Role of routine blood cultures in detecting unapparent infections during continuous renal replacement therapy

OBJECTIVE

Continuous renal replacement therapy (CRRT) is frequently employed in the management of renal failure in unstable intensive care patients. At some centers, blood cultures are performed routinely while on CRRT to monitor for occult bacteremia. We questioned the role of routine blood cultures (RBC) in diagnosing underlying infections in these often afebrile patients.

DESIGN

Retrospective cohort study (1998-2003).

SETTING

Medical, surgical and pediatric intensive care units in a tertiary care teaching hospital. METHODS/MEASUREMENTS: We undertook a retrospective chart review of all 101 episodes of CRRT performed in our hospital since 1998. The primary endpoint of the study was the number of positive cultures that changed patient management. For each positive result, documented infection and parameters of sepsis were noted.

RESULTS

There were 101 treatments of CRRT in 98 patients. A total of 698 routine RBC bottles were drawn, a mean of 7.2+/-7 per patient; of those, 29 (4%) were positive in 17patients, documenting 11 bacteremias. Six positive cultures represented contaminants. In all but one case, infection was known or signs of sepsis were present prior to receipt of the culture result.

CONCLUSIONS

For patients on CRRT, RBC are rarely positive, and do not detect occult infection in the absence of clinical evidence of infection for the majority of patients. Because routine cultures utilize significant resources, and can result in false-positive results, RBC should not be performed in these patients. Careful clinical monitoring, with blood cultures performed at the first clinical suggestion of an infection, should detect all clinically relevant infections.

Operationalizing a comprehensive neurobehavioral plan

The formulation and implementation of a workable and effective plan of care for the complex rehabilitation patient are nursing challenges. Even more challenging, however, is putting the plan into operation over a 24-hour period. Staffing variations, patients' circadian rhythms, and visiting hours are only a few of the factors that require consideration when formulating a viable plan of care. The purpose of this article is to discuss strategies that have been effective in providing consistent, safe, therapeutic care for the patient population on a 39-bed neurobehavioral unit that treats mostly individuals with traumatic brain injuries.

Identity of V factor in culture medium used for prior growth of two strains of Staphylococcus aureus

Staphylococcus aureus ATCC 12598 and ATCC 25923 were starved of pyridine nucleotides and precursors and then grown in a semidefined medium containing [carbonyl-14C]nicotinamide. Samples of medium from late-exponential-phase and stationary-phase cultures were analyzed for 14C-metabolites. In all cases, V factor was present primarily as NAD.