Incidence of gastroesophageal reflux and aspiration in mechanically ventilated patients using small-bore nasogastric tubes

Rebound Inverts the Staphylococcus aureus Bacteremia Prevention Effect of Antibiotic Based Decontamination Interventions in ICU Cohorts with Prolonged Length of Stay

Could rebound explain the paradoxical lack of prevention effect against Staphylococcus aureus blood stream infections (BSIs) with antibiotic-based decontamination intervention (BDI) methods among studies of ICU patients within the literature? Two meta-regression models were applied, each versus the group mean length of stay (LOS). Firstly, the prevention effects against S. aureus BSI [and S. aureus VAP] among 136 studies of antibiotic-BDI versus other interventions were analyzed. Secondly, the S. aureus BSI [and S. aureus VAP] incidence in 268 control and intervention cohorts from studies of antibiotic-BDI versus that among 165 observational cohorts as a benchmark was modelled. In model one, the meta-regression line versus group mean LOS crossed the null, with the antibiotic-BDI prevention effect against S. aureus BSI at mean LOS day 7 (OR 0.45; 0.30 to 0.68) inverted at mean LOS day 20 (OR 1.7; 1.1 to 2.6). In model two, the meta-regression line versus group mean LOS crossed the benchmark line, and the predicted S. aureus BSI incidence for antibiotic-BDI groups was 0.47; 0.09-0.84 percentage points below versus 3.0; 0.12-5.9 above the benchmark in studies with 7 versus 20 days mean LOS, respectively. Rebound within the intervention groups attenuated and inverted the prevention effect of antibiotic-BDI against S. aureus VAP and BSI, respectively. This explains the paradoxical findings.

[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.

Twenty-Four-Hour Esophageal pH Measurement in Mechanically Ventilated Children: A Prospective Cohort Study

OBJECTIVES

To assess the prevalence of gastroesophageal reflux in mechanically ventilated children using 24-hour esophageal pH-metry and its role as a risk factor for ventilator-associated pneumonia.

DESIGN

Prospective cohort study.

SETTING

PICU of a tertiary care hospital from North India.

PATIENTS

Mechanically ventilated children 1-15 years old in PICU from July 2015 to June 2017, excluding those receiving acid suppressants, known cases of gastroesophageal reflux disease, having upper gastrointestinal bleed.

INTERVENTION

Demographic details, baseline investigations, diagnosis, treatment details, and Pediatric Risk of Mortality III score were recorded at enrollment. Gastroesophageal reflux was evaluated using 24-hour esophageal pH-metry. Children were followed up for 7 days or 48 hours after extubation for development of ventilator-associated pneumonia using Centers for Disease Control and Prevention criteria. Pathologic acidic gastroesophageal reflux was defined as fall in esophageal pH less than 4 for more than 4% of total time, whereas pathologic alkaline gastroesophageal reflux as rise in esophageal pH greater than 7 for more than 17% of total time.

MEASUREMENTS AND MAIN RESULTS

Sixty-one children (median [interquartile range], age 73 mo [30-132 mo]; 44 boys [72%]) were enrolled. Median Pediatric Risk of Mortality III score was 10.0 (3-16). Median duration of ventilation was 6 days (3-9 d). Pathologic gastroesophageal reflux (acidic or alkaline) was present in 47 children (77%). Twelve children (19.7%) met criteria for pathologic acidic gastroesophageal reflux, whereas 44 children (72.1%) had pathologic alkaline gastroesophageal reflux; nine children (14.7%) had both pathologic acidic and alkaline gastroesophageal reflux. Of the enrolled children, 17 (27.9 %) developed ventilator-associated pneumonia. No patient had both pathologic acidic gastroesophageal reflux and ventilator-associated pneumonia. Of 17 children who developed ventilator-associated pneumonia, 12 (70.5%) had pathologic alkaline gastroesophageal reflux as compared to 32 children (72.7%) among the 44 children who did not develop ventilator-associated pneumonia (p = 0.87).

CONCLUSIONS

The current study shows high incidence of gastroesophageal reflux on 24-hour esophageal pH-metry in mechanically ventilated children with medical diagnoses. The significance of this finding and its impact on ventilator-associated pneumonia and other ventilator-associated events need to be examined in larger studies.

Analysis of Pepsin Concentration and Influencing Factors in Saliva of Elderly Nasal Feeding Patients

Background

Elderly patients receiving nasal feeding have weaker physiological function, and placement of a nasogastric tube weakens the natural barrier of the cardia-esophageal sphincter; therefore, the risk of gastroesophageal reflux (GER) is higher. Many studies have shown that pepsin is extremely sensitive in predicting GERD, so this study intends to investigate the level of pepsin in saliva of elderly patients with nasal feeding and analyze its influencing factors.

Methods

This was a cross-sectional study. Patients admitted to the Chinese PLA General Hospital from April 2018 to October 2018 who received nasal feeding were included. One ml of saliva was collected from each patient in while sitting during fasting in the morning and 1 hour after lunch for 3 consecutive days. Pepsin was quantified by enzyme-linked immunosorbent assay (ELISA). The patients were predivided into two groups (≥7.75μg/ml or <7.75μg/ml) based on the median pepsin. Baseline and clinical factors were compared.

Results

The mean age of the patients was 91.09 ± 4.91 years. There were statistical differences in diabetes and feeding methods between the two groups. There was a positive correlation between the morning and postprandial pepsin levels (r = 0.442, P < 0.001), and has no statistical difference (P = 0.175). Multivariate analysis showed that the risk factors for higher pepsin levels were diabetes (odds ratio (OR): 2.67; 95% CI: 1.225-5.819, P = 0.013) and nasal feeding methods (OR: 2.475; 95% CI: 1.183-5.180, P=0.016).

Conclusions

For patients undergoing nasal feeding who are older than 80 years, the fasting and 1-hour postprandial pepsin concentration were consistent. Diabetes and feeding methods are risk factors for high pepsin levels. For the elderly over 80 years old, age has no influence on pepsin concentration.

World-Wide Variation in Incidence of Staphylococcus aureus Associated Ventilator-Associated Pneumonia: A Meta-Regression

Staphylococcus aureus (S. aureus) is a common Ventilator-Associated Pneumonia (VAP) isolate. The objective here is to define the extent and possible reasons for geographic variation in the incidences of S. aureus-associated VAP, MRSA-VAP and overall VAP. A meta-regression model of S. aureus-associated VAP incidence per 1000 Mechanical Ventilation Days (MVD) was undertaken using random effects methods among publications obtained from a search of the English language literature. This model incorporated group level factors such as admission to a trauma ICU, year of publication and use of bronchoscopic sampling towards VAP diagnosis. The search identified 133 publications from seven worldwide regions published over three decades. The summary S. aureus-associated VAP incidence was 4.5 (3.9–5.3) per 1000 MVD. The highest S. aureus-associated VAP incidence is amongst reports from the Mediterranean (mean; 95% confidence interval; 6.1; 4.1–8.5) versus that from Asian ICUs (2.1; 1.5–3.0). The incidence of S. aureus-associated VAP varies by up to three-fold (for the lowest versus highest incidence) among seven geographic regions worldwide, whereas the incidence of VAP varies by less than two-fold. Admission to a trauma unit is the most important group level correlate for S. aureus-associated VAP.

Unusually High Incidences of Staphylococcus aureus Infection within Studies of Ventilator Associated Pneumonia Prevention Using Topical Antibiotics: Benchmarking the Evidence Base

Selective digestive decontamination (SDD, topical antibiotic regimens applied to the respiratory tract) appears effective for preventing ventilator associated pneumonia (VAP) in intensive care unit (ICU) patients. However, potential contextual effects of SDD on Staphylococcus aureus infections in the ICU remain unclear. The S. aureus ventilator associated pneumonia (S. aureus VAP), VAP overall and S. aureus bacteremia incidences within component (control and intervention) groups within 27 SDD studies were benchmarked against 115 observational groups. Component groups from 66 studies of various interventions other than SDD provided additional points of reference. In 27 SDD study control groups, the mean S. aureus VAP incidence is 9.6% (95% CI; 6.9–13.2) versus a benchmark derived from 115 observational groups being 4.8% (95% CI; 4.2–5.6). In nine SDD study control groups the mean S. aureus bacteremia incidence is 3.8% (95% CI; 2.1–5.7) versus a benchmark derived from 10 observational groups being 2.1% (95% CI; 1.1–4.1). The incidences of S. aureus VAP and S. aureus bacteremia within the control groups of SDD studies are each higher than literature derived benchmarks. Paradoxically, within the SDD intervention groups, the incidences of both S. aureus VAP and VAP overall are more similar to the benchmarks.

Enteral nutrition volume is not correlated with lower respiratory tract infection in patients on mechanical ventilation

OBJECTIVE

To evaluate the effect of enteral nutrition volume, gastrointestinal function and the type of acid suppressive drug upon the incidence of lower respiratory tract infections in critically ill patients on mechanical ventilation (MV).

DESIGN

A retrospective secondary analysis was carried out.

SETTING

The Intensive Care Unit of a University Hospital.

PATIENTS OR PARTICIPANTS

Patients≥18-years-old expected to need MV for more than four days, and receiving enteral nutrition by nasogastric tube within 24h of starting MV.

INTERVENTIONS

We correlated enteral nutrition volume administered during the first 10 days, gastrointestinal function and the type of acid suppressive therapy with the episodes of lower respiratory tract infection up until day 28. Cox proportional hazards ratios in univariate and adjusted multivariate models were used. Statistical significance was considered for p<0.05.

MAIN VARIABLES OF INTEREST

Lower respiratory tract infection episodes.

RESULTS

Sixty-six out of 185 patients (35.7%) had infection; 27 patients had ventilator-associated pneumonia; and 39 presented ventilator-associated tracheobronchitis. Uninfected and infected groups were similar in terms of enteral nutrition volume (54±12 and 54±9mL/h; p=0.94) and caloric intake (19.4±4.9 and 19.6±5.2kcal/kg/d; p=0.81). The Cox proportional hazards model showed neurological indication of MV to be the only independent variable related to infection (p=0.001). Enteral nutrition volume, the type of acid suppressive therapy, and the use of prokinetic agents were not significantly correlated to infection.

CONCLUSIONS

Enteral nutrition volume and caloric intake, gastrointestinal dysfunction and the type of acid suppressive therapy used were not associated to lower respiratory tract infection in patients on MV.

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.

Comparison of Two Different Enteral Nutrition Protocol in Critically Ill Patients

OBJECTIVE

In this study, two enteral nutrition protocols with different gastric residual volumes (GRVs) and different monitoring intervals were compared with respect to gastrointestinal intolerance findings in intensive care unit (ICU) patients.

METHODS

The study was carried out prospectively in 60 patients in the anaesthesiology and reanimation ICU under mechanical ventilation support, who were scheduled to take enteral feeding. Patients were sequentially divided into two groups: Group 1, GRV threshold of 100 mL, and monitoring interval of 4 hours, and Group 2, GRV threshold of 200 mL, monitoring interval of 8 hours. To test the significant difference between the groups, Student's t test, chi-square text and Fisher exact test were used.

RESULTS

In Group 1, 3.3% vomiting, 6.6% diarrhoea was observed; in Group 2, 16.6% vomiting, 10% diarrhoea. In terms of total intolerance (vomiting and/or diarrhoea) of the two groups, the incidence was significantly higher in Group 2 (33.3%) than in Group 1 (10%) (p=0.02).

CONCLUSION

According to the results of the study, a lower gastrointestinal intolerance rate was detected in the GRV threshold 100 mL, monitoring interval for 4 hours protocol (Group 1) than in GRV threshold 200 mL, monitoring interval for 8 hours protocol (Group 2); Group 1 may be preferred renovation.

Obese ICU Patients

This project described prospectively obese, critically ill patients and the resources critical care nurses used to care for these challenging patients. It also examined the relationship between resources used by nurses and patient outcomes, including complications and length of stay. Forty-three participants were enrolled. Patients with a body mass index (BMI) 40 kg/m2 used the majority of equipment and personnel resources and experienced a prolonged length of stay. The most common equipment used was a specialty bed or mattress; the most common complications were related to the pulmonary system. Initial use of multiple resources may indicate a patient at risk for adverse outcomes. Nurses can use findings to anticipate care needs and develop interventions, such as optimal positioning, to avoid adverse outcomes.

Gastroesophageal reflux in critically ill patients

Gastroesophageal reflux (GER) is a common occurrence in critically ill, mechanically ventilated patients. Reflux can lead to pulmonary aspiration of gastric contents and subsequent pneumonia. Several characteristics of patients, interventions provided in the intensive care unit setting, and factors associated with feeding increase a patient's risk for reflux. Critical care nurses and clinical nurse specialists can identify patients at highest risk for GER by utilizing the patient's history, reviewing the medications, and assessing the current status to provide interventions to reduce the risk of GER and its sequelae of aspiration pneumonia. This article reviews the physiology of GER, risk factors, and interventions to decrease GER in the critically ill patient.

Gastroesophageal reflux in critically ill children: a review

Gastroesophageal reflux (GER) is very common in children due to immaturity of the antireflux barrier. In critically ill patients there is also a high incidence due to a partial or complete loss of pressure of the lower esophageal sphincter though other factors, such as the use of nasogastric tubes, treatment with adrenergic agonists, bronchodilators, or opiates and mechanical ventilation, can further increase the risk of GER. Vomiting and regurgitation are the most common manifestations in infants and are considered pathological when they have repercussions on the nutritional status. In critically ill children, damage to the esophageal mucosa predisposes to digestive tract hemorrhage and nosocomial pneumonia secondary to repeated microaspiration. GER is mainly alkaline in children, as is also the case in critically ill pediatric patients. pH-metry combined with multichannel intraluminal impedance is therefore the technique of choice for diagnosis. The proton pump inhibitors are the drugs of choice for the treatment of GER because they have a greater effect, longer duration of action, and a good safety profile.

Implementing a unit-level intervention to reduce the probability of ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is the second most common hospital-acquired infection and is associated with high morbidity and mortality rates for mechanically ventilated patients in the intensive care unit. Routine nursing interventions have been shown to reduce VAP rates.

OBJECTIVES

The purpose of this study was to evaluate the effectiveness of a unit-specific education intervention that emphasized hand hygiene, head-of-the-bed elevation, and oral care. The goals were to improve staff compliance with hand washing, head-of-the-bed elevation, and oral care; to decrease VAP rates, and to decrease number of ventilator days.

METHODS

Two-hour observations were conducted on a convenience sample of 100 ventilated patients not diagnosed with VAP and the clinical staff that interacted with them. Instrumentation included a compliance checklist, a demographic patient survey, and the Acute Physiology and Chronic Health Evaluation AEIV tool. Unit-specific educational interventions were designed and implemented on each participating unit.

RESULTS

: The VAP and the ventilator day rates did not improve significantly. There were no significant changes in clinician adherence to hand hygiene, provision of oral care, or patient positioning.

DISCUSSION

Despite implementation of both structured and creative education, team-based approach, and frequent staff reminders, patient outcomes and staff compliance did not improve significantly. Unit-based education interventions may not be the best strategy to facilitate change. Organizations with frequent changes in personnel and leadership may not have the unit-level infrastructure necessary to attain and sustain change.

Nutritional aspects of care

Malnutrition in the oral and maxillofacial surgery surgical patient can have critical implications in the overall well-being and prognosis of the long-term, hospitalized, ill patient. The OMS should be capable of assessing the patient's nutritional status and nutritional requirements and developing appropriate recommendations for proper nutritional management. Knowledge of the various modalities of nutritional support should be readily available to the OMS practitioner.

Gastroesophageal reflux in mechanically ventilated pediatric patients and its relation to ventilator-associated pneumonia

INTRODUCTION

The objective was to determine the frequency of gastroesophageal reflux (GER) in mechanically ventilated pediatric patients and its role as a risk factor for ventilator-associated pneumonia (VAP), which may be enhanced among those patients.

METHODS

The study is a prospective cohort study of mechanically ventilated pediatric patients in the pediatric intensive care unit (PICU) of Ain Shams University Children's Hospital. It was conducted in 24 mechanically ventilated patients (16 of them developed VAP and 8 did not, with mean age of 16.6 +/- 20.5 and 18.6 +/- 22.4 months respectively). Esophageal 24-hour pH-metry beside clinical and laboratory evaluation of their underlying problem and severity of their condition were carried out.

RESULTS

All VAP patients had GER (50% alkaline reflux, 12.5% acidic reflux and 37.5% combined reflux) compared to 75% of non-VAP ones (100% alkaline reflux). The mean total reflux time was significantly longer among VAP (50 minutes) versus non-VAP (3 minutes) patients. There was significant increase in acidic reflux parameters among non-survivors versus survivors (P < 0.001). For VAP mortality, total acidic reflux at a cut-off value of 28.6 minutes is found to be a mortality predictor with a sensitivity of 100% and a specificity of 100%.

CONCLUSIONS

GER is a constant incident in mechanically ventilated pediatric patients, with alkaline reflux being more common than acidic reflux. Both acidic and alkaline refluxes were found to be associated with the development of VAP and total reflux time was found to be a reliable predictor of VAP. Moreover, acidic reflux was found to be more related to mortality than alkaline reflux.

Gastric versus post-pyloric feeding: relationship to tolerance, pneumonia risk, and successful delivery of enteral nutrition

Enteral nutrition has been shown to have clinical advantages over parenteral nutrition in critically ill patients. However, delivery of enteral nutrition can be challenging because of intolerance and potential adverse effects. Gastric feeding is more physiologic than post-pyloric feeding, but its use may be limited by intolerance due to gastric dysfunction and by inappropriately low gastric residual volumes. Post-pyloric feeding may help to overcome these disadvantages by making it possible to avoid feeding interruption and potentially reduce the risk of aspiration. Results from studies to date have not shown any advantage of post-pyloric over gastric feeding in regard to outcome. This article focuses on strategies for enteral nutrition delivery in critically ill patients. The selection of site for enteral feeding should be based on risks, patient tolerance, and availability of local expertise. Predetermined feeding protocols may help to optimize the delivery of enteral nutrition. Only sufficient and safe delivery of enteral nutrition will have a positive impact on patient outcome.

Decreasing aspiration risk with enteral feeding

Aspiration is a clinical concern in patients receiving enteral tube feeding. Aspiration can result in pneumonia leading to increases in the use of antibiotics, length of hospital stay, and the risk of mortality. Pneumonia caused by aspiration of gastric contents is of particular concern in patients who require mechanical ventilation and feeding by nasogastric tube. This article summarizes factors that might influence the development of aspiration pneumonia and minimize risk, such as the position of the patient's body, method of feeding, and size of the feeding tube.

Selecting the most appropriate route of feeding

This article provides an overview of the various methods available for providing nutritional support. The various techniques available for both enteral and parenteral access are discussed. The selection of the most appropriate route of nutritional support is highly individual and recommendations are made regarding the factors that should be considered by the patient and the clinician in the decision-making process.

Adoption of a Ventilator-Associated Pneumonia Clinical Practice Guideline

CONCEPTUAL FRAMEWORK

The Academic Center for Evidence-based Practice (ACE) Star Model was used to implement an evidence-based clinical practice guideline (CPG) in order to decrease ventilator-associated pneumonia (VAP) incidence rates and ventilator days. The goal was to interrupt person-to-person transmission of bacteria and bacterial colonization using low-cost, evidence-based strategies to prevent VAP. DISCOVERY: Two geographically proximate medical centers, inclusive of five intensive care units located in the southwestern region of the United States had significant variations in their VAP rates.

EVIDENCE SUMMARY

Using the U.S. Preventive Services Task Force grading criteria, the results of 69 studies were used to establish a clinical practice guideline to prevent ventilator-associated pneumonia. TRANSLATION: A clinical practice guideline was developed for the prevention of VAP and included five nursing activities: (a) head-of-bed elevation; (b) oral care; (c) ventilator tubing condensate removal; (d) hand hygiene; and (e) glove use. The effect of the CPG, inclusive of an educational intervention, was measured using an observational, prospective, quasi-experimental design. INTEGRATION: A multidisciplinary education team developed a self-learning packet, educational materials, and storyboards for the staff as dissemination strategies. Strategies also included e-mail, one-on-one teaching with clinicians, and feedback on guideline adoption and VAP rate reports.

EVALUATION

Observation data were collected to evaluate adoption of the CPG while caring for 106 ventilated patients. VAP rates changed at both hospitals although the change was not statistically significant. Additionally, the ICU length of stay declined at both facilities, causing cost savings.

DISCUSSION

These results support the idea that adoption of evidence-based practices contributes to decreased VAP rates. For a successful program, ICU leaders should emphasize strategies that routinize adoption of evidence-based CPGs.

Initial and delayed onset of acute respiratory failure: factors associated with development and outcome

In a prospective observational study of 1038 adult admissions to a 31-bed medical/surgical intensive care unit (ICU), acute respiratory failure (ARF, defined as a Pao(2)/Fio(2) ratio <or=200 mm Hg and the need for respiratory support) occurred in 182 (58%) of the 313 admissions with an ICU stay of more than 48 h. Initial ARF (onset within 48 h of ICU admission) occurred in 133 (42%) patients, and delayed onset ARF (onset >48 h after ICU admission) in 49 (16%). On admission, the cardiovascular sequential organ failure assessment (SOFA) score was higher in initial than in delayed onset ARF (1.1 +/- 1.5 vs 0.6 +/- 1.2, P < 0.05). High admission serum C-reactive protein concentrations (OR 1.08, 95% CI 1.04-1.12, P = 0.0001) and SOFA scores (OR 1.20, 95% CI 1.08-1.33, P = 0.0007) were the factors independently associated with initial ARF, and a low Glasgow coma scale (GCS) score (OR 1.13, 95% CI 1.04-1.21, P = 0.0018) was associated with delayed onset ARF. In initial ARF, a high SOFA score (OR 1.24, 95% CI 1.12-1.38, P = 0.0001) and a low GCS score (OR 0.89, 95% CI 0.83-0.96, P = 0.0013) on admission, and in delayed onset ARF, a low GCS score at 48 h (OR 0.67, 95% CI 0.54-0.84, P = 0.0011) were independently associated with death. The mortality rate was similar for initial and delayed onset ARF.

Gastric microbiota in elderly patients fed via nasogastric tubes for prolonged periods

Aspiration of oropharyngeal contents is a constant threat for elderly patients fed via a nasogastric tube (NGT). Colonization of the oropharynx of these patients by pathological flora and the development of biofilms on the feeding tube has been documented recently. In addition, the presence of the NGT may interfere with the gastro-oesophageal sphincter, leading to gastro-oesophageal reflux. Thus, the passage of pathogenic bacteria in both directions is facilitated. The purpose of this study was to explore the microbiota of the gastric juice and the oropharynx in NGT-fed elderly patients. Samples of gastric juice were drawn after an overnight fast, and microbial cultures and direct pH measurement were performed. Concomitant cultures were obtained from the oropharynx. Overall, 107 gastric and oropharyngeal cultures were obtained from 52 subjects. Pathogenic flora (Gram-negative bacteria or Staphylococcus aureus) were isolated from 74% of stomach samples and from 69% of oropharynx samples. Proteus spp. (26%) and Escherichia coli (22%) were the most common isolates in the gastric juice, and Proteus spp. (24%) and Pseudomonas spp. (21%) were the most common isolates in the oropharynx. Similarity in the composition of the oropharynx and gastric flora was observed in most cases. The gastric pH was relatively high (4.57 +/- 0.65 at 3 h after feeding and 4.2 +/- 0.9 at 12 h after feeding) and was highly correlated with the isolation of pathogenic bacteria (r = 0.58, P < 0.01). These results support the view that in addition to the oropharynx, the stomach of NGT-fed elderly patients constitutes a reservoir of pathogens that could be associated with the risk of aspiration pneumonia. The cause of the high gastric pH and its relation to pathogenic bacteria warrants further study.

Effect of percutaneous endoscopic gastrostomy on gastro-esophageal reflux in mechanically-ventilated patients

AIM: To investigate the effect of percutaneous endoscopic gastrostomy (PEG) on gastroesophageal reflux (GER) in mechanically-ventilated patients.

METHODS: In a prospective, randomized, controlled study 36 patients with recurrent or persistent ventilator-associated pneumonia (VAP) and GER > 6% were divided into PEG group (n = 16) or non-PEG group (n  = 20). Another 11 ventilated patients without reflux (GER < 3%) served as control group. Esophageal pH-metry was performed by the “pull through” method at baseline, 2 and 7 d after PEG. Patients were strictly followed up for semi-recumbent position and control of gastric nutrient residue.

RESULTS: A significant decrease of median (range) reflux was observed in PEG group from 7.8 (6.2 - 15.6) at baseline to 2.7 (0 - 10.4) on d 7 post-gastrostomy (P < 0.01), while the reflux increased from 9 (6.2 - 22) to 10.8 (6.3 - 36.6) (P < 0.01) in non-PEG group. A significant correlation between GER (%) and the stay of nasogastric tube was detected (r = 0.56, P < 0.01).

CONCLUSION: Gastrostomy when combined with semi-recumbent position and absence of nutrient gastric residue reduces the gastroesophageal reflux in ventilated patients.

Beyond heartburn: a systematic review of the extra-oesophageal spectrum of reflux-induced disease

BACKGROUND

Gastro-oesophageal reflux disease (GORD) is a chronic condition affecting up to one-quarter of the Western population. GORD is characterized by heartburn and acid regurgitation, but is reported to be associated with a spectrum of extra-oesophageal symptoms.

OBJECTIVE

The aim of this systematic review was to critically evaluate postulated extra-oesophageal symptoms of GORD.

METHODS

Extra-oesophageal symptoms were identified from population-based studies evaluating their association with GORD (either defined as heartburn and/or acid regurgitation, or diagnosed in general practice). The response of these symptoms to acid-suppressive therapy was investigated using randomized, double-blind, placebo-controlled studies. Pathogenic mechanisms were evaluated using clinical and preclinical studies.

RESULTS

An association between GORD and symptoms or a diagnosis of chest pain/angina, cough, sinusitis and gall-bladder disease was evident from three eligible population-based studies of GORD. Randomized placebo-controlled studies (n=20) showed that acid-suppressive therapy provides symptomatic relief of chest pain, asthma and, potentially, chronic cough and laryngitis. Mechanistic models, based on direct physical damage by refluxate or vagally mediated reflexes, support a causal role for GORD in chest pain and respiratory symptoms, but not in gall-bladder disease.

CONCLUSION

GORD is likely to play a causal role in chest pain and possibly asthma, chronic cough and laryngitis. Further investigation is desirable, particularly for other potential extra-oesophageal manifestations of GORD such as chronic obstructive pulmonary disease, sinusitis, bronchitis and otitis. Acid-suppressive therapy is likely to benefit patients with non-cardiac chest pain, but further placebo-controlled studies are needed for other symptoms comprising the extra-oesophageal spectrum of GORD.

Clinical Issues and Research in Respiratory Failure from Severe Acute Respiratory Syndrome

The National Heart, Lung, and Blood Institute, along with the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases, convened a panel to develop recommendations for treatment, prevention, and research for respiratory failure from severe acute respiratory syndrome (SARS) and other newly emerging infections. The clinical and pathological features of acute lung injury (ALI) from SARS appear indistinguishable from ALI from other causes. The mainstay of treatments for ALI remains supportive. Patients with ALI from SARS who require mechanical ventilation should receive a lung protective, low tidal volume strategy. Adjuvant treatments recommended include prevention of venous thromboembolism, stress ulcer prophylaxis, and semirecumbent positioning during ventilation. Based on previous experience in Canada, infection control resources and protocols were recommended. Leadership structure, communication, training, and morale are an essential aspect of SARS management. A multicenter, placebo-controlled trial of corticosteroids for late SARS is justified because of widespread clinical use and uncertainties about relative risks and benefits. Studies of combined pathophysiologic endpoints were recommended, with mortality as a secondary endpoint. The group recommended preparation for studies, including protocols, ethical considerations, Web-based registries, and data entry systems.

Prevention and Treatment of Aspiration Pneumonia in Intensive Care Units

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

Aspiration Assessment and Prevention in Critically Ill Enterally Fed Patients

Providing nutrition to patients is a vitally important aspect of care. Enterally feeding even critically ill patients remains the method of choice for most prescribers; however, the decision to provide nutrition via the enteral route comes with the added concern of bronchopulmonary aspiration as a complication. The majority of the literature and research on enteral feeding is out of date and focuses primarily on ways to identify aspiration, rather then preventing it. Although much of this research and literature is not current, many valid and useful recommendations have been made that can be applied to current practice. These recommendations are synthesized in this article in an effort to improve the quality and safety of administration of enteral nutrition to critically ill patients. However, this compiled information is limited to the current resources. More research should be done to decrease the risk of aspiration in this delicate population.

Safety Issues Regarding Colonic Cleansing for Diagnostic and Surgical Procedures

There are various methods available to cleanse the colon in preparation for diagnostic and surgical procedures. The popular options are diet and cathartic regimens, gut lavage and phosphate preparations. Each method has its own unique characteristics and safety profile. Diet and cathartic regimens are based on traditional methods of colonoscopy preparation and remain an acceptable and safe alternative for patients unwilling or unable to tolerate other bowel preparations. Gut lavage methods involve ingestion of 2-4L of osmotically balanced solutions containing polyethylene glycol, which have been shown to be safe and effective for colon cleansing, including for special patient populations with cardiac, renal or hepatic dysfunction. Phosphate preparations have also been shown to be safe and effective for colon cleansing and are generally better tolerated than counterpart gut lavage solutions. However, this method has safety concerns for some patients with cardiac, renal and hepatic dysfunctions.

Methods for decreasing risk of aspiration pneumonia in critically ill patients

BACKGROUND

Pneumonia is a significant clinical concern in critically ill hospitalized patients, leading to increase in the use of antibiotics, length of hospital stay, and the risk of mortality. Pneumonia caused by aspiration of gastric contents is of particular concern in patients who need mechanical ventilation and feeding through a nasogastric tube. Therefore, methods for decreasing the risk of aspiration are very important.

METHODS

This review article summarizes factors that might influence the development of aspiration pneumonia, such as the position of the patient's body or type of hospital bed, methods of feeding, medications administered, suctioning of subglottic secretions, and bacterial decontamination.

RESULTS

Elevating the head of the bed (45 degrees), continuous subglottic suctioning, and oral decontamination seem to be effective in the prevention of aspiration pneumonia.

Risk factors for aspiration

BACKGROUND

There are numerous risk factors for aspiration in tube-fed critically ill patients. However, there is confusion about the extent to which these factors actually contribute to aspiration. The purpose of this literature review was to summarize findings from selected research studies.

METHODS

A nonexhaustive literature search was conducted to identify risk factors for aspiration in tube-fed, critically ill patients. The most commonly cited factors were decreased level of consciousness, supine position, presence of a nasogastric tube, tracheal intubation and mechanical ventilation, bolus or intermittent feeding delivery methods, high-risk disease and injury conditions, and advanced age.

RESULTS

Many studies of aspiration risk factors have relatively small sample sizes and used equivocal definitions of aspiration. Although some addressed aspiration as an outcome, others considered gastroesophageal reflux or pneumonia as outcomes. Despite these variations, authors almost uniformly agree that a decreased level of consciousness and a sustained supine position are major risk factors for aspiration. There is less agreement regarding the effect of a nasogastric tube (or its size) on aspiration and on the effect of various formula delivery methods.

CONCLUSIONS

A decreased level of consciousness is a major risk factor for aspiration, as is a sustained supine position. Although some authors favor using small-bore feeding tubes to prevent aspiration, there seems to be insufficient data to warrant this action. Although strong data are lacking regarding feeding delivery methods, there are more data to support continuous feedings than bolus/intermittent feedings in high-risk patients.

Nosocomial infections

Nosocomial infections and antimicrobial resistance are topics that have been intensely studied in human medicine because of their significant impact on human health. In recent years, concerns have been raised that the use of antibiotics in veterinary medicine, animal husbandry, and agriculture may be contributing to the development of resistance in common bacterial species affecting human beings. Although there is inadequate proof at this time that the resistance is transmitted from animals to people, if antibiotics continue to be used indiscriminately in veterinary medicine, veterinarians may find themselves facing regulations restricting the use of some antibiotics. Nosocomial infections have been reported in veterinary medicine and are likely to increase in prevalence with the increase in intensive care practices in many hospitals. Prolonged hospitalization and the use of invasive devices and procedures increase the risk of nosocomial disease. As in human medicine, organisms isolated in the nosocomial infections reported in veterinary patients have an increasingly broad spectrum of antimicrobial resistance. Despite these findings, the use of empiric and prophylactic antibiotic therapy is still widespread in veterinary medicine. Nosocomial infections and antimicrobial resistance may have a serious impact on the future of [table: see text] veterinary medicine, because the cost and ability to treat our patients may be affected by the loss of access to or effectiveness of antimicrobial drugs. Despite the millions of dollars spent on research to reduce the incidence of nosocomial infections in human patients, the strategies that have consistently proven successful are simple and inexpensive to implement. The most important factor in preventing nosocomial infections is improving the hygiene practices of health care providers. Hand-washing or the use of disposable gloves can dramatically reduce the transmission of bacteria between patients. Aseptic technique should be used in the placement and management of all invasive devices. All staff members should be educated on the risks and symptoms associated with nosocomial infections so that cases can be detected early and treated appropriately. We in the veterinary profession have the opportunity to learn from the experiences of the human medical profession and can take steps to prevent the escalation of nosocomial infections and their impact on our profession.

Feeding the intensive care patient

The present review highlights recent findings (focusing on papers published between October 1999 and December 2000) in nutritional support of intensive care unit patients. During the past year, research focused on the use of enteral nutrition versus parenteral nutrition, and on the best composition of enteral nutrition and parenteral nutrition according to the clinical condition of the patient. With regard to enteral nutrition, the pH of nutritional support, the timing of administration and the technique of tube placement were debated. Immunomodulating agents and hormonal manipulations may improve outcomes of critically ill patients, but still warrant further research before they can be recommended for routine clinical use.