Intra-abdominal aortic graft infection: prognostic factors associated with in-hospital mortality.

BACKGROUND: Mortality associated with aortic graft infection is considerable. The gold standard for surgical treatment remains explantation of the graft. However, prognostic factors associated with early mortality due to this surgical procedure are not well-known. METHODS: Retrospective analysis of patients admitted in our center between January 2006 and October 2011 for aortic graft infection. The primary endpoint was in-hospital mortality. A bivariate analysis of characteristics of patients associated with in-hospital outcome was performed. RESULTS: Twenty five evaluable patients were studied. All patients were male. Their mean age was 67 ± 8.4 years. Most of them (92%) had severe underlying diseases. An in situ prosthetic graft replacement, mainly using cryopreserved arterial allografts, was performed in all patients, excepted one who underwent extra-anatomic bypass. Causative organisms were identified in 23 patients (92%). The in-hospital mortality rate was 48%. Among pre-operative characteristics, age ≥ 70 years, creatinine ≥ 12 mg/L and C reactive protein ≥ 50 mg/L were significantly associated with in-hospital mortality. Hospital mortality rates increased with the number of risk factor present on ICU admission, and were 0%, 14.3%, 85.7% and 100% for 0, 1, 2 and 3 factors, respectively. The only intra-operative factor associated with prognosis was an associated intestinal procedure due to aorto-enteric fistula. SAPS II, SOFA score and occurrence of medical or surgical complications were postoperative characteristics associated with in-hospital mortality. CONCLUSION: Morbidity and mortality associated with surgical approach of aortic graft infections are considerable. Age and values of creatinine and C Reactive protein on hospital admission appear as the most important determinant of in hospital mortality. They could be taken into account for guiding the surgical strategy.

Outcome and predictors of treatment failure in total hip/knee prosthetic joint infections due to Staphylococcus aureus.

BACKGROUND: Variables associated with the outcome of patients treated for prosthetic joint infections (PJIs) due to Staphylococcus aureus are not well known. METHODS: The medical records of patients treated surgically for total hip or knee prosthesis infection due to S. aureus were reviewed. Remission was defined by the absence of local or systemic signs of implant-related infection assessed during the most recent contact with the patient. RESULTS: After a mean posttreatment follow-up period of 43.6 ± 32.1 months, 77 (78.6%) of 98 patients were in remission. Retention of the infected implants was not associated with a worse outcome than was their removal. Methicillin-resistant S. aureus (MRSA)-related PJIs were not associated with worse outcome, compared with methicillin-susceptible S. aureus (MSSA)-related PJIs. Pathogens identified during revision for failure exhibited no acquired resistance to antibiotics used as definitive therapy, in particular rifampin. In univariate analysis, parameters that differed between patients whose treatment did or did not fail were: American Society of Anesthesiologists (ASA) score, prescription of adequate empirical postsurgical antibiotic therapy, and use of rifampin combination therapy upon discharge from hospital. In multivariate analysis, ASA score ≤2 (odds ratio [OR], 6.87 [95% confidence interval {CI}, 1.45-32.45]; P = .04) and rifampin-fluoroquinolone combination therapy (OR, 0.40 [95% CI, 0.17-0.97]; P = .01) were 2 independent variables associated with remission. CONCLUSIONS: The results of the present study suggest that the ASA score significantly affects the outcome of patients treated for total hip and knee prosthetic infections due to MSSA or MRSA and that rifampin combination therapy is associated with a better outcome for these patients when compared with other antibiotic regimens.

A pilot randomized study comparing high and low volume hemofiltration on vasopressor use in septic shock.

OBJECTIVE: High volume hemofiltration (HVHF) has shown potential benefits in septic animals and a few reports suggested a hemodynamic improvement in humans. However, randomized studies are still lacking. Our goal was to evaluate the hemodynamic effects of HVHF in septic shock patients with acute renal failure (ARF). DESIGN AND SETTING: Prospective randomized study in an intensive care unit (ICU). PATIENTS: Twenty patients with septic shock and ARF. INTERVENTIONS: Patients were randomized to either high volume hemofiltration [HVHF 65 ml/(kg h)] or low volume hemofiltration [LVHF 35 ml/(kg h). Vasopressor dose was adjusted to reach a mean arterial pressure (MAP) > 65 mmHg. MEASUREMENTS AND RESULTS: We performed six hourly measurements of MAP, norepinephrine dose, PaO(2)/FiO(2) and lactate, and four daily urine output and logistic organ dysfunction (LOD) score. Baseline characteristics of the two groups were comparable on randomization. Mean norepinephrine dose decreased more rapidly after 24 h of HVHF treatment compared to LVHF treatment (P = 0.004) whereas lactate and PaO(2)/FiO(2) did not differ between the two treatment groups. During the 4-day follow-up, urine output was slightly increased in the HVHF group (P = 0.059) but the LOD score evolution was not different. Duration of mechanical ventilation, renal replacement therapy and ICU length of stay were also comparable. Survival on day 28 was not affected. CONCLUSION: HVHF decreased vasopressor requirement and tended to increase urine output in septic shock patients with renal failure. However, a larger trial is required to confirm our results and perhaps to show a benefit in survival.

Epidemiology and prognostic factors of critically ill patients treated with hemodiafiltration.

PURPOSE: The objective of this study is to study the epidemiology, outcome, and prognostic factors of critically ill patients treated with continuous venovenous hemodiafiltration (CVVHDF). MATERIALS AND METHODS: Observational cohort was done in a French 16-bed intensive care unit (ICU) from a university-affiliated urban hospital. All patients requiring, in the opinion of the treating physician, the initiation of CVVHDF were included in the study. RESULTS: One hundred ninety-seven patients with acute renal failure (ARF) treated with CVVHDF were studied. The incidence of ARF treated with CVVHDF was 5.9% in the ICU with a mortality rate of 71.6%. A multivariate analysis identified 3 independent factors associated with fatal outcome: mechanical ventilation, sepsis, and septic shock requiring vasoactive drug. In contrast, 2 independent factors predicted a favorable outcome: nonoliguric ARF and serum creatinine concentration higher than 34 mg/L at CVVHDF initiation. A flowchart determined by the chi2 Automatic Interaction and Detection statistical method allowed for the identification of patients' subgroups with different mortality rates ranging from 25% to 100%. CONCLUSIONS: In our series, ARF treated with CVVHDF was associated with a high overall ICU mortality rate (71.6%). However, our prognostic flowchart identified patients with low mortality rates for which renal replacement therapy must be initiated with no discussion as soon as required.

Prevention and treatment of aspiration pneumonia in intensive care units.

Aspiration is a leading cause of nosocomial infection in the intensive care unit. Techniques to avoid or reduce aspiration are important in preventing pneumonia and pneumonitis. The most important preventive measures include the semi-recumbent position, the surveillance of enteral feeding, the use of promotility agents, and avoiding excessive sedation. The analysis of the pathogens involved in these syndromes usually shows a minor role for the anerobes. With regard to treatment, aspiration pneumonitis does not require any antimicrobials; on the contrary, aspiration pneumonia has to be treated. Empiric antimicrobials treatment should be started on clinical suspicion. The choice of the drug has to be guided by local pathogen epidemiology and clinical features; in fact, community type pneumonia requires a first-line antimicrobial such as amoxicillin/clavulanic acid. On the contrary, a nosocomial type of infection needs to be treated as a ventilator-associated pneumonia in agreement with published guidelines. Nevertheless, quantitative culture should be obtained in order to de-escalate antimicrobials. In conclusion, aspiration pneumonia is a frequently encountered disease that can be prevented by relatively simple measures.

Hospital-acquired pneumonia: risk factors for antimicrobial-resistant causative pathogens in critically ill patients.

STUDY OBJECTIVES: To determine factors associated with antimicrobial-resistant hospital-acquired pneumonia (AR-HAP), to build an algorithm evaluating the risk for such a pneumonia, and to test this algorithm. DESIGN: Combined observational and validation cohorts over two periods: January 1994 to December 1999, and January 2000 to March 2001. SETTING: One ICU from a university-affiliated urban teaching hospital. PATIENTS: One hundred twenty-four patients in the observational cohort and 26 patients in the validation cohort exhibiting bacteriologically documented hospital-acquired pneumonia (HAP). INTERVENTIONS: Prospective data collection and multivariate analysis using the chi(2) automatic interaction and detection technique. RESULTS: In the observational cohort, 39 antimicrobial-resistant bacteria were incriminated in 37 patients (30%). Multivariate analysis identified four independent variables allowing a binary stratification of risk. According to the presence or absence of prior antimicrobial treatment, neurologic disturbances on ICU admission, aspiration on ICU admission, and time elapsed between ICU admission and the onset of pneumonia, we were able to identify and separate patients at high, low, or even no risk for acquiring AR-HAP. In the validation cohort, nine antimicrobial-resistant bacteria were incriminated in nine patients (34.6%). In this cohort, the algorithm performed well allowing the identification of null risk categories: the absence of prior antimicrobial treatment, the presence of prior antimicrobial treatment with neurologic disturbances on ICU admission and an early-onset pneumonia, and the presence of prior antimicrobial treatment without neurologic disturbances but with aspiration on ICU admission were always associated with antimicrobial-susceptible HAP. CONCLUSION: We developed and tested a binary algorithm allowing the identification of patients at low risk for acquiring AR-HAP. An antibiotic strategy including an initial antimicrobial treatment guided by such an algorithm, followed, if possible, by a de-escalation when antimicrobial data are available, could increase the administration of adequate initial antimicrobial treatment and help prevent the emergence of antibiotic resistance in the ICU.

Impact of adequacy of initial antimicrobial therapy on the prognosis of patients with ventilator-associated pneumonia.

OBJECTIVE: To study the prognostic impact of the appropriateness of initial antimicrobial therapy in patients suffering from ventilator-associated pneumonia (VAP). DESIGN AND SETTING: Observational cohort from January 1994 to December 2001 in one intensive care unit (ICU) from an university-affiliated, urban teaching hospital. PATIENTS: All 132 consecutive patients exhibiting bacteriologically documented VAP during ICU stay. MEASUREMENTS AND RESULTS: Initial antimicrobial treatment was deemed appropriate when the period from initial VAP diagnosis and subsequent administration of antibiotics was within 24 h and all causative pathogens were in vitro susceptible to at least one of the antibiotics of the regimen. Such a treatment was present in 106 episodes. Fifty-eight patients died. In bivariate analysis an appropriate initial antimicrobial therapy was associated with a significantly lower mortality rate (40% vs. 62%). In multivariate analysis the three independent factors present upon VAP onset and associated with death were pulmonary involvement of more than a single lobe on chest radiograph, platelet count less than 150000/mm(3), and Simplified Acute Physiology Score II higher than 37. Appropriate antimicrobial therapy was associated with a nonsignificant trend toward a lower mortality. CONCLUSIONS: In our cohort the mortality rate was lower in patients suffering from VAP when the initial antimicrobial therapy was appropriate. However, such a factor did not appear as an independent prognostic factor.

Hospital-acquired pneumonia in critically ill patients: mortality risk stratification upon onset.

STUDY OBJECTIVES: To identify, in patients experiencing hospital-acquired pneumonia (HAP), prognostic factors present at disease onset and build an algorithm capable of stratifying mortality risk upon HAP onset. DESIGN: Observational cohort from January 1994 to December 2001. SETTING: One intensive care unit (ICU) from a university-affiliated, urban teaching hospital. PATIENTS: All consecutive patients exhibiting bacteriologically documented HAP either on ICU admission or during ICU stay. INTERVENTIONS: Data collection and multivariate analysis using Chi-Square Automatic Interaction and Detection technique. RESULTS: 168 patients were studied. The overall mean mortality rate was 49.4%. Upon onset of HAP, five independent variables allowed binary stratification of mortality risk. These consisted of underlying diseases (nonfatal versus ultimately and rapidly fatal diseases), Simplified Acute Physiology Score II (less than versus > or =37), platelet count (less than versus > or =150,000/mm3), chest x-ray involvement (1 versus >1 lobe), and PaO2/FiO2 (less than versus > or =167 mm Hg). A branching algorithm consisting of these five variables identified patients with HAP at both low (<35%) and high (>75%) risk of mortality. CONCLUSION: Mortality in ICU patients with HAP may be predicted early, upon onset of HAP, by the cumulative use of prognostic factors in an algorithm.