Comparison of minimal fresh gas requirements of baby enclosed afferent reservoir and Jackson Rees anesthetic circuit for general anesthesia in spontaneously breathing children.

OBJECTIVE

The authors compared the baby enclosed afferent reservoir (Baby EAR) with the Jackson-Rees (JR) anesthesia circuit for the minimal fresh gas flow (FGF) requirement with no and clinically acceptable rebreathing in spontaneous breathing anesthesia among pediatric patients.

MATERIAL AND METHOD

The present study was a randomized crossover study. Twenty patients, weighing 5 to 20 kg with ASA physical status I-II were enrolled. They were allocated to group 1 (EAR-JR) starting with Baby EAR then switching to JR or group 2 (JR-EAR), reversedpattern. After induction and intubation, anesthesia was maintainedwith a N2O/O2 combination with sevoflurane 1 to 3% and fentanyl. Starting with the first circuit, all patients were spontaneously ventilated with FGF 500 mL/kg/min for 10 minutes, and then gradually decreased by 50 mL/kg/min every five minutes. End-tidal CO2 (ETCO) and inspired minimum CO2 (imCO) were recorded until rebreathing (imCO2 >2 mmHg) occurred and continued until rebreathing was not clinically acceptable (imCO2 >6 mmHg). The anesthesia breathing circuit was switched and the procedure repeated.

RESULTS

The minimal FGF at no rebreathing of Baby EAR and JR were 192.5±76.6 and 347.5±108.2 mL/kg/min; p<0.001. At acceptable rebreathing, the values were 117.5±46.7 and 227.6±90.6 mL/kg/min; p< 0. 001.

CONCLUSION

Baby EAR can be used safely, effectively, and requires less FGF than JR in pediatric anesthesia in patients weighing 5 to 20 kg.