Validation of the minimal citrate tube fill volume for routine coagulation tests on ACL TOP 500 CTS®.

INTRODUCTION: CLSI recommends a minimal citrate tube fill volume of 90%. A validation protocol with clinical and analytical components was set up to determine the tube fill threshold for international normalized ratio of prothrombin time (PT-INR), activated partial thromboplastin time (aPTT) and fibrinogen. METHODS: Citrated coagulation samples from 16 healthy donors and eight patients receiving vitamin K antagonists (VKA) were evaluated. Eighty-nine tubes were filled to varying volumes of >50%. Coagulation tests were performed on ACL TOP 500 CTS(®) . Receiver Operating Characteristic (ROC) plot, with Total error (TE) and critical difference (CD) as possible acceptance criteria, was used to determine the fill threshold. RESULTS: Receiving Operating Characteristic was the most accurate with CD for PT-INR and TE for aPTT resulting in thresholds of 63% for PT and 80% for aPTT. By adapted ROC, based on threshold setting at a point of 100% sensitivity at a maximum specificity, CD was best for PT and TE for aPTT resulting in thresholds of 73% for PT and 90% for aPTT. For fibrinogen, the method was only valid with the TE criterion at a 63% fill volume. CONCLUSION: In our study, we validated the minimal citrate tube fill volumes of 73%, 90% and 63% for PT-INR, aPTT and fibrinogen, respectively.

Efficacy and safety of oral tramadol and pentazocine for postoperative pain following prolapsed intervertebral disc repair.

In this multicenter double-blind randomized study the analgesic efficacy and safety of 50 mg tramadol was compared against 50 mg pentazocine by mouth in the treatment of 160 patients with acute pain following prolapsed intervertebral disc repair. The day of surgery patients were treated with parenteral opioids. The study started the morning after surgery. A wash out period of four hours was allowed after parenteral analgesics. Pain assessment was made using a visual analogue scale (VAS) and a verbal rating scale (VRS) during a six hours observation period. Remedication with the same drug at the same dosage was allowed if pain relief was unsatisfactory. Overall analgesic activity and spontaneously reported side effects were also registered. Results showed both treatments provided equivalent effective analgesia for the six hours observation period. The global assessment of analgesia by patient and observer was not significantly different for both treatments, although less additional medication was required in the pentazocine group. Side effects were quite common in both groups, and occurred more frequently in the pentazocine group.