A Case of Significant Coagulopathy Due to Vitamin K Deficiency Caused by the Administration of Cefazolin and Rifampicin and Hyponutrition After a Postoperative Infection of the Lumbar Spine.

Postoperative surgical site infection in the lumbar spine is one of the serious complications that sometimes results in death. Herein, we describe a case in which a patient was found to have coagulopathy due to vitamin K deficiency when he was transferred to a hospital for treatment for a postoperative infection of the lumbar spine. The coagulation disorder was caused by antimicrobial agents administered to the patient, who was suffering from hyponutrition. The patient was a 70-year-old man with a history of diabetes mellitus. He was diagnosed with lumbar spinal canal stenosis and underwent posterior decompression of the L2-L5 and S1 laminae at a previous hospital five months before transfer to our hospital. Four months before transfer, purulent discharge was observed from the wound, and methicillin-susceptible was detected in the wound culture. Cefazolin was administered for two weeks, resulting in initial improvement. However, one month before the transfer, the wound infection recurred, accompanied by bacteremia and a psoas abscess. He had been treated with cefazolin, levofloxacin, rifampicin, trimethoprim, and sulfamethoxazole, but the antibiotics' effects were insufficient. Upon transfer for debridement surgery due to uncontrolled infection, his coagulation parameters were as follows: prothrombin time (PT) 74.0 sec, PT-international normalized ratio (INR) 6.69, PT% 9.0, activated partial thromboplastin time (APTT) 138 sec, fibrinogen (FIB) 664 mg/dl, fibrin degradation products (FDP) 7.1 μg/ml, and protein induced by vitamin K absence-II (PIVKA-II) 34400 mAU/ml. Because we suspected vitamin K deficiency, vitamin K 40 mg was administered as a test dose, and coagulation function improved to PT 16.4 sec, PT-INR 1.30, PT% 65.2, and APTT 79 sec after four hours. The diagnosis of vitamin K deficiency was confirmed, vitamin K was administered for four days, and the coagulation status normalized five days after transfer. Debridement was performed for the left psoas abscess. Cefazolin was administered for eight weeks, and administration was completed. The coagulation abnormality did not recur due to careful attention to his nutrition. We experienced a case of coagulopathy due to vitamin K deficiency caused by antimicrobial agents administered to a hyponourished patient with a postoperative infection of the lumbar spine. The cause of vitamin K deficiency, in this case, was thought to be low nutrition, suppression of vitamin K-producing bacteria by cefazolin and rifampicin, and the use of cefazolin with a methyl-thiadiazole thiol group. It should be kept in mind that severe coagulopathy due to vitamin K deficiency caused by antimicrobial treatment with hyponutrition can occur in postoperative infections.