Biomedical subjects

D Holst

Publications and source records attributed to D Holst.

93 records · Page 6Linked to original sources

PubMedDate not supplied

Intrathecal local anesthetic distribution with the new spinocath catheter.

BACKGROUND AND OBJECTIVES: Microcatheters have been linked in some cases to the development of cauda equina syndrome, which may be further traced to the maldistribution of the local anesthetic. A long injection time via the microcatheters contributes to the inadequate mixing. With the new Spinocath catheter, considerably shorter injection times can be achieved due to larger internal size. This study examined whether this leads to more homogeneous intrathecal distribution without causing greater trauma to the dura. METHODS: In an in vitro model of the spinal canal, the distribution of hyperbaric and isobaric 0.5% bupivacaine (2.5 mL) as well as 5% lidocaine (2.5 mL) was examined after injection via the 28-gauge CoSpan catheter (Kendall, Healthcare, Mansfield, MA), the 22-gauge Spinocath catheter (Braun, Melsungen, Germany), and a 29-gauge Quincke needle (Becton Dickinson, Rutherford, NJ). The local anesthetic concentration in the vertebral interspaces T12-L1 to L5-S1 was measured via gas chromatography 3 and 10 minutes after injection. In addition, the morphologic puncture characteristics of human dura were examined with the halftone electron microscope, after puncture with the catheters and needle. RESULTS: After injection through the 28-gauge CoSpan catheter, caudal segments of the spinal canal showed peak concentrations up to a maximum of 1,147 microg/mL bupivacaine or 8.5 mg/mL lidocaine with hyperbaric solutions, which did not decrease over the 10 minutes of measurement. After injection through the Spinocath catheter, there was a homogeneous distribution with data peaks of approximately 350 microg/mL bupivacaine or 4.2 mg/mL lidocaine similar to the data found after injection through the spinal needle. CONCLUSIONS: The new Spinocath catheter allows a better mixing of the local anesthetic with the cerebrospinal fluid. Because of significantly shortened injection times, hyperbaric solutions also show a more homogeneous distribution. Although the Spinocath catheter has a larger inner diameter than the other microcatheters, it appeared to cause less trauma to the dura.

Anesthesia, Spinal↗

PubMedDate not supplied

Causal patterns of dental health in populations. An empirical approach.

In the present investigation we aimed to analyse causally the pattern of determinants leading to the maintenance of functional teeth in adults. Clinical and self-reported information was used. The hypothesis was that socio-economic conditions operate through psychosocial circumstances that influence lifestyle, and are thus related to oral hygiene and levels of remaining teeth. Testing of the patterns for adults residing in high- and low-fluoride areas did not reveal any principal differences in dental health, therefore further testing was combined for both fluoride areas. Further analysis also indicated that testing should be performed separately for each gender. Social structure and dental health-related lifestyle were important in an overall pattern of maintaining functional teeth, but general lifestyle and psychosocial conditions were not found to be part of the pattern influencing dental health. Gender-specific patterns were revealed. New hypotheses may be suggested for further research with regard to studying patterns of dental health in Lithuanian adults.

Adult↗

PubMedDate not supplied

Continuous spinal anesthesia: mechanical and technical problems of catheter placement.

BACKGROUND AND OBJECTIVE: Although continuous spinal anesthesia with microcatheters has a number of advantages, there are also some drawbacks: technical problems in advancing the catheter, the possibility of traumatizing neural structures, the development of cauda equina syndrome, and maldistribution of the local anesthetic. METHODS: Spinaloscopy was performed with a 2-mm-diameter endoscope in fresh cadavers to visualize the fate of the catheters, as well as the distribution of the local anesthetic administered through these fine-bore catheters. Midline and paramedian approach achieved an easy insertion of the 28-gauge catheter as long as the 22-gauge needle was not advanced too far into the subarachnoid space, thereby making it impossible for the catheter to bend at the anterior wall of the dura mater. RESULTS: Injection of methylene blue-colored hyperbaric local anesthetic through the catheter revealed an inhomogenous distribution with pooling in the caudal segments. After the catheter tip leaves the needle, the catheter should be advanced only 2-3 cm to avoid coiling, possible damage of the nerve roots, or malpositioning in preformed pouches. CONCLUSION: To take advantage of continuous spinal anesthesia, a meticulous technique is required.

Anesthesia, Spinal↗