The effect of posture and baricity on the spread of intrathecal bupivacaine for elective cesarean delivery.

Posture and baricity during induction of spinal anesthesia with intrathecal drugs are believed to be important in determining spread within the cerebrospinal fluid. In this double-blind prospective study, 150 patients undergoing elective cesarean delivery were randomized to receive a hyperbaric, isobaric, or hypobaric intrathecal solution of 10 mg bupivacaine during spinal anesthesia induced in either the sitting or right lateral position. After an intrathecal injection using a combined-spinal technique patients were placed in the supine wedged position.

Predicting the density of bupivacaine and bupivacaine-opioid combinations.

Manipulating the density of local anesthetic solutions by using a simple formula may be clinically useful in producing optimal density solutions for spinal anesthesia under a variety of clinical conditions.