Accepted Manuscript Title: To be permissive or not to be, is it the question? Author: Michael Tipton PII: DOI: Reference:
S0300-9572(14)00572-3 http://dx.doi.org/doi:10.1016/j.resuscitation.2014.05.031 RESUS 6024
To appear in:
Resuscitation
Received date: Accepted date:
12-5-2014 12-5-2014
Please cite this article as: Tipton M, TO BE PERMISSIVE OR NOT TO BE, IS ITTHE QUESTION?, Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.05.031 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
RESUSCITATION: LETTER TO THE EDITOR TO BE PERMISSIVE OR NOT TO BE, IS ITTHE QUESTION?
ip t
Resuscitation following submersion (head under)remains a matter of some debate and a stumbling block to achieving a common policy between rescue services.We have suggested that survival/resuscitation is extremely unlikely if submerged longer than 30 minutes in water warmer than 6 °C and, survival/resuscitation is extremely unlikely if submerged longer than 90 minutes in water 6 °C or below1, 2.
us
cr
We have been criticised for being insufficiently permissive by suggesting limiting a search to 30 minutes in water warmer than 6°C3. Given this, I was encouraged to read the paper by Quan et al 4 and their support for our position for water warmer than 6°C. However, Quan et al also state that "this statement is also true for water temperatures of 6 °C or below". This is in contrast to our conclusion, indeedQuan et al state that “Tipton’s statement that “survival/resuscitation is extremely unlikely if submerged longer than 90 minutes in 6 °C or below” is overly permissive”.
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The differences aredue to the questions asked and the cases examined. Quan et al asked, "is there a relationship with water temperature, submersion duration and outcome?" Given that drowning can result from many factorsthe lack of a strong relationship with a single factor (water temperature) is understandable. Knowing that people can survive prolonged submersion we asked "isthere a relationship with age, temperatureetc in those surviving prolonged submersion?”That we only found a small number of cases of survival with good outcome following submersion of longer than 30 minutesis we believe, more a statement of fact than a “methodological limitation”; prolonged underwater survival is very rare. This conclusion is supported by Quan et al who found no submerged survival times longer than 27 minutes in1,094 submerged drowning cases over 21 years.
Ac ce p
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For the reasons stated, there is no linear relationship between submerged survival time and water temperature. However, a “threshold water temperature”of about 6°C appears to exist below which resides the remote possibility of prolonged submerged survival.We suspect that such cold water is required to significantly cool and therefore protect the brain selectively during drowning before cardiorespiratory arrest. Quan et al could not interrogate such data as they had no suitable cases of survival in their database (i.e. submersion >30 minutes with good outcome).
This topic has important practical implications; if you base a rescue policy on the paper of Quan et al you would consider switching from “search and rescue” to “body recovery” at 30 minutes in all water temperatures. If you consider the actual accounts of those who have survived longer than 30 minutes you would keep searching; we recommend up to 90 minutes if water temperature is 6°C or below.As this recommendation is based on actual incidents we would not regard it as “overly permissive”but, as we stated originally, it is for others to decide whether the risk and cost of extending searches is justified by the likelihood of a successful outcome.
References 1. Tipton M, Golden F. Decision-making guide for the search, rescue and resuscitation of submerged (head under) victims. Resuscitation 2011; 82: 819-824. 2. Tipton M, Golden F. (2013) Drowning: guidelines extant, evidence-based risk for rescuers? Resuscitation 2013 Feb;84(2):e31-2. doi: 10.1016/j.resuscitation.2012.08.339. Epub 2012 Oct 13. 3. Deakin C. Drowning: more hope for patients, less hope for guidelines. Resuscitation (Editorial) 2012; 84(2): e31-e32.
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4. Linda Quan, Christopher D. Mack C, Schiff M. Association of water temperature and submersion duration and drowning outcome. 2014; PII: S0300-9572(14)00114-2DOI: http://dx.doi.org/doi:10.1016/j.resuscitation.2014.02.024
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Michael Tipton, University of Portsmouth Portsmouth, United Kingdom.
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The author (M J Tipton) has no conflicts of interest to declare.
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S0300-9572(14)00572-3 http://dx.doi.org/doi:10.1016/j.resuscitation.2014.05.031 RESUS 6024
To appear in:
Resuscitation
Received date: Accepted date:
12-5-2014 12-5-2014
Please cite this article as: Tipton M, TO BE PERMISSIVE OR NOT TO BE, IS ITTHE QUESTION?, Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.05.031 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
RESUSCITATION: LETTER TO THE EDITOR TO BE PERMISSIVE OR NOT TO BE, IS ITTHE QUESTION?
ip t
Resuscitation following submersion (head under)remains a matter of some debate and a stumbling block to achieving a common policy between rescue services.We have suggested that survival/resuscitation is extremely unlikely if submerged longer than 30 minutes in water warmer than 6 °C and, survival/resuscitation is extremely unlikely if submerged longer than 90 minutes in water 6 °C or below1, 2.
us
cr
We have been criticised for being insufficiently permissive by suggesting limiting a search to 30 minutes in water warmer than 6°C3. Given this, I was encouraged to read the paper by Quan et al 4 and their support for our position for water warmer than 6°C. However, Quan et al also state that "this statement is also true for water temperatures of 6 °C or below". This is in contrast to our conclusion, indeedQuan et al state that “Tipton’s statement that “survival/resuscitation is extremely unlikely if submerged longer than 90 minutes in 6 °C or below” is overly permissive”.
d
M
an
The differences aredue to the questions asked and the cases examined. Quan et al asked, "is there a relationship with water temperature, submersion duration and outcome?" Given that drowning can result from many factorsthe lack of a strong relationship with a single factor (water temperature) is understandable. Knowing that people can survive prolonged submersion we asked "isthere a relationship with age, temperatureetc in those surviving prolonged submersion?”That we only found a small number of cases of survival with good outcome following submersion of longer than 30 minutesis we believe, more a statement of fact than a “methodological limitation”; prolonged underwater survival is very rare. This conclusion is supported by Quan et al who found no submerged survival times longer than 27 minutes in1,094 submerged drowning cases over 21 years.
Ac ce p
te
For the reasons stated, there is no linear relationship between submerged survival time and water temperature. However, a “threshold water temperature”of about 6°C appears to exist below which resides the remote possibility of prolonged submerged survival.We suspect that such cold water is required to significantly cool and therefore protect the brain selectively during drowning before cardiorespiratory arrest. Quan et al could not interrogate such data as they had no suitable cases of survival in their database (i.e. submersion >30 minutes with good outcome).
This topic has important practical implications; if you base a rescue policy on the paper of Quan et al you would consider switching from “search and rescue” to “body recovery” at 30 minutes in all water temperatures. If you consider the actual accounts of those who have survived longer than 30 minutes you would keep searching; we recommend up to 90 minutes if water temperature is 6°C or below.As this recommendation is based on actual incidents we would not regard it as “overly permissive”but, as we stated originally, it is for others to decide whether the risk and cost of extending searches is justified by the likelihood of a successful outcome.
References 1. Tipton M, Golden F. Decision-making guide for the search, rescue and resuscitation of submerged (head under) victims. Resuscitation 2011; 82: 819-824. 2. Tipton M, Golden F. (2013) Drowning: guidelines extant, evidence-based risk for rescuers? Resuscitation 2013 Feb;84(2):e31-2. doi: 10.1016/j.resuscitation.2012.08.339. Epub 2012 Oct 13. 3. Deakin C. Drowning: more hope for patients, less hope for guidelines. Resuscitation (Editorial) 2012; 84(2): e31-e32.
1 Page 1 of 3
4. Linda Quan, Christopher D. Mack C, Schiff M. Association of water temperature and submersion duration and drowning outcome. 2014; PII: S0300-9572(14)00114-2DOI: http://dx.doi.org/doi:10.1016/j.resuscitation.2014.02.024
Ac ce p
te
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M
an
us
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ip t
Michael Tipton, University of Portsmouth Portsmouth, United Kingdom.
2 Page 2 of 3
The author (M J Tipton) has no conflicts of interest to declare.
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Mike Tipton.
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