The interaction of breath holding and muscle mechanoreflex on cardiovascular responses in breath-hold divers and non-breath-hold divers.

Cardiovascular responses to diving are characterized by two opposing responses: tachycardia resulting from exercise and bradycardia resulting from the apnea. The convergence of bradycardia and tachycardia may determine the cardiovascular responses to diving. The purpose of this study was to investigate the interaction of breath holding and muscle mechanoreflex on cardiovascular responses in breath-hold divers (BHDs) and non-BHDs. We compared the cardiovascular responses to combined apnea and the mechanoreflex in BHDs and non-BHDs. All participants undertook three trials-apnea, passive leg cycling (PLC), and combined trials-for 30 s after rest. Cardiovascular variables were measured continuously. Nine BHD (male:female, 4:5; [means ± SD] age, 35 ± 6 years; height, 168.6 ± 4.6 cm; body mass, 58.4 ± 5.9 kg) and eight non-BHD (male:female, 4:4; [means ± SD] age, 35 ± 7 years; height, 163.9 ± 9.1 cm; body mass, 55.6 ± 7.2 kg) participants were included. Compared to the resting baseline, heart rate (HR) and cardiac output (CO) significantly decreased during the combined trial in the BHD group, while they significantly increased during the combined trials in the non-BHD group (P < 0.05). Changes in the HR and CO were significantly lower in the BHD group than in the non-BHD group in the combined trial (P < 0.05). These results suggest that bradycardia with apnea in BHDs is prioritized over tachycardia with the mechanoreflex, whereas that in non-BHDs is not. This finding implies that diving training changes the interaction between apnea and the mechanoreflex in cardiovascular control.

Recuperando el "hilo perdido" en la madeja de la enterocolitis necrotizante del recién nacido / Recovering the "lost thread" in the skein of necrotizing enterocolitis of the newborn / Recuperando o "fio perdido" no novelo de enterocolite necrosante do recém-nascido

Propósito de la revisión: el objetivo de la revisión es delinear la fisiopatología de la Entero Colitis Necrotizante (ECN) clásica del recién nacido, proponer un listado de antecedentes perinatales que definan un grupo de riesgo y establecer parámetros simples y objetivos, que ayuden a establecer un diagnóstico clínico precoz. Recientes hallazgos: La mortalidad de la Entero Colitis Necrotizante clásica del recién nacido sigue siendo elevada. Aunque la enfermedad tiene varias presentaciones, es única con una única vía de instalación, la hipoperfusión intestinal como agente agresor inicial. Extracto: La falta de estrategias de prevención y el diagnóstico clínico muy tardío explican la mortalidad elevada de la ECN. Existe una gran confusión sobre el origen de la enferme-dad, dando a entender que existen diferentes tipos de ECN, aunque la enfermedad es única, tiene diferentes manifestaciones según las condiciones del recién nacido con una vía común de instalación, la hipoperfusión intestinal como agente agresor inicial. En este artículo se postula que reconocer a la hipoperfusión intestinal como agente agresor inicial, es "encontrar el hilo perdido", que permitirá desarrollar estrategias de prevención y tratamiento, al identificar los pacientes en riesgo de ECN y lograr el diagnóstico de manera precoz.

Purpose of the review: The objective of the review is to delineate the pathophysiology of the classic Entero Necrotizing Colitis (NEC) of the newborn, propose a list of perinatal ante-cedents that define a risk group and establish simple and objective parameters that help to establish an early clinical diagnosis. Recent findings: The mortality of the classic Necrotizing Entero Colitis of the newborn is still high. Although the disease has several presentations, it is unique with a single installation route, intestinal hypoperfusion as the initial offending agent. Excerpt: The lack of prevention strategies and very late clinical diagnosis explain the high mortality of NEC. There is great confusion about the origin of the disease, giving to under-stand that there are different types of NEC, although the disease is unique, it has different manifestations according to the conditions of the newborn with a common route of installation, intestinal hypoperfusion as an initial assailant agent. This article postulates that recog-nizing intestinal hypoperfusion as the initial offending agent is "finding the lost thread", that developing prevention and treatment strategies, by identifying patients at risk of NEC and achieving a diagnosis in a way early.

Objetivo da revisão: O objetivo da revisão é delinear a fisiopatologia da Entero Colite Necrosante (NEC) clássica do recém-nascido, propor uma lista de antecedentes perinatais que definem um grupo de risco e estabelecer parâmetros simples e objetivos que auxiliem no diagnóstico clínico precoce. Descobertas recentes: A mortalidade da Entero Colite Necrosante clássica do recém-nascido ainda é alta. Embora a doença tenha várias apresentações, é única com uma única via de instalação, a hipoperfusão intestinal como agente agressor inicial. Resumo: A falta de estratégias de prevenção e o diagnóstico clínico muito tardio explicam a alta mortalidade da NEC. Há grande confusão sobre a origem da doença, sugerindo que existem diferentes tipos de NEC, embora a doença seja única, ela tem diferentes manifestações dependendo das condições do recém-nascido com uma via comum de instalação, a hipoperfusão intestinal como agente. assaltante inicial. Este artigo postula que reconhecer a hipoperfusão intestinal como agente agressor inicial é "encontrar o fio condutor", o que permitirá o desenvolvimento de estratégias de prevenção e tratamento, por meio da identificação de pacientes em risco de NEC e do diagnóstico precoce.