The Method to Increase the Ratio of Location of a Catheter in the Superior Vena Cava by Subclavian Cannulation / 대한마취과학회지

BACKGROUND: Subclavian cannulation is useful for the patients who need long-term maintenance of central venous catheters, but the inadequate location of catheters produces some complications. In pediatric populations, the abnormal placement of subclavian catheters in the internal jugular vein (IJV) is frequent because the angle formed by the subclavian vein and IJV is much larger than in adults. We would therefore propose a technique which will increase the location ratio of subclavian catheters in the superior vena cava (SVC). METHODS: One hundred twenty three patients who received elective or emergent operations were divided into 4 groups which consisted of the 'neck rotation away from the cannulation site' group (RA), 'neck rotation toward the cannulation site' group (RT), 'neck tilt away from the cannulation site' group (TA), 'neck tilt toward the cannulation site' group (TT). We cannulated each group and verified the location of the catheter tip in chest PA for each group. RESULTS: The calculation for the ratio of SVC location to the total cannulation of each group (%SVC) was done and the X2 test was done. Total %SVC was 73.2% and %SVC of each group were 64.9% for the RA group, 77.3% for the RT group, 61.8% for the TA group, and 93.3% for the TT group. A considerable difference was found for total %SVC in the X2 test. The location ratio of the TT group was higher than the others and there was no difference found between the RA, RT, TA groups. CONCLUSIONS: We can conclude that tilting the neck toward the cannulation site would produce a higher ratio of SVC location of the subclavian catheter than other neck positions.

Changes of Thrombelastography in Acute Isovolemic Hemodilution Undergoing Total Hip Replacement Arthroplasty / 대한마취과학회지

BACKGROUND: Acute isovolemic hemodilution is one of the autologous transfusion which diminishes intraoperative blood loss and avoids homologous transfusion. A method of assessment of hemostatic function by whole blood is thrombelastography, which is a sensitive indicator of platelet interreaction with protein coagulation cascade. We investigated the effect of intraoperative isovolemic hemodilution on blood coagulation as measured by thrombelastography. METHODS: We studied in twenty-one patients undergoing elective total hip replacement arthroplasty. Hemodilution was done with Hartmann's solution and pentastarch and prothrombin time, activated partial thromboplastin time and native whole blood thrombelastography were performed preoperatively, immediate postoperative and days 2 postoperatively. RESULTS: The Hb, Hct and platelet count decreased significantly after hemodilution. The thrombelastographic changes included decreases in r and k with concurrent increases in alpha angle and MA in immediate postoperative time. On days 2, there were further increase in alpha angle and MA. These changes indicate enhanced procoagulant activity and progressive increase in maximum clot strength. Conclusion: Acute isovolemic hemodilution with Hartmann's solution and pentastarch induced hypercoagulable state without any serious complication in total hip replacement arthroplastic surgery.