ropivacain baRicity

Spinal anesthesia is one of the most widely used techniques in modern anesthesia practice. It involves the injection of local anesthetic drugs into the cerebrospinal fluid (CSF) within the subarachnoid space. The choice of drug, its concentration, and baricity play a crucial role in determining the characteristics of the spinal block and has evolved over the years with continuous advancements in drug formulations and administration methods. Spinal anesthesia with hypobaric drugs represents a valuable technique in the armamentarium of anesthesiologists, offering distinct advantages in terms of targeted action, reduced systemic toxicity, and enhanced hemodynamic stability...

BACKGROUND: Pain during cesarean delivery is one of the more common reasons for a successful medicolegal claim. However, creating an extensive block area can result in hypotension, so determining the precise dose of local anesthetic is critical. OBJECTIVES: Investigate effects of parturient height on the median effective dose (ED50) of intrathecally-administered ropivacaine. DESIGN: Prospective cross-sectional analytic study. SETTING: Anesthesiology department in a provinicial hospital in China...

BACKGROUND: Although local anesthetics (LAs) are hyperbaric at room temperature, density drops within minutes after administration into the subarachnoid space. LAs become hypobaric and therefore may cranially ascend during spinal anesthesia in an uncontrolled manner. The authors hypothesized that temperature and density of LA solutions have a nonlinear relation that may be described by a polynomial equation, and that conversion of this equation may provide the temperature at which individual LAs are isobaric...

BACKGROUND: Spread of intrathecal local anaesthetics is determined principally by baricity and position of the patient. Hypobaric solutions of bupivacaine are characterized by an unpredictable spread of sensory block whereas addition of dextrose 80 g ml(-1) provides a predictable spread but to high thoracic levels. In contrast, dextrose concentrations between 8 and 30 g ml(-1) have shown reliable and consistent spread for surgery. Hence, the aim of this study was to determine the density of bupivacaine, levobupivacaine, and ropivacaine with and without dextrose at both 23 and 37 degrees C before embarking on clinical studies...

BACKGROUND: Transient neurologic symptoms (TNS) after spinal anesthesia (SPA) is defined as back pain with radiation or dysesthesia in the buttocks, thighs, hips and calves, occurring within 24 h after recovery from otherwise uneventful SPA. The symptoms last for about 1-3 days but neurophysiologic evaluation does not show pathologic findings. The type and the preparation of the local anesthetic drug (baricity, concentration, additives or preservatives) are most often discussed as the underlying cause of TNS...