Importance, morbidity, and mortality of pneumonia in the surgical intensive care unit

(1→3)-β-D-Glucan reduces the damages caused by reactive oxygen species induced in human platelets by lipopolysaccharides

LPS (lipopolysaccharide) induces platelet activation and is a well-known fundamental agent of septic shock and disseminated intravascular coagulation (DIC). Biological activity of (1→3)-β-D-glucan is related due to its anti-inflammatory, antioxidant, and antitumor properties. We focus our attention on the (1→3)-β-D-glucan (antiplatelet) properties. The main purpose of our study was to evaluate the influence of (1→3)-β-D-glucan from Saccharomyces cerevisiae on destructive activity of LPS (from Escherichia coli and Pseudomonas aeruginosa) on human blood platelets. We assess biochemically in vitro if (1→3)-β-D-glucan might combat the oxidative stress caused by LPS stroke associated with nitrative and oxidative damages of human platelet biomolecules. We also make an attempt by in silico molecular docking to determine the interactions between the molecules of (1→3)-β-D-glucan and LPS. Our conclusion is that protective mechanism of (1→3)-β-D-glucan against LPS action on blood platelets is due to as well: its antioxidant properties, as to its interaction with LPS-binding region of TLR4-MD-2 complex.

Efficacy of therapy with recombinant human activated protein C of critically ill surgical patients with infection complicated by septic shock and multiple organ dysfunction syndrome

BACKGROUND

Septic shock causing or complicating critical surgical illness results in high mortality. Drotrecogin alfa (activated), known also as recombinant human activated protein C (rhAPC) has become controversial as therapy, owing to persisting questions of efficacy and safety. We hypothesized rhAPC to be effective therapy for critically ill surgical patients with septic shock.

METHODS

Open-label therapy with rhAPC (by predefined criteria) of 108 critically ill surgical patients. Treated patients were matched individually in prospect for age, gender, Acute Physiology and Chronic Health Evaluation (APACHE)-II and -III scores, site of infection, and organism (0-2 points each, maximum 12 points) with 108 patients from our 15,000-patient surgical intensive care unit database who did not receive rhAPC. No match was accepted if <6 points. Multiple organ dysfunction (MOD) scores and data regarding cortisol concentrations, bleeding complications, and transfusion requirements were collected. The primary endpoint was 28-day mortality, with mortality for hospitalization and resolution of organ dysfunction as secondary endpoints. Statistical analyses included ANOVA, c statistic, binary logistic regression, and Kaplan-Meier time-to-event and Cox proportional hazards analyses; α=0.05.

RESULTS

The mean match score was 9.2±0.1 points (range, 6-12 points). Patients were well matched by all criteria, including baseline MOD score (9.5±0.7 vs. 9.8±0.3 points, p=0.66). Mean age was 68.1±1.1 years (p=0.49), Mean APACHE-III score was 99.6±1.5 points (p=0.87). Mean time to rhAPC administration was 25±3 h. Survival at 28 days after rhAPC was 71.3% vs. 49.1% (p=0.001); hospital survival was 57.4% vs. 40.7% (p=0.02). By logistic regression, rhAPC therapy resulted in improved 28-day survival (OR 2.57, 95% CI 1.46-4.52, p=0.001) (model χ2 11.244, p=0.001); and hospital survival (OR 1.96, 95% CI 1.14-3.36, p=0.015) (model χ2 6.03, p=0.014). The MOD score decreased significantly (p=0.012) during rhAPC therapy.

CONCLUSION

Therapy with rhAPC appeared to improve survival in surgical ICU patients with life-threatening infection characterized by septic shock and organ dysfunction.

The pathogen of ventilator-associated pneumonia does not influence the mortality rate of surgical intensive care unit patients treated with a rotational antibiotic system

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the leading causes of morbidity in critically ill surgical patients. Certain pathogens (e.g., methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa) have been associated with an excess mortality rate from sepsis in several studies, but not in the surgical setting specifically or when protocol-driven antibiotic therapy is administered.

PURPOSE

We sought to determine which factors and, in particular, whether the individual pathogen affected the mortality rate in our surgical intensive care unit (ICU), where a rotational antibiotic system has been employed continuously since 1997. We hypothesized that the type of pathogen and illness severity were the primary influences on the mortality rate of patients with VAP.

METHODS

A total of 198 consecutive patients from a university surgical ICU, with clinical signs of VAP confirmed by quantified isolation of significant numbers of a pathogen (> or =10(4) colony-forming units [cfu]/mL) from bronchoalveolar (BAL) fluid obtained by fiberoptic bronchoscopy, were identified prospectively from January 2001 to November 2004. The data collected were age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) III score, multiple organ dysfunction score, unit day of diagnosis, time (h) to antibiotic administration (TTA), appropriateness of initial therapy (AIT), unit and hospital length of stay, and mortality rate. Pathogens were classified as non-lactose-fermenting gram-negative bacilli (NGNB), lactose-fermenting gram-negative bacilli (LGNB), methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, yeast, community-acquired pneumonia (e.g., Streptococcus pneumoniae), or other pathogens. Patients with a polymicrobial isolate were placed in the "other" category.

RESULTS

The overall mortality rate was 32.3% vs. 55% as predicted by APACHE III normative data. The overall AIT was 92%. The mortality rate for NGNB infections was 35.6% vs. 29.4% for LGNB infections (p = NS). By logistic regression, neither TTA, AIT, nor pathogen influenced the mortality rate.

CONCLUSIONS

The type of pathogen does not influence death in surgical ICU patients with VAP diagnosed rigorously and treated by a rotational antibiotic system. The high proportion of AIT as a result of the rotational antibiotic administration system optimizes bacterial killing and negates the impact of bacterial resistance, contributing to better outcomes.

Trauma sepsis

Sepsis is a major cause of mortality and morbidity in the trauma patient. Sepsis following traumatic injury is related to the type of injury, together with the extent of injury and the anatomical location. Burn injuries are associated with the highest risk of sepsis. The diagnosis of sepsis in the trauma patient remains difficult. Interpretation of abnormal results is key to successful diagnosis, particularly in conjunction with clinical findings. This review will consider the specific features of sepsis in the context of trauma relating to epidemiology, risk factors, diagnosis and management.

Pseudomonas aeruginosa induces interleukin-8 (IL-8) gene expression in human conjunctiva through the recruitment of both RelA and CCAAT/enhancer-binding protein beta to the IL-8 promoter

The purpose of this study was to identify the Pseudomonas aeruginosa-activated signaling pathway leading to interleukin (IL)-8 gene expression and protein synthesis by human conjunctival epithelium. IL-8 protein and mRNA were determined by enzyme-linked immunosorbent assay and reverse transcription-PCR, respectively. Activation of MAPKs and NF-kappaB was analyzed by Western blotting using phosphospecific antibodies. We used transfection with wild-type or mutated IL-8 promoters and cotransfection with transcription factor overexpressing plasmids or small interfering RNAs. Electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) were performed for in vitro and in vivo protein-DNA binding studies, respectively. P. aeruginosa increased IL-8 expression at the transcriptional level by phosphorylating CCAAT/enhancer-binding protein beta (C/EBPbeta) via p38MAPK and activating NF-kappaB. The simultaneous involvement of RelA and C/EBPbeta and the integrity of the corresponding consensus sites were required, whereas c-Jun was involved only in basal IL-8 expression. Re-ChIP experiments showed that RelA and C/EBPbeta act together at the IL-8 promoter level upon P. aeruginosa infection. Taken together, our results suggest that P. aeruginosa induces IL-8 promoter expression and protein production in conjunctival epithelial cells by activating RelA and C/EBPbeta and by promoting the cooperative binding of these transcription factors to the IL-8 promoter that in turn activates transcription.

Article Commentary: Strategies in the Prevention and Management of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in the intensive care unit. Prevention of VAP is possible through the use of several evidence-based strategies intended to minimize intubation, the duration of mechanical ventilation, and the risk of aspiration of oropharyngeal pathogens. Current data favor the quantitative analysis of lower respiratory tract cultures for the diagnosis of VAP, accompanied by the initiation of broad-spectrum empiric antimicrobial therapy based on patient risk factors for infection with multi-drug-resistant pathogens and data from unit-specific antibiograms. Eventual choice of antibiotic and duration of therapy are selected based on culture results and patient stability, with an emphasis on minimization of unnecessary antibiotic use.

Antibiotic prophylaxis in clean-contaminated head and neck oncological surgery

BACKGROUND

Perioperative antibiotic prophylaxis has significantly reduced wound infection rates in clean-contaminated head and neck surgical procedures but controversy still remains regarding the optimal antibiotic regime.

OBJECTIVE

To examine the efficacy of different antibiotics in head and neck oncological surgery prophylaxis.

PATIENTS AND METHODS

In this prospective, double-blind clinical trial, 189 patients with carcinoma of the upper aerodigestive tract were randomized to receive amoxicillin-clavulanate or cefazolin intravenously up to 1h before surgery and at 8-h intervals for an additional three doses.

RESULTS

An overall wound infection rate of 22% was observed. The infection rate in patients receiving cefazolin was 24% (22/92) vs. 21% (20/97) in those receiving amoxicillin-clavulanate; the difference was not statistically significant. Postoperative overall non-wound infection developed in 12% (22/189) patients; the rate of infection was 9.8% (9/92) in patients receiving cefazolin vs. 13.4% (13/97) in those receiving amoxicillin-clavulanate, without a statistically significant difference between the two groups. Gram-negative bacteria were more often isolated with Pseudomonas aeruginosa as the dominant species. The risk of postoperative infection was more influenced by the type of surgical procedure than by disease stage.

CONCLUSION

In clean-contaminated head and neck oncologic surgery amoxicillin-clavulanate prophylaxis was at least as efficient as cefazolin. However, when taking into account the fact that beta-lactamase containing strains have recently been spreading, amoxicillin-clavulanate should be the logical first choice.

Can the clinical pulmonary infection score impact ICU antibiotic days?

BACKGROUND

The Clinical Pulmonary Infection Score (CPIS) has been used in the intensive care unit (ICU) as a decision tool for initiation of antibiotics in suspected pneumonia and also for discontinuing antibiotics if the CPIS score is <or=6 on day three of therapy, but it is not in common clinical use. We sought to determine if application of a CPIS score<or=6 at three days could reduce antibiotic use and if a blinded committee would have a greater percentage of patients with CPIS>6 on day one receiving antibiotics empirically for pneumonia.

METHODS

Over 11 months, we evaluated empiric antibiotics prospectively in two ICUs of a large tertiary university teaching hospital. A pneumonia committee (PC) reviewed all patients and defined pneumonia according to the guidelines of the U.S. Centers for Disease Control and Prevention (CDC). The CPIS was calculated for all patients at day one and day three of antibiotic therapy. The percentage of patients with a CPIS<or=6 was compared for the ICU and PC, and the total antibiotic days potentially saved by using CPIS<or=6 as the criterion for treatment were determined. Receiver operating characteristic (ROC) curves and inter-observer reliability were determined.

RESULTS

Three hundred twelve patients received empiric antibiotics, 83 of whom were believed to have pneumonia by the ICU staff (2,283 antibiotic days). On day one, the 55 patients started on antibiotics had a CPIS<or=6, with 1,460 antibiotic-days, and only 28 patients had a CPIS>6 (823 antibiotic-days). In contrast, the PC determined 19 patients (23%) to have pneumonia by the CDC definition (731 antibiotic-days), with eight of these patients having a CPIS<or=6 and 11 a CPIS>6. Pneumonia committee review resulted in fewer patients believed to have pneumonia and a greater percentage with a CPIS>6 (odds ratio [OR] 2.7; 95% confidence interval [CI] 0.86, 8.6; p=0.05). Restriction of antibiotics to patients with a CPIS>6 would have saved 1,460 antibiotic-days at day one and 1,053 days if treatment was delayed until day three. Clinical Pulmonary Infection Score ROC curves for the PC showed an area under the curve (AUC) of 0.82 (95% CI 0.72, 0.91), whereas the AUC for the ICU group was 0.85 (95% CI 0.79, 0.92). The sensitivity and specificity of a CPIS>6 for the PC were 79% and 75%, respectively, with correct prediction 76% of the time. The inter-observer reliability of the CPIS had a kappa value of 0.88.

CONCLUSIONS

This prospective evaluation confirms that 50% of antibiotic-days in our ICU are used empirically for pneumonia when that infection is not likely to be present by either CDC or CPIS criteria. Although the CPIS has good reliability and acceptable sensitivity and specificity, PC review and CPIS<or=6 were commonly divergent (42-47%). Thus, better strategies should be developed for identification of pneumonia and empiric antibiotic administration in the ICU.

National nosocomial infection surveillance system: from benchmark to bedside in trauma patients

INTRODUCTION

Ventilator-associated pneumonia (VAP) is an important cause of morbidity and mortality in the injured patient. Identification of those with VAP is important both in immediate clinical decision making as well as for the epidemiologic evaluation of the disease and benchmarking of rates across institutions with variable practice patterns. Despite this, controversy exists over the optimal method of VAP diagnosis. Many centers currently use invasive culture methods such as bronchoalveolar lavage (BAL) for diagnosis. Another diagnostic method, and the most common epidemiologic tool used to track VAP, is the definition employed by the National Nosocomial Infections Surveillance (NNIS) system. This relies on a combination of clinical and culture data. Our goal was to evaluate the accuracy of the NNIS definition as compared with BAL diagnosis in trauma patients.

METHODS

Records of all ventilated patients admitted to the trauma intensive care unit at a Level I center who were evaluated for the presence of pneumonia over a 2.5-year period were reviewed. VAP diagnosis was established if > or =10 cfu/mL were cultured on BAL. VAP rates and time of onset were compared with the hospital infection control database, which defines VAP by NNIS criteria. Assuming BAL to be correct, sensitivity, specificity, and positive and negative predictive values were calculated for NNIS VAP.

RESULTS

From September 1, 2001, through December 31, 2003, 292 patients underwent BAL for suspected pneumonia. The pneumonia rate in this group was 34 per 1,000 ventilator days. The NNIS definition showed excellent overall agreement, with a rate of 36 per 1,000 ventilator days. The use of the NNIS definition for bedside decision making, however, is less accurate. Sensitivity and positive predictive value were reasonably good (84% and 83%, respectively), whereas specificity and negative predictive value suffer (69% and 69%, respectively). Most importantly, the use of NNIS would have led to no treatment in 16% of patients diagnosed with VAP by BAL.

CONCLUSIONS

Compared with strict bacteriologic criteria for VAP, the NNIS definition has good overall agreement and seems to have utility as an epidemiologic benchmarking tool in trauma patients. However, the NNIS definition has less utility as a bedside decision-making tool in this population, leading to under-treatment in a significant number of patients.

Réservoirs et transmission de Pseudomonas aeruginosa en réanimation médicale

OBJECTIVE

The authors had for aim to study reservoirs and transmission of Pseudomonas aeruginosa in an intensive care unit.

DESIGN

A 6-month prospective descriptive study was made on water samples, samples from hands of health care workers, and clinical samples. P. aeruginosa strains were compared by pulsed-field gel electrophoresis.

RESULTS

Among the 211 patients hospitalized during the study, 14 (6.6%) were infected by P. aeruginosa. Out of 494 water samples, 80 were contaminated by P. aeruginosa. The regularly disinfected water taps were more rarely contaminated than the others (P<10(-5)). Out of 140 hand samples, one showed contamination from an infected patient.

CONCLUSIONS

aeruginosa cross transmission was observed during this study. We should follow strict hygienic precautions such as wearing gloves and performing thorough alcoholic rub disinfection. Water taps are often contaminated and require regular disinfection.

Cervical spine injuries in the elderly: acute postoperative mortality

STUDY DESIGN

This study retrospectively reviewed 12 years of consecutive patients with cervical spine injuries.

OBJECTIVE

To establish reasonable expectations for short-term postoperative survival of the elderly patient with a cervical spine injury.

SUMMARY OF BACKGROUND DATA

Previous studies have outlined dismal expectations for patients older than 65 years, with cervical spine injuries. This result has led many surgeons to consider more conservative treatment when compared to younger patients with similar injuries.

METHODS

A total of 458 patients treated surgically over a 12-year period at a single tertiary spine care center were reviewed. The patients were divided into 2 groups by age, older and younger than 65 years. Prospective data were collected from the time of admission to discharge from the acute care facility, and included age, injury etiology, anatomic and neurologic injury patterns, and morbidity and mortality

RESULTS

There were 74 patients older than 65 years and 384 younger than 65 years who underwent surgical stabilization of their injury. The overall mortality rate during the initial hospitalization was 3.9%. The mortality rate of the elderly group was 12.2%, while 2.3% for the younger patients. Common postoperative morbidities in the older group included myocardial infarction, deep vein thrombosis, pulmonary emboli, and gastrointestinal bleeds. In the younger group, pneumonia, respiratory failure, and urinary tract infections were more frequent.

CONCLUSIONS

The realistic expectation for short-term postoperative survival in the elderly patient with a cervical spine injury is 87.8%. With a complete neurologic injury, 80.0% short-term survival was observed. Incomplete neurologic injury yielded 83.3% short-term survival. Close to 100.0% survival can be expected with no neurologic injury.

Preventing antimicrobial-resistant bacterial infections in surgical patients

BACKGROUND

The Centers for Disease Control and Prevention (CDC) has identified the control of antimicrobial resistance as an important effort to reduce the morbidity and mortality associated with health care. Methods to prevent these infections in surgical patients have rarely been addressed specifically.

METHODS

The peer-reviewed literature and published guidelines were examined to identify proven or suggested techniques for controlling antimicrobial resistance that would be particularly relevant to surgeons and the surgical patient population.

RESULTS

A multi-step approach to the prevention of antimicrobial-resistant infections in surgical patients was developed. This program consists of four major strategies: Infection prevention, effective diagnosis and treatment of infection, optimal antibiotic utilization, and the prevention of transmission.

CONCLUSION

The control of antimicrobial resistance in bacteria is an important objective for all physicians, including surgeons. An approach to attain this goal in surgical populations is outlined. Further research will be needed to determine the value of these practices and to develop newer, even more effective interventions.

A Multisite Survey of Suctioning Techniques and Airway Management Practices

• Background Ventilator-associated pneumonia, common in critically ill patients, is associated with microaspiration of oropharyngeal secretions and may be related to suctioning and airway management practices.

• Objectives To describe institutional policies and procedures related to closed-system suctioning and airway management of intubated patients, and to compare practices of registered nurses and respiratory therapists.

• Methods A descriptive, comparative, multisite study of facilities that use closed-system suctioning devices on most intubated adults was conducted. Nurses and respiratory therapists who worked at the sites completed surveys related to their practices.

• Results A total of 1665 nurses and respiratory therapists at 27 sites throughout the United States responded. The typical respondent had at least 6 years’ experience with patients receiving mechanical ventilation (61%) and a baccalaureate degree or higher (54%). Most sites had policies for management of endotracheal tube cuffs (93%), hyperoxygenation (89%) and use of gloves (70%) with closed-system suctioning, and instillation of isotonic sodium chloride solution for thick secretions (74%). Only 48% of policies addressed oral care and 37% addressed oral suctioning. Nurses did more oral suctioning and oral care than respiratory therapists did, and respiratory therapists instilled sodium chloride solution more and rinsed the suctioning device more often than nurses did.

• Conclusions Policies vary widely and do not always reflect current research. Consistent performance of practices such as wearing gloves for airway management and maintaining endotracheal cuff pressures must be evaluated. Collaborative, research-based policies and procedures must be developed and implemented to ensure best practices for intubated patients.

Bacterial Growth in Secretions and on Suctioning Equipment of Orally Intubated Patients: A Pilot Study

• Background Contamination of equipment, colonization of the oropharynx, and microaspiration of secretions are causative factors for ventilator-associated pneumonia. Suctioning and airway management practices may influence the development of ventilator-associated pneumonia.

• Objectives To identify pathogens associated with ventilator-associated pneumonia in oral and endotracheal aspirates and to evaluate bacterial growth on oral and endotracheal suctioning equipment.

• Methods Specimens were collected from 20 subjects who were orally intubated for at least 24 hours and required mechanical ventilation. At baseline, oral and sputum specimens were obtained for culturing, and suctioning equipment was changed. Specimens from the mouth, sputum, and equipment for culturing were obtained at 24 hours (n = 18) and 48 hours (n = 10).

• Results After 24 hours, all subjects had potential pathogens in the mouth, and 67% had sputum cultures positive for pathogens. Suctioning devices were colonized with many of the same pathogens that were present in the mouth. Nearly all (94%) of tonsil suction devices were colonized within 24 hours. Most potential pathogens were gram-positive bacteria. Gram-negative bacteria and antibiotic-resistant organisms were also present in several samples.

• Conclusions The presence of pathogens in oral and sputum specimens in most patients supports the notion that microaspiration of secretions occurs. Colonization is a risk factor for ventilator-associated pneumonia. The equipment used for oral and endotracheal suctioning becomes colonized with potential pathogens within 24 hours. It is not known if reusable oral suction equipment contributes to colonization; however, because many bacteria are exogenous to patients’ normal flora, equipment may be a source of cross-contamination.

Postoperative nosocomial pneumonia: nurse-sensitive interventions

Nosocomial pneumonia (NP) is well documented as the second most common nosocomial infection. It is now more common in surgical patients than surgical-site or wound infection. Healthcare implications of NP include not only increased patient morbidity and mortality, but also increased use of healthcare resources. The advanced practice nurse plays an integral role in the prevention and minimization of NP across healthcare settings. This article focuses on postoperative NP after abdominal, cardiac, or thoracic surgery in the non-mechanically ventilated patient and discusses the diagnostic assessment, risk factors, and potential nurse-sensitive interventions to prevent or minimize this complication. Ideas for potential nursing research related to these risk factors are described.