Antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving intensive care

Probiotics for preventing acute upper respiratory tract infections

BACKGROUND

Probiotics are live micro-organisms that may give a beneficial physiological effect when administered in adequate amounts. Some trials show that probiotic strains can prevent respiratory infections. Even though our previously published review showed the benefits of probiotics for acute upper respiratory tract infections (URTIs), several new studies have been published. This is an update of a review first published in 2011 and updated in 2015.

OBJECTIVES

To assess the effectiveness and safety of probiotics (any specified strain or dose), compared with placebo or no treatment, in the prevention of acute URTIs in people of all ages, at risk of acute URTIs.

SEARCH METHODS

We searched CENTRAL (2022, Issue 6), MEDLINE (1950 to May week 2, 2022), Embase (1974 to 10 May 2022), Web of Science (1900 to 10 May 2022), the Chinese Biomedical Literature Database, which includes the China Biological Medicine Database (from 1978 to 10 May 2022), the Chinese Medicine Popular Science Literature Database (from 2000 to 10 May 2022), and the Master's Degree Dissertation of Beijing Union Medical College Database (from 1981 to 10 May 2022). We searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov for completed and ongoing trials on 10 May 2022.

SELECTION CRITERIA

We included individual randomised controlled trials (RCTs) and cluster-RCTs comparing probiotics with placebo or no treatment to prevent acute URTIs. The participants were children, adults, or the elderly in the community, care facilities, schools, or hospitals. Our main outcomes were the number of participants diagnosed with URTIs (at least one event and at least three events), the incidence rate (number of cases/person year) of acute URTIs, and the mean duration of an episode of URTIs. Our secondary outcomes were the number of participants who were absent from childcare centre, school, or work due to acute URTIs; the number of participants who used prescribed antibiotics for acute URTIs; and the number of participants who experienced at least one adverse event from probiotics. We excluded studies if they did not specify acute respiratory infections as 'upper'; studies with more than 50% of participants vaccinated against influenza or other acute URTIs within the last 12 months; and studies with significantly different proportions of vaccinated participants between the probiotics arm and the placebo or no treatment arm.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of trials and extracted data using standard Cochrane methodological procedures. We analysed both intention-to-treat and per-protocol data and used a random-effects model. We expressed results as risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, both with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 23 individual RCTs and one cluster-RCT. As one of the individual RCTs did not report outcomes in a usable way, we could only meta-analyse data from 23 trials, involving a total of 6950 participants including children (aged from one month to 11 years old), adults (mean age 37.3), and older people (mean age 84.6 years). One trial reported 22.5% flu-vaccine participants within the last 12 months, and 25.4% flu-vaccine participants during the intervention. Probiotics were more likely to be given with milk-based food in children; administered in powder form in adults; and given with milk-based food or in capsules in the elderly. Most of the studies used one or two strains (e.g. Lactobacillus plantarum HEAL9, Lactobacillus paracasei (8700:2 or N1115)) and 109 or 1011 colony-forming units (CFU)/day of probiotics for more than three months. We found that probiotics may reduce the number of participants diagnosed with URTIs (at least one event) (RR 0.76, 95% CI 0.67 to 0.87; P < 0.001; 16 studies, 4798 participants; low-certainty evidence); likely reduce the number of participants diagnosed with URTIs (at least three events) (RR 0.59, 95% CI 0.38 to 0.91; P = 0.02; 4 studies, 763 participants; moderate-certainty evidence); may reduce the incidence rate (number of cases/person year) of URTIs (rate ratio 0.82, 95% CI 0.73 to 0.92, P = 0.001; 12 studies, 4364 participants; low-certainty evidence); may reduce the mean duration of an episode of acute URTIs (MD -1.22 days, 95% CI -2.12 to -0.33; P = 0.007; 6 studies, 2406 participants; low-certainty evidence); likely reduce the number of participants who used prescribed antibiotics for acute URTIs (RR 0.58, 95% CI 0.42 to 0.81; P = 0.001; 6 studies, 1548 participants; moderate-certainty evidence); and may not increase the number of participants who experienced at least one adverse event (RR 1.02, 95% CI 0.90 to 1.15; P = 0.79; 8 studies, 2456 participants; low-certainty evidence). Evidence showing a decrease in the number of people absent from childcare centre, school, or work due to acute URTIs with probiotics is very uncertain (RR 0.14, 95% CI 0.03 to 0.59; 1 study, 80 participants; very low-certainty evidence). Adverse events from probiotics were minor, and most commonly gastrointestinal symptoms, such as vomiting, flatulence, diarrhoea, and bowel pain.  AUTHORS' CONCLUSIONS: Overall, we found that probiotics were better than placebo or no treatment in preventing acute URTIs.

[Update of the recommendations of the Pneumonia Zero project]

La pandemia por el SARS-Cov-2 ha impactado negativamente en la aplicación de las recomendaciones de Neumonía Zero y se ha acompañado de un incremento de las tasas de Neumonía asociada a ventilación mecánica (NAVM) en las unidades de cuidados intensivos de España. Con el objetivo de disminuir las tasas actuales a 7 episodios por 1000 días de VM, se han actualizado las recomendaciones del proyecto inicial.

Se identificaron, 27 medidas que se clasificaron en 12 medidas funcionales (posición semisentada, higiene estricta de manos, entrenamiento para manipular la vía aérea, valoración diaria de posible extubación, protocolización del destete, traqueostomía precoz, ventilación no invasiva, vigilancia microbiológica, cambio de tubuladuras, humidificación, fisioterapia respiratoria, nutrición enteral postpilórica), 7 mecánicas (control de la presión del neumotaponamiento, tubos con aspiración subglótica, nutrición con sondas de bajo calibre/en intestino delgado, aspiración de secreciones con circuitos cerrados/abiertos, filtros respiratorios, cepillado de dientes, técnicas de presión negativa en la aspiración de secreciones) y 8 farmacológicas (descontaminación selectiva digestiva, descontaminación orofaríngea, ciclo corto de antibióticos, higiene de boca con clorhexidina, antibióticos inhalados, rotación de antibióticos, probióticos, anticuerpos monoclonales).

Cada medida se analizó de forma independiente, por al menos dos miembros del grupo de trabajo, mediante una revisión sistemática de la literatura y una revisión iterativa de las recomendaciones de las sociedades científicas y/o grupos de expertos.

Para la clasificación de la calidad de la evidencia y fuerza de las recomendaciones se siguió la propuesta del grupo GRADE. Para determinar el grado de recomendación, cada medida fue puntuada por todos los miembros del grupo de trabajo en relación con su efectividad, tolerabilidad y aplicabilidad en las UCI españolas a corto plazo de tiempo. Se solicitó el apoyo de expertos externos en alguna de las medidas que se revisaron. Se seleccionaron aquellas medidas que alcanzaron la máxima puntuación.

Use of selective gut decontamination in critically ill children: protocol for the Paediatric Intensive Care and Infection Control (PICnIC) pilot study

INTRODUCTION

Healthcare-associated infections (HCAIs) are a major cause of morbidity and mortality in critically ill children. In critically ill adults, there are data that suggest the use of Selective Decontamination of the Digestive tract (SDD), alongside standard infection control measures reduce mortality and the incidence of HCAIs. SDD-enhanced infection control has not been compared directly with standard infection prevention strategies in the Paediatric Intensive Care Unit (PICU) population. The aim of this pilot study is to determine the feasibility of conducting a multicentre cluster randomised controlled trial (cRCT) in critically ill children comparing SDD with standard infection control.

METHODS AND ANALYSIS

Paediatric Intensive Care and Infection Control is a parallel group pilot cRCT, with integrated mixed-methods study, comparing incorporation of SDD into infection control procedures to standard care. After a 1-week pretrial ecology surveillance period, recruitment to the cRCT will run for a period of 18 weeks, comprising: (1) baseline control period (2) pre, mid and post-trial ecology surveillance periods and (3) intervention period. Six PICUs (in England, UK) will begin with usual care in period 1, then will be randomised 1:1 by the trial statistician using computer-based randomisation, to either continue to deliver usual care or commence delivery of the intervention (SDD) in period 2. Outcomes measures include parent and healthcare professionals' views on trial feasibility, adherence to the SDD intervention, estimation of recruitment rate and understanding of potential patient-centred primary and secondary outcome measures for the definitive trial. The planned recruitment for the cRCT is 324 participants.

ETHICS AND DISSEMINATION

The trial received favourable ethical opinion from West Midlands-Black Country Research Ethics Committee (reference: 20/WM/0061) and approval from the Health Research Authority (IRAS number: 239324). Informed consent is not required for SDD intervention or anonymised data collection but is sought for investigations as part of the study, any identifiable data collected and monitoring of medical records. Results will be disseminated via publications in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

ISRCTN40310490.

Topical antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving mechanical ventilation

BACKGROUND

Patients treated with mechanical ventilation in intensive care units (ICUs) have a high risk of developing respiratory tract infections (RTIs). Ventilator-associated pneumonia (VAP) has been estimated to affect 5% to 40% of patients treated with mechanical ventilation for at least 48 hours. The attributable mortality rate of VAP has been estimated at about 9%. Selective digestive decontamination (SDD), which consists of the topical application of non-absorbable antimicrobial agents to the oropharynx and gastroenteric tract during the whole period of mechanical ventilation, is often used to reduce the risk of VAP. A related treatment is selective oropharyngeal decontamination (SOD), in which topical antibiotics are applied to the oropharynx only. This is an update of a review first published in 1997 and updated in 2002, 2004, and 2009.

OBJECTIVES

To assess the effect of topical antibiotic regimens (SDD and SOD), given alone or in combination with systemic antibiotics, to prevent mortality and respiratory infections in patients receiving mechanical ventilation for at least 48 hours in ICUs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, PubMed, and Embase on 5 February 2020. We also searched the WHO ICTRP and ClinicalTrials.gov for ongoing and unpublished studies on 5 February 2020. All searches included non-English language literature. We handsearched references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs assessing the efficacy and safety of topical prophylactic antibiotic regimens in adults receiving intensive care and mechanical ventilation. The included studies compared topical plus systemic antibiotics versus placebo or no treatment; topical antibiotics versus no treatment; and topical plus systemic antibiotics versus systemic antibiotics.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included a total of 41 trials involving 11,004 participants (five new studies were added in this update). The minimum duration of mechanical ventilation ranged from 2 (19 studies) to 6 days (one study). Thirteen studies reported the mean length of ICU stay, ranging from 11 to 33 days. The percentage of immunocompromised patients ranged from 0% (10 studies) to 22% (1 study). The reporting quality of the majority of included studies was very poor, so we judged more than 40% of the studies as at unclear risk of selection bias. We judged all studies to be at low risk of performance bias, though 47.6% were open-label, because hospitals usually have standardised infection control programmes, and possible subjective decisions on who should be tested for the presence or absence of RTIs are unlikely in an ICU setting. Regarding detection bias, we judged all included studies as at low risk for the outcome mortality. For the outcome RTIs, we judged all double-blind studies as at low risk of detection bias. We judged five open-label studies as at high risk of detection bias, as the diagnosis of RTI was not based on microbiological exams; we judged the remaining open-label studies as at low risk of detection bias, as a standardised set of diagnostic criteria, including results of microbiological exams, were used. Topical plus systemic antibiotic prophylaxis reduces overall mortality compared with placebo or no treatment (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.73 to 0.96; 18 studies; 5290 participants; high-certainty evidence). Based on an illustrative risk of 303 deaths in 1000 people this equates to 48 (95% CI 15 to 79) fewer deaths with topical plus systemic antibiotic prophylaxis. Topical plus systemic antibiotic prophylaxis probably reduces RTIs (RR 0.43, 95% CI 0.35 to 0.53; 17 studies; 2951 participants; moderate-certainty evidence). Based on an illustrative risk of 417 RTIs in 1000 people this equates to 238 (95% CI 196 to 271) fewer RTIs with topical plus systemic antibiotic prophylaxis. Topical antibiotic prophylaxis probably reduces overall mortality compared with no topical antibiotic prophylaxis (RR 0.96, 95% CI 0.87 to 1.05; 22 studies, 4213 participants; moderate-certainty evidence). Based on an illustrative risk of 290 deaths in 1000 people this equates to 19 (95% CI 37 fewer to 15 more) fewer deaths with topical antibiotic prophylaxis. Topical antibiotic prophylaxis may reduce RTIs (RR 0.57, 95% CI 0.44 to 0.74; 19 studies, 2698 participants; low-certainty evidence). Based on an illustrative risk of 318 RTIs in 1000 people this equates to 137 (95% CI 83 to 178) fewer RTIs with topical antibiotic prophylaxis. Sixteen studies reported adverse events and dropouts due to adverse events, which were poorly reported with sparse data. The certainty of the evidence ranged from low to very low.

AUTHORS' CONCLUSIONS

Treatments based on topical prophylaxis probably reduce respiratory infections, but not mortality, in adult patients receiving mechanical ventilation for at least 48 hours, whereas a combination of topical and systemic prophylactic antibiotics reduces both overall mortality and RTIs. However, we cannot rule out that the systemic component of the combined treatment provides a relevant contribution in the observed reduction of mortality. No conclusion can be drawn about adverse events as they were poorly reported with sparse data.

Prevention of severe infectious complications after colorectal surgery using preoperative orally administered antibiotic prophylaxis (PreCaution): study protocol for a randomized controlled trial

BACKGROUND

Colorectal surgery is frequently complicated by surgical site infections (SSIs). The most important consequences of SSIs are prolonged hospitalization, an increased risk of surgical reintervention and an increase in mortality. Perioperative intravenously administered antibiotic prophylaxis is the standard of care to reduce the risk of SSIs. In the last few decades, preoperative orally administered antibiotics have been suggested as additional prophylaxis to further reduce the risk of infection, but are currently not part of routine practice in most hospitals. The objective of this study is to evaluate the efficacy of a preoperative orally administered antibiotic prophylaxis (Pre-OP) in addition to intravenously administered perioperative antibiotic prophylaxis to reduce the incidence of deep SSIs and/or mortality after elective colorectal surgery.

METHODS/DESIGN

The PreCaution trial is designed as a multicenter, double-blind, randomized, placebo-controlled clinical trial that will be carried out in The Netherlands. Adult patients who are scheduled for elective colorectal surgery are eligible to participate. In total, 966 patients will be randomized to receive the study medication. This will either be Pre-OP, a solution that consists of tobramycin and colistin sulphate, or a placebo solution. The study medication will be administered four times daily during the 3 days prior to surgery. Perioperative intravenously administered antibiotic prophylaxis will be administered to all patients in accordance with national infection control guidelines. The primary endpoint of the study is the cumulative incidence of deep SSIs and/or mortality within 30 days after surgery. Secondary endpoints include both infectious and non-infectious complications of colorectal surgery, and will be evaluated 30 days and/or 6 months after surgery.

DISCUSSION

To date, conclusive evidence on the added value of preoperative orally administered antibiotic prophylaxis in colorectal surgery is lacking. The PreCaution trial should determine the effects of orally administered antibiotics in preventing infectious complications in elective colorectal surgery.

TRIAL REGISTRATION

Netherlands Trial Register, ID: NTR6113 . Registered on 11 October 2016; EudraCT 2015-005736-17.

Aspiration and the Risk of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is a major concern in the intensive care unit. It is estimated that the risk of developing VAP may be as high as 1% per ventilated day, and the attributable mortality approaches 50% in some series. A growing body of evidence implicates the role of microaspiration of contaminated oropharyngeal and perhaps gastroesophageal secretions into the airways as an integral step in the pathogenesis of VAP. In patients who have been intubated and mechanically ventilated for >72 hours, the majority of VAP is caused by enteric gram-negative organisms, presumably of gastrointestinal origin. As a result, strategies designed to minimize the risk of these contaminated secretions into the normally sterile airways are of paramount importance in terms of VAP prevention. This review highlights the important etiological role of the gut in the development of VAP and also discusses the evidence behind interventions that may modulate the risk of both aspiration and subsequent VAP.

Antibiotics for ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a significant cause of morbidity and mortality, complicating the medical course of approximately 10% of mechanically-ventilated patients, with an estimated attributable mortality of 13%. To treat VAP empirically, the American Thoracic Society currently recommends antibiotic therapy based on the patients' risk of colonisation by an organism with multidrug resistance. The selection of initial antibiotic therapy in VAP is important, as inappropriate initial antimicrobial treatment is associated with higher mortality and longer hospital stay in intensive care unit (ICU) patients.While guidelines exist for the antibiotic treatment of hospital-acquired pneumonia (HAP) from the American Thoracic Society and the British Society for Antimicrobial Chemotherapy, there are many limitations in the quality of available evidence. This systematic review aimed to summarise the results of all randomised controlled trials (RCTs) that compare empirical antibiotic regimens for VAP.

OBJECTIVES

The primary objective of this review was to assess the effect of different empirical antimicrobial therapies on the survival and clinical cure of adult patients with ventilator-associated pneumonia (VAP). Secondary objectives included reporting the incidence of adverse events, new superinfections, length of hospital stay, and length of intensive care unit (ICU) stay associated with these therapies.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, CINAHL and Web of Science to December 2015; we searched ClinicalTrials.gov to September 2016.

SELECTION CRITERIA

Two review authors independently assessed RCTs comparing empirical antibiotic treatments of VAP in adult patients, where VAP was defined as new-onset pneumonia that developed more than 48 hours after endotracheal intubation. Physicians and researchers were not required to be blinded for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted study data. We pooled studies and analysed them in two ways. We examined monotherapy, or a single experimental antimicrobial drug, versus combination therapy, or multiple experimental antimicrobial drugs. We also examined carbapenem therapy versus non-carbapenem therapy.

MAIN RESULTS

We included 12 studies with 3571 participants. All included studies examined the empiric use of one antimicrobial regimen versus another for the treatment of adults with VAP, but the particular drug regimens examined by each study varied. There was potential for bias because some studies did not report outcomes for all participants. All but one study reported sources of funding or author affiliations with pharmaceutical companies.We found no statistical difference in all-cause mortality between monotherapy and combination therapy (N = 4; odds ratio (OR) monotherapy versus combination 0.97, 95% confidence interval (CI) 0.73 to 1.30), clinical cure (N = 2; OR monotherapy versus combination 0.88, 95% CI 0.56 to 1.36), length of stay in ICU (mean difference (MD) 0.65, 95% CI 0.07 to 1.23) or adverse events (N = 2; OR monotherapy versus combination 0.93, 95% CI 0.68 to 1.26). We downgraded the quality of evidence for all-cause mortality, adverse events, and length of ICU stay to moderate for this comparison. We determined clinical cure for this comparison to be of very low-quality evidence.For our second comparison of combination therapy with optional adjunctives only one meta-analysis could be performed due to a lack of trials comparing the same antibiotic regimens. Two studies compared tigecycline versus imipenem-cilastatin for clinical cure in the clinically evaluable population and there was a statistically significant increase in clinical cure for imipenem-cilastatin (N = 2; OR tigecycline versus imipenem-cilastatin 0.44, 95% CI 0.23 to 0.84). Of importance, this effect was due to a single study.We found no statistical difference in all-cause mortality between carbapenem and non-carbapenem therapies (N = 1; OR carbapenem versus non-carbapenem 0.59, 95% CI 0.30 to 1.19) or adverse events (N = 3; OR carbapenem versus non-carbapenem 0.78, 95% CI 0.56 to 1.09), but we found that carbapenems are associated with a statistically significant increase in the clinical cure (N = 3; OR carbapenem versus non-carbapenem 1.53, 95% CI 1.11 to 2.12 for intention-to-treat (ITT) analysis and N = 2; OR carbapenem versus non-carbapenem 2.29, 95% CI 1.19 to 4.43 for clinically evaluable patients analysis). For this comparison we downgraded the quality of evidence for mortality, and clinical cure (ITT and clinically evaluable populations) to moderate. We determined the quality of evidence for adverse events to be low.

AUTHORS' CONCLUSIONS

We did not find a difference between monotherapy and combination therapy for the treatment of people with VAP. Since studies did not identify patients with increased risk for multidrug-resistant bacteria, these data may not be generalisable to all patient groups. However, this is the largest meta-analysis comparing monotherapy to multiple antibiotic therapies for VAP and contributes further evidence to the safety of using effective monotherapy for the empiric treatment of VAP.Due to lack of studies, we could not evaluate the best antibiotic choice for VAP, but carbapenems as a class may result in better clinical cure than other tested antibiotics.

Probiotics for preventing acute upper respiratory tract infections

BACKGROUND

Probiotics may improve a person's health by regulating their immune function. Some trials have shown that probiotic strains can prevent respiratory infections. Even though the previous version of our review showed benefits of probiotics for acute upper respiratory tract infections (URTIs), several new studies have been published.

OBJECTIVES

To assess the effectiveness and safety of probiotics (any specified strain or dose), compared with placebo, in the prevention of acute URTIs in people of all ages, at risk of acute URTIs.

SEARCH METHODS

We searched CENTRAL (2014, Issue 6), MEDLINE (1950 to July week 3, 2014), EMBASE (1974 to July 2014), Web of Science (1900 to July 2014), the Chinese Biomedical Literature Database, which includes the China Biological Medicine Database (from 1978 to July 2014), the Chinese Medicine Popular Science Literature Database (from 2000 to July 2014) and the Masters Degree Dissertation of Beijing Union Medical College Database (from 1981 to July 2014). We also searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for completed and ongoing trials on 31 July 2014.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics with placebo to prevent acute URTIs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and quality of trials, and extracted data using the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 13 RCTs, although we could only extract data to meta-analyse 12 trials, which involved 3720 participants including children, adults (aged around 40 years) and older people. We found that probiotics were better than placebo when measuring the number of participants experiencing episodes of acute URTI (at least one episode: odds ratio (OR) 0.53; 95% confidence interval (CI) 0.37 to 0.76, P value < 0.001, low quality evidence; at least three episodes: OR 0.53; 95% CI 0.36 to 0.80, P value = 0.002, low quality evidence); the mean duration of an episode of acute URTI (mean difference (MD) -1.89; 95% CI -2.03 to -1.75, P value < 0.001, low quality evidence); reduced antibiotic prescription rates for acute URTIs (OR 0.65; 95% CI 0.45 to 0.94, moderate quality evidence) and cold-related school absence (OR 0.10; 95% CI 0.02 to 0.47, very low quality evidence). Probiotics and placebo were similar when measuring the rate ratio of episodes of acute URTI (rate ratio 0.83; 95% CI 0.66 to 1.05, P value = 0.12, very low quality evidence) and adverse events (OR 0.88; 95% CI 0.65 to 1.19, P value = 0.40, low quality evidence). Side effects of probiotics were minor and gastrointestinal symptoms were the most common. We found that some subgroups had a high level of heterogeneity when we conducted pooled analyses and the evidence level was low or very low quality.

AUTHORS' CONCLUSIONS

Probiotics were better than placebo in reducing the number of participants experiencing episodes of acute URTI, the mean duration of an episode of acute URTI, antibiotic use and cold-related school absence. This indicates that probiotics may be more beneficial than placebo for preventing acute URTIs. However, the quality of the evidence was low or very low.

Topical antibiotics as a major contextual hazard toward bacteremia within selective digestive decontamination studies: a meta-analysis

BACKGROUND

Among methods for preventing pneumonia and possibly also bacteremia in intensive care unit (ICU) patients, Selective Digestive Decontamination (SDD) appears most effective within randomized concurrent controlled trials (RCCT's) although more recent trials have been cluster randomized. However, of the SDD components, whether protocolized parenteral antibiotic prophylaxis (PPAP) is required, and whether the topical antibiotic actually presents a contextual hazard, remain unresolved. The objective here is to compare the bacteremia rates and patterns of isolates in SDD-RCCT's versus the broader evidence base.

METHODS

Bacteremia incidence proportion data were extracted from component (control and intervention) groups decanted from studies investigating antibiotic (SDD) or non-antibiotic methods of VAP prevention and summarized using random effects meta-analysis of study and group level data. A reference category of groups derived from purely observational studies without any prevention method under study provided a benchmark incidence.

RESULTS

Within SDD RCCTs, the mean bacteremia incidence among concurrent component groups not exposed to PPAP (27 control; 17.1%; 13.1-22.1% and 12 intervention groups; 16.2%; 9.1-27.3%) is double that of the benchmark bacteremia incidence derived from 39 benchmark groups (8.3; 6.8-10.2%) and also 20 control groups from studies of non-antibiotic methods (7.1%; 4.8 - 10.5). There is a selective increase in coagulase negative staphylococci (CNS) but not in Pseudomonas aeruginosa among bacteremia isolates within control groups of SDD-RCCT's versus benchmark groups with data available.

CONCLUSIONS

The topical antibiotic component of SDD presents a major contextual hazard toward bacteremia against which the PPAP component partially mitigates.

Year in review 2011: Critical Care--Resource management

Increasing complexity and costs are a fundamental problem in critical care medicine, leading researchers to study opportunities and threats to continue to provide high-quality care in a more efficient health system. Over the past decades, we have learned from industrial methods that quality improvement and resource management can help achieve these results. Last year, Critical Care published a number of papers that highlight key points of critical care resource management. Each of these is grouped into one of three broad categories, based on domains of quality: (a) outcomes, in which we review long-term outcome data with an emphasis on the aging population, strategies to help mitigate the psychological burden of critical care, adverse events, and the appropriate use of resources, such as prolonged mechanical ventilation and intensive care unit (ICU) beds; (b) processes of care, in which we review variability in the provision of critical care, owing to gender, insurance status, and delays in ICU admission; knowledge translation studies in critical care; goal-directed therapy for postoperative patients and decision-making in the ICU; and (c) structure, in which we review strategies to improve quality through changes in design and the structural limitations to provide care in resource-limited settings.

Selective decontamination of the digestive tract: the mechanism of action is control of gut overgrowth

PURPOSE

Gut overgrowth is the pathophysiological event in the critically ill requiring intensive care. In relation to the risk of developing a clinically important outcome, gut overgrowth is defined as ≥10(5) potential pathogens including 'abnormal' aerobic Gram-negative bacilli (AGNB), 'normal' bacteria and yeasts, per mL of digestive tract secretion. Surveillance samples of throat and gut are the only samples to detect overgrowth. Gut overgrowth is the crucial event which precedes both primary and secondary endogenous infection, and a risk factor for the development of de novo resistance. Selective decontamination of the digestive tract (SDD) is an antimicrobial prophylaxis designed to control overgrowth.

METHODS

There have been 65 randomised controlled trials of SDD in 15,000 patients over 25 years and 11 meta-analyses, which are reviewed.

RESULTS AND CONCLUSIONS

These trials demonstrate that the full SDD regimen using parenteral and enteral antimicrobials reduces lower airway infection by 72 %, blood stream infection by 37 %, and mortality by 29 %. Resistance is also controlled. Parenteral cefotaxime which reaches high salivary and biliary concentrations eradicates overgrowth of 'normal' bacteria such as Staphylococcus aureus in the throat. Enteral polyenes control 'normal' Candida species. Enteral polymyxin and tobramycin, eradicate, or prevent gut overgrowth of 'abnormal' AGNB. Enteral vancomycin controls overgrowth of 'abnormal' methicillin-resistant S. aureus. SDD controls overgrowth by achieving high antimicrobial concentrations effective against 'normal' and 'abnormal' potential pathogens rather than by selectivity.

Antibiotic therapy for preventing infections in patients with acute stroke

BACKGROUND

Stroke is the main cause of disability in high income countries and ranks second as a cause of death worldwide. Infections occur frequently after stroke and may adversely affect outcome. Preventive antibiotic therapy in the acute phase of stroke may reduce infections and improve outcome.

OBJECTIVES

1. To assess whether preventive antibiotic therapy in patients with acute stroke reduces the risk of dependency and death at follow-up. 2. To assess whether preventive antibiotic therapy in patients with acute stroke reduces infection rate.

SEARCH METHODS

We searched the Cochrane Stroke Group's Trials Register (October 2010); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3); MEDLINE (1950 to October 2010) and EMBASE (1980 to October 2010). In an effort to identify further published, unpublished and ongoing trials we searched trials and research registers, scanned reference lists and contacted authors, colleagues and researchers in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of preventive antibiotic therapy versus control (placebo or open control) in patients with acute ischaemic or haemorrhagic stroke.

DATA COLLECTION AND ANALYSIS

Two authors independently selected articles and performed data extraction; we discussed and resolved discrepancies in a consensus meeting with a third observer. We contacted the study authors to obtain missing data when required. An independent observer assessed methodological quality. We calculated relative risks (RRs) for dichotomous outcomes, assessed heterogeneity amongst included studies and performed subgroup analyses on study quality.

MAIN RESULTS

We included five studies involving 506 patients. Study population, study design, type of antibiotic and definition of infection differed considerably. The number of patients who died in the preventive antibiotic group was non-significantly reduced (33/248 (13%) versus 38/258 (15%), RR 0.85, 95% confidence interval (CI) 0.47 to 1.51); the number of dependent patients in the preventive antibiotic therapy group was also non-significantly reduced (97/208 (47%) versus 127/208 (61%), RR 0.67, 95% CI 0.32 to 1.43). Preventive antibiotic therapy did reduce the incidence of infections in patients with acute stroke from 36% to 22% (36/166 (22%) versus 61/169 (36%), RR 0.58, 95% CI 0.43 to 0.79). No major side-effects of preventive antibiotic therapy were reported.

AUTHORS' CONCLUSIONS

In this meta-analysis, preventive antibiotic therapy seemed to reduce the risk of infection, but did not reduce the number of dependent or deceased patients. However, the included studies were small and heterogeneous. Large randomised trials are urgently needed.

Prevention of ventilator-associated pneumonia, mortality and all intensive care unit acquired infections by topically applied antimicrobial or antiseptic agents: a meta-analysis of randomized controlled trials in intensive care units

INTRODUCTION

Given the high morbidity and mortality attributable to ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, prevention plays a key role in the management of patients undergoing mechanical ventilation. One of the candidate preventive interventions is the selective decontamination of the digestive or respiratory tract (SDRD) by topical antiseptic or antimicrobial agents. We performed a meta-analysis to investigate the effect of topical digestive or respiratory tract decontamination with antiseptics or antibiotics in the prevention of VAP, of mortality and of all ICU-acquired infections in mechanically ventilated ICU patients.

METHODS

A meta-analysis of randomised controlled trials was performed. The U.S. National Library of Medicine's MEDLINE database, Embase, and Cochrane Library computerized bibliographic databases, and reference lists of selected studies were used. Selection criteria for inclusion were: randomised controlled trials (RCTs); primary studies; examining the reduction of VAP and/or mortality and/or all ICU-acquired infections in ICU patients by prophylactic use of one or more of following topical treatments: 1) oropharyngeal decontamination using antiseptics or antibiotics, 2) gastrointestinal tract decontamination using antibiotics, 3) oropharyngeal plus gastrointestinal tract decontamination using antibiotics and 4) respiratory tract decontamination using antibiotics; reported enough data to estimate the odds ratio (OR) or risk ratio (RR) and their variance; English language; published through June 2010.

RESULTS

A total of 28 articles met all inclusion criteria and were included in the meta-analysis. The overall estimate of efficacy of topical SDRD in the prevention of VAP was 27% (95% CI of efficacy = 16% to 37%) for antiseptics and 36% (95% CI of efficacy = 18% to 50%) for antibiotics, whereas in none of the meta-analyses conducted on mortality was a significant effect found. The effect of topical SDRD in the prevention of all ICU-acquired infections was statistically significant (efficacy = 29%; 95% CI of efficacy = 14% to 41%) for antibiotics whereas the use of antiseptics did not show a significant beneficial effect.

CONCLUSIONS

Topical SDRD using antiseptics or antimicrobial agents is effective in reducing the frequency of VAP in ICU. Unlike antiseptics, the use of topical antibiotics seems to be effective also in preventing all ICU-acquired infections, while the effectiveness on mortality of these two approaches needs to be investigated in further research.

A study of the perceived risks, benefits and barriers to the use of SDD in adult critical care units (the SuDDICU study)

BACKGROUND

Hospital acquired infections are a major cause of morbidity and mortality and markedly increased health care costs. Critically ill patients who require management in an Intensive Care Unit are particularly susceptible to these infections which are associated with a very high mortality. Selective decontamination of the digestive tract (SDD) may reduce these infections and improve mortality but it has not been widely adopted into practice. We aim to 1. Clarify reasons why clinicians have avoided implementing SDD into clinical practice despite the current best-evidence 2. Describe barriers to SDD implementation and 3. Identify what further evidence is required before full scale clinical implementation would be considered appropriate and feasible.

METHODS

We have developed an international 'multi-lens' approach to investigate SDD from several perspectives. In case studies we will identify accounts of implementation of SDD in practice, in terms of the behaviours performed by the full range of individual clinicians, accounts of how SDD was first introduced into the Unit and specific content that may be used to populate the content of behaviour change techniques to be used in an implementation intervention and procedures to consider in order to deliver an implementation trial. In a 4 round Delphi study we will identify the range of stakeholders' beliefs, views and perceived barriers relating to the use of SDD. We will generate hypotheses about key beliefs about SDD and will inform the feasibility of any future randomised controlled trial. In large-scale nationwide postal questionnaire surveys of the state of current practice we will identify the factors predicting acceptability of an effectiveness or implementation trial using, and informed by, the theoretical domains structure. In semi-structured interviews with active international clinical trialists we will assess the feasibility of a randomised controlled trial and identify challenges and barriers to undertaking research in the field of SDD research.

DISCUSSION

We believe these methods will allow us to determine whether clinical implementation trials or further large effectiveness trials are required before full scale implementation into clinical practice.

Selective decontamination of the digestive tract reduces pneumonia and mortality

Selective decontamination of the digestive tract (SDD) has been subject of numerous randomized controlled trials in critically ill patients. Almost all clinical trials showed SDD to prevent pneumonia. Nevertheless, SDD has remained a controversial strategy. One reason for why clinicians remained reluctant to implement SDD into daily practice could be that mortality was reduced in only 2 trials. Another reason could be the heterogeneity of trials of SDD. Indeed, many different prophylactic antimicrobial regimes were tested, and dissimilar diagnostic criteria for pneumonia were applied amongst the trials. This heterogeneity impeded interpretation and comparison of trial results. Two other hampering factors for implementation of SDD have been concerns over the risk of antimicrobial resistance and fear for escalation of costs associated with the use of prophylactic antimicrobials. This paper describes the concept of SDD, summarizes the results of published trials of SDD in mixed medical-surgical intensive care units, and rationalizes the risk of antimicrobial resistance and rise of costs associated with this potentially life-saving preventive strategy.

Physicians' and nurses' opinions on selective decontamination of the digestive tract and selective oropharyngeal decontamination: a survey

Introduction

Use of selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) in intensive care patients has been controversial for years. Through regular questionnaires we determined expectations concerning SDD (effectiveness) and experience with SDD and SOD (workload and patient friendliness), as perceived by nurses and physicians.

Methods

A survey was embedded in a group-randomized, controlled, cross-over multicenter study in the Netherlands in which, during three 6-month periods, SDD, SOD or standard care was used in random order. At the end of each study period, all nurses and physicians from participating intensive care units received study questionnaires.

Results

In all, 1024 (71%) of 1450 questionnaires were returned by nurses and 253 (82%) of 307 by physicians. Expectations that SDD improved patient outcome increased from 71% and 77% of respondents after the first two study periods to 82% at the end of the study (P = 0.004), with comparable trends among nurses and physicians. Nurses considered SDD to impose a higher workload (median 5.0, on a scale from 1 (low) to 10 (high)) than SOD (median 4.0) and standard care (median 2.0). Both SDD and SOD were considered less patient friendly than standard care (medians 4.0, 4.0 and 6.0, respectively). According to physicians, SDD had a higher workload (median 5.5) than SOD (median 5.0), which in turn was higher than standard care (median 2.5). Furthermore, physicians graded patient friendliness of standard care (median 8.0) higher than that of SDD and SOD (both median 6.0).

Conclusions

Although perceived effectiveness of SDD increased as the trial proceeded, both among physicians and nurses, SOD and SDD were, as compared to standard care, considered to increase workload and to reduce patient friendliness. Therefore, education about the importance of oral care and on the effects of SDD and SOD on patient outcomes will be important when implementing these strategies.

Trial registration

ISRCTN35176830.

Impact of digestive and oropharyngeal decontamination on the intestinal microbiota in ICU patients

PURPOSE

Selective digestive microbial decontamination (SDD) is hypothesized to benefit patients in intensive care (ICU) by suppressing Gram-negative potential pathogens from the colon without affecting the anaerobic intestinal microbiota. The purpose of this study was to provide more insight to the effects of digestive tract and oropharyngeal decontamination on the intestinal microbiota by means of a prospective clinical trial in which faecal samples were collected from ICU patients for intestinal microbiota analysis.

METHODS

The faecal samples were collected from ICU patients enrolled in a multicentre trial to study the outcome of SDD and selective oral decontamination (SOD) in comparison with standard care (SC). Fluorescent in situ hybridization (FISH) was used to analyze the faecal microbiota. The numbers of bacteria from different bacterial groups were compared between the three regimens.

RESULTS

The total counts of bacteria per gram faeces did not differ between regimens. The F. prausnitzii group of bacteria, representing an important group among intestinal microbiota, was significantly reduced in the SDD regimen compared to the SC and SOD. The Enterobacteriaceae were significantly suppressed during SDD compared to both SOD and SC; enterococci increased in SDD compared to both other regimens.

CONCLUSIONS

The composition of the intestinal microbiota is importantly affected by SDD. The F. prausnitzii group was significantly suppressed during SDD. This group of microbiota is a predominant producer of butyrate, the main energy source for colonocytes. Reduction of this microbiota is an important trade-off while reducing gram-negative bacteria by SDD.

Pneumonia

Hospital-acquired pneumonia (HAP) is usually caused by bacterial, viral, or fungal pathogens that occur ≥48 h after hospital admission.^1,2 Overall, more than 80% of HAP episodes are related to invasive airway management (in patients with endotracheal intubation or tracheostomy) with mechanical ventilation, which is known as ventilator-associated pneumonia (VAP).³ VAP is defined as pneumonia developing more than 48 h after intubation and mechanical ventilation. Healthcare-associated pneumonia (HCAP) is part of the continuum of pneumonia, which includes patients who were hospitalized in an acute-care hospital for ≥2 days within 90 days of the infection; resided in a long-term care facility; received recent intravenous antibiotic therapy, chemotherapy, or wound care within the past 30 days of the current infection; or attended a hospital or hemodialysis clinic.^1,2 Although this document focuses more on HAP and VAP, many of the principles are also relevant to the management of HCAP. HAP, VAP, and HCAP are the second most common nosocomial infections after urinary tract infection, but are the leading causes of mortality due to hospital-acquired infections.^4,5

Antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving intensive care

BACKGROUND

Pneumonia is an important cause of mortality in intensive care units (ICUs). The incidence of pneumonia in ICU patients ranges between 7% and 40%, and the crude mortality from ventilator-associated pneumonia may exceed 50%. Although not all deaths in patients with this form of pneumonia are directly attributable to pneumonia, it has been shown to contribute to mortality in ICUs independently of other factors that are also strongly associated with such deaths.

OBJECTIVES

To assess the effects of prophylactic antibiotic regimens, such as selective decontamination of the digestive tract (SDD) for the prevention of respiratory tract infections (RTIs) and overall mortality in adults receiving intensive care.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 1), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register; MEDLINE (January 1966 to March 2009); and EMBASE (January 1990 to March 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of antibiotic prophylaxis for RTIs and deaths among adult ICU patients.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

We included 36 trials involving 6914 people. There was variation in the antibiotics used, patient characteristics and risk of RTIs and mortality in the control groups. In trials comparing a combination of topical and systemic antibiotics, there was a significant reduction in both RTIs (number of studies = 16, odds ratio (OR) 0.28, 95% confidence interval (CI) 0.20 to 0.38) and total mortality (number of studies = 17, OR 0.75, 95% CI 0.65 to 0.87) in the treated group. In trials comparing topical antimicrobials alone (or comparing topical plus systemic versus systemic alone) there was a significant reduction in RTIs (number of studies = 17, OR 0.44, 95% CI 0.31 to 0.63) but not in total mortality (number of studies = 19, OR 0.97, 95% CI 0.82 to 1.16) in the treated group.

AUTHORS' CONCLUSIONS

A combination of topical and systemic prophylactic antibiotics reduces RTIs and overall mortality in adult patients receiving intensive care. Treatment based on the use of topical prophylaxis alone reduces respiratory infections but not mortality. The risk of resistance occurring as a negative consequence of antibiotic use was appropriately explored only in one trial which did not show any such effect.

Perioperative selective decontamination of the digestive tract (SDD) in elective colorectal surgery

BACKGROUND

Selective decontamination of the digestive tract (SDD) decreases morbidity and mortality in critically ill patients and morbidity in patients undergoing esophageal resection. This study analyzes the effect of perioperative SDD in patients undergoing elective colorectal surgery on postoperative infections and anastomotic leakage.

METHODS

This is a retrospective analysis of prospectively collected data in a 3-year cohort of 162 patients undergoing elective resection of colon and or rectum. Of these patients, 76 (47%) received SDD (polymyxine B sulfate, tobramycin, and amphotericin) perioperatively. The control group consisted of 86 patients who were not treated with SDD. Postoperative complications, hospital stay, and mortality were analyzed.

RESULTS

In the SDD group, there were six patients (7.9%) with infectious complications compared with 17 patients (19.8%) in the control group (p = 0.031). The incidence of the combined endpoint infectious complications and anastomotic leakage was 8 (11%) in the SDD group vs. 22 (26%) in the control group (p = 0.014). Multivariate analysis showed that no-SDD, aged above 60 years and diabetes were independent predictors of postoperative complications.

CONCLUSION

Perioperative SDD in elective colorectal surgery seems to reduce postoperative surgical complications including infectious complications and anastomotic leakage. Prospective, randomized, placebo-controlled studies are needed to confirm this conclusion.

[Nosocomial infection indicators]

Nosocomial infection indicators are a reflection of healthcare quality and patient safety in hospitals. Infection indicators are calculated using surveillance programs and/or systems. Current nosocomial infection surveillance systems are based on both prevalence and incidence studies. Since 1990 the EPINE prevalence study, promoted by the Spanish Society for Preventive Medicine, Public Health and Hygiene, has developed 25 nosocomial infection indicators in hospital patients in Spain. And since 1994 the ENVIN-HELICS incidence study, promoted by the Infectious Diseases Working Group of the Spanish Society for Intensive and Critical Care Medicine and Coronary Units, has developed nine ICU-acquired infection indicators in critical patients. Participation in both surveillance systems is voluntary and has gradually increased over the years. These two control systems present the results of two different situations in the area of nosocomial infection and each complements the other; in addition, they have helped to train health professionals and to raise their awareness of nosocomial infection and patient safety. This article presents the indicators obtained in 2007 through both surveillance programs as well as their standards of reference.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarize evidence relating to efficacy and safety of health care interventions accurately and reliably. The clarity and transparency of these reports, however, is not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users.Since the development of the QUOROM (QUality Of Reporting Of Meta-analysis) Statement--a reporting guideline published in 1999--there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realizing these issues, an international group that included experienced authors and methodologists developed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions.The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this Explanation and Elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA Statement, this document, and the associated Web site (http://www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarise evidence relating to efficacy and safety of healthcare interventions accurately and reliably. The clarity and transparency of these reports, however, are not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users. Since the development of the QUOROM (quality of reporting of meta-analysis) statement-a reporting guideline published in 1999-there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realising these issues, an international group that included experienced authors and methodologists developed PRISMA (preferred reporting items for systematic reviews and meta-analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions. The PRISMA statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this explanation and elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA statement, this document, and the associated website (www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

Do Selective Digestive Decontamination (SDD) and Selective Oral Decontamination (SOD) Affect Mortality?

In this cluster-randomised, multicentre study, topical plus systemic SDD and SOD reduced the incidence of death, with numbers needed to treat of 29 and 34, after statistical correction for baseline imbalance due to the cluster design of the study.

Level of evidence: 1++ (RCT with very low risk of bias)

Strategies to prevent ventilator-associated pneumonia in acute care hospitals

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections. The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their ventilator-associated pneumonia (VAP) prevention efforts. Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary and Introduction and accompanying editorial for additional discussion.

1. Occurrence of VAP in acute care facilities.

a. VAP is one of the most common infections acquired by adults and children in intensive care units (ICUs).

i. In early studies, it was reported that 10%-20% of patients undergoing ventilation developed VAP. More-recent publications report rates of VAP that range from 1 to 4 cases per 1,000 ventilator-days, but rates may exceed 10 cases per 1,000 ventilator-days in some neonatal and surgical patient populations. The results of recent quality improvement initiatives, however, suggest that many cases of VAP might be prevented by careful attention to the process of care.

2. Outcomes associated with VAP

a. VAP is a cause of significant patient morbidity and mortality, increased utilization of healthcare resources, and excess cost.

i. The mortality attributable to VAP may exceed 10%.

ii. Patients with VAP require prolonged periods of mechanical ventilation, extended hospitalizations, excess use of antimicrobial medications, and increased direct medical costs.

Ventilator-associated tracheobronchitis: the impact of targeted antibiotic therapy on patient outcomes

Nosocomial lower respiratory tract infections are a common cause of morbidity and mortality in ICU patients receiving mechanical ventilation. Many studies have investigated the management and prevention of ventilator-associated pneumonia (VAP), but few have focused on the role of ventilator-associated tracheobronchitis (VAT). The pathogenesis of lower respiratory tract infections often begins with tracheal colonization that may progress to VAT, and in selected patients to VAP. Since there is no well-established definition of VAT, discrimination between VAT and VAP can be challenging. VAT is a localized disease with clinical signs (fever, leukocytosis, and purulent sputum), microbiologic information (Gram stain with bacteria and leukocytes, with either a positive semiquantitative or a quantitative sputum culture), and the absence of a new infiltrate on chest radiograph. Monitoring endotracheal aspirates has been used to identify and quantify pathogens colonizing the lower airway, to diagnose VAT or VAP, and to initiate early, targeted antibiotic therapy. Recent data suggest that VAT appears to be an important risk factor for VAP and that targeted antibiotic therapy for VAT may be a new paradigm for VAP prevention and better patient outcomes.

Evidence-based algorithms for diagnosing and treating ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is widely recognized as a serious and common complication associated with high morbidity and high costs. Given the complexity of caring for heterogeneous populations in the intensive care unit (ICU), however, there is still uncertainty regarding how to diagnose and manage VAP.

OBJECTIVE

We recently conducted a national collaborative aimed at reducing health care-associated infections in ICUs of hospitals operated by the Hospital Corporation of America (HCA). As part of this collaborative, we developed algorithms for diagnosing and treating VAP in mechanically ventilated patients. In the current article, we (1) review the current evidence for diagnosing VAP, (2) describe our approach for developing these algorithms, and (3) illustrate the utility of the diagnostic algorithms using clinical teaching cases.

DESIGN

This was a descriptive study, using data from a national collaborative focused on reducing VAP and catheter-related bloodstream infections.

SETTING

The setting of the study was 110 ICUs at 61 HCA hospitals.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

We assembled an interdisciplinary team that included infectious disease specialists, intensivists, hospitalists, statisticians, critical care nurses, and pharmacists. After reviewing published studies and the Centers for Disease Control and Prevention VAP guidelines, the team iteratively discussed the evidence, achieved consensus, and ultimately developed these practical algorithms. The diagnostic algorithms address infant, pediatric, immunocompromised, and adult ICU patients.

CONCLUSIONS

We present practical algorithms for diagnosing and managing VAP in mechanically ventilated patients. These algorithms may provide evidence-based real-time guidance to clinicians seeking a standardized approach to diagnosing and managing this challenging problem.

Guidelines for the management of hospital-acquired pneumonia in the UK: report of the working party on hospital-acquired pneumonia of the British Society for Antimicrobial Chemotherapy

These evidence-based guidelines have been produced after a systematic literature review of a range of issues involving prevention, diagnosis and treatment of hospital-acquired pneumonia (HAP). Prevention is structured into sections addressing general issues, equipment, patient procedures and the environment, whereas in treatment, the structure addresses the use of antimicrobials in prevention and treatment, adjunctive therapies and the application of clinical protocols. The sections dealing with diagnosis are presented against the clinical, radiological and microbiological diagnosis of HAP. Recommendations are also made upon the role of invasive sampling and quantitative microbiology of respiratory secretions in directing antibiotic therapy in HAP/ventilator-associated pneumonia.

Clinical review: airway hygiene in the intensive care unit

Maintenance of airway secretion clearance, or airway hygiene, is important for the preservation of airway patency and the prevention of respiratory tract infection. Impaired airway clearance often prompts admission to the intensive care unit (ICU) and can be a cause and/or contributor to acute respiratory failure. Physical methods to augment airway clearance are often used in the ICU but few are substantiated by clinical data. This review focuses on the impact of oral hygiene, tracheal suctioning, bronchoscopy, mucus-controlling agents, and kinetic therapy on the incidence of hospital-acquired respiratory infections, length of stay in the hospital and the ICU, and mortality in critically ill patients. Available data are distilled into recommendations for the maintenance of airway hygiene in ICU patients.

Profound effect of study design factors on ventilator-associated pneumonia incidence of prevention studies: benchmarking the literature experience

BACKGROUND

The ventilator-associated pneumonia incident proportion (VAP-IP) is highly variable among control groups of studies of methods for its prevention. The objective here is to develop and validate a literature-derived benchmark against which these groups can be profiled.

METHODS

A literature search yielded 95 cohort groups and control and intervention groups of 150 studies of either non-antimicrobial or antimicrobial methods of VAP prevention. The 95 cohort groups comprise a benchmark set (30 groups), from which the reference funnel plot (RFP) was derived, and a search set (65 groups), against which the benchmark was validated. The VAP-IP data of the benchmark set were found in five published systematic reviews, whereas the VAP-IP data of the search set were abstracted directly from the literature.

FINDINGS

Among the 95 cohort groups, the VAP-IP of groups with size >399 was significantly lower than the VAP-IP of smaller groups. Compared with the RFP, 15 of 51 (29%) control groups from studies of antimicrobial methods of VAP prevention with concurrent design were high outlier versus 2 of 110 (2%) control groups from other types of study design (P < 0.001). There were only 22 (14%) outlier groups, all low outlier, among the 162 intervention groups.

CONCLUSIONS

Study design factors such as concurrency and study size have potentially greater influence on the VAP-IP than do the VAP prevention methods under study. The outlier status of control groups were inapparent in the individual studies and the meta-analyses and yet would have confounded the estimates of treatment effect.

Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock: 2008

OBJECTIVE

To provide an update to the original Surviving Sepsis Campaign clinical management guidelines, "Surviving Sepsis Campaign guidelines for management of severe sepsis and septic shock," published in 2004.

DESIGN

Modified Delphi method with a consensus conference of 55 international experts, several subsequent meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee. This process was conducted independently of any industry funding.

METHODS

We used the GRADE system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations. A strong recommendation indicates that an intervention's desirable effects clearly outweigh its undesirable effects (risk, burden, cost), or clearly do not. Weak recommendations indicate that the tradeoff between desirable and undesirable effects is less clear. The grade of strong or weak is considered of greater clinical importance than a difference in letter level of quality of evidence. In areas without complete agreement, a formal process of resolution was developed and applied. Recommendations are grouped into those directly targeting severe sepsis, recommendations targeting general care of the critically ill patient that are considered high priority in severe sepsis, and pediatric considerations.

RESULTS

Key recommendations, listed by category, include: early goal-directed resuscitation of the septic patient during the first 6 hrs after recognition (1C); blood cultures prior to antibiotic therapy (1C); imaging studies performed promptly to confirm potential source of infection (1C); administration of broad-spectrum antibiotic therapy within 1 hr of diagnosis of septic shock (1B) and severe sepsis without septic shock (1D); reassessment of antibiotic therapy with microbiology and clinical data to narrow coverage, when appropriate (1C); a usual 7-10 days of antibiotic therapy guided by clinical response (1D); source control with attention to the balance of risks and benefits of the chosen method (1C); administration of either crystalloid or colloid fluid resuscitation (1B); fluid challenge to restore mean circulating filling pressure (1C); reduction in rate of fluid administration with rising filing pressures and no improvement in tissue perfusion (1D); vasopressor preference for norepinephrine or dopamine to maintain an initial target of mean arterial pressure > or = 65 mm Hg (1C); dobutamine inotropic therapy when cardiac output remains low despite fluid resuscitation and combined inotropic/vasopressor therapy (1C); stress-dose steroid therapy given only in septic shock after blood pressure is identified to be poorly responsive to fluid and vasopressor therapy (2C); recombinant activated protein C in patients with severe sepsis and clinical assessment of high risk for death (2B except 2C for post-operative patients). In the absence of tissue hypoperfusion, coronary artery disease, or acute hemorrhage, target a hemoglobin of 7-9 g/dL (1B); a low tidal volume (1B) and limitation of inspiratory plateau pressure strategy (1C) for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure in acute lung injury (1C); head of bed elevation in mechanically ventilated patients unless contraindicated (1B); avoiding routine use of pulmonary artery catheters in ALI/ARDS (1A); to decrease days of mechanical ventilation and ICU length of stay, a conservative fluid strategy for patients with established ALI/ARDS who are not in shock (1C); protocols for weaning and sedation/analgesia (1B); using either intermittent bolus sedation or continuous infusion sedation with daily interruptions or lightening (1B); avoidance of neuromuscular blockers, if at all possible (1B); institution of glycemic control (1B) targeting a blood glucose < 150 mg/dL after initial stabilization ( 2C ); equivalency of continuous veno-veno hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1A); use of stress ulcer prophylaxis to prevent upper GI bleeding using H2 blockers (1A) or proton pump inhibitors (1B); and consideration of limitation of support where appropriate (1D). Recommendations specific to pediatric severe sepsis include: greater use of physical examination therapeutic end points (2C); dopamine as the first drug of choice for hypotension (2C); steroids only in children with suspected or proven adrenal insufficiency (2C); a recommendation against the use of recombinant activated protein C in children (1B).

CONCLUSION

There was strong agreement among a large cohort of international experts regarding many level 1 recommendations for the best current care of patients with severe sepsis. Evidenced-based recommendations regarding the acute management of sepsis and septic shock are the first step toward improved outcomes for this important group of critically ill patients.

[Selective digestive decontamination. Why don't we apply the evidence in the clinical practice?]

Selective digestive decontamination (SDD) is a prophylactic strategy whose objective is to reduce the incidence of infections, mainly mechanical ventilation associated pneumonia in patients who require intensive cares, preventing or eradicating the oropharyngeal and gastrointestinal carrier state of potentially pathogenic microorganisms. Fifty-four randomized clinical trials (RCTs) and 9 meta-analysis have evaluated SDD. Thirty eight RCTs show a significant reduction of the infections and 4 of mortality. All the meta-analyses show a significant reduction of the infections and 5 out of the 9 meta-analyses report a significant reduction in mortality. Thus, 5 patients from the ICU with SDD must be treated to prevent pneumonia and 12 patients from the ICU should be treated to prevent one death. The data that show benefit of the SDD on mortality have an evidence grade 1 or recommendation grade A (supported by at least two level 1 investigations). The aim of this review is to explain the pathogeny of infections in critical patients, describe selective digestive decontamination, analyze the evidence available on it efficacy and the potential adverse effects and discuss the reasons published by the experts who advise against the use of SDD, even though it is recognized as the best intervention evaluated in intensive cares to reduce morbidity and mortality of the infections.

Ventilator-associated pneumonia in neonatal and pediatric intensive care unit patients

Ventilator-associated pneumonia (VAP) is the second most common hospital-acquired infection among pediatric intensive care unit (ICU) patients. Empiric therapy for VAP accounts for approximately 50% of antibiotic use in pediatric ICUs. VAP is associated with an excess of 3 days of mechanical ventilation among pediatric cardiothoracic surgery patients. The attributable mortality and excess length of ICU stay for patients with VAP have not been defined in matched case control studies. VAP is associated with an estimated $30,000 in attributable cost. Surveillance for VAP is complex and usually performed using clinical definitions established by the CDC. Invasive testing via bronchoalveolar lavage increases the sensitivity and specificity of the diagnosis. The pathogenesis in children is poorly understood, but several prospective cohort studies suggest that aspiration and immunodeficiency are risk factors. Educational interventions and efforts to improve adherence to hand hygiene for children have been associated with decreased VAP rates. Studies of antibiotic cycling in pediatric patients have not consistently shown this measure to prevent colonization with multidrug-resistant gram-negative rods. More consistent and precise approaches to the diagnosis of pediatric VAP are needed to better define the attributable morbidity and mortality, pathophysiology, and appropriate interventions to prevent this disease.

Oral decontamination for prevention of pneumonia in mechanically ventilated adults: systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of oral decontamination on the incidence of ventilator associated pneumonia and mortality in mechanically ventilated adults.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, CINAHL, the Cochrane Library, trials registers, reference lists, conference proceedings, and investigators in the specialty.

REVIEW METHODS

Two independent reviewers screened studies for inclusion, assessed trial quality, and extracted data. Eligible trials were randomised controlled trials enrolling mechanically ventilated adults that compared the effects of daily oral application of antibiotics or antiseptics with no prophylaxis.

RESULTS

11 trials totalling 3242 patients met the inclusion criteria. Among four trials with 1098 patients, oral application of antibiotics did not significantly reduce the incidence of ventilator associated pneumonia (relative risk 0.69, 95% confidence interval 0.41 to 1.18). In seven trials with 2144 patients, however, oral application of antiseptics significantly reduced the incidence of ventilator associated pneumonia (0.56, 0.39 to 0.81). When the results of the 11 trials were pooled, rates of ventilator associated pneumonia were lower among patients receiving either method of oral decontamination (0.61, 0.45 to 0.82). Mortality was not influenced by prophylaxis with either antibiotics (0.94, 0.73 to 1.21) or antiseptics (0.96, 0.69 to 1.33) nor was duration of mechanical ventilation or stay in the intensive care unit.

CONCLUSIONS

Oral decontamination of mechanically ventilated adults using antiseptics is associated with a lower risk of ventilator associated pneumonia. Neither antiseptic nor antibiotic oral decontamination reduced mortality or duration of mechanical ventilation or stay in the intensive care unit.