Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest:
None applicable for any author/collaborator.
The following Task Force members, other authors or collaborators declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees:
None applicable for any author/collaborator.
CoSTR Citation
Therese Djärv, Matthew Douma, Tina Palmieri, Daniel Meyran, David Berry, David Kloeck,
Jason Bendall, Laurie J. Morrison, Eunice M. Singletary, David Zideman, on behalf of the International Liaison Committee on Resuscitation (ILCOR First Aid and Pediatric Life Support Task Forces, 2021 February 22. Available from: http://ilcor.org
Members of the International Liaison Committee on Resuscitation First Aid Task Force who met criteria as a collaborator include: Vere Borra, Jestin N Carlson, Pascal Cassan, Michael Nemeth, Richard Bradley, Wei-Tien Chang, Nathan P Charlton, Jonathan L Epstein, Aaron Orkin. Sakamoto Tetsuya, Craig Goolsby
Acknowledgements: Besides the authors Therese Djärv, Matthew Douma, Tina Palmieri, Daniel Meyran, David Berry, David Kloeck, Jason Bendall, Laurie J Morrison, Eunice M. Singletary and David Zideman and collaborators Vere Borra, Jestin N Carlson, Pascal Cassan, Michael Nemeth, Richard Bradley, Wei-Tien Chang, Nathan P Charlton, Jonathan L Epstein, Aaron Orkin, Sakamoto Tetsuya the members of the International Liaison Committee on Resuscitation First Aid and Paediatric Life Support Task Forces include: Richard Aickin, Kee-Chong Ng, Jason Acworth, Dianne Atkins, Thomaz Bittencourt Couto, Anne-Marie Guerguerian, Monica Kleinman, Vinay Nadkarni, Gabrielle Nuthall, Yong-Kwang Gene Ong, Amelia Reis, Antonio Rodriguez-Nunez, Steve Schexnayder, Barney Scholefield, Janice Tijssen and Patrick Van de Voorde, Allan De Caen, Ian Maconochie. In addition, the following non-task force members are also acknowledged for their contributions: Emma-Lotta Saatela (Karolinska Institutet Library Information Specialist). Professor Edgar Dale and Dr Bronwyn Griffin for sharing research data enabling meta-analysis.
Methodological Preamble and Link to Published Systematic Review
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with a systematic review of duration of cooling with water for a thermal burn as a first aid intervention (Djärv, 2020, PROSPERO registration number: CRD42021180665). Evidence for adult and pediatric literature was sought and considered by the First Aid Task Force and the Pediatric Task Force respectively. All meta-analyses were done with unadjusted data.
Systematic Review
Therese Djärv, Matthew Douma, Tina Palmieri, Daniel Meyran, David Berry, David Kloeck, Jason Bendall, Laurie J Morrison, EuniceM. Singletary and David Zideman, Duration of cooling with water for thermalburns as a first aid intervention: A systematic review, Burns, (2021)doi:https://doi.org/10.1016/j.burns.2021.10.007
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Adults and children in first aid settings with a thermal burn.
Intervention: Active cooling using water as an immediate first aid intervention for 20 minutes or more duration.
Comparators: Active cooling using water as an immediate first aid intervention for any other duration.
Outcomes:
Primary outcomes:
Size (critical) – defined as percentage of total body surface area (TBSA) at any reported time point (continuous).
Depth (critical) – as reported in articles by authors in three or four categories and analyzed from the negative dichotomous outcome of full thickness depth (including deep dermal partial thickness).
Secondary outcomes:
Pain (important)- defined as any measurement of pain or administration of pain medications (continuous and/or categorized outcome).
Adverse outcomes (important) – defined as any reported adverse outcome and a priori identified hypothermia (dichotomous outcome; yes/no).
Wound healing (important) – defined as time to re-epithelization in days (continuous outcome).
Complications within 24 hours (important)- defined as organ dysfunction, ICU-care, infections (within seven days), bleeding, rhabdomyolysis as well as surgical procedures such as fasciotomy and escharotomy.
It is anticipated that studies might not report the outcome `complications` within the 24-hour time frame. Since the PICOST is on a prehospital intervention, this time frame is considered appropriate to avoid including complications that are likely attributed to burn treatment, such as fluid overload or sepsis.
It is also anticipated that the reporting of complications varies between studies and that a meta-analysis might only be dichotomous (yes/no). We will provide a narrative summary of rates for each of these complications as defined.
Study Designs: Included: Randomized controlled trials (RCTs) and non-randomized studies (non-randomized controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) were eligible for inclusion. Excluded: Animal studies, case series, unpublished studies, conference abstracts and trial protocols were excluded.
Timeframe: All years and all languages were included as long as there was an English abstract; unpublished studies (e.g., conference abstracts, trial protocols) were excluded. Literature search updated to August 6, 2020 and re-run on 11 February 2021.
PROSPERO Registration CRD42021180665
Risk of bias and certainty of the evidence
Confidence in the estimate of effect, for the outcomes evaluated, was decreased owing to serious risk of bias and indirectness. The risk of bias was assessed for the critical outcomes of the size of burn and its depth. The estimate of certainty was decreased because of risk of bias and, for depth, due to inconsistency. Firstly, since all included studies were from one continent, we have to assume some geographic bias. Secondly, bias from confounding by indication was identified, whereby the duration of cooling may have been affected by the initial size or depth of the burn. Thirdly, selection bias and/or referral bias, whereby more severe cases or where the initial treatment was less effective, would probably be transferred to a burn center and, therefore, more likely to be captured in the dataset. No studies were undertaken in the first aid setting. Fourthly, the risk of bias including non-differential misclassification, namely difficulties in assessing the size and depth of a burn. We also identified indirectness as a result of the lack of objective measurement of the duration of cooling, the sparse outcome reporting on the adverse event of hypothermia, as well as the patient-centred outcome of pain relief. An insufficient number of studies were included to generate funnel plots to judge publication bias.
Consensus on Science
- In all, four observational studies together enrolling 5978 adults and children, all from Australia, were identified {Cuttle 2009 1028; Fein 2014 609; Griffin 2020 75; Wood 2016 11}.
- For the critical outcome of burn size, we identified very low certainty of evidence (downgraded for risk of bias and indirectness) from three observational studies enrolling a total of 4616 adults and children, evaluating burn size as a percentage of TBSA {Fein 2014 609; Griffin 2020 75; Wood 2016 11}. In a meta-analysis of all three studies, a difference could not be demonstrated in burn size for burns cooled for 20 minutes or more compared with burns cooled for less than 20 minutes (Standardized Mean Difference [SMD] -0.05; 95% CI, -0.15 – 0.04, I2=35%).
- For the critical outcome of any degree of a full thickness depth burn (yes/no), defined as deep dermal or full thickness burns, we identified very low certainty evidence (downgraded for risk of bias, inconsistency, indirectness and imprecision) from two observational studies enrolling a total of 4409 adults and children {Griffin 2020 75; Wood 2016 11}. Significant heterogeneity limited meta-analysis, therefore, the overall direction of effect could not be determined and effect estimates were used to illustrate effect range as the synthesis method. In the cohort study in children {Griffin 2020 75}, the result was in favour of cooling for less than 20 minutes compared with cooling for 20 minutes or more (RR 0.90; 95% CI 0.83-0.97). However, in the study on adults {Wood 2016 11}, the result was opposite, i.e. in favour of cooling for 20 minutes or more over cooling for less than 20 minutes (RR 1.11, 95% CI 1.00-1.22).
- Two observational studies of very low certainty evidence (downgraded due to risk of bias and indirectness) enrolling a total of 2491 children, assessed the important outcome of wound healing, defined as days to re-epithelialisation in non-grafted patients {Cuttle 2009 1028; Griffin 2020 75}. In a meta-analysis, a difference could not be demonstrated in days to re-epithelialisation for burns cooled for 20 minutes or more when compared with burns cooled for less than 20 minutes (SMD 0.01; 95% CI, -0.08 – 0.11, I2=0%).
- For the important outcome of complications, we found very low certainty evidence (downgraded for risk of bias and indirectness) in three observational studies enrolling a total of 4620 adults and children {Cuttle 2009 1028; Griffin 2020 75; Wood 2016 11} reporting the need for skin grafting. A meta-analysis did not demonstrate any difference in the need for skin grafting for burns cooled for 20 minutes or more when compared with burns cooled for less than 20 minutes (RR, 1.37; 95% CI, 0.61 – 3.08, I2=95).
- For the important outcome of pain, one observational study enrolling 117 children less than five years of age {Fein 2014 609} provided information on cooling duration in 24/117 (21%) children. A proxy for pain was the administration of an analgesic. Our analysis of unpublished data revealed that the majority of these children (57-59%) received analgesics such as paracetamol and/or morphine, administrated by paramedics (unknown administration route) with no obvious difference in pain scores between those cooled for less than 20 minutes and those cooled for 20 minutes or more.
- For the important outcome of complications and adverse events including hypothermia, one observational study (Fein 2014 609) was identified. Evaluation of unpublished data showed that out of 117 children with a thermal burn who were cooled with water as a first aid intervention, five children (4%), all under four years of age, developed hypothermia (34-36 degrees Celsius, tympanic assessment, n=4) or were visibly cold with shivering (n=1). Four out of five of these cases had received whole body cooling in a shower.
- Sensitivity analysis for cooling times between less than 10 minutes compared with both 10 minutes or more and 20 minutes or more showed no significant difference for any of the selected outcomes. There was no data for shorter durations, such as five minutes, compared with 10 minutes or longer durations than 20 minutes such as 30 minutes.
Treatment Recommendations
We recommend the immediate active cooling of thermal burns using running water as a first aid intervention for adults and children (strong recommendation, very low certainty evidence).
Because no difference in outcomes could be demonstrated with the different cooling durations studied, a specific duration of cooling cannot be recommended.
Young children with thermal burns that are being actively cooled with running water should be monitored for signs and/or symptoms of excessive body cooling (Good Practice Statement).
Technical remarks
The duration of cooling used in the reviewed studies varied from two minutes to 75 minutes, with 48% of patients cooled for 20 minutes or more.
The temperature of the water used and the cooling technique (running vs immersion) was noted in three studies {Fein 2014 609; Griffin 2020 75; Wood 2016 11} as ‘cool running water’ and in one study as ‘cold water’ {Cuttle 2009 1028}.
Among the included studies, we only identified one complication reported in several studies (need for skin-grafting, n=4620) and one complication identified in unpublished data (hypothermia and shivering, n=5) and neither was significantly associated with duration of cooling.
Justification and Evidence to Decision Framework Highlights
This topic was prioritized by the FA Task Force due to ongoing debate about the optimal duration of cooling of thermal burns. In 2015 the International Liaison Committee on Resuscitation (ILCOR) published a consensus on science and treatment recommendation (CoSTR) {Singletary 2015 S269; Zideman 2015 e225} with a strong recommendation for active cooling with running water treatment of thermal burns by first aid providers. It was noted in the Task Force insights of this CoSTR that the studies included used different methods for cooling (water, gel pads) with varying temperatures, and the literature suggested that active cooling with running water should take place as soon as possible for a minimum of 10 minutes. This led to published criticism of the 10-minute minimum and proposed instead a 20-minute minimum duration of cooling {Goodwin 2016 1148; Walsh 2016 99} based on expert opinion and evidence from animal studies {Bartlett 2008 828; Cuttle 2008 626; Cuttle 2010 673}. Recent national guidelines identified the lack of evidence as exemplified by the British National Institute for Health and Care Excellence (NICE) statement in their first aid guidelines (National Institute for Health 2020 webpage) with advice based mainly on expert opinions versus scientific evidence. The ILCOR First Aid Task Force sought to conduct a rigorous systematic review under the direction of expert systematic reviewers and with input from internationally recognized burns experts.
In making these recommendations, the FA Task Force considered the following:
- Although several large human studies were identified, the evidence was found to be inconclusive to either support or to refute the use of one duration of cooling with running water compared with another. Therefore, from an evidence-based perspective, the optimal duration for cooling of thermal burns with water as a first aid intervention, and the optimal technique (running water versus immersion) remains unknown.
- Very low certainty evidence failed to show a benefit in selected outcomes for a cooling duration of less than 20 minutes compared with cooling for 20 minutes or more. Likewise, we found no difference in outcome between less than 10 minutes compared to either 10 minutes or more or 20 minutes or more.
- This treatment recommendation is minimally changed from 2015. In making a strong recommendation for immediate cooling with water despite very low certainty evidence, the Task Force acknowledge that cooling with running water has previously been proved beneficial when compared with not cooling or compared with other methods of cooling in several different study designs; an animal study {Cuttle 2010 673}, an experimental study {Wright 2019 1472}, observational human studies {Cuttle 2009 1028; Tung 2005 12} and in one randomized human study {Cho 2017 502}. Guidelines might need to state a reasonable minimum cooling time suitable for the environment and epidemiology of burns in a specific geographic area.
- In Task Force discussions, it was the consensus opinion that the optimal duration of cooling may not be a rigid time but rather influenced by the burn location, the size and depth of the burn as well as the temperature of the water used for cooling. For example, more severe / extensive / painful burns might be deemed to require longer durations of cooling to observe a beneficial effect.
- The Task Force discussed the effect of cooling on pain in superficial and partial thickness burns. Since cooling is thought to relieve pain it is possible that first aid providers may cool a burn until the pain has been relieved rather than for a specific duration of time. We did not have enough data to support this theory or a recommendation.
- In burn research, the size of the burn is an essential outcome. The inclusion of the outcome of burn size was, a priori, deemed to be problematic in the ILCOR First Aid Task Force discussions. In first aid settings it is unreasonable to assume that either surface area or depth of a burn could or should be assessed before starting of cooling. It is plausible that a first aid provider may consider cooling a larger burn for a longer duration of time. A scatterplot comparing burn TBSA and duration of cooling suggests that larger burns induce longer cooling durations.
- RCTs are needed comparing different durations of cooling using running water versus immersion water with similar temperatures.
- Future studies should focus on information on who performed the cooling, such as self-aid or bystander (very early), emergency medical service providers (early), an emergency department or a burn centre (late) in order to better assess the clinical effectiveness of cooling strategies. Further, what is the optimal duration of cooling for minor burns that do not need assessment in burn centres or by advanced care providers?
- All included studies were from one geographical region, Australia, and all were completed in burn centres. Studies evaluating the duration of cooling with running water as a first aid intervention are needed from other continents and geographical regions.
- Additional research is needed to help identify alternative optimal cooling techniques when water is not available.
- Could pain relief with cooling of burns be a marker for appropriate duration of cooling of superficial burns?
- Do circumstances such as environment, type and location of burn change the time needed to cool a thermal burn?
- A concern was raised that cooling of burns in young children might result in hypothermia or shivering. This complication was identified in 5/117 children under 4 years of age, particularly following use of full body showering for cooling. Even a short cooling duration, especially if full-body cooling is used may result in hypothermia or shivering. This suggests the need for close monitoring in small children to minimize the risk of hypothermia.
- The review further stresses the poor compliance to the recommended duration of cooling of burns as directed in current guidelines. In total, out of 5978 causalities with a reported duration of cooling, 2893 (47%) reported a cooling duration in line with current local guidelines (20 minutes or more) {HealthDirect 2020 webpage} and 3600 (60%) reported a cooling duration of 10 minutes or more. The Task Force discussed how the compliance to guidelines might be affected by recommending a shorter or longer duration of cooling. It is possible that recommending a shorter duration may increase compliance but conversely it could shorten the cooling duration further.
Knowledge Gaps
Attachment
Et D-FA770-Duration-of-cooling-for-thermal-burn
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