Desflurane reduces the effective therapeutic infusion rate (ETI) of cisatracurium more than isoflurane, sevoflurane, or propofol.
OBJECTIVE
The present study investigated the interaction between the cumulative dose requirements of cisatracurium and anesthesia with isoflurane, sevoflurane, desflurane or propofol using closed-loop feedback control.


METHODS
Fifty-six patients (18-85 yr, vitrectomies of more than one hour) were studied. In the volatile anesthetics groups, anesthesia was maintained by 1.3 MAC of isoflurane, sevoflurane or desflurane; in the propofol group, anesthesia was maintained by a continuous infusion of 6-8 mg.kg(-1).hr(-1) propofol. After bolus application of 0.1 mg.kg(-1) cisatracurium, a T1%-level of 10% of control level (train-of-four stimulation every 20 sec) was maintained using closed-loop feedback controlled infusion of cisatracurium. The effective therapeutic infusion rate (ETI) was estimated from the asymptotic steady-state infusion rate Iss. The Iss was derived from fitting an asymptotic line to the measured cumulative dose requirement curve. The ETI of the different groups was compared using Kruskal-Wallis- test, followed by rank sum test, corrected for the number of comparisons, P <0.05 was regarded as showing significant difference.


RESULTS
ETI in the isoflurane group was 35.6 +/- 8.6 microg.m(-2).min(-1), in the sevoflurane group 36.4+/- 11.9 microg m(-2).min(-1), in the desflurane group 23.8 +/- 6.3 microg.m(-2).min(-1). The ETI of the volatile anesthetic groups were all significantly lower than the ETI in the propofol group at 61.7 +/- 25.3 microg.m(-2).min(-1) (P <0.002). The ETI in the desflurane group was significantly lower than in all other groups (P <0.02).


CONCLUSIONS
In comparison to propofol, isoflurane, sevoflurane and desflurane reduce the cumulative dose requirements of cisatracurium to maintain a 90% neuromuscular blockade by 42%, 41% and 60%, respectively.
Hemmerling
T M
TM
Department of Anesthesiology, University of Erlangen-Nuremberg, Germany. thomashemmerling@hotmail.com
Schuettler
J
J
Schwilden
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D018686:Anesthetics, Intravenous / Q000009:adverse effects*; D001279:Atracurium / Q000008:administration & dosage; D000077335:Desflurane; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007530:Isoflurane / Q000009:adverse effects* / Q000031:analogs & derivatives; D008297:Male; D008738:Methyl Ethers / Q000009:adverse effects*; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage; D015742:Propofol / Q000009:adverse effects*; D000077149:Sevoflurane; D014821:Vitrectomy
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D000077149:Sevoflurane; D000077335:Desflurane; D007530:Isoflurane; D015742:Propofol