Summer 2014 Neonatal Pediatrics Bulletin

Notes from the Chair

Natalie Napolitano, MPH, RRT-NPS, FAARC

I hope everyone is enjoying the summer and has been able to take some great vacations. As you read this issue of the Bulletin, we will be preparing for AARC Congress 2014 in Las Vegas, Dec. 9-12. There are many pediatric-specific symposiums and lectures planned for this year, and again, a large number of abstracts submitted for consideration. It is shaping up to be another great neo/peds showing!

In this Bulletin we provide some information on the B. Cepacia outbreak that has been occurring at several children’s hospitals across the country, so that we will all be better aware of the situation. As more information comes out of the CDC’s investigation I will keep the section updated. We also have an informative article on recruitment maneuvers and how to best implement them in our patients.

As always we are looking for topics for future Bulletin articles, as well as section members willing to write those articles. Please send any ideas you may have to myself, Lisa, or Jenni.

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Containing the B. Cepecia Outbreak

Natasha Lavin, BS, RRT-NPS, CPFT,
Nancy Craig, BS, RRT-NPS,
and Rita Giordano, RRT-NPS,
Children’s Hospital of Philadelphia, Philadelphia, PA

Burkholderia Cepacia, or B. Cepacia, is an opportunistic pathogen commonly known for causing respiratory colonization and infection, and increasing mortality and morbidity rates, in patients with cystic fibrosis (CF).1 The health care setting has introduced an additional patient population, with a number of reported outbreaks of B. Cepacia in the non-CF population as well.

This gram negative bacillus is not considered part of a human’s normal flora.2 B. Cepacia is commonly found in moist environments such as intravenous fluids, nebulizer solutions, and medical devices. In addition, B. Cepacia contamination can be found in pharmaceuticals, cosmetics, and disinfecting solutions.2 The following paragraphs provide some insight on how B. Cepacia can cause hospital outbreaks from typically used hospital supplies.

Martin and colleagues described their experience with an outbreak of B. Cepacia over the course of four months in a tertiary care teaching hospital in Germany.3 No patients studied had medical conditions usually associated with B. Cepacia infection, such as CF. After investigation it was discovered that prefabricated moist washcloths could be the potential source. Twelve different packages were analyzed, of which ten showed evidence of bacterial growth, nine with B. Cepacia. Following the investigation the prefabricated cloths were eliminated from the institution.

In another documented outbreak in ventilated patients, Peterson and colleagues discovered isolates of the strand in the sink drain in their ICU.1 Tap water or material poured down the drain was a possible source of transmission. They subsequently identified inadequate drying of tap-water-rinsed nebulizer components used for medication administration as a possible cause; proximity of the stored patient supplies to sinks may have facilitated the exposure. In this case respiratory therapy procedure and training were reviewed and changed to eliminate the possibility of cross-contamination.

Over the past three months we at the Children’s Hospital of Philadelphia have had our first experiences with B. Cepacia colonization and infection in the non-CF population. Exposures initially seemed isolated to PICU patients, some of whom came in from outside already colonized and others of whom became colonized while in the hospital. However, we had three additional B. Cepacia positive patients in our cardiac intensive care unit as well. The commonalities between these patients included immunosuppression due to severity of illness or medication and lung transplantation.

As a CF center we have always had strict practices in place to isolate B. Cepacia CF patients from non-B. Cepacia CF patients, due to high morbidity and mortality from infection with this organism. Our infection prevention strategy includes placing patients in separate care areas and having them attend clinic on different days. Our B. Cepacia CF practices prompted these questions when we found the organism cultured in our non-CF patients:

1. Do these patients require isolation?
2. Do these patients need to be separated to avoid cross contamination?
3. Could equipment contamination be the source of infection?

The answers may or may not be what you would expect. We found that unless these patients have another organism (e.g. MRSA) that requires isolation, they do not need to be on contact precautions. Universal precautions will prevent the spread of the organism from caregivers to patients. We are not required to separate the non-CF B. Cepacia patients by location.

As part of the investigation into what might be causing clusters of B. Cepacia in our own institution we cultured equipment from all over the patient care environment, including respiratory equipment. This included the ventilator circuits, humidifiers, in-line suction devices, and bronchoscopes. Many of you remember the outbreak of Ralstonia in 2005 that was linked to the Vapotherm oxygen delivery device. To date, we have been unable to determine any contaminant that could be causing this outbreak.

During our investigation we learned from the Cystic Fibrosis Foundation’s Burkholderia CepaciaResearch Laboratory and Repository at the University of Michigan that this particular strain of B. Cepacia has been found in a number pediatric institutions across the country. The CDC is currently trying to determine similarities in the patients as well as any products that may have been used by them.

Looking toward the future, we will have to see what effects this B. Cepacia outbreak has on our non-CF patients, and whether or not it could potentially increase morbidity and mortality outside the CF population. Also, what does it mean for lung transplantation? We do not currently perform lung transplants on CF patients with B. Cepacia, but there are no guidelines outside that subset of patients. Additionally, our lung transplants recover immediately post-operatively in the cardiac intensive care unit and then transfer to other units within our institution when they are medically stable. We will need to look into making sure we continue to isolate B. Cepacia positive patients from our CF population, which may mean reevaluating where lung transplant patients are transferred within the institution. This means training staff to take care of these patients who have very specialized needs.

Figuring out all the details will likely take time. In the meantime we will continue to follow our strict infection control policies and work with the CDC to provide as much information as possible to explain the colonizations we have experienced and avoid further incidences.

References

1. Peterson AE, et al. Clonally related Burkholderia contaminans among ventilated patients without cystic fibrosis. Am J Infect Control 2013;41:1298-1300.
2. Forbes BS. Pseudomonas, Burkholderia and similar organisms. 2007 St. Louis: Elsevier.
3. Martin MC, et al. Hospital wide outbreak of Burkholderia contaminans caused by prefabricated moist washcloths. J Hosp Infect 2011;77:267-270

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Pediatric Lung Recruitment: Current Strategies

Rhonda M. Schum, BHS, RRT, Cincinnati Children’s Medical Center, Cincinnati, OH

Managing mechanically ventilated patients with acute lung injury (ALI) and/or atelectasis is continually evolving and recruitment maneuvers (RM) have become a beneficial strategy to optimize ventilation and oxygenation. However, the efficacy of RMs remains controversial.1

What is an RM?

Lung recruitment maneuvers are designed to increase transpulmonary pressure, thereby increasing the number of alveoli participating in gas exchange.2 This can be achieved by either a sustained inflation (SI) maneuver or pressure control (PCV). The use of an SI involves a breath holding technique. The PCV mode is performed through incremental and/or decremental PEEP titration. Both techniques may be performed with a flow inflation bag or manipulation of the ventilator.

How is the effectiveness of RMs measured?

Some of the more common measurements are dynamic compliance, exhaled tidal volume, and blood gas analysis by analyzing PaO2/FiO2. With additional diagnostic equipment that provides pulmonary mechanics values, more advanced information can be obtained to help assess the efficacy of RMs. More sophisticated measurements include alveolar tidal volume (Vt alv) and carbon dioxide elimination (VCO2).

What are the potential risks of receiving RMs?

Potential risks associated with RMs include hemodynamic instability, negatively impacting intracranial pressure, and barotrauma.2 Some patients with ALI are at risk for barotrauma due to surfactant deficiency, decreased lung compliance, and increased airway resistance. Shearing injury from under-recruited alveoli can cause further complications when RMs are being attempted. Emphasis must be placed on careful evaluation of patient tolerance by close monitoring of vitals.

Risks for patients undergoing RMs may include a reduction in cardiac output due to increased positive pressure as well. Some pediatric patients, such as those with congenital heart defects, are more sensitive to increased positive pressure and may experience a reduction in the blood flow that returns from the heart to the lungs. This reduction in blood flow can affect the patient’s stroke volume and place an increased workload on the heart. Careful monitoring of hemodynamics is an integral part of performing RMs.

What data are available for pediatrics?

In a pilot study Kheir and colleagues examined the effects of two types of lung recruitment maneuvers. Ten patients underwent an SI maneuver followed by a staircase recruitment strategy (SRS) and a downwards PEEP titration. The study authors recorded arterial blood gases, lung mechanics, hemodynamics, and functional residual capacity (FRC). Both the SI and SRS increased PaO2 and FRC. It was noted that the PaCO2 increased during the SRS phase, but did not significantly change the arterial pH. Also, there was transient desaturation associated with the maneuver; however, the SI and SRS were hemodynamically well tolerated.3

In a prospective cohort study Boriosi and colleagues utilized a two-step RM in 21 pediatric patients. The first maneuver placed the patient in assist control/pressure control mode with the pressure above PEEP set at 15 cm H2O. Peep was initiated at 8 cm H2O, and was increased by 2 cm H2O every minute until the PEEP yielding the highest critical opening pressure (Cdyn) was defined.

The second part of the study involved a decremental PEEP titration to find the critical closing pressure. This provided the highest Cdyn during decremental titration. Optimal PEEP was determined by the critical closing pressure plus 2 cm H2O. The primary outcome in this study was the PaO2/FiO2 ratio. In addition, hemodynamics, alveolar arterial oxygen gradient (A-a gradient), and Cdyn were measured. The PaO2/FiO2 increased immediately following RM. The A-a gradient decreased by 12% immediately after RM. Cdyn did not significantly change after RM. Overall, this study demonstrated that RMs were safe and well tolerated.1

A recent case study used RMs in a patient with an acute airway injury after surgery for long segment congenital tracheal stenosis.4 Dehiscence of the surgical site created the need for resting the airway by extubating the patient while on extracorporeal membrane oxygenation. After five days of rest, RMs were performed to recruit the alveolus. In this case, there were two options available for RMs. Physicians either ordered an SI 30-40 cm H2O for approximately 30 seconds or PCV mode 40/15 for 10 breaths. Both techniques were available and could be altered to best meet the patient’s demands. The patient’s hemodynamics and pulmonary mechanics were monitored pre, during, and post procedure. Results demonstrated an improvement post RM in VCO2, Cdyn, and Vt alv.

Another tool in our arsenal

There are limited studies involving RMs in children. The evidence that has been presented demonstrates various ways to perform these maneuvers. However, there is no consensus on which method may be superior. It also appears that no long-term outcomes have been measured, and there have been no studies evaluating morbidity and mortality in this population.

RMs have become another tool in our arsenal to improve lung mechanics in patients who are mechanically ventilated and difficult to manage. Even in the most severe scenarios, we have seen promising results for lung recruitment in pediatric patients.

References

1. Boriosi J, et al. Efficacy and safety of lung recruitment in pediatric patients with acute lung injury. Pediatr Crit Care Med 2011;12:431-436.
2. Jauncey-Cooke J, et al. Paediatric lung recruitment: a review of the clinical evidence. Paediatr Respir Rev 2014;Feb. 28:Epub ahead of print.
3. Kheir JN, et al. Comparison of 2 lung recruitment strategies in children with acute lung injury. Respir Care 2013;58:1280-1290.
4. Raake J, et al. Extracorporeal membrane oxygenation, extubation, and lung-recruitment maneuvers as rescue therapy in a patient with tracheal dehiscence following slide tracheoplasty. Respir Care 2011;56:1198-1202.

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