Could hyponatremia be a marker of anastomotic leakage after colorectal surgery? A single center analysis of 1,106 patients over 5 years.
OBJECTIVE
The aim of this study is to define the significance of hyponatremia as a marker of anastomotic leakage after colorectal surgery.


METHODS
All anastomoses in colorectal surgery performed at a single institution between July 2007 and July 2012 (n = 1,106) were retrospectively identified. Serum sodium levels and leukocyte values measured when an anastomotic leak was diagnosed by CT scan and/or surgical reintervention (n = 81) were compared to the values preferably on postoperative day 5 in the absence of an anastomotic leak (n = 1,025).


RESULTS
The leak rate in anastomoses of the rectum was 9.0 %, while the leak rate of the other anastomoses was 5.4 %. Mean serum sodium level was 138.8 mmol/l in the group with an anastomotic leak and 140.5 mmol/l in the group without. Hyponatremia (<136 mmol/l) was present in 23 % of patients in the group with an anastomotic leak and in 15 % in the group without (p < 0.001). In multivariate analysis, leukocytes and serum sodium level remained as significant markers of an anastomotic leak. As a marker of an anastomotic leak, hyponatremia had a specificity of 93 % and a sensitivity of 23 %, while the presence of either leukocytosis or hyponatremia had a sensitivity of 68 %, a specificity of 75 %, a positive predictive value of 18 %, and a negative predictive value of 97 %.


CONCLUSIONS
Hyponatremia could be a specific and relevant marker of anastomotic leakage after colorectal surgery. If hyponatremia and leukocytosis are present after colorectal surgery, anastomotic leakage should be suspected and a CT scan with rectal contrast dye is recommended.
Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 22, 81675, Munich, Germany, sakaeser@swissonline.ch.
S A
SA
Käser
U
U
Nitsche
M
M
Maak
C W
CW
Michalski
C
C
Späth
T C
TC
Müller
C A
CA
Maurer
K P
KP
Janssen
J
J
Kleeff
H
H
Friess
F G
FG
Bader
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057868:Anastomotic Leak / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000209:etiology*; D007958:Leukocyte Count; D007964:Leukocytosis / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
D015415:Biomarkers