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Validation of Aspiration Markers

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02301845
Recruitment Status : Withdrawn (IRB disapproval)
First Posted : November 26, 2014
Last Update Posted : March 16, 2016
Information provided by (Responsible Party):
Lorenzo Berra, MD, Massachusetts General Hospital

Brief Summary:
This is an interventional crossover study aimed at validating diatom shells as a marker for cuff leak and microaspiration in mechanically ventilated, critically ill patients.

Condition or disease Intervention/treatment Phase
Pneumonia, Aspiration Drug: Diatoms Shells Phase 1

Detailed Description:
At present there is no standard method for the evaluation of in vivo cuff leak and aspiration. Most of the tested techniques have major pitfalls that render their routine application infeasible. Lacking a practical and reliable marker, any possible intervention aimed at improving cuff seal and ETT performance in order to reduce VAP occurrence is going to be hindered by the inability to truly evaluate its efficacy. Radiolabeled markers are expensive, expose the patient to considerable radiological risk, and require transport to a radiological department, which would expose critically ill patients to additional risk. Dyes have the potential to give useful information about the presence of a cuff leak, but due to persistent staining of secretions, they do not allow continuous monitoring of aspiration. Amylase detection could be a good marker of aspiration, but its ability to detect aspiration is poor even when compared to pepsin. Pepsin and bile acids have the potential to detect some of the aspirations and cuff leaks that happen daily in mechanically ventilated patients, but due to their gastrointestinal nature, they do not offer any kind of information about aspiration of contaminated oropharyngeal secretions. With this research protocol, we would like to validate the use of diatom skeletons suspended in saline as a marker for determining cuff leakage and aspiration events in an ICU population and compare its efficacy in identifying aspiration events with pepsin detection. Diatoms are a major group of algae, composing the majority of phytoplankton. Their diameter is 5-15 μm on average and 1 ml of seawater usually contains about 104 diatoms. They are unicellular organisms and their main feature is that they are enclosed within a cell wall made of amorphous silica, biopolymerized in a geometric fashion that is species-dependent. At the end of their vital cycle, diatom shells deposit at the bottom of the sea. Diatom shell deposits have been found in almost every place on Earth, and are the main component of diatomaceous earth (DE). DE is an extremely fine powder composed of diatom shells that have accumulated over thousands of years. Due to its microscopical texture and inexpensive nature, it is commonly employed as a filtering media for beverages and a drying and anti-mold agent for cereals. Diatom shells compose food-grade DE in its entirety. Due to its non-crystalline, amorphous nature, it is essentially nontoxic. Our hypothesis is that administration of 10 mg of DE suspended in 10 ml of saline into the pharyngeal cavity of intubated patients will act as a reliable marker of cuff leak and aspiration in critically ill patients. Thanks to their geometric shape, diatom shells should be easily detectable in tracheal secretions when observed under a microscope. The number of diatoms-per-field observed under a fixed magnification will allow for the detection of microaspiration in a qualitative and quantitative way. The introduction of this new, safe and inexpensive marker for evaluating ETT cuff performance and for detecting aspiration will improve the design of future studies aimed at VAP prevention

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 0 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Validation of a Marker for Aspiration and Endotracheal Tube Cuff Leak.
Study Start Date : February 2016
Estimated Primary Completion Date : March 2016
Estimated Study Completion Date : March 2016

Arm Intervention/treatment
Experimental: Suspended Diatoms
Suspended diatom shells (10 mg/ 10 ml of saline) will be instilled in the oral cavity of the study subject every 12 hours for the first three study days. The total amount of amorphous silica administered will be 20 mg/day, which is the average daily intake of amorphous silica in normal human diet (0.3 mg/kg body weight/day)
Drug: Diatoms Shells
Instillation of suspended diatom shells - 10 mg q12h

Primary Outcome Measures :
  1. Cuff leak and microaspiration [ Time Frame: 3 days ]
    The investigators will collect samples of tracheal secretions below the cuff every 4 hours after the first pharyngeal administration of diatom shells and after 12 hours from the other 5 scheduled administrations of diatom shells. Samples will be centrifuged and the sediment observed under microscopy for detection of shells in tracheal secretions below the endotracheal tube cuff. Their presence will be a sign of cuff leak and aspiration. The ratio between administered diatom shells and collected diatom shells will be used to give an estimate of leakage.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Age ≥ 18 years;
  2. Admission to Surgical ICUs (Ellison 4 or Blake 12);
  3. Patients expected to be intubated for at least 48 hours or longer from the time of enrollment.

Exclusion Criteria:

  1. High PEEP requirement at enrollment (PEEP higher than 8 cmH2O)
  2. Diagnosis of ARDS (any severity)
  3. Status asthmaticus
  4. Current or past participation in another interventional trial conflicting with the present study;
  5. Pregnant women;
  6. Prisoner status;
  7. Patients who had partial or total gastrectomy.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02301845

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United States, Massachusetts
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
Sponsors and Collaborators
Massachusetts General Hospital
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Principal Investigator: Lorenzo Berra, MD Massachusetts General Hospital

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Responsible Party: Lorenzo Berra, MD, Staff Anesthetist, Massachusetts General Hospital Identifier: NCT02301845     History of Changes
Other Study ID Numbers: Creatures
First Posted: November 26, 2014    Key Record Dates
Last Update Posted: March 16, 2016
Last Verified: March 2016

Keywords provided by Lorenzo Berra, MD, Massachusetts General Hospital:
Respiration, artificial

Additional relevant MeSH terms:
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Pneumonia, Aspiration
Lung Diseases
Respiratory Tract Diseases
Respiratory Tract Infections