1.
Hypoxia in Obesity and Diabetes: Potential Therapeutic Effects of Hyperoxia and Nitrate.
Norouzirad, R, González-Muniesa, P, Ghasemi, A
Oxidative medicine and cellular longevity. 2017;:5350267
Abstract
The prevalence of obesity and diabetes is increasing worldwide. Obesity and diabetes are associated with oxidative stress, inflammation, endothelial dysfunction, insulin resistance, and glucose intolerance. Obesity, a chronic hypoxic state that is associated with decreased nitric oxide (NO) bioavailability, is one of the main causes of type 2 diabetes. The hypoxia-inducible factor-1α (HIF-1α) is involved in the regulation of several genes of the metabolic pathways including proinflammatory adipokines, endothelial NO synthase (eNOS), and insulin signaling components. It seems that adipose tissue hypoxia and NO-dependent vascular and cellular dysfunctions are responsible for other consequences linked to obesity-related disorders. Although hyperoxia could reverse hypoxic-related disorders, it increases the production of reactive oxygen species (ROS) and decreases the production of NO. Nitrate can restore NO depletion and has antioxidant properties, and recent data support the beneficial effects of nitrate therapy in obesity and diabetes. Although it seems reasonable to combine hyperoxia and nitrate treatments for managing obesity/diabetes, the combined effects have not been investigated yet. This review discusses some aspects of tissue oxygenation and the potential effects of hyperoxia and nitrate interventions on obesity/diabetes management. It can be proposed that concomitant use of hyperoxia and nitrate is justified for managing obesity and diabetes.
2.
Oxygen Saturation Targets for Extremely Preterm Infants after the NeOProM Trials.
Stenson, BJ
Neonatology. 2016;(4):352-8
Abstract
Five randomized controlled trials comparing lower (85-89%) versus higher (91-95%) pulse oximeter saturation (SpO2) targets for extremely preterm infants have now been reported from the United States of America, Canada, the United Kingdom, Australia and New Zealand. These trials included more than 4,800 infants, and they provide robust evidence to permit comparison of these target ranges and consider the next steps for clinicians and researchers. The lower SpO2 range was associated with a significant increase in the risk of death. There was no significant difference between the two target ranges in the rate of disability at 18-24 months, including blindness. A significant difference between groups in the risk of the composite primary outcome of death or disability in favour of the higher SpO2 range was mainly attributable to the difference between groups in the risk of death. The lower target range did not reduce bronchopulmonary dysplasia or severe visual impairment, but it did increase the risk of necrotizing enterocolitis requiring surgery or causing death. The trials provide no reason to prefer SpO2 targets below 90% and indicate the importance of more trials to see if a further survival advantage can be identified. The safety of targets above 95% has not been evaluated. The five trials were designed to be similar to facilitate an individual patient data meta-analysis, and this Neonatal Oxygen Prospective Meta-Analysis (NeOProM) may provide further insights.
3.
Oxygen saturation limits and evidence supporting the targets.
Newnam, KM
Advances in neonatal care : official journal of the National Association of Neonatal Nurses. 2014;(6):403-9
Abstract
Supplemental oxygen use in the preterm infant is required for survival. Evidence supports a narrow therapeutic window between the helpful and harmful effects of supplemental oxygen in this vulnerable population. The clinical question was-what are the recommended oxygen saturation targets for the preterm infant and the preterm infant corrected to term? Multiple databases were searched for published research in English from 2008 to 2014 using key search terms. A total of 18 articles met inclusion criteria. Early neonatal research linked high levels of supplemental oxygen with retinopathy of prematurity and blindness. Years later, correlations between high arterial oxygen levels and oxidative stress leading to pulmonary and/or neurologic insults were established. Three large multicentered, international studies have recently been published (BOOST II, COT, and SUPPORT), which support oxygen saturation target ranges of 87% to 94% until vascular maturation of the retina is achieved. Two of the 3 studies reported a significant correlation between low saturation limits (85%-89%) and death in the extremely preterm population. Identified best care strategies to prevent states of hypoxia and/or hyperoxia include establishing clear target saturation limits according to recommendations, which are supported by the multidisciplinary team, adequate nurse to patient ratio, improve knowledge deficits, improve bedside compliance, and finally visual cues to remind caregivers of target saturation ranges.
4.
Automated adjustments of inspired fraction of oxygen to avoid hypoxemia and hyperoxemia in neonates - a systematic review on clinical studies.
Hummler, H, Fuchs, H, Schmid, M
Klinische Padiatrie. 2014;(4):204-10
Abstract
Supplemental oxygen is commonly provided during transition of neonates immediately after birth. Whereas an initial FiO2 of 0.21 is now recommended to stabilize full-term infants in the delivery room, the best FiO2 to start resuscitation of the very low birth weight infant (VLBWI) immediately after delivery is currently not known. Recent recommendations include the use of pulse oximetry to titrate the use of supplemental oxygen. As reference values for pulse oximetry during the first minutes of life have become available, automated FiO2-adjustments are feasible and may be very useful for delivery room care to limit oxygen exposure. Beyond neonatal transition, preterm infants in the neonatal intensive care unit (NICU) commonly require supplemental oxygen to avoid hypoxemia, especially VLBWI receiving respiratory support because of poor respiratory drive and/or lung disease. For respiratory care of newborn infants in the NICU automated FiO2-adjustment systems have been developed and have been studied in preterm infants for limited time frames using short-term physiological outcomes. These studies could demonstrate short-term benefits such as more stable arterial oxygen saturation. Recent clinical trials have shown that oxygen targeting may significantly affect mortality and morbidity. Therefore, randomized controlled trials are needed to study the effects of automated FiO2-adjustment on long-term outcomes to prove possible benefits on survival, the rate of retino-pathy of prematurity and on neuro-development-al outcome.