Target controlled infusion of propofol for induction and maintenance of anaesthesia using the paedfusor: an open pilot study.

BACKGROUND

The aim of this study was to evaluate the ease of use and efficacy of the Paedfusor, a computer controlled propofol infusion device with software appropriate for children down to the age of 6 months and weighing 5 kg.

METHODS

Thirty ASA I children, aged 6 months to 16 years, who were scheduled for elective surgery, were anaesthetized using the Paedfusor, programmed for the child's age and weight. Vital signs were recorded at 1-min intervals during induction and every 3 min thereafter. Patients breathed spontaneously through a laryngeal mask airway (LMATM) and perioperative analgesia was provided by a regional block. Target plasma and calculated effector site propofol readings were recorded on insertion of the LMA, insertion of regional block, surgical incision and on removal of LMA.

RESULTS

A target plasma propofol level of 8 micro g.ml-1 universally induced sleep within 1 min. Spontaneous respiration was maintained in the majority of patients with no cases of laryngospasm. Mean calculated effector site concentration was 4.29 micro g.ml-1 for insertion of the LMA and 2.78 micro g.ml-1 for LMA removal. Fifty-seven percent moved on insertion of the local anaesthetic block and 30% responded to surgical stimulation. Mean heart rates increased slightly after each stimulus, returning thereafter to baseline values. Blood pressure remained stable. No relationship between the duration of infusion, total propofol requirements and time to patient awakening was found. The average total propofol dose was high, being highest in the youngest groups. Vital signs were within acceptable safety limits throughout.

CONCLUSIONS

This open study confirms the ease of use, clinical efficacy and absence of adverse effects of the Paedfusor for the induction and maintenance of anaesthesia in healthy children aged over 6 months undergoing elective surgery.