A prospective study on septicemia. II. Clinical manifestations and complications, results of antimicrobial treatment and report of a follow-up study

Role of acute infection in triggering acute coronary syndromes

Acute coronary syndromes are a leading cause of morbidity and mortality worldwide. The mechanisms underlying the triggering of these events are diverse and include increased coronary and systemic inflammatory activity, dominant prothrombotic conditions, increased biomechanical stress on coronary arteries, variations in the coronary arterial tone, disturbed haemodynamic homoeostasis, and altered myocardial metabolic balance. There is experimental evidence that acute infections can promote the development of acute coronary syndromes, and clinical data strongly support a role for acute infections in triggering these events. In our Review, we summarise the pathogenesis of coronary artery disease and present the evidence linking acute infections with the development of acute coronary syndromes. Greater awareness of this association is likely to encourage research into ways of protecting patients who are at high risk.

[Analysis of prognostic factors for mortality in bacteremia and fungemia at a university hospital. Experience of 10 years]

OBJECTIVE

The objective of this study was to determine the prognostic factors in relationship to evolution to death of bacteremia-fungemia (BF) episodes occurred in 1986 and to compare them with the results obtained ten years later in 1996.

PATIENTS AND METHODS

Prospective study of all BF episodes observed at Hospital Universitario La Princesa, Madrid, during the 1985-1986 and 1996-1997 periods. The same definitions were used for the two study periods. The univariate analysis of results was performed with the chi square test and variables with statistical significance with p < 0.10 in the multivariate analysis with the logistic regression model.

RESULTS

A total of 984 episodes were analyzed. There was an increased incidence per 1,000 admissions from 23.58 to 28.44. A change in the relationship of nosocomial acquisition (55.5%-42.6%) to community-acquired episodes (44.1%-57.4%) and an increase in gram-positive organisms (39%-48.6%) compared with gram-negative organisms (53.4%-41.8%) was observed. The organisms recovered most frequently in both periods were Escherichia coli and coagulase-negative Staphylococcus. An overall decrease of mortality rate from 26.2% down to 15.9% (OR: 4.52) was noted. Independent factors with poor prognosis in the first period included age over 60 years (OR: 4.52), underlying disease (OR: 2.79; more than one OR: 6.53), respiratory source (OR: 3.86), DIC (OR: 4.79), hypotension (OR: 3.19); as for the second period, the corresponding independent factors included age > 60 years (OR: 6.48), nosocomial acquisition (OR: 2.62), DIC (OR: 18.7), hypotension (OR: 3.07), and inadequate surgical treatment (OR: 7.61).

CONCLUSIONS

In the last ten years the incidence of BF episodes has increased. In contrast, mortality rate has decreased. Factors with poor prognosis, including age > 60, DIC, and hypotension, still persist.

Nosocomial outbreak of ampicillin resistant Enterococcus faecium: risk factors for infection and fatal outcome

A nosocomial outbreak caused by ampicillin resistant Enterococcus faecium (ARE) was detected at a Norwegian university hospital in January 1995. Prior to this outbreak, ARE were not common in this hospital or other hospitals in Norway. During 1995 and 1996, a total of 149 cases with clinical ARE infection were detected prospectively. A case control study was performed by allocating controls matched for gender, age and ward of admission. Altogether, 123 case control pairs with mean age 70.1 years were included. Isolates from 89 (72. 4%) of the cases were identical or related to the defined outbreak strain as determined by pulsed-field gel electrophoresis (PFGE). In 75 of the patients (60.9%), ARE caused urinary tract infection, five (4.1%) had bacteraemia, 33 (26.8%) had wound infection and 10 (8.1%) had other infections. In a logistic regression model for 1:1 matched samples, the following factors were identified as significant risk factors for ARE infection: underlying neurological disease (OR=33.5), prescription of antimicrobial agents for more than 10 days (OR=8. 99), prescription of cephalosporins (OR=4.69), underlying gastrointestinal disease (OR=3.36) and length of hospital stay per day (OR=1.04). The intrahospital death rate for the cases was 18.7% compared with 8.9% for the controls, corresponding to an excess mortality attributable to ARE infection of 9.8%. A history of carbapenem prescription was the only independent factor contributing to death (OR=5.64) when comparing ARE patients dying in hospital to those surviving.

Thrombocytopenia in a surgical ICU

STUDY OBJECTIVES

To assess the incidence of thrombocytopenia in surgical ICU patients, the factors associated with thrombocytopenia, the outcome of thrombocytopenic patients, and the possible mechanisms involved.

DESIGN

Prospective study.

SETTING

An 8-bed surgical ICU in an 885-bed teaching hospital.

PATIENTS

147 consecutive patients admitted to the surgical ICU during a 6-month period.

MAIN OUTCOME MEASURES

Incidence of thrombocytopenia (defined by a platelet count < 100,000/mm3), risk factors for thrombocytopenia, or death in thrombocytopenic patients identified by a stepwise logistic regression analysis, as well as the mechanisms involved.

RESULTS

Thrombocytopenia occurred in 52 patients (35%) with a mortality rate of 38%, compared with a 20% mortality rate in nonthrombocytopenic patients (p = 0.02). Sepsis, episodes of bleeding or transfusions, and an acute physiology and chronic health evaluation (APACHE) II score of > 15 were the independent risk factors identified for thrombocytopenia. The correction of thrombocytopenia was a protective factor reducing the risk of mortality in thrombocytopenic patients. Disseminated intravascular coagulation was found in 40% of thrombocytopenic patients, elevated platelet-associated IgG in 33%, and hemophagocytic histiocytes in 67%. Combinations of two of these mechanisms were demonstrated in one quarter of thrombocytopenic patients.

CONCLUSIONS

Sepsis was the major independent risk factor identified. Thrombocytopenic patients had a higher ICU mortality due to the severity of overall clinical status. Bone marrow examination could be diagnostic when no obvious causes are demonstrated. Thrombocytopenia probably reflects the severity and course of an underlying pathologic condition, as its correction appears to be a good prognostic factor.

Thrombocytopenia in critically ill surgical patients: a case-control study evaluating attributable mortality and transfusion requirements

BACKGROUND: That thrombocytopenia results in increased mortality or transfusion requirements has not been confirmed by previous studies. We performed a case-control study in which 36 patients who developed severe thrombocytopenia of less than 50x109 platelets/l were carefully matched for the severity of underlying disease and other important variables. RESULTS: Seventeen (47%) thrombocytopenic patients died, versus 10 (28%) matched control patients who were not thrombocytopenic.Nine pairs had a discordant outcome, and in eight of these pairs the thrombocytopenic patient died (exact binomial probability 0.037). The estimated attributable mortality was 19.5% (95% confidence interval 3.2-35.8), and the estimated odds ratio was 2.7 (95% confidence interval 1.02-7.10). Thrombocytopenic patients had comparable values for severity of illness scores between day of admission and day of thrombocytopenia, in contrast with control patients who had a statistically significant decrease in severity of illness scores during the same period. Thirty (83%) of the thrombocytopenic patients required transfusion of blood products, versus 21 (58%) control patients (paired chi2 test 4.92, P < 0.04). The estimated attributable transfusion requirement was 25% (95% confidence interval 5.4-44.6), and the estimated odds ratio was 1.52 (95 confidence interval 1.05-2.20). CONCLUSION: The present study suggests that thrombocytopenia of less than 50 x 109 platelets/l may be a marker for more severe illness and increased risk of death, rather than causative, because a true causal relationship is not established. Thrombocytopenia also leads to an excess of blood product consumption.

Efficacy of a sonic toothbrush for plaque removal by caregivers in a special needs population

Oral hygiene and oral health are a major concern for long-term-care facility residents who are unable to care for themselves. In this six-week study, the efficacy of a sonic toothbrush (Sonicare) was compared with traditional manual brushing in a setting where hygiene care was provided by caregivers. Evaluations of plaque levels were made at baseline and at 2, 4, and 6 weeks according to the Silness and Löe index. The sonic brush was found to be significantly superior to the manual brush over the trial period (MANCOVA; p = 0.026). Plaque reduction at 6 weeks was found to be 38% with the sonic brush and 6% with the manual brush. The results indicate that the sonic brush may be an effective way to provide improved oral health to nursing home subjects when oral care is caregiver-provided.

Bacteremia at a Danish university hospital during a twenty-five-year period (1968-1992)

In the 25-year period 1968-92, 3,317 out of 477,420 patients admitted to Frederiksberg Hospital experienced 3,491 episodes of bacteremia. Enterobacteriaceae dominated as causative agents (57%), following by Gram-positive cocci (31%) and anaerobes (7%). Polymicrobial bacteremia was found in 8% of the episodes. The incidence of Enterobacteriaceae bacteremia culminated in the middle (1978-82) of the period (4.7/1,000 admissions) and decreased during the last decade. Gram-positive bacteremia increased throughout the period (from 1.8 to 2.9; p < 0.001), due mainly to increasing incidences of bacteremia caused by non-hemolytic streptococci, Streptococcus pneumoniae and coagulase-negative staphylococci. Bacteroides fragilis accounted for a rising incidence of anaerobic bacteremia (from 0.3 to 0.7; p < 0.05). Clinical data were available for the 2,599 bacteremic episodes in the 20-year period 1968-87. 59% of these were hospital acquired. Of those, 38% were associated with indwelling catheters, mainly bladder catheters (28%) and i.v. lines (7%). The urinary tract dominated as source of bacteremia (46%), followed by the respiratory (11%) and the gastrointestinal tract (9%). Half of the patients had predisposing underlying diseases, most frequently malignancies (20%) and diabetes mellitus (7%). The mortality rate related to bacteremia decreased from 25% to 11% (p < 0.001). More than half (55%) of the fatal cases related to bacteremia occurred within the first 2 days after the first positive blood culture was obtained. Logistic regression analysis defined 7 variables that independently influenced the outcome related to bacteremia: age, source, culture verification of source, shock, body temperature, leukocyte count and empiric antibiotic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombocytopenia in the intensive care unit

STUDY OBJECTIVE

To determine the prevalence of thrombocytopenia in an ICU and assess which factors were associated with thrombocytopenia.

DESIGN

A review of the medical records of patients admitted during 3 separate months during 1 academic year. Patients must have survived at least 12 h in the ICU.

SETTING

A medical ICU at a university hospital.

PATIENTS

General medicine patients admitted to the ICU.

INTERVENTIONS

All medical records were reviewed. During the ICU stay, daily medications, events, and platelet count were noted. All patients were followed up until death or hospital discharge. In 22 patients, including 18 who had thrombocytopenia, bone marrow aspirates were performed.

MEASUREMENTS AND RESULTS

One hundred sixty-two admissions were evaluated. Thirty-eight (23 percent) had platelet counts less than 100,000/mm3 at least once, and 17 (10 percent) patients had platelet counts less than 50,000/mm3. Several factors were associated with thrombocytopenia; however, only sepsis, use of antineoplastic chemotherapy, elevated creatinine level, or elevated bilirubin value were independent risk factors for severe thrombocytopenia. In only one patient were the bone marrow findings different from those expected by the clinical presentation. Thrombocytopenia was associated with longer hospital stay (p < 0.001) and higher mortality (p < 0.001).

CONCLUSION

Thrombocytopenia is a common occurrence in the ICU, usually due to the underlying disease, and is associated with an increased mortality.

Survey of Escherichia coli septicemia over a six-year period

Escherichia coli was the most frequent species isolated from blood cultures in the Hospital Covadonga of Oviedo (Spain) over a six-year period (474 episodes, 15.3% of the total septicemias and 2.7 episodes per 1,000 patients). Escherichia coli strains were susceptible in greater than 95% of episodes to cefoxitin, cefotaxime, gentamicin, tobramycin and amikacin. In a series of 72 episodes, microbiological features and host factors were studied. No endemic stains were found. Type 1 fimbria was detected in 73.6% of strains and P-fimbriae in 12.5%, without correlation between P-fimbria and urinary infection; 84.7% of the strains were resistant to decomplement human serum; 61.1% produced aerobactin and 20.8% were hemolytic. Factors such as age, hospital location, metastatic focus and surgical treatment were significantly correlated with morbidity and mortality. The global mortality rate was 18%, and in 8.3% of cases was directly associated with septicemia.

Central nervous system complications in patients with bacteremia

The occurrence of central nervous system (CNS) complications was studied retrospectively in 150 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, beta-hemolytic streptococci or Escherichia coli. The incidence and clinical manifestations of different CNS complications were noted during 1 month after the bacteremia. Special attention was paid to vascular complications (infarction or hemorrhage), infections (meningitis or brain abscess) and mental changes when they were the only signs of CNS origin (lowered level of consciousness, confusion or delirium). The risk of cerebral infarction was elevated in the patients with bacteremia during the first month after the positive blood culture as compared with the overall risk of stroke in the general population. 10/150 patients (7%) developed cerebral infarction during that month. Two of these cases were associated with bacterial meningitis and 1 with endocarditis. Mental changes as a main symptom of CNS origin occurred in 27% of patients with bacteremia. Increasing patient age predisposed to this complication. Mental changes were not associated with any bacterial species studied. Altogether 40% of the patients developed CNS complications, which were a significant risk factor for death during the first month after the bacteremia.

Comparative analysis of two blood culture systems (Isolator and a 12-tube system) by cumulative differences in detection power at different times during incubation

A lysis-centrifugation blood culture system (Isolator) and a conventional system (4 tubes of nutrient broth, 4 tubes of semisolid agar, and 4 tubes of thioglycollate agar) were compared after different lengths of incubation by cumulative scoring of differences in detection power. After the first half day of incubation, the Isolator system was already significantly faster in detecting isolates of clinical significance (15 vs. 4, P = 0.02). Maximum difference in first or only detection system was seen after two days of incubation and was based on an overall superior detection of Staphylococcus aureus (11 vs. 0, P = 0.001), and an earlier detection of Enterobacteriaceae (30 vs. 13, P = 0.01) in the Isolator system. On the contrary, the detection of Streptococcus pneumoniae was significantly inferior in the Isolator system (0 vs. 10, P = 0.002). The earlier finding of clinically significant microorganisms in the Isolator system certainly contributes to good patient-care. A drawback of the Isolator system was the finding of clinically insignificant coagulase-negative staphylococci in 11%, compared with 1% in the conventional system. This led to a considerable waste of time and materials in the laboratory. The comparison of the two blood culture systems, based on statistical analysis of cumulative differences in detection power, expressed as the earliest or only findings, gives the optimal information, and is in our opinion the clinically most relevant comparison.

Bacteremia and candidemia in hematological malignancies: clinical findings

171 episodes of bacteremia and candidemia in 142 patients were recorded during the period 1981-1985 in patients with hematological malignancies. Overall mortality, within 1 week of onset of bacteremia, was 20%. Increased mortality was found in patients with poor disease-prognosis (39%), with granulocytopenia for more than 6 days (30%), and in those developing hypotension (49%). Compared to a similar previous study from 1970-1974, the incidence of bacteremia remained unchanged, but the mortality had decreased by 50%. This result could not be explained by changes in microbial spectrum, in patient groups, or in the initial antibiotic regimen used. An improved general condition of these patients due to better supportive treatment may be the single most important factor in improving the outcome of septicemia.