SQU Med J, February 2012, Vol. 12, Iss. 1, pp. 120-123, Epub. 7th Feb 12. Submitted 4th Jul 11 Revision Req. 10th Sep 11, Revision recd. 23rd Nov 11 Accepted 30th Nov 11 Department of Medicine, Sultan Qaboos University Hospital, Muscat, Oman. Corresponding Author e-mail: kowhassan@btinternet.com معاجلة اْلِتهاب الشَّغاِف الَعدوائّي للصّمام األهبر بالبكترييا الزائفة الزجنارية باألدوية عند مريض غسيل الكلى كوثر�سلمان ح�سن، داوؤود الريامي امللخ�ص: التهاب ال�سغاف العدوائي عند مر�سى غ�سيل الكلى عدوى خطرية حتمل ن�سبة وفاة مرتفعة. عادة ما ي�سبب هذا الإلتهاب البكترييا اإيجابية اجلرام ومن النادر اأن ت�سببه البكرتيا �سلبية اجلرام. غالبا ما يت�سمن العالج الناجع ا�ستبدال ال�سمام امل�ساب جراحيا، بالإ�سافة اإىل ال�ستخدام طويل الأجل للم�سادات احليوية، بينما ُيَعد جناح العالج بامل�سادات احليوية وحدها اأمر نادر احلدوث. يف هذا التقرير ن�سف حالة التهاب ال�سغاف الَعدوائي بالبكترييا الزائفة الزجنارية يف مري�س على غ�سيل الكلى عولج بامل�سادات احليوية لوحدها. مفتاح الكلمات: الزائفة الزجنارية، التهاب ال�سغاف الَعدوائي، غ�سيل الكلى، املعاجلة بامل�سادات احليوية، تقرير حالة، ُعمان. abstract: Infective endocarditis (IE) in patients on dialysis is a serious infection with a high mortality rate. It is usually caused by Gram positive bacteria with Gram negative organisms being relatively rare as a cause. Recommended treatment usually involves surgical valve replacement and the extended use of antibiotics. Successful treatment with antibiotics alone is rare. We report a case of IE caused by Pseudomonas aeruginosa in a patient on dialysis treated solely with antibiotics. Keywords: Pseudomonas aeruginosa; Infective endocarditis; Dialysis; Treatment, antibiotic; Case report; Oman. Infective Endocarditis of the Aortic Valve caused by Pseudomonas aeruginosa and Treated Medically in a Patient on Haemodialysis *Kowthar S. Hassan and Dawood Al-Riyami CASE REPORT Infective endocarditis caused by Pseudomonas aeruginosa is rarely seen in clinical practice. It has been reported mainly in intravenous (IV) drug abusers.1,2 P. aeruginosa is also an occasional cause of nosocomial endocarditis, accounting for 10% of cases in one small intensive care unit (ICU) series.3 It carries a very high mortality rate of 80% necessitating, therefore, early diagnosis and intervention. The clinical outcome of right-sided endocarditis has improved with cure rates reaching 84% while that of the left side remains 33%.4 This sub- optimal outcome is partly due to increasing resistance to beta-lactams and aminoglycosides.1,4,5 Fluoroquinoloes, on the other hand, seem to be more potent against Pseudomonas.6,7 Numerous studies have shown significantly better outcomes with combined medical/surgical treatment.8-11 We report a haemodialysis patient who developed aortic regurgitation following catheter related P. aeruginosa endocarditis and describe her medical management and the outcome. Case report A 49 year-old Omani woman on dialysis with a past medical history of hypertension, diabetes, coronary artery disease, and end-stage renal disease presented to our hospital with uraemia. She was started on maintenance haemodialysis via a right internal jugular tunnelled cuffed catheter. A week later she had placement of an arteriovenous fistula (AVF). Kowthar S. Hassan and Dawood Al-Riyami Case Report | 121 Two weeks following the insertion of the catheter she developed fever and generalised weakness. Blood cultures taken from the central line grew P. aeruginosa. She was treated with ciprofloxacin and tazocin. She improved on this treatment and the tazocin was changed to amikacin after each dialysis. Subsequent surveillance blood cultures after 4 and 6 weeks of the first blood culture were negative. She was investigated with transthoracic echocardiography which reported no evidence of thrombi or vegetations. Given that her AVF was maturing and could be potentially used for dialysis only a month after the bacteraemia, the central line was kept for dialysis. However, one week later, before the line was removed, she presented with fever, generalised weakness, sore throat and dry cough. Her examination revealed a temperature of 37.9°C, blood pressure of 180/70 mmHg, mild pedal oedema and no signs of inflammation on the skin overlying the tunnelled catheter, but mild crusting at the exit site. Her body weight was 65 kg. Her systemic examination was remarkable for a new diastolic murmur. Her investigations reported normal white blood cell (WBC) count and her chest X-ray reported no pneumonia. She continued to be sick and febrile despite initial management of presumed community-acquired pneumonia. At this stage, a catheter related infection was presumed and she was treated with vancomycin and amikacin. The tunnelled catheter was removed as her AVF was ready to be used for dialysis. Blood cultures grew P. aeruginosa. Transthoracic echocardiography (TTE) showed a well-circumscribed small mass attached to the non-coronary and right coronary cusp of the aortic valve suggestive of vegetation [Figure 1]. Transoesophageal echocardiography showed a huge vegetation of 2 cm on the left and non-coronary cusps of the aortic valve with no aortic root abscess. The cardiothoracic surgeon suggested valve replacement in addition to medical management with ceftazidime and amikacin. However, the patient strongly refused the surgery. On medical treatment alone she showed a remarkable improvement. TTE was done one month post antibiotics commencement. It showed evidence of severe aortic regurgitation (AR) and mobile vegetation attached mostly to the right coronary cusp. The large vegetation on the non- Figure 1: Apical view transthoracic echocardiography scan showing large vegetation seen on the aortic valve. Figure 2: Apical view transesophageal echocardiography scan showing decrease in the size of previous vegetation. Figure 3: Short axis, aortic view echocardiography scan showing total clearance of the vegetation. Infective Endocarditis of the Aortic Valve caused by Pseudomonas aeruginosa and Treated Medically in a Patient on Haemodialysis 122 | SQU Medical Journal, February 2012, Volume 12, Issue 1 coronary cusp was no longer seen and only small vegetation was seen on the left corornary cusp [Figure 2]. A repeat echocardiography 2 weeks later showed a mildly thickened aortic valve, but no vegetation [Figure 3]. In the last follow-up, one year later, the patient continued to do well clinically. Discussion Pseudomonas bacteraemia is a nosocomial problem being the third most frequent cause of Gram negative bacteraemia.12 Our patient had a central line which was the culprit for her bacteraemia and subsequent endocarditis. Endocarditis caused by this pathogen is very serious with a very high mortality rate.13 Patients with left-sided valvular infections, often develop rapidly progressive symptoms that are due to either congestive heart failure or an embolism of large or medium-sized arteries. Ring and annular abscesses are also frequent complications. Pseudomonas endocarditis is associated with high mortality. This is explained by the fact that beta-lactams have a slow bactericidal effect on the organism and resistance to the drugs develops rapidly. Thus, treatment of P. aeruginosa endocarditis usually necessitates the combination of antibiotics and surgery to achieve a cure.14 Valve replacement was offered to our patient, but she persistently refused any surgical interventions. She was managed with a combination of ceftazidime (1 g three times a day) and amikacin (500 mg once/ day, on three days of week with dialysis, to achieve trough levels below 5 mg/L and peak levels between 20–30 mg/L). After ten weeks the vegetation had completely disappeared. Medical treatment alone in left-sided infective endocarditis caused by P. aeruginosa was previously reported to be successful.15 Conclusion We reported the cure of a case of endocarditis caused by P. aeruginosa with ceftazidime and amikacin. In the case of catheter related bacteremia with Pseudomonas, the line should be removed as soon as possible. a c k n o w l e d g e m e n t We thank Dr. Hatem L Farhan for his effort in translating the abstract into Arabic. References 1. Reyes MP, Lerner AM. Current problems in the treatment of infective endocarditis due to Pseudomonas aeruginosa. Rev Inf Dis 1983; 5:314-21. 2. Reyes MP, Ali A, Mendes RE, Biedenbach DJ. Resurgence of Pseudomonas endocarditis in Detroit 2006-2008. Medicine (Baltimore) 2009; 88:294–301. 3. Gouello JP, Asfar P, Brenet O, Kouatchet A, Berthelot G, Alquier P. Nosocomial endocarditis in the intensive care unit: an analysis of 22 cases. 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