Relative adrenal insufficiency in patients with severe acute pancreatitis.

OBJECTIVE: Inadequate cortisol levels and adrenal dysfunction may play a role in the pathophysiology of severe acute pancreatitis. This study aimed to analyse the incidence of relative adrenal insufficiency (RAI) in these patients, to identify factors associated with RAI and to describe how adrenal responsiveness affects outcome. DESIGN: Prospective observational multicenter study. PATIENTS: Twenty-five patients with severe acute pancreatitis. INTERVENTIONS: A short Synacthen test (SST) was performed within 5 days after admission to the hospital. The incidence of RAI, defined as an increment after SST of less than 9 microg/dl was the primary endpoint of the study. Serum cortisol was measured at baseline and at 30 and 60 min after administration of 250 microg adrenocorticotropic hormone. MEASUREMENTS AND RESULTS: Median baseline cortisol level was 26.6 microg/dl, and increased to 43.2 microg/dl and 48.8 microg/dl after 30 min and 60 min respectively. RAI was found in 16% of all patients and in 27% of patients with organ dysfunction. Patients with RAI were more severely ill and had higher SOFA scores from days 4 to 7 after admission. All patients with RAI developed pancreatic necrosis, and all of them needed surgical intervention. Twenty-eight-day mortality was significantly higher in patients with RAI (75% vs. 5%, p =0.007). Patients who died had a lower increment in cortisol levels after the SST than patients who survived. CONCLUSION: RAI is frequent in patients with severe acute pancreatitis and organ dysfunction. It occurs in patients with more severe pancreatitis and is associated with increased mortality.

Clinical relevance of Aspergillus isolation from respiratory tract samples in critically ill patients.

INTRODUCTION: The diagnosis of invasive pulmonary aspergillosis, according to the criteria as defined by the European Organisation for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG), is difficult to establish in critically ill patients. The aim of this study is to address the clinical significance of isolation of Aspergillus spp. from lower respiratory tract samples in critically ill patients on the basis of medical and radiological files using an adapted diagnostic algorithm to discriminate proven and probable invasive pulmonary aspergillosis from Aspergillus colonisation. METHODS: Using a historical cohort (January 1997 to December 2003), all critically ill patients with respiratory tract samples positive for Aspergillus were studied. In comparison to the EORTC/MSG criteria, a different appreciation was given to radiological features and microbiological data, including semiquantitative cultures and direct microscopic examination of broncho-alveolar lavage samples. RESULTS: Over a 7 year period, 172 patients were identified with a positive culture. Of these, 83 patients were classified as invasive aspergillosis. In 50 of these patients (60%), no high risk predisposing conditions (neutropenia, hematologic cancer and stem cell or bone marrow transplantation) were found. Typical radiological imaging (halo and air-crescent sign) occurred in only 5% of patients. In 26 patients, histological examination either by ante-mortem lung biopsy (n = 10) or necropsy (n = 16) was performed, allowing a rough estimation of the predictive value of the diagnostic algorithm. In all patients with histology, all cases of clinical probable pulmonary aspergillosis were confirmed (n = 17). Conversely, all cases classified as colonisation had negative histology (n = 9). CONCLUSION: A respiratory tract sample positive for Aspergillus spp. in the critically ill should always prompt further diagnostic assessment, even in the absence of the typical hematological and immunological host risk factors. In a minority of patients, the value of the clinical diagnostic algorithm was confirmed by histological findings, supporting its predictive value. The proposed diagnostic algorithm needs prospective validation.

Clinical and economic outcomes in critically ill patients with nosocomial catheter-related bloodstream infections.

BACKGROUND: Central venous catheters are universally used during the treatment of critically ill patients. Their use, however, is associated with a substantial infection risk, potentially leading to increased mortality and costs. We evaluate clinical and economic outcomes associated with nosocomial central venous catheter-related bloodstream infection (CR-BSI) in intensive care unit (ICU) patients. METHODS: A retrospective (1992-2002), pairwise-matched (ratio of case patients to control subjects, 1:2 or 1:1), risk-adjusted cohort study was performed at a 54-bed general ICU at a university hospital. ICU patients with microbiologically documented CR-BSI (n = 176) were matched with control subjects (n = 315) on the basis of disease severity, diagnostic category, and length of ICU stay (equivalent or longer) before the onset of CR-BSI in the index case patient. Clinical outcome was principally evaluated by in-hospital mortality. Economic outcome was evaluated on the basis of duration of mechanical ventilation, length of ICU and hospital stays, and total hospital costs, as derived from the patient's hospital invoices. RESULTS: The attributable mortality rate for CR-BSI was estimated to be 1.8% (95% confidence interval, -6.4% to 10.0%); in-hospital mortality rates for patients with CR-BSI and matched control subjects were 27.8% and 26.0%, respectively. CR-BSI was associated with significant excesses in duration of mechanical ventilation, duration of ICU and hospital stays, and a significant increase in total hospital cost. Linear regression analysis with adjustment for duration of hospitalization and clinical covariates, revealed that CR-BSI is independently associated with higher costs. CONCLUSIONS: In ICU patients, CR-BSI does not result in increased mortality. It is, however, associated with a significant economic burden, emphasizing the importance of continuous efforts in prevention.

Phenytoin intoxication in critically ill patients.

Phenytoin intoxication can result in major and possibly life-threatening disorders. Furthermore, the hepatic clearance can become saturated, thus, shifting the elimination from first- to zero-order kinetics. This results in a slow elimination of the compound in case of intoxication. The treatment modalities for phenytoin overdose are limited. Taking into account the high level of protein binding, the molecule is not easily eliminated from the body by means of extracorporal epuration. Although reports exist on the use of MARS (molecular adsorbents recirculating system) dialysis, peritoneal dialysis, and standard dialysis for the elimination, in practice, hemoperfusion, is the most often applied technique. The authors report the case of a hypoalbuminemic patient with severe neurologic signs of phenytoin intoxication (total concentration moderately elevated, free fraction high). A combination of high-flux dialysis and hemoperfusion resulted in a considerable extraction of the drug, accelerating the natural clearance from the body and ameliorating clinical signs of intoxication. In selected patients (with a high free fraction of phenytoin), high-flux dialysis may be a valuable alternative or adjuvant to hemoperfusion.

Influence of matching for exposure time on estimates of attributable mortality caused by nosocomial bacteremia in critically ill patients.

OBJECTIVE: To evaluate the influence of matching on exposure time on estimates of attributable mortality of nosocomial bacteremia as assessed by matched cohort studies. DESIGN: Two retrospective, pairwise-matched (1:2) cohort studies. SETTING: A 54-bed intensive care unit (ICU) in a university hospital. PATIENTS: Patients with nosocomial Escherichia coli bacteremia (n = 68) and control-patients without nosocomial bacteremia (n = 136 for each matched cohort study). INTERVENTION: In both matched cohort studies, the same set of bacteremic patients was matched with control-patients using the APACHE II system. In the first study, control-patients were required to have an ICU stay at least as long as the respective bacteremic patient prior to onset of bacteremia (matching on exposure time). In the second study, control-patients were required to have an ICU stay shorter than the stay prior to the development of bacteremia in the respective bacteremic patient (no matching on exposure time). RESULTS: For bacteremic patients, the mean ICU stay before onset of the bacteremia was 9 days (median, 6 days). In the first matched cohort study, hospital mortality was not different between bacteremic patients and control-patients (44.1% vs 43.4%; P = .999). In the second study, mortality of bacteremic patients and control-patients was also not different (44.1% vs 47.8%; P = .657). Mortality rates between control groups were not different (43.4% vs 47.8%; P = .543). CONCLUSION: Matching or not matching on exposure time did not alter the estimate of attributable mortality for ICU patients with E. coli bacteremia.

Colonization status and appropriate antibiotic therapy for nosocomial bacteremia caused by antibiotic-resistant gram-negative bacteria in an intensive care unit.

OBJECTIVE: Timely initiation of antibiotic therapy is crucial for severe infection. Appropriate antibiotic therapy is often delayed for nosocomial infections caused by antibiotic-resistant bacteria. The relationship between knowledge of colonization caused by antibiotic-resistant gram-negative bacteria (ABR-GNB) and rate of appropriate initial antibiotic therapy for subsequent bacteremia was evaluated. DESIGN: Retrospective cohort study. SETTING: Fifty-four-bed intensive care unit (ICU) of a university hospital. In this unit, colonization surveillance is performed through routine site-specific surveillance cultures (urine, mouth, trachea, and anus). Additional cultures are performed when presumed clinically relevant. PATIENTS: ICU patients with nosocomial bacteremia caused by ABR-GNB. RESULTS: Infectious and microbiological characteristics and rates of appropriate antibiotic therapy were compared between patients with and without colonization prior to bacteremia. Prior colonization was defined as the presence (detected > or = 2 days before the onset of bacteremia) of the same ABR-GNB in colonization and subsequent blood cultures. During the study period, 157 episodes of bacteremia caused by ABR-GNB were suitable for evaluation. One hundred seventeen episodes of bacteremia (74.5%) were preceded by colonization. Appropriate empiric antibiotic therapy (started within 24 hours) was administered for 74.4% of these episodes versus 55.0% of the episodes that occurred without prior colonization. Appropriate therapy was administered within 48 hours for all episodes preceded by colonization versus 90.0% of episodes without prior colonization. CONCLUSION: Knowledge of colonization status prior to infection is associated with higher rates of appropriate therapy for patients with bacteremia caused by ABR-GNB.

Documented and clinically suspected bacterial infection precipitating intensive care unit admission in patients with hematological malignancies: impact on outcome.

OBJECTIVE: To assess the impact of documented and clinically suspected bacterial infection precipitating ICU admission on in-hospital mortality in patients with hematological malignancies. DESIGN AND SETTING: Prospective observational study in a 14-bed medical ICU at a tertiary university hospital. PATIENTS: A total of 172 consecutive patients with hematological malignancies admitted to the ICU for a life-threatening complication over a 4-year period were categorized into three main groups according to their admission diagnosis (documented bacterial infection, clinically suspected bacterial infection, nonbacterial complications) by an independent panel of three physicians blinded to the patient's outcome and C-reactive protein levels. RESULTS: In-hospital and 6-months mortality rates in documented bacterial infection (n=42), clinically suspected bacterial infection (n=40) vs. nonbacterial complications (n=90) were 50.0% and 42.5% vs. 65.6% (p=0.09 and 0.02) and 56.1% and 48.7% vs. 72.1% (p=0.11 and 0.02), respectively. Median baseline C-reactive protein levels in the first two groups were 23 mg/dl and 21.5 mg/dl vs. 10.7 mg/dl (p<0.001 and p=0.001) respectively. After adjustment for the severity of critical and underlying hematological illness and the duration of hospitalization before admission documented (OR 0.20; 95% CI 0.06-0.62, p=0.006) and clinically suspected bacterial infection (OR 0.18; 95% CI 0.06-0.53, p=0.002) were associated with a more favorable outcome than nonbacterial complications. CONCLUSIONS: Severely ill patients with hematological malignancies admitted to the ICU because of documented or clinically suspected bacterial infection have a better outcome than those admitted with nonbacterial complications. These patients should receive advanced life-supporting therapy for an appropriate period of time.

Intra-abdominal hypertension in patients with severe acute pancreatitis.

INTRODUCTION: Abdominal compartment syndrome has been described in patients with severe acute pancreatitis, but its clinical impact remains unclear. We therefore studied patient factors associated with the development of intra-abdominal hypertension (IAH), the incidence of organ failure associated with IAH, and the effect on outcome in patients with severe acute pancreatitis (SAP). METHODS: We studied all patients admitted to the intensive care unit (ICU) because of SAP in a 4 year period. The incidence of IAH (defined as intra-abdominal pressure >or= 15 mmHg) was recorded. The occurrence of organ dysfunction during ICU stay was recorded, as was the length of stay in the ICU and outcome. RESULTS: The analysis included 44 patients, and IAP measurements were obtained from 27 patients. IAH was found in 21 patients (78%). The maximum IAP in these patients averaged 27 mmHg. APACHE II and Ranson scores on admission were higher in patients who developed IAH. The incidence of organ dysfunction was high in patients with IAH: respiratory failure 95%, cardiovascular failure 91%, and renal failure 86%. Mortality in the patients with IAH was not significantly higher compared to patients without IAH (38% versus 16%, p = 0.63), but patients with IAH stayed significantly longer in the ICU and in the hospital. Four patients underwent abdominal decompression because of abdominal compartment syndrome, three of whom died in the early postoperative course. CONCLUSION: IAH is a frequent finding in patients admitted to the ICU because of SAP, and is associated with a high occurrence rate of organ dysfunction. Mortality is high in patients with IAH, and because the direct causal relationship between IAH and organ dysfunction is not proven in patients with SAP, surgical decompression should not routinely be performed.

Relationship between fluid status and its management on acute renal failure (ARF) in intensive care unit (ICU) patients with sepsis: a prospective analysis.

BACKGROUND: Sepsis carries a high morbidity and mortality, further enhanced by acute renal failure (ARF). Although fluid loading can prevent ARF in dehydrated patients, this approach could be risky in septic patients, since it can deteriorate oxygenation. This study evaluates the relationship between fluid status and management and ARF development in septic patients. METHODS AND PATIENTS: Patients admitted to the ICU between 1 January 2001 and 31 December 2001 were included if serum creatinine (Cr) was <2 mg% on admission, and if they developed sepsis. ARF was determined as a doubling of serum Cr, an increase of serum Cr >2 mg%, or oliguria <500 ml/24 hr. RESULTS: 257 out of 2442 patients, admitted to the intensive care unit (ICU), developed sepsis, 29 developed ARF, 13 needed a renal replacement. ARF vs. non-ARF patients were older (65.2 +/- 13.3 vs. 55.1 +/- 17.4, p=0.002), had a higher central venous pressure (CVP) at day 1 (9.6 +/- 4.3 vs. 5.2 +/- 3.6 mmHg, p<0.001), and at day 2 (7.1 +/- 5.1 vs. 5.1 +/- 4.0 mmHg, p=0.03), a higher colloid fluid loading for the first 3 days (2037 +/- 1681 vs. 1116 +/- 1220 mL, p<0.03), a higher serum Cr (1.25 +/- 0.39 vs. 0.96 +/- 0.33 mg/dL, p=0.009) and an increase vs. a decrease in serum Cr during the first 24 hr (+0.30 +/- 0.58 vs. -0.31 +/- 0.45 mg/dL, p=0.02), a lower diuresis (1347 +/- 649 vs. 1849 +/- 916 mL, p=0.005). There was no difference in APACHE II scores (19.2 +/- 7.2 vs. 17.2 +/- 6.6, p=0.1), or MAP (64.5 +/- 12.4 vs. 67.9 +/- 12.4, p=0.18). The fraction of inspired oxygen (FiO2) need in the ARF group increased from 40.4 +/- 11.5 to 65.6 +/- 24.2% from day 1 to day 2 (p=0.04), where it remained unchanged in the non-ARF group. The use of diuretics was higher in the ARF group (21/29 vs. 43/228, p=0.001). CONCLUSION: Septic patients developing ARF have an elevated CVP at day 1 of sepsis, indicating cardiodepression or intrarenal causes for hypoperfusion. These patients develop ARF despite further fluid loading. Respiratory function deteriorated in patients with ARF. Persistent fluid challenges should be avoided if they do not lead to an improvement in renal function, or if oxygenation deteriorates.

Sodium bicarbonate versus THAM in ICU patients with mild metabolic acidosis.

BACKGROUND: Sodium bicarbonate is despite its side effects, considered the standard alkali therapy in metabolic acidosis. THAM is an alternative alkalizing agent; however, there are limited data on the use of THAM in metabolic acidosis. The aim of this study was to compare the efficacy and adverse effects of a single dose of sodium bicarbonate and THAM in intensive care unit (ICU) patients with mild metabolic acidosis. METHODS: 18 adult ICU patients with mild metabolic acidosis (serum bicarbonate < 20 mmol/L) were randomized to a single dose of either sodium bicarbonate or THAM, administered over a 1-hour period, and titrated to buffer the excess of acid load. RESULTS: Sodium bicarbonate and THAM had equivalent alkalinizing effect during the infusion period. This was still present 4 hours after start of infusion of sodium bicarbonate, and until 3 hours after start of infusion of THAM. Serum potassium levels decreased after sodium bicarbonate infusion, and remained unchanged after THAM. After sodium bicarbonate, sodium increased, and after THAM, serum sodium decreased. CONCLUSIONS: Sodium bicarbonate and THAM had a similar alkalinizing effect in patients with mild metabolic acidosis; however, the effect of sodium bicarbonate was longer lasting. Sodium bicarbonate did decrease serum potassium, and THAM did not; THAM is therefore not recommended in patient with hyperkalemia. As sodium bicarbonate leads to an increase of serum sodium and THAM to a decrease, THAM may be the alkalinizing agent of choice in patients with hypernatremia. Similarly, because sodium bicarbonate increases PaCO2 and THAM may even decrease PaCO2, sodium bicarbonate is contraindicated and THAM preferred in patients with mixed acidosis with high PaCO2 levels.

Outcome and attributable mortality in critically Ill patients with bacteremia involving methicillin-susceptible and methicillin-resistant Staphylococcus aureus.

BACKGROUND: Staphylococcus aureus bacteremia carries high mortality rates. The clinical impact of methicillin resistance remains controversial: outcome comparisons between patients with bacteremia involving methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) S aureus are difficult to perform because of important differences in severity of illness. METHODS: A retrospective cohort analysis and 2 independent case-control analyses were performed to determine and compare outcomes and attributable mortality rates of MSSA (n = 38) and MRSA bacteremia (n = 47) in critically ill patients. For the case-control studies, matching (1:2 ratio) was based on the APACHE (Acute Physiology and Chronic Health Evaluation) II classification: APACHE II score (+/-1 point) and diagnostic category. RESULTS: Patients with MRSA bacteremia had more acute renal failure and hemodynamic instability than patients with MSSA bacteremia. They had a longer intensive care unit stay and ventilator dependency. Patients with MRSA bacteremia had a higher 30-day mortality rate (53.2% vs 18.4%) and in-hospital mortality rate (63.8% vs 23.7%) (P<.05). Multivariate survival analysis demonstrated acute renal failure, length of mechanical ventilation, age, and methicillin resistance to be independently associated with mortality (P<.05). The attributable mortality rate for MSSA bacteremia was 1.3%: mortality rates for cases and controls were respectively 23.7% and 22.4% (P =.94). The attributable mortality rate for MRSA bacteremia was 23.4%: mortality rates for cases and controls were respectively 63.8% and 40.4% (P =.02). The difference (22.1%) between both attributable mortality rates was significant (95% confidence interval, 8.8%-35.3%). CONCLUSION: In critically ill patients, after accurate adjustment for disease severity and acute illness, we found MRSA bacteremia to have a higher attributable mortality than MSSA bacteremia.

Nosocomial bacteremia caused by antibiotic-resistant gram-negative bacteria in critically ill patients: clinical outcome and length of hospitalization.

Population characteristics and outcomes were retrospectively compared for critically ill patients with nosocomial bacteremia caused by antibiotic-susceptible (AB-S; n=208) or antibiotic-resistant (AB-R; n=120) gram-negative bacteria. No significant differences in severity of illness and comorbidity factors were seen between groups. Patients with bacteremia caused by AB-R strains had a longer hospitalization before the onset of the bacteremia. The in-hospital mortality for patients with bacteremia caused by AB-S strains was 41.8%; for patients infected with AB-R strains, it was 45.0% (P=.576). A multivariate survival analysis demonstrated that older age (P=.009), a high-risk source of bacteremia (abdominal and lower respiratory tract; P=.031), and a high acute physiology and chronic health evaluation II-related expected mortality (P=.032) were independently associated with in-hospital mortality (P<.05). Antibiotic resistance in nosocomial bacteremia caused by gram-negative bacteria does not adversely affect the outcome for critically ill patients.

Effects of nosocomial candidemia on outcomes of critically ill patients.

PURPOSE: To determine whether nosocomial candidemia is associated with increased mortality in intensive care unit (ICU) patients. SUBJECTS AND METHODS: We performed a retrospective (1992 to 2000) cohort study of 73 ICU patients with candidemia and 146 matched controls. Controls were matched based on disease severity as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II score (+/- 1 point), diagnostic category, and length of ICU stay before onset of candidemia. RESULTS: In comparison with the control group, patients with candidemia developed more acute respiratory failure (97% [n = 71] vs. 88% [n = 129], P = 0.03) during their ICU stay. They were mechanically ventilated for a longer period (29 +/- 26 days vs. 19 +/- 19 days, P<0.01) and had a longer stay in the ICU (36 +/- 33 days vs. 25 +/- 23 days, P = 0.02) as well as in the hospital (77 +/- 81 days vs. 64 +/- 69 days, P = 0.04). There was no difference in in-hospital mortality between the groups (48% [n = 35] vs. 43% [n = 62], P = 0.44), a difference of 5% (95% confidence interval [CI]: -8% to 19%). In a multivariate analysis, older age (hazard ratio [HR] = 1.13 per 10 years; 95% CI: 1.04 to 1.23; P = 0.004), acute renal failure (HR = 1.4; 95% CI: 1.1 to 2.0; P = 0.02), and unfavorable APACHE II scores (HR = 1.10 per 5 points; 95% CI: 1.00 to 1.20; P = 0.05) were independent predictors of mortality. Candidemia was not associated with mortality in a model that adjusted for these factors (HR = 0.9; 95% CI: 0.7 to 1.2; P = 0.53). CONCLUSION: Nosocomial candidemia does not adversely affect the outcome in ICU patients in whom mortality is attributable to age, the severity of underlying disease, and acute illness.

Clinical characteristics of patients developing ARF due to sepsis/systemic inflammatory response syndrome: results of a prospective study.

BACKGROUND: Acute renal failure (ARF) in patients with sepsis provokes high mortality and financial cost. In this prospective study, we collected characteristics of patients in the intensive care unit (ICU) who developed sepsis/systemic inflammatory response syndrome (SIRS) to analyze differences between those who subsequently did or did not develop ARF. METHODS: All patients admitted to the ICU of the University Hospital Gent, Belgium, between January 1, 2001, and December 31, 2001, who developed sepsis/SIRS were included if they had a serum creatinine level less than 2 mg/dL (<177 micromol/L). RESULTS: Of 2,442 patients admitted to the ICU, 257 patients developed sepsis/SIRS. Of those, 29 patients (11%) developed ARF. In a univariate analysis, age, central venous pressure (CVP), and serum creatinine and blood urea nitrogen levels were greater (P = 0.003, P = 0.006, P < 0.001, and P < 0.001, respectively), whereas mean arterial and diastolic blood pressures, 24-hour urinary output, arterial pH, bicarbonate level, thrombocyte count, albumin level, and prothrombin time were lower (P = 0.05, P = 0.004, P = 0.005, P = 0.03, P = 0.009, P = 0.037, P = 0.05, and P = 0.006, respectively) in the ARF group. Prevalence of diabetes, sex, and need for ventilation were not different between the ARF and no-ARF groups, but in the ARF group, diuretic use, vasopressor use, and presence of primary hepatic failure were more prevalent (P = 0.001 for each). In a multivariate analysis, age, serum creatinine level, CVP, and presence of liver failure significantly contributed to a logistic regression model for ARF. CONCLUSION: Several parameters already were disturbed at the first day of SIRS/sepsis in patients who later developed ARF. Older age, elevated serum creatinine level despite elevated CVP, and presence of hepatic failure are predictive for ARF in septic patients.

Evaluation of outcome in critically ill patients with nosocomial enterobacter bacteremia: results of a matched cohort study.

STUDY OBJECTIVE: To evaluate the clinical impact of nosocomial Enterobacter bacteremia in critically ill patients. DESIGN: Retrospective (January 1992 to December 2000) matched cohort study. SETTING: Fifty-four-bed ICU (including medical, surgical, cardiosurgical ICU, and burns unit) from a university hospital. PATIENTS: Sixty-seven ICU patients with Enterobacter bacteremia (case patients) and 134 control patients. INTERVENTION: Matching of control patients (1:2 ratio) was on the basis of the APACHE (acute physiology and chronic health evaluation) II system. As expected, mortality can be derived from this severity-of-disease classification system; this matching procedure results in an equal expected mortality rate for patients with Enterobacter bacteremia and control patients. RESULTS: The overall rate of appropriate antibiotic therapy in patients with Enterobacter bacteremia was high (96%) and initiated soon after the onset of the bacteremia (0.5 +/- 0.9 days). Patients with Enterobacter bacteremia had more hemodynamic instability (p = 0.015), longer ICU stay (p < 0.001), and ventilator dependence (p < 0.001). No differences between case and control patients were found in age (52 years vs 53 years, p = 0.831), prevalence of acute renal failure (16% vs 16%, p = 0.892), and acute respiratory failure (93% vs 84%, respectively; p = 0.079). In-hospital mortality rates for case and control patients were not different (34% vs 39%, respectively; p = 0.536). CONCLUSION: After accurate adjustment for severity of underlying disease and acute illness, no difference was found between ICU patients with Enterobacter bacteremia and matched control patients. In the presence of fast and appropriate antibiotic therapy, Enterobacter bacteremia does not adversely affect the outcome in ICU patients.

Outcome in noninvasively and invasively ventilated hematologic patients with acute respiratory failure.

STUDY OBJECTIVES: The survival rate of patients with a hematologic malignancy requiring mechanical ventilation (MV) in the ICU has improved over the last few decades. The objective of this study was to identify the factors affecting the in-hospital mortality of these particular patients, and to assess whether the use of noninvasive positive pressure ventilation (NPPV) was protective in our study population. DESIGN: We retrospectively collected variables in 166 consecutive patients with hematologic malignancies who had acute respiratory failure (ARF) requiring MV, and identified factors obtained within 24 h of ICU admission affecting in-hospital mortality in univariate and multivariate stepwise logistic regression analyses. The effect of NPPV on mortality was assessed using a pair-wise matched exposed-unexposed analysis. RESULTS: The mean simplified acute physiology score (SAPS) II was 58.9. The in-hospital mortality rate was 71%. In a multivariate logistic regression analysis, the in-hospital mortality rate was predicted by increasing severity of illness, as measured by SAPS II (odds ratio [OR] per point of increase, 1.07; 95% confidence interval [CI], 1.04 to 1.11) and a diagnosis of acute myelogenous leukemia (OR, 2.73; 95% CI, 1.05 to 7.11). Female sex (OR, 0.36; 95% CI, 0.16 to 0.82), endotracheal intubation (ETI) within 24 h of ICU admission (OR, 0.29; 95% CI, 0.11 to 0.78), and recent bacteremia (defined as blood cultures positive for bacteria < 48h before or < 24h after ICU admission) [OR, 0.22; 95% CI, 0.08 to 0.61] were associated with a lower mortality rate. Twenty-seven patients who received NPPV were matched for SAPS II (+/- 3) with 52 patients who required immediate ETI on a 1:2 basis. The crude in-hospital mortality rate was 65.4% in both groups. CONCLUSION: Although the in-hospital mortality rate in hematologic patients who develop ARF remains high, the reluctance to intubate and start treatment with invasive MV in this population is unjustified, especially when bacteremia has precipitated ICU admission.

Absence of excess mortality in critically ill patients with nosocomial Escherichia coli bacteremia.

OBJECTIVE: To evaluate excess mortality in critically ill patients with Escherichia coli bacteremia after adjustment for severity of illness. DESIGN: Retrospective (1992-2000), pairwise-matched (1:2), risk-adjusted cohort study. SETTING: Fifty-four-bed ICU in a university hospital including a medical and surgical ICU, a unit for care after cardiac surgery, and a burns unit. PATIENTS: ICU patients with nosocomial E. coli bacteremia (defined as cases; n = 64) and control-patients without nosocomial bloodstream infection (n = 128). METHODS: Case-patients were matched with control-patients on the basis of the Acute Physiology and Chronic Health Evaluation (APACHE) II system: an equal APACHE II score (+/- 2 points) and diagnostic category. In addition, control-patients were required to have an ICU stay at least as long as that of the respective case-patients prior to onset of the bacteremia. RESULTS: The overall rate of appropriate antibiotic therapy in patients with E. coli bacteremia was high (93%) and such therapy was initiated soon after onset of the bacteremia (0.6 +/- 1.0 day). ICU patients with E. coli bacteremia had more acute renal failure. No differences were noted between case-patients and control-patients in incidence of acute respiratory failure, hemodynamic instability, or age. No differences were observed in length of mechanical ventilation or length of ICU stay. In-hospital mortality rates for cases and controls were not different (43.8% and 45.3%, respectively; P = .959). CONCLUSION: After adjustment for disease severity and acute illness and in the presence of adequate antibiotic therapy, no excess mortality was found in ICU patients with E. coli bacteremia.

Nosocomial bacteremia involving Acinetobacter baumannii in critically ill patients: a matched cohort study.

OBJECTIVE: To determine outcome and attributable mortality in critically ill patients with nosocomial bacteremia involving A. baumannii. DESIGN: A retrospective matched cohort study in which all ICU patients with microbiologically documented A. baumannii bacteremia were defined as cases. Matching of the controls was based on equivalent APACHE II score (+/-2 points) and diagnostic category. Control patients were required to have an ICU stay equivalent to or longer than the case prior to onset of the bacteremia. SETTING: The 54-bed ICU of the 1060-bed Ghent University Hospital. PATIENTS: 45 ICU patients with A. baumannii bacteremia and 90 matched control subjects without clinical or microbiological evidence of blood stream infection. MEASUREMENTS: Population characteristics and in-hospital mortality rates of patients with A. baumannii bacteremia and their controls were compared. Attributable mortality is determined by subtracting the crude mortality rate of the controls from the crude mortality rate of the cases. RESULTS: Patients with A. baumannii bacteremia had significantly more hemodynamic instability, longer ICU stay, and longer length of ventilator dependence than controls. In-hospital mortality rates for cases and controls were, respectively, 42.2% and 34.4%; thus the attributable mortality was 7.8%. CONCLUSION: In critically ill patients A. baumannii bacteremia is not associated with a significantly increased mortality rate.

The use of the activated clotting time for monitoring heparin therapy in critically ill patients.

OBJECTIVE: To determine the correlation between activated clotting time (ACT) and activated partial thromboplastin time (aPTT) in patients receiving intravenous unfractionated heparin therapy, and the accuracy of the ACT in predicting the level of anticoagulation. DESIGN: Paired aPTT and ACT measurements were obtained from a convenience sample of critically ill patients requiring intravenous unfractionated heparin. The aPTT was determined in the hospital laboratory and ACT measurements were performed with a portable device. SETTING: The intensive care unit of Ghent University Hospital, a tertiary care facility with 54 beds. PATIENTS AND PARTICIPANTS: Twenty-eight patients were studied prospectively; a total of 105 paired samples were obtained. The indication for heparin therapy was cerebral ischemia in 8, various cardiac conditions in 10, pulmonary embolism in 3, continuous hemofiltration in 3, and peripheral arterial thrombosis in 4. RESULTS: There was a significant correlation between aPTT and ACT. Analysis of variance showed a significant difference in ACT between different levels of anticoagulation, aPTT shorter than 60 s (group 1), aPTT 60-90 s (group 2), and aPTT longer than 90 s (group 3): 142+/-16.7 s in group 1 vs. 155+/-29.6 and 192+/-39.1 in groups 2 and 3. CONCLUSIONS: The correlation between the aPTT and the ACT in this ICU setting is poor; ACT cannot differentiate between low and therapeutic levels of anticoagulation. The use of the ACT for monitoring low to moderate doses of heparin in ICU patients cannot be recommended.

Emergence of antibiotic resistance in infected pancreatic necrosis.

BACKGROUND: Overall, the use of antibiotics in the treatment of patients with severe acute pancreatitis has increased owing to the use of antibiotic prophylaxis. HYPOTHESIS: The incidence of antibiotic-resistant (AB-R) bacteria in infected pancreatitis is related to prolonged antibiotic treatment and may affect outcome. DESIGN: Case series. SETTING: Fifty-six-bed intensive care unit of a tertiary care center. PATIENTS: Forty-six consecutive patients with infected pancreatic necrosis. MAIN OUTCOME MEASURES: Occurrence rate of AB-R organisms in pancreatic infection, overall duration of antibiotic treatment prior to infection, and mortality, defined as inhospital mortality. RESULTS: Infection with AB-R microorganisms was found in 24 (52%) of 46 patients. Primary infection was present in 7 patients; in 21 patients, nosocomial surinfection with AB-R organisms occurred. Patients with AB-R infections were treated with antibiotics for a longer period (24 vs 15 days, P<.05), while disease severity and the incidence of organ failure were not statistically significantly different. The intensive care unit stay was significantly longer in patients with AB-R infections (23 vs 31 days, P = .02). Mortality was not statistically significantly different in patients with AB-R infections (37% vs 28%, P = .23). CONCLUSIONS: The occurrence rate of infections with AB-R organisms in our patients with severe acute pancreatitis was high and was associated with a longer intensive care unit stay, but no increased mortality could be demonstrated. The duration of antibiotic treatment was increased in patients in whom AB-R infections developed.