- Email: [email protected]
Reconsidering recommendations for blanket warming
LETTERS TO THE EDITOR
www.aornjournal.org
Reconsidering recommendations for blanket warming We commend AORN for publishing the Perioperative Standards and Recommended Practices,1 with recommended practices according to systematic literature searches and the highest level of evidence available. However, we are concerned about the evidence rating and supporting references for Statement V.e. in the “Recommended practices for a safe environment of care,”2(p226) which states the following: Warming cabinet or compartment temperatures used for blankets and other patient linens should not exceed 130 F (54.5 C). [Likely to be Effective] In one limited quality improvement project, blankets were warmed to 150 F (65.6 C) without harmful effects to the subjects, who were alert and not under the effects of any anesthetic agents.[3] However, this recommendation is based on stronger evidence that shows temperatures greater than 130 F (54.4 C) increase the potential for burns.[4,5] The two references cited as “stronger evidence” for potential for burns4,5 are both from the ECRI Institute. Neither reference contains evidence that dry cotton blankets cause thermal injury. One is an executive summary.4 The other document is a “Hazard Report”5 that describes warming a 1-L IV solution bag and placing it on a cotton surgical towel. Two studies that were not included in section V.e. of the “Recommended practices for a safe environment of care”2 provide supportive evidence for the thermal comfort and safety of blankets warmed in cabinet temperatures higher than 130 F (54.4 C). In 2012, Sutton et al6 published a study demonstrating the safety and thermal comfort of cotton blankets warmed at 155 F (68.3 C). Our 2013 study of blankets warmed at 130 F and 200 F (93.3 C)7 was not published when the 2013 edition of Perioperative Standards and Recommended Practices1 was released. We conducted a randomized,
prospective, comparative, descriptive study of blankets warmed in cabinets set at 130 F (54.4 C) and 200 F (93.3 C). We measured skin temperatures and thermal comfort before and at timed intervals after application of blankets from the two cabinet warming temperatures. The highest individual skin temperature was 99.7 F (37.6 C) 30 seconds after blanket placement. This temperature is well below the skin temperature required for thermal injury, as noted by ECRI Institute5(p2): According to published research, most human skin can tolerate exposure to a temperature of 43 C (110 F) for long durations (about six hours) without thermal injury.[8] In our study,7 no skin temperature was higher than 97.3 F (36.3 C) 10 minutes after blanket application, and the blankets lost heat quickly over time. Participants preferred blankets warmed in cabinets set at 200 F (93.3 C). Based on our research7 and others’,6 we recommend that AORN reconsider “Recommended practices for a safe environment of care” Recommendation V.e. AORN has a history of commitment to evidence-based practice. Recommendations for warming blankets should not be confused with warnings about warming solutions. The AORN blanket warming cabinet temperature recommendations should reflect current evidence and include research about dry cotton blankets, scientific principles of heat transfer and heat loss, and patient preferences for warmer blankets. ELIZABETH MORSE BSN, RN, CPAN SURGICAL SERVICES CLINICAL EDUCATOR CENTER FOR ADVANCING PROFESSIONAL PRACTICE TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX AORN Journal j 353
March 2014 Vol 99 No 3
THERESA SANDS BSN, RN, CNOR OPERATING ROOM, CLINICAL NURSE PERIOPERATIVE SERVICES TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX PATRICIA KELLY DNP, APRN, CNS, AOCN RESEARCH/EVIDENCE-BASED PRACTICE/ GENOMICS CENTER FOR ADVANCING PROFESSIONAL PRACTICE TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX MARY KROGH RN, CPAN, PACU CLINICAL NURSE PERIANESTHESIA SERVICES TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX http://dx.doi.org/10.1016/j.aorn.2014.01.005
References 1. Perioperative Standards and Recommended Practices. Denver, CO: AORN, Inc; 2013. 2. Recommended practices for a safe environment of care. In: Perioperative Standards and Recommended Practices. Denver, CO: AORN, Inc; 2013:217-242. 3. Bujdoso PJ. Blanket warming: comfort and safety. AORN J. 2009;89(4):717-722. 4. ECRI Institute. Warming cabinets. Oper Room Risk Manag. 2010;2(Surgery 7). 5. ECRI Institute. Limiting temperature settings on blanket and solution warming cabinets can prevent patient burns. Health Devices. 2005;34(5):168-171. 6. Sutton LT, Baker FS, Faile NJ, Tavakoli A. A quasiexperimental study examining the safety profile and comfort provided by two different blanket temperatures. J Perianesth Nurs. 2012;27(3):181-192. 7. Kelly PA, Cooper SK, Krogh ML, et al. Thermal comfort and safety of cotton blankets warmed at 130 F and 200 F. J Perianesth Nurs. 2013;28(6):337-346. 8. Moritz AR, Henriques FC Jr. Studies of thermal injury: II: the relative importance of time and surface temperature in the causation of cutaneous burns. Am J Pathol. 1947;23(5): 695-720.
Author response. The AORN recommended practices (RP) documents are based on the highest level of evidence available at the time the document is developed or revised. The review, revision, and 354 j AORN Journal
LETTERS TO THE EDITOR final publication of AORN RP documents is a lengthy process, requiring several months to complete. The review process begins with a search of the literature in an effort to find current published research and other nonresearch evidence related to the topic at hand. The “Recommended practices for a safe environment of care”1 review process began early in 2011. The AORN medical librarian conducted a systematic literature search of the databases MEDLINEÒ, CINAHLÒ, ScopusÒ, and Cochrane Database of Systematic Reviews for meta-analyses, randomized and nonrandomized trials and studies, systematic and nonsystematic reviews, and opinion documents and letters. The search was limited to articles published in English and between the years 2005 and 2011. The recommendation related to the temperature of blanket warmers is based on the evidence that was published and available at the time of the review of the “Recommended practices for a safe environment of care.”1 Had the commendable research articles by Kelly et al2 and Sutton et al3 been published within the time frame of the literature search, this evidence would certainly have been identified and included in the literature review and evidence appraisal process. Thank you for bringing this research to our attention; we will be reviewing this and other evidence, and will review the “Recommended practices for a safe environment of care”1 document, which is currently scheduled for 2014. AORN encourages perioperative RNs to use evidence-based practice as the foundation upon which to base patient care. Keeping current on all the rapidly emerging evidence is a daunting endeavor, and AORN is dedicated to providing support through each of the documents in the Perioperative Standards and Recommended Practices.4 Although we review and update the RP documents approximately every three to five years, new evidence will emerge after a new or revised RP document has been published. Compliance with the AORN recommended practices is voluntary. As new compelling evidence
www.aornjournal.org
Reconsidering recommendations for blanket warming We commend AORN for publishing the Perioperative Standards and Recommended Practices,1 with recommended practices according to systematic literature searches and the highest level of evidence available. However, we are concerned about the evidence rating and supporting references for Statement V.e. in the “Recommended practices for a safe environment of care,”2(p226) which states the following: Warming cabinet or compartment temperatures used for blankets and other patient linens should not exceed 130 F (54.5 C). [Likely to be Effective] In one limited quality improvement project, blankets were warmed to 150 F (65.6 C) without harmful effects to the subjects, who were alert and not under the effects of any anesthetic agents.[3] However, this recommendation is based on stronger evidence that shows temperatures greater than 130 F (54.4 C) increase the potential for burns.[4,5] The two references cited as “stronger evidence” for potential for burns4,5 are both from the ECRI Institute. Neither reference contains evidence that dry cotton blankets cause thermal injury. One is an executive summary.4 The other document is a “Hazard Report”5 that describes warming a 1-L IV solution bag and placing it on a cotton surgical towel. Two studies that were not included in section V.e. of the “Recommended practices for a safe environment of care”2 provide supportive evidence for the thermal comfort and safety of blankets warmed in cabinet temperatures higher than 130 F (54.4 C). In 2012, Sutton et al6 published a study demonstrating the safety and thermal comfort of cotton blankets warmed at 155 F (68.3 C). Our 2013 study of blankets warmed at 130 F and 200 F (93.3 C)7 was not published when the 2013 edition of Perioperative Standards and Recommended Practices1 was released. We conducted a randomized,
prospective, comparative, descriptive study of blankets warmed in cabinets set at 130 F (54.4 C) and 200 F (93.3 C). We measured skin temperatures and thermal comfort before and at timed intervals after application of blankets from the two cabinet warming temperatures. The highest individual skin temperature was 99.7 F (37.6 C) 30 seconds after blanket placement. This temperature is well below the skin temperature required for thermal injury, as noted by ECRI Institute5(p2): According to published research, most human skin can tolerate exposure to a temperature of 43 C (110 F) for long durations (about six hours) without thermal injury.[8] In our study,7 no skin temperature was higher than 97.3 F (36.3 C) 10 minutes after blanket application, and the blankets lost heat quickly over time. Participants preferred blankets warmed in cabinets set at 200 F (93.3 C). Based on our research7 and others’,6 we recommend that AORN reconsider “Recommended practices for a safe environment of care” Recommendation V.e. AORN has a history of commitment to evidence-based practice. Recommendations for warming blankets should not be confused with warnings about warming solutions. The AORN blanket warming cabinet temperature recommendations should reflect current evidence and include research about dry cotton blankets, scientific principles of heat transfer and heat loss, and patient preferences for warmer blankets. ELIZABETH MORSE BSN, RN, CPAN SURGICAL SERVICES CLINICAL EDUCATOR CENTER FOR ADVANCING PROFESSIONAL PRACTICE TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX AORN Journal j 353
March 2014 Vol 99 No 3
THERESA SANDS BSN, RN, CNOR OPERATING ROOM, CLINICAL NURSE PERIOPERATIVE SERVICES TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX PATRICIA KELLY DNP, APRN, CNS, AOCN RESEARCH/EVIDENCE-BASED PRACTICE/ GENOMICS CENTER FOR ADVANCING PROFESSIONAL PRACTICE TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX MARY KROGH RN, CPAN, PACU CLINICAL NURSE PERIANESTHESIA SERVICES TEXAS HEALTH PRESBYTERIAN HOSPITAL DALLAS DALLAS, TX http://dx.doi.org/10.1016/j.aorn.2014.01.005
References 1. Perioperative Standards and Recommended Practices. Denver, CO: AORN, Inc; 2013. 2. Recommended practices for a safe environment of care. In: Perioperative Standards and Recommended Practices. Denver, CO: AORN, Inc; 2013:217-242. 3. Bujdoso PJ. Blanket warming: comfort and safety. AORN J. 2009;89(4):717-722. 4. ECRI Institute. Warming cabinets. Oper Room Risk Manag. 2010;2(Surgery 7). 5. ECRI Institute. Limiting temperature settings on blanket and solution warming cabinets can prevent patient burns. Health Devices. 2005;34(5):168-171. 6. Sutton LT, Baker FS, Faile NJ, Tavakoli A. A quasiexperimental study examining the safety profile and comfort provided by two different blanket temperatures. J Perianesth Nurs. 2012;27(3):181-192. 7. Kelly PA, Cooper SK, Krogh ML, et al. Thermal comfort and safety of cotton blankets warmed at 130 F and 200 F. J Perianesth Nurs. 2013;28(6):337-346. 8. Moritz AR, Henriques FC Jr. Studies of thermal injury: II: the relative importance of time and surface temperature in the causation of cutaneous burns. Am J Pathol. 1947;23(5): 695-720.
Author response. The AORN recommended practices (RP) documents are based on the highest level of evidence available at the time the document is developed or revised. The review, revision, and 354 j AORN Journal
LETTERS TO THE EDITOR final publication of AORN RP documents is a lengthy process, requiring several months to complete. The review process begins with a search of the literature in an effort to find current published research and other nonresearch evidence related to the topic at hand. The “Recommended practices for a safe environment of care”1 review process began early in 2011. The AORN medical librarian conducted a systematic literature search of the databases MEDLINEÒ, CINAHLÒ, ScopusÒ, and Cochrane Database of Systematic Reviews for meta-analyses, randomized and nonrandomized trials and studies, systematic and nonsystematic reviews, and opinion documents and letters. The search was limited to articles published in English and between the years 2005 and 2011. The recommendation related to the temperature of blanket warmers is based on the evidence that was published and available at the time of the review of the “Recommended practices for a safe environment of care.”1 Had the commendable research articles by Kelly et al2 and Sutton et al3 been published within the time frame of the literature search, this evidence would certainly have been identified and included in the literature review and evidence appraisal process. Thank you for bringing this research to our attention; we will be reviewing this and other evidence, and will review the “Recommended practices for a safe environment of care”1 document, which is currently scheduled for 2014. AORN encourages perioperative RNs to use evidence-based practice as the foundation upon which to base patient care. Keeping current on all the rapidly emerging evidence is a daunting endeavor, and AORN is dedicated to providing support through each of the documents in the Perioperative Standards and Recommended Practices.4 Although we review and update the RP documents approximately every three to five years, new evidence will emerge after a new or revised RP document has been published. Compliance with the AORN recommended practices is voluntary. As new compelling evidence