Management of multiple frostbite casualties at a burn center: San Antonio, Texas, 12-20 February 2021.

BACKGROUND: Frostbite is an insidious disease that normally affects people of cold climates. Winter Storm Uri, which occurred from February 12-20, 2021, created unique metrological conditions for Texas. It caused prolonged sub-freezing temperatures and led to rolling blackouts, affecting 2.8 million Texans including 300,000 people in San Antonio. We report 13 frostbite patients admitted to one burn center during this event. OBJECTIVE: We aimed to determine the at-risk population for frostbite, to categorize their injury severity, and to describe their treatment. A secondary aim was to describe the rehabilitation management of these patients. METHODS: This is a single-center retrospective study. Each patient's injuries were assessed by a topographical grading system. Comparisons were made among those who were admitted to the intensive care unit (ICU), admitted to the progressive care unit (PCU), and treated as outpatients. RESULTS: Thirteen patients were identified. Ten (76.9 %) considered themselves homeless, and 9 (69.2 %) were directly exposed to the elements. The median delay between time of injury and presentation to a medical facility was 3 days (IQR 1-6). Only 3 patients presented to a medical facility within 24 h. Six (46 %) sustained grade 2 injuries, 2 (15 %) sustained grade 3 injuries, and 5 (38%) sustained grade 4 injuries. Only one patient met criteria to receive tissue plasminogen activator (tPA), which was discontinued due to hematochezia. Patients admitted to the ICU, when compared to patients admitted to the ward, had a longer length of stay (median 73 days v. 12 days, p = 0.0215), and required more amputations at below-the-knee or higher levels (3 v. 0, p-value 0.0442). CONCLUSION: In a region unaccustomed and perhaps unprepared to deal with winter storms, the population is particularly vulnerable to frostbite. Lack of awareness of frostbite injuries likely led to the delay in the presentation of patients, which prevented the timely use of tPA. Increasing public awareness may increase readiness.

Safety of Early Postoperative Range of Motion in Burn Patients With Newly Placed Hand Autografts: A Pilot Study.

Patients who suffer hand burns are at a high contracture risk, partly due to numerous cutaneous functional units, or contracture risk areas, located within the hand. Patients who undergo split-thickness skin grafting are often immobilized postoperatively for graft protection. Recent practice at our burn center includes an early range of motion (EROM) following hand grafting to limit unnecessary immobilization. The purpose of this study was to determine whether EROM is safe to perform after hand grafting and if there is any clinical benefit. This retrospective, matched case-control study of adults compared patients who received EROM to subjects who received the standard 3 to 5 days of postoperative immobilization. Patients were evaluated for graft loss and range of motion. Seventy-one patients were included in this study: 37 EROM patients and 34 matched controls. Six patients experienced minor graft loss, three of these were not attributable to EROM. All graft loss was less than 1 cm and none required additional surgery. Significantly more patients who received EROM achieved full-digital flexion by the first outpatient visit (25/27 = 92.6% vs 15/22 = 68.2%; P = .028). Performing EROM does not cause an increase in graft loss. All areas of graft loss from the EROM group healed without intervention. There appears to be a benefit to EROM since there was a significant improvement in the patients' ability to make a full fist at initial outpatient follow-up. Additional prospective analysis is needed to examine the true clinical utility of EROM in the hand and other contracture-prone areas.

Quantifying the effects of wound healing risk and potential on clinical measurements and outcomes of severely burned patients: A data-driven approach.

INTRODUCTION: Given recent advances in computational power, the goal of this study was to quantify the effects of wound healing risk and potential on clinical measurements and outcomes of severely burned patients, with the hope of providing more insight on factors that affect wound healing. METHODS: This retrospective study involved patients who had at least 10% TBSA% "burned" and three burn mappings each. To model risk to wounds, we defined the variable θ, a hypothetical threshold for TBSA% "open wound" used to demarcate "low-risk" from "high-risk" patients. Low-risk patients denoted those patients whose actual TBSA% "open wound" ≤θ, whereas high-risk patients denoted those patients whose actual TBSA% "open wound" >θ. To consider all possibilities of risk, 100 sub analyses were performed by (1) varying θ from 100% to 1% in decrements of 1%, (2) grouping all patients as either "low-risk" or "high-risk" for each θ, and (3) comparing all means and deviations of variables and outcomes between the two groups for each θ. Hence, this study employed a data-driven approach to capture trends in clinical measurements and outcomes. Plots and tables were also obtained. RESULTS: For 303 patients, median age and weight were 43 [29-59] years and 85 [72-99]kg, respectively. Mean TBSA% "burned" was 25 [17-39] %, with a full-thickness burn of 4 [0-15] %. Average crystalloid volumes were 4.25±2.27mL/kg/TBSA% "burned" in the first 24h. Importantly, for high-risk patients, decreasing θ was matched by significant increases in PaO2-FiO2 ratio, platelet count, Glasgow coma score (GCS), and MAP. On the other hand, increasing their risk θ was also matched by significant increases in creatinine, bilirubin, lactate, blood, estimated blood loss, and 24-h and total fluid volumes. As expected, for low-risk patients, clinical measurements were more stable, despite decreasing or increasing θ. At a θ of 80%, statistical tests indicated much disparity between high-risk and low-risk patients for TBSA% "burned", full thickness burn, bilirubin (1.66±1.16mg/dL versus 0.83±0.65mg/dL, p=0.005), GCS (7±2 versus 12±3, p<0.001), MAP (42±22mm Hg versus 59±22mm Hg, p=0.004), 24-h blood, estimated blood loss, 24-h fluid, total fluid, and ICU length of stay (81±113 days versus 24±27 days, p=0.002). These differences were all statistically significant and remained significant down to θ=10%. CONCLUSION: Wound healing risk and potential may be forecasted by many different clinical measurements and outcomes and has many implications on multi-organ function. Future work will be needed to further explain and understand these effects, in order to facilitate development of new predictive models for wound healing.

Relationship Between Burn Wound Location and Outcomes in Severely Burned Patients: More Than Meets the Size.

We hypothesized that burn location plays an important role in wound healing, mortality, and other outcomes and conducted the following study to test this multifold hypothesis. We conducted a study to retrospectively look at patients with burns ≥10% TBSA. Demographics, TBSA, partial/full thickness burns (PT/FT) in various wound locations, fluids, inhalation injury, mortality, ICU duration, and hospital duration were considered. Initial wound healing rates (%/d) were also calculated as a slope from the time of the first mapping of open wound size to the time of the third mapping of open wound size. Multivariate logistic regression and operating curves were used to measure mortality prediction performance. All values were expressed as median [interquartile range]. The mortality rate for 318 patients was 17% (54/318). In general, patients were 43 years [29, 58 years] old and had a TBSA of 25% [17, 39%], PT of 16% [10, 25%], and FT of 4% [0, 15%]. Between patients who lived and did not, age, TBSA, FT, 24-hour fluid, and ICU duration were statistically different (P < .001). Furthermore, there were statistically significant differences in FT head (0% [0, 0%] vs 0% [0, 1%], P = .048); FT anterior torso (0% [0, 1%] vs 1% [0, 4%], P < .001); FT posterior torso (0% [0, 0%] vs 0% [0, 4%], P < 0.001); FT upper extremities (0% [0, 3%] vs 2% [0, 11%], P < .001); FT lower extremities (0% [0, 2%] vs 6% [0, 17%], P < .001); and FT genitalia (0% [0, 0%] vs 0% [0, 2%], P < .001). Age, presence of inhalation injury, PT/FT upper extremities, and FT lower extremities were independent mortality predictors and per unit increases of these variables were associated with an increased risk for mortality (P < .05): odds ratio of 1.09 (95% confidence interval [CI] = 1.61-1.13; P < .001) for mean age; 2.69 (95% CI = 1.04-6.93; P = .041) for inhalation injury; 1.14 (95% CI = 1.01-1.27; P = .031) for mean PT upper extremities; 1.26 (95% CI = 1.11-1.42; P < .001) for mean FT upper extremities; and 1.07 (95% CI = 1.01-1.12; P = .012) for mean FT lower extremities. Prediction of mortality was better using specific wound locations (area under the curve [AUC], AUC of 0.896) rather than using TBSA and FT (AUC of 0.873). Graphs revealed that initial healing rates were statistically lower and 24-hour fluids and ICU length of stay were statistically higher in patients with FT upper extremities than in patients without FT extremities (P < .001). Burn wound location affects wound healing and helps predict mortality and ICU length of stay and should be incorporated into burn triage strategies to enhance resource allocation or stratify wound care.

Predicting wound healing rates and survival with the use of automated serial evaluations of burn wounds.

Healing of burn wounds is necessary for survival; however tracking progression or healing of burns is an inexact science. Recently, the relationship of mortality and wound healing has been documented with a software termed WoundFlow. The objective of the current study was to confirm various factors that impact burn wound healing, as well as to establish a timeline and rate of successful healing. A retrospective analysis was performed on adults (n=115) with at least 20% TBSA burn that had at least two computer-based wound mappings. The % open wound (%OW) was calculated over time to document healing trajectory until successful healing or death. Only 2% of patients in the group with successful wound healing died. A decrease in the %OW of 0.8 (IQR: 0.7-1.1) was associated with survival. Disparities in wound healing trajectories between survivors and non-survivors were distinguishable by 2weeks post-injury (P<0.05). When %TBSA was stratified by decile, the 40-49% TBSA group had the highest healing rate. Taken together, the data indicate that wound healing trajectory (%OW) varies with injury severity and survival. As such, automated mapping of wound healing trajectory may provide valuable information concerning patient/prognosis, and may recommend early interventions to optimize wound healing.

Wound healing trajectories in burn patients and their impact on mortality.

The rate of wound healing and its effect on mortality has not been well described. The objective of this article is to report wound healing trajectories in burn patients and analyze their effects on in-hospital mortality. The authors used software (WoundFlow) to depict burn wounds, surgical results, and healing progression at multiple time points throughout admission. Data for all patients admitted to the intensive care unit with ≥ 20% TBSA burned were collected retrospectively. The open wound size (OWS), which includes both unhealed burns and unhealed donor sites, was measured. We calculated the rate of wound closure (healing rate), which we defined as the change in OWS/time. We also determined the time delay (DAYS) from day of burn until day on which there was a reduction in OWS < 10%. Data are medians [interquartile range]. There were 38 patients with complete data; 25 had documentation of successful healing (H), and 13 did not (NH). H differed from NH on age (38 years [32-57] vs 63 [51-74]), body mass index (27 [21-28] vs 32 [19-52]), 24-hour fluid resuscitation (12 L [10-16] vs 18 [15-20]), pressors during first 48 hours (72% vs 100%), use of renal replacement therapy (32% vs 92%), and mortality (4% vs 100%). Repeated measures analysis of covariance showed a significant difference between survivors and nonsurvivors on OWS as a function of time (P<.001). Patients with a positive healing rate (+2%/day) after postburn day 20 had 100% survival whereas those with a negative healing rate (-2%/day) had 100% mortality. For H patients, median DAYS was 41 (28-54); median DAYS/TBSA was 1.3 (1.0-1.9). Survivors had a 0.62% drop in OWS/day, or 4.3%/week. In this cohort of patients with ≥ 20% TBSA, there was a difference in mortality after postburn day 20, between patients with a positive healing rate (+2%/day, 100% survival) and those with a negative healing rate (-2%/day, 100% mortality, P < .05).