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Biomedical subjects

R Stienstra

Publications and source records attributed to R Stienstra.

44 records · Page 3Linked to original sources
PubMedDate not supplied

The first years of a consultation bureau for homosexuality.

The COC's attempt to form a consultation bureau which would supply social aid to homosexuals is presented. The details and problems of forming such a group, including financial matters, type of aid to be supplied, and staffing, are discussed. In conclusion, the total reformation of the bureau in the 1980's is explained. The reformation reflects the change in social tolerance toward homosexuality in The Netherlands.

Counseling↗
PubMedDate not supplied

Speed of injection does not affect subarachnoid distribution of plain bupivacaine 0.5%.

Three milliliters of plain bupivacaine 0.5%, previously warmed to 37 degrees C, was injected into the subarachnoid space in two groups of 20 patients. In Group 1, speed of injection of the bupivacaine solution was as fast as possible (mean, 0.54 ml/second), whereas in Group 2 the bupivacaine solution was administered at a rate of 0.05 ml/second. Patients were kept sitting for 3 minutes after completion of the subarachnoid injection. All observations were made by an observer unaware of the speed of injection. There were no statistically significant differences in onset to maximal level of sensory block (17.2 minutes in Group 1 versus 19 minutes in Group 2) or complete motor block of the lower limbs (9 minutes in both groups). The difference in the maximal level of sensory block as determined by pinprick (T4.9 in Group 1 versus T3.4 in Group 2) was statistically significant; this difference may be explained by the fact that the plain solution of bupivacaine 0.5% at 37 degrees C is hypobaric and patients in Group 2 were in the sitting position for 1 minute longer when measured from the start of the subarachnoid injection. It is concluded that a tenfold difference in speed of injection does not significantly affect subarachnoid spread or onset of sensory and motor block with 0.5% bupivacaine.

Anesthesia, Spinal↗
PubMedDate not supplied

The influence of temperature and speed of injection on the distribution of a solution containing bupivacaine and methylene blue in a spinal canal model.

Three milliliters of a solution containing 4.81 mg bupivacaine base and 0.029 mg methylene blue per milliliter (BMB) was injected in the middle of a vertically mounted spinal canal model containing 0.9% NaCl at 37 degrees C. The BMB solution injected was either equilibrated to 37 degrees C (Exp. I) or to 22 degrees C (Exp. II). Each experiment was conducted eight times, four times with a high speed of injection (+/- 0.6 ml/sec) and four times with a slow speed of injection (0.05 ml/sec). The density of the BMB solution was determined at 37 degrees C and at 22 degrees C and found to be, respectively, slightly hypobaric and slightly hyperbaric relative to the 0.9% NaCl solution of 37 degrees C. Three minutes after completion of the injection, nine 1-ml samples were drawn simultaneously from the site of injection and from eight sampling sites situated equally above and below the site of injection at 5-cm intervals, which were subsequently analyzed for methylene blue concentrations. Injection of the BMB solution equilibrated to 37 degrees C resulted in a distribution directed mainly upward, whereas injection of the BMB solution equilibrated to 22 degrees C showed distribution in a mainly downward direction. Variation in methylene blue concentrations was large, and no definite differences based on different speeds of injection were observed. It is concluded that small differences in baricity result in largely different distribution patterns that could explain the variability in sensory levels of blockade when using an isobaric solution for spinal anesthesia.

Bupivacaine↗
PubMedDate not supplied

Effect of speed of injection on the maximum sensory level for spinal anesthesia using plain bupivacaine 0.5% at room temperature.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate if a ten-fold difference in speed of injection of a plain solution of bupivacaine 0.5% at room temperature into the subarachnoid space would result in a temperature-dependent change in baricity large enough to be reflected in a significant difference between the maximum levels of sensory blockade. METHODS: In this prospective study, 40 male patients were randomly assigned to one of two groups. Group 1 patients received 3 ml plain bupivacaine 0.5% (20-22 degrees C) with the speed of injection as fast as possible. Group 2 patients received 3 ml plain bupivacaine 0.5% (20-22 degrees C) at a rate of 0.05 ml/sec. Thirty minutes after subarachnoid injection the maximum level of sensory blockade was determined by pinprick in the anterior axillary line by a blinded observer. RESULTS: The mean maximum level of sensory blockade in patients of group 1 was T7.5 (median, T7; range, T3-12) and in group 2 patients T6.4 (median, 5.5; range, T3-11), the difference not being statistically significant (p > 0.05). CONCLUSIONS: There is no clinically relevant influence on the maximum level of sensory blockade when bupivacaine 0.5% at room temperature is injected with a ten-fold difference in speed.

Aged↗