Intrathecal opioids and respiratory depression: Is it myth in obstetrics?

The addition of opioids to bupivacaine for spinal anesthesia has been shown to improve quality of anesthesia by the action of fentanyl, and extend postoperative analgesia by the effect of morphine. Side effects, particularly respiratory depression, have prevented their widespread use. Studies are not consistent regarding the incidence of respiratory depression due to the variety of definitions of this complication and the doses of opioids used. Low dose regimens currently used do not produce further respiratory depression than parenteral opioids. The high levels of progesterone, a potent respiratory stimulant, makes safe the use of neuroaxial opioids in scenarios such as obstetrical anesthesia or analgesia, hence their use should not be overlooked.