Hyperoxia in very preterm infants: A systematic review of the literature
ABSTRACT Supplemental oxygen plays a critical role in the management of infants born at the lower limit of viability, but not without the risk of complications resulting from high levels or prolonged exposure. Longitudinal studies of very premature infants, born at less than 28 weeks' gestation, establish a clear relationship between pulse oximetry saturation readings above 92%, or hyperoxia, and development of severe retinopathy of prematurity, chronic lung disease, and brain injury. Hyperoxia is neither natural nor random. It is an unintended consequence of intervention. A comprehensive review of the literature reveals a strong association between exposure to hyperoxia and subsequent expression of comorbidities. Owing to this knowledge, eradication of hyperoxia, and consequent reduction of sequelae, is a significant public health concern that deserves attention by the neonatal community. Although prospective, collaborative meta-analyses will soon provide needed additional data to inform practice, existing compelling evidence supports urgent practice change to reduce exposure to hyperoxia in very preterm infants.
- SourceAvailable from: Mohamed N Ahmed[Show abstract] [Hide abstract]
ABSTRACT: Oxygen may damage the lung directly via generation of reactive oxygen species (ROS) or indirectly via the recruitment of inflammatory cells, especially neutrophils. Overexpression of extracellular superoxide dismutase (EC-SOD) has been shown to protect the lung against hyperoxia in the newborn mouse model. The CXC-chemokine receptor antagonist (Antileukinate) successfully inhibits neutrophil influx into the lung following a variety of pulmonary insults. In this study, we tested the hypothesis that the combined strategy of overexpression of EC-SOD and inhibiting neutrophil influx would reduce the inflammatory response and oxidative stress in the lung after acute hyperoxic exposure more efficiently than either single intervention. Neonate transgenic (Tg) (with an extra copy of hEC-SOD) and wild type (WT) were exposed to acute hyperoxia (95% FiO2 for 7 days) and compared to matched room air groups. Inflammatory markers (myeloperoxidase, albumin, number of inflammatory cells), oxidative markers (8-isoprostane, ratio of reduced/oxidized glutathione), and histopathology were examined in groups exposed to room air or hyperoxia. During the exposure, some mice received a daily intraperitoneal injection of Antileukinate. Antileukinate-treated Tg mice had significantly decreased pulmonary inflammation and oxidative stress compared to Antileukinate-treated WT mice (p < 0.05) or Antileukinate-non-treated Tg mice (p < 0.05). Combined strategy of EC-SOD and neutrophil influx blockade may have a therapeutic benefit in protecting the lung against acute hyperoxic injury.Respiratory research 07/2012; 13(1):58. DOI:10.1186/1465-9921-13-58 · 3.38 Impact Factor
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ABSTRACT: OBJECTIVE To determine whether birth and care in the highest-level hospitals (level III) compared with birth in or postnatal transfer to lower-level hospitals (level II) are associated with 5-year morbidity in very preterm children. DESIGN A cohort study. SETTING Finland. PARTICIPANTS All surviving 5-year-old children born very preterm (gestational age <32 weeks or birth weight ≤1500 g) born in level II or level III hospitals (n = 2168) and full-term (gestational age, 37-42 weeks) children (n = 238 857) born from January 1, 2000, through December 31, 2004. MAIN OUTCOME MEASURES Diagnoses issued after the first discharge home and overrepresented in very preterm compared with full-term children. Diagnoses were analyzed between very preterm children (1) born and treated in level III hospitals (group III), (2) born in level III and transferred to lower-level hospitals (group III/II), and (3) born and treated in level II hospitals (group II). RESULTS Group III/II children had an increased incidence of retinal disorders (odds ratio, 2.43 [95% CI, 1.66-3.56]) and asthma (1.41 [1.09-1.81]) but fewer viral infections (0.75 [0.59-0.95]) compared with group III infants. The risks for epilepsy (odds ratio, 2.71 [95% CI, 1.29-5.70]) and hyperkinetic disorders (2.19 [1.13-4.25]) were higher among group II than among group III children. No statistically significant differences between the groups for the 14 other diagnoses were found. CONCLUSIONS The increased incidence of retinopathy and asthma among infants transferred from level III to lower-level hospitals calls for analysis of the differences in treatment practices between hospital levels.JAMA Pediatrics 11/2012; 167(1):1-7. DOI:10.1001/jamapediatrics.2013.415 · 4.25 Impact Factor
Article: The Oxygen Therapy.[Show abstract] [Hide abstract]
ABSTRACT: Oxygen (O2) is a vital element. Shortage of O2 results in deranged metabolism and important changes in vascular tone with opposite effects on the systemic and pulmonary circulation. During hypoxemia, oxidative stress exposes the organism to a sort of accelerated senescence as well as to several acute untoward effects. Thus, hypoxemia should be promptly recognized and treated, hopefully by measures tailored to the pathophysiological mechanisms underlying hypoxemia. However, O2 therapy remains the most common therapy of hypoxemia, but it must be carefully tailored to relieve hypoxemia without provoking hyperoxia or hypercarbia. Then, the individual response to O2 as well as changing needs of O2 during sleep or exercise must be evaluated to provide the best O2 therapy. Hyperoxia, the effect of overcorrection of hypoxia, can dramatically impact the health status and threaten the survival of the newborn and, through different mechanisms and effects, the adult. A thorough knowledge of the pathophysiological bases of hypoxemia and O2 storage and delivery devices is then mandatory to administer O2 therapy guaranteeing for optimal correction of hypoxemia and minimizing the risk of hyperoxia. Consistent with this aim also is a careful scrutiny of instruments and procedures for monitoring the individual response to O2 over time. Thus, at variance from classical pharmacological therapy, performing O2 therapy requires a vast array of clinical and technical competences. The optimal integration of these competences is needed to optimize O2 therapy on individual bases.Current Medicinal Chemistry 01/2013; DOI:10.2174/0929867311320090002 · 3.85 Impact Factor