Effect of different intrathecal morphine doses in low dilute dose bupivacaine for postoperative analgesia in anal surgery

ABSTRACT

Postoperative pain for anal surgery is a concern. Intrathecal morphine is effective and simple method for postoperative analgesia. The aim of this study is to compare the efficacy of 50 ug intrathecal morphine in low dilute bupivacaine 0.125% to 100 ug morphine in low dilute bupivacaine 0.125% and to compare the advantage and disadvantage in each group. Sixty patients of ASA grade I and II scheduled for anal surgery were randomly allocated to receive saddle block in setting position either lml of 0.25% hyperbaric bupivacaine with 1ml saline 0.9% [total volume 2ml to give concentration of 0.125%] [Group I n=20] or 1ml of hyperbaric bupivacaine 0.25% with 1ml of morphine 50 micro g [group II n=20] or 1ml hyperbaric bupivacaine 0.25% with 1ml of morphine 100 ug [group III n=20]. The duration of analgesia in the groups I, H, III were 2.8 +/- 0.55 hr, 6.4 +/- 0.8 hr and 11.2 +/- 1.2 hr respectively which was highly significant. Postoperative nausea and vomiting occurred at overall highly significant incidence during the first 24 hours, in group II, III, while there was no nausea and vomiting in group I. Urinary retention was also significant between group I, II and III with mean 3.95, 6.82 and 9.12 hours, in group II eight patients need catheter while in group Ill fourteen patients need catheter. As regard pruntus no patients in group I, while in group II one patients complaining of sever pruritus, in group Ill five patients complaining of sever pruritus and need treatment. A transient respirator depression with respiratory rate<8 pen minute and SPO2<90% occurred in one patients only in group III. No homodynamic changes