M Marucci1, C Diele, F Bruno, T Fiore. 1. Operative Unit of Anesthesia and Resuscitation II, Polyclinic Hospital, Bari, Italy. massimo.marucci@tin.it
Abstract
AIM: Subjects in spinal anaesthesia have been reported to show a decrease in the level of alertness, even when they have not received any sedative drugs. THE AIM: of this study is to verify, in caesarean delivery if the bupivacaine subarachnoid anaesthesia, with or without intrathecal fentanyl dose, produces a sedative effect, to define the entity and to identify the mechanism that most likely causes it. METHODS: The clinical investigation is divided into Part I (non-randomized trial) and Part II (randomized trial) and is set in the University hospital's delivery-unit. Part I: 45 pregnant women were recruited and enrolled in 3 groups: women having natural delivery (n=15), women receiving caesarean delivery with subarachnoid anaesthesia (n=15) and with general anaesthesia (n=15). Self-rating depression scale (SDS), self-rating anxiety scale (SAS), state anxiety inventory (SAI) and trait anxiety inventory (TAI) psychometric tests were patient-completed for pre-delivery anxiety evaluation. Part II: 23 pregnant women undergoing caesarean delivery were single-blind randomized to receive subarachnoid anaesthesia with single 12.75 mg 0.5% hyperbaric bupivacaine (n=10) or with 12.75 microg 0.5% hyperbaric bupivacaine and 15 mg fentanyl (n=13). Bispectral index (BIS), observer's assessment of alertness/sedation (OAA/S) scale, self-sedation visual analogic scale (VAS) and mean arterial pressure (MAP) were perioperatively monitored. RESULTS: Part I: it was found, using SAI, a higher level of state anxiety in the pregnant women undergoing caesarean delivery than those having natural delivery (p<0.05). Part II: pregnant women receivingsubarachnoid anaesthesia for caesarean delivery had a decrease of the level of alertness from 10 to 70 min after the execution of lumbar puncture (p<0.05), with a sedative peak from 35 to 45 min (p<0.01), as measured by OAA/S scale and self-sedation VAS but not by BIS. Women who received bupivacaine-fentanyl spinal anaesthesia had a more consistent sedative effect from 35 to 70 min (p<0.05). CONCLUSIONS:Pregnant women undergoing caesarean delivery had a more elevated level of state anxiety, assessed by SAI, as seen in Part I. Subarachnoid anaesthesia in caesarean delivery is associated with a reduction of alertness level. A double mechanism might cause a clinically valuable sedative effect, observed by OAA/S scale and self-sedation VAS: decrease of the afferent spinal inputs and an anxiolytic psychophysiologic effect, induced by good outcome of the birth and mother-baby contact. Intrathecal bupivacaine-fentanyl dose produces a larger alertness decrease than single bupivacaine, because the anaesthetic block density increases. BIS was not a sensitive measure to detect the light sedation occurring in Part II of this study.
RCT Entities:
AIM: Subjects in spinal anaesthesia have been reported to show a decrease in the level of alertness, even when they have not received any sedative drugs. THE AIM: of this study is to verify, in caesarean delivery if the bupivacainesubarachnoid anaesthesia, with or without intrathecal fentanyl dose, produces a sedative effect, to define the entity and to identify the mechanism that most likely causes it. METHODS: The clinical investigation is divided into Part I (non-randomized trial) and Part II (randomized trial) and is set in the University hospital's delivery-unit. Part I: 45 pregnant women were recruited and enrolled in 3 groups: women having natural delivery (n=15), women receiving caesarean delivery with subarachnoid anaesthesia (n=15) and with general anaesthesia (n=15). Self-rating depression scale (SDS), self-rating anxiety scale (SAS), state anxiety inventory (SAI) and trait anxiety inventory (TAI) psychometric tests were patient-completed for pre-delivery anxiety evaluation. Part II: 23 pregnant women undergoing caesarean delivery were single-blind randomized to receive subarachnoid anaesthesia with single 12.75 mg 0.5% hyperbaric bupivacaine (n=10) or with 12.75 microg 0.5% hyperbaric bupivacaine and 15 mg fentanyl (n=13). Bispectral index (BIS), observer's assessment of alertness/sedation (OAA/S) scale, self-sedation visual analogic scale (VAS) and mean arterial pressure (MAP) were perioperatively monitored. RESULTS: Part I: it was found, using SAI, a higher level of state anxiety in the pregnant women undergoing caesarean delivery than those having natural delivery (p<0.05). Part II: pregnant women receiving subarachnoid anaesthesia for caesarean delivery had a decrease of the level of alertness from 10 to 70 min after the execution of lumbar puncture (p<0.05), with a sedative peak from 35 to 45 min (p<0.01), as measured by OAA/S scale and self-sedation VAS but not by BIS. Women who received bupivacaine-fentanyl spinal anaesthesia had a more consistent sedative effect from 35 to 70 min (p<0.05). CONCLUSIONS: Pregnant women undergoing caesarean delivery had a more elevated level of state anxiety, assessed by SAI, as seen in Part I. Subarachnoid anaesthesia in caesarean delivery is associated with a reduction of alertness level. A double mechanism might cause a clinically valuable sedative effect, observed by OAA/S scale and self-sedation VAS: decrease of the afferent spinal inputs and an anxiolytic psychophysiologic effect, induced by good outcome of the birth and mother-baby contact. Intrathecal bupivacaine-fentanyl dose produces a larger alertness decrease than single bupivacaine, because the anaesthetic block density increases. BIS was not a sensitive measure to detect the light sedation occurring in Part II of this study.