Enteral nutrition in patients receiving mechanical ventilation. Multiple sources of tracheal colonization include the stomach

Ventilator-associated pneumonia prevention in the Intensive care unit using Postpyloric tube feeding in China (VIP study): study protocol for a randomized controlled trial

BACKGROUND

Ventilator-associated pneumonia is a challenge in critical care and is associated with high mortality and morbidity. Although some consensuses on preventing ventilator-associated pneumonia are reached, it is still somewhat controversial. Meta-analysis has shown that postpyloric tube feeding may reduce the incidences of ventilator-associated pneumonia, which still desires high-quality evidence. This trial aims to evaluate the efficacy and safety profiles of postpyloric tube feeding versus gastric tube feeding.

METHODS/DESIGN

In this multicenter, open-label, randomized controlled trial, we will recruit 924 subjects expected to receive mechanical ventilation for no less than 48 h. Subjects on mechanical ventilation will be randomized (1:1) to receive postpyloric or gastric tube feeding and routine preventive measures simultaneously. The primary outcome is the proportion of patients with at least one ventilator-associated pneumonia episode. Adverse events and serious adverse events will be observed closely.

DISCUSSION

The VIP study is a large-sample-sized, multicenter, open-label, randomized, parallel-group, controlled trial of postpyloric tube feeding in China and is well-designed based on previous studies. The results of this trial may help to provide evidence-based recommendations for the prevention of ventilator-associated pneumonia.

TRIAL REGISTRATION

Chictr.org.cn ChiCTR2100051593 . Registered on 28 September 2021.

Pulsed-Field Gel Electrophoresis Used for Typing of Extended-Spectrum-β-Lactamases- Producing Escherichia coli Isolated from Infant ҆S Respiratory and Digestive System

Escherichia coli infections are becoming increasingly difficult to treat because of emerging antimicrobial resistance, mostly to expanded-spectrum cephalosporins, due to the production of extended-spectrum β-lactamases (ESBLs).Despite extensive studies of ESBL- producing E.coli in adult patients, there is a lack of information about the epidemiology and spread of ESBL organisms in pediatric population. The aim of this study was to examine the gastrointestinal tract as an endogenous reservoir for the respiratory tract colonization with ESBL- E. coli in children, hospitalized because of the severity of the respiratory illness. The study group consists of 40 children with ESBL-producing E. coli strains isolated from the sputum and from the rectal samples. A control group of 15 E. coli isolated from rectal swabs of healthy children were included in the analysis. The comparison of the strains was done by using antimicrobial susceptibility patterns of the stains, and pulsed field gel electrophoresis was performed for molecular typing, using XbaI digestion. 90% of the compared pairs of strains in the study group were with identical antimicrobial susceptibility patterns and indistinguishable in 79.2% by the obtained PFGE – profiles.33.3% (5/15) of confirmed E. coli strains from the control group were found to be ESBL – producers. Resulting band profiles of all isolates demonstrated presence of 12 pulsotypes, with 100% similarity within the pulsotypes. Although, some isolates obtained from different patients were genetically indistinguishable, these strains were not hospital acquired, as none of the patients satisfied the criteria for hospital acquired pneumonia, and there was a lack of an obvious transmission chain. All ESBL –E. coli isolated from sputum in clinical cases were obtained from patients under the age of one. According to the resistance profile of the compared pairs and the PFGE comparison of all isolates, it can be concluded that the gastrointestinal tract is the main reservoir of ESBL-E. coli. Small age in infants is a risk factor for translocation of bacteria, enabling the colonization of the respiratory tract.

Critical Care Nutrition Support Best Practices: Key Differences Between Canadian and American Guidelines

Since 2015, Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition and Canadian critical care nutrition support guidelines have both been updated. Despite a similar evidentiary basis, there remain key differences between guideline recommendations. These differences in recommendations may pose confusion for the clinician and may encumber widespread applicability. The aim of this review was to enhance practitioner confidence in applying critical care nutrition support guidelines to patient care in their settings by outlining the similarities and differences between the American and Canadian methods for guideline development and describing the key differences and reasons behind the differences.

An Anthology of Advances in Enteral Tube Feeding Formulations

This article summarizes several major advances in tube feeding formulas marketed in the United States. It traces the progress in tube feeding formulas, starting with blenderized formulas to commercially available intact-nutrient formulas and culminating in the introduction of the concept of immunonutrition. The impact of packaging is also described.

When to Feed the Patient With Gastrointestinal Bleeding

Whether to provide artificial enteral nutrition therapy to a patient with evidence of gastrointestinal bleeding (GIB) creates a difficult clinical dilemma. Concern that enteral feeding may contribute to the morbidity associated with GIB leads to delays in initiating enteral therapy or to cessation of feeding in the patient in whom artificial nutrition support has already been started. Surprisingly, evidence of GIB is not an automatic contraindication to further enteral feeding. Depending on the etiology of the GIB, enteral nutrition may protect the gut mucosa and reduce further bleeding in some patients, actually increase risk for rebleeding in other patients, or serve as a moot point with no relation to further bleeding or morbidity in still other patients. In many cases, an endoscopic evaluation is needed to distinguish the differential etiology of the GIB. The nutrition support specialist needs a full understanding of the physiology behind the varying diagnoses for GIB to know whether feedings can be initiated or continued or whether enteral feedings need to be withheld for 48-72 hours until risk for rebleeding and further morbidity is minimized.

Analytic Reviews : Initiating Mechanical Ventilation

Mechanical ventilation is a central facet of intensive care medicine. Technological progress has led to major advances in this field. Initiation of mechanical ventila tion remains standard; however, many options are now available to continue mechanical ventilation. These mechanical options include assist-control ventilation, intermittent mandatory ventilation, pressure support ventilation, positive end-expiratory pressure, and high- frequency ventilation. The sophistication of ventilators has also allowed more procedures to be performed dur ing mechanical ventilation, including bronchoscopy and transbronchial biopsy. Complications do occur during mechanical ventilation, but can be minimized by vigi lance and use of proper procedures. The recent increase in home care will lead to increased use of alternatives to conventional ventilatory modes. Finally, more well- designed studies are needed as newer techniques are promoted.

Multiple System Organ Failure in the Adult Respiratory Distress Syndrome

Recently completed studies suggest that patients with the adult respiratory distress syndrome (ARDS) manifest early evidence of multiple-site endothelial injury. Ex trapulmonary disease is usually the cause of death in these patients. Furthermore, prognosis in individual cases of ARDS is strongly influenced by specific organ failures (e.g., hepatic and renal failure). The mechanisms by which ARDS and extrapulmonary organ system fail ure interact, however, are poorly delineated. We ad dress three aspects of the multisystemic nature of ARDS. First, we analyze evidence that suggests ARDS is a mul tisystem disorder fron the outset, involving panendothe lial injury mediated by cellular interactions and humoral substances that act similarly at many vascular target sites. Second, we discuss the role of three extrapulmo nary organs in the modulation of ARDS: the liver, the gastrointestinal mucosa, and the kidneys. Third, we ad dress the unifying hypothesis that uncontrolled ongoing inflammation, which is often but not always caused by infection, is the essential link between ARDS and its progression to multiple system organ failure.

Weaning from Mechanical Ventilation

For most patients who require mechanical ventilation weaning and extubation is simple. In these patients a variety of strategies can be successful. In addition, sim ple criteria may predict when the patient is ready for extubation. For the small group of patients who require prolonged mechanical ventilation, however, contro versy exists about how best to remove ventilator sup port by weaning, and available data are sparse. Much of the controversy has centered on T-piece weaning ver sus intermittent mandatory ventilation. To date no con trolled study has demonstrated the superiority of either intermittent mandatory ventilation or T-piece weaning in difficult-to-wean patients. In the evolution of this con troversy, concern has developed over the potential for increased inspiratory work and expiratory resistance that may be associated with certain intermittent manda tory ventilation systems. The possibility that significant inspiratory work may occur during assist-control venti lation has also been demonstrated. Respiratory muscle weakness and fatigue is likely important in failure to wean. Other possible causes are failure of the cardiovas cular system and impaired ability of the lung to carry out gas exchange. In this article we first examine criteria and techniques for weaning short-term ventilator pa tients. We then examine criteria to begin the weaning process in prolonged ventilation patients, potential causes of failure to wean, and techniques that can be used to remove ventilator support from patients who are difficult to wean. Much literature has been devoted to techniques and criteria for weaning and extubation of patients from mechanical ventilation. For most patients who require ventilatory support, weaning and extuba tion can be easily accomplished by a variety of tech niques [1-4]. At one referral center 77.2% of all surviving patients were weaned from the ventilator within 72 hours of the onset of mechanical ventila tion, and 91% were weaned within 7 days [1]. Less than 10% of ventilated patients potentially posed problems in weaning from mechanical ventilation. Similarly, at a community hospital, few surviving patients required prolonged ventilatory support [2]. In easy-to-wean patients, Sahn and Lakshminarayan [5] described simple criteria that are predictive of successful discontinuation of ventilator support. For the small group of patients who require pro longed mechanical ventilation, however, minimal data are available. In these patients criteria to deter mine weaning ability or which measurements to follow are not clearly defined. Furthermore, no controlled trials are available to compare the differ ent weaning techniques proposed. In this article we first address routine weaning of the patient who has not required prolonged ventilator support. We then examine the difficult-to-wean patient and dis cuss criteria to begin the weaning process, poten tial causes of failure to wean, and available weaning techniques.

Nutrition and Nutritional Support in Critically Ill Patients

The use of intravenous nutritional support has increased dramatically in the last 20 years. Although it is not without controversy, administration of nutritional support is common practice in hospitalized patients including critically ill patients. Malnutrition continues to be reported in a significant number of hospitalized patients. The incidence of malnutrition in critically ill patients may be even higher than that reported in hospitalized patients overall. The consequences of malnutrition in a critically ill patient may be severe. Nutritional assessment and nutritional support can present special challenges to the intensivist. Techniques of nutritional assessment in critically ill patients are evaluated. Guidelines for the determination of the nutritional needs of these patients are outlined. Methods of delivery of nutritional support in critically ill patients are reviewed. Complications of nutritional support are discussed.

Experience With Nosocomial Infection in Children Under 5 Treated in an Urban Diarrheal Treatment Center in Bangladesh

We aimed to evaluate the factors associated with nosocomial infections (NIs) in under-5 children and in bacterial isolates from their blood, urine, and stool. We reviewed all under-5 hospitalized children with clinically diagnosed NIs in the inpatient ward at Dhaka Hospital of International Centre for Diarrhoeal Disease Research, Bangladesh, between January and December 2012. Comparison was made among the children with (cases = 71) and without NI (controls = 142). NI was defined as the development of new infection 48 hours after admission. Bacterial isolates in urine, blood, and stool were found in 11/52 (21%), 9/69 (13%), and 2/16 (12%) respectively. In logistic regression analysis, the children with NI were independently associated with severe acute malnutrition, congenital anomaly, invasive diarrhea, urinary tract infection on admission, and use of intravenous cannula during hospitalization. Thus, identification of these simple clinical parameters may help in preventive measures being taken to reduce the rate of NIs in such children.

Reanimación y prevención de las infecciones nosocomiales

Los servicios de reanimación deben organizar de forma minuciosa la prevención de infecciones en sus enfermos, ya que éstos suelen estar inmunodeprimidos, están sometidos a múltiples procedimientos invasivos realizados por un personal sanitario variado, a menudo en situaciones de urgencia y a cualquier hora del día o de la noche. Las principales infecciones que hay que tratar de prevenir son las neumonías bacterianas adquiridas asociadas a ventilación mecánica (NAVM), las infecciones relacionadas con catéteres intravasculares y las infecciones urinarias asociadas al sondeo vesical. La incidencia de estas infecciones ha disminuido en la mayoría de los servicios que realizan un control cifrado, sobre todo gracias a la implantación de programas de mejora de la calidad. Las técnicas de prevención son múltiples y deben aplicarse simultáneamente. Incluyen medidas globales, como las modalidades de prevención de la transmisión cruzada (higiene de las manos, sobre todo) o de uso de antibióticos, concebidas para reducir la presión de selección de bacterias resistentes a éstos, así como medidas específicas relativas a la colocación y uso de cada uno de los dispositivos invasivos. Numerosas técnicas han demostrado su eficacia en estudios de buen nivel metodológico (higiene de las manos, apósitos para catéteres, etc.), mientras que otras siguen siendo objeto de controversias, por lo que las recomendaciones nacionales e internacionales se actualizan regularmente de acuerdo con los nuevos datos científicos. Estas medidas, implantadas de manera razonada en el marco de programas de mejora de la calidad, permiten obtener tasas muy bajas de infecciones relacionadas con el uso de catéteres vasculares y resultados menos satisfactorios con las NAVM, que justifican la necesidad de proseguir la investigación en este campo.

Rianimazione e prevenzione delle infezioni nosocomiali

I servizi di rianimazione devono organizzare la prevenzione delle infezioni nei loro pazienti in modo minuzioso, in quanto i pazienti sono spesso immunodepressi e subiscono gesti invasivi molteplici, realizzati da personale differente, spesso in situazioni di urgenza e a qualsiasi ora del giorno o della notte. Le principali infezioni che bisogna tentare di prevenire sono le polmoniti batteriche acquisite sotto ventilazione meccanica (PAVM), le infezioni su cateteri intravascolari e le infezioni urinarie su catetere vescicale. L’incidenza di queste infezioni è diminuita nella maggior parte dei servizi che ne effettuano un monitoraggio su base numerica, in particolare nel quadro di programmi di miglioramento della qualità. Le tecniche di prevenzione sono molteplici e devono essere applicate simultaneamente. Esse riguardano delle misure globali, come le modalità di prevenzione della trasmissione crociata (igiene delle mani, in particolare) o di utilizzo degli antibiotici nella prospettiva di ridurre la pressione di selezione di batteri resistenti agli antibiotici, così come delle misure specifiche relative al posizionamento e all’utilizzo di ciascuno dei dispositivi invasivi. Numerose tecniche si sono dimostrate efficaci in studi di buon livello metodologico (igiene delle mani, medicazioni dei cateteri, ecc.) mentre altre sono ancora oggetto di controversie, portando a raccomandazioni nazionali e internazionali regolarmente aggiornate in funzione dei nuovi dati scientifici. Queste misure, implementate in modo ragionato nel quadro di programmi di miglioramento della qualità, consentono di ottenere dei tassi molto bassi per quanto riguarda le infezioni dei cateteri vascolari e dei risultati meno buoni per le PAVM, illustrando la necessità di proseguire la ricerca in questo settore.

A review of stress-related mucosal disease

OBJECTIVE

To review and summarize the human and veterinary literature regarding stress-related mucosal disease (SRMD) pathogenesis, patient risk factors, and therapeutic options for prophylaxis and treatment.

ETIOLOGY

SRMD is a common sequela of critical illness in human patients. Development of SRMD results from splanchnic hypoperfusion, reperfusion injury, and exposure of the gastric mucosa to acid, pepsin, and bile acids following breakdown of the gastric mucosal defense system. Human patients with the highest risk of stress ulceration include those with respiratory failure necessitating mechanical ventilation greater than 48 h or coagulopathy. Currently, little is known about the incidence and pathophysiology of SRMD in critically ill veterinary patients.

DIAGNOSIS

A presumptive diagnosis can be made in high-risk patient populations following detection of occult or gross blood in nasogastric tube aspirates, hematemesis, or melena. Definitive diagnosis is achieved via esophagogastroduodenoscopy. Lesions are localized to the acid-producing portions of the stomach, the fundus, and body.

THERAPY

Therapy is aimed at optimization of tissue perfusion and oxygenation. Pharmacologic interventions are instituted to increase intraluminal pH and augment natural gastric defenses. Histamine(2)-receptor antagonists, proton pump inhibitors, and sucralfate are the mainstays of therapy. In people, clinically significant bleeding may necessitate additional interventions (eg, packed red blood cell transfusions, endoscopic, or surgical hemostasis).

PROGNOSIS

Mortality is increased in people with clinically significant bleeding compared to those patients who do not bleed. Institution of prophylaxis is recommended in high-risk patients. However, no consensus exists regarding initiation of prophylaxis, preference of frontline drug class, or indication for discontinuation of therapy. The prognosis of veterinary patients with SRMD remains unknown at this time.

Gastrointestinal prophylaxis in neurocritical care

The aim of this study is to review and summarize the relevant literature regarding pharmacologic and non-pharmacologic methods of prophylaxis against gastrointestinal (GI) stress ulceration, and upper gastrointestinal bleeding in critically ill patients. Stress ulcers are a known complication of a variety of critical illnesses. The literature regarding epidemiology and management of stress ulcers and complications thereof, is vast and mostly encompasses patients in medical and surgical intensive care units. This article aims to extrapolate meaningful data for use with a population of critically ill neurologic and neurosurgical patients in the neurological intensive care unit setting. Studies were identified from the Cochrane Central Register of controlled trials and NLM PubMed for English articles dealing with an adult population. We also scanned bibliographies of relevant studies. The results show that H(2)A, sucralfate, and PPI all reduce the incidence of UGIB in neurocritically ill patients, but H(2)A blockers may cause encephalopathy and interact with anticonvulsant drugs, and have been associated with higher rates of nosocomial pneumonias, but causation remains unproven and controversial. For these reasons, we advocate against routine use of H(2)A for GI prophylaxis in neurocritical patients. There is a paucity of high-level evidence studies that apply to the neurocritical care population. From this study, it is concluded that stress ulcer prophylaxis among critically ill neurologic and neurosurgical patients is important in preventing ulcer-related GI hemorrhage that contributes to both morbidity and mortality. Further, prospective trials are needed to elucidate which methods of prophylaxis are most appropriate and efficacious for specific illnesses in this population.

Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality, with mortality rates approaching 62%. HAP and VAP are the second most common cause of nosocomial infection overall, but are the most common cause documented in the intensive care unit setting. In addition, HAP and VAP produce the highest mortality associated with nosocomial infection. As a result, evidence-based guidelines were prepared detailing the epidemiology, microbial etiology, risk factors and clinical manifestations of HAP and VAP. Furthermore, an approach based on the available data, expert opinion and current practice for the provision of care within the Canadian health care system was used to determine risk stratification schemas to enable appropriate diagnosis, antimicrobial management and nonantimicrobial management of HAP and VAP. Finally, prevention and risk-reduction strategies to reduce the risk of acquiring these infections were collated. Future initiatives to enhance more rapid diagnosis and to effect better treatment for resistant pathogens are necessary to reduce morbidity and improve survival.

Gastric pH and motility in a porcine model of acute lung injury using a wireless motility capsule

BACKGROUND

Evaluation of gastric pH and motility in a porcine model of acute lung injury using a novel, wireless motility capsule.

MATERIAL/METHODS

A motility capsule was applied into the stomach of 7 Pietrain pigs with acute lung injury induced by high volume saline lavage. Wireless transmission of pH, pressure and temperature data was performed by a recorder attached to the animal's abdomen. Gastric motility was evaluated using pH and pressure values, and capsule location was confirmed by autopsy.

RESULTS

Gastric pH values were statistically significantly different (P<0.003) in the animals over time and ranged from 1.15 to 9.94 [5.73 ± 0.47 (mean ± SD)] with an interquartile range of 0.11 to 2.07. The capsule pressure recordings ranged from 2 to 4 mmHg [2.6 ± 0.5 mmHg (mean ± SD)]. There was no change in pressure patterns or sudden rise of pH >3 pH units during 24 hours. All animals had a gastroparesis with the capsules located in the stomach as indicated by the pressure and pH data and confirmed by necropsy.

CONCLUSIONS

The preliminary data show that Pietrain pigs with acute lung injury have a high variability in gastric pH and severely disturbed gastric motility.

Reduction in the incidence of poststroke nosocomial pneumonia by using the "turn-mob" program

BACKGROUND

One of the most common complications in patients with acute ischemic stroke (AIS) is pneumonia, a complication that has an impact on the patient's survival. The purpose of this study was to establish whether the implementation of a passive turning and mobilization program can prevent the occurrence of nosocomial pneumonia (NP) in patients with AIS.

METHODS

We conducted a randomized clinical trial. Patients diagnosed with AIS within the last 48 hours and without mechanical ventilation were included. Group A was the "turn-mob" program: turning and passive mobilization carried out by a previously trained relative. Group B was the control group: standard treatment characterized by turning carried out by the nursing staff. The purpose was to demonstrate whether the implementation of a manual turning and passive mobilization program could reduce the incidence of NP in patients with AIS during their stay at the hospital and up to 14 days after discharge.

RESULTS

In all, 223 patients were included (group A, n = 111; group B, n = 112). Fourteen (12.6%) patients in group A and 30 (26.8%) in group B developed NP. The implementation of the turn-mob program was associated with a decrease in NP, with a relative risk of 0.39 (95% confidence interval .19-.79; P = .008).

CONCLUSION

The turn-mob program applied on patients during the acute phase of an ischemic stroke decreases the incidence of NP.

To return or to discard? Randomised trial on gastric residual volume management

BACKGROUND

The control of gastric residual volume (GRV) is a common nursing intervention in intensive care; however the literature shows a wide variation in clinical practice regarding the management of GRV, potentially affecting patients' clinical outcomes. The aim of this study is to determine the effect of returning or discarding GRV, on gastric emptying delays and feeding, electrolyte and comfort outcomes in critically ill patients.

METHOD

A randomised, prospective, clinical trial design was used to study 125 critically ill patients, assigned to the return or the discard group. Main outcome measure was delayed gastric emptying. Feeding outcomes were determined measuring intolerance indicators, feeding delays and feeding potential complications. Fluid and electrolyte measures included serum potassium, glycaemia control and fluid balance. Discomfort was identified by significant changes in vital signs.

RESULTS

Patients in both groups presented similar mean GRV with no significant differences found (p=0.111), but participants in the intervention arm showed a lower incidence and severity of delayed gastric emptying episodes (p=0.001). No significant differences were found for the rest of outcome measurements, except for hyperglycaemia.

CONCLUSIONS

The results of this study support the recommendation to reintroduce gastric content aspirated to improve GRV management without increasing the risk for potential complications.

Neumopatías hospitalarias en pacientes con ventilación mecánica

Las neumopatías son la primera causa de infección hospitalaria en reanimación. Las neumopatías hospitalarias en los pacientes con ventilación mecánica (NHPVM) ocurren después de al menos 48 horas de ventilación mecánica invasiva. Su mecanismo es multifactorial, pero la opinión predominante es que obedecen a una inhalación posterior a la colonización orofaríngea, gástrica o traqueal. El retraso en la manifestación permite clasificar las NHPVM en precoces o tardías según se desarrollen antes o después del 5.° día de ventilación mecánica. La clínica puede ayudar al diagnóstico, sobre todo mediante la CPIS (Clinical Pulmonary Infection Score) y también es útil el lavado broncoalveolar (LBA), que parece la mejor prueba para el diagnóstico microbiológico. El diagnóstico diferencial se plantea con una neumopatía no bacteriana o incluso no infecciosa (neoplásica, inflamatoria, fibrosante) en la que siempre debe plantearse la búsqueda de otro foco infeccioso en función de la orientación clínica inicial o del fracaso de la antibioticoterapia. El uso preferente de la ventilación no invasiva, cuando es posible, parece que ayuda a prevenir el desarrollo de la neumopatía hospitalaria. La posición inclinada 30-45° del paciente es la única medida preventiva verdaderamente validada en las NHPVM. El tratamiento curativo de las neumopatías bacterianas descansa por lo general en un tratamiento antibiótico doble, que puede orientarse por los datos de muestras obtenidas con métodos no invasivos como las aspiraciones traqueales efectuadas de forma periódica y sistemática. La duración del tratamiento es discutible, pero los últimos datos apoyan un tratamiento con antibióticos relativamente corto, de 8 días.

Polmoniti nosocomiali acquisite sotto ventilazione meccanica

Le polmoniti sono la prima causa di infezione nosocomiale in rianimazione. Le polmoniti nosocomiali acquisite sotto ventilazione meccanica (PNAVM) compaiono dopo almeno 48 ore di ventilazione meccanica invasiva. Il loro meccanismo è multifattoriale, ma predomina la nozione di inalazione che compare dopo una colonizzazione orofaringea, gastrica o tracheale. Il tempo di comparsa permette di classificare queste PNAVM come precoci o tardive a seconda che compaiano prima o dopo il 5° giorno di ventilazione meccanica. La diagnosi può essere aiutata dalla clinica, essenzialmente grazie al punteggio CPIS (Clinical Pulmonary Infection Score), e dal lavaggio broncoalveolare (BAL), che sembra l’esame più utile per la diagnosi microbiologica. La diagnosi differenziale con una pneumopatia non batterica o anche non infettiva (neoplastica, infiammatoria, fibrotica) o la ricerca di un altro focolaio infettivo devono sempre essere discusse in funzione dell’orientamento clinico iniziale o del fallimento della terapia antibiotica. Il ricorso preferenziale alla ventilazione non invasiva, quando possibile, sembra utile per prevenire l’insorgenza di una pneumopatia nosocomiale. La posizione semiseduta del paziente a 30–45° è la sola misura profilattica veramente validata di prevenzione delle PNAVM. Il trattamento curativo delle polmoniti batteriche si basa in genere su una doppia terapia antibiotica. Quest’ultima può essere orientata dai dati di prelievi non invasivi, come le aspirazioni tracheali, realizzate in modo periodico e sistematico. La durata del trattamento è discussa, ma gli ultimi dati sono in favore di una terapia antibiotica relativamente breve, di 8 giorni.

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.

Risk of aspiration in patients on enteral nutrition: frequency, relevance, relation to pneumonia, risk factors, and strategies for risk reduction

Upper digestive feeding intolerance, as evidenced by high gastric residual volume and vomiting, is the most common complication among hospitalized patients receiving enteral nutrition. These patients are at high risk of developing aspiration pneumonia, which in turn is associated with prolonged hospital stay and increased mortality. Most episodes of aspiration are small in volume and do not lead to pneumonia. The likelihood of pneumonia increases with multiple aspirations. Pneumonia is also more common in critically ill patients who have bacterial colonization of the oropharynx. Gastric residual volume is commonly used as a means to assess aspiration risk during tube feeding. However, recent studies have demonstrated that this measurement has limited sensitivity. The approach to minimizing the frequency of aspiration during tube feeding involves assessment of the patient's degree of risk and initiation of appropriate measures directed at risk reduction.

[Measurement of residual gastric volume: in search of better evidence]

INTRODUCTION

Measurement of residual gastric volume is a frequent practice in chronic patients, but there is lack of consensus on the convenience of reintroducing or discarding aspirated gastric content (AGC).

OBJECTIVE

Determine the grade of scientific evidence on the efficacy of two interventions -reintroduction/rejection- of AGC in chronic patients.

MATERIAL AND METHODS

Systematic review of the evidence available on the convenience of reintroducing or discarding ACG.

PROCEDURE

a) establishment of inclusion/exclusion criteria; b) determination of the search strategy (keywords and itineraries); c) dumping of databases: MEDLINE, CINAHL, CUIDEN, IME, SCIELO and COCHRANE. Search for indirect method and manual dumping of indexes; d) independent and contrasted critical reading, using the CASPe template; and e) contrast of critical analysis results.

RESULTS

Search itineraries generate more than 800 references that once purged make it possible to select 54. After reading them, only 4 really focused on the questions related with the reintroduction/rejection of AGC: 2 revisions, 1 observational study and a random clinical trial with a small sample. Meta-analysis techniques could not be used due to the heterogeneity of these studies. Thus, the results of the study were analyzed separately. Using this procedure, a final result was obtained that showed a low grade of scientific evidence.

CONCLUSIONS

There is limited scientific evidence on the convenience, safety and benefits of both interventions. It is difficult to establish a care protocol, so that we suggest performing an experimental study to establish the indications and contraindications of both interventions.

Comparative study on the effect of enteral feeding on blood glucose

Stress hyperglycaemia is common in intensive care patients. There is recent evidence to suggest that maintaining the blood glucose of a patient in intensive care between 4 mmol/litre and 6.1 mmol/litre reduces morbidity and mortality. The aim of this comparative study was to determine if blood glucose control improves with abolishing feeding breaks and introducing continuous enteral feeding. Twenty ventilated patients admitted to a combined medical and surgical intensive care unit were sampled. Ten patients received standard care (enteral feeding for 18 hours with an 8-hour break). The interventional group received continuous enteral feeding over the 24 hours. Analysis of the data revealed that continuous enteral feeding reduced blood glucose levels significantly, improved blood glucose control and reduced insulin requirements. Research should continue to determine if the results of this study could be replicated within a larger group of intensive care patients.

Critical care nutrition: getting involved as a gastrointestinal endoscopist

The route, timing, and volume of enteral feeding delivered to a patient in the intensive care unit have a profound effect on clinical outcome. At the height of critical illness, problems with ileus, aspiration, and the systemic inflammatory response syndrome make the provision of enteral nutrients a difficult and somewhat risky endeavor. The gastrointestinal endoscopist has the technical skills to place feeding tubes deep within the jejunum and an underlying expertise in gut physiology to monitor patients effectively once feeds are initiated. Attention to detail in the techniques for attaining enteral access, early identification of potential problems, and quick institution of simple endoscopic strategies help improve delivery of nutrition support, minimize the likelihood for in-hospital complications, and optimize patient outcome.

Ventilator associated pneumonia and infection control

Ventilator associated pneumonia (VAP) is the leading cause of morbidity and mortality in intensive care units. The incidence of VAP varies from 7% to 70% in different studies and the mortality rates are 20-75% according to the study population. Aspiration of colonized pathogenic microorganisms on the oropharynx and gastrointestinal tract is the main route for the development of VAP. On the other hand, the major risk factor for VAP is intubation and the duration of mechanical ventilation. Diagnosis remains difficult, and studies showed the importance of early initiation of appropriate antibiotic for prognosis. VAP causes extra length of stay in hospital and intensive care units and increases hospital cost. Consequently, infection control policies are more rational and will save money.

Pre-pyloric versus post-pyloric feeding

Optimal management of the critically ill patient involves the initiation and rapid advancement of early enteral nutrition (EN). Compared to parenteral nutrition or no nutritional support, early enteral feeding favorably impacts patient outcome by reducing infectious morbidity and shortening hospital length of stay. Controversy exists over the true risks and benefits of pre-pyloric versus post-pyloric feeding. Placement of nasogastric tubes is easier than nasojejunal tubes, initiation of EN is more expedient, and intragastric feeds may provide greater physiologic benefits. Post-pyloric feeding, on the other hand, is associated with fewer interruptions once EN has been started, may reach goal calorie provision sooner, and may reduce risk for gastroesophageal reflux and aspiration. Overall differences in outcome between the two methods of feeding, however, are minimal. Thus, the final choice for the practicing clinician on the level of infusion of enteral feeding is based on institutional factors (related to protocols and available expertise) and the degree of risk and potential tolerance of the individual patient.

The role of endoscopically placed feeding or decompression tubes

The minimally invasive nature of endoscopically placed gastrostomy tubes makes them a viable consideration in palliative care. Complications related to the procedure appear to correlate with age and underlying comorbidities.However, in many instances, the scientific basis for establishing benefit or harm from tube placement is methodologically inadequate. Decisions must be preceded by a discussion of the value and potential risk of artificial nutrition in a particular setting, respecting the wishes and beliefs of each patient and his or her family. The decision to use PEG placement for any reason should be consistent with legal and ethical principles, reflect patient autonomy over any other consideration (including beneficence), and arise from a clear determination of the goals of care (and whether the PEG placement will truly help meet those goals). Whenever possible, further studies with better design are needed to evaluate whether the use of PEG truly affects quality of life and patient outcome in palliative care. PEG tubes for decompression are placed successfully most of the time. Symptom relief occurs usually within 7 days of the procedure. Overall, the morbidity related to the PEG procedure for decompression is only slightly higher than when the same technique is used for nutritional purposes. The appropriate timing for PEG tube placement for nutritional support and for decompression throughout the course of disease progression may be difficult to determine and yet may be a factor in its overall efficiency. Only minor modifications of the basic technique used for PEG placement for nutritional purposes are required to adapt the technique to a variety of other applications in palliative care.

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.

Ventilator-associated pneumonia using a closed versus an open tracheal suction system

OBJECTIVE

The aim of this study was to analyze the prevalence of ventilator-associated pneumonia (VAP) using a closed-tracheal suction system vs. an open system.

DESIGN

Prospective and randomized study, from October 1, 2002, to December 31, 2003.

SETTING

A 24-bed medical-surgical intensive care unit in a 650-bed tertiary hospital.

PATIENTS

Patients requiring mechanical ventilation for >24 hrs.

INTERVENTIONS

Patients were randomized into two groups; one group was suctioned with the closed-tracheal suctioning system and another group with the open system.

MEASUREMENTS

Throat swabs were taken at admission and twice a week until discharge to classify pneumonia in endogenous and exogenous.

MAIN RESULTS

A total of 443 patients (210 with closed-tracheal suction system and 233 with the open system) were included. There were no significant differences between groups of patients in age, sex, diagnosis groups, mortality, number of aspirations per day, and Acute Physiology and Chronic Health Evaluation II score. No significant differences were found in either the percentage of patients who developed VAP (20.47% vs. 18.02%) or in the number of VAP cases per 1000 mechanical ventilation-days (17.59 vs. 15.84). There were also no differences in the VAP incidence by mechanical ventilation duration. At the same time, we did not find any differences in the incidence of exogenous VAP. Likewise, there were also no differences in the microorganisms responsible for pneumonia. Patient cost per day for the closed suction was more expensive than the open suction system (11.11 US dollars +/- 2.25 US dollars vs. 2.50 US dollars +/- 1.12 US dollars, p < .001).

CONCLUSION

We conclude that in our study, the closed-tracheal suction system did not reduce VAP incidence, even for exogenous pneumonia.

Validation of the Canadian clinical practice guidelines for nutrition support in mechanically ventilated, critically ill adult patients: Results of a prospective observational study*

OBJECTIVE

Recently, evidence-based clinical practice guidelines for the provision of nutrition support in the critical care setting have been developed. To validate these guidelines, we hypothesized that intensive care units whose practice, on average, was more consistent with the guidelines would have greater success in providing enteral nutrition.

DESIGN

Prospective observational study.

SETTING

Fifty-nine intensive care units across Canada.

PATIENTS

Consecutive cohort of mechanically ventilated patients.

INTERVENTIONS

In May 2003, participating intensive care units recorded nutrition support practices on a consecutive cohort of mechanically ventilated patients who stayed for a minimum of 72 hrs. Sites enrolled an average of 10.8 (range, 4-18) patients for a total of 638. Patients were observed for an average of 10.7 days.

MEASUREMENTS AND MAIN RESULTS

We examined the association between five recommendations from the clinical practice guidelines most directly related to the provision of nutrition support (use of parenteral nutrition, feeding protocol, early enteral nutrition, small bowel feedings, and motility agents) and adequacy of enteral nutrition. We defined adequacy of enteral nutrition as the percent of prescribed calories that patients actually received. Across sites, the average adequacy of enteral nutrition over the observed stay in intensive care unit ranged from 1.8% to 76.6% (average 43.0%). Intensive care units with a greater than median utilization of parenteral nutrition (>17.5% patient days) had a much lower adequacy of enteral nutrition (32.9 vs. 52.7%, p < .0001). Intensive care units that used a feeding protocol tended to have a higher adequacy of enteral nutrition than those that did not (44.9 vs. 38.5%, p = .03). Intensive care units that initiated enteral nutrition on >50% of their patients within the first 48 hrs had a higher adequacy of enteral nutrition than those that did not (48.1 vs. 34.4%, p < .0001). Intensive care units that had a >50% utilization of motility agents and/or any small bowel feedings in patients with high gastric residuals tended to have a higher adequacy of enteral nutrition than those intensive care units that did not (45.6 vs. 39.2%, p = .04, and 48.4 vs. 41.8%, p = .16, respectively).

CONCLUSIONS

Intensive care units that were more consistent with the Canadian clinical practice guidelines were more likely to successfully feed patients via enteral nutrition. Adoption of the Canadian clinical practice guidelines should lead to improved nutrition support practice in intensive care units. This may translate into better outcomes for critically ill patients receiving nutrition support.

Stress-related mucosal disease: risk factors and prophylactic therapy

BACKGROUND

The term stress-related mucosal disease (SRMD) represents a continuum of conditions ranging from stress-related injury (superficial mucosal damage) to stress ulcers (focal deep mucosal damage). Caused by mucosal ischemia, SRMD is most commonly seen in critically ill patients in the intensive care unit (ICU). Prophylaxis of stress ulcers may reduce major bleeding but has not yet been shown to improve survival.

OBJECTIVES

This article reviews currently available agents for the prophylaxis of SRMD and discusses their uses and potential adverse effects.

METHODS

Relevant articles in the English-language literature were identified through a MEDLINE search (1968-2003) using the key words stress-related mucosal disease, stress-related injury, ulcer, prophylaxis, intensive care unit, and upper gastrointestinal bleeding.

RESULTS

The most widely used drugs for stress-related injury are the intravenous histamine(2)-receptor antagonists. These drugs raise gastric pH but are associated with the development of tolerance and possible drug interactions and neurologic manifestations. Sucralfate, which can be administered by the nasogastric route, can protect the gastric mucosa without raising pH, but may decrease the absorption of concomitantly administered oral medications. The prostaglandin misoprostol has not been shown to be of benefit in the prophylaxis of SRMD. Antacids lower the risk of gastrointestinal bleeding, but large volumes of antacids are required and treatment is labor intensive. Proton pump inhibitors (PPIs) are the most potent acid-suppressive pharmacologic agents available. Esomeprazole, lansoprazole, omeprazole, pantoprazole, and rabeprazole substantially raise gastric pH for up to 24 hours after a single dose. The availability of an intravenous formulation of pantoprazole may help improve the treatment of SRMD in ICU patients, particularly those receiving mechanical ventilation. Tolerance does not develop, and few adverse effects have been reported.

CONCLUSIONS

Recent studies of PPIs have shown promising results in high-risk patients, making this class of drugs an option for the prophylaxis of SRMD.

Radiology in the intensive care unit (Part I)

The increasing complexity of the intensive care patient combined with the recent advances in imaging technology has generated a new perspective on intensive care radiology. The purpose of this 2-part review article is to describe the contribution of radiology to the management of these critically ill patients. The first article will discuss the impact of picture archiving and communication system (PACS) on critical care management and utility of the portable chest radiograph in the detection and evaluation of pulmonary disease with correlation to computed tomography (CT). The second article describes in more detail the increasing role of CT in diagnosis and therapeutic procedures. In particular, the implementation of CT pulmonary angiography in the evaluation of pulmonary emboli and the introduction of the new multislice detector CT scanners that allow even the most dyspneic patient to be evaluated. Pleural complications in the intensive care unit and image-guided intervention will also be discussed.

Nosocomial pneumonia in the intensive care unit: controversies and dilemmas

Nosocomial pneumonia (NP), and its most serious form, ventilator-associated pneumonia (VAP), is a major cause of morbidity and mortality in the ICU. Numerous controversies exist, from diagnostic criteria to prevention and treatment, including the issues of attributable mortality of VAP, differences in the approach to early and late VAP, and the best diagnostic methods. Initial, accurate therapy is one of the most important factors determining outcome in VAP. Antibiotic monotherapy versus combination therapy is not clearly defined, as clinicians struggle with the dual risk of inadequate therapy negatively affecting outcome and overtreatment promoting antibiotic resistance. The role of airway and gastrointestinal colonization and innovative preventive strategies such as noninvasive ventilation, antibiotic rotation, and aerosolized antibiotics are discussed. No uniform standards exist for the approach to VAP. The authors highlight the major controversies and dilemmas in the clinical approach to VAP, with recommendations for the bedside management of these patients.

Risk factors for ventilator-associated pneumonia: from epidemiology to patient management

Risk factors for the development of ventilator-associated pneumonia (VAP), as identified in epidemiological studies, have provided a basis for testable interventions in randomized trials. We describe how these results have influenced patient treatment. Single interventions in patients undergoing intubation have focused on either reducing aspiration of oropharyngeal secretions, modulation of colonization (in either the oropharynx, the stomach, or the whole digestive tract), use of systemic antimicrobial prophylaxis, or ventilator circuit changes. More recently, multiple simultaneously implemented interventions have been used. In general, routine measures to decrease oropharyngeal aspiration and antibiotic-containing prevention strategies appear to be the most effective, and the latter were associated with improved rates of patient survival in recent trials. These benefits must be balanced against the widespread fear of emergence of antibiotic resistance. In hospital settings with low baseline levels of antibiotic resistance, however, the benefits to patient outcome may outweigh this fear of resistance. In settings with high levels of antibiotic resistance, combined approaches of non-antibiotic using strategies and education programs might be most beneficial.

Prevention of hospital-acquired pneumonia:

Several preventive measures for VAP have been empirically tested. There is clear evidence that antibiotic-containing preventive strategies, such as SDD and oropharyngeal decontamination, are very effective in different patient populations. Selection of antibiotic resistance remains the major disadvantage of these strategies, however, limiting its applicability in settings with high levels of antibiotic resistance. This probably precludes the use of these strategies in many American settings, but may allow their use in European countries with much lower endemic levels of resistance. There is little evidence that systemic prophylaxis is effective for the prevention of VAP, and initial studies were associated with resistance problems. Of the non antibiotic-containing preventive strategies, subglottic aspiration was effective in several studies, whereas other strategies, such as immunonutrition with glutamine or the semirecumbent patient position, were effective in single studies. All these studies were executed in European ICUs. For these interventions, more data are needed on the generalizability, feasibility, and cost effectiveness. Few data support the use of sucralfate for stress ulcer prophylaxis and modulation of enteral nutrition practices as preventive measures for VAP.

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.