Analysis of changes in coagulation factors after postoperative blood loss in burn and non-burn patients

Burn-Induced Coagulopathies: a Comprehensive Review

Burn-induced coagulopathy is not well understood, and consensus on diagnosis, prevention, and treatments are lacking. In this review, literature on burn-induced (and associated) coagulopathy is presented along with the current understanding of the effects of burn injury on the interactions among coagulation, fibrinolysis, and inflammation in the acute resuscitative phase and reconstructive phase of care. The role of conventional tests of coagulopathy and functional assays like thromboelastography or thromboelastometry will also be discussed. Finally, reported methods for the prevention and treatment of complications related to burn-induced coagulopathy will be reviewed.

Relation between dynamic changes of platelet counts and 30-day mortality in severely burned patients

Thrombocytopenia is a common event in severely burned patients and associated with adverse outcome. The underlying relationship between the dynamic changes of platelet counts and mortality has not been well defined. We performed a 6-year retrospective chart of adult patients with a burn index of 50 or greater admitted to two burn centers and collected data on patient demographics, laboratory results, and patient outcomes. The mean daily increase in the platelet count (∆PC/∆t) from day 3 to day 10 was calculated, and 30-day mortality was determined. For the study, 141 survivors and 65 nonsurvivors were enrolled. The sequential changes in PCs presented a biphasic pattern after admission, with a slump to the nadir during the first 3 days and a subsequent recovery. With respect to 30-day mortality, compared with the AUC of APACHE-Ⅱ score (0.841), no significant difference was noted between ΔPC/ΔT and APACHE-Ⅱ score (p = 0.0648). The ΔPC/ΔT associated with the best discrimination between survivors and nonsurvivors was 20.57 × 10⁹/L due to the cutoff with optimal Youden index (0.453). By multiple logistic regression, ΔPC/ΔT ＜ 20.57 × 10⁹/L was one of the prognostic predictors of 30-day mortality. Furthermore, Kaplan-Meier estimates of hospital survival according to the size of ΔPC/ΔT revealed that a blunted increase with ΔPC/ΔT ＜ 20.57 × 10⁹/L was associated with increased 30-day mortality. A blunted daily increase in PCs, especially ΔPC/ΔT < 20.57 × 10⁹/L, is associated with increased 30-day mortality, which provides prognostic information for mortality risk assessment in severely burned patients.

Acute blood loss during burn and soft tissue excisions: An observational study of blood product resuscitation practices and focused review

BACKGROUND

Many military and civilian centers have shifted to a damage-control resuscitation approach, focused on providing oxygen-carrying capacity while simultaneously mitigating coagulopathy with a balanced ratio of platelets and plasma to red blood cells. It is unclear to what degree this strategy is used during burn or soft tissue excision. Here, we characterized blood product transfusion during burn and soft tissue surgery and reviewed the published literature regarding intraoperative coagulation changes. We hypothesized that blood product resuscitation during burn and soft tissue excision is not hemostatic and would be insufficient to address hemorrhage-induced coagulopathy.

METHODS

Consented adult patients were enrolled into an institutional review board-approved prospective observational study. Number, component type, volume, and age of the blood products transfused were recorded during burn excision/grafting or soft tissue debridement. Component bags (packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate) were collected, and the remaining sample was harvested from the bag and tubing. Aliquots of 1/1,000th the original volume of each blood product were obtained and combined, producing an amalgam sample containing the same ratio of product transfused. Platelet count, rotational thromboelastometry, and impedance aggregometry were measured. Significance was set at p < 0.05.

RESULTS

Amalgamated transfusate samples produced abnormally weak clots (p ≤ 0.001) particularly if they did not contain platelets. Clot strength (48.8 [2.6] mm; reference range, 49-71 mm) for platelet-containing amalgams was below the lower limit of the reference range despite platelet-red blood cell ratios greater than 1:1. Platelet aggregation was abnormally low; transfused platelets were functionally inferior to native platelets.

CONCLUSION

Our study and focused review demonstrate that further work is needed to fully understand the needs of patients undergoing tissue excision. The three studies reviewed and the results of our observational work suggest that coagulopathy and thrombocytopenia may contribute to intraoperative hemorrhage. Blood product resuscitation during burn and soft tissue excision is not hemostatic.

LEVEL OF EVIDENCE

Epidemiologic study, level V.

Time course of thrombocytes in burn patients and its predictive value for outcome

Thrombocytopenia is common in trauma and critically ill patients and is associated with a poor outcomes. The objective of this retrospective study was to investigate the course of thrombocyte concentration changes in burn patients, the influences of various factors on this course, and a possible predictive value of thrombocyte counts on outcome in 244 patients admitted to our burn centre. Their thrombocyte counts were obtained until 50 days after burn. Data on patient demographics, total percentage burned surface area (%TBSA), sepsis and mortality were collected. Multilevel multivariable analysis was performed to investigate the influence of the variables on the platelet course. Cox regression analysis was performed to analyse the predictive value of the variables for mortality. A distinct pattern of thrombocyte counts was observed, with a nadir at day 3 followed by a peak at day 15 and a temporary thrombocytosis. %TBSA and age (p<0.05) influence this course. The mean thrombocyte course of septic and non-surviving patients depicts a significant lower nadir. Furthermore, higher age, %TBSA and low thrombocyte counts at the peak are predictive for 50 day mortality (p<0.05). Platelets follow a distinct course after burn, influenced by %TBSA and age. These factors and a low thrombocyte peak count predict mortality.