Biomedical subjects

Hyun Joo Ahn

Publications and source records attributed to Hyun Joo Ahn.

7 recordsLinked to original sources

PubMed2007

The changes in coagulation profile and epidural catheter safety for living liver donors: a report on 6 years of our experience.

The use of epidural catheters has been a subject of active debate in living liver donors because of the possible postoperative coagulation derangement and the subsequent risk of epidural hematoma. The aim of this study was to evaluate the safety of epidural catheters in relation to the changes in coagulation profile based on a review of previously published literature and the results of our 360 donors. In both the literature and in our cases, platelet count, prothrombin time (PT), and activated partial thromboplastin time (aPTT) in cases of heparin administration showed significant changes (P < 0.05), especially after right lobectomy. Platelet count reached its nadir on postoperative day (POD) 2-3, while PT and aPTT reached their peaks on POD 1-2 and at the end of the operation, respectively. In our donors, the ranges of platelet count, PT, and aPTT for the first 3 PODs were 54-359 x10/microL, 0.99-2.38 international normalized ratio (INR), and 25.9-300 seconds, respectively, and of note, 5 donors (1.4%) had a platelet count of <80 x 10/microL and 9 donors (2.5%) had a PT of >2.0 INR. Epidural catheterizations were performed in 242 donors, and the catheters were removed on POD 3-4 in 177 donors (73.1%). Mean (range) of platelet count, PT, and aPTT on the day of catheter removal were 168.4 +/- 42.9 (82-307) x 10/microL, 1.33 +/- 0.18 (0.99-1.93) INR, and 40.9 +/- 4.8 (32.0-70.6) seconds, respectively. No epidural hematoma was observed in this study. In conclusion, the discreet use of epidural catheters in live liver donors, in spite of postoperative coagulation derangements, appears to be safe regardless of the type of hepatectomy performed.

Adult↗

PubMed2006

The hemostatic profiles of patients with Type O and non-O blood after acute normovolemic hemodilution with 6% hydroxyethyl starch (130/0.4).

BACKGROUND: Individuals with Type O blood have been reported to have a tendency toward reduced Factor VIII and von Willebrand Factor (vWF) levels. If this is true, patients with Type O blood might be vulnerable to coagulopathy during acute normovolemic hemodilution using hydroxyethyl starch (HES), both from hemodilution as well as HES-related coagulopathy. METHODS: Thirty non-O and 15 type O ASA 1 or 2 patients scheduled for spinal surgery involving more than two spinal levels were enrolled for the study. After anesthesia induction, 30% of the estimated blood volume was removed, and the volume was simultaneously replaced with 6% HES (130/0.4). Coagulation profiles were measured before (T0) and 30 min after acute normovolemic hemodilution (T30). RESULTS: Factor VIII activity, vWF antigen levels (vWF:ag), and vWF ristocetin cofactor activity (vWF:RCof) were lower in the O group than in the non-O group before and after acute normovolemic hemodilution, and decreased below the normal range in the O group after acute normovolemic hemodilution. The decrease was beyond that expected from hemodilution alone. Maximum amplitude and coagulation index of the thromboelastogram decreased below the normal range in the O group after acute normovolemic hemodilution. The decrease in vWF:ag was related to the degree of blood loss, and was greater in patients in the O group. CONCLUSIONS: Patients with Type O blood may have increased coagulation compromise, and greater dilution of Factor VIII activity, vWF:ag, and vWF:RCof after acute normovolemic hemodilution with HES.

ABO Blood-Group System↗

PubMed2006

Arteriovenous malformations of the body and extremities: analysis of therapeutic outcomes and approaches according to a modified angiographic classification.

PURPOSE: To propose a modified angiographic classification for peripheral arteriovenous malformations (AVMs) and to determine its value for assessing therapeutic outcomes and approaches to ethanol embolization of AVMs in the body and extremities. METHODS: AVMs of the trunk and extremities were categorized according to the angiographic morphology of the nidus: type I (arteriovenous fistulae), type II (arteriolovenous fistulae), type IIIa (arteriolovenulous fistulae with non-dilated fistula), and type IIIb (arteriolovenulous fistulae with dilated fistula). Sixty-six patients (41 women; mean age 28.3 years, range 5-53) with inoperable AVMs in the body and extremities who underwent staged ethanol embolizations were retrospectively analyzed. Therapeutic outcomes and approaches were evaluated according the above classification system. RESULTS: The 66 AVMs were composed of 30 (45%) type IIIb, 13 (20%) type II, 12 (18%) mixed types IIIa and IIIb, 9 (14%) mixed types II and IIIb, and 2 (3%) type IIIa. Ethanol embolization was most effective for type II (100%), and more effective for type IIIb (83%) than for type IIIa or mixed types (< or = 50%). Despite the use of the transarterial approach, direct puncture and transvenous approaches were more relevant for treating type II AVMs. Only the transarterial approach was used for treating type IIIa; both direct puncture and transarterial approaches were used for treating the other types. CONCLUSION: The described angiographic classification provides considerable information concerning the characteristics of AVMs in the body and extremities, the optimal therapeutic approach, and the likely therapeutic outcome.

Adolescent↗

PubMed2005

Thoracic epidural anesthesia does not improve the incidence of arrhythmias after transthoracic esophagectomy.

OBJECTIVE: The incidence of arrhythmias related to an esophagectomy is high, and its clinical significance has been well accepted. Thoracic epidural anesthesia (TEA) can modulate the sympathetic tone and neuroendocrine responses associated with major operation. This study was aimed to evaluate the effects of TEA on the incidence of arrhythmias in transthoracic esophagectomy patients. METHODS: The records of 185 patients who underwent the Ivor-Lewis operation between 2001 and 2004 by the same operator were reviewed. The patients were divided into three groups. Group 1 (n = 58) received post-operative intravenous patient-controlled analgesia without TEA. Group 2 (n = 55) received postoperative epidural patient-controlled analgesia using local anesthetics. The patients of group 3 (n = 72) were anesthetized intra-operatively by the combination technique of thoracic epidural bupivacaine and inhalation agents, and post-operative pain control was done in the same way with group 2. RESULTS: Arrhythmias occurred 29.3, 50 and 29.2% in groups 1, 2 and 3, respectively. There were no statistical differences in the incidences of arrhythmias among the three groups. CONCLUSIONS: This result shows that TEA was not beneficial to reduce the incidence of arrhythmias in the transthoracic esophagectomy patients.

Aged↗

PubMed2005

Hypobaric spinal anesthesia with 0.2% tetracaine for total joint hip arthroplasy.

PURPOSE: Hypobaric local anesthetics for total hip replacement (THR) have potential advantages related to body position and differential block. However, the dose requirements of hypobaric local anesthetics for THR have not been clearly established. Therefore, we undertook a dose-response study of hypobaric tetracaine for THR. METHODS: In a randomized, controlled, and double-blinded manner, three groups of 20 patients each undergoing THR received spinal anesthesia using either 10, 12, or 14 mg of 0.2% hypobaric tetracaine in a lateral decubitus position, with the operated side up. Adequate anesthesia was defined as: 1) upper sensory block between T10 and T4; 2) motor block of modified Bromage scale 2 or 3; and 3) time to sensory remission to the L2 level of more than three hours. RESULTS: The number of patients who achieved adequate sensory and motor block levels was similar amongst the three groups. However, all patients who received 14 mg had a sensory remission time to L2 of more than three hours while only 30% of the patients in the 12 mg group and no patient in the 10 mg group had the same remission time. A significant differential block was observed between the non-dependent and the dependent sides, but the degree of differential block was not different between the groups. CONCLUSION: 10 to 14 mg of 0.2% hypobaric tetracaine achieved similar and adequate block levels, but different regression times. To ensure complete sensory block duration for THR, we recommend using 14 mg of 0.2% hypobaric tetracaine.

Adult↗

PubMed2005

A korean predictive model for postoperative nausea and vomiting.

Postoperative nausea and vomiting (PONV) is one of the most common and distressing complications after surgery. An identification of risk factors associated with PONV would make it easier to select specific patients for effective antiemetic therapy. We designed a case-controlled study to identify the risk factors for PONV in 5,272 surgical patients. At postoperative 2 and 24 hr, patients were visited and interviewed on the presence and severity of PONV. Thirty nine percent of patients experienced one or more episodes of nausea or vomiting. Five risk factors were highly predictive of PONV: 1) female, 2) history of previous PONV or motion sickness, 3) duration of anesthesia more than 1 hour, 4) non-smoking status, and 5) use of opioid in the form of patient controlled analgesia (PCA), in the order of relevance. The formula to calculate the probability of PONV using the multiple regression analysis was as follows: P (probability of PONV)=1/1+e(-Z), Z=-1.885+0.894 (gender)+0.661 (history)+0.584 (duration of anesthesia)+0.196 (smoking status)+0.186 (use of PCA-based opioid) where gender: female=1, male=0; history of previous PONV or motion sickness: yes=1, no=0; duration of anesthesia:more than 1 hr=1, less than or 1 hr=0; smoking status: no=1, yes=0; use of PCA-based opioid: yes=1, no=0.

Anesthesia↗

PubMedDate not supplied

Relationship between the bevel of the Tuohy needle and catheter direction in thoracic epidural anesthesia.

BACKGROUND AND OBJECTIVES: Directing an epidural catheter cephalad or caudad is usually attempted by orienting the beveled edge of the epidural needle. However, there have been few studies about the relationship between the direction of the bevel of epidural needle and the resulting position of the catheter. We studied this relationship in thoracic epidural catheter placement. Catheter position was confirmed by using picture archiving communication systems (PACS). PACS is a workstation that stores radiologic images, which can be manipulated to visualize the catheters. METHODS: One hundred six patients receiving thoracic epidural anesthesia were enrolled. The cephalad and caudad groups (each with 53 patients) received epidural anesthesia at the T6-7 interspace with either a cephalad- or caudal-directed Tuohy needle. The final position of all of the catheters was confirmed by PACS. RESULTS: In the cephalad group, 63.5% of the catheters were confirmed to travel in a cephalad direction. In the caudad group, 22.0% of the catheters advanced in a caudad direction. Curling of the catheters occurred in 17.6%. PACS showed the catheter positions with satisfactory quality. CONCLUSIONS: The correlation between bevel direction and location of the thoracic epidural catheter was relatively low. Practices such as threading an epidural catheter by manipulation of the Tuohy needle for the control of pain at a distant site may not yield good results.

Adult↗