Comparison of train-of-four and posttetanic response as guides for endotracheal intubation in children

Abstract

Study Objective: To evaluate and compare the predictive values of the absence of train-of-four (TOF) or Posttetanic response as guides for endotracheal intubation in children. Design: Prospective controlled study in children. Setting: Induction of anesthesia and endotracheal intubation at a university-affiliated hospital. Patients: Thirty pediatric patients age 1 to 10 years, ASA physical status I, who were undergoing elective surgery were divided into two equal groups. Interventions: Anesthesia was induced with halothane and maintained at 1% inspired concentration. Fifteen children were stimulated with the TOF (2 Hz for 2 seconds) technique and 15 with the twitch-tetanus-twitch sequence. All the patients received atracurium 0.4 mg/kg. Upon abolishment of the TOF or tetanus-twitch sequence, endotracheal intubation was performed and the conditions for intubation were evaluated. Measurements and Main Results: In the group of Patients stimulated by the TOF technique, the neuromuscular response was ablated in 1.7 ± 0.1 minutes, a significantly shorter time than in those stimulated by the tetanus-twitch sequence (4.0 ± 0.4 minutes; p < 0.0001). Conditions for intubation did not differ between the two groups. Conclusions: Good intubating conditions can generally be counted on when the TOF has disappeared; additional waiting for the disappearance of posttetanic response is unnecessary. The observation that the disappearance of the tetanus-twitch sequence is a good indicator of deep neuromuscular blockade during recovery from atracurium in children cannot be extrapolated to the induction period.