[Acute infarction of the right ventricle. Physiopathology, treatment, and prognosis]. / Infarto agudo del ventrículo derecho. Fisiopatología-tratamiento y pronóstico.

A revision of the pathophysiology clinical classification and treatment of the right ventricular infarction (RVI) is presented. For many years it was believed that right ventricular (RV) contraction was neither important nor crucial to the maintenance of systemic circulation. Although non-invasive studies have reported RV dilation and RV wall motion abnormalities in 50% of patients with inferior--posterior--left ventricular myocardial infarction, RV involvement leads to significant hemodynamic compromise in less than half of such cases. When RVI patients are identified, they should be classified in those without RV failure (Class A), those with RV failure (Class B) and those with shock (Class C). Concerning the role of reperfusion therapies, both therapies (TT or PCI) seem beneficial, because a trend in the reduction of mortality has been observed. A decrease in RV failure was noted in class B patients, and PCI appears to be the procedure of choice in class C patients, since it significantly reduced mortality.

[Prevalence of nosocomial infections in children: survey of 21 hospitals in Mexico]. / Prevalencia de infecciones nosocomiales en niños: encuesta de 21 hospitales en México.

OBJECTIVE: The purpose of this study was to determine the prevalence of nosocomial infections, associated risk factors, microbiology, use of antibiotics, and associated mortality among hospitalized children. MATERIAL AND METHODS: A 1-day prevalence survey was conducted among 1,183 children hospitalized in a nationwide network of 21 public hospitals caring for children. To attain consistency between hospitals, CDC nosocomial infection definitions were used. Adjusted relative odds of bacteremia were estimated using logistic regression analysis. RESULTS: The prevalence of nosocomial acquired infection was 9.8% (CI 95%, 8.1-11.6). The more prevalent infections were pneumonia (25%), sepsis/bacteremia (19%), and urinary tract infection (5%). The main microorganism isolated in blood cultures drown from patients with nosocomial infection was K. pneumoniae (31%). The prevalence of antibiotics use was 49% with substantial variation between hospitals (range 3-83%). Using logistic regression analysis, four factors were independently associated with the risk of nosocomial infection: central venous catheters (OR 3.3; CI 95% 1.0-5.9), total parenteral nutrition (OR 2.1; CI 95% 1.0-4.5) mechanical ventilation (OR 2.3; CI 95% 1.2-4.1), and low birth weight (OR 2.6; CI 95% 1.0-6.8). The overall mortality was 4.8%; however, patients with nosocomial infection had two times greater risk to die as compared to non-infected children (OR 2.6; CI 95% 1.3-5.1). CONCLUSIONS: This rapid assessment survey using a standard methodology allows to document the prevalence of nosocomial infections in children. The results were used to develop targeted programs on central catheters and mechanical ventilation aimed to reduce bacteremia/sepsis and pneumonia, two nosocomial infections characterized by high prevalence and mortality.

[The utility of rapid qualitative determination of troponin T, the MB fraction of creatine phosphokinase and myoglobin in acute ischemic coronary syndromes]. / Utilidad de la determinación cualitativa rápida de troponina-T, fracción MB de creatina fosfocinasa y mioglobina en los síndromes isquémicos coronarios agudos.

The objective of our study was to validate the diagnostic utility of cardiac troponine T in acute ischemic syndromes, and also in cases of difficult diagnosis. We analyzed its concordance and compare them with conventional enzymatic quantitative methods. We determined sensitivity, specificity, positive and negative predictive values and likelihood ratio. Kappa index was used to know the concordance grade between T troponin and the positive or negative results of the quantitative enzymatic curve. Stochastic significance was valued by Chi square of Mcnemar test. In seventy patients who arrived to the hospital with chest pain who were assigned to five different groups. The sensitivity in quantitative markers was higher than qualitative methods, however the specificity, likelihood ratio was lower. In the total group the concordance analysis between qualitative and quantitative markers was adequate, (kappa index 0.65 p < 0.05). This study suggest that the rapid bedside qualitative test by cardiac Troponin T is a good diagnostic marker compared with conventional quantitative markers to evaluate chest pain in acute ischemic syndromes.

[Effect of chronic altitude hypoxia on the behavior of the respiratory center. Study on normal subjects living at the altitude of Mexico City (2,240 meters)]. / Efecto de la hipoxia crónica de la altitud en el comportamiento del centro respiratorio. Estudio en sujetos normales residentes a la altitud de la ciudad de México, D.F. (2,240 mts).

Respiratory center (RC) output has been shown to be increased in hypoxemic Chronic Obstructive patients at sea level. In order to asses the separate role of chronic hypoxia on the RC output we studied 30 normal subjects all of them native and residents of Mexico City (altitude: 2,240 m, PaO2: 65-70 torr.). The parameters studied were: occlussion pressure (P0.1), mean inspiratory flow (Vi), and the ratio inspiratory time to total duration of the respiratory cycle (Ti/Ttot). The inspiratory impedance of the respiratory system as well as the minute ventilation (VE) and lastly to ensure isocapnic conditions, the end-tidal CO2 (PECO2), were also measured. These parameters were determined: 1) While breathing room air (RA), 2) after 30 min of breathing an inspired oxygen fraction (FiO2) of 30% and again 3) after 30 min of breathing and FiO2 of 100%. Fifteen of the subjects were studied on supine and the other 15 in the seated position. In most of the subjects the baseline (RA) values of P0.1 were found to be higher than those reported for normals at sea level. In every case, independent of body position, the P0.1 decreased (less than 0.01) to normal sea level values after 30 min of breathing O2 30%. Likewise, Vi and mechanical impedance also decreased (p less than 0.01) and no changes in Ti/Ttot were noted at this FiO2. No further changes occurred after breathing 100%. The above results show that: 1) The RC output in normal people at altitude (i.e. without mechanical abnormalities but with chronic hypoxia) is increased as compared to sea level.(ABSTRACT TRUNCATED AT 250 WORDS)

[Unilateral agenesis of the main branch of the pulmonary artery]. / Agenesia unilateral de rama principal de la arteria pulmonar.

We studied ten patients with unilateral absence of main branch of pulmonary artery (UAMBPA). Six patients with absent right pulmonary artery (ARPA) and four with the left pulmonary artery (ALPA). The presence of either atrial septal defect, ventricular septal defect and patent ductus arteriosus alone or combinated were associated with pulmonary hypertension (mean pressure of the pulmonary artery greater than 48 mm Hg). The patients without associated cardiac defects were asymptomatic and with little elevation of the pulmonary arterial pressure (mean pressure of the pulmonary artery less than 26 mmHg).

[Pulmonary arteriovenous fistula and lateral decubitus anoxia]. / Fístula arteriovenosa pulmonar y decúbito-latero-deoxia.

The case of a female patient with Rendu-Osler-Weber disease associated with pulmonary arterio-venous fistula localized at the apical segment of the left inferior pulmonary lobe is described. A decrease in the oxygen arterial saturation (SaO2) at adopting the left lateral decubitus position (left-lateral-decubitodeoxia) was found, as well as an increase in the anatomical venoarterial short-circuit (Qs/Qt) in the same position. The resonsible factors of such changes in SaO2 and Qs/Qt related with the body position are analyzed, and the, exceptional in these patients, finding of alteration of pulmonary mechanics is commented.

[Classical interstitial pneumonitis and mixed cryoglobulinemia in a male with Turner phenotype. Report of a case and review of the literature]. / Neumonitis intersticial clásica y crioglobulinemia mixta en un varón con fenotipo Turner. Reporte de 1 caso y revisión de la literatura.

We report a male patient, chromosomal complement 44 XY with Turner's phenotype, who has multiple skeletal, genitourinary and mild cardiac abnormalities, without hypogonadism. This patient developed a diffuse infiltrative pulmonary disease which result in pulmonary fibrosis, respiratory insufficiency and cardiac failure. He has also mixed cryoglobulinemia (Type III) with antigammaglobulin antibodies. The relationship among these problems and his phenotype is discussed. Apparently there is only a coincidental association.

[Pulmonary arterial hypertension of unknown etiology. Study of the cardiopulmonary function]. / Hipertensión arterial pulmonar de etiología desconocida. Estudio de la función cardiopulmonar.

Thirty two cases of pulmonary arterial hypertension of unknown etiology (PAH-UE) were studied. The diagnosis was established by exclusion after the results of hemodinamics studies. Ninety percent of cases had severe PAH (100 mmHg). The end diastolic right ventricular pressure was elevated in 46% of cases. The total pulmonary vascular resistance was increased in the order of the 1700 dinas. seg. cm-5. The cardiac index was 3.3 1/m2 with a right ventricular work index of 3.96 K gm min. The total lung capacity (TLC) was normal, with a vital capacity (VC) of 78% of the predicted value. The residual volume was increased. The mean value of the maximal midexpiratory flow rate (MMFR) was 78%. The A-a gradient of O2 was 30 mmHg, with a venous mixture expressed as a percentage ratio of the cardiac output (Qva/Qt) of 26%. The mean paO2 mmHg and the anatomical pulmonary artery to vein shunt (Qs/Qt) was 9%, with a DLco normal. The clinical hemodinamic correlation was in good agreement. Our results suggested that PAH-UE "per se" has effect in pulmonary function changing slight lung mechanics, and in a moderate degree lung gas exchange. The hipoxemia results meanly from V/Q imbalance.

[Analysis of empyrical factors for the determination of cardiac output]. / Análisis de los factores empíricos para la determinación del gasto cardíaco.

With a method by which no recirculation was possible the area of a dilution curve was obtained. On this basis it was searched what percentage represents the forward triangle of the total surface of the curve. The rôle of the V/F of the sampling system on this portion of the curve was studied, surface from which the empirical constants for the estimation of the cardiac output derivates. The data obtained suggest that the forward surface triangle was V/F dependent V/F less than 1 gave smaller forward triangles, the opposite was true with V/F greater than 1. It was also found that V/F greater than 1 subestimate the total surface of the dye curve, which means cardiac outputs higher than the real. The forward surface of the curve was reduced to a minimal percentage of the total curve when a V/F less than 1 was used. Situation that makes this area non useful to obtain from them empirical factors. If an empirical factor is use in order to measure cardiac output it had to be accepted that an important grade of error is introduced.

[Pulmonary thromboembolism. Occlusion of the right branch of the pulmonary artery caused by lung cancer]. / Tromboembolia pulmonar. Oclusión de la rama derecha de la arteria pulmonar por cáncer del pulmón.

A rare case of an oat cell carcinoma is presented. The clinical picture were those of pulmonary thromboembolism and other extrapulmonary symptoms. There were not respiratory symptoms directly related to the lung carcinoma and the chest film remain normal.

[Coexistence of aorto-pulmonary calcification]. / Calcificación aorto-pulmonar coexistente.

The importance of finding in chest roentgenograms the coexistence of aortic and pulmonary artery calcification in emphasized. This radiologic feature is useful in patients which offered difficulty in the clinical diagnosis, it should suggest as a first possibility in the diagnosis patent ductus arteriosus.