Possible Effect of Peri-operative Desaturation on Growth and Intelligence Outcome in Children Undergone General Anesthesia at a Tertiary Care Hospital in Southern Thailand

Material and methods A historical and concurrent follow up study was conducted at Songklanagarind Hospital, an 853-bed tertiary care hospital in southern Thailand, after approval by the Ethics Committee, Prince of Songkla University at November 15th, 2012. Written informed consent was signed by all parents who participated in the study.

Participants Children aged ≤ 5 years old who received general anesthesia (GA)and developed intraoperative or post-anesthetic care unit (PACU)desaturation were included in the study and was defined as desaturation group. The exclusion criteria were ASA (American Society of Anesthesiologist) classification 4 or 5, preoperative oxygen saturation < 95% at room air, required preoperative endotracheal tube intubation (ETT) or mechanical ventilation, had congenital heart disease or open heart surgery, had neurosurgery, had preoperative delayed development, and had perinatal hypoxia or fetal growth retardation. Perioperative desaturation was defined as oxygen saturation < 95% for more than 10 seconds [9]. Children in desaturation group were matched with children in non-desaturation group one per one by the same sex, same age within the same year of general anesthesia, same type of surgery and same technique of anesthesia. Non-desaturation group was defined as children who did not developed perioperative respiratory events eg; desaturation, laryngospasm, bronchospasm, upper airway obstruction and reintubation. After a child from desaturation group was identified, one child from non-desaturation group was randomly selected from the lists of 3 to 4 children matching with same demographic, same surgery and same anesthesia profile above. The parents of both groups were contacted by the investigator by phone call and invitation postcard. If selected child in the non-desaturation group was declined by the parents or could not be reached, the next child on the list would be randomly selected.

Outcome of interest The outcomes of interest were divided into growth developmental outcome and intelligence outcome. The intelligence outcome and growth developmental outcome were evaluated at least 6 months after exposing to general anesthesia. Children aged between at least 2 years and not more than 9 years were equally compared the outcomes of interest between desaturation and non-desaturation groups.

For growth development outcome, preoperative body weight, percentile weight, height and percentile height were compared with the current body weight, current height, percentile weight and percentile height. Month age of first meaning word and month age of first walk will be asked.

The main outcome will be intelligence score or intelligence quotient (IQ) score. There are two intelligence tests available in Songklanagarind hospital which are suitable for testing intelligence outcome in this study; the Standford Binet form L-M and Wechsler Intelligence Scale for Children, 3rd edition (WISC-III). The same aged of children in desaturation and non-desaturation groups were appointed to have an IQ test during the study period. A child psychologist (T.D.) performed the IQ test in all children. The Standford Binet form L-M was the main intelligence test used in our study. It measures cognitive ability regarding verbal reasoning, quantitative reasoning, abstract and visual reasoning and short-term memory skills and a wide range of IQ score varying from 20 to 140. The suitable age for using the Standford Binet form L-M is between 2 to 7 years old. The WISC-III test was used for supplemental test for children who reached the ceiling aged of 7 years and still could not complete IQ measurement. The WISC-III consists of 2 main subtests eg; the verbal subtests and performance subtests (nonverbal subtest) which the average IQ score was used to compared between 2 groups. The same IQ score of each IQ test was considered to have the similar level of intelligence outcome in the study. The type of IQ test was recorded and compared between 2 groups.