A 67 year-old woman visited our ER due to remittent fever
and progressive dyspnea for three days.
<Brief
History>
The patient was in good health and exercise capacity.
She started to have cough with mild whitish sputum, headache
with low back pain and poor appetite since the night of
October 11, 2001; she didn't pay much attention to it.
Fever with chills developed on October 12. Common cold was impressed
initially by LMD. On account that spiking fever (up to
40°C) developed on October 15, she visited a community
hospital where leukocytosis was noted, but no definite infectious
focus was told. She was treated with oral medication.
The fever persisted with progressive dyspnea; she was taken to ER
in a university hospital on October 15. The work-up at
ER included: ECG showed normal sinus rhythm and chest
radiograph disclosed a patchy lesion (Figure
1
). Empirical antibiotic
(Ampicillin with sulbactam) was given under the impression
of community-acquired pneumonia. She was admitted to general
ward for further care. Tracing back the history, she lived
in downtown and denied history of travelling to other country
in recent one year. No pet raising or drug history
including herbs were noted preceding this event. On examination,
the blood pressure was 160/90 mmHg and regular pulse rate
100 beats per minute. The body temperature was 40℃ and
respiratory rate 26 per minute. The conjunctiva was not pale and
the sclera was anicteric. There was no neck lymphadenopathy or
goiter palpable. The jugular vein was flat. Chest auscultation
showed coarse crackles over bilateral lower lung fields and
bronchial sound over right lower lung. The heart sound was
regular without murmur. The abdomen was soft and bowel sound
was normoactive. Bilateral lower limb edema was found. No skin
rash nor eschar was found over body surface area.
<Laboratory Data>
1. CBC/DC
|
WBC (K/μL)
|
RBC (M/μL)
|
HB (g/dL)
|
MCV (fL) |
PLT (K/μL)
|
Seg (%) |
Lym (%) |
Eos (%)
|
10/15 |
10.96 |
3.46 |
11.1 |
93.4 |
216 |
90 |
3.5 |
0.1 |
10/19 |
14.55 |
4.04 |
12.3 |
88.6 |
235 |
89.4 |
4.7 |
1.6 |
2. ABG
|
pH |
PaCO2 (mmHg) |
PaO2 (mmHg) |
HCO3- (mEq/L) |
B.E (mEq/L) |
FiO2 |
Ventilator Mode |
10/15 |
7.42 |
31.5 |
77.0 |
19.8 |
-3.7 |
0.3 |
nasal cannula 5 L/min |
10/19 |
7.38 |
45.5 |
62 |
21 |
-2.5 |
1.0 |
Mechanical
ventilation |
3. BCS
|
BUN (mg/dL) |
Cre (mg/dL) |
Na (mmole/L) |
K (mmole/L) |
AST (U/L) |
ALT (U/L) |
CRP (mg/dL) |
10/15 |
19.1 |
0.56 |
135.8 |
3.68 |
26 |
30 |
|
10/19 |
|
|
137.0 |
4.0 |
58 |
24 |
>12 |
4. Coagulation profile
|
PT |
PTT |
10/19 |
14.7/12.4 |
42.6/37.1 |
5. Serologic examination
|
Legionella urinary Ag |
Chlamydia pneumoniae Ag |
Mycoplasma pneumoniae IgM |
10/17 |
positive |
|
|
10/21 |
|
negative |
negative |
<Clincial course & treatment>
Fever persisted under ampicillin with sulbactam.
Hypoxemia progressed, and the O2 demand
increased gradually. Desaturation with drowsy consciousness
was noted on October 17; she was intubated and transferred to
ICU. Atypical pneumonia was suspected, because sputum smear
showed much PMN without bacteria. Antibiotic was shift to
Ciprofloxacin for coverage of legionella infection. Chest
computed tomography (Figure 2
) showed dense pneumonic patch. Refractory hypoxemia
ensured on October 19 under mechanical ventilation with FiO2 1.0
(PaO2/FiO2 <200). Chest
radiograph deteriorated to bilateral diffuse infiltrates.
Swan-Ganz catheter was inserted and the results disclosed good
LV function. Prone position was tried with improvement of
oxygenation . Under the
impression of acute respiratory distress syndrome and well
control of infection, methylprednosolone 160 mg/day was given
since October 24. The oxygenation improved and FiO2 can be
tapered gradually. Extubation was performed on October 28. She
was transferred to general ward and discharged on November 9,
2001 without any sequelae.
案例分析
本案例是一位社區性肺炎的病人,而後惡化為急性呼吸窘迫症候群,其疾病過程可分成以下幾個部份:
1.
有關社區性肺炎的部份:我們必須區分是典型或非典型,本案例比較像是非典型,因(1)病人痰液檢查可見到許多發炎細胞,但是卻看不到有細菌,(2)病人的白血球是相對的偏低,(3)病人的心跳在發燒的情況下是相對的偏低,(4)病人胸部X光片是多個肺葉的肺炎,(5)病人痰液外觀上呈現白稠,而不是傳統的黃濃稠。
2.
病人治療中一度有低血氧的情況,這時候不管是如何調整呼吸器,都沒有辦法提高血氧含量,此時我們必須考慮到是否有一些情況發生: (1)急性肺栓塞:因為是急性發生,會造成右心衰竭,血壓下降,心臟超音波可見右心室脹大,收縮不良,此病人並沒有這些表現。 (2)心因性肺水腫:病人可能因敗血症,而引起左心室衰竭,使氧氣交換惡化,此病人經放置順流導管(Swan-Ganz
catheter),排除此原因。 (3)極嚴重的肺炎:這位病人是屬於這一項原因,以X光片及CT片來看,右肺有非常密緻的肺實質變化。
3.病人肺部情況進入急性肺損傷/急性呼吸窘迫症候群(Acute lung
injury/Acute respiratory distress
syndrome)的階段後,我們採用了一些治療的策略: (1)呼吸器的設定調整為低潮氣容積及高吐氣末正壓呼吸(Low
tidal volume and high PEEP)以避免呼吸器引起的肺損傷。 (2)使用俯臥姿式(Prone
position),目的是為改善肺部通氣與灌流的均衡,以提升氧含量。
(3)使用類固醇,為了改善肺部發炎的狀況,可以縮短病人使用呼吸器的時間,及加護病房的住院天數。
4.
急性呼吸窘迫症候群病人,其預後主要不在於肺部本身嚴重度,而在於整個疾病過程病人器官衰竭之情形,即使經過妥善的照顧,病人仍然有40~60
%死亡率。 |