Forsberg Ulf, Jonsson Per, Stegmayr Bernd
Department of Public Health and Clinical Medicine, Skelleftea Unit, Umea University, Umea, Sweden.
Unit of Medicine, Umeå University, Umeå, Sweden.
Clin Kidney J. 2022 Oct 6;16(1):159-166. doi: 10.1093/ckj/sfac217. eCollection 2023 Jan.
Larger volumes of accidental air infused during medical care may end up as emboli while microbubbles of air are supposed to be absorbed and cause no harm. The aim of this autopsy study was to investigate if microbubbles of air accidently entering the bloodline may be detected as microemboli (ME) in tissue such as lungs, brain and heart. If so, do differences in prevalence exist between haemodialysis (HD) and amyotrophic lateral sclerosis (ALS) patients.
Included were data from 44 patients treated by medical healthcare before death. Twenty-five cases had been treated with chronic HD and 19 cases died from ALS. Since air in the bloodline activates coagulation, ME could appear. To discriminate between microbubbles caused by artificial contamination during autopsy versus microbubbles deposited , tissues were stained with a polyclonal fluorescent antibody against fibrinogen, fibrin and fragments E and D. Fluorescence staining was used to visualize ME counted within 25 microscopic fields (600×) of a tissue preparation. One tissue preparation was used if available from the lung, heart and frontal lobe of the brain and in five cases also the cerebellum.
Microbubbles can be verified at autopsy as ME in the lung, heart and brain in tissue from patients exposed to more extensive medical care. There were significantly more ME in the lungs versus the heart or brain. Women had fewer ME than men. The HD group had a higher median of ME per section than the ALS group (lung: 6 versus 3, = .007; heart: 2.5 versus 1, = .013; brain: 7.5 versus 2, = .001) and had more sections with ME findings than the ALS group ( = .002). A correlation existed between the time on HD (months) and ME in the lungs.
More ME were present in HD patients compared with those who suffered from ALS. Minimizing air contamination from syringes, infusions and bloodlines will decrease ME and subsequent tissue injury.
在医疗过程中注入的大量意外空气最终可能会形成栓子，而空气微泡通常会被吸收且不会造成伤害。本尸检研究的目的是调查意外进入血管的空气微泡是否能在肺、脑和心脏等组织中被检测为微栓子（ME）。如果可以，血液透析（HD）患者和肌萎缩侧索硬化症（ALS）患者在微栓子发生率上是否存在差异。
纳入了44例生前接受医疗护理的患者的数据。其中25例接受过慢性血液透析治疗，19例死于肌萎缩侧索硬化症。由于血管内的空气会激活凝血，可能会出现微栓子。为了区分尸检过程中人为污染产生的微泡与沉积的微泡，组织用抗纤维蛋白原、纤维蛋白以及E和D片段的多克隆荧光抗体进行染色。荧光染色用于在组织切片的25个显微镜视野（600×）内观察并计数微栓子。若有来自肺、心脏和脑额叶的组织切片则使用，5例患者还使用了小脑的组织切片。
在接受更广泛医疗护理的患者组织中，尸检时可验证微泡为肺、心脏和脑中的微栓子。肺中的微栓子明显多于心脏或脑。女性的微栓子比男性少。血液透析组每切片的微栓子中位数高于肌萎缩侧索硬化症组（肺：6比3，P = 0.007；心脏：2.5比1，P = 0.013；脑：7.5比2，P = 0.001），且有微栓子发现的切片比肌萎缩侧索硬化症组多（P = 0.002）。血液透析时间（月）与肺中的微栓子之间存在相关性。
与肌萎缩侧索硬化症患者相比，血液透析患者中存在更多微栓子。尽量减少注射器、输液和血管中的空气污染将减少微栓子及随后的组织损伤。
