Arterial Blood Gases in Normal Subjects at 2240 Meters Above Sea Level: Impact of Age, Gender, and Body Mass Index

ABSTRACT Background The values of arterial blood gases (ABG) change with altitude above sea level; empirical verification is essential because ventilatory acclimatization varies with ethnicity and a population's adaptation. Objective The aim of the study was to describe ABG in a healthy population residing at 2,240 meters above sea level, to identify the mean level of alveolar ventilation (PaCO2), and to know whether a progressive increase in PaCO2 occurs with age and the impact of increasing body mass index (BMI). Methods We conducted a cross-sectional study in a referral center for respiratory diseases in Mexico City. Associations among variables with correlation coefficient and regression models of PaO2, SaO2, and P(A-a)O2 as dependent variables as a function of age, BMI, minute ventilation, or breathing frequency were explored. Results Two hundred and seventeen healthy subjects were evaluated with a mean age of 40 ± 15 years, mean of the PaO2 was 71 ± 6 mmHg, SaO2 94% ± 1.6%, PaCO2 30.2 ± 3.4 mmHg, HCO3 20 ± 2 mmol/L, BE-2.9 ± 1.9 mmol/L, and the value of pH was 7.43 ± 0.02. In a linear regression, the main results were PaO2 = 77.5-0.16*age (p < 0.0001) and with aging P(A-a)O2 tended to increase 0.12 mmHg/year. PaCO2 in women increased with age by 0.075 mmHg/year (p = 0.0012, PaCO2 =26.3 + 0.075*age). SaO2 and PaO2 decreased significantly in women with higher BMI 0.14% and 0.52 mmHg per kg/m2, (p = 0.004 and 0.002 respectively). Conclusion Mean PaCO2 was 30.7 mmHg, implying a mean alveolar ventilation of around 30% above that at sea level.

Delta de CO2 como estrategia del manejo integral del paciente con choque séptico en la UCI / CO2 delta as a strategy for the comprehensive management of patients with septic shock in the ICU / Delta CO2 como estratégia para o tratamento integral do paciente com choque séptico na UTI

Resumen: Introducción: el choque séptico es un subconjunto de sepsis en el que las anomalías circulatorias, celulares y metabólicas subyacentes son lo suficientemente profundas para aumentar de manera sustancial la mortalidad. Estos pacientes pueden ser identificados en un contexto clínico de choque séptico con hipotensión persistente. La importancia de vigilar valores de delta de pCO2 (presión parcial de dióxido de carbono) de 6 mmHg sirve como herramienta complementaria para evaluar el flujo sanguíneo adecuado hacia la demanda metabólica global. Objetivo: demostrar que el delta de pCO2 es útil en el manejo integral del paciente con choque séptico en la unidad de cuidados intensivos para dirigir el tratamiento de acuerdo con este biomarcador, que se registró al ingreso y a las 24 horas, se relacionaron al pronóstico y a la mortalidad en choque séptico. Material y métodos: estudio descriptivo, ambispectivo, longitudinal y analítico. El universo se compuso de los pacientes que ingresaron a la Unidad de Cuidados Intensivos del Hospital General «La Villa¼ y del Hospital General «Dr. Rubén Leñero¼. Diseño de la maniobra: se tomaron gasometrías arterial y venosa de los pacientes que ingresaron a la UCI, se calculó el delta de pCO2 para ver si los valores de este biomarcador estaban por arriba o debajo de 6 mmHg, ya que un delta de pCO2 se relaciona con mortalidad; sin embargo, el delta de pCO2 se comparó contra el lactato para correlacionar niveles mayores de lactato de 2 mmol/L con la mortalidad. y finalmente observar cuál de los dos biomarcadores es más útil. Se utilizó estadística descriptica para los resultados. Conclusión: de acuerdo a los resultados encontrados en este estudio, se puede decir que el delta de pCO2 y el lactato predijeron el fallecimiento de 15%, lo cual tiene una significancia positiva débil (p = 0.245).

Abstract: Introduction: septic shock is a subset of sepsis in which underlying circulatory, cellular, and metabolic abnormalities are profound enough to substantially increase mortality. These patients can be identified in a clinical setting of septic shock with persistent hypotension. The importance of monitoring delta pCO2 values of 6 mmHg serves as a complementary tool to assess adequate blood flow towards global metabolic demand. Objective: to demonstrate that the pCO2 delta is useful in the comprehensive management of patients with septic shock in the Intensive Care Unit to direct the treatment according to this biomarker (pCO2 delta) that was recorded at admission and at 24 hours, were related to prognosis and mortality in septic shock. Material and methods: descriptive, ambispective, longitudinal and analytical study. The universe was made up of patients admitted to the ICU of the La Villa and Rubén Leñero General Hospitals. Maneuver design: arterial and venous blood gases were taken from the patients admitted to the ICU, the pCO2 delta was calculated to see if the values of this biomarker were above or below 6 mmHg, since a pCO2 delta is related to with mortality; however, delta pCO2 was compared against Lactate to correlate lactate levels greater than two with mortality and finally see which of the two biomarkers is more useful. Descriptive statistics were used for the results. Conclusion: according to the results found in this study, it can be said that delta pCO2 and lactate predicted the death of 15%, which has a weak positive significance (p = 0.245).

Resumo: Introdução: choque séptico é um subconjunto de sepse em que anormalidades circulatórias, celulares e metabólicas subjacentes são profundas o suficiente para aumentar substancialmente a mortalidade, esses pacientes podem ser identificados em um cenário clínico de choque séptico com hipotensão persistente. A importância do monitoramento de valores Delta de pCO2 de 6 mmHg serve como ferramenta complementar para avaliar o fluxo sanguíneo adequado à demanda metabólica global. Objetivo: demonstrar que o Delta pCO2 é útil no manejo integral de pacientes com choque séptico na Unidade de Terapia Intensiva para direcionar o tratamento de acordo com este biomarcador (Delta pCO2) que foi registrado na admissão e em 24 horas, relacionado ao prognóstico e mortalidade no choque séptico. Material e métodos: estudo descritivo, ambispectivo, longitudinal e analítico. O universo foi constituído pelos pacientes internados na UTI dos Hospitais Gerais La Villa e Rubén Leñero. Desenho da estratégia: foram coletadas gasometrias arteriais e venosas dos pacientes internados na UTI, o Delta pCO2 foi calculado para ver se os valores desse biomarcador estavam acima ou abaixo de 6 mmHg, pois um Delta pCO2 está relacionado com mortalidade; entretanto, Delta pCO2 foi comparado com Lactato para correlacionar níveis de lactato maiores que 2 com mortalidade e finalmente observar qual dos dois biomarcadores é mais útil. Foram usadas estatísticas descritivas para os resultados. Conclusão: de acordo com os resultados encontrados neste estudo, pode-se dizer que Delta pCO2 e Lactato predizem óbito em 15%, o que tem uma fraca significância positiva (p = 0.245).

Alteraciones del estado ácido básico en pacientes adultos con insuficiencia renal crónica / Acid-base status alterations in adult patients with chronic renal failure

RESUMEN Introducción: el portador de insuficiencia renal crónica puede presentar diversas alteraciones del estado ácido básico, siendo la acidosis metabólica la más frecuente. Objetivos: describir las características demográficas y clínicas y las alteraciones del estado ácido básico de pacientes adultos que ingresan con insuficiencia renal crónica en dos centros hospitalarios del Paraguay. Metodología: se aplicó un diseño observacional, descriptivo, transversal. Se incluyó a sujetos adultos de ambos sexos, portadores de insuficiencia renal crónica, que acudieron al Hospital Nacional (Itauguá) y Hospital Militar (Asunción) entre abril y noviembre del 2021. Se midieron variables antropométricas, clínicas y laboratoriales al ingreso. Los datos se sometieron a estadística descriptiva con el programa Epi Info 7™. El estudio contó con la aprobación del Comité de Ética de la Universidad Privada del Este, Paraguay. Resultados: se incluyó a 148 sujetos, siendo 78 (52,7 %) varones con edad media 58 ± 16 años y 70 (47,3 %) mujeres con edad media 54 ± 17 años. Las etiologías más frecuentes de la insuficiencia renal crónica fueron la diabetes mellitus e hipertensión arterial (44,5 %). Se detectó 12 sujetos (8,1 %) con gasometría normal. La alteración del estado ácido básico más frecuente fue la acidosis metabólica (87,2 %), predominando en este grupo los casos con brecha aniónica normal. Conclusiones: las alteraciones del estado ácido básico predominantes en pacientes con insuficiencia renal crónica fue la acidosis metabólica con brecha aniónica normal. Se sugiere aplicar los cálculos de los mecanismos compensadores para llegar al diagnóstico certero de estas alteraciones metabólicas.

ABSTRACT Introduction: the carrier of chronic renal failure can present various alterations of the basic acid state, being the metabolic acidosis the most frequent. Objectives: to describe the demographic and clinical characteristics and alterations in the acid-base status of adult patients admitted with chronic renal failure in two hospitals in Paraguay. Methodology: an observational, descriptive, cross-sectional design was applied. Adult subjects of both sexes, carriers of chronic renal failure, who attended the National Hospital (Itauguá) and the Military Hospital (Asunción) between April and November 2021 were included. Anthropometric, clinical and laboratory variables were measured at admission. The data was submitted to descriptive statistics with the Epi Info 7™ program. The study was approved by the Ethics Committee of the Universidad Privada del Este, Paraguay. Results: 148 subjects were included, being 78 (52.7 %) men with a mean age of 58 ± 16 years and 70 (47.3 %) women with a mean age of 54 ± 17 years. The most frequent etiologies of chronic renal failure were diabetes mellitus and arterial hypertension (44.5 %). 12 subjects (8.1 %) with normal blood gases were detected. The most frequent alteration of the acid-base status was metabolic acidosis (87.2 %), with cases with normal anion gap predominating in this group. Conclusions: the predominant acid-base status alterations in patients with chronic renal failure was metabolic acidosis with normal anion gap. It is suggested to apply the calculations of the compensatory mechanisms to arrive at the accurate diagnosis of these metabolic alterations.

Valores de la gasometría arterial en pacientes embarazadas con preeclampsia severa / Arterial blood gas parameters in pregnant patients with severe preeclampsia

Resumen OBJETIVO: Determinar e interpretar los valores de la gasometría arterial en pacientes embarazadas con preeclampsia severa. MATERIALES Y MÉTODOS: Estudio observacional, transversal, retrospectivo y descriptivo llevado a cabo en pacientes con más o menos 20 semanas de embarazo y diagnóstico establecido de preeclampsia severa atendidas en la unidad de cuidados intensivos entre el 1 de julio y el 31 de diciembre del 2019. Los datos generales, la condición obstétrica, los estudios de laboratorio clínico y los valores de la gasometría arterial se documentaron conforme a lo registrado en los expedientes clínicos. Se utilizó estadística descriptiva y los datos se procesaron en el programa SPSS versión 20. RESULTADOS: Se estudiaron 30 pacientes con media de edad de 31.6 ± 6.85 años, mediana de paridad 1, todas con feto único de 33.89 ± 3.43 semanas y residencia en la Ciudad de México. Los valores de la gasometría arterial fueron: pH 7.41 ± 0.08, presión parcial de dióxido de carbono 25.51 ± 6.12 mmHg, presión parcial de oxígeno 85.24 ± 41.81 mmHg, hematocrito 33.86 ± 7.51%, ión carbonato 16.95 ± 5.13 mmol/L, patrón de bicarbonato estandarizado 19.04 ± 2.50 mmol/L, gases de efecto invernadero 16.94 ± 2.51 mmHg, exceso de base del fluido extracelular -7.72 ± 5.60 mmol/L, BE (B) -7.36 ± 3.07 mmol/L, porcentaje de saturación de oxígeno 93 ± 8.29, hemoglobina total en la gasometría arterial 10.64 ± 2.36 g/dL, gradiente alvéolo-arterial de oxígeno 49.43 ± 10.98 mmHg, presión parcial de oxígeno 140.43 ± 106.93 mmHg, concentraciones de dióxido de carbono 0.79 ± 0.28 mmHg e Índice respiratorio 0.95 ± 2.57. CONCLUSIONES: Los resultados corresponden a un patrón gasométrico de acidosis metabólica compensada.

Abstract OBJECTIVE: To determine and interpret arterial blood gas values in pregnant patients with severe preeclampsia. MATERIALS AND METHODS: study carry out in a series of 30 patients with a pregnancy ≥ 20 weeks and an established diagnosis of SP admitted to the Intensive Care Unit from July 1 to December 31, 2019, in whom arterial blood gases are part of the routine studies upon admission to the ICU. Patients with recurrence of preeclampsia, eclampsia and HELLP syndrome or with metabolic, respiratory, cardiological and renal morbidities affecting arterial blood gas values were excluded. The general data, obstetric condition, clinical laboratory and arterial blood gas values were documented from the clinical records. Statistical analysis: descriptive statistics were used with the statistical package SPSS version 20. RESULTS: Thirty patients were studied, with a mean age of mean age 31.6 ± 6.85 years, median parity 1, all with a single product of 33.89±3.43 weeks and residence in Mexico City 31.37 ± 7 years. Arterial blood gas values were: pH 7.41 ± 0.08, PCO2 25.51 ± 6.12 mmHg, PO2 85.24 ± 41.81 mmHg, Hct 33.86 ± 7.51%, HCO3- 16.95 ± 5.13 mmol/L, HCO3- std 19.04 ± 2.50 mmol/L, TCO2 16.94 ± 2.51 mmHg, BE ecf -7.72 ± 5.60 mmol/L, BE (B) -7.36 ± 3.07 mmol/L, SO2c% 93 ± 8.29%, THbc 10.64 ± 2.36 g/dL, Aa DO2 49.43 ± 10.98 mmHg, pAO2 140.43 ± 106.93 mmHg, PaO2/PAO2 0.79 ± 0.28 mmHg and Respiratory Index 0.95 ± 2.57. CONCLUSIONS: The results correspond to a gasometric pattern of compensated metabolic acidosis.

Aclaramiento de lactato y déficit de base estándar como pronóstico de mortalidad en choque séptico / Lactate clearance and standard base deficit as a prognosis of mortality in septic shock / Depuração de lactato e deficiência de base padrão como prognóstico de mortalidade no choque séptico

Resumen: Introducción: la asociación del nivel de lactato con la mortalidad en pacientes con sospecha de infección y sepsis está bien establecida. La sensibilidad es entre 66 y 83%, con especificidad de 80 y 85%. Sin embargo, el lactato no es sensible ni lo suficientemente específico para detectar o descartar el diagnóstico por sí solo, ya que el lactato sérico es un biomarcador importante de la hipoxia y disfunción tisular, pero no es una medida directa de la perfusión tisular. El lactato y la base estándar medidos al ingreso a la Unidad de Cuidados Intensivos (UCI) son de utilidad pronóstica en los pacientes críticamente enfermos, pues sus niveles séricos predicen mortalidad a través de la puntuación en sí misma. Pero la importancia real va más allá de un valor absoluto, pues es mejor medir su aclaramiento a través de un tiempo determinado. Objetivo: demostrar que el aclaramiento de lactato y déficit de base estándar registrados al ingreso y a las 24 h se relacionan con mejor pronóstico y disminución de mortalidad en choque séptico. Material y métodos: se utilizó estadística descriptiva (medidas de tendencia central y dispersión; así como frecuencias y porcentajes). Asimismo, se ocupó estadística inferencial con la prueba t de Student, χ2, curva ROC, área bajo la curva e índice de Youden, con un intervalo de confianza de 95%. Resultados: la asociación estadística con la mortalidad se presentó en el aclaramiento de déficit de base estándar y en aclaramiento de lactato. Conclusión: se demostró que el aclaramiento de lactato y déficit de base estándar registrados al ingreso y a las 24 h se relacionaron con mejor pronóstico y disminución de mortalidad en pacientes con choque séptico.

Abstract: Introduction: the association of lactate level with mortality in patients with suspected infection and sepsis is well established. Sensitivity is between 66 and 83%, with specificity between 80 and 85%. However, lactate is neither sensitive nor specific enough to detect or rule out the diagnosis on its own as serum lactate is an important biomarker of tissue hypoxia and dysfunction but is not a direct measure of tissue perfusion. Lactate and standard base measured on admission to the Intensive Care Unit (ICU) are useful for prognosis in critically ill patients since their serum levels predict mortality through the score itself. But the real importance goes beyond an absolute value, since it is better to measure its clearance over a given time. Objective: to demonstrate that lactate clearance and standard base deficit recorded at admission and at 24 hours are related to a better prognosis and decreased mortality in septic shock. Material and methods: descriptive statistics were used (measures of central tendency and dispersion, as well as frequencies and percentages). Likewise, inferential statistics were used with the Student's t test, χ2, ROC curve, area under the curve and Youden index, with a confidence interval of 95%. Results: the statistical association with mortality was presented in the clearance of standard base deficit and in lactate clearance. Conclusion: it was shown that lactate clearance and standard base deficit recorded at admission and at 24 hours were related to a better prognosis and decreased mortality in patients with septic shock.

Resumo: Introdução: a associação do nível de lactato com mortalidade em pacientes com suspeita de infecção e sepse está bem estabelecida. A sensibilidade está entre 66 e 83%, com especificidade de 80 e 85%. No entanto, o lactato não é sensível nem específico o suficiente para detectar ou descartar o diagnóstico por si só, uma vez que o lactato sérico é um importante biomarcador de hipóxia e disfunção tecidual, mas não é uma medida direta da perfusão tecidual. O lactato e a base padrão medidos na admissão na UTI são de utilidade prognóstica em pacientes críticos, uma vez que seus níveis séricos predizem a mortalidade pelo próprio escore. Mas a real importância vai além de um valor absoluto, pois é melhor medir sua depuração em um determinado tempo. Objetivo: demonstrar que a depuração de lactato e o déficit de base padrão registrados na admissão e em 24 horas estão relacionados a um melhor prognóstico e diminuição da mortalidade no choque séptico. Material e métodos: foi utilizada estatística descritiva (medidas de tendência central e dispersão, bem como frequências e percentagens). Da mesma forma, foi utilizada estatística inferencial com teste t de Student, χ2, curva ROC, área sob a curva e índice de Youden, com intervalo de confiança de 95%. Resultados: a associação estatística com a mortalidade foi apresentada na depuração do déficit de base padrão e na eliminação do lactato. Conclusão: foi demonstrado que a depuração de lactato e o déficit de base padrão registrados na admissão e em 24 horas foram relacionados a um melhor prognóstico e diminuição da mortalidade em pacientes com choque séptico.

Adding autogenic drainage to chest physiotherapy after upper abdominal surgery: effect on blood gases and pulmonary complications prevention. Randomized controlled trial

ABSTRACT BACKGROUND: Hypoxemia and pulmonary complications are common after upper abdominal surgery (UAS). OBJECTIVE: To examine whether inclusion of autogenic drainage (AD) in chest physiotherapy after UAS confers additional benefits in improving blood gases and reducing postoperative pulmonary complications (PPCs). DESIGN AND SETTING: Randomized controlled study conducted at Kasr Al-Ainy teaching hospital, Egypt. METHODS: A randomized controlled trial was conducted on 48 subjects undergoing elective UAS with high risk of developing PPCs. The study group received AD plus routine chest physiotherapy (deep diaphragmatic breathing, localized breathing and splinted coughing) and the control group received routine chest physiotherapy only. The outcomes included arterial blood gases measured at the first and seventh postoperative days, incidence of PPCs within the first seven days and length of hospital stay. RESULTS: Baseline characteristics were similar between groups. In the AD group, SaO2, PaO2, PaCO2 and HCO3 significantly improved (P < 0.05) while in the physiotherapy group, only SaO2 and PaO2 significantly improved (P < 0.05). Nonetheless, significant differences in post-treatment SaO2 and PaO2 between the groups were observed. The overall incidence of PPCs was 16.66% (12.5% in the AD group and 20.8% in the physiotherapy group) (absolute risk reduction -8.3%; 95% confidence interval, CI, -13.5 to 29.6%), with no significant difference between the groups. The AD group had a significantly shorter hospital stay (P = 0.0001). CONCLUSION: Adding AD to routine chest physiotherapy after UAS provided a favorable blood gas outcome and reduced the length of hospital stay. It tended to reduce the incidence of PPCs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04446520.

Gasometría arterial en embarazo a muy alta altitud / Arterial blood gas analysis during pregnancy at a very high altitude

La gasometría arterial es fundamental en el diagnóstico y manejo del medio interno. El objetivo es caracterizar los valores de gasometría arterial en gestantes sanas con embarazo normoevolutivo residentes a 4 150 metros sobre el nivel del mar. Serie de casos llevada a cabo durante la gestión 2019, la cual incluye pacientes sin clínica ni antecedentes de enfermedades cardiopulmonares o hematológicas, así como ausencia de tabaquismo y residencia de al menos los últimos 6 meses. Se incluye 30 pacientes, media de edad 25.23 años (desvío estándar 3.69), con edad gestacional media de 26 semanas (desvío estándar 5.5). El valor de pH tiende a ser más alto, así como los valores de PaO2, PaCO2, HCO3 y SatpO2% son más bajos, incluso en comparación con adultos sanos residentes de la misma altitud. Existe cierta tendencia positiva hacia el incremento progresivo del pH mientras la edad gestacional avanza. La gasometría arterial en la altura, debe ser interpretada con suma precaución en relación a las condiciones barométricas, proporcionándose así, valiosa información con aplicación a la obstetricia crítica a muy alta altitud.

Arterial blood gases analysis is essential in the diagnosis and management of pathologies. The objective is to characterize arterial blood gases values in healthy pregnant residents at 4150 meters above sea level. Series case performed during 2019, including patients without a clinical features or antecedents of cardiopulmonary or hematological diseases as well as absence of smoking and residence for at least the last 6 months. Thirty patients are included, mean age 25.23 years (standard deviation 3.69), with average gestational age of 26 weeks (standard deviation 5.5). The pH tends to be higher, as well as the values of PaO2, PaCO2, HCO3 and SatpO2% are lower, even compared to healthy adults living at the same altitude. There is some positive trend towards progressive pH is higher such as gestational age progresses. Arterial gas blood analysis at altitude, should be interpreted with extreme caution in relation to barometric conditions, thus providing, valuable information to critical care obstetrics at very high altitude

Efectos cardiopulmonares y ácido-base de la infusión continua de fentanilo, ketamina y lidocaína en pacientes caninos ASA I / Cardiopulmonary and acid-base effects of continuous infusion of fentanyl, ketamine and lidocaine in canines ASA I / Efeitos cardio-pulmonares e ácido-base da infusão contínua de fentanil, cetamina e lidocaína em pacientes caninos ASA I

Resumen La combinación de fentanilo, lidocaína y ketamina (FLK) se ha utilizado am- pliamente en la cirugía canina como parte del protocolo analgésico. Algunos efectos asociados con su aplicación han sido descritos por la literatura. El objetivo del presente trabajo fue evaluar los efectos cardiopulmonares pro- ducidos por la infusión de FLK y el uso de isoflurano durante la cirugía en pacientes caninos ASA I. Las muestras fueron tomadas de nueve hembras caninas de diferentes razas, edades y tamaños que se presentaron para la ovariohisterectomía y recibieron una infusión continua de FLK (0,08, 30 y 15 µg/kg/min, respectivamente) como parte del protocolo analgésico. Antes (tiempo 1; T1) y durante (tiempo 2; T2) la cirugía se tomaron medidas de fre- cuencias cardíaca y respiratoria, presión arterial no invasiva, índice y gasto cardíaco, saturación arterial de oxígeno, dióxido de carbono espirado, tempe- ratura, presión parcial arterial de dióxido de carbono y oxígeno, bicarbonato, pH sanguíneo, dióxido de carbono total y lactato sanguíneo. Los resultados de la temperatura corporal y el pH en T1 y T2 fueron estadísticamente dife- rentes (p<0,05). Se concluye que no hubo diferencia entre los efectos de las variables cardiorrespiratorias y hemodinámicas en T1 y T2. Los resultados encontrados indican que los cambios en el pH y la temperatura se dieron por factores adicionales a la infusión FLK. Aunque las variables cardiovasculares y hemodinámicas no se encontraron como significativas, fue posible observar una mejora en la perfusión tisular y la estabilidad hemodinámica.

Abstract The combination of fentanyl, lidocaine, and ketamine (FLK) has been widely used in canine surgery as part of the analgesic protocol. Some effects associated with its application have been described by the literature. The objective was to evaluate the cardiopulmonary effects produced by the infusion of FLK and the use of isoflurane during surgery in canine ASA I patients. Samples was taken of nine healthy female dogs of different breeds, ages, and sizes undergoing ovariohysterectomy that received a continuous infusion of FLK (0,08, 30, and 15 µg/kg/min, respectively) as part of the analgesic protocol. The results of cardiac and respiratory rates, non-invasive blood pressure monitoring, cardiac output and index, arterial oxygen sa- turation, end-tidal carbon dioxide, body temperature, arterial partial pressure of carbon dioxide and oxygen, bicarbonate, blood pH, total carbon dioxide, and blood lactate were measured before (time 1; T1) and during (time 2; T2) the surgery. Body temperature and acid base status at T1 and T2 were statistically different (p<0,05). In contrast, there was no difference between the effects of the analgesic protocol on cardiorespiratory and hemodynamic variables at T1 and T2. The results found indicate that changes in pH and temperature were due to additional factors different conditions outside the FLK infusion. Al- though cardiovascular and hemodynamic variables were not found as significant, it was possible to observe an improving on tissue per- fusion and hemodynamic stability.

Resumo A combinação de fentanil, lidocaína e cetamina (FLK) tem sido amplamente utilizada em cirurgia canina como parte do protocolo analgésico. Alguns efeitos associados à sua aplicação foram descritos na literatura. O objetivo do presente trabalho foi avaliar os efeitos cardiopulmonares produzidos pela infusão de FLK e o uso de iso- flurano durante a cirurgia em pacientes caninos ASA I. As amostras foram coletadas de nove fêmeas caninas de diferentes raças, idades e tamanhos apresentados para ovario-histerectomia e recebeu infusão contínua de FLK (0,08, 30 e 15 µg/kg/min, respectivamente) como parte do protocolo analgésico. Antes (tempo 1; T1) e duran- te (tempo 2; T2) a cirurgia fazia medições das frequências cardíaca e respiratória, pressão arterial não invasiva, índice e débito cardíaco, saturação arterial de oxigênio, dióxido de carbono expirado, temperatura, pressão parcial de dióxido de carbono e oxigênio, bicarbonato, pH no sangue, dióxido de carbono total e lactato no sangue. Os resultados de temperatura corporal e pH em T1 e T2 foram estatisticamente diferentes (p <0,05). Conclui-se que não houve diferença entre os efeitos das variá- veis cardiorrespiratórias e hemodinâmicas em T1 e T2. Os resultados encontrados indicam que alterações no pH e temperatura foram devidas a fatores adicionais à infusão de FLK. Embora as variáveis cardiovasculares e hemodinâmicas não ten- ham sido significativas, foi possível observar uma melhora na perfusão tecidual e na estabilidade hemodinâmica.

Can Venous blood gas be a reliable substitute for Arterial blood gas in modern clinical practice?

Background: It is clearly mentioned in the medicine books that blood gas analysis from arterial puncture is the gold standard. But in the past few years it is commonly seen that clinicians have started trusting on venous blood gas analysis as well as started advising VBG (Venous blood gas) in the initial diagnosis of critical patients in emergency setting. Keeping this fact in mind, we designed a study to determine whether VBG could be a better replacement of ABG (Arterial blood gas) in the emergency where diverse pathological conditions are encountered.Methods: This prospective cross-sectional study comprised of 50 patients of 20-60 yrs age with a variety of diagnoses admitted in the emergency department. 50 paired samples (ABG+VBG) were obtained from them under strict aseptic precautions after obtaining their verbal consent. With a minimum delay of less than 2 min blood gas analysis was performed on blood gas analyzer. Parameters (pH, PCO2, PO2, HCO3, Base Excess and O2 saturation) from ABG and VBG were recorded and compared using Student’s Unpaired ‘t’ test.Results: pH and HCO3 showed statistical significant (p value <0.05) differences between ABG and VBG, while BE showed statistical non-significant (p value >0.05) difference between them. Contrary to this, PCO2, PO2 and O2 saturation from ABG and VBG showed statistical highly significant (p value <0.0001) differences.Conclusions: VBG should not be interchangeably considered in place of ABG with regard to pH, HCO3, PCO2, PO2 and O2 saturation in conditions where actual oxygenation status of patient is required (e.g.; hypovolemic shock, respiratory disorders, mechanically ventilated patients, etc.)

Application of N-acetylcysteine inhalation in treatment of elderly patients with acute exacerbation of chronic obstructive pulmonary disease / 吉林大学学报(医学版)

Objective: To explore the curative effect of N-acetylcysteine (NAC) inhalation in the treatment of the elderly patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and to clarify the application value of NAC in the regular treatment of the AECOPD patients. Methods: A total of 78 elderly patients with AECOPD were enrolled and randomly divided into control group (n=38) and NAC group (n=40). The patients in two groups all received regular treatment; the patients in NAC group received additional NAC inhalation (0. 3 g, 2 times per day) while the patients in control group received normal saline inhalation. The arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), forced expiratory volume in 1 second (FEV1), forced expiratory volume in FEV1 % predicted (FEVl%pred), the clinical COPD Questionnaire (CCQ) score, as well as the rates of intravenous steroid infusion, the incidence of hospital infection and the duration of hospitalization before and after treatment were recorded. Results: Compared with control group, the difference values of PaO2 of the patients in NAC group was significantly increased (P=0. 033), but there were no significant differences in the difference values of PaO2, FEV1 and FEV1% pred (P>0. 05); the CCQ score of the patients in NAC group was significantly higher than that in control group, and there was significant difference in the difference values (P 0.05). Conclusion: NAC inhalation could apparently improve the PaO2 and the clinical symptoms in the elderly AECOPD patients, but has no significant effects on the pulmonary function, the rate of intravenous steroid infusion, the incidence of hospital infection and the duration of hospitalization.

Gasometría arterial en diferentes niveles de altitud en residentes adultos sanos en el Perú / Arterial blood gas analysis at different levels of altitude in healthy adult residents of Peru

Objetivo: Conocer los valores de la gasometría arterial, SatO2, pO2/fiO2 y lactato en los residentes sanos de la altura a dos diferentes niveles de altitud. Materiales y métodos: Reporte de casos. Muestreo por conveniencia. Se describe los valores de gases arteriales en las ciudades de Huánuco (1818 msnm) y Cerro de Pasco (4380 msnm). Resultados: En Huánuco y Cerro de Pasco se encontró: pH: 7.42 (0.02) y 7.43 (0.01), pO2: 78.19 (4.76) y 54.18 (3.12), pO2/fiO2: 372.32 (22.66) y 258.13 (14.77), saturación de oxígeno: 96.24 (0.87) y 87.02 (2.31), lactato: 1.14 (0.49) y 1.47 (0.56), pCO2: 34.63 (3.62) y 27.69 (1.88), y HCO2: 22.56 (2.19) y 18.37 (1.33), respectivamente. Conclusiones: Los valores del análisis de gasometría arterial en la altura en los residentes adultos sanos son diferentes a los planteados como normales para los residentes del nivel del mar. A mayor altitud de residencia, los cambios son más marcados.

Objective: To know the values of arterial blood gases, SatO2, pO2/fiO2 and lactate in healthy high-altitude residents at two different levels of altitude. Materials and methods: Case report. Convenience sampling. Description of the values of arterial blood gases in the cities of Huánuco (1,818 masl) and Cerro de Pasco (4,380 masl). Results: In Huánuco and Cerro de Pasco we found the following values: pH: 7.42 (0.02) and 7.43 (0.01), pO2: 78.19 (4.76) and 54.18 (3.12), pO2/fiO2: 372.32 (22.66) and 258.13 (4.77), oxygen saturation: 96.24 (0.87) and 87.02 (2.31), lactate: 1.14 (0.49) and 1.47 (0.56), pCO2: 34.63 (3.62) and 27.69 (1.88), and HCO2: 22.56 (2.19) and 18.37 (1.33), respectively. Conclusions: The values of the arterial blood gas analysis in healthy high-altitude adult residents are different from the normal values in sea-level residents. The higher the altitude of residence, the more pronounced the changes.

Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters

ABSTRACT This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 µL L−1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 µL L−1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.

Equilíbrio acidobásico, parâmetros urinários e sanguíneos de gatos induzidos ao estresse e suplementados com composto antioxidante / Acid-base balance, urinary and blood parameters of cats stress-induced cats and supplemented with antioxidant compound

Este estudo teve como objetivo avaliar a suplementação do composto antioxidante comercial EconomasE (Alltech, Brasil ( AOX) sobre o equilíbrio acidobásico, os parâmetros urinários, o hemograma completo e a fragilidade osmótica de eritrócitos (FOE) de gatos estressados. Foram utilizados 24 gatos adultos (3,49±0,87kg), distribuídos em delineamento inteiramente ao acaso, com quatro níveis (0, 250, 500, 750mg de AOX/kg de alimento na matéria seca) e seis repetições, durante o período de 80 dias. Os gatos foram induzidos ao estresse por meio da presença de cães próximo ao recinto experimental (agente estressor; AE), do 61º dia até o final do experimento. A pressão parcial de dióxido de carbono (pCO2) e o bicarbonato (HCO3 -) aumentaram linearmente (P<0,05) conforme o aumento da ingestão de AOX. Os maiores valores de dióxido de carbono total (tCO2) (P<0,05) foram observados nos gatos alimentados com 500 e 750mg de AOX/kg de dieta. As concentrações de hemoglobina foram maiores nos animais alimentados com 250 e 500mg de AOX/kg de dieta. Os parâmetros urinários e da FOE foram semelhantes nos gatos em todas as dietas. Esses dados indicam que a suplementação com AOX apresenta efeitos benéficos no equilíbrio acidobásico e na concentração de hemoglobina de gatos induzidos ao estresse.(AU)

This study aimed to evaluate the supplementation of a commercial antioxidant EconomasE (Alltech, Brazil - AOX) on the acid-base balance, urinary parameters, red blood count (RBC) and erythrocyte osmotic fragility (EOF) of stressed cats. Twenty-four adult cats (3.49±0.87kg) were distributed in a completely randomized design with four levels (0, 250, 500, 750mg AOX/kg feed dry matter) and six replicates for a period of 80 days. Cats were induced to stress through the presence of dogs in the experimental environment (stressor agent; AE) from the 61th day to the end. Partial pressure of carbon dioxide (pCO2) and bicarbonate (HCO3) increased linearly (P<0.05) with increased intake of AOX. The highest values of total carbon dioxide (tCO2) (P<0.05) were observed in cats fed the 500 and 750mg AOX/kg diet. Hemoglobin concentration was higher (P<0.05) in animals fed the 250 and 500mg AOX/kg diet. The urinary parameters and EOF were similar among all diets. These data indicate that AOX supplementation has beneficial effects in acid-base balance and hemoglobin concentration of stress-induced cats.(AU)

Punción de la arteria radial guiada por ultrasonido para obtención de gases arteriales / Puncture of the radial artery guided by ultrasound for the obtaining of arterial blood gases

Introducción: La punción de la arteria radial es utilizada para tomar muestras de sangre arterial y realizar exàmentes gasométricos. Es un procedimiento que se realiza de manera frecuente en el área de emergencias, sin embargo, no está exento de complicaciones, por lo que es necesario evaluar técnicas accesorias que permitan reducir los riesgos para el paciente. El objetivo del estudio fue comparar la técnica de punción arterial convencional guiada por palpación con la punción arterial guiada por ultrasonido. Materiales y métodos: Estudio prospectivo en pacientes que ingresaron al Servicio de Emergencia del Hospital Carlos Andrade Marín a quienes se les solicitó gasometría arterial. Para obtener la muestra de sangre arterial se asignó en forma aleatoria a cada paciente a uno de los dos grupos de estudio, el primero en el que se utilizó el método convencional, guiados por palpación y el segundo, guiados por ultrasonido. Los participantes fueron pacientes adultos a quienes se les solicitó gasometría arterial, excluyendo aquellos que tenían alguna contraindicación para el procedimiento. El enrolamiento tuvo lugar en un período de 2 meses. El desenlace primario fue la punción arterial exitosa en el primer intento. Se consideró fracaso, cuando los pacientes requirieron 2 o más punciones para obtener la muestra. Resultados: Noventa y ocho pacientes, fueron enrolados. Cincuenta asignados al grupo guiado por ultrasonido y 48 al grupo control. La punción arterial fue exitosa al primer intento en el 92% del grupo guiado por ultrasonido y 9.6% en el grupo control. El tiempo requerido para obtener la muestra fue similar en los dos grupos (p=0.91). Discusión: La punción arterial guiada por ultrasonido no fue más efectiva que la técnica convencional.

Introduction: Arterial blood gas (ABG) sampling by direct vascular puncture guided by pulse palpation is a common procedure performed in the emergency setting. Reducing the number of attempts to draw arterial blood samples was one of our main goals. The other goal was comparing the standard technique with the ultrasound-guided arterial puncture. Methods: Prospective study in patients admitted to the Emergency Department at Carlos Andrade Marín Hospital, who needed arterial blood gas exams. Patients allocation to draw arterial blood by palpation or guided by ultrasound was chosen at random. Participants were adult patients who needed ABG analysis and excluded patients with any contraindication. The enrollment period lasted two months. The primary endpoint was the successful arterial blood gas sample obtained at first attempt. Failure was taken when patients required more than two punctures to obtain the blood sample. Surrogate endpoint was the amount of time employed in the procedure. Statistical analysis, including Fisher's exact test for categorical variables and independent t-test for quantitative variables, was performed. Results: Ninety-eight patients were enrolled. Fifty were assigned to the ultrasound-guided group and 48 to the control group. The proportion of successful first attempts was 92% in the ultrasound group, and 91.6% in the control group . The amount of time required to draw the blood sample was similar in both groups (p= 0.91). Discusion: Arterial puncture guided by ultrasound was not more effective than the conventional technique to draw arterial blood sample by pulse palpation.

Pain evaluation in newborns using the Neonatal Facial Activity Coding scale during blood gases analysis / Avaliação da dor do recém-nascido através da escala Codificação da Atividade Facial Neonatal durante o exame de gasometria arterial

ABSTRACTBACKGROUND AND OBJECTIVES:This study aimed at evaluating pain of newborns submitted to blood gases analysis by means of the Neonatal Facial Activity Coding scale, as well as at comparing newborns’ physiological parameters before and during arterial puncture.METHODS:This was an exploratory, descriptive and cross-sectional study with 26 newborns submitted to blood gases analysis and admitted to a Neonatal Intensive Care Unit. Data were collected in April and May 2010, by means of an identification form and physiological changes presented by newborns before and during the procedure.RESULTS:There have been newborn facial manifestations of pain (100%), heart rate changes (50%) and decreased oxygen saturation (34.7%).CONCLUSION:When physiological parameters were compared before and during arterial puncture, there have been pain facial manifestations in all newborns as well as physiological changes such as decreased oxygen saturation levels and increased heart rate, according to the Neonatal Facial Activity Coding scale, showing that, although unable to verbalize, newborns are able to show changes expressing the pain felt at arterial puncture. The application of this scale was especially important for favoring sensitization and a holistic nursing care for painful newborns.

RESUMOJUSTIFICATIVA E OBJETIVOS:Avaliar as respostas de dor dos recém-nascidos, submetidos à gasometria arterial, por meio da escala de Codificação da Atividade Facial Neonatal, assim como comparar os parâmetros fisiológicos do recém-nascido, antes e durante a punção arterial.MÉTODOS:Estudo exploratório, descritivo e transversal, que avaliou 26 recém-nascidos em gasometria arterial, internados na Unidade de Terapia Intensiva Neonatal. Os dados foram coletados em abril e maio de 2010, a partir de um formulário de identificação para os recém-nascidos e as alterações fisiológicas apresentadas antes e durante o procedimento.RESULTADOS:Constatou-se presença de manifestações faciais de dor nos recém-nascidos (100%), alteração na frequência cardíaca (50%) e redução da saturação de oxigênio (34,7%).CONCLUSÃO:Quando comparados os parâmetros fisiológicos do recém-nascido, antes e durante a punção arterial, constatou-se que houve presença de manifestações faciais de dor em todos os recém-nascidos e alterações fisiológicas como diminuição dos níveis de saturação de oxigênio e aumento da frequência cardíaca, de acordo com a escala Codificação da Atividade Facial Neonatal, demonstrando que, apesar de não verbalizar, conseguem demonstrar alterações que expressam a dor sentida no momento da realização da punção arterial. A aplicação dessa escala foi importante, especialmente para favorecer a sensibilização e um cuidar de enfermagem holística ao recém-nascido com dor.

Experiencia clínica con el bloqueador bronquial de ARNDT en pacientes pediátricos / Clinical experience with Arndt bronchial blocker in pediatric patients

Describir la experiencia con el bloqueador bronquial de Arndt (BBA) y determinar los efectos de la ventilación monopulmonar (VMP) en el intercambio gaseoso en pacientes pediátricos. Método: El BBA se utilizó en 11 pacientes que requirieron VMP. Cuando el diámetro del tubo traqueal impedía el uso del BBA como originalmente estaba descrito, éste fue colocado en la tráquea previo a la intubación traqueal quedando por fuera del tubo traqueal. El BBA fue posicionado con ayuda de un fibrobroncoscopio introducido a través del adaptador del bloqueador. Se estandarizaron la modalidad deventilación y las maniobras destinadas a restablecer la oxigenación en caso de desaturación. Se controlaron gases arteriales, presión de vía aérea y CO2 de fin de espiración (EtCO2) ventilando ambos pulmones y en VMP. Resultados: El BBA fue correctamente posicionado en todos los pacientes, obteniéndose un pulmón desinflado en todos ellos. La relación pO2 /FiO2 promedio en decúbito lateral ventilando ambos pulmones y en VMP fue 287 (rango 100-424) y 199 (rango 62-332), p = 0,0108. La diferencia pCO2-EtCO2 mostró un comportamiento variable, aumentando en algunos e incluso haciéndose negativa en otros. Conclusión: El BBA permitió realizar VMP en todos los pacientes. La relación paO2/FiO2 disminuyó en todos los pacientes pero la saturación arterial de oxígeno pudo ser mantenida en niveles seguros. La capnografía mostró ser un indicador poco confiable de la efectividad de la ventilación durante VMP...

Single lung ventilation (SLV) and knowledge of its effects in pediatric patients has been limited by the lack of suitable double lumen tubes (DLT). The bronchial blocker (BB) described by Arndt allows SLV without a DLT, even in small children. Objective: Describe the experience with the Arndt’s BB, and the effects of SLV on gas exchange in children. Design: Observational study. Setting and patients: Eleven children requiring SLV using a BB were studied at a University Hospital. Interventions: A BB was used for SLV. When the internal diameter of the ET didn’t allow the use of the BB as originally described, it was inserted into the trachea before tracheal intubation, leaving the BB next to the ET. A FOB inserted through the multi-portal adapter of the BB guided it to the desired position. Ventilatory pattern and maneuvers to restore arterial oxygen saturation (SatO2) were standardized. Main outcome measures: Arterial blood gases, airway pressure, and EtCO2 were obtained in lateral decubitus position while both lungs were ventilated and during SLV. Results: Ages were between seven months and four years. In 10 patients, the BB was inserted alongside the tracheal tube. In all cases the lung was quiet and deflated. In 2 patients, surgical manipulation dislodged the BB. In one it could not be replaced and thoracotomy was required. Arterial pO2decreased in all patients, but SatO2was maintained above 90%. No significant changes in pCO2 and airway pressure were observed, and pCO2 -EtCO2 relationship was unpredictable. Conclusion: Arndt’s BB allowed SLV in all patients. Even though arterial pO2 decreased in all children, SatO2 could be maintained at an acceptable level...

Estado ácido-base en recién nacidos de embarazo con oligohidramnios espontáneo / Acid-base status in newborns from isolated oligohidramnios pregnancies

Objetivo: Relacionar el oligohidramnios aislado con el estado ácido-base del neonato. Materiales y métodos: Se formaron dos grupos, uno de pacientes con oligohidramnios y otro control normal. Se tomó muestra de sangre de la vena umbilical al momento del nacimiento para determinar gases sanguíneos, hemoglobina y hematocrito. Resultados: Los valores promedios al nacer entre casos y controles del pH fue de 7.25±0.07 y de 7.26±0.03, respectivamente; de pCO2 de 50.21±12.1 y 45.63±6.32; de pO2 de 32.60±20.90 y 20.13±8.87; y el HCO3 de 21.34±2.86 y 20.30±2.85. Conclusiones: No hubo diferencias significativas en los valores promedios de pH en sangre del cordón umbilical en embarazos complicados con oligohidramnios; se observó un leve incremento de la pCO2 y compensación con elevación del bicarbonato y excesos de bases. No se demostró una relación directa de oligohidramnios aislado y pobres resultados perinatales.

Objective: To evaluate the relationship of isolated oligohidramnios with the acid-base state of the newborn. Materials and methods: Two groups were formed, one with patients with oligohydramnios and a control group. A blood sample was taken from the umbilical vein at the moment of the birth to determine sanguine gases, hemoglobin and hematocrit. Results: Mean values of the pH at birth were of 7.245±0.074 and of 7.256 ±0.030. The pCO2 had a value of 50.213±12.05 and in control group was 45.626±6.324. The pO2 was of 32.60±20.90 and in the group control was of 20.133±8.871. The HCO3 had a mean value in the group problem of 21.34±2.86, in the group control were of 20.30±2.85. Conclusions: There were not significant differences in the pH mean values in blood of the umbilical cord in complicated pregnancies with oligohydramnios; a light pCO2 increment and compensation with elevation of the bicarbonate and excesses of bases were observed. It was not demonstrated a direct relationship of isolated oligohidramnios and adverse perinatal outcomes.

Gasometría, hematocrito y oximetría de pulso en recién nacidos a 3.600 metros sobre el nivel del mar / Blood gases and hemoglobin at high altitude

La hipoxia secundaria al ambiente -hipobárico de la altura tiene un efecto sobre la saturación arterial de oxígeno. Material y método: se determinó hematocrito y gases sanguíneos en sangre arterial radial derecha de niños sanos de 7 a 14 días de edad, nacidos de madres que cursaron embarazo y parto en la altura (3.600 metros sobre el nivel del mar). Objetivo: determinar saturación arterial de oxígeno en niños sanos de 7 a 14 días de edad, nacidos a 3.600 metros sobre el nivel del mar. Resultados: en una muestra de 60 niños, el hematocrito fue de 50 ± 7,64, similar al encontrado a nivel del mar. La saturación de oxígeno, de 85,34 ± 10,45 comparada con valores de 95 ± 5 encontrados a nivel del mar; es significativamente más baja (p< 0,001) Discusión: se debe tomar en cuenta este valor de referencia de saturación de oxígeno en el tratamiento de niños de edad neonatal en la altura, particularmente si tienen una patología que puede alterar la saturación de oxígeno.

Hypoxia secondary to the hypobaric environment at high altitude has an effect on blood gases. Methods: packed red cell volume (PRC) and blood gases were measured on arterial blood obtained from the right radial artery from healthy children 7 to 14 days old, born of mothers who underwent pregnancy and delivery at high altitude (3,600 meters above sea level). Objective: to determine arterial oxygen saturation in healthy children 7 to 14 days of age, born at 3600 meters above sea level. Results: in a sample of 60 infants, PRC was 50 ± 7,64, similar to the values described at sea level. Oxygen saturation was 85,34 ± 10,45; compared to 95 ± 5 at sea level. The difference was statistically significant (p< 0,001) Discussion: these reference values have to be taken into account when treating young infants at high altitude, particularly those that have an illness that can modify oxygen saturation.

Correlations of Umbilical Venous Erythropoietin and Nucleated Erythrocytes with Blood Gases / 대한산부인과학회잡지

OBJECTIVE: To assess the correlation of erythropoietin(EPO) levels and number of nucleated erythrocytes(NRBC) with measurements of blood gases and to investigate the obstetrical factors influencing the levels of EPO and number of NRBC in umbilical venous blood of non asphyxiated neonates. METHODS: Measurements of EPO levels by RIA, number of NRBC per 100 white blood cells(WBC) by blood smear and measurement blood gases were performed at delivery in umbilical venous blood from 117 cases of neonates with gestational age ranged from 29 to 42 weeks, including 77 cases of non-asphyxia and 40 cases of asphyxia. Statistcial analysis included Student's t test, linear regression and linear correlation using SPSS 7.0 version statistical package. RESULTS: The umbilical venous EPO level is correlated significantly with the number of NRBC (r2 =0.204, p<0.05). The level of EPO as well as the number of NRBC showed inverse correlation with umbilical venous pH(r=-0.223, P<0.05 ; r=-0.896, p<0.05). Number of NRBC showed correlation with pCO2 (r=0.700, P<0.01) and base deficit (r=0.316, p<0.01). The mean level of EPO in non-asphyxiated neonates was 26.2 +/-16.1 mIU/mL showing correlation with gestational age and birth weight and higher level in neonates delivered vaginally than those delivered by elective cesarean section (27.1+/-17.0 vs 18.8+/-6.7 mIU/mL, p=0.012). The mean number of NRBC in non-asphyxiated neonates was 2.5+/-2.1/100 wbc showing no difference according to mode of delivery, gestational age and birth weight. CONCLUSION: Number of NRBC not only correlated with cord gas parameters more strongly but also was less influenced by the obstetrical factors than EPO level.

The Apnea Test for the Determination of Brain Death

By the criteria for the determination of brain deathe established in The Korean Medical Association, an appneic patient's PaCO2 must be greater than 50 torr before apnea can be attributed to brain death. Blood gases were analized in 35cases of brain death by the conventional criteria. The data of PaCO2, pH, PaCO2 in the apnea test of the cases were erratic, but a PaCO2 had increased 50 torr in each patient esaily. To perform the apnea test satisfactorily, it is essential to keep oxygen catheter deep into the tracheal tube by at least 10cm for adequate appneic oxygenation, and indwelling arterial catheters were available for rapid, timed blood sampling. And to determine the accuracy of blood gas measurements, duplicate samples drawn less than 4seconds apart were sent to clinical lagoratory in each test. The apneic test is a crucial rapid and safe performance for the determination of brain death. I recognize.