The University of Southampton
University of Southampton Institutional Repository

How often should defibrillation pads be changed?: the effect of evaporative drying

How often should defibrillation pads be changed?: the effect of evaporative drying
How often should defibrillation pads be changed?: the effect of evaporative drying
Objective: In order to minimise transthoracic impedance (TTI) during defibrillation, water-based pads are used to improve conductivity between metal defibrillation paddles and skin. Subjectively, these pads appear to dry very quickly; an effect that may lead to an increase in TTI due to poorer conduction between paddles and skin. This study was carried out to assess the effect of evaporative drying of defibrillation pads on TTI. Materials and methods: TTI was measured at 5–10 min intervals in 20 adult male volunteers across 3M defibrillation pads (2346N) placed in the anterior–apical position. Measurements of TTI were made at 30 kHz using a Bodystat® MultiScan 5000 monitor at end-expiration. A third pad was placed on the left precordium and its mass recorded each time a TTI measurement was made. Results: The median age of subjects was 22 years (range 21–52 years) and their median body mass index was 23.1 kg m?2 (range 18.4–42.8 kg m?2). Median room temperature was 23.0°C (range 19.0–24.0°C) and the median humidity was 31.0% (range 28.0–48.0%). 3M defibrillation pads had an initial mean mass of 25.14 g (S.D.±0.41 g). Changes in defibrillation pad mass due to evaporative loss occurred immediately and rapidly, with all measurements being significantly lower than the baseline value. Mean baseline TTI was 63.6 ? (S.D.±13.7 ?). After 30 min a statistically significant (P=0.012) rise of 1.4 ? (2.2%), was observed corresponding to a 12.6% decrease in pad mass, after which TTI continued to increase in a linear fashion. Conclusion: In the absence of a defibrillation current, 3M defibrillation pads can safely be left on the chest wall for at least 25 min in a typical hospital environment before evaporative drying results in a significant increase in transthoracic impedance.
0300-9572
157-62
Deakin, C.D.
560d993b-bbc9-4548-9990-272ed18a011d
Petley, G.W.
4f2da40b-3c7b-4adc-b75c-e24e62bb1cf0
Drury, N.E.
1cb50ec1-1902-4132-95ec-942f4c7e2217
Clewlow, F.
06b8840f-4ccd-48cc-9a1e-d89f4960960d
Deakin, C.D.
560d993b-bbc9-4548-9990-272ed18a011d
Petley, G.W.
4f2da40b-3c7b-4adc-b75c-e24e62bb1cf0
Drury, N.E.
1cb50ec1-1902-4132-95ec-942f4c7e2217
Clewlow, F.
06b8840f-4ccd-48cc-9a1e-d89f4960960d

Deakin, C.D., Petley, G.W., Drury, N.E. and Clewlow, F. (2001) How often should defibrillation pads be changed?: the effect of evaporative drying. Resuscitation, 48 (2), 157-62. (doi:10.1016/S0300-9572(00)00251-3). (PMID:11426477)

Record type: Article

Abstract

Objective: In order to minimise transthoracic impedance (TTI) during defibrillation, water-based pads are used to improve conductivity between metal defibrillation paddles and skin. Subjectively, these pads appear to dry very quickly; an effect that may lead to an increase in TTI due to poorer conduction between paddles and skin. This study was carried out to assess the effect of evaporative drying of defibrillation pads on TTI. Materials and methods: TTI was measured at 5–10 min intervals in 20 adult male volunteers across 3M defibrillation pads (2346N) placed in the anterior–apical position. Measurements of TTI were made at 30 kHz using a Bodystat® MultiScan 5000 monitor at end-expiration. A third pad was placed on the left precordium and its mass recorded each time a TTI measurement was made. Results: The median age of subjects was 22 years (range 21–52 years) and their median body mass index was 23.1 kg m?2 (range 18.4–42.8 kg m?2). Median room temperature was 23.0°C (range 19.0–24.0°C) and the median humidity was 31.0% (range 28.0–48.0%). 3M defibrillation pads had an initial mean mass of 25.14 g (S.D.±0.41 g). Changes in defibrillation pad mass due to evaporative loss occurred immediately and rapidly, with all measurements being significantly lower than the baseline value. Mean baseline TTI was 63.6 ? (S.D.±13.7 ?). After 30 min a statistically significant (P=0.012) rise of 1.4 ? (2.2%), was observed corresponding to a 12.6% decrease in pad mass, after which TTI continued to increase in a linear fashion. Conclusion: In the absence of a defibrillation current, 3M defibrillation pads can safely be left on the chest wall for at least 25 min in a typical hospital environment before evaporative drying results in a significant increase in transthoracic impedance.

Full text not available from this repository.

More information

Published date: February 2001
Organisations: Clinical & Experimental Sciences

Identifiers

Local EPrints ID: 383383
URI: https://eprints.soton.ac.uk/id/eprint/383383
ISSN: 0300-9572
PURE UUID: d161b8ae-8c85-4a12-9aec-bf15e3f43082
ORCID for G.W. Petley: ORCID iD orcid.org/0000-0002-3295-0444

Catalogue record

Date deposited: 28 Jan 2016 16:51
Last modified: 31 Jul 2019 00:50

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×