A clinical determination of optimal fresh gas flow in a baby EAR circuit.

OBJECTIVE: Baby EAR circuit is a new modified enclosed afferent reservoir anesthetic breathing system for pediatric patients. By following His Majesty the King of Thailand's self-sufficiency philosophy, the circuit is simple and made of low-cost and easy-to-find materials found in the operating room. This present study was to investigate clinical use of the circuit and to find the optimal fresh gas flow in clinical setting. MATERIAL AND METHOD: A prospective descriptive study was conducted in pediatric patients, weighed 5-20 kg, anesthetized for surgery. The Baby EAR breathing circuit was used for general anesthesia with endotracheal tube and control ventilation. Different fresh gas flow of 3, 2.5, 2 and 1.5 liter per minute (LPM) was used consecutively. The authors recorded end-tidal carbon dioxide (EtCO2) and mean inspiratory carbon dioxide (ImCO2) while using fresh gas flow at 3, 2.5, 2, and 1.5 LPM. EtCO2 of 35-45 mmHg and ImCO2 of < 6 mmHg were considered clinically acceptable. RESULTS: Fifty patients were enrolled. Mean value (95% CI) of EtCO2 at fresh gas flow rate of 1.5, 2, 2.5, and 3 LPM were 39.6 (39.2, 40.9), 36.7 (35.5, 37.8), 35.4 (34.3, 36.4), and 35.4 (34.3, 36.4) mmHg respectively. Mean value (95% CI) of ImCO2 at fresh gas flow rate of 1.5, 2, 2.5, and 3 LPM were 4.0 (3.0, 4.9), 2.4 (1.7, 3.0), 1.8 (0.9, 2.6), and 1.3 (0.9, 1.7) mmHg respectively. Percentage of patients (95% CI) who had clinically acceptable EtCO2 and ImCO2 at fresh gas flow rate of 1.5, 2, 2.5, and 3 LPM were 70% (56.2, 80.9), 92% (81.2, 96.8), 98% (89.5, 99.6), and 100% (92.9, 100) respectively. No patients had serious complications. CONCLUSION: Baby EAR circuit can be made economically and used safely for general anesthesia with control ventilation in pediatric patients weighing 5 to 20 kg at optimal fresh gas flow of 3 LPM.

Surveillance of anesthetic related complications at Srinagarind Hospital, Khon Kaen University, Thailand.

OBJECTIVE: To identify the incidence of common anesthetic complications in 2003 at Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand and find the strategies for prevention. MATERIAL AND METHOD: The study was part of a multi-center study conducted by the Thai Royal College of Anesthesiologists to survey anesthetic related complications in Thailand in 2003. The authors collected data from all the cases receiving anesthesia service at Srinagarind Hospital between January 1 and December 31, 2003, to report the incidence of common anesthetic complications and to assess the need to improve the quality of service. This was a prospective, descriptive study. When any anesthetic complications occurred, they were reported by anesthesia personnel and anesthesiologists. The reporting forms comprised four categories of complications, viz.: respiratory, cardiovascular, neurological and others. Each category of complications has a guidebook for reference in order to correctly fill out the form. All the forms were verified by the principal author then included in the present study. RESULTS: A total of 10,607 patients were included and among these 268 incidents were recorded. The common incidents per 10,000 were desaturation (95.22), cardiac arrest (44.31), re-intubation (29.23), equipment failure (19.80) and difficult intubation (18.86). Main contributing factors were insufficient knowledge and inappropriate decisions. Suggested corrective strategies included quality assurance activities, additional training and improved supervision. CONCLUSION: Despite practical prevention guidelines being in place, the most common anesthesia incident at Srinagarind Hospital was respiratory incident. Continuing quality improvement is needed.