Continuous-monitoring blood culture screening system improves the detection of bacteremia in neutropenic patients

One reason for the underdiagnosis of bacteremia as an etiology of fever in neutropenic patients might lie in inefficient blood culture techniques. This possibility was investigated in a retrospective study by comparing the efficacies of a manual and an automated blood culture system used to detect bacteremia in such patients. All neutropenic fever episodes accompanying all 93 intensive chemotherapy cycles of 26 consecutive patients with acute myelogenous leukemia (AML) enrolled in Finnish Leukemia Group AML 86 trial and treated in Oulu University Hospital over 3 1/2 years were analyzed. The chemotherapy protocol and the supportive care of the patients remained the same during the whole period. In 1990-91 the blood cultures were made manually and in 1992-93 with an automated continuous-monitoring culture screening system. Evaluable febrile episodes numbered 53 during 1990-91 and 73 during 1992-93. There was a statistically significant increase (p < 0.05) of culture-positive episodes, from 21% to 40%, when the continuous-monitoring system was adopted. The new method proved to be better than the manual one in detecting bacteremia of neutropenic patients.

Effects of anti-neoplastic agents on the recovery of bacteria and yeasts in an automated blood culture system

The effects of 7 anti-neoplastic agents on the recovery of 5 aerobic gram-positive cocci, gram-negative rods and yeasts were studied in 2 different automated blood culture systems using an experimental model. In the absence of anti-neoplastic agents, the growth of gram-positive cocci was detected significantly earlier in standard than in FAN aerobic bottles. In the presence of 100 microM doxorubicin, however, the growth of gram-positive cocci was totally inhibited in standard culture conditions, while in FAN bottles the agent has no inhibitory effect. Etoposide at a concentration of 100 micromol/l also significantly delayed the growth of cocci in standard conditions. Neither the culture bottles nor the anti-neoplastic agents tested had any effect on the growth of gram-negative rods and yeasts. The results suggest that the anti-neoplastic agents present in blood might disturb the growth of gram-positive cocci in blood culture. This should be considered when validating blood culture systems and evaluating blood cultures of chemotherapy-receiving febrile patients.

Night-rest urinary catecholamine excretion in relation to aspects of free time, work and background data in a teacher group

Free time, work and background data were related to night-rest catecholamine excretion rates in a teacher group (n = 137) during an autumn term. The explained interindividual variance increased slightly towards the end of the term. Adrenaline excretion was predicted better than noradrenaline, notedly by coffee consumption, amount of physical activity, and subjective stress feelings which explained 16% of the variance in adrenaline excretion during night rest. However, the results indicated that the differences in catecholamine excretion during night rest remained mostly unpredictable.