E. Nilsson et al., INTRATHECAL MORPHINE FOR POST-STERNOTOMY PAIN IN PATIENTS WITH MYASTHENIA-GRAVIS - EFFECTS ON RESPIRATORY-FUNCTION, Acta anaesthesiologica Scandinavica, 41(5), 1997, pp. 549-556
Background: Thymectomy can induce a remission or at least an improveme
nt in myasthenia gravis (MG) patients. After sternotomy MG patients wi
th compromised muscle strength need an excellent postoperative pain re
lief. This study was designed to evaluate the efficacy of intrathecal
morphine (ITM) on ventilatory function among MG patients undergoing tr
ans-sternal thymectomy, when intravenous morphine served as control. M
ethods: Twenty consecutive MG patients were randomised to receive eith
er morphine (10 mu g/kg) intrathecally at induction or intravenous mor
phine (30 mu g/kg) with a patient-controlled analgesia (PCA) device. A
naesthesia was standardised. Forced vital capacity (FVC), forced expir
atory volume in 1 s (FEV1), respiratory rate, oxygen saturation, arter
ial blood gases, pain intensity and morphine consumption were assessed
during 48 hours. Results: The mean age of the patients was 35+/-3.4 y
ears and the mean duration of the disease 1.9+/-0.5 years. According t
o Osserman's classification 70% of the patients belonged to Class IIA
and 30% to Class IIB. ITM restored ventilatory function significantly
better than iv PCA morphine. FVC recovered to 60% and FEV1 to 57% of t
he baseline values in the ITM group compared with 32% (P<0.05) and 37%
in the PCA morphine group, respectively. Postpuncture headache occurr
ed in 4/10 patients. Conclusion: Intrathecal morphine provided effecti
ve postoperative analgesia and significantly improved ventilatory func
tion when compared with intravenous morphine. (C) Acta Anaesthesiologi
ca Scandinavica 41 (1997).