Nontraumatic Multiple-Organ Fat Embolism

Abstract

The patient was an 88-year-old woman with a 10-year history of hypertension. She was suspected to have been hit by a car. At the time of the event, she was conscious and able to stand on her own and had no obvious injuries. She was sent home, but she lapsed into unconsciousness and was nonresponsive after 2 hours. She was sent to the hospital, and her heartbeat and breathing stopped. After half an hour of rescue attempts, her heartbeat did not recover, and she was declared dead. During the autopsy, a small subcutaneous hemorrhage was observed below the right knee joint. No obvious internal organ injuries or bone fractures were observed. The deceased also had mild atherosclerosis in the coronary arteries and an old cerebral infarction in the right cerebellum. The tissue histopathological tests showed distinct fat embolism in multiple organs, including the brain, lungs, kidneys, liver, and pancreas. A postmortem blood biochemistry test of the heart blood showed that the levels of low-density lipoprotein, cholesterol, triglycerides, and free fatty acids in the blood were increased, and the level of C-reactive protein was elevated. According to the autopsy results, the direct cause of death was multiorgan fat embolism. This case suggests that aging, hypertension, and hyperlipidemia may be risk factors for nontraumatic fat embolism under stressful conditions.

Rare, Fatal Pulmonary Fat Embolism after Acupuncture Therapy: A Case Report and Literature Review

“…Signi cantly minor adipose tissue injury in the presence of trauma is an indication of death from nontraumatic pulmonary fat embolism. Examinations of sites for fat emboli should include each major organ [3] as well as the peripheral arterial system and the venous system draining from noninjured sites to identify the possible source of the fat embolus. It has been reported that biochemical testing of the deceased's cardiac blood should be performed, with attention to abnormal changes in VLDL, cholesterol, TG, FFA, and CRP [3].…”

“…Examinations of sites for fat emboli should include each major organ [3] as well as the peripheral arterial system and the venous system draining from noninjured sites to identify the possible source of the fat embolus. It has been reported that biochemical testing of the deceased's cardiac blood should be performed, with attention to abnormal changes in VLDL, cholesterol, TG, FFA, and CRP [3]. Lipid analysis of fat emboli, if necessary, may also be performed, which may suggest a possible mechanism of pulmonary fat embolism formation [4].…”

“…It is most frequently observed following severe trauma, particularly long bone fractures and contusions in soft tissue rich in adipose tissue. Nontraumatic pulmonary fat embolism associated with minor soft tissue contusion [2,3], surgery, cancer chemotherapy, hematologic disorders and so on has also been reported [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Intrinsic or extrinsic stimuli evokes a biological response, known as stress [19]; stress can be induced by trauma, blood loss, hypoxia, pain, heat and cold, fear, infection, surgery, and anesthesia.…”

“…It should be noted that pulmonary fat embolism caused by stress is sometimes associated with mild tissue damage, but some stress-related factors, such as strong external stimuli and mental stimulation, are essential. Additionally, subclinical conditions, such as obesity, multiple organ adipose hyperplasia and other conditions, may be risk factors for nontraumatic fat embolism [3].…”

“…PubMed was searched with different combinations of the following keywords: "fat embolism", "nontraumatic", "death", "autopsy", and "case report". Table 1 lists 18 case reports [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] (including this case report) of nontraumatic fat embolism caused by stress, summarized by year, PMID, author age, sex, underlying disease, stress factors, early clinical manifestations, diagnosis tool, affected organs and deterioration. None of these cases had severe fatty tissue damage or long bone fractures, and those with surgical trauma had only minor adipose tissue damage.…”