[Regional cerebral oxygen saturation as a marker of hemodynamic state following cardiac surgery]. / Saturación cerebral de oxígeno como marcador hemodinámico en la cirugía cardíaca.

INTRODUCTION: Regional cerebral oxygen saturation (rSO2) is a measure of the general state of perfusion and oxygenation. We aim to analyze the relationship between this and various hemodynamic and respiratory parameters. PATIENTS AND METHODS: Forty-three patients, operated on between October 2011 and July 2012, were included in this prospective observational descriptive study. The following parameters were measured: mean arterial pressure, both arterial and central venous oxygen saturation and partial pressures of oxygen and carbon dioxide, and lactate levels. From these parameters, the oxygenation index and the oxygen extraction ratio were calculated. These measurements were studied to evaluate whether rSO2 correlated significantly with the other parameters. RESULTS: The average age and weight of the patients were 27.3 months and 9.2 kg, respectively. The rSO2 correlated positively with both central venous oxygen saturation (r=0.73, P<.01) and mean arterial pressure (r=0.59, P<.01), and negatively with the oxygen extraction ratio (r=-0.7, P<.01). No correlation was found with the respiratory parameters. Concordance analysis established an acceptable Kappa index (> 0.4) between the rSO2 and central venous oxygen saturation, and between the rSO2 and oxygen extraction ratio. CONCLUSIONS: Regional cerebral oxygen saturation correlates well with hemodynamic parameters - mean arterial pressure, venous saturation, and the tissue oxygen extraction. However, it does not correlate with respiratory parameters.

[Oxygen extraction as a predictor of mortality in patients on high frequency ventilation]. / Extracción de oxígeno como predictor de mortalidad en pacientes con ventilación de alta frecuencia.

INTRODUCTION: The high frequency oscillatory ventilation (HFOV) may reduce cardiac output. The haemodynamics were analysed and predictors of mortality identified. PATIENTS AND METHODS: A total of 48 children with respiratory failure undergoing HFOV between January 2003 and December 2010 were included. The study design was prospective, observational, and descriptive. Inclusion criteria were based on the existence of hypoxemia. The variables studied were: arterial and central venous pressure, arterial pH, venous saturation and oxygen extraction ratio, with determinations performed prior to HFOV, during, and before turning to conventional ventilation. Prognostic factors were identified by bivariate analysis and a predictive model of mortality was developed. RESULTS: The mean age was 21 [4 to 72] months. On admission, PRISM scales and Murray were 33 and 2.8, PaO(2)/FiO(2) of 61 and oxygenation index of 35. After HFOV an increase in pH (P<.001), mean arterial pressure (P<.001) and venous saturation, and decreased venous pressure and O(2) extraction (P<.001), was obtained. The prognostic factors of mortality at 24 hours after starting HFOV were: FiO(2), PaO(2)/FiO(2), oxygenation index, shunt, pH, central venous pressure and mean arterial pressure, venous saturation, and O(2) extraction. The model developed at 12 hours, consisting of EtO(2) and SvcO(2) was able to predict death with a probability of 92.3%. CONCLUSIONS: HFOV improves haemodynamics. The model at 12 hours is the best predictor of death.

[Prognostic markers of mortality after congenital heart defect surgery]. / Marcadores pronósticos de mortalidad en el postoperatorio de las cardiopatías congénitas.

INTRODUCTION: Our aim is to identify risk factors for mortality after surgery for congenital heart disease in children, in order to establish indications for extracorporeal membrane oxygenation (ECMO). PATIENTS AND METHODS: One hundred and eighty six children underwent cardiac surgery with extracorporeal circulation from April 2007 to June 2009. The following parameters were measured serially during their stay in Paediatric Intensive Care (PICU): Arterial and venous blood pH, pCO2, base excess, oxygen saturation, arterio-venous oxygen saturation difference, oxygen extraction ratio, ventilatory dead space and intrapulmonary shunting. RESULTS: Hospital mortality was 13,4%. The following risk factors for mortality were identified: age, bypass time, inotropic score, lactate level upon arrival in PICU including its peak value and its rate of variation, mixed venous saturation, base excess, ventilatory dead space, oxygen extraction ratio, and intrapulmonary shunting. However, the strongest predictors of mortality were bypass time, lactate levels upon admission on PICU, and the peak lactate level. Multivariate analysis showed a lactate level of 6.3mmol/l and a high blood lactate for 24hours to be independent predictors of mortality. CONCLUSIONS: The peak lactate level is a strong predictor of mortality. As such, it would be a useful indicator of the need for ECMO support.

[Prognostic evaluation of arterial switch in the transposition of great arteries]. / Valoración pronóstica del switch arterial en la transposición de grandes arterias.

INTRODUCTION AND OBJECTIVES: The arterial switch is the procedure of choice for transposition of great arteries, with or without ventricular septal defect. The aim of this study was to identify risk factors for hospital mortality. METHODS: The study included 121 children between January 1994 and June 2008. Of these, 80 (66%) were diagnosed with intact ventricular septum, and 41 (34%) with ventricular septal defect. Variables were collected pre-operatively, during surgery, and postoperatively. RESULTS: The mean age was 11 [8 to 16] days and a mean weight of 3.5 [3.0 to 3.7] kg. A ventricular septal defect was closed in 11 children (9.1%). A total of 81.8% had a normal coronary pattern. There was delayed closure of the chest in 38 patients (31.4%). The hospital mortality was 11.6%, decreasing over the past 5 years to 2.1%. The weight, abnormal coronary pattern, time of cardiopulmonary bypass, mean arterial pressure at admission, pulmonary dead space, and delayed closure of the chest, were risk factors of mortality. The model that best predicts death, consists of the mean arterial pressure at admission, and delayed closure of the chest. CONCLUSIONS: The reduction in extracorporeal circulation time and the use of delayed closure of the chest, have helped to reduce mortality. The abnormal coronary pattern remains a risk factor for mortality. In children with delayed closure of the chest, a mean arterial pressure at admission ≥ 47.5 mmHg is a goal to achieve.

[High-frequency oscillatory ventilation. A single-center study]. / Nuestra experiencia con la ventilación de alta frecuencia oscilatoria.

INTRODUCTION: High-frequency oscillatory ventilation is a safe and effective means of delivering mechanical ventilatory support. OBJECTIVE: To evaluate the safety and effectiveness of high-frequency oscillatory ventilation in pediatric patients with acute respiratory failure. PATIENTS AND METHOD: From August 2003 to July 2005, we performed a prospective observational study of 11 children older than 1 month who underwent high-frequency oscillatory ventilation. Pediatric risk of mortality scores (PRISM), Murray lung-injury scores and air leak scores were recorded at baseline before ventilation. The following variables were studied: ventilatory settings (FiO2 and mean airway pressure), gasometric (PaO2, SaO2, PaCO2, pHa, PaO2/FiO2 ratio) and hemodynamic parameters (Partm, PVC), and the oxygenation index. RESULTS: The overall survival rate was 82 %. Significant increases were found in PaO2 (p < 0.05), SaO2 (p < 0.05) and the PaO2/FiO2 ratio (p < 0.05), while mean airway pressure (p < 0.001), oxygenation index (p < 0.001), and FiO2 (p < 0.001) significantly decreased over time. CONCLUSIONS: High-frequency oscillatory ventilation significantly improved oxygenation in children with acute hypoxemic respiratory failure.

[Meningococcal sepsis in our area. Study of the disease severity factors and therapeutic management over a 10-year period]. / La sepsis meningocócica en nuestro medio. Estudio de los factores de gravedad del proceso y de la actitud terapéutica durante 10 años.

Meningococcal sepsis with cardiovascular manifestations is one of the leading causes of pediatric intensive care admission (14.85%) in our area. We carried out a two phase study over period of 10 years from 1979 to 1988, involving a retrospective analysis of clinical and analytical manifestations in order to determine a prognostic score of the severity of meningococcal infections in our area. A total of 86 cases were studies over a two year period. After establishing the prognostic score, we applied a previously assayed therapeutic protocol, based on the number of criteria of severity, in 170 children selected as having the same criteria. The factors of seriousness considered were: Appearance of the first symptoms less than 12 h. previously, appearance of petechia less than 6 h. previously, hyperthermia, shock at admission, absence of meningitis, fulminating course of purpura and convulsions, leukopenia less than or equal to 5,000 mm3, prothrombin activity less than or equal to 45%, platelets less than or equal to 75,000 mm3, fibrinogen less than or equal to 250 mgrs% and FPD greater than 40 micrograms/ml (p less than or equal to 0.01 (CHI SQUARE]. In the first phase of study, overall mortality was associated with the presence of three criteria, and was highest when more than seven criteria were present. The results indicate that mortality from meningococcal sepsis is linked to fulminating deterioration of hemodynamics and DIC.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studying the levels of endotoxemia in meningococcal sepsis. Its relations to pregnancy and antibiotic treatment]. / Estudio de los niveles de endotoxemia en las sepsis meningococias. Su relación con la gravedad del proceso y el tratamiento antibiótico.

The most frequent cause of toxic shock in our area is meningococcal sepsis. It is currently assumed that endotoxin produce by this bacteria, a lipopolysaccharide with toxic properties, is able to trigger shock and DIC by stimulating both arachidonic acid pathways, among other actions. Previous studies in our laboratory demonstrated significant differences (p +/- 0.001) in the amounts of endotoxins released in vitro by strains from patients and healthy carriers and statistically related criteria of severity with mortality in 256 patients in our center over the last 10 years. In the present study we attempted to establish whether plasma levels of endotoxin were correlated with the severity of the disease. We studied 32 patients with meningococcal sepsis, dividing the subjects into two groups: those in whom six or more criteria of severity were present, and those in whom less than six criteria were found. Blood levels of endotoxin were determined upon admission and after the administration of antibiotics (penicillin and chloramphenicol) using the limulus test with a chromogenic substrate (Coatest, Endotoxin, Kabivitrum, Sweden). Levels of endotoxins were significantly higher in patients with more than six criteria of severity both upon admission (0.6 +/- 0.03) ng/ml) and 4 h. afterward (0.74 +/- 0.006 ng/ml) in comparison to children in whom the clinical picture was less serious (0.27 +/- 0.18 ng/ml and 0.27 +/- 0.18 ng/ml and 0.27 +/- 0.16 ng/ml7 t = 5.8 y t = 5.6 respectively. Endotoxin levels were highest in patients presenting shock, disseminated intravascular coagulation in the hypocoagulability phase and more than 8 criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

[Plasma concentration of atrial natriuretic peptide, vasopressin and aldosterone in the umbilical cord blood: its relation to perinatal asphyxia]. / Concentraciones plasmáticas de péptido natriurético atrial, vasopresina y aldosterona en sangre de cordón umbilical: sus relaciones con la asfixia perinatal.

Aldosterone, vasopressin (AVP) and atrial natriuretic factor (ANF) plasmatic concentrations were determined in cord arterial blood from 42 newborns to term: 29 healthful and 13 with perinatal asphyxia. Control group showed plasmatic levels (pg/dl) AVP, aldosterone and ANF significantly lower than perinatal asphyxia newborns group (AVP: 2.27 +/- 1.43 vs 4.26 +/- 2.86; aldosterone: 1.113 +/- 384.79 vs 1,540.38 +/- 595.96; ANF: 2.27 +/- 1.43 vs 4.26 +/- 2.86, respectively (p less than 0.05). We found an inverse correlation between umbilical arterial pH vs AVP, aldosterone and AFN, and a direct correlation between ANF vs aldosterone. Perinatal asphyxia induces secretion of the three studied hormonal factors, likely as a physiologic mechanism of fetal adaptation to hydroelectrolytic and hemodynamic changes which occur during the asphyxia.

[PGE and PGF2-alpha levels in the umbilical cord vessels. Relationship to acid-base equilibrium in the umbilical artery]. / Niveles de PGE y PGF2-alfa en los vasos del cordón umbilical. Su relación con el equilibrio ácido-base de la arteria umbilical.

To asses the possible role of prostaglandins in the fetoplacental circulation during delivery PGE and PGF2-alfa plasma levels were measured in the umbilical vessels of term newborns. The levels of PGF2-alfa in blood from the umbilical vein are significantly higher and more variable than in the umbilical artery; 83.38 +/- 78.05 pg/ml versus 43.28 +/- 5.32 pg/ml. PGE levels are also higher in the vein 114.73 +/- 25.16 pg/ml than in the artery 83.63 +/- 9.22 pg/ml. There was a statistically significant negative correlation between the arterial pH and PGE in the umbilical vein these results support the idea that the plasmatic umbilical prostaglandins are synthetized by the placenta the variability in the values obtained in venous umbilical blood may reflect the different times of ligation of the umbilical cord. A decrease in fetal pH may be the stimulus for the prostaglandin synthesis by the placenta.

[Importance of the function of polymorphonuclear neutrophils in intrinsic and extrinsic asthma. Interaction of whole serum in the control of cellular activity]. / Importancia de la función de los polimorfonucleares neutrófilos en el asma intrínseco y extrínseco. Interacción del suero total en el control de la actividad celular.

A study was made of polynuclear leucocyte function: chemotaxis, NBT reduction and the influence of total plasma on chemotaxis, was investigated in a large group of asthmatic paediatric patients, both during and between asthmatic attacks. It has been proved that polynuclear function is different in the two types of asthma. During the asthmatic's crisis and in the intrinsic patients in intercrisis periods, there is a polynuclear neutrophil hyperreaction when the chemotaxis and the NBT reduction are raised. An inhibited chemotactic activity in the plasma of these patients is noted. This activity doesn't produce irreversible effects on the cells; it acts as a regulating mechanism on the chemotactic factors found in plasmatic fractions.

[Osmolarity and arginine-vasopressin in children born after acute fetal-neonatal distress]. / Control osmolar y arginina vasopresina en niños nacidos después de un sufrimiento fetoneonatal agudo.

A study of urinary osmolarities and plasmatic level of arginine-vasopressin (AVP) 48 hours after birth in a group of 70 newborns (30 of which are normal and 40 of which have acute perinatal hypoxia), selected according to previously established criteria is carried out. An evolutionary study of urinary osmolarities of newborns with acute perinatal hypoxia, osmolar index and its relation to plasmatic levels of AVP during the first week of life is also considered. AVP 48 hours after birth was blatantly more elevated among those newborns who had shown acidosis at birth (p less than 0.001) which correlated significantly with urinary osmolarity, although it showed low figures (p less than 0.05). This same correlation (p less than 0.001 and p less than 0.05) appears with osmolar index and urinary osmolarity on successive days, but it is important to point out that vasopressin decreased to base values at the end of the first week of life while osmolarities in urine increased. Conclusions are: 1) AVP is higher after 48 hours of life among those newborns with acute perinatal hypoxia and decreases progressively during the first week of life, being comparable to values obtained from normally born children 48 hours after birth at the eight day of life. 2) Renal response to this hormone is slight during the first days of life.