BACKGROUND: Differences in epidural pressure (EP) may influence the spread of blockade in thoracic epidural anesthesia. We evaluated if EP and the incidence of subatmospheric EP differ between the mid- and low-thoracic epidural space. METHODS: Patients received an epidural catheter at the T3-5 (MID group, n = 20) or T7-10 (LOW group, n = 20) intervertebral space, respectively. The epidural space was identified using a Tuohy needle connected to a pressure transducer, after which EP was measured. RESULTS: The epidural space could not be identified in three patients who were excluded from the study. EP data are presented as median value (interquartile range). Median EP was 1 mm Hg (-1 to 4.5) in the MID group, and 4 mm Hg (2-7.8) in the LOW group (P = 0.04). The incidence of an EP <or=0 mm Hg was 8 of 17 patients in the MID group and 2 of 20 patients in the LOW group (P = 0.02). CONCLUSIONS: We conclude that EP is lower, and the incidence of subatmospheric EP is higher in the mid-thoracic epidural space when compared with that in the low-thoracic epidural space. However, median EP was positive in both groups. It remains to be investigated whether this pressure gradient is sufficient to influence the spread of thoracic epidural blockade.
BACKGROUND: Differences in epidural pressure (EP) may influence the spread of blockade in thoracic epidural anesthesia. We evaluated if EP and the incidence of subatmospheric EP differ between the mid- and low-thoracic epidural space. METHODS:Patients received an epidural catheter at the T3-5 (MID group, n = 20) or T7-10 (LOW group, n = 20) intervertebral space, respectively. The epidural space was identified using a Tuohy needle connected to a pressure transducer, after which EP was measured. RESULTS: The epidural space could not be identified in three patients who were excluded from the study. EP data are presented as median value (interquartile range). Median EP was 1 mm Hg (-1 to 4.5) in the MID group, and 4 mm Hg (2-7.8) in the LOW group (P = 0.04). The incidence of an EP <or=0 mm Hg was 8 of 17 patients in the MID group and 2 of 20 patients in the LOW group (P = 0.02). CONCLUSIONS: We conclude that EP is lower, and the incidence of subatmospheric EP is higher in the mid-thoracic epidural space when compared with that in the low-thoracic epidural space. However, median EP was positive in both groups. It remains to be investigated whether this pressure gradient is sufficient to influence the spread of thoracic epidural blockade.
Authors: Pedro L Antibas; Paulo do Nascimento Junior; Leandro G Braz; João Vitor Pereira Doles; Norma S P Módolo; Regina El Dib Journal: Cochrane Database Syst Rev Date: 2014-07-18