Red blood cell transfusions and nosocomial infections in critically ill patients

OBJECTIVE: A previous retrospective evaluation of Project Impact data demonstrated an association between red blood cell transfusions, nosocomial infections, and poorer outcomes in critically ill patients, independent of survival probability or patient age. The objective of this study was to determine whether transfused patients, independent of survival probability based on Mortality Prediction Model scores, have higher nosocomial infection rates, longer intensive care unit and hospital lengths of stay, and higher mortality rates than nontransfused patients. DESIGN: Prospective, observational, cohort study. SETTING: A single-center, mixed medical/surgical, closed intensive care unit. PATIENTS:: Adults admitted to St. John's Mercy Medical Center between August 2001 and June 2003 (n = 2,085) were enrolled using Project Impact software. Both nonoperative and postoperative populations were represented, and transfusion decisions were made independently of patient study inclusion. Patients whose nosocomial infection was diagnosed before transfusion were counted as nontransfused. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS: Nosocomial infections, mortality rates, and intensive care unit and hospital length of stay were the main outcome measures. Of the 2,085 patients enrolled, 21.5% received red blood cell transfusions. The posttransfusion nosocomial infection rate was 14.3% in 428 evaluable patients, significantly higher than that observed in nontransfused patients (5.8%; p < .0001, chi-square). In a multivariate analysis controlling for patient age, maximum storage age of red blood cells, and number of red blood cell transfusions, only the number of transfusions was independently associated with nosocomial infection (odds ratio 1.097; 95% confidence interval 1.028-1.171; p = .005). When corrected for survival probability, the risk of nosocomial infection associated with red blood cell transfusions remained statistically significant (p < .0001). Leukoreduction tended to reduce the nosocomial infection rate but not significantly. Mortality and length of stay (intensive care unit and hospital) were significantly higher in transfused patients, even when corrected for illness severity. CONCLUSIONS: Red blood cell transfusions should be used sparingly, bearing in mind the potential risks of infection and poor outcomes in critically ill patients.     

Impairment of polymorphonuclear neutrophil functions precedes nosocomial infections in critically ill patients

OBJECTIVE: A postinjury immunodepression involving neutrophil functions has been described in critically ill patients. The aim of this prospective study was to search for a relationship between an impairment of neutrophil functions and the subsequent development of nosocomial infection. DESIGN: Twenty-one severely ill (simplified acute physiology score II >20 on admission), nonimmunosuppressed patients who were receiving no antibiotics active against methicillin-resistant Staphylococcus aureus and highly resistant Pseudomonas aeruginosa were included. Twelve healthy subjects constituted a control group. MEASUREMENTS: Neutrophil functions (phagocytosis and bactericidal activity toward S. aureus and P. aeruginosa in homologous plasma, reactive oxygen species secretion) were studied at day 4 +/- 1 after admission, and occurrence of nosocomial infection was prospectively recorded over the following 5 days. Interleukin-10 concentration was assessed by enzyme-linked immunosorbent assay. Results are expressed as median (25th-75th percentiles). MAIN RESULTS: Six out of the 21 patients acquired a nosocomial infection during the 5 days after blood sampling (infected group). Compared with the patients who did not acquire nosocomial infection (noninfected group, n = 15), the neutrophils of the infected group demonstrated a higher percentage of intracellular bacterial survival (17% [2% to 67%] vs. infected: 62% [22% to 100%], p <.05), leading to an impairment of S. aureus killing in homologous plasma (killed bacteria: 4.93 log(10) colony forming units/mL [4.24-5.29] vs. infected: 3.62 log(10) colony forming units/mL [0.00-4.58], p <.05). Interleukin-10 plasma concentration was higher in infected patients (78 pg/mL [60-83]) compared with noninfected patients (22 pg/mL [14-58], p <.05). By contrast, P. aeruginosa killing was similar in patients whether or not they acquired a nosocomial infection. CONCLUSION: A decrease in S. aureus killing capabilities of neutrophils can be evidenced within the days before occurrence of a nosocomial infection.     

Effects of dental plaque antiseptic decontamination on bacterial colonization and nosocomial infections in critically ill patients

OBJECTIVES: To document in intensive care unit (ICU) patients the effect of dental plaque antiseptic decontamination on the occurrence of plaque colonization by aerobic nosocomial pathogens and nosocomial infections. DESIGN: Single-blind randomized comparative study. SETTING: A 16-bed adult intensive care unit in a university hospital. PATIENTS: Patients consecutively admitted in the ICU with a medical condition suggesting an ICU stay of 5 days and requiring mechanical ventilation. INTERVENTIONS: After randomization, the treated group received dental plaque decontamination with 0.2% chlorhexidine gel, three times a day during the ICU stay. The control group received standard oral care. SPECIFIC MEASUREMENTS: Dental status was assessed by the Caries-Absent-Occluded index; the amount of dental plaque was assessed by a semi-quantitative plaque index. Bacterial sampling of dental plaque, nasal and tracheal aspirate, blood, and urine cultures were done on days 0, 5, 10, and every week. MAIN RESULTS: Sixty patients were included; 30 in the treated group and 30 in the control one (mean age: 51 +/- 16 years; mean Simplified Acute Physiological Score II: 35 +/- 14 points). On admission, no significant differences were found between both groups for all clinical and dental data. Compared with the control group, the nosocomial infection rate and the incidence densities related to risk exposition were significantly lower in the treated group (18 vs 33% days in the ICU and 10.7 vs 32.3% days of mechanical ventilation; P < 0.05). These results were consistent with a significant preventive effect of the antiseptic decontamination (Odds Ratio: 0.27; 95% CI: 0.09; 0.80) with a 53% relative risk reduction. There was a trend to a reduction of mortality, length of stay, and duration of mechanical ventilation. CONCLUSIONS: An antiseptic decontamination of dental plaque with a 0.2% chlorhexidine gel decreases dental bacterial colonization, and may reduce the incidence of nosocomial infections in ICU patients submitted to mechanical ventilation.     

Impact of lung ultrasound on clinical decision making in critically ill patients

Purpose

To assess the impact of lung ultrasound (LU) on clinical decision making in mechanically ventilated critically ill patients.

Methods

One hundred and eighty-nine patients took part in this prospective study. The patients were enrolled in the study when LU was requested by the primary physician for (1) unexplained deterioration of arterial blood gases and (2) a suspected pathologic entity [pneumothorax, significant pleural effusion (including parapneumonic effusion, empyema, or hemothorax), unilateral atelectasis (lobar or total), pneumonia and diffuse interstitial syndrome (pulmonary edema)].

Results

Two hundred and fifty-three LU examinations were performed; 108 studies (42.7 %) were performed for unexplained deterioration of arterial blood gases, and 145 (57.3 %) for a suspected pathologic entity (60 for pneumothorax, 34 for significant pleural effusion, 22 for diffuse interstitial syndrome, 15 for unilateral lobar or total lung atelectasis, and 14 for pneumonia). The net reclassification index was 85.6 %, indicating that LU significantly influenced the decision-making process. The management was changed directly as a result of information provided by the LU in 119 out of 253 cases (47 %). In 81 cases, the change in patient management involved invasive interventions (chest tube, bronchoscopy, diagnostic thoracentesis/fluid drainage, continuous venous–venous hemofiltration, abdominal decompression, tracheotomy), and in 38 cases, non-invasive (PEEP change/titration, recruitment maneuver, diuretics, physiotherapy, change in bed position, antibiotics initiation/change). In 53 out of 253 cases (21 %), LU revealed findings which supported diagnoses not suspected by the primary physician (7 cases of pneumothorax, 9 of significant pleural effusion, 9 of pneumonia, 16 of unilateral atelectasis, and 12 of diffuse interstitial syndrome).

Conclusion

Our study shows that LU has a significant impact on decision making and therapeutic management.     

Impact of anemia on outcome in critically ill patients with severe acute renal failure

Objective To evaluate the prognostic value of hemoglobin levels in critically ill patients with acute renal failure (ARF) requiring dialysis.Design and setting A prospective observational cohort study in two adult medical ICUs.Patients 206 consecutive patients with ARF who required dialysis. Overall 28-day mortality was 48%.Measurements and results At ICU admission mean hemoglobin level was 9.1±2.1 g/dl. By ROC curve analysis the threshold value of hemoglobin with the highest sensibility/specificity was 9 g/dl. At baseline 63% of patients had anemia, defined as initial hemoglobin below 9 g/dl. Kaplan-Meier analysis showed that these patients had lower survival rate than those with hemoglobin above 9 g/dl. By multivariable analysis three factors were independently associated with 28-day death: hemoglobin lower than 9 g/dl (adjusted odds ratio 2.4, 95% CI 1.1–5.2), age, and SOFA score. Based on age and SOFA a matched cohort analysis of 67 pairs of ARF patients with or without anemia found similar results regarding the negative impact of anemia on outcome. Finally, a multivariable logistic regression analysis on matched cohort identified hemoglobin level below 9 g/dl (adjusted odds ratio 1.32, 95%CI 1.15–1.46), continuous renal replacement therapy, and vasoactive therapy as independent predictors of 28-day death.Conclusions These results suggest that initial hemoglobin level could be helpful in identifying patients with ARF requiring dialysis at high risk of death.This article refers to the editorial     

Impact of early ICU admission on outcome of critically ill and critically ill cancer patients: A systematic review and meta-analysis.

ObjectivePrognostic impact of early ICU admission remains controversial. The aim of this review was to investigate the impact of early ICU admission in the general ICU population and in critically ill cancer patients and to report level of evidences of this later.MethodsSystematic review and meta-analysis performed on articles published between 1970 and 2017. Two authors extracted data. Influence of early ICU admission on mortality is reported as Risk Ratio (95%CI) using both fixed and random-effects model.Data synthesisFor general ICU population, 31 studies reporting on 73,213 patients were included (including 66,797 patients with early ICU admission) and for critically ill cancer patients 14 studies reporting on 2414 patients (including 1272 with early ICU admission) were included.Early ICU admission was associated with decreased mortality using a random effect model (RR 0.65; 95% confidence interval 0.58–0.73; I² = 66%) in overall ICU population as in critically ill cancer patients (RR 0.69; 95% confidence interval 0.52–0.90; I² = 85%).To explore heterogeneity, a meta-regression was performed. Characteristics of the trials (prospective vs. retrospective, monocenter vs. multicenter) had no impact on findings. Publication after 2010 (median publication period) was associated with a lower effect of early ICU admission (estimate 0.37; 95%CI 0.14–0.60; P = 0.002) in the general ICU population. A significant publication bias was observed.ConclusionTheses results suggest that early ICU admission is associated with decreased mortality in the general ICU population and in CICP. These results were however obtained from high risk of bias studies and a high heterogeneity was noted.Systematic review registration: PROSPERO 2018 CRD42018094828.     

Risk factors for nosocomial pneumonia in critically ill trauma patients

OBJECTIVE: To determine risk factors for nosocomial pneumonia in critically ill trauma patients. DESIGN: Prospective cohort study. SETTING: The trauma intensive care unit (ICU) of a 1500-bed tertiary-care hospital. PATIENTS: All critically ill trauma patients (n = 103) admitted consecutively between November 1995 and October 1996. INTERVENTIONS: A comparison of data recorded at the time of ICU admission and during the clinical evolution in patients with (n = 23) and without (n = 80) nosocomial pneumonia was made. Data referred mainly to possible risk factors were recorded; they also included factors related to pneumonia etiology and evolutive factors. Predictors of nosocomial pneumonia were assessed by logistic regression analysis. MEASUREMENTS AND MAIN RESULTS: The presence of significant growth on quantitative cultures of the protected specimen brush (> or = 103 colony forming units/mL) was required to accept pneumonia as microbiologically proven, as well as the concurrence of a cohort of clinical and radiologic signs. Twenty-three (22.3%) patients developed nosocomial pneumonia. The mean age of these patients was 41.7 yrs; 18 of them (78.3%) were men. The microorganisms isolated in significant concentrations were Acinetobacter baumanii (ten cases), Staphylococcus aureus (11 cases), Pseudomonas aeruginosa (five cases), Haemophilus influenzae (two cases), and Klebsiella pneumoniae, Citrobacter freundii, Serratia marcescens, Enterococcus spp., Enterobacter spp., coagulase-negative Staphylococcus, and Streptococcus intermedius (one case each one). Risk factors for pneumonia by univariate analysis included nasogastric tube; continuous enteral feeding; prolonged mechanical ventilation (>1 day); use of H2-receptor antagonist, sucralfate, muscle relaxants, corticosteroids, barbiturates, and inotropic agents; positive end-expiratory pressure; intense sedation; re-intubation; tracheotomy; urgent brain computed tomography (CT) scan; craniotomy; iatrogenic event; and hyperventilation. The mortality rate was 43.5% (10 of 23) in the nosocomial pneumonia group and 18.8% in patients without nosocomial pneumonia (p =.02). Also, the mean stay in the ICU, the therapeutic charge (measured with total and mean punctuation of the Therapeutic Intervention Scoring System) and the complications, infectious and noninfectious, of the clinical evolution were significantly more frequent in patients with nosocomial pneumonia than in those without pneumonia (p <.05). In the multivariate analysis, continuous enteral feeding, craniotomy, prolonged mechanical ventilation (>24 hrs), use of positive end-expiratory pressure, and corticotherapy were independent predictors of nosocomial pneumonia. CONCLUSIONS: It seems that factors related to the patient's clinical course, rather than variables registered on the first days of ICU admission, are those that would exert an influence on the development of nosocomial pneumonia in critically ill trauma patients. In this way, from our point of view, in our study the main risk factors are the use of prolonged mechanical ventilation (>4 hrs) and positive end-expiratory pressure. At the same time, we can conclude that the reduction of this infection incidence could decrease the mean stay in the ICU, the therapeutic charge, and the prognosis in terms of mortality and morbidity.     

Risk factors for nosocomial pneumonia in critically ill trauma patients

Nosocomial pneumonia is the most common pulmonary complication in trauma patients and the leading cause of death in nosocomial infections. A comprehensive review of pneumonia studies is provided. The Centers for Disease Control's nosocomial pneumonia pathogenesis model is reviewed and was used to guide the selection of risk factors evaluated in this study. The purposes of this research were to identify underlying dimensions (factors) of variables that increase the risk of nosocomial pneumonia and to identify predictors of nosocomial pneumonia in critically ill trauma patients.     

Old antibiotics for infections in critically ill patients

PURPOSE OF REVIEW: The alarming epidemic of multidrug-resistant bacteria and the reluctance of the pharmaceutical industry to invest in the development of new antibiotics have forced clinicians to reintroduce forgotten antibiotics into their practice. This review highlights the effectiveness and safety of older antibiotics when used in the treatment of infections of critically ill patients. RECENT FINDINGS: Polymyxins emerged as useful antibiotics for the treatment of infections due to multidrug-resistant Gram-negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae. The nephrotoxicity and neurotoxicity associated with their use are less frequent and serious than previously reported. In addition, aerosolized polymyxins may be a useful weapon in the treatment of hospital-acquired pneumonia. Fosfomycin and chloramphenicol have a wide antimicrobial spectrum, are used extensively in Europe and Africa, respectively, and may have an expanded role in our antimicrobial arsenal. Fusidic acid remains active against various staphylococcal strains, while isepamicin (an aminoglycoside used in some European countries) is slightly more effective than amikacin against some Gram-negative bacteria. SUMMARY: The declining investment of the pharmaceutical industry in the development of new antibiotics and the increasing antimicrobial resistance create a fertile ground for the study and, probably, revival of older antibiotics for use, especially in critically ill patients.     

Human cytomegalovirus infections in nonimmunosuppressed critically ill patients

OBJECTIVE: To assess the occurrence of active human cytomegalovirus (HCMV) infection and HCMV disease and to evaluate potential risk factors in immunocompetent intensive care patients after major surgery or trauma. DESIGN: A prospective clinical study. SETTING: An anesthesiological intensive care unit (ICU) in a university hospital. PATIENTS: Fifty-six anti-HCMV immunoglobulin G (IgG) seropositive patients without manifest immunodeficiency whose simplified acute physiology score (SAPS II) value rose to >or=41 points during their ICU stay. INTERVENTIONS: Once a week, the patients were examined for active HCMV infection by polymerase chain reaction and by viral cultures from blood and lower respiratory tract secretions. Three times a week, detailed clinical examination for signs of HCMV disease was carried out. MEASUREMENTS AND MAIN RESULTS: Twenty of the 56 ICU patients (35.6%) who met the study criteria of a SAPS II score >40 points and anti-HCMV IgG seropositivity developed an active HCMV infection as diagnosed by the detection of HCMV DNA in leukocytes, plasma, or respiratory tract secretions. In seven patients, the virus was isolated in the respiratory tract secretions. Severe HCMV disease appeared in two patients with pneumonia or encephalitis respectively. In patients with active HCMV infection, the mortality tended to be higher (55%) than in those without (36%); the duration of intensive care treatment of the survivors was significantly longer in the patients with active HCMV infection (median 30 vs. 23 days; p = .0375). Univariate testing for factors associated with active HCMV infection showed the importance of sepsis at admission (p = .011) and prolonged pretreatment on the ward or in an external ICU (p = .002); the relevance of underlying malignant disease was borderline (p = .059). Multiple regression analysis identified only sepsis to be independently associated with active HCMV infection (p = .02; odds ratio, 4.62). CONCLUSIONS: Even in a group of ICU patients without manifest immunodeficit who were anti-HCMV IgG seropositive and had reached a SAPS II score of >or=41 points, active HCMV infection occurred frequently (35.6%). Septic patients were affected twice as often as the total study population. In 2 of the 20 cases, active HCMV infection progressed to severe HCMV disease. Proper diagnosis demands special clinical attention combined with extended virological examinations. Further studies in a larger patient group should evaluate the influence of HCMV on ICU mortality.     

Impact of colony-stimulating factor therapy on clinical outcome and frequency rate of nosocomial infections in intensive care unit neutropenic patients

OBJECTIVES: To determine whether the use of recombinant human granulocyte colony-stimulating factor (G-CSF, filgrastim) reduces the mortality rate and the frequency rate of nosocomial infections in neutropenic patients requiring intensive care unit (ICU) admission. DESIGN: Retrospective consecutive case series analysis. SETTING: Medical ICU of a teaching hospital. PATIENTS: We compared two groups of patients, according to whether or not they received G-CSF. In the ICU, 28 leukopenic patients received filgrastim (5 microg of body weight per day intravenously). In all these patients, G-CSF was continued until recovery from leukopenia, defined as a leukocyte count >1,000/mm3. A total of 33 ICU leukopenic patients did not receive G-CSF. End points included leukocyte count, bone marrow recovery, frequency of ICU nosocomial infections (pneumonia, urinary tract, and catheter-related infections), and mortality rate. MEASUREMENTS AND MAIN RESULTS: There were no differences in number of patients who recovered from leukopenia or in whom blood leukocyte count increased. Nosocomial infections occurred in the same percentage in both groups. The percentage of patients who died was identical in both groups. The percentage of patients with and without filgrastim therapy who recovered from leukopenia but died, was 86% and 78%, respectively. CONCLUSION: In the ICU, clinical outcome of neutropenic patients was not changed by G-CSF therapy. It is possible that G-CSF therapy may not be helpful in improving the ICU clinical outcome of neutropenic patients. Additional controlled studies designed to address this question are warranted.     

Assessing illness severity and outcome in critically ill patients

Severity of illness scores have great potential to improve use of scarce resources and to help monitor quality of care. Injury severity scores can reliably separate trauma patients into high- and low-mortality groups, but have limitations when applied in triage decision making. Specific predictive models for chest pain patients have improved admitting practices in some emergency departments. Univariate predictors of survival include age, severity of illness, and presence of chronic illnesses, especially cancer. General multivariate models for intensive care patients have correctly categorized hospital outcome in approximately 85 per cent of cases when applied in a retrospective fashion. These models are insufficiently precise for application to individual patients; but they may be helpful in assessing quality of care in the intensive care unit, in assessing efficacy of new technologies, and in utilization review audits.     

Arterial carboxyhemoglobin level and outcome in critically ill patients

OBJECTIVE: Arterial carboxyhemoglobin is elevated in patients with critical illness. It is an indicator of the endogenous production of carbon monoxide by the enzyme heme oxygenase, which modulates the response to oxidant stress. The objective was to explore the hypothesis that arterial carboxyhemoglobin level is associated with inflammation and survival in patients requiring cardiothoracic intensive care. DESIGN: Prospective, observational study. SETTING: A cardiothoracic intensive care unit. PATIENTS: All patients admitted over a 15-month period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Arterial carboxyhemoglobin, bilirubin, and standard biochemical, hematologic, and physiologic markers of inflammation were measured in 1,267 patients. Associations were sought between levels of arterial carboxyhemoglobin, markers of the inflammatory response, and clinical outcome. Intensive care unit mortality was associated with lower minimum and greater maximal carboxyhemoglobin levels (p < .0001 and p < .001, respectively). After adjustment for age, gender, illness severity, and other relevant variables, a lower minimum arterial carboxyhemoglobin was associated with an increased risk of death from all causes (odds risk of death, 0.391; 95% confidence interval, 0.190-0.807; p = .011). Arterial carboxyhemoglobin correlated with markers of the inflammatory response. CONCLUSIONS: Both low minimum and high maximum levels of arterial carboxyhemoglobin were associated with increased intensive care mortality. Although the heme oxygenase system is protective, excessive induction may be deleterious. This suggests that there may be an optimal range for heme oxygenase-1 induction.     

Use of the injury severity score to predict nosocomial bloodstream infections among critically ill trauma patients

Nosocomial bloodstream infections (NBSI) are associated with increased hospital length of stay (LOS), mortality, and costs. At this writing, no available reports describe the association between injury severity and NBSI among critically ill adult trauma patients. This study aimed to examine the use of the Injury Severity Score (ISS) as a predictor of NBSI among critically ill adult trauma patients. A case-control design was used to compare the mean ISS of 190 critically ill trauma patients equally divided between those with positive test results for NBSI and those with negative results. The mean hospital LOS (34.8 days versus 16.5 days) and the mean intensive care unit LOS (28.1 days versus 13 days) were significantly higher among the patients with NBSI than among the control subjects without such infection (P <.001 and P <.001, respectively). The mean LOS until the diagnosis of NBSI was significantly lower than the total LOS of the control subjects (odds ratio [OR], 0.959; 95% confidence interval [CI], 0.93-0.99). The ISS score and age were found to be independent predictors of NBSI. The findings provide a means for using the ISS score as a predictor of NBSI in the critically ill adult trauma population.     

Impact of sterile leukocyturia on outcome of critically ill patients with severe acute kidney injury

IntroductionThe role of immunological mechanisms on renal regeneration and functional recovery after an episode of Acute Kidney Injury (AKI) is still understudied. We aim to evaluate the impact of sterile leukocyturia on outcomes of critically-ill AKI patients.MethodsA retrospective analysis of critically-ill patients with stage ≥2 AKI by KDIGO was performed. Patients with urinary tract infection, previous renal replacement therapy, chronic kidney disease stage >3 and kidney, urinary tract or prostatic cancer were excluded. Sterile leukocyturia was defined as a positive leukocyte esterase value.Results108 patients with stage ≥2 AKI were included, 39.8% of which had sterile leukocyturia. AKI patients with sterile leukocyturia were older, had more cardiovascular disease and a lower baseline renal function (p < 0.05). They had a higher serum creatinine and leukocytosis at admission, were more frequently septic (p < 0.05) and had more persistent AKI by both KDIGO criteria at multivariable analysis (OR 6.130, 95% CI 2.007–18.747).ConclusionSterile leukocyturia was associated with different patient baseline and AKI characteristics and more persistent AKI by both KDIGO criteria. Sterile leukocyturia may represent a surrogate marker of renal inflammation during AKI.