Akinori Osuka1, Takuma Ishihara2, Kentaro Shimizu3, Ayumi Shintani4, Hiroshi Ogura5, Masahi Ueyama6. 1. Department of Trauma, Critical Care Medicine and Burn Center, Japan Community Healthcare Organization Chukyo Hospital, 1-1-10 Sanjo, Minami-ku, Nagoya, Aichi 457-8510, Japan; Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15, Yamadaoka, Suita, 065-0871 Osaka, Japan. Electronic address: osuka-ngy@umin.ac.jp. 2. Department of Clinical Statistics, Osaka City University Graduate School of Medicine, 1-5-7, Asahimachi, Abeno-ku, Osaka 545-8586, Japan; Gifu University Hospital Innovative and Clinical Research Promotion Center, 1-1, Yanagido, 501-1194 Gifu, Japan. Electronic address: ishihara.takuma@med.osaka-cu.ac.jp. 3. Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15, Yamadaoka, Suita, 065-0871 Osaka, Japan. Electronic address: shimiken@hp-emerg.med.osaka-u.ac.jp. 4. Department of Clinical Statistics, Osaka City University Graduate School of Medicine, 1-5-7, Asahimachi, Abeno-ku, Osaka 545-8586, Japan. Electronic address: ayumi.shintani@gmail.com. 5. Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15, Yamadaoka, Suita, 065-0871 Osaka, Japan. Electronic address: ogura@hp-emerg.med.osaka-u.ac.jp. 6. Department of Trauma, Critical Care Medicine and Burn Center, Japan Community Healthcare Organization Chukyo Hospital, 1-1-10 Sanjo, Minami-ku, Nagoya, Aichi 457-8510, Japan. Electronic address: masashi-ueyama@chukyo.jcho.go.jp.
Abstract
BACKGROUND: Severely burned patients often suffer white blood cell and platelet drop following the injury. Though coagulopathy after burn injury have been reported, the association between leukopenia or thrombopenia and mortality is still unrevealed. To determine whether early drastic drops in white blood cells (WBCs) and platelets following injury can be prognostic markers in patients with major burns. METHODS: This is a retrospective cohort study setting in a single Burn Center in Japan. Data comprising patients' characteristics and blood cell counts (red blood cells [RBCs], WBCs including neutrophils, monocytes, and lymphocytes, and platelets) over the first 30 days after burn injury were serially collected from patients suffering major burn injury (≥20% TBSA) from January 1, 2006 to December 31, 2015. To determine blood cell counts affecting 60-day mortality, we used multivariable Cox proportional hazard analysis to assess associations between each blood cell count and mortality, adjusting for age and %TBSA as covariates, and evaluated predicted value of the hazard ratio (HR) of death. RESULTS: We enrolled 280 patients. Following burn injury, all blood cell counts were high at admission, then decreased. RBCs diminished progressively and plateaued 2 weeks after injury. WBCs decreased suddenly 2 days after injury, then increased and stabilized. Platelets decreased more rapidly than WBCs to their nadir at 3 days, then continually increased. After covariate adjustment, low RBCs from day 1 (HR: 0.566, 95% C.I. 0.423, 0.759) to day 5 (HR: 0.524, 95% C.I. 0.175, 0.576) were predictors of mortality. Neutrophil count was not a risk factor, but day 3 lymphocyte count (HR: 0.131, 95% C.I. 0.026, 0.646) and day 10 monocyte count (HR: 0.044, 95% C.I. 0.005, 0.396) were risk factors. Low platelet counts from day 3 (HR: 0.545, 95% C.I. 0.300, 0.981) to day 30 following injury were always a predictor of mortality. CONCLUSIONS: Early thrombopenia and lymphopenia were independent risk factors for 60-day mortality, and prolonged thrombopenia and monocytopenia were independent risk factors for mortality. These findings might shed light on mechanisms of immune response following severe burns.
BACKGROUND: Severely burned patients often suffer white blood cell and platelet drop following the injury. Though coagulopathy after burn injury have been reported, the association between leukopenia or thrombopenia and mortality is still unrevealed. To determine whether early drastic drops in white blood cells (WBCs) and platelets following injury can be prognostic markers in patients with major burns. METHODS: This is a retrospective cohort study setting in a single Burn Center in Japan. Data comprising patients' characteristics and blood cell counts (red blood cells [RBCs], WBCs including neutrophils, monocytes, and lymphocytes, and platelets) over the first 30 days after burn injury were serially collected from patients suffering major burn injury (≥20% TBSA) from January 1, 2006 to December 31, 2015. To determine blood cell counts affecting 60-day mortality, we used multivariable Cox proportional hazard analysis to assess associations between each blood cell count and mortality, adjusting for age and %TBSA as covariates, and evaluated predicted value of the hazard ratio (HR) of death. RESULTS: We enrolled 280 patients. Following burn injury, all blood cell counts were high at admission, then decreased. RBCs diminished progressively and plateaued 2 weeks after injury. WBCs decreased suddenly 2 days after injury, then increased and stabilized. Platelets decreased more rapidly than WBCs to their nadir at 3 days, then continually increased. After covariate adjustment, low RBCs from day 1 (HR: 0.566, 95% C.I. 0.423, 0.759) to day 5 (HR: 0.524, 95% C.I. 0.175, 0.576) were predictors of mortality. Neutrophil count was not a risk factor, but day 3 lymphocyte count (HR: 0.131, 95% C.I. 0.026, 0.646) and day 10 monocyte count (HR: 0.044, 95% C.I. 0.005, 0.396) were risk factors. Low platelet counts from day 3 (HR: 0.545, 95% C.I. 0.300, 0.981) to day 30 following injury were always a predictor of mortality. CONCLUSIONS: Early thrombopenia and lymphopenia were independent risk factors for 60-day mortality, and prolonged thrombopenia and monocytopenia were independent risk factors for mortality. These findings might shed light on mechanisms of immune response following severe burns.