Serum Glucose and Ketone Concentrations in Fasted Children Aged 6-12 Months Having Elective Surgery.

BACKGROUND

Perioperative hypoglycemia during elective surgery may have serious consequences in neonates; however, infants under 12 months of age have traditionally been assumed to be at lower risk of hypoglycemia and ketosis.

AIMS: The aim of this multi-centre prospective observational study was to identify the incidence of hypoglycemia and ketosis in children aged 6-12 months having elective surgery. Secondary aims were to identify factors associated with serum glucose concentrations and ketone concentrations at the beginning and end of anesthesia.

METHODS

Serum glucose and ketone concentrations were tested at the induction of anesthesia and at the end of anesthesia. For this study, hypoglycemia was defined as glucose < 3.0 mmol/L and ketosis was defined as ketones being > 0.6 mmol/L. Data on types of fluids given, fasting time for fluids, milks and solids, and vital signs were collected.

RESULTS

The study enrolled 158 participants between 2019 and 2021 at three tertiary pediatric hospitals in Australia. There were 6 cases of hypoglycemia (3.8%) recorded at induction of anesthesia with only 1 at the end of the case. At induction, 54 (34.6%) patients were ketotic with 76 ketotic (48.7%) at the end of the procedure. At induction there was no evidence for a difference between states with differing fasting guidelines in the incidence of hypoglycemia; The Royal Children's Hospital (RCH) 4 (4.1%), Queensland hospitals 2 (3.6%) risk ratio 1.13, and no evidence for a difference in ketosis; RCH 31 (32%), Queensland hospitals 18 (47.4%) risk ratio 0.76, 95% CI 0.45 to 1.17, p = 0.22. There was also no evidence for a difference in serum glucose concentrations; RCH mean 4.6 mmol/L (SD 0.84), Queensland hospitals' mean 4.7 mmol/L (SD 0.83), differences in mean -0.07 (95% CI -0.35 to 0.20) p = 0.60. However, there was evidence for a difference in ketones with median at RCH at 0.4 (IQR 0.2,0.7), Queensland at 0.6 mmol/L (IQR 0.3,0.9) however it is clinically insignificant. Serum glucose and ketone concentrations are related to milk fasting time. Increasing milk fasting times increases ketone concentrations and decreases serum glucose concentrations.

CONCLUSIONS

The study showed that for young children undergoing elective surgery, there is a risk of hypoglycemia and ketosis.