White Papers

Radioaerosol Lung Imaging:

Potter, R. and King, R.  “Radioaerosol Inhalation Lung Scanning—A New Generation”.  Medi/Nuclear Corp., Inc.

Summary:  The development of radioaerosol lung scanning devices over the years have been focused on overcoming the shotcomings of central and trachael deposition.  The challenge was to develop a device design that provided deep lung penetration through small particles, with quick delivery time to the patient.  There are a number factors that must be considered in aerosol delivery that are somewhat at odds with each other, with regards to device design, that had to be overcome.  The impact of the device design on particle size and aerosol genertion rate were tested.  The resulting nebulizer design was put into production for Medi/Nuclear® Corp.

 

Medicator® for Aerosol Delivery: 

McPeck, Michael.  “Healthline Medical Aerosol Laboratory Testing of Hudson #1755 Iso-Neb for City of Hope Respiratory Care Department”.  19 August 2005.

Summary: The City of Hope RC department trialed the Healthline Model #AM-602 Medicator Aerosol Maximizer on August 18, 2005 to deliver pentamadine.  The Medicator was loaded with the same amount of drug (300mg) with which City of Hope typically loads into the Hudson #1755 Iso-Neb aerosol device.  This test compared the Medicator Aerosol Maximizer to the Hudson UpDraft II tee nebulizer and the Hudson #1755 Iso-Neb.  The Hudson UpDraft II began sputtering around 6 minutes and stopped producing aerosol at 9 minutes, in which the Inhaled Mass was 12.1 percent.  The Hudson #1755 Iso-Neb sputtered at 4.5 minutes and stopped producing aerosol by 9 minutes, resulting in an Inhaled Mass of about 12.1 percent.  In contrast, the Medicator using a MistyMax 10 nebulizer sputtered around 2 minutes and stopped producing aerosol by 9 minutes, resulting in an Inhaled Mass of approximately 30 percent.  The results of this test show that the Medicator Aerosol Maximizer is a much more efficient system of aerosol delivery.

 

McPeck, Michael.  “Waste Not, Want Not: How the Medicator Maximizer® Aerosol Delivery Device Tackles an Old Problem”.  FOCUS: Journal for Respiratory Care and Sleep Medicine, Winter 2005.

Summary: The Medicator® Aerosol Maximizer can be used for aerosol delivery of a variety of drugs, such as bronchiodialators, antimicrobials (e.g., tobramycin, pentamadine), morphone and fentanyl, and experimental drugs.  The Medicator® includes an elastic reservoir bag and a unique valve to double the amount of aerosolized drug that is inhaled by the patient, while significantly reducing the amount of aerosol released into the atmosphere.  This product stores the aerosol that is generated during the patient’s exhalation phase into the non-latex elastic reservoir bag, and releases it to the patient on the subsequent breath, with a slight boost from the elastic recoil of the expanded bag, along with the other aerosol that the nebulizer is generating.  The implications of the Medicator’s® new approach to aerosol delivery are many: 1) simple, inexpensive nebulizers can be attached to the Medicator® Maximizer, which will approximately double delivery or halve the amount of time it takes to deliver an equivalent effective dose of medication, 2) delivery time can be shortened to about three minutes for routine bronchiodialator therapy and to about seven minutes for rescue therapy with bronchiodialators, 3) expensive concentrated medications in unit dose ampoules can be avoided in favor of less expensive counterparts, 4) when drugs other than bronchiodialators (e.g., antimicrobials) it makes sense to use a system that can deliver as much of the drug as possible for maximum therapeutic value, and 5) the Medicator’s® quasi-closed system resulting in consistent aerosol delivery at different times in the same patient, even when the breathing pattern has changed due to disease, anxiety or distress.

 

 

Presentations

Aerosol Particle Sizes:

Francken, G. A., Waxman, A .D., Potter, R., and King, R.  “The Effect of Inertial Changes on Particle Size Distribution in Nebulizers Systems: The Impact on Clinical Aerosol Studies”.  22nd Annual Western Regional Meeting of the Society of Nuclear Medicine, Monterey, CA.  September 18-21, 1997.

Summary:  Previous studies have shown that aerosol particle size plays a major role in determining the quality of aerosol images produced from a nebulized radiopharmaceutical.  The purpose of the current study was to compare a standard commercially available nebulizer with two modified systems with regards to particle size distribution and quality of aerosol image production.

 

Xenon v. Radioaerosol:

Hyun, M. C., Waxman, A. D., D’ Agnolo, A., Potter, R.  “Comparison of Xenon and a Modified Nebulizer for Aerosol Ventilation in the Diagnosis of Pulmonary Embolus: Impact on the Intermediate PIOPED Category”.  46th Annual Meeting of the Society of Nuclear Medicine, Los Angeles, CA.  June 6-10, 1999.

Summary: Using PIOPED criteria for evaluation of suspected pulmonary embolism, 39% of patients in the initial study (JAMA) were assigned in intermediate category.  The initial study utilized Xenon-133 for ventilation.  A subsequent study (Journal of Nuclear Medicine 1995) using modified PIOPED criteria and aerosol ventilation demonstrated that 17.4% assignment for the intermediate category.  The purpose of the current study was to evaluate the intermediate category assignment for patients who underwent pre-perfusion Xenon or pre-perfusion aerosol imaging using modified PIOPED criteria.

 

V/Q Imaging:

Hyun, M., Corbilla, R., D' Agnolo, A., and Waxman, A.  "Co-Registration of Ventilation and Perfusion SPECT Imaging: Comparison with Planar".  Western Regional-Society of Nuclear Medicine.  May 2001.

Summary: A successful V/Q scan technique may improve image quality as well as sensitivity and specificity.  The improved ventilation technique demonstrated improved image quality with reduced breathing time.  The SPECT imaging performed in perfusion lung scan demonstrated more abnormalities than the planar images.  The purpose of this study was to validate a SPECT methodology fro co-registered ventilation and perfusion lung scans and compare this new technique with established planar techniques.  

 

Nebulizers: 

Hyun, M., Waxman, A., D’Angelo A., Potter, R., King, R., and Cohen, I.  “The Impact of a Holding Compartment on Aerosol Delivery from Nebulizer Systems”.  23rd Annual Western Regional Meeting of the Society of Nuclear Medicine, Long Beach, CA.  October 22-25, 1998.

Summary: Submiconic nebulizer systems require 5 minutes or longer of breathing from a 20/mCi/mL reservoir to obtain the necessary counts to perform a pre-perfusion aerosol study.  The purpose of the current study was to evaluate the potential use of a holding compartment in order to imporve aerosol delivery efficiency without sacrificing image quality.  

 

Hyun, M., Waxman, A., Potter, R., and King, R.  “Improvement in the Aerosol Delivery from a Standard Nebulizer System: The Use of a Holding Compartment”.  45th Annual Meeting of the Society of Nuclear Medicine, Toronto, Ontario, CAN.  June 7-11, 1998.

Summary: Current submicronic nebulizer systems would require approximately 5 minutes of breathing using a 20/mCi/mL reservoir dose to obtain sufficient counts for a pre-perfusion aerosol study.  This breathing time for many patients is excessive.  The purpose of the aerosol study was to evaluate a new nebulizer system using a holding cpmpartment to improve efficiency of aerosol delivery.

 

Medicator® for Aerosol Delivery:

Chatburn, Robert L. and Williams, Thomas, J.  “Effect of Conserver Systems on Jet Nebulizer Performance”.  AARC Open Forum.  Respiratory Care 2009.

Summary: The purpose of the study was to compare four different nebulizer configurations: 1) a standard continuous flow nebulizer with a simple flex tube reservoir, 2) a standard continuous flow nebulizer with a valve/bag conserver system (Healthline Medicator Plus), 3) a dosimetric nebulizer operated in a breath actuated mode, and 4) a dosimetric nebulizer operated in the continuous flow mode.  Differences among the nebulizer configurations for system efficiency and component efficiencies (i.e., nebulizer, delivery and conserver efficiency) were tested.  For the systems tested, the bag/valve conservers improve nebulizer performance compared to the standard flex tube. 

 

McPeck, Michael, King, Russell, and Samford, Glenn.  “Can Aerosol Drug Delivery in SVN be Predicted?”  Respiratory Care 2003.  48(11): 1080.      

Summary: Accurate predictions of inhaled mass (IMp) has been impractical because the efficiency of small-volume nebulizers (SVNs) and their delivery systems is generally low and drug delivery is variable and imprecise due to differences in patients’ breathing patterns.  The purpose of the study was to determine whether a high-efficiency aerosol system (Healthline Medicator® Aerosol Maximizer) that negated the effect of different breathing patterns would reduce the variability and permit application of a predictive formula.  A formula that predicted Inhaled Mass for aerosolized albuterol using the Medicator® Plus Aerosol Maximizer was proposed.  To test the validity of the proposed formula, six volunteer subjects received a “treatment” of radiolabeled unit-dose albuterol administered by the Medicator® Plus.  Findings suggested that because the Medicator® stores the aerosol generated during exhalation for the subsequent inhalation in the reservoir bag, the effect of breathing pattern on aerosol delivery, increase System Efficiency fraction, and may make the application of this or other prediction formulas for Inhaled Mass possible.   

 

McPeck, Michael, Potter, Ross, and Samford, Glenn.  “Reservoir Bag in Medicator Aerosol Delivery System Does Not Contaminate the Nebulizer or the Patient”.  AARC Open Forum.  Las Vegas, NV.  December 8-11, 2003.

Summary: This study sought to examine whether any microbiologic contamination that may be present in the reservoir bag of the Healthline Medicator aerosol delivery system may be inhaled by the patient.  The Medicator utilizes a reservoir bag, as well as a manifold, specifically designed so that aerosols and particulate matter exhaled by the patient are 1) channeled through a specific exhalation port to the atmosphere and 2) segregated from both the nebulizer and reservoir bag by a unidirectional diaphragm to ensure that the reservoir bag does not become contaminated.  Testing of the manifold in preventing contamination of the reservoir bag utilized a radioactive tracer as a surrogate for microorganisms.  Findings from this study showed that the radioactivity that was intentionally placed in the bags did not contaminate the nebulizer or the HEPA filter.  The study concluded that even though it is likely for contamination to reach the reservoir bag in the first place, contamination of the reservoir bag will not result in contamination of the nebulizer or the patient. 

 

McPeck, Michael, Samford, Glenn, Potter, and King, Russell.  “Can a ‘Holding Chamber’ Improve Nebulizer Performance?” Respiratory Care 2004.  49(11): 1393.

Summary: Holding chambers are now commonly used to increase the aerosol delivery performance of metered-dose inhalers (MDIs).  The Healthline Medicator® Aerosol Maximizer is claimed to act like a holding chamber for small-volume medication nebulizers (SVNs).  The Inhaled Mass output of a variety of typical Tee-style SVNs, and whether and how much the Medicator® can increase the aerosol delivery of those SVNs were tested using nine different models of plastic disposable jet SVNs.  Results showed that the Medicator® Aerosol Maximizer increases the delivery of aerosol to the mouth by an average of 2.4 times that of conventional SVNs on Tee setups. 

 

McPeck, Michael, Samford, Glenn, Potter, Ross, and Snitily, Timothy.  “Is a Noseclip Necessary for Small Volume Nebulizer Treatments?”  Respiratory Care 2003.  48(11): 1079. 

Summary: Many patients do not use noseclips when receiving aerosol therapy via a small-volume nebulizer (SVN), so this study sought to investigate whether the use of noseclips improved aerosol delivery.  Six subjects received aerosolized albuterol by mouth (HEPA filters placed at the mouthpiece) using the Healthline Medicator® Plus Aerosol Maximizer.  The subjects did not use noseclips during the first treatment, but did use noseclips during the second treatment.  After each treatment the filters were measured.  Although aerosol delivery increased, the results were not statistically significant, possibly due to the small sample size.  The use of noseclips may modestly increase aerosol delivery and may reduce variability, especially among occasional patients and predominately nose-breathers.

 

McPeck, Michael, Samford, Glenn, Potter, Ross, and King, Russell.  “Mitigation of Occupational Exposure to Aerosolized Medication”.  Respiratory Care 2004.  49(11): 1390.

Summary: Although there is sparse data on occupational exposure to aerosolized medication, a link to occupational asthma in respiratory therapists has been suggested.  Nine different plastic disposable nebulizers were tested to measure waste aerosol during exhalation during the breathing cycle.  The waste aerosol for the nine nebulizers varied from 21.7 to 36.0% on the Tee set-up and 7.6 to 12.9% on the Medicator®.  The Medicator®, with and without a filter, retained the aerosol generated by exhalation and inhaled during the subsequent breath, which significantly reduced waste aerosol. 

 

McPeck, Michael, Potter Ross, and Samford, Glenn.  “Validation of the Medicator® Plus ‘Aerosol Maximizer’: Comparison to a Commercial Reservoir-Type Delivery System and a Standard ‘Tee’ System”.  Respiratory Care 2003.  48(11): 1080.

Summary: This purpose of this study was to compare the Medicator® Plus to other commercially available aerosol delivery systems.  The comparison showed that Inhaled Mass was 24.8%, 18%, and 14.6% for the Medicator®, “tee”, and Circulaire, respectively.  The Medicator®, used with the same nebulizer as the other two systems, delivered 2.1 times as much total albuterol as the Circulaire and 1.4 times as much as the “tee”.  Additionally, the Medicator® delivered 1.8 times as much albuterol in 6 minutes as the Circulaire and standard “tee”. 

 

McPeck, Michael.  “An Improved Device and Patient Interface for Delivering Aerosolized Medications to Patients with Tracheotomies”.  AARC Open Forum.  Respiratory Care 2005.   

Summary: This study sought to answer the following questions: 1) How much aerosol is typically delivered via a Tee nebulizer connected to a trach collar? And 2) Does the Medicator® aerosol delivery system improve aerosol drug delivery with a direct connection to the trach tube?  When connected directly to the trach tube with a special adapter, the Medicator® rendered 6.4 times greater albuterol delivery than with the same nebulizer on a Tee with a trach collar.  This finding suggests that the Medicator® could be useful for improving and guaranteeing the efficacy of aerosol drug delivery to spontaneously breathing patients with artificial airways.

 

McPeck, Michael.  “Room Air Entrainment Threshold of the Medicator Mobius”.  AARC Open Forum.  Respiratory Care 2007.

Summary: This study asked the following question: Does the low-flow paradigm of the Mobius to room air entrainment (RAE) that would dilute the He portion of the HeO2 mixture to unacceptable levels?  Testing conditions included tidal volumes (VT) of 200, 300, 400, and 500 mL with respiratory frequencies (f) of 10, 20, 25, 30, 35, 40, and 45 BPM resulting in minute volumes (Vmin) of 2.0 to 22.5 L/min., generated by a sine wave piston ventilator at I:E of 1:1.  A 6 in. corrugated tube was used to connect the piston ventilator to the mask (patient) position on the patient tee.  The Mobius was operated with an 80/20 HeO2 mixture powering 90mL capacity nebulizer at a flow of 8 L/min.  Data from this study indicate that the threshold for clinically significant air entrainment with the Medicator Mobius is at a VT of 400 mL and a f of at least 30 BPM (Vmin=12 L/min.).  The Medicator Mobius can be used in acute asthmatics with tidal volumes as high as 200-400 mL with no clinically significant RAE, even at breathing rates up to 30 BPM.