The occurrence of delayed neuropsychologic sequelae in acute carbon monoxide poisoning patients after treatment with hyperbaric or normobaric oxygen therapy.

ABSTRACT: This study aimed at assessing which one of the 2 therapies is better for treating carbon monoxide (CO) poisoning from the perspective of reducing delayed neuropsychologic sequelae (DNS).We used Taiwan's National Health Insurance Research Database (NHIRD) to conduct a nationwide population-based cohort study to assess which therapy is better for CO poisoning patients. To accurately identify patients with DNS, the definition of DNS is included neurological sequelae, and cognitive and psychological sequele. The independent variable was therapy and the dependent variable was DNS occurred within 1 year after discharge from a medical institution. The control variables were age, gender, the severity of CO poisoning, and comorbidities present before CO poisoning admission.The risk of developing DNS in patients treated with Hyperbaric Oxygen (HBO) was 1.87-fold (P < .001) than normobaric oxygen (NBO) therapy. The severity of CO poisoning and comorbidities were also found to have significant influences on the risk of developing DNS.HBO may be a risk therapy for treating CO poisoning.

COVID-19 challenge for modern medicine.

Coronaviruses cause disease in animals and people around the world. Human coronaviruses (HCoV) are mainly known to cause infections of the upper and lower respiratory tract but the symptoms may also involve the nervous and digestive systems. Since the beginning of December 2019, there has been an epidemic of SARS-CoV-2, which was originally referred to as 2019-nCoV. The most common symptoms are fever and cough, fatigue, sputum production, dyspnea, myalgia, arthralgia or sore throat, headache, nausea, vomiting or diarrhea (30%). The best prevention is to avoid exposure. In addition, contact per-sons should be subjected to mandatory quarantine. COVID-19 patients should be treated in specialist centers. A significant number of patients with pneumonia require passive oxygen therapy. Non-invasive ventilation and high-flow nasal oxygen therapy can be applied in mild and moderate non-hypercapnia cases. A lung-saving ventilation strategy must be implemented in acute respiratory distress syndrome and mechanically ventilated patients. Extracorporeal membrane oxygenation is a highly specialized method, available only in selected centers and not applicable to a significant number of cases. Specific pharmacological treatment for COVID-19 is not currently available. Modern medicine is gearing up to fight the new coronavirus pandemic. The key is a holistic approach to the patient including, primar-ily, the use of personal protective equipment to reduce the risk of further virus transmission, as well as patient management, which consists in both quarantine and, in the absence of specific pharmacological therapy, symptomatic treatment.

Improving oxygen therapy for children and neonates in secondary hospitals in Nigeria: study protocol for a stepped-wedge cluster randomised trial.

BACKGROUND: Oxygen is a life-saving, essential medicine that is important for the treatment of many common childhood conditions. Improved oxygen systems can reduce childhood pneumonia mortality substantially. However, providing oxygen to children is challenging, especially in small hospitals with weak infrastructure and low human resource capacity. METHODS/DESIGN: This trial will evaluate the implementation of improved oxygen systems at secondary-level hospitals in southwest Nigeria. The improved oxygen system includes: a standardised equipment package; training of clinical and technical staff; infrastructure support (including improved power supply); and quality improvement activities such as supportive supervision. Phase 1 will involve the introduction of pulse oximetry alone; phase 2 will involve the introduction of the full, improved oxygen system package. We have based the intervention design on a theory-based analysis of previous oxygen projects, and used quality improvement principles, evidence-based teaching methods, and behaviour-change strategies. We are using a stepped-wedge cluster randomised design with participating hospitals randomised to receive an improved oxygen system at 4-month steps (three hospitals per step). Our mixed-methods evaluation will evaluate effectiveness, impact, sustainability, process and fidelity. Our primary outcome measures are childhood pneumonia case fatality rate and inpatient neonatal mortality rate. Secondary outcome measures include a range of clinical, quality of care, technical, and health systems outcomes. The planned study duration is from 2015 to 2018. DISCUSSION: Our study will provide quality evidence on the effectiveness of improved oxygen systems, and how to better implement and scale-up oxygen systems in resource-limited settings. Our results should have important implications for policy-makers, hospital administrators, and child health organisations in Africa and globally. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12617000341325 . Retrospectively registered on 6 March 2017.

Therapeutic potential of soluble guanylate cyclase modulators in neonatal chronic lung disease.

Supplemental oxygen after premature birth results in aberrant airway, alveolar, and pulmonary vascular development with an increased risk for bronchopulmonary dysplasia, and development of wheeze and asthma, pulmonary hypertension, and chronic obstructive pulmonary disease in survivors. Although stimulation of the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cGMP signal transduction pathway has significant beneficial effects on disease development in animal models, so far this could not be translated to the clinic. Oxidative stress reduces the NO-sGC-cGMP pathway by oxidizing heme-bound sGC, resulting in inactivation or degradation of sGC. Reduced sGC activity and/or expression is associated with pathology due to premature birth, oxidative stress-induced lung injury, including impaired alveolar maturation, smooth muscle cell (SMC) proliferation and contraction, impaired airway relaxation and vasodilation, inflammation, pulmonary hypertension, right ventricular hypertrophy, and an aggravated response toward hyperoxia-induced neonatal lung injury. Recently, Britt et al. (10) demonstrated that histamine-induced Ca(2+) responses were significantly elevated in hyperoxia-exposed fetal human airway SMCs compared with normoxic controls and that this hyperoxia-induced increase in the response was strongly reduced by NO-independent stimulation and activation of sGC. These recent studies highlight the therapeutic potential of sGC modulators in the treatment of preterm infants for respiratory distress with supplemental oxygen. Such treatment is aimed at improving aberrant alveolar and vascular development of the neonatal lung and preventing the development of wheezing and asthma in survivors of premature birth. In addition, these studies highlight the suitability of fetal human airway SMCs as a translational model for pathological airway changes in the neonate.

[Oxidative stress after preterm birth: origins, biomarkers, and possible therapeutic approaches]. / Stress oxydant chez l'enfant prématuré : causes, biomarqueurs et possibilités thérapeutiques.

The survival of preterm babies has increased over the last few decades. However, disorders associated with preterm birth, known as oxygen radical diseases of neonatology, such as retinopathy, bronchopulmonary dysplasia, periventricular leukomalacia, and necrotizing enterocolitis are severe complications related to oxidative stress, which can be defined by an imbalance between oxidative reactive species production and antioxidant defenses. Oxidative stress causes lipid, protein, and DNA damage. Preterm infants have decreased antioxidant defenses in response to oxidative challenges, because the physiologic increase of antioxidant capacity occurs at the end of gestation in preparation for the transition to extrauterine life. Therefore, preterm infants are more sensitive to neonatal oxidative stress, notably when supplemental oxygen is being delivered. Furthermore, despite recent advances in the management of neonatal respiratory distress syndrome, controversies persist concerning the oxygenation saturation targets that should be used in caring for preterm babies. Identification of adequate biomarkers of oxidative stress in preterm infants such as 8-iso-prostaglandin F2α, and adduction of malondialdehyde to hemoglobin is important to promote specific therapeutic approaches. At present, no therapeutic strategy has been validated as prevention or treatment against oxidative stress. Breastfeeding should be considered as the main measure to improve the antioxidant status of preterm infants. In the last few years, melatonin has emerged as a protective molecule against oxidative stress, with antioxidant and free-radical scavenger roles, in experimental and preliminary human studies, giving hope that it can be used in preterm infants in the near future.

Evaluation of risk factors for retinopathy in preterm infant: a case-control study in a referral hospital in Iran.

AIM: Aim of the study was to detect possible risk factors for retinopathy of prematurity (ROP), as a leading cause of treatable childhood blindness, among premature neonates. METHODS: In this retrospective study, 60 premature neonates with ROP and 60 premature infants without ROP were entered and compared. Variables such as gestational age, birth weight, oxygen therapy, phototherapy, and so on were gathered and compared between the two groups. RESULTS: Significant statistical differences were seen regarding gestational age (29.3±3.1 weeks in the ROP group vs. 31.9±2.2 in control group) and first-minute apgar score (6.55±1.7 in the ROP group vs. 7.06±2.3 in the control group). Regarding comparisons made in terms of therapeutic interventions made, only oxygen therapy and phototherapy showed significant differences between the two groups which were higher in the ROP group. CONCLUSION: Gestational age (lower in the ROP group), first-minute Apgar score (lower mean score in the ROP group), birth weight, phototherapy, and oxygen therapy were factors discovered to affect the occurrence of ROP among premature infants. Higher birth weight and more advanced gestational age were protective factors for ROP. Oxygen therapy and multiple birth are ROP risk factors and these can be used for prediction of ROP occurrence.

Assessment of health status and program performance in patients on long-term oxygen therapy.

BACKGROUND: Despite well established clinical guidelines, performance of long-term oxygen therapy (LTOT) programs shows marked variability among territories. The current study assessed the LTOT program and the health status of patients on LTOT prior to the deployment of community-based integrated care in an urban health district of Barcelona (Spain). AIMS: To assess: i) the LTOT program and health status of the patients on LTOT in the health district; ii) their frailty profile; and, iii) the requirements for effective deployment of integrated care services for these patients. METHODS: Cross-sectional observational study design including all patients (n = 406) on LTOT living in the health district. Health status, frailty, arterial blood gases, forced spirometry and hand-grip muscle strength were measured. Network analysis of frailty was carried out. RESULTS: Adequacy of LTOT prescription (n = 362): 47% and 31% of the patients had PaO2 ≤ 60 mmHg and ≤55 mmHg, respectively. Adherence to LTOT: 31% of all patients used LTOT ≥15 h/d; this figure increased to 67% in those with PaO2≤60 mmHg. Assessment of frailty: Overall, LTOT patients presented moderate to severe frailty. Care complexity was observed in 42% of the patients. CONCLUSIONS: Adequacy and adherence to LTOT was poor and many patients were frail and complex. The outcomes of the network analysis may contribute to enhance assessment of frailty in LTOT patients. These observations suggest that an integrated care strategy has the potential to improve the health outcomes of these patients.

Normobaric hyperoxia is associated with increased cerebral excitotoxicity after severe traumatic brain injury.

BACKGROUND: Normobaric oxygen therapy is frequently applied in neurocritical care, however, whether supplemental FiO2 has beneficial cerebral effects is still controversial. We examined in patients with severe traumatic brain injury (TBI) the effect of incremental FiO2 on cerebral excitotoxicity, quantified by cerebral microdialysis (CMD) glutamate. METHODS: This was a retrospective analysis of a database of severe TBI patients monitored with CMD and brain tissue oxygen (PbtO2). The relationship of FiO2--categorized into four separate ranges (<40, 41-60, 61-80, and >80 %)--with CMD glutamate was examined using ANOVA with Tukey's post hoc test. RESULTS: A total of 1,130 CMD samples from 36 patients--monitored for a median of 4 days--were examined. After adjusting for brain (PbtO2, intracranial pressure, cerebral perfusion pressure, lactate/pyruvate ratio, Marshall CT score) and systemic (PaCO2, PaO2, hemoglobin, APACHE score) covariates, high FiO2 was associated with a progressive increase in CMD glutamate [8.8 (95 % confidence interval 7.4-10.2) µmol/L at FiO2 < 40 % vs. 12.8 (10.9-14.7) µmol/L at 41-60 % FiO2, 19.3 (15.6-23) µmol/L at 61-80 % FiO2, and 22.6 (16.7-28.5) µmol/L at FiO2 > 80 %; multivariate-adjusted p < 0.05]. The threshold of FiO2-related increase in CMD glutamate was lower for samples with normal versus low PbtO2 < 20 mmHg (FiO2 > 40 % vs. FiO2 > 60 %). Hyperoxia (PaO2 > 150 mmHg) was also associated with increased CMD glutamate (adjusted p < 0.001). CONCLUSIONS: Incremental normobaric FiO2 levels were associated with increased cerebral excitotoxicity in patients with severe TBI, independent from PbtO2 and other important cerebral and systemic determinants. These data suggest that supra-normal oxygen may aggravate secondary brain damage after severe TBI.

Anton syndrome during oxygen-ozone therapy.

Ozone (O3) gas is a molecule that consists of 3 oxygen atoms, found out in the mid-19th century [1]. Ozone gas preserves humans from detrimental influences of ultraviolet radiation [1]. In spite of harmful effects of O3 gas, investigators think that it has excessive curative effects [1]. Nowadays, O3 therapy is used for many fields of medicine in precise therapeutic doses [1] and [2]. It is known that O3 therapy is helpful in dental procedures, cerebrovascular diseases, tinnitus, acquired immunodeficiency syndrome, hypercholesterolemia, sensorial hypoacusis, senile dementia, multiple sclerosis, irradiation sensitive tumors, herpes simplex and herpes zoster virus infections, muscular hypertonia, and chronic otitis media, etc.[2]. The complications and disadvantages of O3 therapy could be observed in the future. Herein, we presented a case of ischemic stroke after an oxygen-O3 therapy, which is called also Anton syndrome.

Advances in the therapy of hyperoxia-induced lung injury: findings from animal models.

Oxygen therapy is one of the most widely used clinical interventions to counteract insufficient pulmonary oxygen delivery in patients with severe lung injury. However, prolonged exposure to hyperoxia at elevated partial pressure leads to inflammation and acute lung injury. The population at risk for this condition has markedly increased with the advent of efficient systems for delivery of high concentrations of oxygen in hospitals. Thus, the therapy of hyperoxia-induced lung injury has been a focus in studies of pediatrics and pulmonary medicine. In this paper, we briefly summarized the advances in the therapies of hyperoxia-induced lung injury on the basis of its pathogenesis. We hope our summary will help provide evidence for further investigation of therapeutic measures for hyperoxia-induced lung injury.

Early postnatal additional high-dose oral vitamin A supplementation versus placebo for 28 days for preventing bronchopulmonary dysplasia or death in extremely low birth weight infants.

BACKGROUND: Prematurity and the associated risk for bronchopulmonary dysplasia (BPD) remain a significant threat to extremely low birth weight (ELBW) infants. Vitamin A has been considered a therapeutic alternative in reducing the rate of BPD and mortality. OBJECTIVES: To investigate whether early postnatal, additional high-dose oral vitamin A supplementation for 28 days is more efficient in reducing BPD or death in ELBW infants than placebo treatment. METHODS: This is a multicenter, double-blind RCT comparing postnatal high-dose oral vitamin A supplementation (5,000 IU vitamin A/kg/day vs. placebo) for 28 days in ELBW neonates requiring mechanical ventilation, noninvasive ventilatory support or supplemental oxygen at 24 h of age. The primary end point is the proportion of children who died before 36 weeks' gestational age or developed moderate or severe BPD. BPD is defined as the need for supplemental oxygen to maintain SaO2 of ≥92% at rest at 36 weeks' postmenstrual age (PMA). Clinical secondary end points include the following: BPD (including mild form), intraventricular hemorrhage, periventricular leukomalacia, retinopathy of prematurity, necrotizing enterocolitis, total number of days of mechanical ventilation and oxygen supplementation, and safety and tolerability of high-dose vitamin A supplementation. RESULTS AND CONCLUSIONS: The results of the NeoVitaA trial will provide robust data with regard to the efficacy of high-dose oral vitamin A supplementation in reducing the incidence of BPD or death at 36 weeks' PMA in ELBW infants.

Protective Effects of Nigella sativa Oil in Hyperoxia-Induced Lung Injury.

BACKGROUND: Oxygen-induced lung injury is believed to lead to the development of bronchopulmonary dysplasia in premature infants. We have evaluated the beneficial effects of Nigella sativa oil (NSO) on rats with hyperoxia-induced lung injury. METHODS: Thirty newborn Sprague-Dawley rats were randomly divided into 3 groups as hyperoxia (95% O(2)), hyperoxia+NSO and control (21% O(2)). Pups in the hyperoxia+NSO group were administered intraperitoneal NSO at a dose of 4ml/kg daily during the study period. Histopathologic, immunochemical, and biochemical evaluations (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], malonaldehyde [MDA] and myeloperoxidase [MPO]) were performed. RESULTS: In the histopathologic and immunochemical evaluation, severity of lung damage was significantly lower in the hyperoxia+NOS group (P<.05). Tissue GSH-Px and SOD levels were significantly preserved, and MDA, MPO levels were significantly lower in the hyperoxia+NSO group (P<.05). CONCLUSION: NSO significantly reduced the severity of lung damage due to hyperoxia.

Rational use of oxygen in medical disease and anesthesia.

PURPOSE OF REVIEW: Supplemental oxygen is often administered during anesthesia and in critical illness to treat hypoxia, but high oxygen concentrations are also given for a number of other reasons such as prevention of surgical site infection (SSI). The decision to use supplemental oxygen is, however, controversial, because of large heterogeneity in the reported results and emerging reports of side-effects. The aim of this article is to review the recent findings regarding benefits and harms of oxygen therapy in anesthesia and acute medical conditions. RECENT FINDINGS: Large randomized trials have not found significant reductions in SSI with 80% oxygen during and after abdominal surgery and cesarean section. There is no documented benefit of hyperbaric oxygen treatment for acute ischemic stroke, and there is emerging data to suggest increased mortality with normobaric supplemental oxygen for myocardial infarction without heart failure. Survival and neurologic outcome seem to be adversely affected by hyperoxia in patients with return of spontaneous circulation after cardiac arrest. SUMMARY: The benefits of supplemental oxygen are not yet confirmed, and new findings suggest that potential side-effects should be considered if the inspired oxygen concentration is increased above what is needed to maintain normal arterial oxygen saturation.

Melatonin ameliorates necrotizing enterocolitis in a neonatal rat model.

INTRODUCTION: We designed the present study to evaluate the efficacy of melatonin (M) on the severity of necrotizing enterocolitis (NEC) in a neonatal rat model. MATERIALS AND METHODS: Immediately after birth, pups were weighed and randomized into 3 groups: NEC, NEC + M, and control. Necrotizing enterocolitis was induced by enteral formula feeding and exposure to hypoxia after cold stress at 4°C and oxygen. The NEC + M group received 10 mg/kg M daily for 3 days after the first day of the NEC procedure. The pups were killed on the fourth day, and their intestinal tissues were harvested for biochemical and histopathologic analysis. Blood samples were also obtained from the pups. RESULTS: The mortality rate and weight loss were highest in the NEC group. Malondialdehyde and protein carbonyl content were significantly increased, whereas superoxide dismutase and glutathione peroxidase were decreased in the NEC-treated pups. Melatonin prevented these changes, with these values being similar to control levels in the NEC + M group. Nitrate plus nitrite levels and serum tumor necrosis factor α and interleukin-1ß were increased in the NEC group, and histopathologic injury score in the NEC group was significantly higher than that in the NEC + M group. CONCLUSION: Melatonin significantly reduced the severity of NEC in our study.

Recurrent wheezing in the third year of life among children born at 32 weeks' gestation or later: relationship to laboratory-confirmed, medically attended infection with respiratory syncytial virus during the first year of life.

OBJECTIVE: To quantify the relationship between recurrent wheezing (RW) in the third year of life and respiratory syncytial virus (RSV) infection, prematurity, and neonatal oxygen exposure. DESIGN: Retrospective cohort study linking inpatient, outpatient, and laboratory databases for cohort assembly and logistic regression analysis. SETTING: Integrated health care delivery system in Northern California. PARTICIPANTS: A total of 71,102 children born from 1996 to 2002 at 32 weeks' gestational age or later who were health plan members for 9 or more months in their first and third years. MAIN EXPOSURES: Laboratory-confirmed, medically attended RSV infection during first year and supplemental oxygen during birth hospitalization. OUTCOME MEASURES: Recurrent wheezing, quantified through outpatient visits, inpatient hospital stays, and asthma prescriptions. RESULTS: The rate of RW in the third year of life was 16.23% among premature infants with RSV and 6.22% among those without RSV. The risk of RW increased among infants who had an RSV outpatient encounter (adjusted odds ratio [AOR], 2.07; 95% CI, 1.61-2.67), uncomplicated RSV hospitalization (AOR, 4.66; 95% CI, 3.55-6.12), or prolonged RSV hospitalization (AOR, 3.42; 95% CI, 2.01-5.82) compared with infants without RSV encounters. Gestational age of 34 to 36 weeks was associated with increased risk of RW (AOR, 1.23; 95% CI 1.07-1.41) compared with 38 to 40 weeks, while a gestational age of 41 weeks or more was protective (AOR, 0.90; 95% CI, 0.81-0.99). Supplemental oxygen exposure was associated with increased risk at all levels. CONCLUSION: Laboratory-confirmed, medically attended RSV infection, prematurity, and exposure to supplemental oxygen during the neonatal period have independent associations with the development of RW in the third year of life.

Normobaric hyperoxia therapy for traumatic brain injury and stroke: a review.

Traumatic brain injury (TBI) and acute ischaemic stroke are major causes of mortality and morbidity and there is an urgent demand for new neuroprotective strategies following the translational failure of neuroprotective drug trials. Oxygen therapy--especially normobaric, may offer a simple and effective therapeutic strategy which we review in this paper. Firstly we review mechanisms underlying the therapeutic effects of hyperoxia (both normobaric and hyperbaric) including mitochondrial rescue, stabilisation of intracranial pressure, attenuation of cortical spreading depression and inducing favourable endothelial-leukocyte interactions, all effects of which are postulated to decrease secondary injury. Next we survey studies using hyperbaric oxygen therapy for TBI and stroke, which formed the basis for early studies on normobaric hyperoxia. Thirdly, we present clinical studies of the efficacy of normobaric hyperoxia on TBI and stroke, emphasising their safety, efficacy and practicality. Finally we consider safety concerns and side effects, particularly pulmonary pathology, respiratory failure and theoretical risks in paediatric patients. A neuroprotective role of normobaric hyperoxia is extremely promising and further studies are warranted.

Oxygen therapy-use and abuse in acute myocardial infarction patients.

In August 2008, an article was published in Heart entitled, "The Routine Use of Oxygen in the Treatment of Myocardial Infarction." This article stimulated me to opine on this topic, which has been an interest of mine for many years.

Perivascular nitric oxide and superoxide in neonatal cerebral hypoxia-ischemia.

Decreased cerebral blood flow (CBF) has been observed following the resuscitation from neonatal hypoxic-ischemic injury, but its mechanism is not known. We address the hypothesis that reduced CBF is due to a change in nitric oxide (NO) and superoxide anion O(2)(-) balance secondary to endothelial NO synthase (eNOS) uncoupling with vascular injury. Wistar rats (7 day old) were subjected to cerebral hypoxia-ischemia by unilateral carotid occlusion under isoflurane anesthesia followed by hypoxia with hyperoxic or normoxic resuscitation. Expired CO(2) was determined during the period of hyperoxic or normoxic resuscitation. Laser-Doppler flowmetry was used with isoflurane anesthesia to monitor CBF, and cerebral perivascular NO and O(2)(-) were determined using fluorescent dyes with fluorescence microscopy. The effect of tetrahydrobiopterin supplementation on each of these measurements and the effect of apocynin and N(omega)-nitro-L-arginine methyl ester (L-NAME) administration on NO and O(2)(-) were determined. As a result, CBF in the ischemic cortex declined following the onset of resuscitation with 100% O(2) (hyperoxic resuscitation) but not room air (normoxic resuscitation). Expired CO(2) was decreased at the onset of resuscitation, but recovery was the same in normoxic and hyperoxic resuscitated groups. Perivascular NO-induced fluorescence intensity declined, and O(2)(-)-induced fluorescence increased in the ischemic cortex after hyperoxic resuscitation up to 24 h postischemia. L-NAME treatment reduced O(2)(-) relative to the nonischemic cortex. Apocynin treatment increased NO and reduced O(2)(-) relative to the nonischemic cortex. The administration of tetrahydrobiopterin following the injury increased perivascular NO, reduced perivascular O(2)(-), and increased CBF during hyperoxic resuscitation. These results demonstrate that reduced CBF follows hyperoxic resuscitation but not normoxic resuscitation after neonatal hypoxic-ischemic injury, accompanied by a reduction in perivascular production of NO and an increase in O(2)(-). The finding that tetrahydrobiopterin, apocynin, and L-NAME normalized radical production suggests that the uncoupling of perivascular NOS, probably eNOS, due to acquired relative tetrahydrobiopterin deficiency occurs after neonatal hypoxic-ischemic brain injury. It appears that both NOS uncoupling and the activation of NADPH oxidase participate in the changes of reactive oxygen concentrations seen in cerebral hypoxic-ischemic injury.