Prolongation of Spinal Anesthesia with T-Cain by Epinephrine and Clonidine / 대한마취과학회지

Vasoconstrictors such as epinephrine or phenylephrine have been used as an adjunct to local anesthetics to prolong the duration of spinal anesthesia. Recently, clonidine, an areceptor agonist, has been proved to have analgesic effect and to prolong epidural and spinal anesthesia. We used 0.3mg of epinephrine, 75 ug and 150 ug of clonidine in spinal anesthesia with 12 mg of T-Cain respectively and compared hemodynamic and analgesic effects of each drug. Heart rate and blood pressure were checked before, during and after anesthesia. Sensory level was checked by pin-prick method and motor blockade was measured by Bromages scale. The results were as follows. 1) Heart rate changed little in the epinephrine group and decreased significantly in all other groups.2) Systolic blood pressure decreased significantly in all groups except the epinephrine group. Both 75 ug and 150 ug of clonidine caused a significant fall in diastolic pressure. 3) The onset time for sensory and motor blockade varied little among all groups. 4) Sensory blockade was significantly higher in the 150 ug of clonidine group than the control group. Time to achieve the maximum level of sensory blockade was significantly faster in control group than 150 ug of clonidine group. 5) The duration of sensory and motor blockade was significantly prolonged in epinephrine and clonidine group than control group. The results indicate that clonidine, when used as an adjunct to T-Cain spinal anesthesia, is as effective as epinephrine in prolongation of motor and sensory blockade.

The Effect of Discontinuation of N2O on the Middle Ear Pressure during General Endotracheal Anesthesia / 대한마취과학회지

N2O can diffuse in and/or out the middle ear cavities and it may alter the middle ear pres-sure. This study was performed to investigate the effect of N2O discontinuation on the changes in middle ear pressure during general endotracheal anesthesia. We measured middle ear pres-sures and end-tidal NO concentrations at preanesthesia, immediately after N2O discontinuation and then at every five minutes for 60 minutes under either halothane or enflurane an- esthesia in two groups(group 1=50% administration of N2O in O2; group 2=60% administration of N2O in O2). The middle ear pressures after N2O discontinuation decreased slowly but they did not returned to the preanesthetic value in both groups. The end-tidal N2O concentrations decreased rapidly until five minutes and then they decresed slowly to the zero leve1 until 30 minutes after N2O discontinuation in both groups. The expected time of the middle ear pres-sure of preanesthesia value was 89.4 minutes in group 1 and 80.9 minutes in group 2 respectively. The middle ear pressure do not return to the level of preanesthesia at 60 minutes after N2O discontinuation while the end-tidal N2O concentration decrease to the zero level via 30 minutes after its discontinuation. Thus it is recommended that N2O administration should be discontinued at least 30 minutes before an application of tympanic membrane patch on the ear drum and N2O is carefully administered in patients with middle ear and/or upper airway disesses.

The Effect of Discontinuation of N2O on the Middle Ear Pressure during General Endotracheal Anesthesia / 대한마취과학회지

N2O can diffuse in and/or out the middle ear cavities and it may alter the middle ear pres-sure. This study was performed to investigate the effect of N2O discontinuation on the changes in middle ear pressure during general endotracheal anesthesia. We measured middle ear pres-sures and end-tidal NO concentrations at preanesthesia, immediately after N2O discontinuation and then at every five minutes for 60 minutes under either halothane or enflurane an- esthesia in two groups(group 1=50% administration of N2O in O2; group 2=60% administration of N2O in O2). The middle ear pressures after N2O discontinuation decreased slowly but they did not returned to the preanesthetic value in both groups. The end-tidal N2O concentrations decreased rapidly until five minutes and then they decresed slowly to the zero leve1 until 30 minutes after N2O discontinuation in both groups. The expected time of the middle ear pres-sure of preanesthesia value was 89.4 minutes in group 1 and 80.9 minutes in group 2 respectively. The middle ear pressure do not return to the level of preanesthesia at 60 minutes after N2O discontinuation while the end-tidal N2O concentration decrease to the zero level via 30 minutes after its discontinuation. Thus it is recommended that N2O administration should be discontinued at least 30 minutes before an application of tympanic membrane patch on the ear drum and N2O is carefully administered in patients with middle ear and/or upper airway disesses.