Initial Use of 100% but Not 60% or 30% Oxygen Achieved a Target Heart Rate of 100 bpm and Preductal Saturations of 80% Faster in a Bradycardic Preterm Model.

Background: Currently, 21−30% supplemental oxygen is recommended during resuscitation of preterm neonates. Recent studies have shown that 58% of infants < 32 week gestation age are born with a heart rate (HR) < 100 bpm. Prolonged bradycardia with the inability to achieve a preductal saturation (SpO2) of 80% by 5 min is associated with mortality and morbidity in preterm infants. The optimal oxygen concentration that enables the achievement of a HR ≥ 100 bpm and SpO2 of ≥80% by 5 min in preterm lambs is not known. Methods: Preterm ovine model (125−127 d, gestation equivalent to human neonates < 28 weeks) was instrumented, and asphyxia was induced by umbilical cord occlusion until bradycardia. Ventilation was initiated with 30% (OX30), 60% (OX60), and 100% (OX100) for the first 2 min and titrated proportionately to the difference from the recommended preductal SpO2. Our primary outcome was the incidence of the composite of HR ≥ 100 bpm and SpO2 ≥ 80%, by 5 min. Secondary outcomes were to evaluate the time taken to achieve the primary outcome, gas exchange, pulmonary/systemic hemodynamics, and the oxidative injury. Results: Eighteen lambs (OX30-6, OX60-5. OX100-7) had an average HR < 91 bpm with a pH of <6.92 before resuscitation. Sixty seven percent achieved the primary outcome in OX100, 40% in OX60, and none in OX30. The time taken to achieve the primary outcome was significantly shorter with OX100 (6 ± 2 min) than with OX30 (10 ± 3 min) (* p = 0.04). The preductal SpO2 was highest with OX100, while the peak pulmonary blood flow was lowest with OX30, with no difference in O2 delivery to the brain or oxidative injury by 10 min. Conclusions: The use of 30%, 60%, and 100% supplemental O2 in a bradycardic preterm ovine model did not demonstrate a significant difference in the composite primary outcome. The current recommendation to use 30% oxygen did not achieve a preductal SpO2 of 80% by 5 min in any preterm lambs. Clinical studies to optimize supplemental O2 in depressed preterm neonates not requiring chest compressions are warranted.

Resuscitation with an Intact Cord Enhances Pulmonary Vasodilation and Ventilation with Reduction in Systemic Oxygen Exposure and Oxygen Load in an Asphyxiated Preterm Ovine Model.

(1) Background: Optimal initial oxygen (O2) concentration in preterm neonates is controversial. Our objectives were to compare the effect of delayed cord clamping with ventilation (DCCV) to early cord clamping followed by ventilation (ECCV) on O2 exposure, gas exchange, and hemodynamics in an asphyxiated preterm ovine model. (2) Methods: Asphyxiated preterm lambs (127-128 d) with heart rate <90 bpm were randomly assigned to DCCV or ECCV. In DCCV, positive pressure ventilation (PPV) was initiated with 30-60% O2 and titrated based on preductal saturations (SpO2) with an intact cord for 5 min, followed by clamping. In ECCV, the cord was clamped, and PPV was initiated. (3) Results: Fifteen asphyxiated preterm lambs were randomized to DCCV (N = 7) or ECCV (N = 8). The inspired O2 (40 ± 20% vs. 60 ± 20%, p < 0.05) and oxygen load (520 (IQR 414-530) vs. 775 (IQR 623-868), p-0.03) in the DCCV group were significantly lower than ECCV. Arterial oxygenation and carbon dioxide (PaCO2) levels were significantly lower and peak pulmonary blood flow was higher with DCCV. (4) Conclusion: In asphyxiated preterm lambs, resuscitation with an intact cord decreased O2 exposure load improved ventilation with an increase in peak pulmonary blood flow in the first 5 min.

Síndrome metabólico en individuos de una comunidad rural / Metabolic syndrome in individuals in a rural community

Objetivo: caracterizar el síndrome metabólico (SM) en un medio rural venezolano. Contexto y tipo de estudio: la frecuencia de SM es elevada en el mundo y es elemento de riesgo en el desarrollo de diabetes mellitus y enfermedad cardiovascular, pero existe limitada información sobre SM en las zonas rurales de la mayoría de los países. Se realizó un estudio descriptivo y transversal en un sector rural del estado Cojedes, Venezuela. Material y método: fueron 39 los sujetos con edades entre 20-59 años, 51.3% mujeres y 56.4% tenían antecedentes familiares de riesgo cardiometabólico. Se definió según el Tercer Reporte del Panel de Expertos del Programa Nacional de Educación (NCEP/ATPIII), como SM a la presencia de por lo menos tres de los cinco factores siguientes: obesidad abdominal (> 88 cm en mujeres y de 102 cm en hombres) hiperglicemia en ayunas (> 110 mg/dL), hipertensión arterial (> 130/85 mmHg), lipoproteína de alta densidad (HDL-c) (< 50 mg/dL) y triglicéridos elevados (> 150 mg/dL). Resultados: la prevalencia de SM fue 20.5%, 12.8% hombres y 7.7% mujeres, el criterio diagnóstico predominante fue la hipertrigliceridemia (53.8%) y las mujeres con SM eran más hipertensas, hiperglicémicas, con menos HDL-c, mayor concentración de triglicéridos y obesas que los hombres. Conclusión: el SM afecta por igual al medio rural y urbano, pero en Venezuela la prevalencia es mayor en la región urbana llanera. El género masculino es también el más afectado y la diabetes mellitus e HTA son los antecedentes familiares más frecuentes. La obesidad abdominal e hipertrigliceridemia los factores de riesgo SM más señalados. Se infiere adopción rural de hábitos alimentarios urbanos. (Acta Med Colomb 2012; 37: 177-182).

Objective: to characterize the metabolic syndrome (MS) in a rural Venezuelan environment. Context and Type of Study: MS has a high frequency worldwide and is a risk factor in the development of diabetes mellitus and cardiovascular disease, but the information about SM in these areas is limited. We performed a cross-sectional descriptive study in a rural sector in Cojedes state, Venezuela. Methods: we studied 39 subjects aged 20-59 years. 51.3% female and 56.4% had a family history of cardiometabolic risk. According to the Third Report of the Expert Panel of the National Education Program (NCEP / ATPIII), SM was defined as the presence of at least three of the following five factors: abdominal obesity (> 88 cm in women and 102 cm in men) fasting hyperglycemia (> 110 mg / dL), hypertension (> 130/85 mmHg), high density lipoprotein (HDL-C) (<50 mg / dL) and triglycerides (> 150 mg / dL). Results: the prevalence of MS was 20.5% (12.8% men and 7.7% women). The predominant diagnostic criteria was hypertriglyceridemia (53.8%) and women with MS were more hypertensive, hyperglycemic, with less HDL-C, higher triglycerides, and were more obese than men. Conclusion: MS equally affects both rural and urban areas, but in Venezuela the prevalence is higher in urban plains. Male gender is also the most affected and diabetes mellitus and hypertension are the most frequent family history. Abdominal obesity and hypertriglyceridemia are the most signaled SM risk factors. It infers the rural adoption of urban food habits. (Acta Med Colomb 2012; 37: 177-182).