Comparison of weight per volume and protein nitrogen units in non-standardized allergen extracts: implications for prescribing subcutaneous immunotherapy

Abstract Background Allergen extracts used in subcutaneous immunotherapy can be standardized or non-standardized. Standardized extracts are available in specific biological potencies, presumably making their biological activity more consistent. The majority of allergen extracts are non-standardized and may have less consistent potencies. Non-standardized extracts are labeled as weight per volume or protein nitrogen units (PNUs). Neither method provides direct information regarding the extract’s biologic potency. The purpose of this study was to compare weight per volume versus PNU concentrations for 4 non-standardized allergen extracts prepared by two allergen manufacturers. The potencies were compared to current North American practice recommendations. Methods The weight per volume and PNU values were provided for 4 non-standardized extracts—birch, short ragweed, dog hair and Alternaria—from HollisterStier and Stallergenes Greer. Weight per volume and PNU concentrations were compared for each of these extracts from both manufacturers. From the raw data, we calculated the corresponding PNU values for a weight per volume of 1:100 and 1:200 for each extract. Similarly, we calculated the corresponding weight per volume including a range of PNU values, for 1000, 2000, 3000, 4000 and 5000 PNU/ml. Results Birch extract has low PNU concentration, below 5000, for a weight per volume of 1:200 for both HollisterStier and Stallergenes Greer. In contrast, for both HollisterStier and Stallergenes Greer ragweed extract, a weight per volume of 1:200 corresponds to a PNU concentration greater than 5000. Dog extract for a weight per volume of 1:200, and even for 1:100, corresponds to very low PNUs for both companies. For Alternaria, corresponding PNU concentrations for HollisterStier is low at only 500 while over 5000 for Stallergenes Greer. Conclusions Our results show variability when comparing weight per volume and PNU concentrations for both Hollister-Stier and Stallergenes Greer products. We suggest selecting a PNU dose that corresponds to a weight per volume of 1:200 as this may improve patient safety. Our recommendations for starting PNU dose for the four non-standardized extracts are 1500 for birch, 5000 for ragweed, 25 for dog, and 500 for Alternaria when using HollisterStier products; 2300 for birch, 5000 for ragweed, 1200 for dog, and 5000 for Alternaria when using Stallergenes Greer products. If the starting PNU concentration is considerably below 5000 for a weight per volume of 1:200 slow up-titration is advised. Conversely, for PNU concentrations above 5000 for weight per volume of 1:200 we suggest a maintenance dose of 5000 PNU.

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Comparison of Weight Per Volume and Protein Nitrogen Units in Non-standardized Allergen Extracts: Implications for Prescribing Subcutaneous Immunotherapy

10.21203/rs.3.rs-350670/v1 ◽

2021 ◽

Author(s):

Benny Dua ◽

Jane Park ◽

Harold Kim

Keyword(s):

Biological Activity ◽

Patient Safety ◽

Maintenance Dose ◽

Improve Patient Safety ◽

Subcutaneous Immunotherapy ◽

Protein Nitrogen ◽

Direct Information ◽

Practice Recommendations ◽

Allergen Extracts ◽

Improve Patient

Abstract BackgroundAllergen extracts used in subcutaneous immunotherapy are standardized or non-standardized. Standardized extracts are available in specific biological potencies, presumably making their biological activity more consistent. The majority of allergen extracts are non-standardized and may have less consistent potencies. Non-standardized extracts are labeled as weight per volume or protein nitrogen units (PNUs). Neither method allows for any direct information regarding the extract’s biologic potency. The purpose of this study was to compare weight per volume versus PNU concentrations for 4 non-standardized allergen extracts prepared by two allergen manufacturers. The potencies were compared in application in current North American practice recommendations.MethodsThe weight per volume and PNU values were provided for 4 non-standardized extracts – birch, short ragweed, dog hair and Alternaria – from HollisterStier and Stallergenes Greer. Weight per volume and PNU concentrations were compared for each of these extracts from both manufacturers. From the raw data, we calculated the corresponding PNU values for a weight per volume of 1:100 and 1:200 for each extract. Similarly, we calculated the corresponding weight per volume for a range of PNU values, for 1000, 2000, 3000, 4000 and 5000 PNU/ml.ResultsBirch extract has low PNU concentration, below 5000, for a weight per volume of 1:200 for both HollisterStier and Stallergenes Greer. In contrast, for both HollisterStier and Stallergenes Greer ragweed extract, a weight per volume of 1:200 corresponds to a PNU concentration greater than 5000. Dog extract for a weight per volume of 1:200, and even for 1:100, corresponds to very low PNUs for both companies. For Alternaria, corresponding PNU concentrations for HollisterStier is low at only 500 while over 5000 for Stallergenes Greer. Corresponding weight per volumes for PNU values for these extracts can be found in the manuscript.Conclusions Our results show variability when comparing weight per volume and PNU concentrations for both Hollister-Stier and Stallergenes Greer products. We suggest selecting a PNU dose that corresponds to a weight per volume of 1:200 as this may improve patient safety. Our recommendations for starting PNU dose for the four non-standardized extracts are highlighted in the manuscript. If the starting PNU concentration is considerably below 5000 for a weight per volume of 1:200 slow up-titration is advised. Conversely, for PNU concentrations above 5000 for weight per volume of 1:200 we suggest a maintenance dose of 5000 PNU.

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More Accountability Is Needed to Improve Patient Safety

Skin & Allergy News ◽

10.1016/s0037-6337(09)70568-6 ◽

2009 ◽

Vol 40 (11) ◽

pp. 40 ◽

Cited By ~ 1

Author(s):

SUSAN BIRK

Keyword(s):

Patient Safety ◽

Improve Patient Safety ◽

Improve Patient

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Exploiting mistakes as learning opportunities to improve patient safety

PsycEXTRA Dataset ◽

10.1037/e544792013-003 ◽

2012 ◽

Author(s):

Florina Spanu

Keyword(s):

Patient Safety ◽

Improve Patient Safety ◽

Learning Opportunities ◽

Improve Patient

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Inpatient Prostacyclin Administration Errors: An Opportunity to Improve Patient Safety

Advances in Pulmonary Hypertension ◽

10.21693/1933-088x-9.3.171 ◽

2010 ◽

Vol 9 (3) ◽

pp. 171-171

Author(s):

Martha Kingman

Keyword(s):

Patient Safety ◽

Improve Patient Safety ◽

Improve Patient

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Writing’s on the wall: improving the WHO Surgical Safety Checklist

BMJ Open Quality ◽

10.1136/bmjoq-2020-001086 ◽

2021 ◽

Vol 10 (1) ◽

pp. e001086

Author(s):

Claire Cushley ◽

Tom Knight ◽

Helen Murray ◽

Lawrence Kidd

Keyword(s):

Patient Safety ◽

Online Survey ◽

Improve Patient Safety ◽

Surgical Safety Checklist ◽

Surgical Safety ◽

Time Out ◽

Mandatory Requirement ◽

Who Checklist ◽

Improve Patient ◽

Theatre Team

Background and problemThe WHO Surgical Safety Checklist has been shown to improve patient safety as well as improving teamwork and communication in theatres. In 2009, it was made a mandatory requirement for all NHS hospitals in England and Wales. The WHO checklist is intended to be adapted to suit local settings and was modified for use in Gloucestershire Hospitals NHS Foundation Trust. In 2018, it was decided to review the use of the adapted WHO checklist and determine whether improvements in compliance and engagement could be achieved.AimThe aim was to achieve 90% compliance and engagement with the WHO Surgical Safety Checklist by April 2019.MethodsIn April 2018, a prospective observational audit and online survey took place. The results showed compliance for the ‘Sign In’ section of the checklist was 55% and for the ‘Time Out’ section was 91%. Engagement by the entire theatre team was measured at 58%. It was proposed to move from a paper checklist to a wall-mounted checklist, to review and refine the items in the checklist and to change the timing of ‘Time Out’ to ensure it was done immediately prior to knife-to-skin.ResultsFollowing its introduction in September 2018, the new wall-mounted checklist was reaudited. Compliance improved to 91% for ‘Sign In’ and to 94% for ‘Time Out’. Engagement by the entire theatre team was achieved 100% of the time. Feedback was collected, adjustments made and the new checklist was rolled out in stages across all theatres. A reaudit in December 2018 showed compliance improved further, to 99% with ‘Sign In’ and to 100% with ‘Time Out’. Engagement was maintained at 100%.ConclusionsThe aim of the project was met and exceeded. Since April 2019, the new checklist is being used across all theatres in the Trust.

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Understanding safety in healthcare: the system evolution, erosion and enhancement model

Journal of Public Health Research ◽

10.4081/jphr.2013.e25 ◽

2013 ◽

Vol 2 (3) ◽

pp. 25 ◽

Cited By ~ 5

Author(s):

Jane Carthey

Keyword(s):

Patient Safety ◽

Complex Systems ◽

Human Error ◽

Improve Patient Safety ◽

New Model ◽

System Evolution ◽

Accident Causation ◽

System Migration ◽

Improve Patient

The paper summarises previous theories of accident causation, human error, foresight, resilience and system migration. Five lessons from these theories are used as the foundation for a new model which describes how patient safety emerges in complex systems like healthcare: the System Evolution Erosion and Enhancement model. It is concluded that to improve patient safety, healthcare organisations need to understand how system evolution both enhances and erodes patient safety.

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Atmung – Standardisierte Checkliste macht Intubation von Neugeborenen sicherer

Gesundheitsökonomie & Qualitätsmanagement ◽

10.1055/s-0043-112240 ◽

2017 ◽

Vol 22 (03) ◽

pp. 124-125

Author(s):

Maria Weiß

Keyword(s):

Intensive Care Unit ◽

Patient Safety ◽

Intensive Care ◽

Neonatal Intensive Care Unit ◽

Neonatal Intensive Care ◽

Improve Patient Safety ◽

Improve Patient

Hatch LD. et al. Intervention To Improve Patient Safety During Intubation in the Neonatal Intensive Care Unit. Pediatrics 2016; 138: e20160069 Kinder auf der Neugeborenen-Intensivstation sind besonders durch Komplikationen während des Krankenhausaufenthaltes gefährdet. Dies gilt auch für die Intubation, die relativ häufig mit unerwünschten Ereignissen einhergeht. US-amerikanische Neonatologen haben jetzt untersucht, durch welche Maßnahmen sich die Komplikationsrate bei Intubationen in ihrem Perinatal- Zentrum senken lässt.

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