Abstract Introduction Peritonitis is the most frequent complication of peritoneal dialysis. Diagnosis of peritonitis includes symptoms and signs of peritonitis with a cloudy aspirate of more than 100 WBC/ml, as well as positive cultures. Although sterile peritonitis has been reported in the literature, to the best of our knowledge this is the first report of an unusual presentation of peritonitis without any white blood cells in the peritoneal aspirate despite multiple positive peritoneal cultures. Case presentation An 82-year-old Caucasian man who had been on continuous cycling peritoneal dialysis for 12 years was admitted to our hospital with general malaise, loss of appetite, weight loss and somnolence. He did not describe abdominal pain or fever. Even though his peritoneal fluid was consistently negative for leukocytes and clear, he had peritonitis with different organisms consecutively. Conclusions Our case report shows that any patient on peritoneal dialysis presenting with evidence of infection (fever, peripheral leukocytosis) without an obvious cause should have aspirate cultures done even if the aspirate is clear and abdominal pain is absent. Our case report may change the initial work-up and management of these patients. We believe this report is of interest to general medicine and emergency room physicians as well as nephrologists.</p

Arzu Kahveci

Atilla Bulur

BM Males

CC Szeto

Cetin Ozener

DG de Freitas

Ebru Asicioglu

Elif Ari Bakir

G Taylor

HA Ludlam

Hakki Arikan

JG Koopmans

L Troidle

Mehmet Koc

SC Huen

Serhan Tuglular

English

PubMed

Springer - Publisher Connector

CASE REPORT Open Access
Unusual presentation of peritonitis with
persistent clear aspirate: a case report
Ebru Asicioglu1*, Arzu Kahveci1, Elif Ari Bakir1, Atilla Bulur2, Hakki Arikan1, Mehmet Koc1, Serhan Tuglular1,
Cetin Ozener1
Abstract
Introduction: Peritonitis is the most frequent complication of peritoneal dialysis. Diagnosis of peritonitis includes
symptoms and signs of peritonitis with a cloudy aspirate of more than 100 WBC/ml, as well as positive cultures.
Although sterile peritonitis has been reported in the literature, to the best of our knowledge this is the first report
of an unusual presentation of peritonitis without any white blood cells in the peritoneal aspirate despite multiple
positive peritoneal cultures.
Case presentation: An 82-year-old Caucasian man who had been on continuous cycling peritoneal dialysis for 12
years was admitted to our hospital with general malaise, loss of appetite, weight loss and somnolence. He did not
describe abdominal pain or fever. Even though his peritoneal fluid was consistently negative for leukocytes and
clear, he had peritonitis with different organisms consecutively.
Conclusions: Our case report shows that any patient on peritoneal dialysis presenting with evidence of infection
(fever, peripheral leukocytosis) without an obvious cause should have aspirate cultures done even if the aspirate is
clear and abdominal pain is absent. Our case report may change the initial work-up and management of these
patients. We believe this report is of interest to general medicine and emergency room physicians as well as
nephrologists.
Introduction
Peritonitis is the most frequent complication of perito-
neal dialysis (PD). Diagnosis of peritonitis includes
symptoms and signs of peritonitis with a cloudy aspirate
of more than 100 WBC/ml, as well as positive cultures.
Although sterile peritonitis has been reported in the lit-
erature [1], to the best of our knowledge this is the first
report of an unusual presentation of peritonitis without
any white blood cells in the peritoneal aspirate despite
multiple positive peritoneal cultures.
Case presentation
An 82-year-old Caucasian man who had been on con-
tinuous cycling peritoneal dialysis (CCPD) for 12 years
was admitted to our hospital with general malaise, loss
of appetite, weight loss and somnolence. He did not
describe abdominal pain or fever. His medical history
included renal failure due to nephrolithiasis and he had
not experienced peritonitis before. His physical exami-
nation was unremarkable and he was experiencing no
abdominal tenderness at the time of his admission. His
white blood cell count was 9600/ml with 80 percent
neutrophils. His C-reactive protein (CRP) level was 118
mg/L (Normal range: 0-5 mg/L). His blood cultures
were negative. He was started on ampicillin and sulbac-
tam and ciprofloxacin treatment empirically. Even
though his peritoneal fluid was clear and there were not
any leukocytes present, peritoneal fluid cultures taken
on admission revealed Pseudomonas aeruginosa. The
ampicillin and sulbactam was switched to piperacillin
and tazobactam and ciprofloxacin treatment was contin-
ued since the isolate was sensitive to both. Two weeks
after his admission, he developed a cough with sputum
production. There was a new infiltration on his chest X-
ray consistent with pneumonia and his CRP level
increased from 32 mg/L to 152 mg/L. He was switched
to imipenem and vancomycin therapy. He still did not
describe abdominal pain or fever and there was no
* Correspondence: easicioglu@yahoo.com
1Department of Nephrology, Marmara University School of Medicine,
(Tophanelioglu Cad.), İstanbul, (34660), Turkey
Full list of author information is available at the end of the article
Asicioglu et al. Journal of Medical Case Reports 2010, 4:383
http://www.jmedicalcasereports.com/content/4/1/383 JOURNAL OF MEDICAL
CASE REPORTS
© 2010 Asicioglu et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
abdominal tenderness on physical examination. Even
though the peritoneal fluid count did not show any leu-
kocytes, a control peritoneal fluid culture revealed Ste-
notrophomonas maltophilia which was sensitive to
trimethoprim-sulfamethoxazole. Trimethoprim-sulfa-
methoxazole was added to treatment. Despite treatment
with imipenem, vancomycin and trimethoprim-sulfa-
methoxazole for two weeks, his condition deteriorated
rapidly and he developed septic shock. While analysis of
his peritoneal fluid was still negative for white blood
cells, peritoneal cultures obtained during the septic
shock revealed vancomycin-resistant Enterococcus fae-
cium (VRE). His blood cultures were negative, however
stool cultures also revealed VRE. He was started on line-
zolide therapy however his condition deteriorated
rapidly and he died six weeks after hospitalization.
Discussion
Peritonitis causes significant morbidity and mortality in
PD patients. It can result in death either from sepsis or
from ensuing complications. Gram-positive organisms,
especially Staphylococcus epidermidis and Staphylococcus
aureus, are the most common bacteriologic causes of
peritonitis. Recently, the incidence of Gram-positive
infections has decreased due to newer techniques and
improved exit-site care, while the incidence of Gram-
negative organisms has remained stable [2]. Gram-nega-
tive organisms now account for 20 to 30 percent of all
peritonitis episodes [3]. Patients with Gram-negative
peritonitis have a worse outcome, are more likely to be
hospitalized and more likely to die within six months
after peritonitis [2]. In our case report, peritoneal fluid
cultures yielded three different organisms consecutively.
The first organism was P. aeruginosa which is one of
the most important causes of Gram-negative peritonitis
and is identified in 7.1 percent of culture positive cases
[3]. The major risk factors for infection are a history of
antibiotic therapy within 30 days and concomitant exit-
site infection [3]. Our patient did not have any risk fac-
tors for this infection. The second microorganism was
Stenotrophomonas maltophilia which is an environmen-
tal saprophyte that has been rarely reported to cause
peritonitis. The annual rate of isolation for this organ-
ism is not known since it has only been reported as case
reports. It is mainly a nosocomial pathogen and is resis-
tant to multiple antibiotics [4]. It can be isolated from
water, soil, hospital equipment and humans. The major
risk factors include prior broad-spectrum antibiotic use,
neutropenia, underlying illness and prolonged hospital
stay [4]. The patient described in this case report had
risk factors for this organism, such as prolonged antibio-
tic use and hospital stay. The third microorganism was
VRE, which was first described in the 1980 s and has
since become increasingly prevalent, causing infections
that include PD-associated peritonitis [5]. However, the
annual rate of isolation is not known. Risk factors for
VRE include severe underlying disease, immunosuppres-
sion, prior use of vancomycin and other antibiotics,
abdominal or cardiothoracic surgery and indwelling
urinary or central venous catheters [6]. Patient had mul-
tiple risk factors for VRE infection, such as vancomycin
use and prolonged hospital stay. The persistent growth
of organisms in his peritoneal culture and his lack of
response to antibiotic therapy warranted early removal
of the catheter. Failure to respond to antibiotic therapy
necessitating early catheter removal is common in
patients with S. maltophilia and/or VRE peritonitis. Our
patient was repeatedly advised immediate surgical
removal of his PD catheter due to the risk of septic
shock and death; however, he refused to undergo the
procedure despite regular counseling
The majority of patients with peritonitis have cloudy
fluid and abdominal pain. The diagnosis is confirmed by
a dialysate aspirate leukocyte count exceeding 100
WBC/ml with at least 50 percent polymorphonuclear
leukocytes. A small percentage of patients do not have
white blood cells in the peritoneal fluid at presentation
with cell counts increasing in time; this is called an
impaired initial cell reaction [7]. This delay may be due
to slower cytokine response to infection [7]. Peritonitis
episodes with cell counts less than 100 WBC/ml have
been reported in the literature [8,9]. However, peritoni-
tis without abdominal pain and/or white blood cells in
the peritoneal fluid is an extremely rare entity and to
the best of our knowledge, this is the first report of a
case of peritonitis with a persistently clear aspirate with-
out any white blood cells. The peritoneal fluid cultures
of our case report yielded different organisms consecu-
tively, however the peritoneal cell counts were consis-
tently nil. It can be argued that the positive cultures in
the absence of increased white blood cell count in the
peritoneal fluid could be indicative of colonization or
improper culture collection. The method used for peri-
toneal culture at our center is as follows: sediment
obtained after centrifugation of 100 ml of fluid is inocu-
lated into aerobic and anaerobic Bactec bottles, on aero-
bic and anaerobic blood, chocolate and MacConkey agar
plates. Gram and Giemsa stains are also performed. It is
highly unlikely that the only three improper cultures
collected at our center so far have been in the same
patient. A low white blood cell count in peritoneal fluid
in the presence of antibiotic use has been reported.
However, since the first organism was isolated before
the use of any antibiotic therapy and the consecutive
organisms were both resistant to the antibiotic therapy
administered at that time, it is not possible to explain
the absence of white blood cells by prior therapy.
Immunosuppression is another possible mechanism for
Asicioglu et al. Journal of Medical Case Reports 2010, 4:383
http://www.jmedicalcasereports.com/content/4/1/383
Page 2 of 3
the lack of white blood cells in our case report; however,
he did not have any disease, condition or any other
laboratory values indicating that he was indeed
immunosuppressed.
We believe our case report demonstrates that clear
aspirate and the absence of white blood cells in the peri-
toneal fluid may not rule out the presence of peritoneal
infection in patients on PD. Therefore, any patient on
PD presenting with evidence of infection (fever, periph-
eral leukocytosis) without an obvious cause should have
aspirate cultures done even if the aspirate is clear and
abdominal pain is absent.
Conclusions
Patients on PD presenting with evidence of infection
(fever, peripheral leukocytosis) without an obvious cause
should have aspirate cultures done even if the aspirate is
clear and abdominal pain is absent.
Consent
Written informed consent was obtained from the
patient’s next of kin for publication of this case report
and any accompanying images. A copy of the written
consent is available for review by the Editor-in-Chief of
this journal.
Author details
1Department of Nephrology, Marmara University School of Medicine,
(Tophanelioglu Cad.), İstanbul, (34660), Turkey. 2Department of Internal
Medicine, Marmara University School of Medicine, (Tophanelioglu Cad.),
İstanbul, (34660), Turkey.
Authors’ contributions
EA, AK, EAB, AB and HA made substantial contributions to the design, and
the acquisition and interpretation of data. MK, ST and CO revised the
manuscript critically for important intellectual content. All authors read and
approved the final manuscript.
Competing interests
The authors declare that they have no competing interests.
Received: 16 December 2009 Accepted: 28 November 2010
Published: 28 November 2010
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doi:10.1186/1752-1947-4-383
Cite this article as: Asicioglu et al.: Unusual presentation of peritonitis
with persistent clear aspirate: a case report. Journal of Medical Case
Reports 2010 4:383.
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