLR might be the significant factors affecting the response to first-line treatments.

Spinal anesthesia and postoperative epidural analgesia in a patient with congenital central hypoventilation syndrome: a case report / 대한마취과학회지

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by alveolar hypoventilation and autonomic dysregulation. Patients with CCHS have adequate ventilation while awake but exhibit hypoventilation while asleep. More severely affected patients exhibit hypoventilation both when awake and when asleep. CASE: Here, we report a case of successful spinal anesthesia and postoperative epidural analgesia in a patient with CCHS who underwent orthostatic surgery. CONCLUSIONS: In patients with CCHS, anesthesia is used with the goal of minimizing respiratory depression to avoid prolonged mechanical ventilation. Regional anesthesia should be considered where appropriate. Continuous oxygen saturation and end-tidal carbon dioxide monitoring must be available.

Central Hypoventilation Syndrome in Posterior Circulation Stroke Treated by Respiratory Rehabilitation: a Case Report

Central hypoventilation syndrome is a rare and fatal condition resulting from various central nervous system disorders that is characterized by a failure of automatic breathing. We report a case of central hypoventilation syndrome following posterior circulation stroke whose pulmonary function was improved by respiratory rehabilitation. A 59-year-old woman with a history of hemorrhagic stroke of the bilateral cerebellum was hospitalized due to pneumonia. A portable ventilator was applied via tracheostomy, recurrent episodes of apnea and hypercapnia impeded weaning. A respiratory rehabilitation program including chest wall range of motion exercise, air stacking exercise, neuromuscular electrical stimulation (NMES) on abdominal muscles, upper extremity ergometer, locomotor training, high-frequency chest wall oscillator, mechanical insufflation, and exsufflation was employed, as spirometry showed a severe restrictive pattern. A spontaneous breathing trial was started, and a portable ventilator was applied for 8 hours, only during nighttime, to prevent sudden apneic event. After 4 weeks of treatment, follow-up spirometry showed much improved respiratory parameters. This case suggests that respiratory rehabilitation can improve pulmonary function parameters and quality of life in central hypoventilation syndrome.

Respiratory Responses during Exercise in Self-contained Breathing Apparatus among Firefighters and Nonfirefighters

BACKGROUND: Firefighters are required to use self-contained breathing apparatus (SCBA), which impairs ventilatory mechanics. We hypothesized that firefighters have elevated arterial CO₂ when using SCBA. METHODS: Firefighters and controls performed a maximal exercise test on a cycle ergometer and two graded exercise tests (GXTs) at 25%, 50%, and 70% of their maximal aerobic power, once with a SCBA facemask and once with protective clothing and full SCBA. RESULTS: Respiratory rate increased more in controls than firefighters. Heart rate increased as a function of oxygen consumption (V.(O₂)) more in controls than firefighters. End-tidal CO₂ (ETCO₂) during the GXTs was not affected by work rate in either group for either condition but was higher in firefighters at all work rates in both GXTs. SCBA increased ETCO₂ in controls but not firefighters. CONCLUSIONS: The present study showed that when compared to controls, firefighters’ hypoventilate during a maximal test and GXT. The hypoventilation resulted in increased ETCO₂, and presumably increased arterial CO₂, during exertion. It is proposed that firefighters have altered CO₂ sensitivity due to voluntary hypoventilation during training and work. Confirmation of low CO₂ sensitivity and the consequence of this on performance and long-term health remain to be determined.

Cuidados respiratorios para pacientes con enfermedades neuromusculares / Respiratory care for patients with neuromuscular diseases

Non-invasive respiratory care, combining with ventilatory support, initially at night and then during 24 hours/day, even in patients with minimal vital capacity and the implementation of specifics techniques like mechanically assisted coughing, glossopharyngeal breathing and air stacking, have contributed to a better quality of life and survival of patients with neuromuscular diseases. It is essential for health care professionals to know all the therapeutic possibilities for their patients and their families, so as the disease progresses it would facilitate their decision-making. Technological advances and proper training for patients and caregivers facilitate the stay at home and promote their autonomy and integration, without depending on hospital nor permanent nursing care. In November 2016 it was carried out the Noninvasive Ventilatory Support workshop/meeting with more than 200 physicians, physiotherapists, respiratory therapists and nurses in Montevideo, Uruguay. It was conducted by Dr. John Robert Bach, Medical Director of the Center for Non-Invasive Mechanical Ventilation at Rutgers New Jersey School of Medicine in Newark, New Jersey. Dr Bach is recognized worldwide for his extensive background in studies and publications on noninvasive ventilation and neuromuscular diseases.

Los cuidados respiratorios no invasivos, combinando la asistencia ventilatoria, inicialmente nocturna y luego durante las 24 h del día, incluso en pacientes con capacidad vital mínima, más la implementación de estrategias complementarias de tos asistida, respiración glosofaríngea y apilamiento de aire (air stacking) en forma activa o pasiva han contribuido a una mejor calidad de vida y sobrevida de los pacientes con enfermedades neuromusculares. Resulta esencial que los profesionales de la salud, conozcan todas las opciones terapéuticas al informar a sus pacientes y sus familias, de modo que ellos puedan tomar sus mejores decisiones en la medida que la debilidad e hipoventilación progresen. Los avances tecnológicos, la capacitación de los pacientes y sus cuidadores facilitan su estadía en el hogar sin depender de instituciones o cuidados de enfermería permanentes, promoviendo su autonomía e integración, disminuyendo el riesgo de falla respiratoria conducente a intubación endotraqueal y/o a traqueostomia. Los días 24 y 25 de noviembre del 2016, en Montevideo tuvo lugar un encuentro de capacitación en cuidados respiratorios no invasivos con más de 200 profesionales médicos, kinesiólogos y licenciadas de enfermería, destacando los avances y experiencia consolidad por el Dr. John Bach en más de 30 años de ejercicio profesional en pacientes con síndromes de hipoventilación secundario a enfermedades neuromusculares y otras condiciones que debilitan la bomba respiratoria. Las recomendaciones claves se resumen en este articulo, destacando como estos avances requieren impulsar un cambio de paradigma en la forma en que los profesionales de la salud ven y tratan a estos individuos.

Estudios de sueño en pacientes con enfermedades neuromusculares / Sleep breathing disorders in children with neuromuscular diseases

Sleep disordered breathing (SDB) is frencuent en pediatric patients with neuromuscular diseases, generated by different should be conduced early and with a preset frecuency, even more if there is the clinical suspicion of SDB and respiratory function imparment. There are different diagnostic studies, each with its advantages and disadvantages. Polysomnography is considered the reference standard and alternatively, pólygraphy has shown a high level of correlation with respiratory events

Los trastornos respiratorios del sueño (TRS) son frecuentes en los pacientes pediátricos con enfermedades neuromusculares, siendo generados por diversos mecanismos fisiopatológicos que usualmente llevan a hipoventilación y síndrome de apnea hipopnea obstructiva del sueño. la indicación de estudio debe ser precoz y con una periocidad prestablecida, más aún frente a la sospecha clínica del TRS y al constatar alteraciones funcionales respiratorias. Existen disitintos estudios para su diagnóstico y seguimiento, incluso en pacientes con soporte ventilatorio no invasivo; cadas uno con ventajas e inconvenientes particulares. Destaca la polisomnografía, como estándar de referencia y como alternativa, la poligrafía que ha demostrado tener un alto índice de correlación con eventos respiratorios

Hipoventilación / Hypoventilation

Es frecuente encontrar el mal uso del vocablo hipoventilación pretendiendo expresar el hallazgo clínico de la disminución de los ruidos respitatorios. Este uso es inaceptable, ya que este término no se refiere a un signo de la semiología pulmonar sino a un trastorno de la fisiología respiratoria en que diversas situaciones patológicas conducen a hipoventilación alveolar, la que se confirma mediante la gasimetría arterial (aumento de la PaCO2 y disminución de la PaO2.

Decrease in spectral entropy by low tidal volume ventilation-associated severe hypercapnia: a case report / 대한마취과학회지

Severe hypercapnia can be predicted by a decrease in cerebral electrical activity. The authors describe a sudden decrease in spectral entropy due to severe hypercapnia-induced respiratory acidosis in a patient with chronic pulmonary obstructive disease during lung resection. After two and a half hours of low tidal volume ventilation in the lateral position, the state entropy suddenly dropped from 45 to 7, without any changes in the effect-site concentration of propofol, end-tidal carbon dioxide (CO₂) tension, oxygen saturation, or arterial pressure. However, arterial blood gas analysis showed severe respiratory acidosis (pH 7.01, PaCO₂ 115 mmHg and PaO₂ 246 mmHg with FIO₂ of 0.5). Immediate hyperventilation improved the state entropy and acid-base balance. Electroencephalography-based spectral entropy can detect severe hypercapnia in chronic pulmonary obstructive disease patients with a large arterial to end-tidal CO2 difference due to prolonged hypoventilation during thoracic surgery.

Decrease in spectral entropy by low tidal volume ventilation-associated severe hypercapnia: a case report / 대한마취과학회지

Severe hypercapnia can be predicted by a decrease in cerebral electrical activity. The authors describe a sudden decrease in spectral entropy due to severe hypercapnia-induced respiratory acidosis in a patient with chronic pulmonary obstructive disease during lung resection. After two and a half hours of low tidal volume ventilation in the lateral position, the state entropy suddenly dropped from 45 to 7, without any changes in the effect-site concentration of propofol, end-tidal carbon dioxide (CO₂) tension, oxygen saturation, or arterial pressure. However, arterial blood gas analysis showed severe respiratory acidosis (pH 7.01, PaCO₂ 115 mmHg and PaO₂ 246 mmHg with FIO₂ of 0.5). Immediate hyperventilation improved the state entropy and acid-base balance. Electroencephalography-based spectral entropy can detect severe hypercapnia in chronic pulmonary obstructive disease patients with a large arterial to end-tidal CO2 difference due to prolonged hypoventilation during thoracic surgery.

Two Cases of Pediatric Obstructive Hypoventilation Managed with Upper Airway Surgery

Sleep-disordered breathing in children can include habitual snoring, obstructive hypoventilation, upper airway resistance syndrome, and obstructive sleep apnea. Obstructive hypoventilation in children is characterized by CO₂ retention caused by prolonged partial upper airway obstruction during sleep. To date, there have been few studies regarding the clinical significance and management strategies in pediatric obstructive hypoventilation, although it is a unique feature of pediatric sleep-disordered breathing. In this report, we describe two cases of obstructive hypoventilation that demonstrated improvement following upper airway surgery. These results suggest that upper airway surgery could be an additional treatment modality in obstructive hypoventilation.

Anti-N-methyl-D-aspartate Receptor (NMDAR) Encephalitis: Neuronal Burden of a Comorbid Ovarian Teratoma

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a disease that is characterized by acute psychiatric symptoms, seizures, and central hypoventilation. Patients with anti-NMDAR encephalitis exhibit speech alterations, insomnia, seizures, and movement disorders. We describe a previously healthy 6-year-old girl who presented with seizures, disorientation, and fever. Over the five weeks of treatment, the patient exhibited progressive neurologic symptoms, including a change in mental status. Her serum and cerebrospinal fluid contained high titers of antibodies against the NMDAR, and she was diagnosed with anti-NMDAR encephalitis. She was treated with plasmapheresis, steroid pulse therapy, intravenous immunoglobulins, and repeated doses of rituximab. After the patient was diagnosed with a concomitant ovarian teratoma, a unilateral salpingo-oophorectomy was performed. A histopathologic examination revealed that neuronal elements accounted for 60% of the resected ovarian teratoma. The patient's clinical symptoms and antibody titers improved after the surgical treatment and rituximab therapy. These observations suggested that patients with high titers of anti-NMDAR antibodies should be examined for the presence and quantity of neuronal components in concurrent ovarian teratomas.