Biomedical subjects

Kwok F J Ng

Publications and source records attributed to Kwok F J Ng.

4 recordsLinked to original sources

PubMed2006

A comparison of postoperative cognitive function and pain relief with fentanyl or tramadol patient-controlled analgesia.

STUDY OBJECTIVE: The use of different opioids for patient-controlled analgesia (PCA) may affect postoperative cognitive function differently. Patient-controlled analgesia fentanyl has been shown to preserve cognitive function better than morphine. The effect of PCA tramadol on cognitive function is unknown. This study aims to compare postoperative cognitive function and analgesia of PCA fentanyl or tramadol. DESIGN: Prospective randomized double-blinded study. SETTING: Metropolitan teaching hospital. PATIENTS: 30 ASA physical status I, II, and III patients undergoing lower abdominal operations. INTERVENTIONS: Patients received standard general anesthesia for their operations. Postoperatively, patients received either fentanyl (group F, 10 mug bolus, n = 17) or tramadol (group T, 20 mg bolus, n = 13) for PCA. Group F patients also received fentanyl boluses and group T patients received tramadol boluses intraoperatively. MEASUREMENTS: Cognitive function was measured using Mini-Mental State Examination and Benton Visual Retention Test (BVRT) preoperatively and on days 1 and 2. Pain was measured by numerical rating scale. RESULTS: No differences were found in postoperative Mini-Mental State Examination or BVRT scores, but significantly fewer (29.4%; 95% confidence interval [CI], 13.3%-53.1%) group F patients were able to complete BVRT compared with group T patients (84.6%; 95% CI, 57.8%-95.7%; 95% CI of difference, 19.4%-74.8%) (P = 0.010) on day 1. In the first 24 hours, group F and group T patients had similar analgesia at rest, but group T patients had better analgesia during cough (mean Numeric Rating Scale, 7.6; 95% CI, 7.0-8.2 vs 6.0; 95% CI, 4.8-7.2, group F vs group T) (P = 0.018; 95% CI of difference, 0.4-2.8). No differences were found in frequency of side effects or patient satisfaction. CONCLUSIONS: Tramadol or fentanyl PCA has similar cognitive effects on days 1 and 2; however, patients receiving tramadol PCA are more motivated to undergo cognitively demanding tasks and have slightly better analgesia on postoperative day 1.

Analgesia, Patient-Controlled↗

PubMed2005

A prospective, randomized, double-blind, placebo-controlled study of the platelet and global hemostatic effects of Ganoderma lucidum (Ling-Zhi) in healthy volunteers.

UNLABELLED: Ganoderma lucidum is a Chinese herbal medicine popular with cancer patients. Previous in vitro studies suggested that Ganoderma lucidum might impair hemostasis. In this prospective, randomized double-blind study, healthy volunteers received orally Ganoderma lucidum capsules 1.5 g (n = 20) or placebo (n = 20) daily for 4 wk. We monitored subjects before drug administration and at 4 and 8 wk thereafter by routine coagulation screen, fibrinogen concentration, von Willebrand ristocetin cofactor activity, platelet function analyzer PFA-100, and thrombelastography. There were no significant between-group differences and all measurements remained within the normal range. Ganoderma lucidum ingestion over 4 wk was not associated with impairment of hemostasis. IMPLICATIONS: Ingestion of Ganoderma lucidum does not cause impairment of hemostatic function in healthy volunteers, despite earlier in vitro reports that it may cause platelet inhibition and may have other antithrombotic and fibrinolytic activity. The use of Ganoderma lucidum preoperatively is unlikely to increase the risk of surgical bleeding in otherwise healthy patients.

Adult↗

PubMed2004

Changes in thrombelastograph variables associated with aging.

Aging is associated with hypercoagulability. To assess thrombelastography (TEG) variables associated with aging, 132 adult patients of various ages undergoing orthopedic surgery for fracture repair had venous blood samples withdrawn for testing of recalcified TEG before the induction of anesthesia. Age was weakly correlated with all TEG variables: r time (R) (r = -0.45, P < 0.001; R = 19.5 - 0.09 x age), k time (K) (r = -0.49, P < 0.001; K = 6.5 - 0.04 x age), maximum amplitude (MA) (r = 0.25, P < 0.01; MA = 53.3 + 0.07 x age), and alpha (r = 0.52, P < 0.001; alpha = 52.8 + 0.2 x age). The correlation was stronger for men than for women. Only R was significantly correlated with age when the women were separately analyzed. Part of the correlation may be attributable to a concurrent decrease in hemoglobin with aging, but age remained an independent predictor of R, K, and alpha on forward stepwise linear multiple regression analysis. Aging was weakly associated with changes in TEG variables, which should be allowed for when interpreting TEG measurements in the elderly.

Adolescent↗

PubMed2002

Value of preoperative coagulation tests: reappraisal of major noncardiac surgery.

In a retrospective case-control review, we evaluated preoperative coagulation testing in patients undergoing major noncardiac operations to determine if routine testing benefits this group of patients. The platelet count (PC), prothrombin time (PT), and activated partial thromboplastin time (aPTT) in all patients undergoing major noncardiac surgery over a 22-month period were reviewed. The review was done both manually and by the computerized hospital information system. Major surgery was defined as procedures usually associated with significant bleeding. For each patient with abnormal results, another two control patients undergoing the same surgery and matched for age and gender were identified. Case and control patients were compared regarding a change in the management plan, use of blood products, blood loss, and bleeding complications by detailed chart review. A total of 828 patients undergoing nine different surgeries were reviewed. The incidence of abnormal PCs was 2.2% [95% confidence interval (CI) 1.2-3.2%] and that of abnormal PT/aPTTs was 2.1% (95% CI 1.1-3.1%). There were only two cases each of thrombocytopenia and prolonged PT/aPTT where the coagulation tests were not indicated clinically. Although (compared to controls) patients with abnormal tests had more changes in their anesthesia plan (36% vs. 2%, p < 0.001) and platelet or fresh frozen plasma transfusions (50% vs. 9%, p < 0.001), blood loss and the incidence of bleeding complications were not different. We conclude that the use of preoperative coagulation tests in patients undergoing major noncardiac surgery should still be guided by clinical assessment. The surgical procedure itself does not constitute an indication for testing.

Blood Loss, Surgical↗