Interventional neuroradiology (INR) has been a rapidly expanding and advancing clinical area during the past few decades. As the complexity and diversity of INR procedures increases, the demand for anesthesia also increases. Anesthesia for interventional neuroradiology is a challenge for the anesthesiologist due to the unfamiliar working environment which the anesthesiologist must consider, as well as the unique neuro-interventional components. This review provides an overview of the anesthetic options and specific consideration of the anesthesia requirements for each procedure. We also introduce the anesthetic management for interventional neuroradiology performed in our medical institution.
Anesthesia ; International Normalized Ratio

BACKGROUND AND OBJECTIVES: To evaluate the accuracy and the clinical utility of the Coaguchek(R) XS, a portable point-of-care coagulometer, compared to standard laboratory methods in Korean patients. SUBJECTS AND METHODS: We included 107 patients with atrial fibrillation on long-term oral warfarin therapy. The prothrombin time as expressed by the international normalized ratio (INR) was measured by the portable Coaguchek(R) XS system as well as standard laboratory methods. Agreement between the two methods was defined as a difference of less than 0.3 between the INR values. RESULTS: The INR determined by the portable Coaguchek(R) XS had excellent correlation with the values obtained by standard methods (r=0.984, p<0.01). The INR determined by the portable Coaguchek(R) XS tended to be high among the high INR group values (standard INR>3.0). There was a 91.6% agreement between the two methods. Only nine cases (8.4%) had a difference of more than 0.3; this was mainly noted in the high INR group. CONCLUSION: The portable self-testing of the INR by the Coaguchek(R) XS might be a reliable alternative to hospital based laboratory testing in Korean patients.
Atrial Fibrillation ; Humans ; International Normalized Ratio ; Prothrombin Time ; Warfarin

BACKGROUND: We investigated changes in the International Normalized Ratio (INR) and its measurement interval in patients with thromboembolic events who were treated by low intensity anticoagulation therapy after isolated mechanical aortic valve replacement. MATERIALS AND METHODS: Seventy-seven patients who underwent surgery from June 1990 to September 2006 were enrolled in the study and observed until August 2008. The patients were followed up at 4~8 week intervals and their warfarin (Coumadin)(R) dosage was adjusted aiming for a target range of INR 1.5~2.5. The rate of thromboembolic events was obtained. Changes in the mean INR and INR measurement interval were comparatively analyzed between the normal group (event free group, N=52) who had no anticoagulation-related complications and the thromboembolic group (N=10). Hospital records were reviewed retrospectively. RESULTS: The observation period was 666.75 patient-years. Thromboembolic events occurred in 10 patients. The linearized occurrence rate of thromboembolism was 1.50%/patient-years. Actuarial thromboembolism-free rates were 97.10+/-2.02% at 5 years, 84.30+/-5.22% at 10 years, and 67.44+/-12.14% at 15 years. The percentages of INR within the target range and mean INR were not statistically significantly different for the normal and thromboembolic groups. However, the mean INR during the segmented period just before the events showed a significantly lower level in the thromboembolic group (during a 4 month period: normal group, 1.86+/-0.14 vs. thromboembolic group, 1.50+/-0.28, p<0.001). The mean intervals of INR measurement during the whole observation period showed no significant differences between groups, but in the segmented period just before the events, the interval was significantly longer in thromboembolic group (during a 6 month period: normal group, 49.04+/-9.47 days vs. thromboembolic group, 65.89+/-44.88 days, p<0.01). CONCLUSION: To prevent the occurrence of thromboembolic events in patients who receive isolated aortic valve replacement and low intensity anticoagulation therapy, we suggest that it would be safe to maintain an INR level above 1.8 and to measure the INR at least every 7~8 weeks.
Aortic Valve ; Hospital Records ; Humans ; International Normalized Ratio ; Thromboembolism ; Warfarin

BACKGROUND: In order to achieve a maintenance level and to prevent hemorrhagic complications, regular monitoring of the INR is mandatory for patients on oral anticoagulation therapy (OAT). A point-of-care instrument for INR monitoring is convenient for users, but the accuracy of the results has been controversial, and so this calls for exact evaluation of the point-of-care instrument that is used for INR monitoring. METHODS: From Aug 2007 through Feb 2008, 85 patients on OAT among the all the patients who were admitted to Soonchunhyang University Bucheon Hospital were involved in this study. Parallel measurements of the PT INR were performed using a CoaguChek-XS and, a CA-7000 laboratory reference instrument and the results were analyzed. In addition, the patients' clinical data, including the diagnosis and the frequency and interval of the INR measurements, were also analyzed. RESULTS: Of the 85 patients, 25 were admitted more than once to undergo INR testing and the mean interval between testing was 8.6 weeks with 39% and 38% of the tests being less than INR 2 units with using the CoaguChek-XS and the reference method, respectively. The coefficients of variation of CoaguChek-XS were 4.50 and 2.45 for the high and low INR patients, respectively. An excellent correlation was found between the two methods with a R2 of 0.966 (p<0.001). Through Bland-Altman analysis, the mean INR difference between the two methods was 0.13 with the limit of agreement being -0.47 +0.72 with a 95% confidence interval. CoaguChek-XS was shown to overestimate the INR value for patients with an increasing INR, as compared to the reference method. CONCLUSION: CoaguChek-XS demonstrated great precision and accuracy for patients on OAT when compared to the laboratory INR results. Accordingly, the instrument should help to monitor the INR in the patients on OAT.
Avena ; Humans ; International Normalized Ratio ; Organothiophosphorus Compounds ; Prothrombin ; Prothrombin Time

Hemothorax in a patient on anticoagulant therapy for atrial fibrillation after blunt trauma is not an uncommon event. However, massive hemothorax in such a patient with an extremely uncontrolled and high international normalized ratio (INR) may pose a serious dilemma. We report a case of a patient under anticoagulant therapy for atrial fibrillation who underwent an emergent thoracotomy for massive hemothorax with an INR of 9.57.
Atrial Fibrillation ; Hemothorax ; Humans ; International Normalized Ratio ; Thoracotomy

Although traditionally fresh frozen plasma (FFP) has been the product of choice for reversing a significant coagulopathy, the modern blood bank will have several different plasma preparations which should all be equally efficacious in reversing a significant coagulopathy or arresting coagulopathic bleeding. Emerging evidence suggests that for a stable patient, transfusing plasma for an INR< or =1.5 does not confer a hemostatic benefit while unnecessarily exposing the patient to the risks associated with plasma transfusion. This review will discuss the various plasma products that are available and present some of the current literature on the clinical uses of plasma.
Blood Banks ; Hemorrhage ; Humans ; International Normalized Ratio ; Plasma

This study aimed to explore the correlation between usual vitamin K intake and response to anticoagulant therapy among patients under warfarin therapy. We conducted a retrospective survey of patients (n = 50) on continuous warfarin therapy. Clinical information and laboratory parameters were sourced from medical records. Anticoagulant effect was evaluated by using the percent time in therapeutic range (TTR) and the coefficient of variation (CV) of International normalized ratio (INR). Dietary vitamin K intake was assessed using a semi-quantitative food frequency questionnaire that has been developed for the purpose of assessing dietary intake of vitamin K. A total of 50 patients aged between 21 and 87 years were included in the study. The mean vitamin K intake was 262.8 +/- 165.2 microg/day. Study subjects were divided into tertiles according to their usual vitamin K intake. The proportion of men was significantly higher in second and third tertile than first tertile (p = 0.028). The mean percent TTR was 38.4 +/- 28.4% and CV of INR was 31.8 +/- 11.8%. Long-term warfarin therapy group (> or = 3 years) had a higher percentage of TTR as compared to the control group (< 3 years) (p = 0.046). No statistically significant correlation was found between usual vitamin K intake and percent TTR (p > 0.05). In conclusion, no significant association was observed between usual vitamin K intake and anticoagulant effects. Further studies are required to consider inter-individual variability of vitamin K intake. Development of assessment tools to measure inter-individual variability of vitamin K intake might be helpful.
Humans ; International Normalized Ratio ; Male ; Medical Records ; Retrospective Studies ; Vitamin K* ; Vitamins* ; Warfarin*

BACKGROUND AND PURPOSE: The quality of anticoagulation is critical for ensuring the benefit of warfarin, but this has been less well studied in Korean ischemic stroke patients with atrial fibrillation (AF). METHODS: This study retrospectively analyzed the data of patients who had an AF-related ischemic stroke and were treated with long-term warfarin therapy in 16 Korean centers. The quality of warfarin therapy was primarily assessed by the time in therapeutic range [TTR; international normalized ratio (INR), 2.0–3.0] and additionally by the proportion of INR values within the therapeutic range. RESULTS: The long-term warfarin-treated cohort comprised 1,230 patients. They were aged 70.1±9.7 years (mean±SD), 42.5% were female, and their CHA₂DS₂-VASc score was 4.75±1.41. The TTR analysis included 33,941 INR measurements for 27,487 months: per patients, 27.6 (SD, 22.4) INR measurements for 22.4 (SD, 12.9) months. The mean TTR of individual patients was 49.1% (95% confidence interval, 47.9–50.3%), and the TTR quartiles were <34.5, 34.5–49.1, 49.1–64.5%, and >64.5%. None of the 16 centers achieved a mean TTR of >60%. Of all INR measurements, 44.6% were within the therapeutic range, 41.7% were <2.0, and 13.7% were >3.0. CONCLUSIONS: In Korean ischemic stroke patients who had AF, the quality of warfarin therapy was low and might be inadequate to effectively prevent recurrent stroke or systemic embolism.
Atrial Fibrillation* ; Cohort Studies ; Embolism ; Female ; Humans ; International Normalized Ratio ; Observational Study* ; Retrospective Studies* ; Stroke* ; Warfarin*

PURPOSE: In cases of patients who underwent bipolar hemiarthroplasty (BPHA) for treatment of a pertrochanteric fracture, we compared and analyzed the amount of blood loss and complications between a group using the cemented stem and a group using the cementless stem. MATERIALS AND METHODS: A total of 104 patients who underwent BPHA for treatment of a pertrochanteric fracture in our hospital for three years and 10 months (From January 2008 to October 2011) were included in this study. Among the 104 patients, 64 patients with a cemented stem were categorized into group 1, and the other 40 patients with an uncemented stem were categorized into group 2. Before surgery, the type of stem was determined by the bone quality of the proximal femur, which had been evaluated with a simple X-ray. Then, after surgery, the amount of blood loss and complications were compared between the two groups. RESULTS: Expected blood loss during the operation was 389.8 cc in group 1, and 395.3 cc in group 2(P=0.88). Postoperatively, average drained blood loss was 219.6 cc in group 1, and 338.1 cc in group 2. Cemented stem was associated with significantly less blood loss (P=0.004). The average operation time in group 1 and in group 2 was 96 minutes and 72 minutes. There was no significant difference in operating time (P=0.85). In addition, there was no difference in INR (International Normalized Ratio) and BMI (Body Mass Index) (P=0.28 and 0.08) regarding total amount of postoperatively drained blood loss. There was no occurrence of hypotensive shock or fatal pulmonary embolism in either group. Three cases of periprosthetic fracture occurred in group 2. CONCLUSION: Fewer occurrences of postoperative blood loss and fewer complications were observed in the cemented stem group than in the cementless stem group. Preoperative evaluation of bone quality and use of the cement stem for patients with poor bone quality may be a good treatment method that can help to reduce complications.
Femur ; Hemiarthroplasty ; Hemorrhage ; Humans ; Hydroxylamines ; International Normalized Ratio ; Periprosthetic Fractures ; Postoperative Hemorrhage ; Pulmonary Embolism ; Shock

BACKGROUND AND OBJECTIVES: Patients on oral anticoagulation therapy (OAT) require regular monitoring of the prothrombin time (PT) and dosage adjustment to prevent thromboembolic diseases without the risk of hemorrhage. Portable self PT monitors have been recently developed because the standard PT measurements are complicated and take considerable time. This study compared the International normalized ratio (INR) results that were obtained with using the CoaguChek XS device (Roche Diagnostic, Mannheim, Germany) with those obtained using a standard laboratory method Sysmex CA-1500 (Sysmex Corporation, Kobe, Japan) in the patients on OAT and also a healthy control group. SUBJECTS AND METHODS: 100 outpatients on OAT and 20 healthy controls were enrolled on a volunteer basis after providing informed consent at the Dong-A University Hospital. The outpatients and the healthy control group provided us the INR measurements with using both the CoaguChek XS and the Sysmex CA-1500. RESULTS: The coefficients of variation for CoaguChek XS and Sysmex CA-1500 were less than 10%. The PT (INR) results of CoaguChek XS and Sysmex CA-1500 were 2.0+/-0.7 and 2.2+/-0.7, respectively (p<0.001). There was a good correlation between CoaguChek XS and Sysmex CA-1500 (r=0.974, p<0.001). On the regression analysis, the slope of the regression line was 0.9197 and the y-intercept was 0.0058. On the Bland-Altman analysis, the INR mean difference (bias) between the two methods (CoaguChek XS INR-Sysmex CA-1500 INR) was -0.2 and the limit of agreement was +0.168~-0.568. CONCLUSION: The measurement with using CoaguChek XS has high repeatability, rapid availability and good accuracy that are comparable to the standard laboratory method. Therefore, CoaguChek XS can be a valuable tool for the self-monitoring of patients on OAT.
Anticoagulants ; Avena ; Hemorrhage ; Humans ; Informed Consent ; International Normalized Ratio ; Outpatients* ; Prothrombin Time* ; Prothrombin* ; Volunteers