1
|
Smith RD, Carney BC, Garg G, Monger KW, Prindeze NJ, Shupp JW, Moffatt LT. Modeling Burn Progression Using Comb Burns: The Impact of Thermal Contact Duration on Model Outcomes. J Surg Res 2020; 260:155-162. [PMID: 33340869 DOI: 10.1016/j.jss.2020.11.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/02/2020] [Accepted: 11/15/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND Burn progression is a phenomenon that remains poorly characterized. The mechanisms of burn conversion are not completely understood, and consequently, both predictive diagnostic tools and interventions are limited. The rat comb burn model is a commonly used approach to study horizontal burn conversion. However, there is significant variability in how the model is performed. Skin contact duration, comb device heating method, comb heating duration, amount of pressure applied, the weight of the comb, and associated depth of burn are all variables that are heterogeneous in studies utilizing the model. MATERIALS AND METHODS Here, contact duration was examined to determine the impact the duration of burn delivery has on the conversion of interspaces in this model. Data from multiple experiments consisting of 10, 15, 20, 30, 40, and 45 s comb burns were compiled and assessed. Burns were made using combs heated in a 100°C dry bath and then monitored for 2 d. Interspace viability was assessed by digital and laser doppler imaging and biopsy procurement. RESULTS Laser Doppler Imaging and viable interspace measurements showed that as burn duration increased, the percentage of the viable interspace and interspace perfusion decreased. Additionally, a contact time of 30 s or greater was required to result in 100% interspace conversion. CONCLUSIONS These results demonstrate a need to better characterize and potentially standardize the rat comb burn model to reduce variation and maintain it as a valuable tool for controlled studies of the pathophysiology of burn wound progression.
Collapse
Affiliation(s)
- Robert D Smith
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia
| | - Bonnie C Carney
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia; Department of Biochemistry and Molecular Biology, Georgetown University, Washington, District of Columbia
| | - Gaurav Garg
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia; Department of Surgery, MedStar Washington Hospital Center and MedStar Georgetown University Hospital, Washington, District of Columbia
| | - Kyle W Monger
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia
| | - Nicholas J Prindeze
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia; Department of Surgery, MedStar Washington Hospital Center and MedStar Georgetown University Hospital, Washington, District of Columbia
| | - Jeffrey W Shupp
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia; Department of Biochemistry and Molecular Biology, Georgetown University, Washington, District of Columbia; The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, District of Columbia; Department of Surgery, Georgetown University School of Medicine, Washington, District of Columbia.
| | - Lauren T Moffatt
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, District of Columbia; Department of Biochemistry and Molecular Biology, Georgetown University, Washington, District of Columbia; Department of Surgery, Georgetown University School of Medicine, Washington, District of Columbia
| |
Collapse
|
2
|
Alkhalil A, Day A, Monger KW, Zhang J, Carney BC, Hoffman HN, Moffatt LT, Shupp JW. Hydroconductive and silver-impregnated foam dressings: a comparison. J Wound Care 2019; 26:S15-S22. [PMID: 28704172 DOI: 10.12968/jowc.2017.26.sup7.s15] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE As the number of commercially available wound dressings is increasing rapidly, it is important for clinicians to understand the strengths and limitations of each and to recognise relationships between wound type and dressing properties to obtain optimal healing results. Our aim is to test the antimicrobial activity of two dressings. METHOD A hydroconductive (HC) dressing and a silver-impregnated foam (SIF) dressing were compared for their potential to reduce the levels meticillin-resistant Staphylococcus aureus (MRSA). We also assessed MRSA-derived biologically active components in liquid or agar matrices, simplified models for heavily exuding or dry wounds respectively, and in an in vivo animal model with MRSA infected wounds. RESULTS In the agar model (dry wounds) both dressings showed a strong reduction in MRSA activities within 24 hours post-application. The antibacterial effects of the SIF dressing were more pronounced in the liquid model, however, at an increasing cytotoxic cost. In agreement with these in vitro results, assessment of dressings using an MRSA-infected wound in an rat model showed a decrease in MRSA which was significant 7 days post-burn and inoculation, with more compromised viability of MRSA. Dressings showed a similar capability to reduced and eliminate toxic shock syndrome toxin (TSST-1) at day 7 post-burn in the animal model but not at day 4, where the SIF dressing was more potent Conclusion: These results confirm the advantages of using silver in reducing bacterial load in wound treatment, except for conditions of highly exuding wounds where the cytotoxic properties of silver may offset these advantages and HC dressing use is more suitable.
Collapse
Affiliation(s)
- A Alkhalil
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - A Day
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - K W Monger
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - J Zhang
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - B C Carney
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - H N Hoffman
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - L T Moffatt
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US
| | - J W Shupp
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC, US.,The Burn Center, MedStar Washington Hospital Center, Washington, DC, US
| |
Collapse
|
3
|
Zeineddin A, McLawhorn MM, Ball RL, Luker J, Day A, Monger KW, Orfeo T, Brummel-Ziedins KE, Moffatt LT, Shupp JW. Chronology of Coagulopathy after Thermal Injury. J Am Coll Surg 2018. [DOI: 10.1016/j.jamcollsurg.2018.07.532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
4
|
Vigiola Cruz M, Carney BC, Luker JN, Monger KW, Vazquez JS, Moffatt LT, Johnson LS, Shupp JW. Plasma Ameliorates Endothelial Dysfunction in Burn Injury. J Surg Res 2018; 233:459-466. [PMID: 30502286 DOI: 10.1016/j.jss.2018.08.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/28/2018] [Accepted: 08/06/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND A complex inflammatory response mediates the systemic effects of burn shock. Disruption of the endothelial glycocalyx causes shedding of structural glycoproteins, primarily syndecan-1 (SDC-1), leading to endothelial dysfunction. These effects may be mitigated by resuscitative interventions. MATERIALS AND METHODS Sprague-Dawley rats were used to create small, medium, and large burns and uninjured controls. Three different intravenous resuscitation protocols were applied within each group: Lactated Ringer's (LR) alone, LR plus fresh frozen plasma (FFP), or LR plus albumin. Blood was serially collected, and plasma SDC-1 was quantified with enzyme-linked immunosorbent assay. In one cohort, Evan's Blue Dye (EBD) was administered and quantified in lung by spectrophotometry as a functional assay of vascular permeability. In a second cohort, intact SCD-1 was quantified by immunohistochemistry in lung tissue. Statistical analysis employed two-way analysis of variance with multiple comparisons and Student's t-test. RESULTS EBD extraction from lung was significantly greater with higher injury severity versus controls. Extraction decreased significantly in large-burn animals with addition of FFP to LR versus LR-only; addition of albumin to LR did not decrease EBD extraction. Plasma SCD-1 increased in injured animals compared with controls, and changes correlated with injury severity in all resuscitation groups (significance, P < 0.05). Lung SCD-1 staining reflected the results in the EBD assay. CONCLUSIONS Addition of FFP, not of albumin, to post-burn resuscitation diminishes vascular leakage associated with large burns. Addition of colloid does not affect SDC-1 shedding as measured in plasma. Ongoing work will further define pathophysiologic mechanisms and potential therapeutic interventions to mitigate injury and promote repair of the endothelial glycocalyx.
Collapse
Affiliation(s)
- Mariana Vigiola Cruz
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC; The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC; Department of Surgery, MedStar Georgetown University Hospital, Washington, DC
| | - Bonnie C Carney
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Jenna N Luker
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Kyle W Monger
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Juan Sebastian Vazquez
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC; The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC
| | - Lauren T Moffatt
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC; The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC
| | - Laura S Johnson
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC
| | - Jeffrey W Shupp
- Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC; The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC.
| |
Collapse
|