[Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia]. / Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas.

Between February and September 1997, 6588 blood cultures at the Instituto de Cardiología y Cirugía Cardiovascular and Hospital de Niños Ricardo Gutiérrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3%) were monomicrobial episodes and 14 (4.7%) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10% CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7% to 4.7%. Taking into account the total number of bacteremias, only in 3 out of 294 (1%), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas / Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia

Between February and September 1997, 6588 blood cultures at the Instituto de CardiologÝa y CirugÝa Cardiovascular and Hospital de Niños Ricardo GutiÚrrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3) were monomicrobial episodes and 14 (4.7) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10 CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7 to 4.7. Taking into account the total number of bacteremias, only in 3 out of 294 (1), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas / Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia

Between February and September 1997, 6588 blood cultures at the Instituto de CardiologYa y CirugYa Cardiovascular and Hospital de Niños Ricardo GutiUrrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3) were monomicrobial episodes and 14 (4.7) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10 CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7 to 4.7. Taking into account the total number of bacteremias, only in 3 out of 294 (1), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.(AU)

Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas. / [Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia]

Between February and September 1997, 6588 blood cultures at the Instituto de Cardiología y Cirugía Cardiovascular and Hospital de Niños Ricardo Gutiérrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3

) were monomicrobial episodes and 14 (4.7

) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10

CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7

to 4.7

. Taking into account the total number of bacteremias, only in 3 out of 294 (1

), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

[The role of the venous reservoir in maintaining arterial pressure during hemodialysis. Effect of dihydroergotamine]. / Rôle du réservoir veineux dans le maintien de la pression artérielle au cours de l'hémodialyse. Action de la dihydroergotamine.

Hemodialysis has been reported to produce a decrease in cardiac output partially related to a peripheral relocation of blood volume. In order to further evaluate this hypothesis, the hemodynamic effects of dihydroergotamine (DHE), a veino-constrictor drug, were investigated in 5 patients undergoing hemodialysis. Body weight, total blood volume, arterial blood pressure, cardiac output and heart rate were obtained before (period A) and immediately after hemodialysis: before (period B) and after an acute infusion of DHE (period C); studies were performed in supine then in tilted position. During period B, cardiac index decreased by 27% (p less than 0.05) and stroke index by 35% (p less than 0.02). Acute infusion of DHE produced a significant increase in cardiac index (+ 18%, p less than 0.05), stroke index (+ 28%, p less than 0.05) and blood pressure (+ 20%, p less than 0.05). These results indicate that the hemodynamic alterations induced by hemodialysis may be partially reversed by contraction of the capacitance system following DHE infusion.