Optimizing cerebral perfusion pressure during fiberoptic bronchoscopy in severe head injury: effect of hyperventilation.

The aim of this study was to evaluate if Hyperventilation (HV) could avoid the Intracranial Pressure (ICP) peak that occurs during Fiberoptic Bronchoscopy (FB) in severely head injured patients. A Cerebral Perfusion Pressure (CPP) > 75 mmHg was maintained in 34 patients, with a subgroup randomized to receive controlled HV during FB. Measurements were done before the procedure, during maximum ICP values and 30 minutes after FB. The HV group had minor ICP values after FB, without differences in CPP and ICP peak values.

Eficacia de la optimización de la presión de perfusión cerebral durante la fibrobroncoscopía en pacientes con traumatismo encefalocraneano grave / Effectiveness of the cerebral perfusion pressure optimization during fiberoptic bronchoscopy

Objetivo: Evaluar la utilidad de la optimización de la PPC antes, durante y después de la realización de FB, analizando las diferentes variables hemodinámicas cerebrales. Material y método: Estudio prospectivo, del 01/07/96 al 31/07/97. Ingresaron todos los pacientes con TEC con Glasgow ó 8 a los que se les relizó FB tanto para lavado broncoalveolar (BAL) como para resolución de atelectasias. Todos los pacientes se encotraban intubados, sedados y relajados, con asistencia respiratoria mecánica (ARM) y monitorizados con: catéter de fibra óptica para la medición de Presión Intracraneana (PIC), oximetría cerebral (rSO2) y de pulso (SaO2), capnografía (ETCO2) y catéteres arterial y venoso central. Se calculó: PPC (TAM-PIC), contenido arterial y venoso de O2, diferencia arterio-venosa de O2 cerebral (Dav02C), índice de extracción de O2 cerebral (SaO2-rSO2), consumo metabólico de O2 cerebral (CMO2C) (PCO2xDavO2C). Previo a la FB se mantuvo una PPC = 70 mmHg, una SaO2 = 95 por ciento, una ETCO2 ó 35mmHg y una rSO2 > 55 por ciento. Todas las variables se midieron y calcularon antes de comenzar la FB, luego de la optimización, en el momento de mayor PIC y 30 minutos después de la FB. El análisis estadístico se realizó con el test de Student y el test de correlación de Pearson. Valores de p ó 0,05 o de r2 >0,5, fueron considerados significativos...

Eficacia de la optimización de la presión de perfusión cerebral durante la fibrobroncoscopía en pacientes con traumatismo encefalocraneano grave / Effectiveness of the cerebral perfusion pressure optimization during fiberoptic bronchoscopy

Objetivo: Evaluar la utilidad de la optimización de la PPC antes, durante y después de la realización de FB, analizando las diferentes variables hemodinámicas cerebrales. Material y método: Estudio prospectivo, del 01/07/96 al 31/07/97. Ingresaron todos los pacientes con TEC con Glasgow ó 8 a los que se les relizó FB tanto para lavado broncoalveolar (BAL) como para resolución de atelectasias. Todos los pacientes se encotraban intubados, sedados y relajados, con asistencia respiratoria mecánica (ARM) y monitorizados con: catéter de fibra óptica para la medición de Presión Intracraneana (PIC), oximetría cerebral (rSO2) y de pulso (SaO2), capnografía (ETCO2) y catéteres arterial y venoso central. Se calculó: PPC (TAM-PIC), contenido arterial y venoso de O2, diferencia arterio-venosa de O2 cerebral (Dav02C), índice de extracción de O2 cerebral (SaO2-rSO2), consumo metabólico de O2 cerebral (CMO2C) (PCO2xDavO2C). Previo a la FB se mantuvo una PPC = 70 mmHg, una SaO2 = 95 por ciento, una ETCO2 ó 35mmHg y una rSO2 > 55 por ciento. Todas las variables se midieron y calcularon antes de comenzar la FB, luego de la optimización, en el momento de mayor PIC y 30 minutos después de la FB. El análisis estadístico se realizó con el test de Student y el test de correlación de Pearson. Valores de p ó 0,05 o de r2 >0,5, fueron considerados significativos...(AU)

HIV-specific immunity following immunization with HIV synthetic envelope peptides in asymptomatic HIV-infected patients.

OBJECTIVE: A phase I trial was conducted to evaluate the safety and immunogenicity of an HIV synthetic peptide vaccine in HIV-seropositive individuals. The immunogens used in this study were PCLUS 3-18MN and PCLUS 6.1-18MN envelope peptides. METHODS: Eight HIV-infected patients received six subcutaneous injections of 160 microg PCLUS 3-18MN in Montanide ISA 51 and were followed longitudinally for a year after the first immunization. Peripheral blood mononuclear cells (PBMC) were tested for peptide-specific T helper and cytotoxic T cell (CTL) responses, HIV-1MN neutralizing antibodies and antibodies against HIV PCLUS 3 and P18 MN peptides. RESULTS: PCLUS 3-1 8MN-specific T helper responses were significantly increased at 36 weeks (P < 0.05, after adjustment for multiple comparisons) following initial immunization with PCLUS 3-18MN. A P18MN-specific CTL response, not present prior to vaccination, was observed after immunization in one patient. Serum HIV-1 MN-neutralizing antibody titers increased in each of the three patients who had low titers prior to immunization. Plasma HIV RNA levels and CD4 cell counts did not change appreciably during the study period. CONCLUSIONS: This trial demonstrates that both peptides can be safely administered to HIV-infected individuals and that PCLUS 3-18MN induces increases in HIV peptide-specific immune responses.

[Normograms of spirometric values for the city of Buenos Aires]. / Valores espirométricos normales para la ciudad de Buenos Aires.

There is a large variability between the different normograms of spirometric values, so that we designed our normogram for Buenos Aires and Gran Buenos Aires. We performed forced spirometry, under American Thoracic Society standardization, in 237 normal subjects (105 females) between 18 to 86 years old, and 144 to 194 cm. We measured Forced Vital Capacity (FVC), forced Expiratory Volume in one second (FEV1), and forced expiratory flow during the middle half of the Forced vital capacity (FEF25-75), in previously calibrated by the explosive decompressor spirometers. Linear regression using height and age was used for each measured value for each sex. The values obtained were in normal distribution, so that we determined the Low Limit of Normality calculating the 95% confidence interval to one tail, and this should replace the common method of the fixed percent of each value to determine the lower limit of normality for a predicted value.

Relationship between supramaximal flows and flow-limiting mechanisms.

The aim of this study was to evaluate the relationship between supramaximal flows (SF) and indices of airway mechanics. We studied 26 asymptomatic young subjects (13 smokers, mean +/- SD 15.9 +/- 6.6 pack-years. Subjects performed maximal expiratory flow-volume (MEFV) curves, according to the American Thoracic Society (ATS) criteria, on a rolling-seal spirometer and then repeated them through a specially devised valve, which occluded the mouthpiece either 3 or 6 times.s-1 with a ratio of open:closed time of 3:1. Envelope MEFV curves for 3 and 6 Hz occlusions were constructed passing through the SF obtained after each occlusion, and the increment in flow at 50% of vital capacity was measured with respect to the basal curve (delta V' max50). We found that the delta V' max50 at 3 and 6 Hz correlated to the baseline forced mid-expiratory flow (FEF25-75) in % of predicted value (r = -0.73 and r = -0.55, respectively). our results suggest that inhomogeneities within the lung are an important mechanism in the occurrence of supramaximal flow in normal subjects.