1. 脂肪塞栓症
Fat Embolism Syndrome (FES)

2. Fat Embolism Syndrome
Am J Med Sci 2008;336:472-7
骨折, 入院の必要な外傷患者の0.3-1.3%でFESが合併.
通常受傷後72hr以内に発症することが多く,
進行性の呼吸不全, 意識障害, 点状出血斑を特徴とする.
死亡率も高く, 7-29%に及ぶ
多発外傷, 骨折での発症が多いが,
DM, 熱傷, 感染症, 悪性腫瘍, Sickle cell anemia,
股関節,膝関節人工骨頭置換術後での発症報告もあり.
(Journal of Thoracic Imaging 2002;17:167-9)

3. Statistical Analysis and Methodological Considerations (Table 2). The incidence of fat embolism syndrome in
Relative risk and 95% confidence intervals (CI) were calculated Am J Med Sci 2008;336:472-7
patients with joint replacement of the lower extrem-
using calculator for confidence intervals of relative risk (www. ity, arthroplasty and repair of shoulder or elbow,
sign.ac.uk/methodology/risk.xls). bone graft, limb shortening, limb lengthening, os-
1979-2005年の米国の入院患者の0.004%がFES
Results
teotomy, and spinal fusion were too low to calculate
accurately.
From 1979 through 2005 among 928,324,000 pa- Nonorthopedic conditions including decompres-
tients discharged from short-stay hospitals, 41,000 sion sickness, third degree burns, bone marrow
transplantation, crushing injury (excluding frac-
大 骨, 頸骨, 腓骨, 骨盤, 肋骨, 上腕骨, 橈骨, 尺骨
(0.004%) had fat embolism syndrome. The incidence
of fat embolism remained relatively unchanged over ture), pancreatitis, diabetes mellitus, panniculitis,
the interval of study (Table 1). Among 23,829,000 fatty liver, and sickle cell anemia were either not
上記いづれかの単独骨折患者の0.12%でFESを合併.
patients with isolated or multiple fractures involv- accompanied by fat embolism syndrome or only
rarely, and the incidences were too low to calculate
ing the femur (any site), tibia, fibula, pelvis, ribs,
accurately.
多発骨折を含むと0.17%でFESを合併.
humerus, radius, or ulna, 41,000 (0.17%) developed
fat embolism syndrome. The fracture site most fre- The fat embolism syndrome was more frequent in
quently responsible for fat embolism was the femur men (relative risk 5.71) (Table 3). A higher propor-
(Figure 1). The incidence of fat embolism was higher tion of men had fractures of the femur (excluding
in patients with multiple fractures of these sites neck), tibia or fibula than women (25% versus 14%),
FES患者の骨折の種類, 頻度;
[16,000 of 2,291,000 (0.70%)] than in patients with and fewer men had isolated fractures of the neck of
the femur (24%) than women (45%). Fractures of the
isolated fractures of these sites [25,000 of 21,538,000
(0.12%) (P Ͻ 0.0001)]. pelvis, ribs, humerus radius, or ulna occurred in
Among 388,000 patients with multiple fractures 51% of men and 41% of women.
大 骨骨幹部骨折が最多.次いで頸骨, 腓骨.
that included the femur (excluding neck), 1.29% had
fat embolism syndrome (Table 2). Among 1,643,000
Among 1,178,000 patients aged 0 to 9 years who
had isolated fractures of the femur (any site), tibia,
40
頚部骨折は頻度は低いが,
34
全体では17%を占める
Fat Embolism Syn (%)
30
25 24
Figure 1. Percentage of hospitalized patients with 20
the fat embolism syndrome (syn) who had isolated
or multiple fractures of the femur (other than 17
neck), tibia or fibula, neck of the femur, or pelvis,
humerus, ribs, or ulna. 10
0
Femur Other than Tibia or Fibula Femur Neck Pelvis/Humerus/
Neck Ribs/Radius or
Ulna
Isolated or Multiple Fractures
THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES 473

4. Am J Med Sci 2008;336:472-7
多発骨折ほどRiskは高い(0.70% vs 0.12%)
多発or単独 多発 単独 RR
大 骨骨幹部 0.68% 1.29% 0.54% 2.35[2.27-2.43]
大 骨頸部 0.09% 稀 0.06% 稀
頸骨, 腓骨 0.40% 稀 0.30% 稀
骨盤, 肋骨, 上腕, 橈骨, 尺骨 0.09% 稀 稀 稀
Internal fixation 0.15% 稀 稀 稀
また, 男性の方がFES発症riskが高い(RR5.71)
10-39yrでの発症率が0.37%と高く,
若年者では少ない. >40yrでは0.05%とやはり若干少なくなる.

5. FESの症状
血中に混入した脂肪組織は主に肺でTrapされる.
他には脳, 腎, 心筋, 他臓器でTrapされ, 症状を来す.
肺でTrapされた脂肪は先ず閉塞による症状を来す.
>> 右室負荷, 肺高血圧, 低酸素, 閉塞性Shock.
その後, 肺でLipaseが分泌され,
脂質はFree fatty acidとGlycerolに分解される.
>> Free fatty acidにより肺血管透過性が亢進.
肺胞構造, サーファクタントを障害する.
上記機械的閉塞, 化学的損傷の2つの機序で低酸素を来す.
化学的損傷はDelayがあり, 骨折後24-72hrで起こる.
これに対するステロイドは効果的かもしれない.
Clinical Orthopaedics and Related Research 2004;232:263-70

6. FESの診断
臨床診断
外傷後の多呼吸, 呼吸苦, 気管分泌液増加.
意識の変容, 点状出血の出現はFESを強く示唆する所見.
血液検査; 明らかに有用なのはPLTのみ.
PLT低下(<150k)はFES診断に重要な所見となる.
Lipuriaは骨折患者の1/2で認められる.
高感度であり,臨床的に使用できるかははっきりしない.
喀痰中の脂質, リパーゼも骨折患者では多く認められるため,
臨床的にはあまり役に立たない.
血液中のFat dropletsも高感度であり, 特異性は低い.
Clinical Orthopaedics and Related Research 2004;232:263-70

7. 診断Criteria (1970)
Criteriaは古く, 感度, 特異度ともに不明確. 参考程度に.
≥1 major, ≥4 minorで診断 J Bone Joint Surg Br 1970;52:732–37.
J Bone Joint Surg Br 1974;56:408-16
Major Minor
頻脈
発熱≥38.5
PaO2<60mmHg 網膜塞栓
肺水腫 Lipuria
低酸素と関係がない意識障害 説明困難なHtの低下
腋窩, 結膜の点状出血 PLT低下
ESR上昇
喀痰中の脂肪滴

8. 100名のFES患者の解析
臨床症状
呼吸器症状は75名で認められ,呼吸苦,多呼吸,湿性ラ音が主.
PaO2<50が24/50名, 50-80が17/50名.
胸部XPは52名で評価され, 43/52で両側性びまん性浸潤影.
9/52で正常所見であった.
中枢症状を呈したのは80名. 様々なレベルの意識障害を来す. 50 per cent or more was found
THE FAT EMBOLISM
in twenty-three, with
SYNDROME
minimum values of un
millimetre in twelve patients. In eighty-seven cases the erythrocyte sedimenta
raised, with values of 30 to 50 millimetres in sixteen cases, 51 to 70 millimetres
cases, and over 71 millimetres in fifty-four cases. Fat globules larger than
点状出血斑は57名.初期では腋窩の前方,頚部で多く認められる. found circulating
the clinical severity
in all cases. The amount
of the condition.
of circulating fat did not appear
頬粘膜,結膜でも認めやすい.
眼底所見は54/63で正常.
.‘.
C
The Journal of Bone and Joint Surgery 1974;56:408-16
FIG. 2

9. FESの肺所見
5名のFES患者では,
胸部XP所見; 正常所見が2名. 両側透過性低下が3名.
分布はDiffuseが2名で, 中下肺優位が1名
CT所見;浸潤影が3名. GGOは全例(5名).
結節影は4名で認められた.
分布は様々. 上肺野1名, Dependent zone 2名, 下肺2名.
両側の胸水は3名で認めた.
XPで異常を認めた3名は15d[4-15]で正常化
CTのみで異常を認めた2名はそれぞれ1,4moで正常化.
J Comput Assist Tomogr 2006;30:254-7

10. puted tomography scans of the 4 patients diagnosed with FES and with a nodular pattern at CT exami
4名のNudular Patternを示したCT
nodules were small, with ill-defined margins and a centrilobular and subpleural distribution. A, Patient
J Comput Assist Tomogr 2006;30:254-7
pattern (arrowheads) and alveolar opacities in the lower lobes. B, Patient 3 has subpleural nodules (arro

11. FES6名のCT所見
平均年齢21.8yr[19-25], 四肢の骨折に伴うFES.
点状出血は2/6, 脳MRIで異常を認めたのは2/5.
低酸素は平均14.3d[5-30]で改善.
CT所見
CT所見
Multiple patchy 5/6 上肺優位 5/6
Diffuse alveolar opacities 1/6 末梢,中枢優位 偏在無し
Small nodular opacities 2/6 正常化までの期間 7d[2-11]
胸水 1/6
結節は2-10mmで, 肺動脈末梢に認めることが多い.
重力に依存した領域(下肺背側)の異常所見は全例認められた.
Journal of Computer Assisted Tomography 2000;24:24-29

12. Figure 1. Continued Figure 1. Continued
Ovid: Pulmonary Fat Embolism Syndrome: CT Findings in Six Patients.
Figure 1. Continued Figure 1. Continued
On CT scans, multifocal areas of consolidation and ground-glass opacity were seen in all patients. These areas
of consolidation and ground-glass opacity ranged from 10 to 40 mm (Fig. 1). In another patient, diffuse
consolidation was noted as well as multifocal areas of consolidation and ground-glass opacity, which involved all
lobes (Fig. 2). Nodules were seen in all patients. The nodules ranged from 2 to 10 mm and were well defined in
three patients and ill defined in three. The nodules were closely associated with the peripheral branch pulmonary
Figure 2. Continued
artery in three patients (Fig. 1). All three of these characteristics were seen predominantly in the upper lobes in
Journal of Computer Assisted Tomography 2000;24:24-29
five patients. In the remaining patient, the abnormal opacities involved all lobes evenly. In four patients, these

13. FESの治療
基本的には対症療法
早期発見, 血ガスフォロー, 酸素投与が基本.
Shockがあれば大量補液.
骨折の早期内固定も重要.
化学的肺損傷を予防する目的での
ステロイド大量投与は有効かもしれない.
Clinical Orthopaedics and Related Research 2004;232:263-70