Metabolic and Inflammatory Benefits of Reducing Preoperative Fasting Time in Pediatric Surgery

1 Santa Casa de Misericórdia de Cuiabá-MT, Cirurgia Pediátrica Cuiabá MT Brasil. 2 Centro Universitário de Várzea Grande, Faculdade de Medicina Várzea Grande MT Brasil. 3 SEDARE Anestesiologia, Anestesiologia Cuiabá MT Brasil. 4 Universidade Federal de Mato Grosso, Faculdade de Nutrição Cuiabá MT Brasil. Carvalho Metabolic and Inflammatory Benefits of Reducing Preoperative Fasting Time in Pediatric Surgery 2 Rev Col Bras Cir 47:e20202353 Absolute fasting from 00:00, on the night before the procedure, is the most common prescription by surgeons. This is an easy-to-follow recommendation, widely accepted, that does not require calculations of any kind and can be easily explained to patients and their families. However, this prescription does not specify the fasting time required for each type of food, does not consider the scheduled time for the surgical procedure the next day and does not take into account the constant delays regarding the operating room agenda. In addition, prolonged fasting times do not promote an additional reduction of gastric residual volumes or increase the safety of the procedure. Consuming carbohydrate-rich beverages, which can be used up to two hours before the surgical procedure, reduces the preoperative fasting time. Studies enrolling adults have described the benefits of this protocol, as it leads to much better wellbeing, better glycemic metabolism (with decreased postoperative insulin resistance up to 50%) and a reduction of lean body mass loss, leading to better surgical recovery12-14. Some of these benefits in children have also been published, such as lower insulin concentrations and lower insulin resistance in patients undergoing reduced fasting times15,16. However, the reduction of the preoperative fasting time in children, with the intake of carbohydrate-rich beverages, is a topic that still needs more research. There is no extensive literature investigation about the acute inflammatory phase response associated with this protocol in pediatric patients. Our research group has previously studied the safety of reducing the preoperative fasting time using a drink with maltodextrin during a national task force of pediatric surgery, obtaining good results17. The ACERTO18 Project has encouraged these paradigm changes in Brazil, but once again, there is no study regarding children. Thus, this work aims to evaluate the metabolic and inflammatory effects of reducing the preoperative fasting, using carbohydrate-rich beverages, in preschool children undergoing inguinal herniorrhaphy.

However, current studies show that these guidelines have not been performed routinely in pediatric surgical hospitals, and several publications highlight a long time of fasting in pediatric patients [4][5][6] . This long period of preoperative fasting has clinical and metabolic consequences for these patients.
Children undergoing prolonged fasting have higher rates of hunger and thirst, irritability, anxiety, discomfort, malaise, dehydration (which can hinder venous access), headache and delayed surgical recovery [7][8][9] . Also, these patients present depletion of glycogen stores and increased gluconeogenesis, as well as worsening of catabolism with higher plasma levels of ketone bodies and fatty acids, risk of hyperglycemia and insulin resistance in the postoperative period 10,11 . Original article

Rev Col Bras Cir 47:e20202353
Absolute fasting from 00:00, on the night before the procedure, is the most common prescription by surgeons. This is an easy-to-follow recommendation, widely accepted, that does not require calculations of any kind and can be easily explained to patients and their families. However, this prescription does not specify the fasting time required for each type of food, does not consider the scheduled time for the surgical procedure the next day and does not take into account the constant delays regarding the operating room agenda. In addition, prolonged fasting times do not promote an additional reduction of gastric residual volumes or increase the safety of the procedure.
Consuming carbohydrate-rich beverages, which can be used up to two hours before the surgical procedure, reduces the preoperative fasting time. Studies enrolling adults have described the benefits of this protocol, as it leads to much better wellbeing, better glycemic metabolism (with decreased postoperative insulin resistance up to 50%) and a reduction of lean body mass loss, leading to better surgical recovery [12][13][14] . Some of these benefits in children have also been published, such as lower insulin concentrations and lower insulin resistance in patients undergoing reduced fasting times 15 was offered approximately two hours before the operation. Anesthetic induction was performed with a mask and inhalation anesthetic (Sevorane®) in all children. After the patient's sedation, venous access in the upper limb was performed with Abocath®, in order to collect a blood sample regarded as "preoperative" (this access was kept salinized and exclusive for extraction of blood samples).

Rev Col Bras Cir 47:e20202353
Another venous access in the contralateral upper limb was also performed to provide venous hydration and anesthetic medications. Immediately after the end of the operation and before the patient awoke from anesthesia, a blood sample named "postoperative" was collected (using the exclusive access for blood sampling). Blood samples were sent to the laboratory for quantification of albumin, interleukin 6 (IL-6), blood glucose, insulin and C-reactive protein (PCR).
Insulin resistance was calculated using the HOMA-         The results of the current study, both metabolic and inflammatory, are relevant and suggest that the reduction of fasting time with carbohydrate-rich beverages up to two hours before anesthetic induction in children undergoing elective procedures is seen.
Our Using a population of only 40 patients can be a limitation, considering that with a higher number of cases, we could probably find more considerable differences in different variables, such as blood glucose, insulin and insulin resistance.
Furthermore, the blood collection in the postoperative period was right at the end of the surgical procedure (for ethical reasons, before the removal of the venous access). We could have found a more significant difference between the groups if the collection was performed a few hours after the end of the operation, due to the maximum serum peak reached by cytokine IL-6 six hours after the procedure 24 . In addition, we chose inguinal herniorrhaphy as the surgical procedure, which is a minor trauma procedure and represents a short surgical time, with rapid patient recovery. We did not assess differences in clinical parameters between groups, which we consider a potential area for future studies.