Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Jul 2001
Randomized Controlled Trial Clinical TrialDoes alkalinization of 0.75% ropivacaine promote a lumbar peridural block of higher quality?
We did not find clinical studies of the alkalization of ropivacaine in the literature. The objectives of this study were: (1) to determine the quantity of sodium bicarbonate (NaHCO(3)), which alkalinizes 0.75% ropivacaine (with and without adrenaline); (2) to verify the physico-chemical alterations arising from this alkalization; and (3) to determine whether alkalinized ropivacaine produces a higher-quality epidural block measured via sensory-motor onset, block spread and anesthesia duration. ⋯ This study indicates that the quantity of NaHCO(3) needed to alkalize 10 mL of 0.75% ropivacaine at room temperature is 0.012 mEq. When the solution contains adrenaline 1:200,000 (mg.mL(-1)), up to 0.015 mEq of NaHCO(3) may be added. The alkalization of the 0.75% ropivacaine solution did not cause a reduction of sensory-motor onset, but did provide a significant increase in the duration of the epidural block with no significant differences between the solutions with and without adrenaline.
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Reg Anesth Pain Med · Jul 2001
Addition of clonidine increases duration and magnitude of vasodilative effect induced by sympathetic block with mepivacaine in dogs.
The aim of this study is to examine the duration and magnitude of vasodilative effect induced by sympathetic block with the addition of clonidine to mepivacaine. ⋯ The addition of clonidine increases both duration and magnitude of the vasodilative effect induced by sympathetic block over that caused by mepivacaine alone.
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Reg Anesth Pain Med · Jul 2001
The effect of distance from injection site to the brainstem using spinal sufentanil.
Intrathecal (IT) sufentanil is commonly used in parturients to provide rapid onset of labor analgesia without motor block. This practice, although widely used, has been associated with severe respiratory depression in some patients. The mechanism of this respiratory depression is unclear, however, rapid cephalad movement and interaction with parenteral opioids are 2 frequently cited explanations for this complication. Because this complication has occurred only in women with heights between 150 and 157 cm, we elected to study the effect of the distance from injection site to the cisterna magna (CM) on peak brainstem cerebrospinal fluid (CSF) concentrations. ⋯ Our results suggest that sufentanil migrates relatively large distances in the IT space. Injection site (distance from the brainstem) appears to be a prominent factor in determining brainstem concentrations and subsequent respiratory depression after spinal administration. Reg Anesth Pain Med 2001;26:306-309.