Comparison of intrathecal isobaric bupivacaine-morphine and ropivacaine-morphine for CS delivery Department of Anaesthesiology and Intensive Care and Department of OB&GYN, Facultry of medicine,Selcuk University,Konya,Turkey. BJA 90(5):659-64(2003)

BACKGROUND Ropivacaine  A new long acting  Amide  A high pKa and low lipid solubility  Block sensory N.> motor N.  Less cardiotoxic than bupivacaine in vitro  Higher threshold for CNS toxicity than racemic bupivacaine

BACKGROUND In previous study  Intrathecal hyperbaric ropivacaine :- non OB Sx. Or labour analgesia combined with sufentanyl or fentanyl (Chung and colleagues)  A dose-response study with isobaric ropivacaine in C/S (Khaw and colleagues)

OBJECTIVES Prospective, double-blind, randomized study Compare the analgesia and spinal block characteristics of 0.5% isobaric ropivacaine+morphine and 0.5% isobaric bupivacaine+morphine in C/S

MATERIALS AND METHODS ??????? 50 ASA I or II + elective CS of single babies at term Exclusion :-cardiac disease, haematological dis., DM, eclampsia, bleeding or coagulopathy, fetal distress or known fetal anomalies Premed. :- sodium citrate 30 ml 30 min before Fluid loading :- 6% hydroxyethystarch 10 ml/kg

MATERIALS AND METHODS A computer-generated randomization table group RM ( n=25 ) and group BM ( n=25 ) RM (n=25 ) 0.5% isobaric R. 15 mg + MO 150 ug BM (n=25 ) 0.5% isobaric B. 15 mg + MO 150 ug Anaesthetist not involved the data The investigator were blinded

MATERIALS AND METHODS Monitors :- HR, MAP, SpO2, RR, IV MT;- LRS 10 ml/kg/hr during surgery Spinal anaesthesia  Sitting position  Quincke needle NO.25  L3-4 or L4-5  Study solution 3.7 ml administered 30 s(0.12 ml/sec)  Confirmed by aspiration and re-injection of ml CSF before and after  Turned to supine with left uterine displacement position

MATERIALS AND METHODS After the spinal block:- HR,RR,SpO2 and MAP q 1 min until delivery and then q 2 min. Hypotension = 20% of baseline MAP Rx. Hypotension with ephredine 5-10 mg and total ephredine were recorded Supplement O2 with facemask

MATERIALS AND METHODS Sensory block loss of pin-prick sens. (20 G hypodermic needle) at MCL q 5 min until reached T5 dermatome the q 10 min Motor block Bromage scale(0=no motor block,3=complete block of lower ext) q 1 min until complete block q 30 min The motor block when the sensory level reached T5 were recorded

MATERIALS AND METHODS The time from skin incision to delivery After delivery,umbilical blood gas APGAR scores at 1 and 5 min Side effect and sedation or GA Maternal sedation scores 48 hrs. After surgery :- prutitus,headache,backache,resp.distress,N/V The quality of anaesthesia (by anaesthetists),the quality of MR (by surgeon)

STATISTICAL ANALYSIS SD of time to recovery from motor block and time to regression of two segment wiht ropivacaine power analysis 30-min difference in mean duration of motor block or a 10- min difference in mean duration two segment regression between 2 groups two-side alpha of 5% and beta of 20% Group size of was necessary One-way and two-way ANOVA repeated measures

STATISTICAL ANALYSIS Unpaired and paired t -tests for quantitative X2 test for categorical data P < 0.05 was significant

RESULTS As table

Table 1. Patient charactersistics BM (n=25) RM ( n=25) Height (cm)160.5(5.7)160.6(6.0) Weight (kg) 77.4(10.2) 76.1(16.5) Age (years) 29.1(19-43) 29.4(21-38) No.of preg 2.4(1.7) 2.1(0.8) No.of CS 0.3(0.5) 0.6(0.6) GA 39.7(2.1) 38.4(1.3) Operation time 27.3(11.5) 19.0(13.3) Delivery time 3.5(1.9) 4.1(2.0)

Table 2 Characteristics of SPB and PO analgesia times BM(n=25)RM(n=25) p Sensory block ns Motor block -time to complete -complete at T5 -time to complete recovery 4.0(2.0) 24(96) 220.0(32.4) 5.9(3.3) 22(88) 200.2(34.9) <0.05 ns <0.05 Sympathetic block -ephredine require -ephredine dose (8.6) (5.2) ns <0.05

Table 3 Haemodynamic,respiratory data And sedation scores. BM(n=25) RM(n=25) p Baseline :- HR,MAP,SpO2,RR,sed ation score ns 1 min after block -MAP 76.8(19.7) 88.7(14.9)<0.05 After incision 10 min after incision 20 min after incision

Table 4 Side effects.(ns) BM (n=25) RM (n=25) Bradycradia 0(0) Hypotension 10(40) Nausea 6(24) 3(12) Vomiting 2(8) 0(0) Shivering 0(0) Sedation 11(44) 9(36) Resp.distress 0(0) Pruritus 16(64) 18(72) Backache 0(0) Headache 2(8) 1(4)

DISCUSSION Similar sensory block and PO analgesia,shorter duration of motor block,less ephredine requirement,similar APGAR scores and umbilical pH and similar SE An equal dose of R. And B. (15 mg) and ropivacaine dose ~ ED50(Khaw and coll.) Prolong PO analgesia after CS RM is considered to be less potent than BM But similar two-segment regression(Chung and coll.)

DISCUSSION The equipotent ratio between B. And R. Is 3:2 or 2:1 R. Expected to lead to less cephalad spread than similar B. Dose( Parlow and coll. demon.that adding opioid alter the density and spread in CSF) Pharmacodynamic studies not know why RM=BM Further studies

DISCUSSION Previous study:-Motor block of BM > RM but dose is 3:2 but in this study dose is 1:1 PO neurological symptoms Hypotension

THANK YOU FOR YOUR ATTENTION P.Chatchawarat,MD

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