Pneumoperitoneum with unperforated acute appendicitis Letters Pneumoperitoneum with Unperforated Acute Appendicitis in a Patient Undergoing Peritoneal Dialysis. Nobuhiro Hieda,1) Tetsuya Makiishi,2,3) Shinya Yamamoto,2,3) Sayako Maeda,2,3) Takashi Konishi3) and Kunihiko Hirose3) 1) Department of Internal Medicine, Division of Gastroenterology, Otsu Red Cross Hospital, Otsu 2) Department of Internal Medicine, Division of Nephrology, Otsu Red Cross Hospital, Otsu 3) Department of Cardiology, Otsu Red Cross Hospital, Otsu Key Words: acute appendicitis, peritoneal dialysis, pneumoperitoneum Gen Med : 2011 ; 12 : 89-90 A 51-year-old man was admitted to our hospital A plain computed tomography（CT）scan of the with worsening abdominal pain, nausea and vomiting abdomen was performed to check for abdominal over the previous 4 hours. He did not have diarrhea pathology. The axial CT scan showed a fluid-filled, and had no history suggestive of food poisoning or dilated appendix with a calcified fecalith in the viral gastroenteritis in his family. He had been on appendiceal neck（Figure 1A). A PDcatheter was peritoneal dialysis（PD）for 7 months because of shown in the same figure. The CT scan also showed chronic renal failure caused by chronic glomerulo- the presence of intra-abdominal free air（Figure 1B), nephritis. Vital signs showed temperature of 36.4℃, which raised the possibility that the appendix might pulse rate of 84 beats per minute, and blood pressure be perforated. Inflammatory changes of the fat, of 140／70 mmHg. The physical examination was however, were limited to the cecum, indicating that significant for rebound tenderness in the right lower the air did not originate from perforation of the quadrant and was positive for McBurney point appendix, but rather from peritoneal dialysis proce- tenderness. Blood tests revealed a white cell count of dure. 14400／ml with left shift. Peritoneal catheter-related When a diagnosis of acute appendicitis is evident in infection was suspected first, but the patient denied a PDpatient, an immediate surgical intervention is cloudiness of the dialysate drained on the morning of recommended to resume PDsuccessfully 1. Therefore, admission. Nevertheless, this did not completely rule open appendectomy was performed on the day of out suspicion. admission to confirm the diagnosis of endoappendici- Author for Corresponding : Tetsuya Makiishi, Department of Internal Medicine, Division of Nephrology, Otsu Red Cross Hospital, Otsu 1-1-35, Nagara, Otsu, Shiga, 520-8511, e-mail: [email protected] Received for publication 1 February 2011 and accepted 20 July 2011 ―89― General Medicine vol. 12 no. 2, 2011 Figure 1A. A plane computed tomography（CT） Figure 1B. The CT scan shows intra-abdominal scan of the abdomen shows a fluid-filled, dilated free air（arrow). appendix with a calcified fecalith in the appendi- ceal neck（arrows), and the peritoneal dialysis catheter（arrowhead). tis, a simple catarrhal inflammation limited to the acute abdomen, an iatrogenic cause must be taken mucosal surface of the vermiform appendix. into consideration as a differential diagnosis. Peritoneal dialysis was restarted successfully after a We declare no conflict of interest. 2-week period of hemodialysis. The patient was discharged on the 14th day after admission. References Diagnosis of surgical abdomen, such as acute 1 Yang, C. Y.; Chuang, C. L.; Shen, S. H.; Chen, T. W.; appendicitis, in a PDpatient is challenging for several Yang, W. C.; Chen, J. Y. Appendicitis in a CAPD reasons. First, differential diagnosis of surgical abdo- patient. Perit Dial Int. 2007, vol. 27, p. 591-593. men from catheter-related infection, most common 2 Miller, R. E.; Nelson, S. W. The roentgenologic cause of bacterial peritonitis in PDpatients, is difficult demonstration of tiny amounts of free intraperitoneal especially when CT scans of the abdomen have no gas; experimental and clinical studies. Am J specific findings. Fortunately, the CT scans in this Roentgenol Radiat Nucl Ther. 1971, vol. 112, p. 574- case showed typical features of acute appendicitis. 585. Second, and an important message from the present 3 Roh, J. J.; Thompson, J. S.; Harned, R. K.; Hodgson, study, intra-abdominal free air can be present in PD P. E. Value of pneumoperitoneum in the diagnosis of patients as a result of PDprocedure. visceral perforation. Am J Surg. 1983, vol. 146, p. 830- Intra-abdominal free air, or pneumoperitoneum, 833. can be detected radiologically with as little as 1 ml of 4 Winek, T. G.; Mosely, H. S.; Grout, G.; Luallin, D. intra-abdominal free air2. This finding usually reflects Pneumoperitoneum and its association with ruptured a perforated abdominal viscus. 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