Eur J Pediatr Surg
DOI: 10.1055/s-0039-1687870
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Low Plasma Sodium Concentration Predicts Perforated Acute Appendicitis in Children: A Prospective Diagnostic Accuracy Study

1  Department of Pediatric Perioperative Medicine and Intensive Care, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
2  Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
,
Markus Almström
3  Department of Pediatric Surgery, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
4  Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
,
Johannes Jacks
1  Department of Pediatric Perioperative Medicine and Intensive Care, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
,
Pia Malmquist
5  Department of Pediatric Emergency Medicine, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
,
Per-Arne Lönnqvist
1  Department of Pediatric Perioperative Medicine and Intensive Care, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
2  Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
,
Boye Lagerbon Jensen
6  Department of Cardiovascular- and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
,
Mattias Carlström
2  Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
,
Rafael Tomas Krmar
2  Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
,
Jan Fredrik Svensson
3  Department of Pediatric Surgery, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
4  Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
,
Åke Norberg
7  Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital Huddinge, Stockholm, Sweden
8  Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
,
Urban Fläring
1  Department of Pediatric Perioperative Medicine and Intensive Care, Astrid Lindgren Children’s Hospital, Karolinska University Hospital Solna, Stockholm, Sweden
2  Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
› Author Affiliations
Further Information

Publication History

21 December 2018

09 March 2019

Publication Date:
25 April 2019 (eFirst)

Abstract

Background Early differentiation between perforated and nonperforated acute appendicitis (AA) in children is of major benefit for the selection of proper treatment. Based on pilot study data, we hypothesized that plasma sodium concentration at hospital admission is a diagnostic marker for perforation in children with AA.

Materials and Methods This was a prospective diagnostic accuracy study, including previously healthy children, 1 to 14 years of age, with AA. Blood sampling included plasma sodium concentration, plasma glucose, base excess, white blood cell count, plasma arginine vasopressin (AVP), and C-reactive protein.

Results Eighty children with histopathologically confirmed AA were included in the study. Median plasma sodium concentration on admission in patients with perforated AA (134 mmol/L, [interquartile range 132–136]) was significantly lower than in children with nonperforated AA (139 mmol/L, [137–140]). The receiver operating characteristic curve of plasma sodium concentration identifying patients with perforated AA showed an area under the curve of 0.93 (95% confidence interval, 0.87–0.99), with a sensitivity and specificity of 0.82 (0.70–0.90) and 0.87 (0.60–0.98), respectively. Plasma sodium concentrations ≤136 mmol/L resulted in an odds ratio of 31.9 (6.3–161.9) for perforation. The association between low plasma sodium concentration and perforated AA was confirmed in a multivariate logistic regression analysis. Median plasma AVP on admission was higher in patients with perforated (8.6 pg/mL [5.0–14.6]) as compared with nonperforated AA (3.4 pg/mL [2.5–6.6]).

Conclusion In children with AA, there is a strong association between low plasma sodium concentration and perforation, a novel and not previously described finding.