A 65-year-old man was admitted due to intermittent
fever for 3 months and progressive shortness of breath for
half a month.
Brief
History
The patient had been well until Dec.
2001, when he suffered from intermittent high fever after
visiting a dental clinic for periodontitis. The fever
initially subsided after taking some drugs from a clinic but
recurred several days later. In January 2002, he started to
have generalized myalgia & both hands arthralgia.
Abdominal pain over LUQ developed in the early Feb. 2002; he
visited a community hospital where spleen infarction was
suspected after a CT scan. Splenectomy was performed on Feb.
17, of which pathology revealed massive hemorrhage with
suppurative inflammation and neutrophil infiltration. One week
after operation, fever recurred and associated with dyspnea,
generalized arthralgia, anorexia, night sweats, and
significant weight loss (6 kg/3 months). Due to deterioration
of dyspnea, he visited an ER of a university hospital where a
CXR showed cardiomegaly with lung congestion (Figure
1
). He was admitted under the impression of congestive
heart failure on March 5, 2002.
The patient denied drug abuse or prostitute exposure. He
was a heavy smoker before but quitted for one year. His
occupation is a taxi driver. He had been to Mainland China
eight years ago and no other travel history since that
time.
On physical examination, the patient appeared tired but not
acutely ill. His consciousness was clear and oriented. The
blood pressure was 130/90 mmHg. The temperature was 37.4 ℃,
the pulse rate was 105 /min, and the respiration rate was
25/min. The head was normal, and the conjunctivae were mild
pale. The sclerae were not icteric. The neck was supple
without lymphadenopathy. The jugular vein was engorged. The
breath sounds were bilateral basal crackles. The heart beats
were regular with a Gr.II/VI systolic murmur over left upper
sternal border and S3 gallop. The abdomen was soft and flat;
no tenderness or rebound tenderness was noted. The liver was
not palpable. The extremities moved freely without edema or
petechiae.
Laboratory
Data
1. CBC/DC
|
WBC(K/μL) |
RBC(M/μL) |
HB(g/dL) |
MCV(fL) |
PLT(K/μL) |
Seg(%) |
Lym(%) |
Eos(%) |
3/5 |
14.17 |
2.95 |
9.3 |
100.3 |
114 |
84.6 |
10.7 |
4.2 |
3/7 |
49.91 |
3.27 |
10.2 |
101.5 |
125 |
94.1 |
2.5 |
0.2 | 2.
ABG
|
pH |
PaCO2(mmHg) |
PaO2(mmHg) |
HCO3-(mEq/L) |
B.E(mEq/L) |
FiO2 |
Ventilator Mode |
3/5 |
7.531 |
19.6 |
144.5 |
16.5 |
-3.4 |
0.4 |
O2
cannula | 3. BCS
|
T-Bil(mg/dL) |
D-Bil(mg/dL) |
AST(U/L) |
ALT(U/L) |
BUN(mg/dL) |
Cre(mg/dL) |
CK(U/L) |
3/5 |
1.71 |
0.5 |
58.0 |
22.0 |
50.0 |
0.85 |
|
3/7 |
2.84 |
1.82 |
3546 |
1589 |
63.1 |
3.61 |
1504.0 |
|
Na(mmole/L) |
K(mmole/L) |
Cl(mmole/L) |
CRP(mg/dL) |
LDH(U/L) |
Lactic acid(mmole/L) |
3/5 |
141.0 |
4.5 |
103.0 |
2.3 |
|
|
3/7 |
142.0 |
5.39 |
101.1 |
>12 |
2560 |
>12 | 4. Coagulation profile
|
PT |
PTT |
3/7 |
24.6/12.4 |
65.4/37.1 | 5.
Urinalysis
|
Sp. Gr |
pH |
protein |
Glu |
Keton |
Urobil |
O.B. |
RBC |
WBC |
Cast |
3/5 |
1.005 |
5.0 |
30 |
- |
- |
- |
3+ |
20-25 |
0-2 |
Hy-Gr (3-5) |
Clincial course
& treatment
After admission, progressive dyspnea
with impending respiratory failure was noted. He was intubated
and transferred to ICU on March 7. Hypotension was noted and
dopamine & dobutamine were administered. Intravenous
furosemide was given for oligouria. Empirical antibiotic of
ceftriaxone, penicillin-G and minocycline were given. Two days
later, Janeway lesions were noted at acral part of four
extremities. Transesophageal echocardiography showed
vegetations on aortic valve (Figure
2 ) and severe aortic
regurigatation. Subacute Infective endocarditis was diagnosed.
Blood cultures yielded Streptococcus mitis in three sets and
antibiotics were shifted to ceftriaxone and penicillin-G. He
started to wean from ventilator and extubation was performed
on March 9, 2002. Slurred speech was noted and embolic stroke
was suspected. Brain MRI showed multiple small acute infarcts.
Cardiovascular surgeon was consulted and operation was not
suggested. Paroxysmal atrial fibrillation occurred in the noon
on March 10 and intravenous amiodarone was given. Severe
dyspnea with consciousness change was noted in the afternoon
of March 10. Blood gas showed severe metabolic acidosis.
Refractory hypotension occurred. Emergent operation was
performed in the morning of March 11. Operation findings
showed severe destruction of aortic valve (Figure
3) with perforation (Figure
4
). After operation, he was transferred to
surgical ICU for further management.
案例分析
本案例是一位細菌性心內膜炎的病人,病程進行到最後心臟衰竭及敗血性休克。整個病程可為三個階段:第一階段為明顯感染徵候期,病人此時有持續性發燒不退,白血球偏高,雖經藥物治療只能得到暫時緩解;病人此時發生了脾臟梗塞的現象,這是一個很重要需要鑑別診斷的問題,一般來說原因有三種:(1)
血液學疾病,如淋巴瘤、白血病及鐮刀型貧血;(2) 血栓栓塞問題,如敗血性栓塞、動脈阻塞;(3)
肉芽瘤(granuloma)或不明原因。病人經脾臟切除後,其病理切片結果顯示為化膿性變化,且有明顯白血球浸潤現象,這些都暗示著有細菌性的感染在進行,在這個階段應當詳細追查身體可能的感染源,予以徹底治療。第二階段為全身性發炎反應及心臟瓣膜嚴重破壞後所產生的心臟功能失衡現象,病人有貧血、全身關結酸痛、肌肉酸痛、心臟功能衰退而產生運動耐受性不良及呼吸急促現象,整個過程可以緩慢進行達數個月之久,甚至被當作不明熱(Fever
of unknown
origin)治療,這個階段如果可以仔細訊問病史,小心進行理學檢查,可以發現引起心內膜炎的原因(如本案例病人有接受牙科治療),及心臟有心雜音的表現。第三階段,病程已經進入嚴重期,所有各器官系統都因為細菌性血栓瀰漫散布,而引起多重器官衰竭,如本案例之心臟衰竭、腎臟衰竭、及腦栓塞等。病人此時接受外科手術,也是在不得已的情形下進行。
感染性心內膜炎,主要診斷依據Modified Duke
criteria,分成(1)主要診斷:有血液培養兩套出病原菌,及新發生瓣膜閉鎖不全或心臟超音波可見病兆。(2)次要診斷:有引起此疾病之危險因子、發燒、血栓栓塞在全身之變化,免疫反應,及其它微生物學發現等(Reference:NEJM
2001; 345:1318-1330)。感染性心內膜炎一般培養出來的病原菌,可能是Streptococcus sp.
Staphylococcus aureus ,Gram-negative
bacilli,或者Fungi,可以隨著是native-valve,或prosthetic-valve及不同年齡,術後發生時間而有不同比例的分佈。
感染性心內膜炎的治療,包含內科抗生素及外科手術,抗生素治療以培養出來結果所作之藥物敏感性試驗為依據,對於有作血液培養卻沒有長出微生物者,就必須依據病人危險因子及臨床表現,給予經驗性用藥,可能要包含penicillin,
ampicillin,
ceftriaxone或vancomycin通常要合併使用aminoglycoside。手術的時機有(1)心臟衰竭;(2)瓣膜周圍有侵犯;(3)臨床感染無法用抗生素控制下來;或者(4)特別病原菌如Pseudomonas
aeruginosa, Brucella sp. Coxiella burnetii, candide
sp.等。若病人近期有心內膜炎引起之神經學症狀,一般建議要延遲手術2∼3週,經抗生素充分治療後才進行手術。
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