Search results for "hypoxemia"

Nail fold capillary diameter changes in acute systemic hypoxia.

2013

The present study was undertaken to determine the effect of arterial blood hypoxemia induced by acute systemic hypoxia (pO2=12%) on capillary recruitment and diameter, and red blood cell (RBC) velocity in human nail fold capillaries during rest, arterial post-occlusive reactive hyperemia (PRH), and venous occlusion (VO) using intravital video-capillaroscopy. Capillary recruitment was unchanged in acute systemic hypoxia (H) versus normoxia (N). There was no difference in RBC velocity measurements between normoxia and hypoxia (P<0.63). However, a statistically significant increase in nail fold capillary total width (N, 39.9±9.1 vs. H, 42.7±10.3 μm; P<0.05), apical diameter (N, 15.5±4.3 vs. H,…

Hypoxemia during Sleep

1988

In most normal subjects arterial oxyhemoglobin saturation (SaO2) remains substantially stable throughout all sleep time: some exceptions however, may be observed especially in elderly subjects, who may show desaturations, sometimes associated with apneas (Block et al., 1979; Krieger et al., 1983; Catterall et al., 1985). Conversely, SaO2 drops during part of, or even the whole sleep time, are a common finding in pathological conditions like obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD).

Patent Foramen Ovale and Thromboembolic Complications

2010

The foramen ovale, an atrial septal defect which is essential in the fetal circulation, remains patent through adulthood in approximately 25% of the general population and so it represents the most common persistent abnormality of fetal origin. Patent foramen ovale (PFO) allows interatrial right-to-left blood shunting during those periods of the cardiac cycle in which the right atrial pressure exceeds the left one. An increasing number of pathological manifestations of PFO has been recently identified; among these, paradoxical systemic embolism, refractory hypoxemia in patients with right ventricular myocardium infarction or severe pulmonary disease, orthostatic oxygen desaturation in the r…

Muscle Oxygen Delivery in the Forearm and in the Vastus Lateralis Muscles in Response to Resistance Exercise: A Comparison Between Nepalese Porters a…

2020

Altitude ascending represents an intriguing experimental model reproducing physiological and pathophysiological conditions sharing hypoxemia as the denominator. The aim of the present study was to investigate fractional oxygen extraction and blood dynamics in response to hypobaric hypoxia and to acute resistance exercises, taking into account several factors including different ethnic origin and muscle groups. As part of the “Kanchenjunga Exploration &amp; Physiology” project, six Italian trekkers and six Nepalese porters took part in a high altitude trek in the Himalayas. The measurements were carried out at low (1,450 m) and high altitude (HA; 4,780 m). Near-infrared spectroscopy (NIRS)-d…

Acetazolamide treatment for infantile central sleep apnea.

2001

Central sleep apnea is a common respiratory pattern in healthy neonates. Nevertheless, frequent central sleep apnea associated with drops in oxygen saturation may contribute to infantile morbidity. Recently, low-dose acetazolamide was shown to reduce symptomatic central sleep apnea in adults. We treated 12 infants, median conceptional age 42 weeks (range, 40-44 weeks), with central sleep apnea. In all cases, the central apnea index was &gt;40/h total sleeping time (apnea ≥ 3 sec). The cumulative duration of drops in oxygen saturation below 90% was more than 3 min/h total sleeping time. All individuals received acetazolamide 7 mg/kg/day (orally, divided in three doses) for 11 weeks. Polysomn…

Exercise Effects on Erythrocyte Deformability in Exercise-induced Arterial Hypoxemia

2014

Exercise-induced arterial hypoxemia (EIAH) is often found in endurance-trained subjects at high exercise intensity. The role of erythrocyte deformability (ED) in EIAH has been scarcely explored. We aimed to explore the role of erythrocyte properties and lactate accumulation in the response of ED in EIAH. ED was determined in 10 sedentary and in 16 trained subjects, both before and after a maximal incremental test, and after recovery, along with mean corpuscular volume (MCV) and red blood cell lactate concentrations. EIAH was found in 6 trained subjects (∆SaO2=-8.25±4.03%). Sedentary and non-EIAH trained subjects showed reduced ED after exercise, while no effect on ED was found in EIAH train…

Is it possible to predict which patients with mild pneumonias will develop hypoxemia?

2009

SummaryUsually, mortality due to mild community-acquired pneumonias (CAP) (Pneumonia severity index (PSI) classes I–III) is low (<3%), but the appearance of hypoxemia significantly increases mortality. Our aim was to determine the clinical parameters associated with risk factors of developing hypoxemia in subjects with mild CAP (PSI I–III) and the clinical outcomes of the hypoxemic group.We analyzed clinical characteristics and the outcomes of patients with mild CAP and hypoxemia (PaO2/FiO2<300), in a prospective, multicenter cohort study of 1195 patients.Mild pneumonias (PSI I–III) were found in 645 cases (53.9%), of which 217 (33.6%) presented hypoxemia according to a PaO2/FiO2<300. Patie…

Noninvasive Ventilation in Critically Ill Patients

2015

Since its first application in the late 1980s, noninvasive ventilation (NIV) has been the first-line intervention for certain forms of acute respiratory failure. NIV may be delivered through the patient's mouth, nose, or both using noninvasive intermittent positive pressure ventilation or continuous positive airway pressure. When applied appropriately, NIV may reduce morbidity and mortality and may avert iatrogenic complications and infections associated with invasive mechanical ventilation. This article provides physicians and respiratory therapists with a comprehensive, practical guideline for using NIV in critical care. © 2015 Elsevier Inc.

Metabolic effects of hypoxia and sleep at high altitude(5050)

2010

Normal Values of Oxygen Concentration in Human Blood

1984

Under physiological conditions, the oxygen supply as the product of O2-concentration (mlO2/dl; %(v/v)) and perfusion is influenced by many factors (cf. Fig. 1): perfusion on one hand, oxygen partial pressure (pO2; mmHg), haemoglobin (Hb) concentration (g/dl) and O2 binding power of Hb on the other hand. Under pathological conditions, oxygen supply disturbances are related to hypoxemia, i.e. reduction of O2-concentration in the blood. The differential diagnosis of hypoxemia includes normoxic, hypoxic and circulatoric disturbances of oxygen supply (cf. Fig. 1). Thus it is necessary to describe a NORMOXIC HYPOXEMIA (anemic or toxemic), a HYPOXIC HYPOXEMIA (decreased O2-concentration caused by …