Chul Joong Lee

Comparison between high and low molecular weight hyaluronates in knee osteoarthritis patients: open-label, randomized, multicentre clinical trial.

Efficacy and safety of high and low molecular weight hyaluronates in knee osteoarthritis patients were compared in a randomized, open-label trial. Patients in the high molecular weight hyaluronate group were treated once weekly for 3 weeks and in the low molecular weight group once weekly for 5 weeks. We evaluated weight-bearing pain, degree of flexion, swelling and knee tenderness; frequency and amount of rescue medication; patient and investigator global assessment of pain, and safety over 12 weeks after final injection of study medication. Significant improvements in pain and WOMAC-Likert scores were observed in both groups, but not between groups. Knee joint pain improvement was noted in both groups by patients and investigators during follow-up. Close correlation was observed between patient-and investigator-reported data. There was no significant difference in side-effects between the groups. In conclusion, the efficacy and safety of high and low molecular weight hyaluronate are similar.

The influence of neck flexion and extension on the distribution of contrast medium in the high thoracic epidural space.

BACKGROUND:For safe and effective thoracic epidural analgesia (TEA), it is important to control the level of TEA and to identify factors that influence its spread. In this study, we observed the distribution of contrast injected into the high thoracic epidural space during neck flexion and extension. METHODS:An epidural catheter was inserted into the epidural space until its tip was located at the T1–2 intervertebral level. Patients were randomly allocated to three groups (extension, flexion, and neutral groups), and were injected with 5 mL of contrast when the neck was extended, flexed, or in the neutral position. Extent of contrast spread was determined by counting the number of vertebral body units (VBUs) through lateral epidurography. RESULTS:Forty-two patients were equally allocated to the three groups. Radiographic spreads in the cephalad direction (median) was 1.0, 5.5, and 1.5 VBUs in the extension, flexion, and neutral groups, and spread was greater in the flexion than in the other two groups (P < 0.001). Median radiographic caudal spread was 10.0, 10.0, and 7.0 VBUs in the extension, flexion, and neutral groups, respectively, which was not significantly different among groups (P = 0.145). CONCLUSIONS:Cranial spread of contrast in the high thoracic epidural space is limited. However, neck flexion increases cranial spread. These results suggest that when TEA is high, the tip of the epidural catheter should be located at the upper part of the level to be blocked and that neck flexion may cause an unwanted cervical block.

The neurological safety of epidural gabapentin in rats: a light microscopic examination.

Gabapentin acts primarily on the central nervous system. Therefore, we hypothesized that the direct epidural administration of gabapentin could have various advantages over its oral administration with respect to required dose, side effects, and efficacy. However, before administering gabapentin into the epidural space in a clinical setting, its neurotoxicity must be examined in animals. Thus, we evaluated neurotoxicity of epidural gabapentin by observing behavioral and sensory-motor changes, and by histopathological examinations of spinal cords and dorsal root ganglia in the rat. Twenty-seven rats were randomly divided into 3 groups, which were administered 0.3 mL (30 mg) of epidural gabapentin (group G, n = 9) and the same volume of epidural alcohol (group A, n = 9) or normal saline (group N, n = 9). No rats in groups G and N showed sensory-motor dysfunction, behavioral change, or histopathological abnormalities over a 3-wk observation period, whereas all rats in group A showed abnormalities. We conclude that the direct epidural injection of gabapentin in rats did not show any neurotoxic evidence in terms of sensory-motor functions and behavior, or by a microscopic histopathological evaluation. This study represents a first promising step toward the trial of epidural gabapentin in a clinical setting.