Manual ventilation bags as a source for bacterial colonization of intubated patients

Applying Adult Ventilator-associated Pneumonia Bundle Evidence to the Ventilated Neonate

BACKGROUND

Ventilator-associated pneumonia (VAP) in neonates can be reduced by implementing preventive care practices. Implementation of a group, or bundle, of evidence-based practices that improve processes of care has been shown to be cost-effective and to have better outcomes than implementation of individual single practices.

PURPOSE

The purpose of this article is to describe a safe, effective, and efficient neonatal VAP prevention protocol developed for caregivers in the neonatal intensive care unit (NICU). Improved understanding of VAP causes, effects of care practices, and rationale for interventions can help reduce VAP risk to neonatal patients.

METHOD

In order to improve care practices to affect VAP rates, initial and annual education occurred on improved protocol components after surveying staff practices and auditing documentation compliance.

FINDINGS/RESULTS

In 2009, a tertiary care level III NICU in the Midwestern United States had 14 VAP cases. Lacking evidence-based VAP prevention practices for neonates, effective adult strategies were modified to meet the complex needs of the ventilated neonate. A protocol was developed over time and resulted in an annual decrease in VAP until rates were zero for 20 consecutive months from October 2012 to May 2014.

IMPLICATIONS FOR PRACTICE

This article describes a VAP prevention protocol developed to address care practices surrounding hand hygiene, intubation, feeding, suctioning, positioning, oral care, and respiratory equipment in the NICU.

IMPLICATIONS FOR RESEARCH

Implementation of this VAP prevention protocol in other facilities with appropriate monitoring and tracking would provide broader support for standardization of care. Individual components of this VAP protocol could be studied to strengthen the inclusion of each; however, bundled interventions are often considered stronger when implemented as a whole.

Infection Prevention and Control Guideline for Cystic Fibrosis: 2013 Update

The 2013 Infection Prevention and Control (IP&C) Guideline for Cystic Fibrosis (CF) was commissioned by the CF Foundation as an update of the 2003 Infection Control Guideline for CF. During the past decade, new knowledge and new challenges provided the following rationale to develop updated IP&C strategies for this unique population:

1.The need to integrate relevant recommendations from evidence-based guidelines published since 2003 into IP&C practices for CF. These included guidelines from the Centers for Disease Control and Prevention (CDC)/Healthcare Infection Control Practices Advisory Committee (HICPAC), the World Health Organization (WHO), and key professional societies, including the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA). During the past decade, new evidence has led to a renewed emphasis on source containment of potential pathogens and the role played by the contaminated healthcare environment in the transmission of infectious agents. Furthermore, an increased understanding of the importance of the application of implementation science, monitoring adherence, and feedback principles has been shown to increase the effectiveness of IP&C guideline recommendations.

2.Experience with emerging pathogens in the non-CF population has expanded our understanding of droplet transmission of respiratory pathogens and can inform IP&C strategies for CF. These pathogens include severe acute respiratory syndrome coronavirus and the 2009 influenza A H1N1. Lessons learned about preventing transmission of methicillin-resistantStaphylococcus aureus(MRSA) and multidrug-resistant gram-negative pathogens in non-CF patient populations also can inform IP&C strategies for CF.

The changing microbial epidemiology in cystic fibrosis

Infection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.

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

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

[Pathogenesis and environmental factors in ventilator-associated pneumonia]

Respiratory infections in intubated patients can derive from endogenous or exogenous sources. The major route for acquiring endemic ventilator-associated pneumonia (VAP) is oropharyngeal colonization by endogenous flora and leakage of contaminated secretions into the lower respiratory tract. However, a not inconsiderable percentage of VAP results from exogenous nosocomial colonization, especially pneumonias caused by resistant bacteria such as methicillin-resistant Staphylococcus aureus and multiresistant Acinetobacter baumannii or Pseudomonas aeruginosa, as well as by Legionella spp or filamentous fungi, such as Aspergillus. This article reviews the pathogenesis of VAP and the role of the intensive care environment as a source of pathogenic microorganisms.

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

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

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

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

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

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

Bacterial/viral filtration: let the breather beware!

Most clinicians believe that any device that is marketed as a "bacterial/viral filter" must necessarily be capable of capturing any individual bacteria or viruses that might be suspended within inhaled or exhaled gases. We were surprised to discover that this is, by no means, a justifiable assumption. This article describes testing methods that manufacturers employ to generate the often-misleading efficiency specifications that are claimed for some of these devices. We discuss articles that have documented the presence of airborne pathogens in the effluent of a ventilator circuit, and characterize the attributes that a competent filter must exhibit if it is to succeed in protecting patients and caregivers from incidental exposure to bacteria, viruses, aerosolized drugs, and endotoxins. This article continues with a discussion of the numbers of particles that are commonly produced with commercially available pneumatic nebulizers, the comparative performance characteristics of filters and heat/moisture exchanging filters (HMEFs), and the success or failure of various brands of HMEFs to comply with the guidelines recently developed by the Centers for Disease Control and Prevention for the management of patients who are harboring active tuberculosis. The presentation concludes with a description of the standards that apply to any filter that classifies as a high-efficiency particulate aerosol (HEPA) device, and demonstrates that the performance of filters/HMEFs in common clinical use can range from approximately 1/50th to > 30-fold the efficiency of a HEPA-grade device. Those who frequent the bedside of patients receiving ventilation might unwittingly be placing themselves at considerable risk of exposure to infectious microaerosols, but methods are available to dramatically decrease those risks.

Tracheostomy management in the chronically ventilated patient

Tracheotomy is a fundamentally important technique for managing patients who require long-term mechanical ventilation. Appropriate application of tracheotomy requires a skilled approach for timing the procedure, selecting the appropriate tracheostomy tube appliance, caring for the artificial airway once it is in place, and assisting patients with their specialized needs, such as articulated speech, airway humidification, and oral nutrition. Preparing patients for airway decannulation after they have weaned from mechanical ventilation requires a similar level of skill and attention to detail.

Nosocomial pneumonia. Diagnosis and prevention

Ventilator-associated pneumonia (VAP) is an important complication in patients with respiratory failure who undergo endotracheal intubation and mechanical ventilation. VAP cannot be accurately diagnosed by clinical or radiographic criteria or culture of endotracheal aspirates; however, it can be accurately diagnosed by histopathologic examination of lung tissue, rapid cavitation of a pulmonary infiltrate, culture of empyema fluid, percutaneous lung needle aspiration, simultaneous recovery of the same microorganism from cultures of respiratory secretions, and blood and quantitative culture of lower respiratory tract secretions obtained by bronchoscopy. VAP can be prevented by proper decontamination and use of ventilatory support equipment, practice of proper nursing techniques during care of the mechanically ventilated patient, and use of face mask ventilation in selected patients.

Is it safe to use preprepared endotracheal tubes in the resuscitation room?

OBJECTIVE

To investigate the bacteriological safety of preprepared endotracheal tubes in accident and emergency departments.

METHODS

Swabs were taken and cultured from luminal and exterior surfaces of every preprepared exposed endotracheal tube in a hospital resuscitation room.

RESULTS

Coagulase negative staphylococci (common skin commensals) were isolated from 50% of the tubes. No other bacteria were isolated.

CONCLUSIONS

The practice of leaving preprepared airway equipment exposed in the resuscitation room is unlikely to contribute to the development of nosocomial pneumonia, provided the equipment is kept dry and that personnel minimize handling.

Burkholderia cepacia respiratory tract acquisition: epidemiology and molecular characterization of a large nosocomial outbreak

In 1994 we investigated a large outbreak of Burkholderia (formerly Pseudomonas) cepacia respiratory tract acquisition. A case patient was defined as any patient with at least one sputum culture from which B. cepacia was isolated from 1 January to 31 December 1994. Seventy cases were identified. Most (40 [61%]) occurred between 1 February and 31 March 1994; of these, 35 (86%) were mechanically ventilated patients, 30 of whom were in an intensive-care unit (ICU) when B. cepacia was first isolated. Compared with control patients who were mechanically ventilated in an ICU, these 30 case-patients were significantly more likely to have been ventilated for 2 or more days (30/30 v. 15/30; P < 0.001) or to have been intubated more than once (12/30 v. 2/30; OR = 9.3, 95% CI 1.6-68.8; P = 0.002) before the first isolation of B. cepacia. By multivariate analysis, the 35 mechanically ventilated case-patients were significantly more likely to have received a nebulized medication (OR = 11.9, 95% CI = 1.6-553.1; P < 0.001) and a cephalosporin antimicrobial (OR = 11.9, 95% CI = 1.6-553.1) in the 10 days before the first isolation of B. cepacia, compared with B. cepacia-negative control-patients matched by date and duration of most recent mechanical ventilation. Although B. cepacia was not cultured from medications or the hospital environment, all outbreak strains tested had an identical DNA restriction endonuclease digestion pattern by pulsed-field gel electrophoresis. Review of respiratory therapy procedures revealed opportunities for contamination of nebulizer reservoirs. This investigation suggests that careful adherence to standard procedures for administration of nebulized medications is essential to prevent nosocomial respiratory infections.

Colonization of mechanical ventilation bags during use

BACKGROUND

Colonization of patients' mechanical ventilation bags was examined to evaluate two criteria (days in use and appearance) for replacing the disposable adapter that interfaces with the patient.

METHODS

Adapters used 1 to 2, 3 to 4 and 6 to 7 days formed groups I, II, and III, respectively (n = 29 to 67 per group). Another group (IA) contained 33 adapters used 1 to 2 days from patients intubated at least 7 days. Appearance of adapters was noted and adapters were swab cultured on nonselective medium.

RESULTS

Analysis of variance indicated a difference in log colony-forming units per adapter between groups I and II (p = 0.032), but colony-forming units per adapter varied widely. Group III had a lower mean colony-forming unit count than group II. Groups I and II differed in variables other than days of use, but these confounding variables were eliminated by substituting group IA for group I. When adapter appearance versus colonization was examined by chi 2 test, a significant difference was found between adapters that looked "clean" and those with precipitate or with mucus or blood.

CONCLUSIONS

For the subjects studied, colonization of adapters increased significantly between 1 to 2 and 3 to 4 days of use but varied widely. Appearance may be more useful than days in use as a criterion for changing adapters.

Emergency management of the airway outside the operating room

Successful emergency airway intervention incorporates the anaesthetist's basic skills in airway management with the knowledge of the special nature of the clinical problems that arise outside the operating room. While a thorough but rapid evaluation of the key anatomical and physiological factors of an individual patient may result in an obvious choice for optimal management, clinical problems often arise in which there is not an evident "best approach." In these less clear-cut situations, the anaesthetist may do well to employ those techniques with which she/he has the greatest skills and experience. At times, however, some degree of creative improvisation is required to care for an especially difficult problem.