特発性血小板減少性紫斑病に対する脾臓摘出後の開心術後に重症感染症をきたした1例

Overwhelming Postsplenectomy Infection after Cardiac Surgery in a Patient with Immune Thrombocytopenia；Report of a Case

はじめに　特発性血小板減少性紫斑病（ITP）の難治例に対し脾臓摘出術が行われるが，莢膜保有菌に対する脆弱性から急激で致死的な脾臓摘出後重症感染症（OPSI）に罹患しやすく，主な起因菌となる肺炎球菌ワクチン（PPV）の接種が推奨されている．われわれは難治性ITP脾臓摘出後の大動脈弁閉鎖不全（AR），冠状動脈狭窄の症例において，PPV接種後，血小板減少に対する術前治療が奏功し周術期に良好な止血を得たが，術後6日目に発熱をきたしOPSIに準じた加療を行った1例を経験したので報告する．

Splenectomy for immune thrombocytopenia （ITP） can increase the number of platelets. However, patients without functioning spleen become vulnerable to bacteria. Overwhelming post-splenectomy infection （OPSI）， its most fulminant form, is rapidly progressive and is highly fatal. A 76-year-old male, who had undergone splenectomy for refractory ITP and taken a vaccination for Streptococcus pneumoniae 4 years previously, was admitted to undergo cardiac surgery for severe aortic regurgitation and coronary disease. Prior to operation, high dose intravenous immunoglobulin therapy （400 mg/kg/day） for 5 days successfully increased platelet count. Surgery and early postoperative course were satisfactory. However, on 6th postoperative day, the patient had sudden high fever and became septic. After adequate antibiotic treatment for OPSI, the patient recovered well. Blood culture yielded methicillin-susceptible Staphylococcus aureus （MSSA）. The patient discharged in good condition 30 days after the operation.