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.
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.
Burns. 2019 Dec;45(8):1901-1907. doi: 10.1016/j.burns.2019.07.014. Epub 2019 Aug 2.
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.
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.
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.
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.
严重烧伤患者在受伤后常出现白细胞和血小板减少。尽管烧伤后凝血功能障碍已有报道，但白细胞减少或血小板减少与死亡率之间的关系尚未阐明。本研究旨在确定受伤后白细胞（WBC）和血小板的早期急剧下降是否可以作为大面积烧伤患者的预后标志物。
这是一项在日本单家烧伤中心进行的回顾性队列研究。本研究从 2006 年 1 月 1 日至 2015 年 12 月 31 日期间，连续收集了因大面积烧伤（≥20%TBSA）而入院的患者的特征和血液细胞计数（红细胞[RBC]、包括中性粒细胞、单核细胞和淋巴细胞在内的 WBC 以及血小板）的数据。为了确定影响 60 天死亡率的血液细胞计数，我们使用多变量 Cox 比例风险分析来评估每个血液细胞计数与死亡率之间的关联，将年龄和%TBSA 作为协变量进行调整，并评估死亡风险比（HR）的预测值。
本研究共纳入了 280 名患者。烧伤后，所有血液细胞计数在入院时均较高，然后逐渐下降。RBC 持续减少，伤后 2 周时达到平台期。WBC 在伤后 2 天突然下降，然后增加并稳定。血小板比 WBC 下降更快，在伤后 3 天达到最低点，然后持续增加。在协变量调整后，伤后第 1 天（HR：0.566，95%CI：0.423，0.759）至第 5 天（HR：0.524，95%CI：0.175，0.576）的 RBC 低水平是死亡的预测因素。中性粒细胞计数不是危险因素，但伤后第 3 天的淋巴细胞计数（HR：0.131，95%CI：0.026，0.646）和第 10 天的单核细胞计数（HR：0.044，95%CI：0.005，0.396）是危险因素。伤后第 3 天（HR：0.545，95%CI：0.300，0.981）至第 30 天的血小板计数低始终是死亡的预测因素。
早期血小板减少和淋巴细胞减少是 60 天死亡率的独立危险因素，而血小板减少和单核细胞减少持续时间长是死亡的独立危险因素。这些发现可能为严重烧伤后免疫反应的机制提供了线索。
