Pneumoperitoneum Caused by Ruptured Gas-Containing Pyogenic ...

Pneumoperitoneum, pyogenic liver abscess
11
Pneumoperitoneum Caused by Ruptured Gas-Containing
Pyogenic Liver Abscess: A Case Report and Literature Review
Chih-Chung Chao 1 , Sung-Yuan Hu 2,3,4,5 , Ying-Hock Teng 1,3
Pneumoperitoneum reflects intra-abdominal visceral perforation in 85 to 95 % of all occurrences.
In 5 to 15 % of cases, however, pneumoperitoneum does not reflect perforation and results from another
source. Herein, we report a rare case of surgery indicated pneumoperitoneum caused by the rupture
of gas-containing pyogenic liver abscess (GPLA) in a newly-diagnostic diabetic 57-year-old man. He
presented the symptoms mimicking intra-abdominal visceral perforation. He recovered uneventfully after
surgical intervention, drainage, full-course of antibiotics and strict control of blood glucose. Cultures of
blood and ascites grew Klebsiella pneumoniae.
Key words: gas-containing pyogenic liver abscess (GPLA), pneumoperitoneum, rupture
Introduction
Acute abdomen is a common and emergent
condition in the emergency department (ED).
Indeed, it is necessary to be investigated
immediately and treated it without delay.
Pneumoperitoneum is the term used to describe
the presence of free air within peritoneal cavity
but outside the viscera. In the major cases of
pneumoperitoneum, it is the result of intraabdominal
visceral perforation, especially the
hollow organs (1) . Gastric and duodenal ulcers
account for the majority of these cases (2) . Generally,
prompt surgical intervention is required in these
patients. Ruptured GPLA is a rare cause of surgery
indicated pneumoperitoneum (3-6) .
Case Report
A 57 year-old man presented to the ED with
fever, productive cough and general weakness for
1 week. He denied any systemic disease in the
past except herbal drugs for polydipsia, polyuria,
polyphagia and body weight lost from 78 to 50 kg
in recent 3 years. On arrival of ED, vital signs
were body temperature of 36.1℃, blood pressure
164/106 of mmHg, heart rate of 96 beats/min
and respiratory rate of 18 breaths/min. Physical
examination revealed coarse crackles over the
right lung field, soft abdomen on palpation, normal
peristalsis on auscultation and there were no
localized tenderness, rebounding pain or percussion
pain over the right flank and right lower chest
regions. First look of the upright chest X-ray
(CXR) (Fig. 1) was increased infiltration over right
lung field. Laboratory investigations were white
blood cell counts 33960/μL with 90% neutrophils
and 2.5% bands, C-reaction protein 31.6 mg/dL,
glucose 838 mg/dL, HbA1c 14.6%, aspartate
aminotransferase 117 U/L, alanine aminotransferase
Received: August 22, 2011 Accepted for publication: December 17, 2011
From the 1 Department of Emergency Medicine, Chung Shan Medical University Hospital; 2 Division of Toxicology, Department
of Emergency Medicine, Taichung Veterans General Hospital; 3 School of Medicine, Chung Shan Medical University; 4 Institute
of Medicine, Chung Shan Medical University; 5 National Taichung Nursing College, Taiwan (R.O.C.)
Address reprint requests and correspondence: Dr. Sung-Yuan Hu
Division of Toxicology, Department of Emergency Medicine, Taichung Veterans General Hospital
160 Section 3, Chung-Kang Road, Taichung, Taiwan (R.O.C.)
Tel: (04)23592525 ext 3670 Fax: (04)23594065
E-mail: song9168@pie.com.tw

12
J Emerg Crit Care Med. Vol. 23, No. 1, 2012
Fig. 1
The upright chest X-ray showed small air bubbles (black
arrow) superimposing at upper liver area, which were
suggestive of a gas-containing pyogenic liver abscess (GPLA)
90 U/L, total bilirubin 0.8 mg/dL, alkaline
phosphatase 123 U/L. Then he was admitted
under the impression of newly-diagnostic diabetes
mellitus (DM), pneumonia and impairment of liver
function test, nature to be determinated.
Abdominal sonography was scheduled on next
day. However, sudden onset of abdominal pain
over right upper quadrant (RUQ) with vomiting
occurred on the second day. Physical examination
revealed diffuse tenderness, especially over RUQ,
with muscle rigidity and rebounding pain, but
the absence of Murphy’s sign. First look of the
second upright CXR (Fig. 2) showed bilateral
subphrenic free air and right side pleural effusion.
Second look of the first (Fig. 1) and the second
(Fig. 2) upright CXR revealed small air bubbles
superimposed at upper liver area was suggestive
of GPLA. Abdominal computed tomography (CT)
scan (Fig. 3) disclosed a big GPLA in right lobe of
liver, 11.6 x 10 x 6.8 cm in size, intra-abdominal
free air, ascites and right side pleural effusion. An
emergency surgical intervention was conducted
under the tentative diagnosis of secondary
peritonitis due to ruptured GPLA.
After surgical intervention, peritoneal lavage,
drainage, antibiotic treatment and strict control of
blood glucose, the infection was well controlled and
he was discharged smoothly on the postoperative
14th day. Cultures of blood and ascites yielded
Klebsiella pneumoniae.
Discussion
Pneumoperitoneum usually can be detected
by upright chest and left lateral decubitus of
abdomen radiographs, but CT scan is more sensitive
to detect than upright CXR (7) . In 5 to 15% of
cases, pneumoperitoneum does not reflect intra-

Pneumoperitoneum, pyogenic liver abscess
13
Fig. 2
The upright chest X-ray showed right side pleural effusion,
bilateral subphrenic free air (white arrows), and small air bubbles
(black arrow) superimposing at upper liver area, which were
suggestive of a GPLA with free air in the peritoneum
Fig. 3
A contrast-enhanced abdominal computed tomographic scan
showed a GPLA in right lobe of liver, 11.6 x 10 x 6.8 cm in size
(black arrow), intra-abdominal free air (white arrow) and ascites

14
J Emerg Crit Care Med. Vol. 23, No. 1, 2012
abdominal visceral perforation and results from
another source and such a situation is termed
spontaneous pneumoperitoneum (SP) or nonsurgical
pneumoperitoneum (NSP) (1,8) . SP and NSP can be
classified according to the source as 5 categories
as below (Table 1): (1) Thoracic; (2) Abdominal;
(3) Gynecologic; (4) Miscellaneous and idiopathic;
(5) Pseudopneumoperitoneum (1-2,4-9) . Most cases of
NSP occurred as a procedural complication or as
a complication of medical intervention. The most
common sources of NSP are from thoracic route (3,9) .
When abdominal pain and distension are minimal
and peritoneal signs, fever, and leukocytosis are
absent, NSP should be considered.
P y o g e n i c l i v e r a b s c e s s ( P L A ) i s n o t
uncommon and sometimes life-threatening. PLA
is associated with high mortality as the diagnosis
is often delayed. In recent decades, its recognition
Table 1 Causes of spontaneous and nonsurgical pneumoperitoneum
Category
Causes
Thoracic Mechanical ventilation Cardiopulmonary resuscitation
Mask ventilation
Bronchoscopy
Pneumothorax
Asthma
Atelectasis
Chronic obstructive pulmonary disease
Bullous emphysema
Bronchopulmonary fistula
Pulmonary sepsis, tuberculosis Blunt trauma
Blast injury
Tracheal rupture
Increased intrathoracic pressure such as cough, retching
Barotrauma
Valsava maneuver
Quick decompression while scuba diving
Procedure related such as median sternotomy, heart transplant
Abdominal Open laparotomy Laparoscopic procedure
Peritoneal dialysis
Endoscopic procedures
Blunt, penetrating trauma Colon contrast examination
Splenic embolization
Pneumatosis cystoides intestinalis
Diverticulosis
Spontaneous bacterial peritonitis
Pneumocholecystitis
Gas-containing pyogenic liver abscess
Collagen vascular disease Subclinical perforated viscus
Gastric emphysema
Gas-producing organism infection
Gynecologic Coitus Postpartum knee-chest exercise
Orogenital sex
Vaginal insufflation and douching
Ovarian cancer
Gynecologic examination procedures
Gas-producing organism infection
Miscellaneous and Idiopathic Cocaine use
Aerophagia
Amyloidosis
Dental extraction
Adenotonsillectomy
Tracheostomy
Scleroderma without pneumatosis cystoides intestinalis

Pneumoperitoneum, pyogenic liver abscess
15
has clearly improved through the advance of
more sensitive and specific imaging techniques,
such as ultrasonography and CT scan, with their
relevant therapeutic implications (10) . Improvement
of diagnosis and treatment methods over the
past more than 60 years, so the mortality rate of
PLA has decreased from 79.6% to 1.47-15% and
mortality rate of PLA was 10.9% during 1996-2004
in Taiwan (11,12) . However, only 10% of PLA
patients presented with the classic triad of fever,
jaundice, and RUQ abdominal tenderness (13) . Based
upon the lack of specificity of clinical symptoms
and signs, as well as laboratory parameters, so
promptly diagnosing PLA remains a task for the
for emergency physicians because the time for
evaluation of PLA patients is often limited (14) .
Clues for diagnosis of PLA in the ED can be
classified as 5 categories as below (Table 2): 1.
Presenting symptoms; 2. Physical examination
findings; 3. Predisposing factors; 4. Laboratory
abnormalities; 5. Abnormal findings in chest and
abdomen radiographs (13-15) . Among these clues,
fever and RUQ abdominal pain are the most
typical symptoms; RUQ abdominal tenderness or
jaundice is the most common physical examination
findings (13-15) . The first evaluation of an occult liver
abscess may be improved by a history directed
to identification predisposing conditions, mainly
immunosuppression and hepatobiliary disorders. 14
PLA should be considered when physicians met
patients with typical or several clues of PLA.
The most appropriate treatment for PLA is
antibiotic therapy with percutaneous drainage
under ultrasonic guidance if indicated (11,16) . DM is
the most common underlying disease in patients
with PLA (11,16) . 85.5% of patients with GPLA and
60.9% of patients with ruptured PLA had DM (3,4,17) .
In Taiwan, PLA caused by Klebsiella pneumoniae
has long been recognized, and its incidence was
reported to range from 50% to 88% of the over
all PLA (3,12) . Klebsiella pneumoniae is the most
common pathogen of GPLA, PLA and ruptured
PLA (3,4,12,17-18) . The incidence of rupture in PLA is
about 5.5% (3,4) . The occurrence of gas formation in
PLA is 7%-24% (18) . Although gas-forming bacterial
infections are generally caused by anaerobic
organisms, but majority of all GPLA have been
reported to be caused by aerobic organism such as
Table 2 Clues for diagnosis of pyogenic liver abscess in the emergency department
Category
Presenting symptoms
Physical examination
findings
Predisposing factors
Abnormal findings in chest and
abdomen radiographs
Laboratory abnormalities
Clues
Fever, Abdominal pain, Chills, Nausea, Vomiting, Anorexia, Weight loss,
Malaise, Diarrhea, Chest pain, Cough
Jaundice, RUQ tenderness, Hepatomegaly, Splenomegaly, Ascites, Sepsis
syndrome, Muscle rigidity, Rebounding pain
DM, Hepatobiliary disorders (including liver transplantation), HIV
infection, Concomitant neoplasm, Alcoholism, Recent abdominal
surgery (in previous recent weeks), Chronic brucellosis, Steroidal and
Immunosuppressive therapy
Elevated right hemidiaphragm, Right basilar infiltration, Right pleural
effusion, Air bubbles over liver area, Pneumoperitoneum
Hyperbilirubinemia, Elevation of blood liver enzymes or alkaline
phosphatase, Leukocytosis, Hypoalbuminemia, Anemia

16
J Emerg Crit Care Med. Vol. 23, No. 1, 2012
Table 3 Poor prognostic factors of pyogenic liver abscess
APACHE II score at admission ≥15 Compromised immune status
Malignancy
Diabetes mellitus
Uremia
Senility
Hyperbilirubinemia 1 High level of blood creatinine 2
High level of blood urea nitrogen 3
Hyperglycemia
MDR isolates
Bacteremia
Polymicrobial infection 4 Anaerobic infection 4
Non-K. pneumoniae infection 4
Antibiotics alone
Diagnostic delay
Multiple abscesses
Bi-lobe involvement
Gas-forming liver abscess
Alveolar gas pattern and pneumoperitoneum as viewed on radiographs
Globular configuration, shaggy margin, alveolar internal structure, and total gas content on CT scans.
APACHE = Acute Physiology And Chronic Health Evaluation, MDR = multi-drug resistant, K. pneumoniae
= Klebsiella pneumoniae, 1 = blood total bilirubin > 20.52 μmol/L, 2 = blood creatinine > 115 μmol/L, 3 =
blood urea nitrogen>7.86 mmol/L, 4 = isolated pathogen growing in blood or abscess cultures
Klebsiella pneumonia and Escherichia coli (18) . The
impairment of local perfusion may also inhibit the
removal of gas from the infected tissue and cause
the GPLA (5) . However, if rupture of PLA occurs
and signs of acute peritonitis present, surgery
is the only treatment for this condition (5) . Poor
prognostic factors of PLA are listed at Table 3 (19,20) .
Multivariate analysis revealed that gas-forming
abscess, multi-drug resistant isolates, anaerobic
infection, blood urea nitrogen level >7.86 mmol/l,
and APACHE II score ≥15 were associated with
high mortality (20) .
I n s u m m a r y, i n s o m e o f t h e c a s e s o f
pneumoperitoneum, the physicians didn’t make
a proper diagnosis until surgical intervention.
Pneumoperitoneum with acute abdominal pain is
mostly secondary to hollow organ perforation, but
there are still some other causes which present the
similar clinical condition. Rupture of GPLA is a
rare one of them and can mimic intra-abdominal
visceral perforation. When physicians meet patients
who have pneumoperitoneum with acute abdominal
pain and the clinical clues of PLA exist. It must
be borne in mind that rupture of GPLA is one
of the differential diagnoses. Further abdominal
sonography, even abdominal CT scan is needed to
establish the proper diagnosis for immediate and
definite managements.
References
1. Mularski RA, Sippel JM, Osbrone ML.
Pneumoperitoneum: a review of nonsurgical
causes. Crit Care Med 2000;28:2638-44.
2. Mularski RA, Ciccolo ML, Rappaport WD.
Nonsurgical causes of pneumoperitoneum.
West J Med 1999;170:41-6.
3. Lee CH, Leu HS, Wu TS, Su LH, Liu JW. Risk
factors of spontaneous rupture of liver abscess
caused by Klebsiella pneumoniae. Diagn
Microbiol Infect Dis 2005;52:79-84.
4. Chou FF, Sheen-Chen SM, Lee TY. Rupture
of pyogenic liver abscess. Am J Gastroenterol
1995;90:767-70.
5. Ukikusa M, Inomoto T, Kitai T, et al.
Pneumoperitoneum following the spontaneous

Pneumoperitoneum, pyogenic liver abscess
17
rupture of a gas-containing pyogenic liver
abscess: report of a case. Surg Today
2001;31:76-9.
6. S h u m H C, G a u J S, L i a o T H, e t a l.
S p o ntaneously ruptured gas-containing
pyogenic liver abscess: an unusual case of
pneumoperitoneum. Chin J Radiol 2004;29: 203-6.
7. Stapkis JC, Thickman D. Diagnosis of
pneumoperitoneum: abdominal CT vs.
upright chest film. J Comput Assist Tomogr
1992;16:713-6.
8. Williams NM, Watkin DF. Spontaneous
pneumoperitoneum and other nonsurgical
causes of intraperitoneal free gas. Postgrad
Med J 1997;73:531-7.
9. Chen WT, Lee BC, Tsai MJ. Pneumoperitoneum
without hollow organ perforation: a case report.
J Taiwan Emerg Med 2011;13:48-52.
10. Jiménez E, Tiberio G, Sánchez J, Jiménez FJ,
Jiménez G. Pyogenic hepatic abscesses: 16
years experience in its diagnosis and treatment.
Enferm Infecc Microbiol Clin 1998;16: 307-11.
11. Stain SC, Yellin AE, Donovan AJ, Brien HW.
Pyogenic liver abscess: modern treatment. Arch
Surg 1991;126:991-6.
12. Tsai FC, Huang YT, Chang LY, Wang JT.
Pyogenic liver abscess as endemic disease,
Taiwan. Emerg Infect Dis 2008;14;1592-600.
13. Johannsen EC, Sifri CD, Madoff LC. Pyogenic
liver abscesses. Infect Dis Clin North Am
2000;14:547-63.
14. Hernández JL, Ramos C. Pyogenic hepatic
abscess: clues for diagnosis in the emergency
room. Clin Microbiol Infect 2001;7:567-70.
15. Rahimian J, Wilson T, Oram V, Holzman
RS. Pyogenic liver abscess: recent trends
in etiology and mortality. Clin Infect Dis
2004;39:1654-9.
16. Yu SC, Ho SS, Lau WY, et al. Treatment of
pyogenic liver abscess: prospective randomized
comparison of catheter drainage and needle
aspiration. Hepatology 2004;39:932-8.
17. Chou FF, Sheen-Chen SM, Chen YS, Lee TY.
The comparison of clinical course and results
of treatment between gas-forming and nongas-forming
pyogenic liver abscess. Arch Surg
1995;130:401-5.
18. Lee HL, Lee HC, Guo HR, Ko WC, Chen
KW. Clinical significance and mechanism of
gas formation of pyogenic liver abscess due
to Klebsiella pneumoniae. J Clin Microbiol
2004;42:2783-5.
19. Lee TY, Wan YL, Tsai CC. Gas-containing
liver abscess: radiological findings and clinical
Significance. Abdom imaging 1994;19:47-52.
20. Chen SC, Tsai SJ, Chen CH, et al. Predictors
of mortality in patients with pyogenic liver
abscess. Neth J Med 2008;66:196-203.

18
J Emerg Crit Care Med. Vol. 23, No. 1, 2012
1 2,3-5 1,3
85-95%5-15%
57
1008221001217
1
2 3 4
5
40705160
(04)235925253670(04)23594065
E-mail: song9168@pie.com.tw