Normoblastemia multinuclear en un recién nacido secundaria a hipoxia / Multinucleated normoblastemia in a newborn secondary to hypoxia

Es posible detectar normoblastos en los frotis de sangre periférica de los recién nacidos. En general, la cantidad de normoblastos por cada 100 leucocitos está en el intervalo de 0 a 10. Se observan con más frecuencia de lo usual ante una situación de hipoxia porque la hipoxia intrauterina aumenta la producción de eritrocitos. Sin embargo, no se había informado antes un caso de normoblastos multinucleados en un recién nacido a causa de la hipoxia. Presentamos el caso de un recién nacido con normoblastos multinucleados secundarios a hipoxia intrauterina. Este caso es importante porque es la primera vez que se han detectado normoblastos multinucleados en el frotis de sangre periférica de un recién nacido hipóxico.

Normoblasts may be seen in peripheral blood smear of newborns. The number of normoblasts per 100 white blood cells is generally in the range of 0-10.They can be seen more common than usual in hypoxic condition, because intrauterine hypoxia increases the production of red blood cells. However, multinucleated normoblasts in a newborn caused by hypoxia haven't been reported before. We present a newborn with multinucleated normoblasts secondary to intrauterine hypoxia. This case is important; because it is the first time multinucleated normoblasts in peripheral blood smear of a hypoxic newborn has been detected.

Evaluation of intranasal oxygen supplementation in mules anesthetized with the combination of ketamine, butorphanol, and guaifenesin / Avaliação da suplementação intranasal de oxigênio em muares anestesiados com a associação de cetamina, butorfanol e éter gliceril guaiacólico

Hypoxemia is a major complication of field anesthesia and no studies regarding this occurrence in mules has been done. Thus, the aim of this study was to evaluate intranasal oxygen supplementation (IOS) in mules (Equus caballus x Equus asinus) anesthetized with ketamine/butorphanol/guaifenesin combination. For this, we used six male, adult mules (322±29kg) which underwent premedication (MPA) with 0.2mg/kg of midazolam intramuscularly after 15 minutes, 0.02mg/kg detomidine IV 5 minutes after, induction IV with combination of ketamine (2mg/mL), butorphanol (22.5mg/mL), and guaifenesin (50mg/mL) (K/B/G) until lateral decumbency. Maintenance was done with the same anesthetic combination. The animals were submitted twice to the protocol described above, 20 days apart, forming two groups. CG: MPA, induction (0.92±0.24mL/kg (mean±SD)), and maintenance (2.2±0.2mL/kg/h) without SIO; TG: MPA, induction (0.98±0.17mL/kg), and maintenance (2.3±0.4mL/kg/h) with IOS flow 40mL/kg/h. During anesthesia arterial blood was collected every 20 minutes (T0, T20, T40, and T60) for blood gas analysis. Data analyzed by ANOVA followed by the Bonferroni test. P<0.05 was considered significant. Hypoxemia of the animals in the CG in periods (59±5; 55±5; 53±7; 49±8) with lower averages than the TG (160±4, 115±34, 92±25, 81±19) was observed, demonstrating that IOS increases PaO2 avoiding the occurrence of hypoxemia.(AU)

A hipoxemia é uma das principais complicações da anestesia a campo, e em muares não existem estudos a respeito dessa ocorrência. Assim, objetivou-se avaliar a suplementação intranasal de oxigênio (SIO) em muares (Equus caballus x Equus asinus) anestesiados com cetamina/butorfanol/guaifenesina associados. Para isso, foram utilizados seis muares, macho e adultos (322±29kg), submetidos à medicação pré-anestésica (MPA) com 0,2mg/kg de midazolam por via intramuscular, após 15 minutos, 0,02mg/kg de detomidina por via intravenosa, após cinco minutos, indução com administração intravenosa da associação de cetamina (2mg/mL), butorfanol (22,5 µg/mL) e guaifenesina (50mg/mL) em solução de glicose a 5% (C/B/G) até o animal assumir o decúbito lateral. A manutenção foi realizada com a mesma associação anestésica. Os animais foram submetidos duas vezes ao protocolo descrito anteriormente, com intervalo de 20 dias, formando dois grupos experimentais. GC -MPA, indução (0,92±0,24mL/kg (média±DP)) e manutenção (2,2±0,2mL/kg/h) sem SIO; GT - MPA, indução (0,98±0,17mL/kg) e manutenção (2,3±0,4mL/kg/h) com SIO, fluxo de 40mL/kg/h. Durante a anestesia, foi colhido sangue arterial a cada 20 minutos (T0, T20, T40 e T60) para hemogasometria. Os dados foram analisados pela ANOVA, seguidos pelo teste de Bonferroni. Valores de P<0,05 foram considerados significativos. Foi observada hipoxemia (PaO2<60mmHg) dos animais no GC nos tempos avaliados (T0= 59±5; T20= 55±5; T40= 53±7; T60= 49±8), com médias menores que as do GT, (160±4; 115±34; 92±25; 81±19, respectivamente), o que demonstrou que a suplementação intranasal de oxigênio aumenta a PaO2, evitando a ocorrência de hipoxemia.

Inflammation induced by increased frequency of intermittent hypoxia is attenuated by tempol administration

The levels of serum inflammatory cytokines and the activation of nuclear factor kappa B (NF-κB) and hypoxia inducible factor-1α (HIF-1α) in heart tissues in response to different frequencies of intermittent hypoxia (IH) and the antioxidant tempol were evaluated. Wistar rats (64 males, 200-220 g) were randomly divided into 6 experimental groups and 2 control groups. Four groups were exposed to IH 10, 20, 30, or 40 times/h. The other 2 experimental groups were challenged with IH (30 times/h) plus tempol, either beginning on day 0 (IH30T0) or on day 29 (IH30T29). After 6 weeks of challenge, serum levels of tumor necrosis factor (TNF)-α, intracellular adhesion molecule (ICAM)-1, and interleukin-10 were measured, and western blot analysis was used to detect NF-κB p65 and HIF-1α in myocardial tissues. Serum levels of TNF-α and ICAM-1 and myocardial expression of NF-κB p65 and HIF-1α were all significantly higher in IH rats than in controls (P<0.001). Increased IH frequency resulted in more significant changes. Administration of tempol in IH rats significantly reduced levels of TNF-α, ICAM-1, NF-κB and HIF-1α compared with the non-tempol-treated group (F=16.936, P<0.001). IH induced an inflammatory response in a frequency-dependent manner. Additionally, HIF-1α and NF-κB were increased following IH administration. Importantly, tempol treatment attenuated this effect.

Melatonin prevents hyperglycemia in a model of sleep apnea

Objective Obstructive sleep apnea is a common disorder associated with aging and obesity. Apneas cause repeated arousals, intermittent hypoxia, and oxidative stress. Changes in glucolipidic profile occur in apnea patients, independently of obesity. Animal models of sleep apnea induce hyperglycemia. This study aims to evaluate the effect of the antioxidants melatonin and N-acetylcysteine on glucose, triglyceride, and cholesterol levels in animals exposed to intermittent hypoxia. Materials and methods Two groups of Balb/c mice were exposed to intermittent hypoxia (n = 36) or sham intermittent hypoxia (n = 36) for 35 days. The intermittent hypoxia group underwent a total of 480 cycles of 30 seconds reducing the inspired oxygen fraction from 21% to 7 ± 1% followed by 30 seconds of normoxia, during 8 hours daily. Melatonin or N-acetylcysteine were injected intraperitonially daily from day 21 on. Results At day 35, glucose levels were significantly higher in the intermittent hypoxia group than in the control group. The intermittent hypoxia groups receiving N-acetylcysteine and vehicle showed higher glucose levels than the group receiving melatonin. The lipid profile was not affected by intermittent hypoxia or antioxidant administration. Conclusions The present results suggest that melatonin prevents the well-recognized increase in glucose levels that usually follows exposure to intermittent hypoxia. Further exploration of the role of melatonin in sleep apnea is warranted. Arch Endocrinol Metab. 2015;59(1):66-70 .

Hypobaric hypoxia-mediated protein expression in plasma of susceptible & tolerant rats.

Background & objectives: Low availability of oxygen at high altitudes has a great impact on the human life processes. There is a widespread interest and need to find out protein(s) that are possibly involved in mediating tolerance to hypobaric hypoxia. We undertook this study to identify and characterize protein expression in plasma of hypoxia susceptible and tolerant rats. Methods: Male albino Sprague Dawley rats were segregated into susceptible and tolerant groups on the basis of their gasping time when exposed to simulated hypobaric hypoxia of 32,000 ft (9,754 m) at 32ºC. Comparative proteome profiling of blood plasma of hypoxia susceptible and tolerant individuals was performed using 2-dimentional (2-D) gel electrophoresis. Results: Three proteins with higher expression levels were selected separately from tolerant and susceptible samples. Characterization of these proteins from tolerant sample using MALDI-TOF/TOF and MASCOT search indicated their homology with two different super-families viz. NADB-Rossmann superfamily (Rab GDP dissociation inhibitor β) and Transferrin superfamily (two Serotransferrins), having potential role in imparting tolerance against hypoxia. Three high level upregulated proteins were characterized from blood plasma of hypoxia susceptible animals showing similarity with threonine tRNA ligase (mitochondrial), carbohydrate sulphotransferase 7 and aspartate tRNA ligase (cytoplasmic) that play a role in ATP binding, carbohydrate metabolism and protein biosynthesis, respectively. Interpretation & conclusions: Our results indicated that rats segregated into hypoxia sensitive and tolerant based on their gasping time showed differential expression of proteins in blood plasma. Characterization of these differentially expressed proteins will lead to better understanding of molecular responses occurring during hypoxia and subsequently development of biomarkers for categorization of hypoxia susceptible and tolerant individuals.

Hypoxia among patients on the liver-transplant waiting list / Hipoxia entre os pacientes na lista de espera para transplante de figado

Background: Hepatopulmonary syndrome is formed by a triad of liver disease, intrapulmonary vascular dilatation and changes in blood gases. This condition is present in 4-32% of patients with cirrhosis. Aim : To analyze the blood gas changes data of patients in liver-transplant waiting list. Method: Clinical data of 279 patients in liver transplantation waiting list in May 2013 were studied. Overall patient was analyzed by the demographic aspects, laboratorial and image findings on exams that determine lung disease (hypoxemia) in these cirrhotic patients. The mean values and standard deviations were used to examine normally distributed variables. Results: There was a high prevalence of male patients (68%); the mean age was 51(±5,89) years, and the predominant reason for listing was hepatitis C cirrhosis. The MELD score mean was 16±5,89, without prioritization or special situation. The most common blood type was O in 129 cases (46%) and the mean of body max index was 25,94±4,58. Regarding arterial blood gas tests was observed 214 patients with PaO2 <90 mmHg, 80 with PaO2 <80 mmHg and 39 with PaO2 <50 mmHg. In relation to O2 saturation, 50 patients had <90%, 33 <80% and 10 <50%. Conclusion: Was observed a high rate of hypoxemia in patients on waiting list liver transplant. Due to the high severity and morbidity, is suggested better monitoring and therapeutic support to hypoxemic patients on liver transplant waiting list. .

Racional: A síndrome hepatopulmonar é formada por tríade clínica com doença do fígado, dilatação vascular intrapulmonar e alterações nos gases sanguíneos. Esta condição está presente em 4-32% dos pacientes com cirrose. Objetivo : Analisar as alterações gasométricas nos pacientes em lista de espera de transplante de fígado. Método: Foram estudados dados clínicos de 279 pacientes na lista de espera para transplante hepático em maio de 2013. Foram analisados aspectos demográficos, gasometria arterial e achados de imagem que determinam a doença pulmonar (hipoxemia) nestes pacientes cirróticos. Os valores médios e desvios-padrão foram utilizados para examinar as variáveis ​​normalmente distribuídas. Resultados: Houve alta prevalência de homens (68%); a idade média foi de 51 (±5,89) anos; e a razão predominante para listar para o transplante foi cirrose pelo vírus C. O MELD médio foi de 16±5,89, sem priorização ou situação especial. O tipo de sangue mais comum foi O, 129 casos (46%) e a média do índice de massa corporal foi 25,94±4,58. Com relação aos exames de gasometria arterial, observou-se 214 pacientes com PaO2 <90 mmHg, 80 com PaO2 <80 mmHg e 39 com PaO2 <50 mmHg, e em relação à saturação de O2, 50 pacientes <90%, 33 pacientes <80% e 10 pacientes <50%. Conclusão: Observou-se alta taxa de hipoxemia nos pacientes em lista de transplante de fígado; devido à elevada gravidade e morbidade, sugere-se melhor seguimento e suporte terapêutico aos doentes hipoxêmicos na lista de espera para o transplante de fígado. .

Effects of different PEEP levels on respiratory mechanics and oxygenation after coronary artery bypass grafting / Efeitos de diferentes níveis de PEEP na mecânica respiratória e oxigenação após revascularização do miocárdio

OBJECTIVE: To compare the effects of different levels of positive end-expiratory pressure on respiratory mechanics and oxygenation indexes in the immediate postoperative period of coronary artery bypass grafting. METHODS: Randomized clinical trial in which 136 patients underwent coronary artery bypass grafting between January 2011 and March 2012 were divided into three groups and admitted to mechanical ventilation with different positive end-expiratory pressure levels: Group A, 5 cmH2O (n=44), Group B, 8 cmH2O (n=47) and Group C, 10 cmH2O (n=45). Data about respiratory mechanics were obtained from mechanical ventilator monitor and oxygenation indexes from arterial blood gas samples, collected twenty minutes after intensive care unit admission. Patients with chronic obstructive pulmonary disease and patients submitted to off-pump, emergency or combined operations were not included. For statistical analysis, we used Kruskal-Wallis, G and Chi-square tests, considering results significant when P<0.05. RESULTS: Groups were homogeneous in terms of demographic, clinical and surgical variables. Patients ventilated with positive end-expiratory pressure of 10 cmH2O (Group C) had best compliance (P=0.04) and airway resistance values, this, however, without statistical significance. They also had best oxygenation indexes, with statistical difference in all analyzed variables, and lower frequency of hypoxemia (P=0.03). CONCLUSION: Higher levels of positive end-expiratory pressure in immediate postoperative period of coronary artery bypass grafting improved pulmonary compliance values and increased oxygenation indexes, resulting in lower frequency of hypoxemia.

OBJETIVO: Comparar os efeitos de diferentes níveis de pressão expiratória positiva final na mecânica respiratória e nos índices de oxigenação no pós-operatório imediato de revascularização do miocárdio. MÉTODOS: Ensaio clínico randomizado no qual 136 pacientes submetidos à revascularização do miocárdio, entre janeiro de 2011 e março de 2012, foram distribuídos em três grupos e admitidos na ventilação mecânica com diferentes níveis de pressão expiratória positiva final: Grupo A, 5 cmH2O (n=44), Grupo B, 8 cmH2O (n=47) e Grupo C, 10 cmH2O (n=45), sendo os dados da mecânica respiratória obtidos do monitor do ventilador mecânico e os índices de oxigenação por meio de gasometria arterial coletada vinte minutos após a admissão na unidade de terapia intensiva. Não foram incluídos pacientes com doença pulmonar obstrutiva crônica, cirurgias associadas, de emergência ou sem circulação extracorpórea. Para análise estatística, empregaram-se os testes de Kruskal-Wallis, Teste G e Qui-quadrado, considerando os resultados significantes quando P<0,05. RESULTADOS: Os grupos apresentaram-se homogêneos em relação às variáveis demográficas, clínicas e cirúrgicas. Os pacientes ventilados com pressão expiratória positiva final de 10 cmH2O (Grupo C) apresentaram os melhores valores de complacência (P=0,04) e de resistência das vias aéreas, esta, porém sem significância estatística. Apresentaram, ainda, os melhores índices de oxigenação, com diferença estatística em todas as variáveis estudadas, além de menor frequência de hipoxemia (P=0,03). CONCLUSÃO: Níveis mais elevados de pressão expiratória positiva final no pós-operatório imediato de revascularização do miocárdio incrementaram os valores de complacência pulmonar e melhoraram os índices de oxigenação, resultando acarretando em menor frequência de hipoxemia.

Hipoxemia espuria por hiperleucocitosis: Reporte de un caso y revisión de la literatura / Spurious hypoxemia due to hyperleukocytosis: Report of one case

Background: Arterial gasometry is considered the gold standard for establishing a diagnosis of respiratory failure of any etiology. However, there are some circumstances in which it loses specificity, making necessary to consider other tests such as pulse oximetry to adequately determine hypoxemia. We report a 67 years old patient with sudden hypoacusia, right hemiparesis and polypnea. His laboratory exams on admission, showed extreme hypoxemia in several readings, without correlation to the patient's clinical condition nor the pulse oximetry, and a leukocytosis of 800.000 cells x ml, with many immature cells. Chronic myeloid leukemia was diagnosed and treatment with hydroxyurea was initiated, achieving normalization in the arterial gases in accordance with the fall of the white cell count. Interpretation of laboratory findings according to the general clinical context of the patient allowed to suspect a spurious hypoxemia, saving the patient from unnecessary and risky interventions.

MAPA em portadores de DPOC com dessaturação no sono / MAPA en portadores de EPOC con desaturación durante el sueño / ABPM in COPD patients with sleep desaturation

FUNDAMENTO: A hipoxemia no período de sono pode, por mecanismo de ativação simpática, alterar a pressão arterial. Poucos estudos demonstram os parâmetros pressóricos em portadores de DPOC, que não têm apnéia do sono, mas que dessaturam nesse período. OBJETIVOS: Analisar os parâmetros pressóricos em pacientes com DPOC e dessaturação no sono, não causada por apnéia. MÉTODOS: Treze pacientes com DPOC foram submetidos à espirometria, gasometria arterial, polissonografia e MAPA para avaliação pressórica. Quatorze pacientes sem DPOC foram submetidos à espirometria, oximetria e MAPA. As análises pressóricas foram feitas tanto na vigília quanto no sono. Os dois grupos foram constituídos por pacientes sem antecedentes hipertensivos. RESULTADOS: Os dois grupos eram semelhantes em relação à idade, altura, peso e índice de massa corporal. Houve diferença significativa (p < 0,05) entre os parâmetros pressóricos nos períodos de vigília, sono, 24 horas e descenso do sono. Observou-se valores pressóricos maiores nos portadores de DPOC, exceto em níveis diastólicos em vigília, máximos valores ao sono e nas 24 horas. O descenso do sono no grupo DPOC foi atenuado, enquanto no grupo controle foi fisiológico, com menores valores pressóricos. CONCLUSÕES: Os resultados da pressão arterial sistólica e diastólica se mostraram maiores no grupo DPOC do que no grupo controle. A significância dessa afirmação ocorreu em todos os períodos aferidos, exceto em vigília e nas 24 horas para níveis de pressão diastólica. Pode-se concluir que, o grupo portador de DPOC com dessaturação no sono possui níveis de pressão arterial significativamente maiores do que o grupo controle.

BACKGROUND: Sleep hypoxemia may change blood pressure by sympathetic activation. Few studies have analyzed blood pressure parameters in COPD patients who do not present sleep apnea, but do present sleep desaturation. OBJECTIVES: To analyze blood pressure parameters in COPD patients with sleep desaturation not caused by apnea. METHODS: Thirteen patients with COPD underwent spirometry, blood gas, polysomnography and ABPM for blood pressure evaluation. Fourteen patients without COPD underwent spirometry, oximetry and ABPM. Blood pressure analyses were carried out both during wakefulness and sleep. Both groups were comprised of patients with no history of hypertension. RESULTS: The two groups were similar as regards age, height, weight, and body mass index. A significant difference (p<0.05) was found between blood pressure levels during the wakefulness, sleep, 24-hour and sleep dip periods. Higher blood pressure levels were observed in patients with COPD, except for diastolic levels during wakefulness and maximum values during sleep and in the 24 hours. Sleep dip in the COPD group was attenuated, whereas physiological dip was observed in the control group, with lower blood pressure levels. CONCLUSIONS: Systolic and diastolic blood pressure levels in the COPD group were higher than those of the control group, with a significant difference found for all periods studied, except for diastolic levels during wakefulness and in the 24 hours. We can conclude that the group of COPD patients with sleep desaturation has significantly higher blood pressure levels than the control group.

FUNDAMENTO: La hipoxemia en el período de sueño puede, por mecanismo de activación simpática, alterar la presión arterial. Pocos estudios demuestran los parámetros de presión en portadores de EPOC, que no tiene apnea del sueño, y que desaturan en ese período. OBJETIVO: Analizar los parámetros de presión en pacientes con EPOC y desaturación en el sueño, no causada por apnea. MÉTODOS: Trece pacientes con EPOC se sometieron a la espirometría, la gasometría arterial, la polisonografía y al MAPA para la evaluación de presión. Un total de 14 pacientes sin EPOC se sometieron a la espirometría, la oximetría y MAPA. Los análisis de presión se hicieron tanto en la vigilia como en el sueño. Los dos grupos estaban conformados por pacientes sin antecedentes hipertensivos. RESULTADOS: Los dos grupos se asemejaban respecto a la edad, la altura, el peso e el índice de masa corporal. Hubo diferencia significativa (p < 0,05) entre los parámetros de presión en los períodos de vigilia, sueño, 24 horas y descenso del sueño. Se observaron valores de presión arterial mayores en los portadores de EPOC, a excepción de los niveles diastólicos en vigilia, máximos valores al sueño y en las 24 horas. El descenso del sueño en el grupo EPOC se halló atenuado, mientras que en el grupo control fue fisiológico, con menores valores de presión arterial. CONCLUSIÓN: Los resultados de la presión arterial sistólica y diastólica se hallaron mayores en el grupo EPOC que en el grupo control. La significancia de esa afirmación ocurrió en todos los períodos medidos, a excepción de la vigilia y en las 24 horas para niveles de presión diastólica. Se puede concluir que, el grupo portador de EPOC con desaturación en el sueño posee niveles de presión arterial significativamente mayores que en el grupo control.

Efeitos sistêmicos da hipoxemia noturna em pacientes com doença pulmonar obstrutiva crônica sem síndrome da apnéia obstrutiva do sono / Systemic effects of nocturnal hypoxemia in patients with chronic obstructive pulmonary disease without obstructive sleep apnea syndrome

OBJETIVO: Estudar os efeitos da hipoxemia noturna em pacientes com doença pulmonar obstrutiva crônica sem síndrome da apnéia obstrutiva do sono. MÉTODOS: Estudamos 21 pacientes-10 dessaturadores e 11 não-dessaturadores-submetidos a gasometria arterial, polissonografia, espirometria, teste de exercício cardiopulmonar (cicloergômetro), dinamometria manual e medidas de pressão inspiratória máxima, pressão expiratória máxima e proteína C reativa (PCR). Incluíram-se os pacientes com pressão parcial arterial de oxigênio > 60 mmHg; excluíram-se os com índice de apnéia-hipopnéia > 5 eventos/hora de sono. Foram medidos consumo máximo de oxigênio, potência máxima, pressão arterial sistólica, pressão arterial diastólica (PAD) e frequência cardíaca máxima durante exercício, visando detectar alterações hemodinâmicas. A PCR foi considerada positiva quando acima de 3 mg/L. RESULTADOS: A saturação periférica de oxigênio mínima durante o sono foi significativamente maior nos não-dessaturadores (p = 0,03). Mais dessaturadores apresentaram PCR > 3 mg/L (p < 0,05). Não houve diferença quanto a capacidade de exercício e demais variáveis. No entanto, PAD (p < 0,001) e pressão inspiratória máxima (p = 0,001) correlacionaram-se com saturação periférica de oxigênio média durante o sono. CONCLUSÕES: A hipoxemia noturna não reduz a capacidade de exercício e a força de preensao manual em pacientes com DPOC leve/moderada, mas o ajuste da PAD durante o exercício máximo parece depender do grau de hipoxemia. Além disso, há uma relação positiva entre pressão inspiratória máxima e saturação periférica de oxigênio média durante o sono, bem como indícios de ativação inflamatória diferenciada em pacientes com hipoxemia noturna.

OBJECTIVE: To study the effects of nocturnal hypoxemia in patients with chronic obstructive pulmonary disease without obstructive sleep apnea syndrome. METHODS: We studied 21 patients-10 desaturators and 11 nondesaturators-submitted to arterial blood gas analysis, polysomnography, spirometry, cardiopulmonary exercise testing (cycle ergometer), and hand-grip dynamometry, as well as measurements of maximal inspiratory pressure, maximal expiratory pressure, and C-reactive protein (CRP) levels. Patients with arterial oxygen tension > 60 mmHg were included; those with an apnea-hypopnea index > 5 events/hour of sleep were excluded. Maximal oxygen uptake, maximal power, systolic blood pressure, diastolic blood pressure (DBP), and maximal heart rate were measured during exercise in order to detect hemodynamic alterations. Patients presenting CRP levels above 3 mg/L were considered CRP-positive. RESULTS: Minimal peripheral oxygen saturation during sleep was significantly higher among nondesaturators (p = 0.03). More desaturators presented CRP > 3 mg/L (p < 0.05). No differences were observed in terms of any variables, However, mean peripheral oxygen saturation during sleep correlated with DBP and maximal inspiratory pressure (p < 0.001 and p = 0.001, respectively). CONCLUSIONS: Although nocturnal hypoxemia does not reduce exercise capacity or hand-grip strength in patients with mild/moderate COPD, its effect on maximal exercise DBP seems to depend on the degree of hypoxemia. In addition, there is a positive relationship between maximal inspiratory pressure and mean peripheral oxygen saturation during sleep, as well as evidence of pronounced inflammatory activation in patients with nocturnal hypoxemia.

Ion fluxes and hematological parameters of two teleosts from the Rio Negro, Amazon, exposed to hypoxia / Fluxos iônicos e parâmetros hematológicos em duas espécies de teleósteos do Rio Negro, Amazônia, expostos à hipoxia

The aim of this study was to describe the effect of hypoxia on whole body ion fluxes and hematological parameters in two Amazonian teleosts: Serrasalmus eigenmanni and Metynnis hypsauchen. The increase of Na+ and Cl- effluxes on M. hypsauchen exposed to hypoxia may be related to an increase of gill ventilation and effective respiratory surface area, to avoid a reduction in the oxygen uptake, and/or with the decrease of pHe, that could inhibit Na+ and Cl- transporters and, therefore, reduce influx of these ions. Effluxes of Na+ and Cl- were lower in hypoxia than in normoxia for S. eigenmanni, possibly because in hypoxia this species would reduce gill ventilation and oxygen uptake, which would lead to a decrease of gill ion efflux and, consequently, reducing ion loss. The increase on hematocrit (Ht) during hypoxia in M. hypsauchen probably was caused by an increase of the red blood cell volume (MCV). For S. eigenmanni the increase on glucose possibly results from the usage of glucose reserve mobilization. Metynnis hypsauchen showed to be more sensitive to hypoxia than Serrasalmus eigenmanni, since the first presented more significant alterations on these osmoregulatory and hematological parameters. Nevertheless, the alterations observed for both species are strategies adopted by fishes to preserve oxygen supply to metabolizing tissues during exposure to hypoxia.

O objetivo deste trabalho foi descrever o efeito da hipoxia no fluxo iônico corporal e nos parâmetros hematológicos em duas espécies de teleósteos da Amazônia: Serrasalmus eigenmanni e Metynnis hypsauchen. O aumento dos efluxos de Na+ e Cl- em M. hypsauchen expostos à hipoxia pode estar relacionado ao aumento da ventilação branquial e da eficiência da área da superfície respiratória, a fim de evitar redução na captação de oxigênio; e/ou com a diminuição do pHe, que pode inibir os transportadores de Na+ e Cl- e, então, reduzir o influxo destes íons. Os efluxos de Na+ e Cl- foram menores em hipoxia do que em normoxia para a espécie S. eigenmanni, possivelmente porque esta espécie em hipoxia poderia reduzir a ventilação branquial e a captação de oxigênio, a qual levaria a uma diminuição do efluxo branquial de íons e, conseqüentemente, à redução da perda de íons. O aumento do hematócrito (Ht) durante hipoxia em M. hypsauchen provavelmente foi causado pelo aumento do volume das células vermelhas do sangue (MCV). Para a espécie S. eigenmanni, o aumento da glicose possivelmente foi resultado do uso da mobilização da reserva de glicose. A espécie Metynnis hypsauchen mostrou ser mais sensível à hipoxia do que a espécie Serrasalmus eigenmanni, uma vez que a primeira espécie apresentou mais alterações significativas em seus parâmetros osmorregulatórios e hematológicos. Contudo, as alterações observadas em ambas as espécies são estratégias adotadas pelos peixes a fim de preservar o suprimento de oxigênio para metabolização nos tecidos durante exposição à hipoxia.

Desempeño aeróbico de futbolistas jóvenes en ejercicio sub-máximo con agotamiento a moderada altitud sin aclimatación: experiencia en el Cóndor / Young football players aerobic perfomance in sub-maximum exercise with exhaustion at a moderate altitude without acclimation: experience in El Condor

A igual intensidad de esfuerzo sub-máximo, la concentración de lactato sérico (LS) y muscular es mayor en condición de hipoxia o ejercicio en altitud sin aclimatación, respecto normoxia o nivel del mar. El pico de lactato tras la fatiga, o en prueba de codición anaeróbica estricta, no se modificaría con un cambio de altitud sin aclimatación previa. Objetivo: Obtener datos locales acerca de al magnitud del efecto de una altitud efectiva de 1.700 mts. sin aclimatación sobre LS, como parámetro de desempeño aeróbico, de futbolistas jóvenes de nuestro medio que viven y entrenan a nivel del mar (NM). Voluntarios y métodos: Ensayo experimental auto-controlado con 10 voluntarios (16-18 años), futbolistas de ligas menores de un destacado club local. Dos pruebas en cicloergómetro de esfuerzo físico progresivo hasta fatiga, la primera en el Centro de Alto Rendimiento (CAR) a NM (474 mts) y la segunda en villa El Cóndor (EC; 2220mts), província de Córdoba. Protocolo de ejercicio: calentamiento 2', 30Km/hora con 50W; 3 escalones sucesivos de 3'+50W cada uno; fase final 30Km/hora de 200W hasta fatiga y/o síntomas o tiempo máximo de 15'. Mediciones LS y FC: basal, 30'' finales de cada escalón y a fatiga. Determinación LS con ACCusport®. Test de Student para datos apareados a dos colas. Resultados: 1 voluntario no cumplimentó la prueba EC(n=9). Promedio LS basal 2,1 mmol/L en NM y EC(p=0,897), diferencia media EC vs. NM más o menos error estándar de 0,5 más o menos (p=0,033), 0,9 más o menos 0,3(p=0,008) y 0,6 más o menos 0,3mmol/L(p=0,103) en escalón 1, 2 y 3 respectivamente de esfuerzo sub-máximo. En fatiga (pico), LS medio e IC95% de 7,6 (6,5-8,8) y 9,5 (7,8-11,2) mmol/L en NM y EC respectivamente (p=0.030). FC sin cambios en EC respecto a NM. 66% con mayor escala de Borg y 33% de mareos en EC. Conclusión: A una latitud efectiva de 1700mts, sin aclimatación, se verificó un menor desempeño aeróbico junto a la percepción subjetiva de mayor intensidad del esfuerzo, pudiendo...

With the same intensity of sub-maximum effort, the concentration of serum (LS) or muscular lactate is higher in Hypoxia conditions, or exercise at an altitude without acclimation, in relation with normoxia or at sea level (MSL). The highest level of lactate after fatigue or in a test of strict anaerobic condition, would not be modified when altitude changes without previous acclimation. OBJECTIVE: To abtain local data about the magnitude of the affect in SL of a effective altitude at 1,700 meters without acclimation, as a parameter of aerobic performance of young soccer players of our environment who live and train at sea level. VOLUNTEERS AND METHODS: Self-controlled experimental test with a number of 10 volunteers (16 - 18 years-old), soccer players of lower leagues from an important local sport club. Two tests in a cycle ergometer of a graded physical effort until fatigue, the first one in the Center of High Performance at MSL (474 meters) and the second one in the town El Condor (EC; 2.220 meters), province of Cordoba. Exercise Protocol: warm-up 2', 30 Km/h with 50W; 3consecutive steps of 3' + 50W each one; final phase 30 Km/h of 200W until fatigue and/or symptoms or maximum time of 15'. SL and HR measurement: basal; the last 30" of every step and in fatigue. SL determination with Accusport. Two-tailed paired test. RESULTS: 1 volunteer dropped out befote completion in EC (n=9). Mean basal SL 2.1 mmol/L at MSL and EC (p=0.897). Mean difference (MD) EC vs. MSL +/- Standard error of 0.5 +/- 0.2 (p=0.033), 0.9 +/- 0.3 (p=0.008) and 0.6 +/- 0.3 mmol/L (p=0.103) in steps 1, 2, 3 respectively of sub-maximum effort. In fatigue (the highest level), Mean SL and Confidence Interval (CI) 95% of 7.6 (6.5-8.8) and 9.5 (7.8-11.2) mmol/L at MSL and EC respectively (p=0.030). Heart Rhythm (HR) without changes in EC in relation to MSL. 66% with a greater Borg scale and 33% of dizziness at EC. CONCLUSION: At an effective altitude at 1,700 meters without...

Effect of simulated ascent to 3500 meter on neuro-endocrine functions.

Ascent to extreme High Altitude (HA) is in steps and it entails acclimatization at moderately HA locations. In terms of acclimatization, it is pertinent to understand the physiological changes, which occur on immediate ascent to moderate HA. The study aimed to evaluate the effect of ascent to 3500 m on neuro-endocrine responses in the first hour of induction. The plasma levels of catecholamines and cortisol were measured before and after one hour of ascent to high altitude. The peripheral oxygen saturation (SpO2), Galvanic Skin Resistance (GSR), Heart Rate (HR) and Blood Pressure (BP) were simultaneously monitored. The plasma epinephrine, norepinephrine, dopamine and cortisol were increased after one-hour exposure to 3500 m altitude as compared to before exposure. The SpO2 showed a significant decrease during and after high altitude induction. The heart rate and diastolic BP increased at 3500 m whereas the GSR did not show significant changes. There are changes in neuroendocrine responses, which reflect a sympathetic over activity in the first hour of exposure to 3500 m.

Precisión y exactitud de un oxímetro de pulso "de bolsillo" en la ciudad de México / Precision and accuracy of "a pocket"pulse oximeter in Mexico City

Background. Pulse oximeters are frequently used in the clinical practice and we must known their precision and accuracy. The objective was to evaluate the precision and accuracy of a "pocket" pulse oximeter at an altitude of 2,240 m above sea level. Methods. We tested miniature pulse oximeters (Onyx 9,500, Nonin Finger Pulse Oximeter) in 96 patients sent to the pulmonary laboratory for an arterial blood sample. Patients were tested with 5 pulse oximeters placed in each of the fingers of the hand oposite to that used for the arterial puncture. The gold standard was the oxygen saturation of the arterial blood sample. Results. Blood samples had SaO2 of 87.2 ± 11.0 (between 42.2 and 97.9%). Pulse oximeters had a mean error of 0.28 ± 3.1%. SaO2 - (1.204 x SpO2) - 17.45966 (r = 0.92, p < 0.0001). Intraclass correlation coefficient between each of five pulse oximeters against the arterial blood standard ranged between 0.87 and 0.99. HbCO (2.4 ± 0.6) did not affect the accuracy. Conclusions. The miniature oximeter Nonin is precise and accurate at 2,240 m of altitude. The observed levels of HbCO did not affect the performance of the equipment. The oximeter good performance, small size and low cost enhances its clinical usefulness.

Introducción. Los oxímetros de pulso son ampliamente utilizados en la práctica clínica y su precisión y exactitud deben conocerse especialmente en altitudes moderadas como en la ciudad de México. El objetivo principal fue evaluar la precisión y exactitud de un oxímetro de pulso "de bolsillo" (Onyx 9500 de Nonin®) en la ciudad de México. Métodos. Se realizaron mediciones de la saturación de oxígeno estimada por el oxímetro de pulso (SpO2) y se compararon contra la medida espectrofotométricamente en sangre arterial (SaO2) en 96 pacientes que acudieron al laboratorio de fisiología pulmonar del Instituto Nacional de Enfermedades Respiratorias. A cada paciente se le colocaron cinco oxímetros de pulso en los dedos de una mano obteniéndose un promedio de SpO2 para cada uno de los oxímetros y para los cinco oxímetros a la vez, mediciones que se compararon de manera simultánea contra el estándar. Resultados. Las muestras sanguíneas de los 96 pacientes que participaron tuvieron una SaO2 de 87.2 ± 11.0 (entre 42.2-97.9%). Los oxímetros (promedio de los cinco) tuvieron un error de medición promedio de 0.28 ± 3.1%. SaO2 = (1.204 x SpO2) - 17.45966 (r = 0.92, p < 0.0001). Los coeficientes de correlación intraclase que se obtuvieron al comparar los oxímetros entre sí y contra el estándar (SaO2) estuvieron entre 0.87 y 0.99. El nivel de carboxihemoglobina (HbCO) fue de 2.4 ± 0.6% y no afectó significativamente la exactitud del oxímetro. Conclusiones. El oxímetro digital de pulso "de bolsillo" es preciso y exacto en la estimación de la SaO2 a 2,240 metros de altitud. Los niveles observados de HbCO (2.4%) no afectaron su exactitud. Se observó un adecuado desempeño del oxímetro digital de pulso en la ciudad de México.

Lactato sérico como marcador prognóstico em criancas gravemente doentes / Blood lactate concentration as prognostic marker in critically ill children

OBJETIVO: Verificar a utilidade do lactato como marcador de hipoperfusão tecidual e como índice prognóstico em criancas criticamente doentes. MÉTODOS: Estudo prospectivo, longitudinal, tipo observacional de 75 pacientes admitidos na UTI pediátrica do Hospital de Clínicas (UFPR) entre novembro de 1998 e maio de 1999. De acordo com o nível de lactato na admissão, os pacientes foram divididos em grupo A (lactato > 18 mg/dl) e grupo B (lactato < 18 mg/dl). Com relacão à evolucão, em sobrevivente e óbito. No grupo A, a avaliacão clínica e a coleta de amostras de sangue arterial foram realizadas na admissão, 6, 12, 24, 48 horas e, posteriormente, a cada 24 horas. No grupo B, foram realizadas nos mesmos horários e interrompidas com 48 horas após admissão. RESULTADOS: No grupo A, foram incluídos 50 pacientes, e no Grupo B, 25. O grupo A apresentou maior freqüência de sinais clínicos de hipoperfusão (24/50). Houve diferenca estatisticamente significativa da média de lactato na admissão entre os pacientes que foram a óbito nas primeiras 24 horas de internacão (95 mg/dl) quando comparados àqueles que evoluíram a óbito após 24 horas de admissão (28 mg/dl). O nível de lactato na avaliacão de 24 horas de UTI foi o que apresentou melhor sensibilidade (55,6 por cento) e especificidade (97,2 por cento) como parâmetro preditor de óbito. CONCLUSÕES: A maioria dos pacientes com lactato > 18 mg/dl evidenciou sinais clínicos de hipoperfusão na admissão. A normalizacão ou diminuicão dos níveis de lactato a partir de 24 horas de internacão esteve significativamente relacionada com a maior probabilidade de sobrevida.

Comparison of blood gas values in arterial and venous blood.

OBJECTIVE: To compare pH and PCO2 values of simultaneously obtained arterial, arterialized capillary, and venous blood samples and also to compare oxygen saturation (ASaO2) measured in arterial blood and oxygen saturation by pulse oximetry (PSaO2). METHODS: Prospective study was done in the children admitted in the Pediatric Intensive Care Unit of Christian Medical College Hospital Vellore, requiring critical care. All the three blood gas samples (arterial, capillary and venous) were taken simultaneously and analyzed. Oxygen saturation by pulse oximetry was also recorded. RESULTS: 50 children aged 14 days to 12 years were included in the study. Arterial and capillary pH values were highly correlated (r2=0.9024, p<0.0001). Out of 16 children with arterial acidosis 9(56%) were identified by capillary blood gas. Arterial and venous pH values also showed good correlation (r2=0.8449, p<0.0001). The PCO2 values of arterial and capillary blood gases were found to be highly correlated (r2=0.9534, p<0.0001). The capillary blood gas accurately reflected the arterial PCO2 in 41 (82%) patients. Arterial and venous blood gas PCO2 values had less correlation (r2=0.5917, p=0.011). The arterial oxygen saturation (ASaO2) and oxygen saturation by pulse oximetry (PSaO2) were correlated moderately (r2=0.7241, p<0.0001). CONCLUSION: Even though arterial blood gas analysis is the gold standard, and when an arterial blood gas sample cannot be obtained, a combination of arterialized capillary blood gas and pulse oximetry can be effectively used in acutely ill children of all ages. Venous samples have a good correlation with arterial samples for pH but are not useful for monitoring blood gas status in acutely ill children.

Risk factors for hypoxemia and respiratory failure in respiratory syncytial virus bronchiolitis.

Respiratory syncytial virus (RSV) bronchiolitis is a common infection in young children and may result in hospitalization. We examined the incidence of, and risk factors associated with, hypoxemia and respiratory failure in 216 children aged < 24 months admitted consecutively for proven RSV bronchiolitis. Hypoxemia was defined as SpO2 < 90% in room air and severe RSV bronchiolitis requiring intubation and ventilation was categorized as respiratory failure. Corrected age at admission was used for premature children (gestation < 37 weeks). Hypoxemia was suffered by 31 (14.3%) children. It was more likely to occur in children who were Malay (OR 2.56, 95%CI 1.05-6.23, p=0.03) or premature (OR 6.72, 95%CI 2.69-16.78, p<0.01). Hypoxemia was also more likely to develop in children with failure to thrive (OR 2.96, 95%CI 1.28-6.82, p<0.01). The seven (3.2%) children who were both premature (OR 11.94, 95%CI 2.50-56.99, p<0.01) and failure to thrive (OR 6.41, 95%CI 1.37-29.87, p=0.02) were more likely to develop respiratory failure. Prematurity was the only significant risk factor for hypoxemia and respiratory failure by logistic regression analysis (OR 1.17, 95%CI 1.06-1.55, p<0.01 and OR 1.14 95%CI 1.02-2.07, p=0.02 respectively). Prematurity was the single most important risk factor for both hypoxemia and respiratory failure in RSV bronchiolitis.

Comparison between two different modes of oxygen therapy during immediate postoperative period following mitral commisurotomy.

Hypoxaemia is a common postoperative problem after thoracotomy. Oxygen therapy with continuous monitoring by pulse oximetry should be a routine practice. This study was conducted to compare the efficacy between nasal cannula and ventimask for post-thoracotomy oxygen supplementation on 20 patients divided into 2 groups of 10 each undergoing closed mitral commisurotomy. The study period was of 5 months duration from March to July, 1996. The mean oxygen saturation remained above 98% in both the groups receiving oxygen either by nasal cannula or ventimask. As there was adequate oxygenation, the cost benefit ratio favours the use of nasal cannula for routine postoperative oxygen supplementation in the closed mitral commisurotomy patients.