Current controversies in the detection of septicemia

Adverse drug reaction monitoring during antimicrobial therapy for septicemia patients at a university hospital in New Delhi

BACKGROUND/AIMS

Adverse drug reaction (ADR) is an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product. The present study was conducted in order to monitor the frequency and severity of ADR during antimicrobial therapy of septicemia.

METHODS

A prospective, observational, and noncomparative study was conducted over a period of 6 months on patients of septicemia admitted at a university hospital. Naranjo algorithm scale was used for causality assessment. Severity assessment was done by Hartwig severity scale.

RESULTS

ADRs in selected hospitalized patients of septicemia was found to be in 26.5% of the study population. During the study period, 12 ADRs were confirmed occurring in 9, out of 34 admitted patients. Pediatric patients experienced maximum ADRs, 44.4%. Females experienced a significantly higher incidence of ADRs, 66.7%. According to Naranjo's probability scale, 8.3% of ADRs were found to be definite, 58.3% as probable, and 33.3% as possible. A higher proportion of these ADRs, 66.7% were preventable in nature. Severity assessment showed that more than half of ADRs were moderate. Teicoplanin was found to be the commonest antimicrobial agent associated with ADRs, followed by gemifloxacin and ofloxacin.

CONCLUSION

The incidence and severity of ADRs observed in the present study was substantially high indicating the need of extra vigilant during the antimicrobial therapy of septicemia.

Continuous hemoadsorption with a cytokine adsorber during sepsis - a review of the literature

Sepsis is a well-recognized healthcare issue worldwide, ultimately resulting in significant mortality, morbidity and resource utilization during and after critical illness. In its most severe form, sepsis causes multi-organ dysfunction that produces a state of critical illness characterized by severe immune dysfunction and catabolism. Sepsis induces the activation of complement factor via 3 pathways and the release of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-1beta (IL-1β), resulting in a systemic inflammatory response. The inflammatory cytokines and nitric oxide release induced by sepsis decrease systemic vascular resistance, resulting in profound hypotension. The combination of hypotension and microvascular occlusion results in tissue ischemia and ultimately leads to multiple organ failure. Several clinical and experimental studies have reported that treatment using adsorption of cytokines is beneficial during endotoxemia and sepsis. This review article analyzes the efficacy of CytoSorb® adsorber in reducing the inflammatory response during sepsis. The CytoSorb® adsorber is known to have excellent adsorption rates for inflammatory cytokines such as IL-1β, IL-6, IL-8, IL-10, and TNF-α. Studies have demonstrated that treatment with cytokine adsorbing columns has beneficial effects on the survival rate and inflammatory responses in animal septic models. Additionally, several cases have been reported in which treatment with cytokine adsorbing columns is very effective in hemodynamic stabilization and in preventing organ failure in critically ill patients. Although further investigations and clinical trials are needed, treatment with cytokine adsorbing columns may play an important role in the treatment of sepsis in the near future.

Toward an operative diagnosis in sepsis: a latent class approach

BACKGROUND

Recent data have suggested that 18 million of new sepsis cases occur each year worldwide, with a mortality rate of almost 30%. There is not consensus on the clinical definition of sepsis and, because of lack of training or simply unawareness, clinicians often miss or delay this diagnosis. This is especially worrying; since there is strong evidence supporting that early treatment is associated with greater clinical success. There are some difficulties for sepsis diagnosis such as the lack of an appropriate gold standard to identify this clinical condition. This situation has hampered the assessment of the accuracy of clinical signs and biomarkers to diagnose sepsis.

METHODS/DESIGN

Cross-sectional study to determine the operative characteristics of three biological markers of inflammation and coagulation (D-dimer, C-reactive protein and Procalcitonin) as diagnostic tests for sepsis, in patients admitted to hospital care with a presumptive infection as main diagnosis.

DISCUSSION

There are alternative techniques that have been used to assess the accuracy of tests without gold standards, and they have been widely used in clinical disciplines such as psychiatry, even though they have not been tested in sepsis diagnosis. Considering the main importance of diagnosis as early as possible, we propose a latent class analysis to evaluate the accuracy of three biomarkers to diagnose sepsis.

Evaluation of Bactec high blood volume resin media

BACTEC PLUS high-blood-volume resin media (aerobic BP 26 vial and anaerobic BP 27 vial) were compared with standard BACTEC media (aerobic NR 6A and anaerobic NR 7A vial). A total of 2253 blood culture sets, each consisting of the four vials, were collected. Positive cultures were obtained from 403 sets and grew 428 organisms; 271 organisms were considered as significant. The BACTEC PLUS high blood volume resin (BP-HBV) media grew significantly more Staphylococcus aureus, coagulase-negative staphylococci, Candida albicans, Enterococcus faecalis, and Pseudomonas aeruginosa. After taking into account the difference of blood volume between the two systems, only S. aureus was significantly more detected by the aerobic BP 26 vial. An enhanced recovery rate with the anaerobic BP 27 vial could not be established. BP-HBV media had an enhanced recovery rate over the standard BACTEC media for S. aureus and C. albicans in patients receiving antibiotics.

Critical assessment of blood culture techniques: analysis of recovery of obligate and facultative anaerobes, strict aerobic bacteria, and fungi in aerobic and anaerobic blood culture bottles

Recent reports have documented a decrease in anaerobic bacteremias and have questioned the need for routine anaerobic blood cultures. At the same time, we and others have noted an increase in fungal bloodstream infections. In this two-part study, we first compared recoveries of obligate anaerobic bacteria with those of fungi over a 13-year period and then examined the recoveries of all bacteria and fungi in aerobic and anaerobic blood culture bottles during a 12-month period. During the 13-year period, the number of patients with anaerobic bacteremia remained relatively constant (average, 39 patients per year), while the incidence of fungemia steadily increased, from 12 patients in 1978 to 117 patients in 1990. Of the 1,090 anaerobic isolates, 55.1 and 90.2% were recovered in aerobic and anaerobic bottles, respectively, compared with 98.6 and 37.0% of the 2,582 fungi. During the 12-month period of evaluation, 2,980 bacteria and fungi were recovered in cultures collected from 1,555 patients. Overall, 21.1% more organisms were recovered in aerobic bottles than in anaerobic bottles, including significantly more Staphylococcus species; gram-positive aerobic bacilli; Escherichia, Enterobacter, Pseudomonas, Xanthomonas, and Acinetobacter species; miscellaneous gram-negative bacilli; and yeasts. Only anaerobic gram-negative bacilli and non-spore-forming gram-positive bacilli were isolated more commonly in anaerobic bottles. These data support the concepts that bacteremia caused by obligate anaerobic bacteria is decreasing relative to sepsis caused by other bacteria and fungi and that the routine use of unvented anaerobic blood culture bottles reduces the recovery of common aerobic bloodstream pathogens.

Giant cell arteritis

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Blood culture techniques for the diagnosis of melioidosis

The effects of variations in laboratory technique on the speed and sensitivity of isolation of Pseudomonas pseudomallei from blood were evaluated prospectively. Pseudomonas pseudomallei was isolated from 154 of 546 cultures from 325 patients with suspected or confirmed melioidosis. Subcultures after 12 to 24 and 36 to 48 hours of incubation were positive in 52.3% and 80.8% respectively. The yields from 20 ml (blood to broth ratio 1:4) and 50 ml (blood to broth ratio 1:10) brain heart infusion broth bottles were equivalent in patients not receiving treatment for melioidosis. During therapy, the 50 ml bottles grew Pseudomonas pseudomallei significantly faster than the 20 ml bottles (p less than 0.01), and gave a higher overall yield for cultures processed in antimicrobial removal devices (p less than 0.05). These devices themselves increased the speed of isolation of the organism from treated patients (p less than 0.01). In most cases, all bottles collected from a patient before treatment were positive, and a single 20 ml bottle had an estimated relative sensitivity of 85.7% (95% confidence interval 77.1-94.3%). Early subculture should be employed routinely for the laboratory diagnosis of septicaemic melioidosis. However, blood culture techniques do not need to be sophisticated. Culture of 5 ml blood in 20 ml broth is a simple and sensitive procedure suitable for regions where melioidosis is currently under-diagnosed.

Clinical implications of positive blood cultures

Positive blood cultures can be classified according to their veracity (true-positive or false-positive culture), clinical severity (inconsequential or life threatening), place of origin (community acquired or nosocomial), source (primary or secondary), duration (transient, intermittent, or continuous), pattern of occurrence (single episode, persistent, or recurrent), or intensity (high or low grade). In general, however, positive blood cultures identify a patient population at high risk of death. In my studies, patients with positive blood cultures were 12 times more likely to die during hospitalization than patients without positive blood cultures. Many bacteremias and fungemias occur in complicated clinical settings, and it appears that only about one-half of the deaths among affected patients are due directly to infection. Hence, it is appropriate to speak of "crude mortality" and "attributable mortality." Among hospitalized patients, recent trends include rising incidences of Staphylococcus aureus and coagulase-negative staphylococcal and enterococcal bacteremias and a dramatic increase in the incidence of fungemias. The diagnostic and therapeutic implications of blood cultures positive for specific microorganisms continue to evolve and are the subject of a large and growing medical literature.