M. Abdulatif et E. Taylouni, SURGEON-CONTROLLED MIVACURIUM ADMINISTRATION DURING ELECTIVE CESAREAN-SECTION, Canadian journal of anaesthesia, 42(2), 1995, pp. 96-102
We have compared the dose requirements and recovery characteristics of
a continuous mivacurium infusion given by the anaesthetist to maintai
n 95-100% block at the hand muscles with that of a surgeon-controlled,
on-demand dosing technique based on the direct assessment of abdomina
l muscle tone during elective Caesarean section. Twenty-four full term
pregnant patients were included. A rapid-sequence induction using thi
opentone 3-5 mg . kg(-1) and succinylcholine 1 mg . kg(-1) was used An
aesthesia was maintained with fentanyl, N2O and isoflurane 0.5%. The m
echanomyographic response of the adductor pollicis muscle to supramaxi
mal train-of-four (TOF) ulnar nerve stimulation was recorded. Muscle r
elaxation was achieved initially with mivacurium 0.1 mg . kg(-1) follo
wed either by a continuous infusion of mivacurium to maintain 95-100%
block at the adductor pollicis muscle (n = 12) or by surgeon-controlle
d relaxation (SCR) technique using a syringe pump for patient-controll
ed analgesia to administer on-demand doses of mivacurium 0.05 mg kg(-1
) (n = 12). The lockout interval was three minutes and the maximum hou
rly dose of mivacurium allowed was 0.06 mg . kg(-1). The total doses o
f mivacurium (mean +/- SD) were 23.2 +/- 10.4 and 12.4 +/- 3.5 mg in t
he infusion and SCR groups, P < 0.01. On-demand, surgeon-controlled do
ses of mivacurium were injected at a mean of T-1 42.3 +/- 36%. At the
end of surgery, T-1 and TOF ratio were respectively 16.7 +/- 13%, 5 +/
- 10% and 48 +/- 37%, 30 +/- 24% in the infusion and SCR groups. Five
patients in the SCR group and one patient in the infusion group did no
t receive antagonist at the end of surgery. The time to adequate recov
ery, TOF 75%, after skin closure was 8.2 +/- 5.3 and 5.3 +/- 4 min in
the infusion and SCR groups, P = 0.05. It is concluded that, compared
with a continuous mivacurium infusion, the SCR technique is associated
with reduced mivacurium requirements a substantial degree of neuromus
cular recovery al the end of surgery and a reduced need for neostigmin
e reversal in full term pregnant patients undergoing elective Caesarea
n section.