Ramalinga Raju A.V.S1, S.V. Ravikant2
Dexmedetomidine is a centrally acting active selective α2A agonist, which is used as an adjunct to anaesthesia, analgesia and sedation are produced with little respiratory depression, amnesia or anaesthesia. Ropivacaine is a newer congener of bupivacaine, but less cardiotoxic. It blocks A?? and C fibre more completely than A?? fibres. A greater degree of separation of motor and sensory block occurs with this. Present study is designed to compare the effect of dexmedetomidine intravenous infusion with ropivacaine versus intrathecal dexmedetomidine with ropivacaine on various parameters like sensory and motor block and quality of analgesia.
MATERIALS AND METHODS
Total 120 patients were included in this study and were divided into two groups. Each group is having 60 patients. Group A were given 20 mL of 0.75% ropivacaine hydrochloride, intravenous infusion of 1 mcg/kg given over 10 min. followed by maintenance dose of 0.25 mcg/kg/hrs. of infusion of dexmedetomidine, while group B were given 20 mL of 0.75% ropivacaine with 16 mcg dexmedetomidine. Various parameters like sensory and motor block and quality of analgesia was measured in both the group.
Time required to reach T10 sensory level was having mean value 4.2 min. group A, but in group B, it was 3.6 min., this difference among the two group was statistically significant (P<0.05). Peak sensory block achieved in group A is T5 and in group B was T4. After administration of drug, the mean time taken to reach peak sensory level in group A was 11.2 min. and in group B it was 10.26, which was comparable to each other with P value <0.05. The onset of motor block as per Bromage scale was 5.6 min. group A and 4.2 min. in group B and the total duration of motor block was 360 min. in group B that is higher than group A that is 296 min. for 1st dose of analgesic was 8 hrs. in group A, in group B, it was early that is 6 hours.
Infusion of dexmedetomidine or with 16 mcg dexmedetomidine intrathecal produced a significant prolongation in the durations of motor and sensory block, but that administered intrathecally had more significant prolonging effect than that administered intravenously. But, there was significant difference in effect on haemodynamic profile.
Intravenous Infusion, Intrathecal, Dexmedetomidine.