Residual neuromuscular blockade can be evaluated using acceleromyography, tactile assessment of train-of-four (TOF), double-burst stimulation (DBS), 50-Hz tetanus, or 100-Hz tetanus. Nerve stimulation can be at the hand or the wrist. We compared all these tests at both sites of stimulation. Rocuronium was given to 32 patients under sevoflurane anesthesia. The mechanomyographic adductor pollicis TOF ratio was measured at one extremity. In the other, stimulation was at the hand or the wrist, by random allocation, and the acceleromyographic TOF ratio was measured. During recovery, a blinded observer estimated tactile fade. The TOF fade became undetectable when mechanomyographic TOF ratio was (mean +/- sd) 0.31 +/- 0.15. For DBS, this threshold was 0.76 +/- 0.11. For 50-Hz tetanus, it was 0.31 +/- 0.15. For 100-Hz tetanus, it was 0.88 +/- 0.18, with a range of 0.14-1.00. These tactile responses were the same for hand and wrist stimulation. When acceleromyographic TOF ratio reached 1.0, the mechanomyographic TOF ratio was 0.89 +/- 0.06. With stimulation in the hand, acceleromyographic TOF ratio >1.0 was less frequent than at the wrist. To exclude residual paralysis, TOF, DBS, and 50-Hz tetanus are inadequate, 100-Hz tetanus is unreliable, and acceleromyography performs best.

Purpose We investigated the effects of a combination of low-dose fentanyl-midazolam premedication on the speed of inhaled induction with sevoflurane and ProSeal TM laryngeal mask airway (PLMA) insertion conditions. Methods Eighty adult patients undergoing elective surgery were randomized in a double-blind fashion to receive either a normal saline placebo (Group PLAC) or a fentanyl 0.6 lg Á kg -1 and midazolam 9 lg Á kg -1 premedication (Group FM) 5 min before tidal volume sevoflurane 8%/O 2 induction. Anxiety levels, times to loss of eyelash reflex (LER) and PLMA insertion, and cardiorespiratory data were recorded. Results Times to LER (Group PLAC: 66 ± 34 sec vs Group FM: 47 ± 18 sec, P = 0.0027, difference = 19 sec: 95% confidence interval [CI] 7-31 sec) and to PLMA insertion (Group PLAC: 186 ± 80 sec vs Group FM: 119 ± 44 sec, P \ 0.0001, difference = 68 sec: 95% CI 39-97 sec) were shorter following FM. After PLMA insertion, end-tidal sevoflurane concentration (EtSevo) was lower and end-tidal CO 2 (EtCO 2 ) was higher following FM. Respiratory rate (RR) was lower with FM, but there was no difference regarding tidal volume. Adverse events, such as movements and apnea, occurred more often in Group PLAC. Systolic blood pressure (SBP) and heart rate (HR) during induction were both lower with FM. Anxiety level after premedication was lower following FM administration. All participants remembered the face mask being applied in Group PLAC vs 69% in Group FM, P \ 0.0001. Conclusion Administration of a low-dose fentanylmidazolam combination prior to sevoflurane induction decreases time to LER and allows for more rapid and less eventful PLMA insertion. Both SBP and HR were lower when premedication was administered. Patients receiving premedication were less anxious and less likely to remember the face mask. However, premedication was associated with a lower RR and increased EtCO 2 values following PLMA insertion, in spite of lower EtSevo concentrations. (ClinicalTrials.gov ID NCT00723164). RésuméObjectif Nous avons examine´les effets d'une combinaison de fentanyl -midazolam a`faible dose en pre´me´dication sur la vitesse d'une induction par inhalation de se´voflurane et sur les conditions d'insertion du masque larynge´Pro-Seal TM (PLMA). Méthode Quatre-vingts patients adultes subissant une chirurgie non urgente ont e´te´randomise´s en double aveugle a`recevoir soit un placebo de solution sale´e (groupe PLAC) ou une pre´me´dication compose´e de fentanyl 0,6 lgÁkg -1 et midazolam 9 lgÁkg -1 (groupe FM) cinq minutes avant l'induction avec du se´voflurane 8 %/O 2 av olume courant. Les niveaux d'anxie´te´, le temps jusqu'a`la perte du re´flexe ciliaire (PRC) et l'insertion du PLMA ainsi que les donne´es cardiorespiratoires ont e´te´enregistre´es. Résultats Les temps jusqu'a`PRC (groupe PLAC : 66 ± 34 secondes vs groupe FM : 47 ± 18 secondes, P = 0,0027, diffe´rence = 19 secondes : intervalle de confiance [IC] 95 % 7-31 secondes) et jusqu'a`insertion du PLMA (groupe PLAC : 186 ± 80 secondes vs groupe FM : 119 ± 44 s...