Control de la ventilación y regulación del estado ácido-base del pez al hombre / Control of ventilation and regulation of acid-base status from fish to man

RESUMEN Este artículo analiza ciertos aspectos evolutivos en el intercambio gaseoso, el desa rrollo pulmonar, la bomba respiratoria, el estado ácido-base y el control de la ventila ción en relación con un evento trascendente: el pasaje de la vida acuática a la terres tre. Su estudio puede permitir comprender ciertos aspectos con los que lidiamos en la práctica clínica: ¿Por qué las personas con debilidad muscular respiratoria extrema respiran como ranas (respiración frog)?, ¿Por qué los recién nacidos con dificultad respiratoria tienen aleteo nasal y quejido espiratorio?, ¿cómo es posible que los mús culos abdominales, típicamente espiratorios, asistan a la inspiración en casos de la parálisis diafragmática?, ¿por qué en la insuficiencia respiratoria el patrón respiratorio tiene menos variabilidad y se torna más rígido? y, por último, ¿es posible imaginar un pH neutro que no tenga el valor de 7,0, para qué sirve este conocimiento y como se deben interpretar los gases en hipotermia? La transición del agua a la tierra es una de las más importantes e inspiradoras de las grandes transiciones en la evolución de los vertebrados. Ante la sorprendente diversi dad de organismos vivos, es tentador imaginar una cantidad enorme de adaptaciones evolutivas para resolver los diferentes desafíos que cada especie tiene para la vida en la tierra. Hay desarrollos tempranos que comparten algunos factores cruciales y algunas de las redes genéticas regulatorias cercanas y lejanas están conservadas. Somos testigos de hallazgos clínicos que son el testimonio de especies que han vivido en épocas remotas y nos han legado su historia evolutiva.

ABSTRACT This article analyzes certain evolutionary aspects of gas exchange, lung development, the respiratory pump, the acid-base status and control of ventilation in relation to a significant event: the passing from aquatic to terrestrial life. By studying this, we can understand certain aspects that are present in the clinical practice: Why do people with extreme respiratory muscle weakness breathe as frogs? (frog breathing); why do newborns with breathing difficulties have nasal flaring and expiratory grunting?; how is it possible that abdominal muscles, which are typically expiratory, assist with inspira tion in cases of diaphragmatic paralysis?; why does the breathing pattern of respiratory failure has less variability and becomes more rigid? and, finally, is it possible to imagine a neutral pH that doesn't have the 7.0 value?; what's the use of this knowledge, and how should gases in hypothermia be interpreted? Water-to-land transition is one of the most important and inspiring major transitions of vertebrate evolution. Given the amazing diversity of living organisms, it is tempting to imagine an enormous amount of evolutionary adaptation processes to solve the different challenges of living on earth faced by each species. There are certain early development processes that share some crucial factors, and some of the close and distant gene regulatory networks are conserved. We are witnesses of clinical findings that serve as testimony of the species that lived in remote times and left us their evo lutionary history.

Physiological variables of the "metabolic component" of acid-base balance and mortality in intensive care patients / Variables fisiológicas del "componente metabólico" del estado ácido base y mortalidad en pacientes de cuidados intensivos

Abstract Introduction: Metabolic acidosis is a frequent pathophysiological condition in critically ill patients. It can be assessed using different physiological variables, but their prognostic value has not yet been well established. Objective: To evaluate the association between the variables that allow assessing the metabolic component of acid-base balance (ABB) and 28-day mortality in patients admitted to an intensive care unit (ICU) in Bogotá, D.C., Colombia. Materials and methods: Prospective cohort study conducted in 122 patients admitted to an ICU between January and June 2013 and with a stay >24 hours. On admission to the ICU, blood samples were taken, and an arterial blood gas test was performed in order to calculate the following variables: anion gap (AG), corrected anion gap (AGc), standard base excess (BEst), metabolic H+, base excess-unmeasurable anions (BEua), arterial pH, arterial lactate, standard HCO3-st, and strong ion difference (SID). APACHE II and SOFA scores were also calculated. A bivariate analysis was performed in which ORs and their respective 95%CI were calculated, and then a multivariate analysis was conducted using a logistic regression model to identify the variables associated with 28-day mortality; a significance level of p<0.05 was considered. Results: Out of the 122 patients, 33 (27.05%) died at 28 days and 51 (48.80%) were women. Participants' mean age was 46.5 years (±15.7). The following variables were significantly associated with 28-day mortality in the bivariate analysis: SID (OR=1.150; p=0.008), BEua (OR=0.897; p=0.023), AG (OR=1.231; p=0.002), AGc (OR=1.232; p=0.003), blood pH (OR=0.001; p=0.023), APACHE II (OR=1.180; p=0.001), HCO3-st (OR=0.841; p=0.015). In the multivariate analysis, only the APACHE II score variable was significantly associated with 28-day mortality (OR=1.188; p=0.008). Conclusion: The physiological variables that allow assessing the metabolic component of ABB, both from the Henderson model and the Stewart model, were not significantly associated with 28-day mortality.

Resumen Introducción. La acidosis metabólica es una condición fisiopatológica frecuente en pacientes críticamente enfermos. Esta alteración es evaluada mediante diferentes variables fisiológicas; sin embargo, su valor pronóstico aún no está bien definido. Objetivo. Evaluar la asociación entre, por una parte, las variables del componente metabólico que permiten valorar el estado ácido base (EAB) y, por la otra, la mortalidad a 28 días en pacientes hospitalizados en una unidad de cuidados intensivos (UCI) en Bogotá D.C., Colombia. Materiales y métodos. Estudio de cohorte prospectivo realizado en 122 pacientes hospitalizados en una UCI entre enero y junio de 2013 y con una estancia mayor a 24 horas. Se tomaron muestras sanguíneas y gases arteriales de ingreso a UCI para el cálculo de las siguientes variables: anion gap (AG), anion gap corregido (AGc), base exceso estándar (BEst), H+ metabólicos, base exceso-aniones no medibles (BEua), pH arterial, lactato arterial, HCO3-st y brecha de iones fuertes (BIF). También se calcularon el puntaje APACHE II y el puntaje SOFA. Se realizó un análisis bivariado en el que se calcularon OR y sus respectivos IC95%, y luego uno multivariado, mediante un modelo de regresión logística, para identificar las variables asociadas con la mortalidad a 28 días; se consideró un nivel de significancia de p<0.05 Resultados. De los 122 pacientes, 33 (27.05%) fallecieron a 28 días y 51 (48.80%) eran mujeres. La edad promedio fue 46.5 años (±15.7). En el análisis bivariado, las siguientes variables se asociaron significativamente con la mortalidad a 28 días: BIF (OR=1.150; p=0.008), BEua (OR=0.897; p=0.023), AG (OR=1.231; p=0.002), AGc (OR=1.232; p=0.003), pH arterial (OR=0.001; p=0.023), APACHE II (OR=1.180;p=0.001), HCO3-st (OR=0.841;p=0.015). En el análisis multivariado, solo el puntaje APACHE II se asoció significativamente con la mortalidad a 28 días (OR=1.188; p=0.008). Conclusión. Las variables fisiológicas que permiten evaluar el componente metabólico del EAB, tanto las del modelo de Henderson, como las del modelo de Stewart, no se asociaron significativamente con la mortalidad a 28 días.

Effects of Plasma-Lyte® and 0. 9% saline in renal function after deceased-donor kidney transplant: a randomized controlled trial

Abstract Background The influence of different crystalloid solutions infused during deceased-donor kidney transplant on the incidence of delayed graft function remains unclear. We investigated the influence of Plasma-Lyte® vs. 0.9% saline on the incidence of delayed graft function in deceased-donor kidney transplant recipients. Methods We conducted a single-blind randomized controlled trial of 104 patients aged 18 to 65 years who underwent deceased-donor kidney transplant under general anesthesia. Patients were randomly assigned to receive either Plasma-Lyte® (n = 52) or 0.9% saline (n = 52), at the same infusion volume, for intraoperative fluid replacement. The primary outcome was the occurrence of delayed graft function. Secondary outcomes included metabolic and electrolytic changes at the end of surgery. Results Two patients in the Plasma-Lyte® group and one in the 0.9% saline group died postoperatively and were not included for analysis. The incidence of delayed graft function in Plasma-Lyte® and 0.9% saline groups were 60.0% (95% Confidence Interval [95% CI 46.2-72.4]) and 74.5% (95% CI 61.1-84.4), respectively (p= 0.140). Mean (standard deviation) values of immediate postoperative pH and serum chloride levels in Plasma-Lyte® and 0.9% saline groups were 7.306 (0.071) and 7.273 (0.061) (p= 0.013), and 99.6 (4.2) mEq.L-1 and 103.3 (5.6) mEq.L-1, respectively (p< 0.001). All other postoperative metabolic and electrolyte variables were not statistically different at the immediate postoperative period (p> 0.05). Conclusion In deceased-donor kidney transplant recipients, the incidence of delayed graft function is not influenced by Plasma-Lyte® or 0.9% saline used for intraoperative fluid replacement.

Princípios analíticos da gasometria arterial / Analytical principles of arterial gasometry

Gasometria arterial (GA) é um exame que permite avaliar a condição respiratória e metabólica do paciente, sendo uma das formas mais comuns de investigação clínica em casos emergenciais e de cuidados críticos. É utilizada para medir as concentrações de oxigênio e também para avaliação do distúrbio do equilíbrio ácido-base, da oxigenação do sangue arterial e da ventilação alveolar. O presente estudo tem como objetivo apontar e avaliar os princípios da técnica de gasometria arterial, fases analíticas, principais doenças em que se utiliza o exame e inovações da técnica ao longo dos anos, baseado em dados de artigos científicos e banco de dados do Scielo (Scientific Eletronic Library Online) e Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde). A coleta de sangue arterial para gasometria ocorre através de um procedimento invasivo realizado por intermédio de uma punção arterial. Tal procedimento é executado pelo profissional enfermeiro e exige qualificações técnicas e científicas. O estudo mostrou que as informações acerca do exame constituem uma importante ferramenta para que se possam compreender a complexidade da técnica bem como os distúrbios ácido-base envolvidos na clínica do paciente.

Arterial blood gas (GA) is an exam that allows the assessment of respiratory and metabolic condition, being one of the most common forms of clinical investigation in emergency cases and critical care. It is used to measure oxygen concentrations, as well as for evaluation of acid-base balance disorder, arterial blood oxygenation and alveolar ventilation. This study aims to point out and evaluate the principles of arterial blood gas technique, analytical phases, main diseases in which the examination is used and innovations of the technique over the years, based on data from scientific articles and SciELO database (Scientific Electronic Library Online) and Lilacs (Latin American and Caribbean Health Sciences Literature). The collection of arterial blood for blood gas analysis occurs through an invasive procedure in which an arterial puncture is performed. Such procedure is performed by the professional nurse and requires technical and scientific qualifications. The study showed that the information about the exam is an important tool to understand the complexity of the technique, as well as the acid-base disorders involved in the patient's clinic.

Distúrbios ácido-base nas doenças hepáticas / Acid-base disorders in liver diseases

O objetivo deste artigo foi abordar as controvérsias científicas acerca dos distúrbios ácido-base nas doenças hepáticas. Nos estágios avançados da doença hepática, os distúrbios ácido-base atuam de forma complexa, comprometendo a qualidade de vida do paciente e desafiando o manejo clínico. A literatura apresenta a alcalose respiratória como uma das principais alterações, porém há uma longa discussão sobre o mecanismo fisiopatológico; em especial, citam-se a hipóxia, a hipocapnia e o nível de progesterona. Nas desordens metabólicas, com destaque para a acidose, os estudos apontam principalmente o lactato, os unmeasured ions ou íons não medidos e as alterações hidroeletrolíticas, mas cada componente desse sobressai-se dependendo da fase da doença estudada, compensada ou descompensada. As controvérsias dos distúrbios ácido-base nas doenças hepáticas devem-se ora à complexidade da fisiopatologia da própria doença, ora à necessidade de mais estudos esclarecedores.

The aim of this study is to address the scientific controversy about acid-base disorders in liver diseases. In the end stage of liver diseases, the acid-base disorder has a complex performance, impairing the patient's quality of life and challenging the clinic management. Although the literature shows respiratory alkalosis as one of the main alterations, there is a long discussion about the pathophysiological mechanism, specially regarding hypoxia, hypocapnia, and progesterone level. In metabolic disorders, especially acidosis, the studies mainly indicate the lactate, unmeasured ions, and hydroelectrolytic alterations, but, depending on the disease phase, either compensated or decompensated, each element has a particular action. The controversy about acid-base disorders in liver diseases is associated with the complexity of this condition, as well as with the necessity of more specialized research.

Comparative analysis of acid-base balance in patients with severe sepsis and septic shock: traditional approach vs. physicochemical approach / Análisis comparativo del equilibrio ácido-base en pacientes con sepsis severa y choque séptico: enfoque tradicional versus enfoque físico-químico

Abstract Introduction: The evaluation of metabolism and the diagnostic classification of acid-base disorders has generated great controversy. Acid-base balance (ABB) is approached by means of the physicochemical and Henderson's models. Objective: To compare two diagnostic approaches to ABB in patients with severe sepsis. Materials and methods: Prospective, descriptive study conducted in patients with severe sepsis. ABB was analyzed within the first 24 hours. The diagnosis was compared according to each model and the causes of the disorders were compared according to the physicochemical model. Results: 38 patients were included in the study, of which 21 (55%) were women; the mean age was 49 years, the median APACHE II, 13.28, and the mortality at 28 days, 24.3%. The traditional approach identified 8 patients with normal ABB, 20 with metabolic acidosis, and 10 with other disorders. Based on the physicochemical model, all subjects had acidosis and metabolic alkalosis. Increased strong ion difference (SID) was the most frequently observed disorder. Conclusion: The physicochemical model was useful to diagnose more patients with acid-base disorders. According to these results, all cases presented with acidosis and metabolic alkalosis; the most frequent proposed mechanism of acidosis was elevated SID. The nature of these disorders and their clinical relevance is yet to be established.

Resumen Introducción. Existe gran controversia en la evaluación del componente metabólico y en la clasificación diagnóstica de las alteraciones del equilibrio ácido-base (EAB), el cual se aborda mediante los modelos físico-químico y de Henderson. Objetivo. Comparar dos enfoques diagnósticos del EAB en pacientes con sepsis severa. Materiales y métodos. Estudio descriptivo prospectivo realizado en pacientes con sepsis severa. Se analizó el EAB en las primeras 24 horas; el diagnóstico se comparó según cada modelo y las causas de alteraciones, según el modelo físico-químico. Resultados. Se analizaron 38 pacientes (55% mujeres) con edad promedio de 49 años, mediana APACHE II de 13 y mortalidad a 28 días del 24.3%. El enfoque tradicional identificó 8 pacientes con EAB normal, 20 con acidosis metabólica y 10 con otros trastornos. En el modelo físico-químico, los 38 pacientes tuvieron alteraciones denominadas acidosis y alcalosis metabólica; el aumento de la brecha de iones fuertes (SIG, por su sigla en inglés) fue la más frecuente. Conclusión. El modelo físico-químico diagnosticó más pacientes con alteraciones ácido-base. Según este, todos tuvieron acidosis y alcalosis metabólica y el mecanismo propuesto más frecuente de acidosis fue el SIG elevado. La naturaleza de estas alteraciones y su significado clínico está por definirse.

Nivel del magnesio sérico y su relación con el medio interno en pacientes incidentes al servicio de emergencia médica de un hospital general / Serum magnesium level and its relationship with internal medium in incident patients attending an emerging service of a public hospital

El magnesio participa en múltiples procesos metabólicos y diversos estudios han mostrado que sus niveles alterados se asocian a enfermedades crónicas, alteraciones del medio interno y en unidades de cuidados críticos, está asociado a mayor mortalidad. Objetivos: Determinar la relación entre el nivel de magnesio sérico y las alteraciones del medio interno, en pacientes incidentes al servicio de emergencia de un hospital general de Lima, Perú. Material y métodos: Se incluyeron 201 pacientes con medida del magnesio, creatinina y electrolitos séricos, así como gasometría arterial al ingreso a emergencia del Hospital Cayetano Heredia (HCH) durante los años 2017-2018. Se analizó los valores del magnesio sérico y su asociación con las demás variables electrolíticas y clínicas. Resultados: La edad media de la población fue 60,1 ± 20,1 años. El magnesio sérico promedio fue 2,05±0,57 mg/dl. La hipomagnesemia e hipermagnesemia tuvieron una frecuencia de 20,4% y 21,9% respectivamente. La regresión lineal bivariado mostró correlación del magnesio con la creatinina, el potasio, el fósforo, el pH y HCO -. En la regresión lineal múltiple, sólo el pH se asoció significativamente con el magnesio. En el análisis del magnesio estratificado, el pH mostró la mayor significancia estadística. No hubo relación con la edad, sexo y variables clínicas. Conclusión: El magnesio es una alteración frecuente en la población que acude a la emergencia del HCH y tiene correlación con el bicarbonato, la creatinina, el potasio, el fósforo y el pH; siendo el último la variable más relevante.

Serum magnesium participates in multiple metabolic processes; several studies have shown that alterations in its serum levels are associated with chronic illnesses, alterations in the internal medium and the critical care units these alterations are associated with higher mortality. Objectives: To determine the relationship between serum magnesium level and alterations in the internal medium in incident patients attending an emerging service of a public hospital. Methods: 201 patients were included who had measurements of serum magnesium, creatinine, serum electrolytes and blood gases on admission to the emergency room at Hospital Cayetano Heredia (CHH) between 2017-2018. Results: Mean age was 60.1 ± 20.1 years. Mean serum magnesium level was 2.05 ± 0.57 mg/dl. Hypo and hypermagnesemia were observed in 20.4% and 21.9%, respectively. Bivariate lineal analysis showed correlation of magnesium with creatinine, potassium, phosphorus, pH and bicarbonate. The multiple lineal regression showed association of magnesium with pH only, which was corroborated in the stratified analysis, no association with age, gender and clinical variables was found. Conclusions: Serum magnesium levels are frequently altered in patients attending the emergency room at CHH and correlates with bicarbonate, creatinine, potassium, phosphorus and pH, with the latter being more relevant.

Gasometría arterial en adultos jóvenes en una altura promedio de 1605 msnm. Armenia, Colombia 2016 / Arterial blood gas in young adults at an average altitude of 1605-m above sea level: Armenia, Colombia 2016

Abstract Introduction: Arterial blood gas measurement is an essential quick test in clinical practice to evaluate oxygenation and for the identification and diagnosis of acid-base and metabolic disorders. Arterial blood gas reference values vary as a result of altitude changes associated with barometric pressure (bp). Objectives: To determine the PaCO2, PaO2, HCO3, and SaO2% values for a young population without lung disease in a city located at an average altitude of 1605-m above sea level and a bp of 624mm Hg. Materials and methods: Descriptive cross-sectional study in 137 arterial blood gas samples from male and female healthy volunteers aged between 18 and 40 years old. An COPD® point of care blood analysis portable system was used for readings with single-use individual cards. Results and conclusion: The 95% confidence interval (CI) limits were pH between 7.43 and 7.45, PaO2 between 86.23 and 88.83, PaCO2 between 32.64 and 33.87, and SatO2% between 97.13 and 97.38. No gender or age differences were found. When comparing the findings against other trials conducted over 2640-m above sea level, some differences were identified: PaO2 between 18 and 26 mm Hg lower at an altitude of 1605 m (Armenia), PCO2 between 2.0 and 2.7 mm Hg higher in Armenia, and also the SaO2% was between 3.6% and 6.2% higher. PaO2 and HCO3~ were mildly higher as compared with a study conducted in Medellin. The oxygenation index (PaO2/FIO2) was 416.83 (95% CI 410.63-23.03)- as expected-considering the difference in altitude due to the geographic location, pursuant to the referenced studies.

Resumen Introducción: La gasometría arterial es una prueba rápida indispensable en la práctica clínica para la evaluación de la oxigenación y para identificar y diagnosticar desórdenes metabólicos, por alteración en el equilibrio ácido base. Los valores de referencia varían por los cambios de altitud relacionados con la presión barométrica (pb). Objetivos: Determinar los valores de PaCO2, PaO2, HCO3- y SaO2% en población joven sin enfermedad pulmonar en una ciudad con altura promedio de 1605 msnm y pb de 624 mmHg. Materiales y métodos: Estudio descriptivo transversal en 137 muestras de sangre arterial de voluntarios sanos de 18 a 40 años ambos sexos. Para la lectura se utilizó un equipo portátil "point of care en sangre EPOC®" con tarjetas individuales de un solo uso. Resultados y conclusiones: Los límites de intervalos de confianza del 95% de las medias fueron: pH entre 7,43 y 7,45; PaO2 86,23 y 88,83; PaCO2 32,64 y 33,87 y SaO2% 97,13 y 97,38. No se encontraron diferencias por sexo ni edad. Al comparar los hallazgos con estudios realizados por encima de los 2640 msnm, se observaron diferencias: PaO2 entre18y 26 mm de Hg menor que a 1605 msnm (Armenia), PCO2 entre 2,0 y 2,7 mm Hg mayor en Armenia al igual que la SaO2% entre 3,6 y 6,2%. La PaO2 y el HCO3- fueron levemente mayores que un estudio realizado en Medellín. El índice de oxigenación (PaO2/FIO2) fue de 416,83 (IC 95% 410,63-423,03), resultados esperados, teniendo en cuenta la diferencia de altura por la ubicación geográfica, según los estudios referenciados.

Serum markers and development of delayed neuropsychological sequelae after acute carbon monoxide poisoning: anion gap, lactate, osmolarity, S100B protein, and interleukin-6

OBJECTIVE: Reliable biomarkers of delayed neuropsychological sequelae (DNS) after acute carbon monoxide (CO) poisoning are lacking. This study investigated the associations between potential serum markers and the development of DNS after acute CO poisoning. METHODS: Retrospective chart reviews were conducted for patients diagnosed with acute CO poisoning during a 28-month period. The patients were divided into two groups according to the presence or absence of having developed DNS. Multivariate analysis was performed to identify predictors of DNS after CO poisoning. RESULTS: Of a total of 102 patients, 10 (9.8%) developed DNS. The levels of serum osmolarity, S100B protein, and serum lactate, as well as serum anion gap, were statistically significant in univariate analysis. Multiple logistic regression analysis showed that anion gap (adjusted odds ratio [AOR], 1.36; 95% confidence interval [CI], 1.11 to 1.88), serum lactate level (AOR, 1.74; 95% CI, 1.26 to 2.75), and serum S100B protein level ([AOR, 7.02×10⁵; 95% CI, 4.56×10² to 9.00×10¹⁰] in model 1, [AOR, 3.69×10⁵; 95% CI, 2.49×10² to 2.71×10¹¹] in model 2) were independently associated with DNS development. CONCLUSION: Based on our preliminary results, serum lactate level, serum anion gap, and serum S100B protein level in the emergency department could be informative predictors of DNS development in patients with acute CO poisoning. These markers might have the potential to improve early recognition of DNS in patients with acute CO poisoning.

Influence of peritoneal lavage with different concentrations of povidone-iodine on hemodynamics and acid-base balance in rabbits / 中华麻醉学杂志

Objective To evaluate the influence of peritoneal lavage with different concentrations of povidone-iodine on hemodynamics and acid-base balance in rabbits.Methods Twenty-four clean-grade healthy adult male New Zealand white rabbits,aged 3 months,weighing 2.8-3.2 kg,were divided into 4 groups (n=6 each) using a random number table:control group (group C),povidone-iodine 1/3 of original concentration group (group TI),povidone-iodine l/2 of original concentration group (group HI) and povidone-iodine of original concentration group (group OI).Rabbits were anaesthetized with intraperitoneal 3％ pentobarbital 1.5 ml/kg,the left femoral artery was cannulated for invasive blood pressure monitoring,and the abdominal cavity was opened.Peritoneal lavage was performed with normal saline,povidone-iodine diluted with normal saline (1 ∶ 2),povidone-iodine diluted with normal saline (1 ∶ 1) and original povidone-iodine 20 ml at 10 min after opening abdominal cavity in C,TI,HI and OI groups,respectively.The fluid for peritoneal lavage was sucked out using a sterile gauze 2 min later and then the abdominal cavity was closed.Mean arterial pressure (MAP) and heart rate (HR) were recorded immediately before lavage (T0) and at 5,10 and 20 min and 1 and 2 h after the end of lavage (T1-5).Arterial blood samples were collected at T0,T4 and T5 for blood gas analysis,and the pH value,BE and lactic acid level were recorded.The duration of anesthesia before peritoneal lavage,cumulative dose of anesthetics,fluid volume and urine volume at 2 h after anesthesia,and mortality at 3 h after peritoneal lavage were recorded.Results Compared with group C,MAP at T1-5 and HR at T3-5 were significantly decreased in TI,HI and OI groups,pH value was significantly decreased and BE negative value was increased at T4,5 in HI and OI groups,the lactic acid level was significantly increased at T5 in group OI,and the mortality rate were significantly increased in HI and OI groups (P＜0.05).Compared with group TI,MAP at T4,5 and pH value at T5 were significantly decreased,BE negative value was increased at T5,and the lactic acid level was increased at T4,5 in group Ol (P＜0.05).There was no significant difference in each parameter between group OI and group HI (P＞0.05).Conclusion Peritoneal lavage with povidone-iodine dose-dependently leads to hemodynamic deterioration and acid-base imbalance in rabbits.

Effects of 37℃ Carbon Dioxide Pneumoperitoneum on Core Body Temperature, Systolic Blood Pressure, Heart Rate and Acid-Base Balance: A Randomized Double-blind Controlled Trial

PURPOSE: The purpose of this study was to compare the effects of 21℃ CO₂ and 37℃ CO₂ pneumoperitoneum on body temperature, blood pressure, heart rate, and acid-base balance. METHODS: Data were collected at a 1300-bed university hospital in Incheon, from February through September 2012. A total of 74 patients who underwent laparoscopic colectomy under general anesthesia with desflurane were randomly allocated to either a control group or an experimental group. The control group received 21℃ CO₂ pneumoperitoneum; the experimental group received 37℃ CO₂ pneumoperitoneum. The pneumoperitoneum of the two groups was under abdominal pressure 15 mmHg. Body temperature, systolic blood pressure, heart rate and acid-base balance were assessed at 30 minutes and 90 minutes after pneumoperitoneum, and again at 30 minutes after arriving at the Post Anesthesia Care Unit. RESULTS: Body temperature in the 37℃ CO2 pneumoperitoneum group was significantly higher (F=9.43, p<.001) compared to the 21℃ CO₂ group. However, there were no statistically significant differences in systolic blood pressure (p=.895), heart rate (p=.340), pH (p=.231), PaCO₂ (p=.490) and HCO3- (p=.768) between the two groups. CONCLUSION: Pneumoperitoneum of 37℃ CO₂ is effective for the increase of body temperature compared to pneumoperitonium of 21℃ CO₂, and it does not result in a decrease of blood pressure, heart rate or acid-base imbalance.

Role of sodium hydrogen exchanger isoform 1 in tumor microenvironment / 国际肿瘤学杂志

The reversed pH gradient across the cell membrane on account of intracellular alkalinization and extracellular acidosis is an importart characteristic of tumor microenvironment.Sodium hydrogen exchanger isoform 1 (NHE1) is ubiquitously expressed at the plasma membrane of many types of cells,which plays a critical role in intracellular pH and cell volume homeostasis.NHE1 plays an important role in the regulation of tumor microenvironment and involves in tumor migration and invasion,which may be a potential new target in anti-cancer therapy.

Estratégias para minimizar os efeitos de um ambiente térmico adverso para frangos de corte / Strategies to minimize the adverse thermal environment in broiler chickens

O calor limita a produção de frangos de corte. Este trabalho avaliou as interações entre o termocondicionamento precoce (TCP) e o uso do equilíbrio eletrolítico (EE) sobre o desempenho e as características da carcaça das aves. Assim, o balanço eletrolítico (BE = Na + K - Cl) foi ajustado em 350mEq/kg, e a relação eletrolítica (K+Cl)/Na em 3:1, pelo programa PPFR. O experimento foi realizado no setor de Zootecnia da Faculdade de Medicina Veterinária de Araçatuba/Unesp. Alojaram-se 240 pintos machos de um dia de idade, linhagem Cobb-500(r), em bateria metálica com 24 divisões e aquecimento elétrico automático. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial 2x2, totalizando quatro tratamentos com seis repetições e 10 aves por parcela experimental. O TCP ocorreu no quinto dia de idade, por 24 horas, a 36,5°C, em metade do lote. Posteriormente, as aves foram transferidas para um galpão climatizado e alojadas em boxes, da mesma forma que a outra parcela que não passou pelo TCP. Avaliaram-se os efeitos do estresse calórico crônico (seis horas a 32°C) aplicado do 35º ao 39º dia de idade. Foram monitoradas a temperatura e a umidade do ar, bem como a temperatura de globo negro. Alimentação e água foram fornecidas ad libitum. Calcularam-se os dados de desempenho zootécnico e a taxa de mortalidade das aves. Submeteram-se os resultados à análise de variância e à comparação de médias pelo teste de Tukey. Não houve interação entre o TCP e o EE sobre o desempenho e as características da carcaça das aves. As estratégias, TCP e EE, mostraram-se ineficazes para amenizar os efeitos do estresse calórico crônico em frangos de corte.

Heat limits the production of broilers. This study evaluated the interactions between early thermal conditioning (ETC) and the electrolyte balance (EB) on performance and characteristics of birds' carcass. Thus, the electrolyte balance (BE = Na+ + K+ - Cl-), was set to 350mEq/kg and electrolyte ratio (K+ + Cl-)/ Na+ in 3:1 by the PPFR program. The experiment was carried out at the Animal Science department of the Faculty of Veterinary Medicine of Araçatuba / UNESP. 240 1 day old Cobb-500(r) male chicks were used, lodged in metal batteries with 24 divisions and automatic electric heating. The experimental design was completely randomized in a 2x2 factorial arrangement, totaling 4 treatments with 6 replicates and 10 birds per experimental plot. ETC occurred on the 5th day of age for 24 hours at 36.5°C in half of the batch. Subsequently, these birds were transferred to an environmentally controlled shed and were grown in boxes, in the same way as the other half that had not received ETC treatment. The effects of chronic heat stress (6 hours at 32°C) applied from the 35th through the 39th day of age were evaluated. Temperature and air humidity, as well black-globe temperature were monitored electronically. Food and water were provided ad libitum. The growth performance data and the mortality rate of birds were measured. The results were subjected to analysis of variance and comparison of means was done by Tukey test. There were no interaction effects between ETC and EB on performance and characteristics of birds' carcass. The ETC and EB strategies proved to be ineffective to mitigate the effects of chronic heat stress in broilers.

Adaptação metabólica diante de hipercapnia persistente aguda em pacientes submetidos à ventilação mecânica por síndrome do desconforto respiratório agudo / Metabolic acid-base adaptation triggered by acute persistent hypercapnia in mechanically ventilated patients with acute respiratory distress syndrome

RESUMO Objetivo: A hipercapnia resultante da ventilação protetora na síndrome do desconforto respiratório agudo desencadeia uma compensação metabólica do pH que ainda não foi completamente caracterizada. Nosso objetivo foi descrever esta compensação metabólica. Métodos: Os dados foram recuperados a partir de uma base de dados registrada de forma prospectiva. Foram obtidas as variáveis dos pacientes no momento da admissão e quando da instalação da hipercapnia até o terceiro dia após sua instalação. Analisamos 41 pacientes com síndrome do desconforto respiratório agudo, incluindo 26 com hipercapnia persistente (pressão parcial de gás carbônico acima de 50mmHg por mais de 24 horas) e 15 sem hipercapnia (Grupo Controle). Para a realização da análise, utilizamos uma abordagem físico-química quantitativa do metabolismo acidobásico. Resultados: As médias de idade dos Grupos com Hipercapnia e Controle foram, respectivamente, de 48 ± 18 anos e 44 ± 14 anos. Após a indução da hipercapnia, o pH diminuiu acentuadamente e melhorou gradualmente nas 72 horas seguintes, de forma coerente com os aumentos observados no excesso de base padrão. A adaptação metabólica acidobásica ocorreu em razão de diminuições do lactato sérico e do strong ion gap e de aumentos na diferença aparente de strong ions inorgânicos. Além do mais, a elevação da diferença aparente de strong ions inorgânicos ocorreu por conta de ligeiros aumentos séricos de sódio, magnésio, potássio e cálcio. O cloreto sérico não diminuiu por até 72 horas após o início da hipercapnia. Conclusão: A adaptação metabólica acidobásica, que é desencadeada pela hipercapnia aguda persistente em pacientes com síndrome do desconforto respiratório agudo, foi complexa. Mais ainda, aumentos mais rápidos no excesso de base padrão em pacientes com hipercapnia envolveram diminuições séricas de lactato e íons não medidos, e aumentos na diferença aparente de strong ions inorgânicos, por meio de ligeiros aumentos séricos de sódio, magnésio, cálcio e potássio. Não ocorreu redução do cloreto sérico.

ABSTRACT Objective: Hypercapnia resulting from protective ventilation in acute respiratory distress syndrome triggers metabolic pH compensation, which is not entirely characterized. We aimed to describe this metabolic compensation. Methods: The data were retrieved from a prospective collected database. Variables from patients' admission and from hypercapnia installation until the third day after installation were gathered. Forty-one patients with acute respiratory distress syndrome were analyzed, including twenty-six with persistent hypercapnia (PaCO2 > 50mmHg > 24 hours) and 15 non-hypercapnic (control group). An acid-base quantitative physicochemical approach was used for the analysis. Results: The mean ages in the hypercapnic and control groups were 48 ± 18 years and 44 ± 14 years, respectively. After the induction of hypercapnia, pH markedly decreased and gradually improved in the ensuing 72 hours, consistent with increases in the standard base excess. The metabolic acid-base adaptation occurred because of decreases in the serum lactate and strong ion gap and increases in the inorganic apparent strong ion difference. Furthermore, the elevation in the inorganic apparent strong ion difference occurred due to slight increases in serum sodium, magnesium, potassium and calcium. Serum chloride did not decrease for up to 72 hours after the initiation of hypercapnia. Conclusion: In this explanatory study, the results indicate that metabolic acid-base adaptation, which is triggered by acute persistent hypercapnia in patients with acute respiratory distress syndrome, is complex. Furthermore, further rapid increases in the standard base excess of hypercapnic patients involve decreases in serum lactate and unmeasured anions and increases in the inorganic apparent strong ion difference by means of slight increases in serum sodium, magnesium, calcium, and potassium. Serum chloride is not reduced.

The Anion Gap is a Predictive Clinical Marker for Death in Patients with Acute Pesticide Intoxication

Pesticide formulation includes solvents (methanol and xylene) and antifreeze (ethylene glycol) whose metabolites are anions such as formic acid, hippuric acid, and oxalate. However, the effect of the anion gap on clinical outcome in acute pesticide intoxication requires clarification. In this prospective study, we compared the anion gap and other parameters between surviving versus deceased patients with acute pesticide intoxication. The following parameters were assessed in 1,058 patients with acute pesticide intoxication: blood chemistry (blood urea nitrogen, creatinine, glucose, lactic acid, liver enzymes, albumin, globulin, and urate), urinalysis (ketone bodies), arterial blood gas analysis, electrolytes (Na+, K+, Cl- HCO3 -, Ca++), pesticide field of use, class, and ingestion amount, clinical outcome (death rate, length of hospital stay, length of intensive care unit stay, and seriousness of toxic symptoms), and the calculated anion gap. Among the 481 patients with a high anion gap, 52.2% had a blood pH in the physiologic range, 35.8% had metabolic acidosis, and 12.1% had acidemia. Age, anion gap, pesticide field of use, pesticide class, seriousness of symptoms (all P < 0.001), and time lag after ingestion (P = 0.048) were significant risk factors for death in univariate analyses. Among these, age, anion gap, and pesticide class were significant risk factors for death in a multiple logistic regression analysis (P < 0.001). In conclusions, high anion gap is a significant risk factor for death, regardless of the accompanying acid-base balance status in patients with acute pesticide intoxication.

Relación del equilibrio ácido-base y supervivencia en adultos con diagnóstico de trauma en la unidad de cuidados intensivos del Hospital Universitario San Jorge. 2009-2010, Pereira, Colombia / Relation of acid-base equilibrium and survival in adults with diagnosis of trauma in intensive care unit in San Jorge University Hospital. 2009-2010, Pereira, Colombia

INTRODUCCIÓN: El trauma es un problema de salud pública en Colombia, siendo la primera causa de mortalidad en jóvenes con una tasa de incidencia de 331,99 casos por 100 000 habitantes, de los cuales aproximadamente el 30% mueren en la unidad de cuidados intensivos. Estos pacientes de acuerdo a su severidad requerirán estabilización de signos vitales y monitoreo estrecho que incluye el estado ácido-base. Objetivo: Establecer la relación entre el desenlace y las variables del estado ácido base de los pacientes con diagnóstico de trauma de la unidad de cuidados intensivos del Hospital Universitario San Jorge de Pereira, Colombia. MATERIALES Y MÉTODOS: Se realizó un estudio tipo cohorte prospectivo en la unidad de cuidados intensivos, en pacientes con diagnóstico de trauma a los que se les tomó muestra de sangre arterial para gases sanguíneos al momento de su ingreso y se monitorearon a través del tiempo hasta el egreso. RESULTADOS: Se incluyeron 38 pacientes con trauma donde el 68,4% fueron hombres. El promedio de edad fue de 35±19 años y el 18,4% de los pacientes que ingresaron fallecieron. Se realizó un análisis univariado, el cual mostró relación individual entre el desenlace y las variables sodio, saturación arterial de oxígeno, presión alveolar de oxígeno y el puntaje de APACHE II; en el modelo de regresión de Cox se encontró relación con las variables presión alveolar de oxígeno, presión arterial de oxígeno, frecuencia cardiaca y relación arterio-alveolar de oxígeno. CONCLUSIÓN: Se encontró que las variables presión alveolar de oxígeno, presión arterial de oxígeno, frecuencia cardiaca y relación arterio-alveolar de oxígeno del análisis de los gases arteriales, tienen correlación con la supervivencia de los pacientes en estado crítico. Se hace una invitación para utilizar este examen paraclínico

INTRODUCTION: Trauma is a public health problem in Colombia and is the first cause of death in young people with an incidence rate of 331.99 cases per 100 000 inhabitants, of which approximately 30% die in the intensive care unit. These patients according to their severity will require stabilization of vital signs and close monitoring which includes the acid-base status. OBJETIVE: To establish the relationship between outcome and variables of acid-base equilibrium of those patients diagnosed with trauma in the intensive care unit of the Hospital Universitario San Jorge in Pereira, Colombia. MATERIALS AND METHODS: A prospective cohort study in type was performed on the intensive care unit with general trauma patients who were taking blood gases on admission to the unit and were monitored over time until discharge. RESULTS: The population of the study were 38 patients with trauma, 68.4% were men. Average age was 35±19 years and 18.4% of patients admitted died. The univariate analysis was found individual relationship with outcome and variables such as sodium, arterial oxygen saturation, alveolar oxygen pressure and APACHE II score. In the Cox regression model it was found a relationship between outcome and variables such as alveolar oxygen pressure, pressure oxygen pressure, heart rate and arterial-alveolar ratio of oxygen. CONCLUSION: Variables found that alveolar oxygen pressure, arterial oxygen pressure, heart rate and arterial-alveolar oxygen ratio of arterial blood gas analysis, correlate with survival of patients in critical condition. An invitation to use this paraclinical test is done

The effect of NaCl 0.9% and NaCl 0.45% on sodium, chloride, and acid-base balance in a PICU population / Efeito do NaCl a 0,9% e do NaCl a 0,45% sobre o sódio, cloreto e equilíbrio ácido-base em uma população de UTIP

ABSTRACT OBJECTIVES: To study the effect of two intravenous maintenance fluids on plasma sodium (Na), and acid-base balance in pediatric intensive care patients during the first 24 h of hospitalization. METHODS: A prospective randomized controlled study was performed, which allocated 233 patients to groups: (A) NaCl 0.9% or (B) NaCl 0.45%. Patients were aged 1 day to 18 years, had normal electrolyte concentrations, and suffered an acute insult (medical/surgical). Main outcome measured: change in plasma sodium. Parametric tests: t-tests, ANOVA, X 2 statistical significance level was set at a = 0.05. RESULTS: Group A (n = 130): serum Na increased by 2.91 (±3.9) mmol/L at 24 h (p < 0.01); 2% patients had Na higher than 150 mmol/L. Mean urinary Na: 106.6 (±56.8) mmol/L. No change in pH at 0 and 24 h. Group B (n = 103): serum Na did not display statistically significant changes. Fifteen percent of the patients had Na < 135 mmol/L at 24 h. The two fluids had different effects on respiratory and post-operative situations. CONCLUSIONS: The use of saline 0.9% was associated with a lower incidence of electrolyte disturbances.

RESUMO OBJETIVO: Estudar o efeito de dois fluidos de manutenção intravenosos sobre o sódio (Na) plasmático e o equilíbrio ácido-base em pacientes de terapia intensiva pediátrica durante as primeiras 24 horas de internação. MÉTODOS: Foi feito um estudo controlado randomizado prospectivo. Alocamos aleatoriamente 233 pacientes para os grupos: (A) NaCl a 0,9% e (B) NaCl a 0,45%. Os pacientes com um dia a 18 anos apresentavam concentrações normais de eletrólitos e sofriam de insulto agudo (médico/cirúrgico). Principal resultado: variação no sódio plasmático. Testes paramétricos: teste t, Anova, qui-quadrado. O nível de relevância estatística foi estabelecido em a = 0,05. RESULTADOS: Grupo A (n = 130): o Na sérico aumentou 2,91 (± 3,9) mmol L-1 em 24 h (p < 0,01); 2% dos pacientes apresentaram Na acima de 150 mmol L-1. Concentração média de Na na urina: 106,6 (± 56,8) mmol L-1. Sem alteração no pH em 0 e 24 horas. Grupo B (n = 103): o Na sérico não apresentou alterações estatisticamente significativas; 15% dos pacientes apresentaram Na < 135 mmol L-1 em 24 h. Os dois fluidos tiveram efeitos diferentes sobre as situações respiratória e pós-operatória. CONCLUSÃO: O uso de solução fisiológica a 0,9% foi associado à menor incidência de distúrbios eletrolíticos.

¿Es la diferencia de aniones fuertes un buen marcador de mortalidad en adultos con abdomen en tabla? / Is the Strong Anion Gap a good marker of mortality in the adult with acute abdomen?

Introducción. Tradicionalmente, el ácido láctico, la proteína C reactiva y el déficit efectivo de base, se han utilizado para predecir la mortalidad en pacientes críticamente enfermos. La información es insuficiente cuando se utiliza la diferencia de aniones fuertes. En especial, no existen datos de pacientes con abdomen agudo. El objetivo de este estudio piloto fue evaluar el desempeño de la diferencia de aniones fuertes para predecir la mortalidad perioperatoria (30 días) en pacientes con abdomen en tabla, que requieren cirugía inmediata, en comparación con el ácido láctico, el déficit efectivo de base, la albúmina y la relación proteína C reactiva/albúmina. Materiales y métodos. Para evaluar las características operativas de cada uno de los factores metabólicos en relación con la mortalidad periperatoria temprana, se determinó el área bajo la curva ROC (Receiver Operating Characteristics). Una vez obtenidos los mejores puntos de corte, se evaluó la asociación entre los sobrevivientes y los no sobrevivientes, mediante la prueba de ji al cuadrado (p<0,05). Resultados. Entre los factores metabólicos analizados, los que presentaron una mejor área bajo la curva ROC, fueron el ácido láctico (0,85) y el déficit efectivo de base (0,71). El área bajo la curva de la diferencia de aniones fuertes fue inferior (0,68), así como la de la diferencia aparente (0,68) y la diferencia efectiva (0,60). La relación proteína C reactiva/albúmina mayor de 5.000 g/L demostró un área bajo la curva ROC de 0,63. Se demostró diferencia estadística para el ácido láctico por encima de 4 mmol/L, la diferencia aparente de aniones fuertes menor de 40 mmol/L, la diferencia de aniones fuertes mayor de14 mmol/L y el déficit efectivo de base mayor de 7 mmol (p<0,05), entre sobrevivientes y no sobrevivientes. Conclusión. La diferencia de aniones fuertes (fuerte, aparente y efectiva) demuestra menores características operativas en pacientes con abdomen en tabla, cuando se correlaciona con la mortalidad posoperatoria temprana, en comparación con el ácido láctico y el déficit efectivo de base. La relación proteína C reactiva/albúmina demuestra mejores características operativas que la diferencia de aniones fuertes y debe evaluarse en nuevos estudios.

Background: Historically, the lactic acid, C- reactive protein and the Base Deficit, have been used to predict mortality in critical ill patients. Bu the information is not sufficient about the Strong Ion Gap (SIG) or Strong Ion Gap Difference (SID) as predictor. As a matter of fact, there is no information available for patients with acute abdomen. The objective for this study was to evaluate the performance of SID as a predictor of perioperative mortality (30 days) in patients with acute abdomen requiring immediate surgery, in comparison with serum levels of lactic acid, base deficit, albumin, and the C- reactive protein (CRP) / albumin ratio. Methods: In order to evaluate the operative characteristics of each one of the metabolic factors related to the early perioperative mortality, an area under an ROC curve (Receiver Operating Curve) was determined. Once the best cutting points were obtained, the association between survivors and not survivors was evaluated using the Chi square test (p<0.05). Results: Once analyzed the metabolic factors, those who presented a better area under the ROC curve were lactic acid (0.85) and base deficit (0.71). The area under an ROC curve of the SID was inferior (0.68), as well as the apparent strong ion gap (SIDa) (0.68) and the Effective Strong Ion Gap (SIGe) (0.60). The RCP/albumin ratio was higher than 5000 m/l with an area under an ROC curve of 0.63. There is statistically difference over 4 mmol/L for lactic acid, below 40 mmol/L for SIDa, higher than 14 mmol/L for SID and higher than 7 mmol for base deficit ( p<0.05), between survivors and not survivors. Conclusion: The Strong Ion Gap Difference (apparent and effective) shows less operative characteristics in patients with acute abdomen, when it is correlated with early postoperative mortality, in comparison with the lactic acid and the base deficit. The RCP/ albumin demonstrate better operative characteristics than the SID, and it must be evaluated in new studies.

Unmeasured anions as predictors of mortality in medical intensive care unit / Ânions não mensuráveis podem predizer mortalidade em unidade de terapia intensiva clínica

BACKGROUND AND OBJECTIVE: The present study aimed to evaluate the utility of variables that represent unmeasured anions (anion gap, anion gap corrected for albumin, anion gap corrected for albumin and lactate, base excess and modified base excess) to predict mortality in medical intensive care unit patients. METHODS: This prospective study included 156 con secutive patients admitted to a medical intensive care unit in a Medical school hospital between August 2006 and June 2007. Serum levels of potassium, sodium, chloride, C-reactive protein, albumin, and lactate were measured. Variables that re- present unmeasured anions and APACHE II score were calcula- ted. RESULTS: Among the studied patients, 60.9% were male, and mean age was 59.2±17.2 years. Mortality rate was 31.4%. Spearman?s test showed correlation among unmeasured anions and lactate. Comparison between survivors and non-survivors showed differences in length of intensive care unit stay, APACHE II score, albumin, C-reactive protein, lactate, anion gap corrected for albumin, base excess, and modified base excess. Anion gap corrected for albumin, base excess, and modified base excess are predictors of medical intensive care unit mortality; however, theirs areas under the ROC curves are smaller than APACHE II score and C-reactive protein. CONCLUSION: Variables that estimate unmeasured anions, such as anion gap corrected for albumin, base excess, and modified base excess, can be used to predict mortality in medical intensive care unit patients.(AU)

JUSTIFICATIVA E OBJETIVO: O presente estudo teve como objetivo avaliar a utilidade de variáveis que representam ânions não mensuráveis (ânion gap, ânion gap corrigido para a al- bumina, ânion gap corrigido para a albumina e lactato, excesso de base e excesso de base modificado) para prever a mortalidade em pacientes de unidade de terapia intensiva. MÉTODOS: Foram incluídos 156 pacientes consecutivos admitidos na unidade de terapia intensiva em um hospital escola de Medicina entre agosto de 2006 e junho de 2007. Os níveis séricos de potássio, sódio, cloreto, proteina C-reativa, albumina e lactato fo ram medidos. Foram calculadas variáveis que representaram os ânions não mensuráveis e APACHE II. RESULTADOS: Entre os pacientes estudados, 60,9% eram do sexo masculino, e a idade média foi de 59,2±17,2 anos. A taxa de mortalidade foi de 31,4%. O teste de Spearman mostrou correlação entre ânions não mensuráveis e lactato. A comparação entre sobreviventes e não sobreviventes mostrou diferenças no tempo de permanência na unidade de terapia intensiva, APACHE II, albumina, proteína C-reativa, lactato, ânion gap corrigido para a albumina, excesso de base e excesso de base modificado. Ânion gap corrigido para a albumina, excesso de base e excesso de base modificado foram preditores de mortalidade na unidade de terapia intensiva médica, mas as áreas sob as curvas ROC foram menores do que o escore APACHE II e a proteína C-reativa. CONCLUSÃO: Variáveis que estimam ânions não mensuráveis, como o ânion gap corrigido para a albumina, o excesso de base e o excesso de base modificado, podem ser usados para prever a mortalidade em pacientes em unidade de terapia intensiva clínica.(AU)

Impact of different irrigation time on oxygenation index and acid-base balance during percutaneous neph-rolithotomy / 临床麻醉学杂志

Objective To investigate the impact of different irrigation time on oxygenation in-dex and acid-base balance during percutaneous nephrolithotomy(PCNL).Methods Forty patients un-dergoing selective PCNL were included in this study,were divided into two groups:group S,irrigation time<120 min(n=22);group L,irrigation time≥120 min(n=18).PaO2/FiO2 ,pH and BE were determined before and after irrigation,CVP were recorded before irrigation and every 20 min during irrigation. Results The CVP maximum value were higher in group L than that in group S during irrigation (P <0.05).The PaO2/FiO2 were lower after irrigation than that before irrigation in group L(P<0.05).The pH and BE were lower in group L than that in group S after irrigation(P<0.05).Conclusion Irrigation fluid absorption is observed during PCNL.That can provoke oxygenation function decline and metabolic ac-idosis with irrigation time extend,the operation time properly shortened.