Ultrasound visibility of regional anesthesia catheters: an in vitro study / 대한마취과학회지

BACKGROUND: Ultrasound subjective visibility of in-plane needles is correlated with the intensity difference between the needle surface and the background. Regional anesthesia catheters are difficult to visualize by an ultrasound. In the present study, we investigated the ultrasound visibility of the catheters. METHODS: Six catheters were placed at 0degrees and 30degrees relative to and at a depth of 1 cm below the pork phantom surface. Ultrasound images of in-plane catheters were evaluated, subjectively and objectively. Outer and inner objective visibilities were defined as the difference in the mean pixel intensity between the catheter surface and adjacent background, and between the surface and the center of the catheter, respectively. Evaluations were made based on the portion of the catheters. A P value < 0.05 was considered significant. RESULTS: Subjective visibility was more strongly correlated with the inner objective visibility than with the outer objective visibility at both angles. Metallic 19-gauge catheters were more subjectively visible than the non-metallic 20-gauge catheters at 30degrees degrees (P < 0.01). Subjective, and outer and inner objective visibility were significantly lower at 30degrees than at 0degrees (P < 0.01, P < 0.01, P = 0.02). Perifix ONE at 0degrees and Perifix FX at 30degrees were the most visible catheters (P < 0.01 for both). CONCLUSIONS: Subjective visibility of catheters can not be evaluated in the same manner as that of the needles. For the best possible visualization, we recommend selecting a catheter with a structure that enhances the dark at the center of catheter, rather than basing the catheter selection on the bore size.

Use of perioperative ureteral stent in abdominal aortic aneurysm with retroperitoneal fibrosis: A report of two cases / 대한마취과학회지

Retroperitoneal fibrosis is associated with fibroblast proliferation due to inflammatory changes in adipose/fibrous tissue. Given that aortic dilation in abdominal aortic aneurysm can cause compression of the ureter, abdominal aortic aneurysm complicated by retroperitoneal fibrosis is likely to result in urinary tract obstruction. Accordingly, close attention to changes in perioperative urine volume is warranted when operating on patients with abdominal aortic aneurysm complicated by retroperitoneal fibrosis. We have recently performed laparotomies on two cases of abdominal aortic aneurysm complicated by retroperitoneal fibrosis. In the first case, surgery was performed without the placement of a ureteral stent. The patient developed postrenal acute renal failure caused by postoperative urinary retention. In the second case, ureteral stent placement in advance enabled perioperative management without complications. The clinical course of these cases suggests that, in laparotomy with concomitant retroperitoneal fibrosis, preoperative ureteral stent placement can prevent postoperative complications in the renal and urinary systems.

Experience with an integrated seminar program on community medicine for high school students / 医学教育

We held an integrated seminar program on community medicine for high school students. We used questionnaires to evaluate the usefulness of the seminar.<br>1)The seminar included lectures about community medicine, active–learning programs, and discussions about medical issues.<br>2)Before the seminar, 96% of the participants had been interested in a career in medicine.<br>3)After the seminar, 96% of participants were satisfied with the seminar.<br>4)The number of the participants who wanted to work in the community in Oita in the future increased from 43% before the seminar to 62% after the seminar.<br>Our results suggest that this integrated seminar program is useful for getting high school students interested in community medicine.

Use of Imaging Agent to Determine Postoperative Indwelling Epidural Catheter Position

BACKGROUND: Epidural anesthesia is widely used to provide pain relief, whether for surgical anesthesia, postoperative analgesia, treatment of chronic pain, or to facilitate painless childbirth. In many cases, however, the epidural catheter is inserted blindly and the indwelling catheter position is almost always uncertain. METHODS: In this study, the loss-of-resistance technique was used and an imaging agent was injected through the indwelling epidural anesthesia catheter to confirm the position of its tip and examine the migration rate. Study subjects were patients scheduled to undergo surgery using general anesthesia combined with epidural anesthesia. Placement of the epidural catheter was confirmed postoperatively by injection of an imaging agent and X-ray imaging. RESULTS: The indwelling epidural catheter was placed between upper thoracic vertebrae (n = 83; incorrect placement, n = 5), lower thoracic vertebrae (n = 123; incorrect placement, n = 5), and lower thoracic vertebra-lumbar vertebra (n = 46; incorrect placement, n = 7). In this study, a relatively high frequency of incorrectly placed epidural catheters using the loss-of-resistance technique was observed, and it was found that incorrect catheter placement resulted in inadequate analgesia during surgery. CONCLUSIONS: Although the loss-of-resistance technique is easy and convenient as a method for epidural catheter placement, it frequently results in inadequate placement of epidural catheters. Care should be taken when performing this procedure.

Successful Veno-Arterial Bypass Support Using Centrifugal Pump with Membranous Artificial Oxygenator in a Case of Cardiogenic Shock Following Coronary Artery Bypass Surgery for Acute Myocardial Infarction / 日本心臓血管外科学会雑誌

A 54-year-old man developed cardiogenic shock after acute myocardial infarction. Urgent coronary angiogram revealed complete occlusion at proximal portion of the right coronary artery and severe stenosis at just proximal site of the left anterior descending branch. Following thrombolytic therapy was not successful and he was sent to the operating room for coronary artery bypass surgery under external cardiac massage after 6hr from the onset. Three aorto-coronary bypasses were made to left anterior descending branch, first diagonal branch and right coronary artery using saphenous vein grafts by aortic cross-clamping of 67min. He fell into severe low cardiac output syndrome and could not be weaned from the cardiopulmonary bypass even by catecholamine infusions and IABP support. Veno-arterial bypass consisted of centrifugal pump and membranous artificial oxygenator was instituted. Venous blood was drained from the right atrium using percutaneous cannula via the right femoral vein and oxygenated blood was returned to the right subclavian artery. Hemodynamics recovered dramatically and after 71hr of this assisted circulation he was weaned from veno-arterial bypass. Activated coagulation time was maintained within 180-200sec. During this period, the centrifugal pump and oxygenator was not necessary to change and no clot was seen in the bypass system. He discharged from our hospital after 2 mo, postoperatively and now he is doing well as NYHA class-II 8 mo. postoperatively.