Bedside prediction of mortality from bacteremic sepsis. A dynamic analysis of ICU patients

Predictive 5-year survivorship model of cystic fibrosis

The objective of this study was to create a 5-year survivorship model to identify key clinical features of cystic fibrosis. Such a model could help researchers and clinicians to evaluate therapies, improve the design of prospective studies, monitor practice patterns, counsel individual patients, and determine the best candidates for lung transplantation. The authors used information from the Cystic Fibrosis Foundation Patient Registry (CFFPR), which has collected longitudinal data on approximately 90% of cystic fibrosis patients diagnosed in the United States since 1986. They developed multivariate logistic regression models by using data on 5,820 patients randomly selected from 11,630 in the CFFPR in 1993. Models were tested for goodness of fit and were validated for the remaining 5,810 patients for 1993. The validated 5-year survivorship model included age, forced expiratory volume in 1 second as a percentage of predicted normal, gender, weight-for-age z score, pancreatic sufficiency, diabetes mellitus, Staphylococcus aureus infection, Burkerholderia cepacia infection, and annual number of acute pulmonary exacerbations. The model provides insights into the complex nature of cystic fibrosis and supplies a rigorous tool for clinical practice and research.

Soluble L-selectin at levels present in septic patients diminishes leukocyte-endothelial cell interactions in mice in vivo: a mechanism for decreased leukocyte delivery to remote sites in sepsis

OBJECTIVE

Recent in vivo studies of both septic humans and animals demonstrate that leukocyte delivery is attenuated to sites remote from the primary infection. The mechanisms for this are not entirely clear. L-selectin is integral to rolling, the first step in leukocyte recruitment to an inflammatory site. L-selectin is shed from leukocytes in sepsis, resulting in increased levels of soluble L-selectin in plasma (2.33 microg/mL). This study investigates the effects of soluble L-selectin at levels found in sepsis on leukocyte trafficking in vivo.

DESIGN

Prospective, controlled trial.

SETTING

Surgical research laboratory in a university hospital.

SUBJECTS

Swiss white male mice of 25-35 g.

INTERVENTIONS

Mice were randomized to one of three study groups: soluble L-selectin 2.33, soluble L-selectin 8.0, or albumin. Intravital microscopy was performed on postcapillary venules of 20-40 microm in diameter in the cremaster muscle of mice. Leukocyte-endothelial cell interactions (rolling, adherence, and rolling velocity) were measured pre- and post- (1, 15, 30, and 45 mins) intravenous infusion of human recombinant soluble L-selectin (2.33 and 8.0 microg/mL) or human albumin (8.0 microg/mL).

MEASUREMENTS AND MAIN RESULTS

The intravenous administration of soluble L-selectin to a systemic concentration of 2.33 microg/mL diminished rolling significantly. Soluble L-selectin at 8.0 microg/mL decreased rolling and increased rolling velocity to a greater degree. Injection of albumin did not alter leukocyte-endothelial cell interactions at any time point. No difference between groups in blood pressure, shear rate, or leukocyte counts was detected.

CONCLUSIONS

Soluble L-selectin diminishes leukocyte rolling at levels present in sepsis (2.33 microg/mL). This effect is dose dependent, and could not be explained by differences in blood pressure, shear rate, or leukocyte counts. These findings identify increased soluble L-selectin levels as one of the mechanisms for decreased leukocyte delivery and exudation to remote sites in septic patients.

Prediction of shock in febrile medical patients with a clinical infection

OBJECTIVE

Shock in the course of fever is likely caused by septic shock. Because septic shock carries a high mortality rate, early recognition could benefit the patient. We tried to predict the development of shock in medical patients with fever and a clinical infection, on the basis of clinical and microbiological information, and to evaluate the role therein of systemic inflammatory response syndrome (SIRS) criteria: abnormal body temperature, tachycardia, tachypnea, and abnormal white blood cell counts.

DESIGN

Prospective observational study.

SETTING

Department of Internal Medicine at a university hospital.

PATIENTS

Patients were 212 consecutive medical patients with newly onset fever (temperature, >38.0 degrees C axillary or >38.3 degrees C rectally) and a clinical source of infection.

MEASUREMENTS AND MAIN RESULTS

Of the 212 patients enrolled, 14 developed shock (i.e., a decrease in systolic arterial blood pressure of >40 mm Hg) during a maximum follow-up period of 7 days after inclusion. In univariate analyses, advanced age, prior urogenital disease, an abdominal source, nosocomial infections, and bacteremia predisposed patients to shock (p < .05). For clinical variables, obtained daily for 2 days after inclusion, a low performance (p < .001), the peak respiratory rate (p < .05), the peak heart rate (p < .05), the nadir score on the Glasgow Coma Scale (p < .005), the peak and nadir white blood cell counts (p < .005), and the nadir albumin (p < .01) and peak creatinine concentrations in blood (p < .001) predicted shock development. In multivariate analysis, the presence of bacteremia, the peak respiratory rate, the nadir Glasgow Coma Scale score, and the peak white blood cell count positively and the peak erythrocyte sedimentation rate negatively contributed to prediction of shock development. In contrast, SIRS had less predictive value, mainly because of lack of predictive value of peak heart rate and temperature in multivariate models.

CONCLUSION

In febrile medical patients with a clinical infection, the development of shock involves an interaction between circulating microbial products and the host response, which can be recognized clinically by variables easily obtained at the bedside and partly different from the set used to define SIRS.

The clinical features of severe community-acquired pneumonia presenting as septic shock. Norasept II Study Investigators

PURPOSE

The purpose of this article was to determine the outcome, clinical and prognostic features, and microbiology of a large group of patients with community-acquired pneumonia (CAP) presenting in septic shock.

MATERIALS AND METHODS

The placebo limb of the Norasept II database was examined. Data were collected on patients in septic shock with a diagnosis of CAP who presented to a participating site from home.

RESULTS

One hundred and forty-eight patients met the study criteria. The 28-day survival was 53%. One hundred and four pathogens were isolated from 77 (52%) patients with 24 (16%) patients having polymicrobial infections. The most common pathogen was Streptococcus pneumoniae (19%), followed by Staphylococcus aureus (18%), Haemophilus influenzae (14%), Klebsiella pneumoniae (11%), and Pseudomonas aeruginosa (7%). Infection with P aeruginosa or Acinetobacter species carried a very high mortality (82%). The only clinical variables recorded in the database that could identify patients with pseudomonas or acinetobacter infection was a history of alcohol abuse. Comorbidities were present in 74% of patients, involving predominantly the cardiorespiratory system. Logistic regression analysis demonstrated APACHE II score and serum interleukin 6 (IL-6) concentration to be significant independent predictors of mortality. Patients with pseudomonas or acinetobacter infection had significantly higher IL-6 levels and significantly lower tumor necrosis factor alpha levels when compared with the rest of the cohort of patients.

CONCLUSION

A diverse spectrum of both gram-positive and gram-negative pathogens were implicated in patients with CAP presenting in septic shock, necessitating broad spectrum empiric antimicrobial coverage. This coverage should include antipseudomonal activity, particularly in alcoholic patients. Severity of illness (APACHE II score) and IL-6 levels were important prognostic factors. Infection with P aeruginosa and Acinetobacter species carried a very high mortality.

Prevalence of infections in intensive care units in Mexico: a multicenter study

OBJECTIVE

To determine the 1-day prevalence of community-acquired, hospital-acquired, or intensive care unit (ICU)-acquired infections in Mexican ICUs. To identify associated risk factors, predominant infecting organisms, and mortality rates.

DESIGN

A 1-day point-prevalence study.

SETTING

A total of 254 adult ICUs in Mexico.

PATIENTS

Adult patients hospitalized in the participating ICUs.

RESULTS

A total of 895 patients were studied, of whom 521 patients (58.2%) were infected. Community-acquired infection occurred in 214 patients (23.9%), non-ICU nosocomial infection occurred in 99 patients (11.1%), and 208 patients had at least one ICU-acquired infection (23.2%; 1.45 episodes/patient). The most frequently reported ICU-acquired infections were pneumonia (39.7%), urinary tract infections (20.5%), wound infection (13.3%), and bacteremia (7.3%). The mortality rate for the ICU-acquired infections after 6 wks of follow-up was 25.5%. Multivariate regression analysis showed the following risk factors for ICU-acquired infections: neurologic failure as a primary cause of admission (odds ratio [OR], 1.697; 95% confidence interval [CI], 1.001-2.839); length of stay in ICU (OR, 1.119; 95% CI, 1.091-1.151); number of therapeutic and/or diagnostic interventions during the preceding week (OR, 1.118; 95% CI, 1.016-1.231); peripherally administered infusion of hyperosmolar solutions (OR, 6.93; 95% CI, 2.452-21.661); sedative usage in the preceding week (OR, 1.751; 95% CI, 1.183-2.602); history of an emergency surgery in the preceding month (OR, 1.875; 95% CI, 1.251-2.813). The administration of antimicrobial treatment if there was an infection decreased the risk of death (OR, 0.406; 95% CI, 0.204-0.755).

CONCLUSIONS

Evidence of a high frequency of nosocomial infections was found, and potential risk factors for acquiring infections and mortality were identified. Mortality rates according to the hierarchy of the systemic inflammatory response syndrome in Latin American ICUs are reported.

Severe sepsis and septic shock. Definitions, epidemiology, and clinical manifestations

Severe sepsis and septic shock are frequently encountered conditions in today's hospital environment. The incidence appears to be increasing despite our growing armamentarium of antibiotics and our enhanced knowledge of the pathophysiologic processes at play. The clinical presentation may take a variety of forms, especially in patients at the extremes of age and in the immunocompromised population. A high index of suspicion and prompt institution of appropriate antimicrobial treatment is mandatory for a successful outcome. It is hoped that adoption of uniform definitions will aid in research and in effective communication concerning sepsis and its adverse sequelae.

A one-year prospective study of nosocomial bacteraemia in ICU and non-ICU patients and its impact on patient outcome

A one-year, prospective, two-observational cohort study was performed to evaluate the incidence and outcome in hospitalized patients (ICU and non-ICU) of nosocomial bacteraemia, and to assess its prognostic value in the ICU group. A group of 18 098 hospitalized patients and a group of 291 consecutive ICU patients were followed. Prognostic factors were determined using single and multivariable analyses. 109 (90 non-ICU and 19 ICU) patients developed 118 nosocomial bacteraemic episodes. The incidence of nosocomial bacteraemia was 6.0 per 1000 admissions (95% confidence interval (CI): 5-7%) and 65 per 1000 admissions in ICU patients (95% CI: 4.5-8.5%). Gram-positive and Gram-negative bacteria were 63/133 (47%) and 70/133 (53%) of the isolated micro-organisms respectively. Crude mortality rates were 41/109 (38%) with adverse outcome associated with mechanical ventilation (OR: 3.6; 95% CI: 1.4-9.2, P =0.01), neutropenia (OR: 7.7; 95% CI: 0.8-73.1;P =0.07) while gastro-intestinal surgery was associated with an improved outcome (OR: 0.4; 95% CI: 0.16-0.96;P =0.04). Of the 291 ICU patients, 19 acquired 22 episodes of nosocomial bacteraemia, and 18 were referred from the wards with documented nosocomial bacteraemia. Of these 37 bacteraemic patients, 17 (46%) died. When adjusting for predictors of death (SAPS II>/=40, cardiac and neurological failure), nosocomial bacteraemia markedly influence the outcome in ICU patients (OR: 3.4; 95% CI: 1.3-8.7;P =0.010). This study suggests that the outcome of nosocomial bacteraemia in hospitalized patients is poor in ventilated and neutropenic patients and that nosocomial bacteraemia per se influenced outcome in ICU patients.

Predicting bacteremia and bacteremic mortality in liver transplant recipients

Predictors of bacteremia and mortality in bacteremic liver transplant recipients were prospectively assessed. One hundred eleven consecutive episodes of fever or infections were documented in 59 patients over a 4-year period. Forty-nine percent (29 of 59 patients) of the patients had bacteremia, 39% (23 of 59 patients) had nonbacteremic infections, and 12% (7 of 59 patients) had fever of noninfectious cause. Primary (catheter-related) bacteremia (31%; 9 of 29 patients), pneumonia (24%; 7 of 29 patients), abdominal and/or biliary infections (14%; 4 of 29 patients), and wound infections (10%; 3 of 29 patients) were the predominant sources of bacteremia. Diabetes mellitus (odds ratio, 6.9; P =.03) and serum albumin level less than 3.0 mg/dL (odds ratio, 0.14; P =.02) were independently significant predictors of bacteremia compared with nonbacteremic infections. Mortality at 14 days was 28% (8 of 29 patients) in those with bacteremia compared with 4% (1 of 23 patients) in those with nonbacteremic infections and 0% (0 of 7) in patients with fever of noninfectious cause (P =.03). Intensive care unit stay at the time of bacteremia (100% v 47%; P =.005), absence of chills (0% v 53%; P =.005), lower temperature at the onset of bacteremia (99.2 degrees F v 101.5 degrees F; P =.009), lower maximum temperature during the course of bacteremia (99.3 degrees F v 102 degrees F, P =.008), greater serum bilirubin level (7.6 v 1.5 mg/dL; P =.024), presence of abnormal blood pressure (80% v 16%; P =. 0013), and greater prothrombin time (15.6 v 13.3 seconds; P =.013) were significantly predictive of greater mortality in the bacteremic patients. These data have implications for discerning the likelihood of bacteremia and initiation of empiric antibiotics pending cultures. Lack of febrile response in bacteremic liver transplant recipients portended a poorer outcome.

Impact of immunomodulating therapy on morbidity in patients with severe sepsis

We assessed the impact, over a 28-d period, of therapy with the tumor necrosis factor (TNF) neutralizing receptor fusion protein (p55-IgG) on the incidence of end-organ failures in patients with severe sepsis or early septic shock in a subgroup of 165 patients recruited into a randomized, multicenter clinical trial to receive placebo (n = 78) or a single infusion of p55-IgG, 0.083 mg/kg (n = 87). At study entry, distribution of organ dysfunctions and other baseline characteristics were similar for the two study groups. Treatment with p55-IgG was associated with a trend toward reduced 28-d mortality (p = 0.07), a decreased incidence of new organ dysfunctions (relative risk [RR], 0.57; 95% confidence interval [95% CI] 0.29 to 1.10, p = 0.10), and a decreased overall incidence-density of organ failures (RR 0.65; 95% CI 0.60 to 0.71, p = 0.0001). Patients treated with p55-IgG had more organ failure-free days after study entry than those who received placebo. Average intensive care unit (ICU) stay was 2.6 d shorter (95% CI 0.2 to 5.0) for patients who received p55-IgG than for those who received placebo. For those patients who survived, this difference was 4.1 d (95% CI 1.6 to 6.6). Duration of ventilatory support was 3.2 d shorter (95% CI 0.1 to 6.3) among 28-d survivors who received p55-IgG, compared with placebo. In conclusion, in the population of septic patients studied, treatment with p55-IgG was associated with a trend toward shorter need for mechanical ventilatory support, a decreased length of stay (LOS), and a decreased incidence and duration of organ failure.

Severity scoring and outcome assessment. Computerized predictive models and scoring systems

Severity of illness scoring systems and standardized death ratios are being used with increasing frequency as markers of quality of care and to compare and contrast the performance of ICUs. However, numerous factors unrelated to the quality of care delivered may impact the severity of illness score and standardized death ratios. This article reviews the commonly used severity scoring systems and factors that affect their predictive performance.

Attributable morbidity and mortality of catheter-related septicemia in critically ill patients: a matched, risk-adjusted, cohort study

OBJECTIVE

To determine the attributable risk of death due to catheter-related septicemia (CRS) in critically ill patients when taking into account severity of illness during the intensive-care unit (ICU) stay but before CRS.

DESIGN

Pairwise-matched (1:2) exposed-unexposed study.

SETTING

10-bed medical-surgical ICU and an 18-bed medical ICU.

PATIENTS

Patients admitted to either ICU between January 1, 1990, and December 31, 1995, were eligible. Exposed patients were defined as patients with CRS; unexposed controls were selected according to matching variables.

METHODS

Matching variables were diagnosis at ICU admission, length of central catheterization before the infection, McCabe Score, Simplified Acute Physiologic Score (SAPS) II at admission, age, and gender. Severity scores (SAPS II, Organ System Failure Score, Organ Dysfunction and Infection Score, and Logistic Organ Dysfunction System) were calculated four times for each patient: the day of ICU admission, the day of CRS onset, and 3 and 7 days before CRS. Matching was successful for 38 exposed patients. Statistical analysis was based on nonparametric tests for epidemiological data and on Cox's models for the exposed-unexposed study, with adjustment on matching variables and prognostic factors of mortality.

RESULTS

CRS complicated 1.17 per 100 ICU admissions during the study period. Twenty (53%) of the CRS cases were associated with septic shock. CRS was associated with a 28% increase in SAPS II. Crude ICU mortality rates from exposed and unexposed patients were 50% and 21%, respectively. CRS remained associated with mortality even when adjusted on other prognostic factors at ICU admission (relative risk [RR], 2.01; 95% confidence interval [CI95], 1.08-3.73; P=.03). However, after adjustment on severity scores calculated between ICU admission and 1 week before CRS, the increased mortality was no longer significant (RR, 1.41; CI95, 0.76-2.61; P=.27).

CONCLUSION

CRS is associated with subsequent morbidity and mortality in the ICU, even when adjusted on severity factors at ICU admission. However, after adjustment on severity factors during the ICU stay and before the event, there was only a trend toward CRS-attributable mortality. The evolution of patient severity should be taken into account when evaluating excess mortality induced by nosocomial events in ICU patients.

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.

Bacteraemia in the adult intensive care unit of a teaching hospital in Nottingham, UK, 1985-1996

Bacteraemia is an important cause of morbidity and mortality in the intensive care unit. In this study the distribution of organisms causing bacteraemic episodes in patients in the adult intensive care unit of a large teaching hospital was determined. Particular emphasis was placed on the type of organisms isolated from community- and hospital-acquired bacteraemia, the suspected source of infection, the possible risk factors associated with bacteraemia, and outcome. The incidence of bacteraemia and fungaemia increased from 17.7 per 1000 admissions in 1985 to 80.3 in 1996. A total of 315 episodes of bacteraemia and fungaemia were documented over a 12-year period, of which 18% were considered community-acquired and 82% hospital-acquired. Gram-positive and gram-negative bacteria accounted for 46.9% and 31.5% of the episodes, respectively. Polymicrobial infection accounted for 17.8% and fungi for 3.8% of the episodes. Staphylococcus aureus (22.5%), Staphylococcus epidermidis (7.6%), and Streptococcus pneumoniae (7.9%) were the predominant gram-positive bacteria implicated, whereas Escherichia coli (6%), Enterobacter cloacae (7%), Klebsiella aerogenes (3.8%), Pseudomonas aeruginosa (5.1%), and Acinetobacter spp. (3.8%) were the predominant gram-negative bacteria isolated. The two most common sources of infection were the respiratory tract (39.7%) and an intravascular line (24.5%), but in 8.9% of episodes the focus of infection remained unknown. Bacteraemic patients stayed in the unit for a longer period (12 days) than did non-bacteraemic patients (3 days). The overall mortality related to bacteraemia and candidaemia was 44.4%. Surveillance of bacteraemia in the intensive care unit is important in detecting major changes in aetiology, e.g., the increasing incidence of gram-positive bacteraemia, the emergence of methicillin-resistant Staphylococcus aureus in 1995, and the emergence of Enterobacter cloacae. It is of value in determining empirical antimicrobial therapy to treat presumed infection pending a microbiological diagnosis and in directing the development of guidelines for infection prevention, e.g., guidelines for central venous catheter care.

Intravenous amiodarone for acute heart rate control in the critically ill patient with atrial tachyarrhythmias

Control of heart rate in critically ill patients who develop atrial fibrillation or atrial flutter can be difficult. Amiodarone may be an alternative agent for heart rate control if conventional measures are ineffective. We retrospectively studied intensive care unit patients (n = 38) who received intravenous amiodarone for heart rate control in the setting of hemodynamically destabilizing atrial tachyarrhythmias resistant to conventional heart rate control measures. Atrial fibrillation was present in 33 patients and atrial flutter in 5 patients. Onset of rapid heart rate (mean 149 +/- 13 beats/min) was associated with a decrease in systolic blood pressure of 20 +/- 5 mm Hg (p <0.05). Intravenous diltiazem (n = 34), esmolol (n = 4), or digoxin (n = 24) had no effect on heart rate, while reducing systolic blood pressure by 6 +/- 4 mm Hg (p <0.05). The infusion of amiodarone (242 +/- 137 mg over 1 hour) was associated with a decrease in heart rate by 37 +/- 8 beats/min and an increase in systolic blood pressure of 24 +/- 6 mm Hg. Both of these changes were significantly improved (p <0.05) from onset of rapid heart rate or during conventional therapy. Beneficial changes were also noted in pulmonary artery occlusive pressure and cardiac output. There were no adverse effects secondary to amiodarone therapy. Intravenous amiodarone is efficacious and hemodynamically well tolerated in the acute control of heart rote in critically ill patients who develop atrial tachyarrhythmias with rapid ventricular response refractory to conventional treatment. Cardiac electrophysiologic consultation should be obtained before using intravenous amiodarone for this purpose.

The influence of mini-BAL cultures on patient outcomes: implications for the antibiotic management of ventilator-associated pneumonia

STUDY OBJECTIVE

To determine the influence of mini-BAL culture results on subsequent changes in antibiotic therapy and patient outcomes.

DESIGN

Prospective, single-center, cohort study.

SETTING

Medical ICU of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital.

PATIENTS

One hundred thirty mechanically ventilated patients undergoing mini-BAL for suspected ventilator-associated pneumonia (VAP).

INTERVENTIONS

Mini-BAL, prospective patient surveillance, and data collection.

MEASUREMENTS AND RESULTS

Sixty (46.2%) patients had mini-BAL cultures that yielded at least one pathogen potentially accounting for the clinically suspected episode of VAP (64 bacterial, 3 viral, 2 fungal). Among the 60 patients with microbiologically positive mini-BAL cultures, 44 (73.3%) were classified as receiving inadequate antibiotic therapy (ie, identification of a microorganism resistant to the prescribed antibiotic regimen). Prior antibiotic administration or its absence remained unchanged in 51 (39.2%) patients based on the mini-BAL culture results, while in another 51 (39.2%) patients, antibiotic therapy was either begun (n=7) or the existing antibiotic regimen was changed (n=44), and in the remaining 28 (21.6%) patients, antibiotic therapy was discontinued altogether. The hospital mortality rates of these three groups were statistically different: 33.3%, 60.8%, and 14.3%, respectively (p<0.001). The most common pattern of antibiotic resistance resulting in an antibiotic change following mini-BAL was the identification of a Gram-negative bacteria resistant to a prescribed third-generation cephalosporin in 23 of 44 (52.3%) patients. Twenty-one of these 23 patients (91.3%) received prior therapy with a cephalosporin class antibiotic during the same hospitalization. Having an immunocompromised state (adjusted odds ratio [OR]=2.45; 95% confidence interval, 1.56 to 3.85; p=0.047) and the presence of a pathogen in the mini-BAL culture resistant to the empirically prescribed antibiotic regimen (adjusted OR=3.28; 95% confidence interval, 2.12 to 5.06; p=0.006) were identified as risk factors independently associated with hospital mortality by logistic regression analysis.

CONCLUSIONS

These data suggest that antibiotic selection prior to obtaining the results of lower airway cultures is an important determinant of outcome for patients with suspected VAP. A delay in initiating adequate antibiotic therapy was associated with a greater mortality. Therefore, the initial selection of antibiotics for the empiric treatment of VAP should be broad enough to cover all likely pathogens, including antibiotic-resistant bacteria. This appears to be especially important in patients having received prior antibiotics.

Heat shock protein (HSP70) expression in septic patients

PURPOSE

This study investigates heat shock protein 70 (HSP70) expression by peripheral blood mononuclear cells (PBMCs) of septic patients admitted to an intensive care unit and examines the possibility of a correlation between HSP70 levels and plasma tumor necrosis factor alpha (TNF-alpha) concentrations. Additionally, we evaluated whether the HSP70 production could be regarded as a prognostic factor for the development of septic shock as well as for patient survival.

MATERIALS AND METHODS

Blood samples of 29 patients were taken 24 hours after the diagnosis of sepsis. HSP70 expression and TNF-alpha level were measured using indirect immunofluorescent analysis and a commercially available enzyme-linked immunosorbent assay method, respectively.

RESULTS

PBMCs expressed significantly high levels of HSP70 (11.9 +/- 5.6 [sd]) compared with those of the healthy control group (3.2 +/- 2.1% positive cells). Such enhanced levels were correlated to plasma TNF-alpha concentrations (r = .99, P < .01). This study failed to demonstrate a relationship between HSP70 production and clinical outcome.

CONCLUSION

These findings give further evidence that also in humans, heat shock response is activated during sepsis. The correlation observed between HSP70 overproduction and TNF-alpha plasma concentrations suggests that HSP70 exerts a possible protective effect against TNF-alpha cytotoxicity. Such hypothesis has not been confirmed by our clinical data.

Scheduled change of antibiotic classes: a strategy to decrease the incidence of ventilator-associated pneumonia

The purpose of this study was to determine the impact of a scheduled change of antibiotic classes, used for the empiric treatment of suspected gram-negative bacterial infections, on the incidence of ventilator-associated pneumonia and nosocomial bacteremia. Six hundred eighty patients undergoing cardiac surgery were evaluated. During a 6-mo period (i.e., the before-period), our traditional practice of prescribing a third generation cephalosporin (ceftazidime) for the empiric treatment of suspected gram-negative bacterial infections was continued. This was followed by a 6-mo period (i.e., the after-period) during which a quinolone (ciprofloxacin) was used in place of the third-generation cephalosporin. The incidence of ventilator-associated pneumonia was significantly decreased in the after-period (n = 327) compared with the before-period (n = 353) (6.7 versus 11.6%; p = 0.028). This was primarily due to a significant reduction in the incidence of ventilator-associated pneumonia attributed to antibiotic-resistant gram-negative bacteria (0.9 versus 4.0%; p = 0.013). Similarly, we observed a lower incidence of bacteremia attributed to antibiotic-resistant gram-negative bacteria in the after-period compared with the before-period (0.3 versus 1.7%; p = 0.125). These data suggest that a scheduled change of antibiotic classes can reduce the incidence of ventilator-associated pneumonia attributed to antibiotic-resistant gram-negative bacteria.

The intensive care management, mortality and prognostic indicators in severe community-acquired pneumococcal pneumonia

OBJECTIVE

To determine mortality and factors that might predict outcome in severe community-acquired pneumococcal pneumonia treated by a standard protocol.

DESIGN

Prospective, non-concurrent study.

SETTING

Respiratory intensive care unit (ICU) in a teaching hospital.

PATIENTS

63 patients who were diagnosed by positive blood culture or Gram stain and culture of sputum or tracheal aspirate were included.

MEASUREMENTS AND RESULTS

Clinical features, severity scores including Acute Physiology and Chronic Health Evaluation (APACHE) II, organ failure and lung injury scores, and the clinical course in the ICU were documented; 79% of patients required mechanical ventilation. Bacteraemia was present in 34 patients (54%); there were no distinguishing clinical features between bacteraemic and non-bacteraemic cases. The overall mortality was 21%, with only 5 deaths (15% mortality) in the bacteraemic group. Shock and a very low serum albumin (< 26 g/l) were the only clinical features that differentiated survivors from non-survivors; lung injury, APACHE II and multiple organ failure scores were all predictive of outcome. The positive predictive value and specificity in predicting death in individuals for the modified British Thoracic Society rule 1 were 26 and 64%; APACHE II > 2057 and 88%; > 2 organ failure 64 and 92%; and lung injury > 233 and 73%, respectively.

CONCLUSIONS

These results suggest that even in bacteraemic cases mortality should be below 25% with intensive care management and that conventional scoring systems, while predictive of group mortality, are unreliable in individuals.