Duration of Fasting Before Surgery

In the past, duration fast before recommended operation for patient is since middle night before day operation. However, recommendations latest state that duration prolonged fasting actually not yet proven useful and actually suspected can cause effect negative like dehydration.

 

Fast before operation conducted for prevent aspirations food to airway. worry aspirations this appears in the middle 19th century when there is soldiers in Burma died after operation consequence existence vomit in the airway. Although guide simple about fast before operation has introduced since beginning 20th century, practice fast prolonged since middle night before operation has Becomes a difficult dogma changed. [1]

 

Duration of Fasting Before Surgery

Recent evidence show that by physiological, fluid clear emptied from stomach in period 2 hours since consumed. Not there is difference means volume of fluid stomach Among the last individual drink 2 hours before surgery and fasting individuals since 12–16 hours before operation elective. [2]

 

Finding that and many proof scientific other bring the experts modern anesthesia on change paradigm about optimal duration of fasting for patients who want undergo operations, including type food that can consumed approach time operation and what is needed discontinued since a few hours earlier. [3,4]

 

Destination Fast before Operation

By general, fasting before operation aim for lower risk occurrence of aspiration pneumonia. Incidence and severity of aspiration pneumonia postoperative suspected related with volume and acidity fluid incoming stomach to airway. However, because reason ethics, not yet there is human research that studies influence various volumes and levels acidity fluid incoming stomach to airway against incidence of aspiration pneumonia.

 

In the end, the experts think that the pH of the liquid stomach >2.5 and fluid volume stomach <25 ml to limitation conventional safe (risky) low aspirations. For decrease fluid volume stomach and keep level proper acidity, pre - operative fasting becomes recommendation for all patient from various group age. [5,6]

 

Effect Fast before Operation on Plasma Volume and Hydration Status

Fast before surgery (pre-operative) is suspected have effect negative in the form of dehydration and hypovolemia. However, until moment this not yet there are studies comparing blood volume before and after fast for test guess that.

 

There is data from study against 53 patients women who live anesthesia general preceded preoperative fasting for 10 hours. From research that, is known that participants ' mean plasma volume no different mean with individual mean plasma volume healthy that is not fasting (4123 ± 589 ml vs 3882 ± 366 ml; p > 0.05). [7]

 

However, the result the need be observed by careful remember measurement of plasma volume before fast no done and all participant is patient with malignancy the cervix to be undergo hysterectomy, so that character no representative for spectrum patient surgery others. [7]

 

in line with findings, another study found that fasting 8 hours before operation no related with change hemodynamics nor hypovolemia. With use elevation limbs by passive as replacement indicator response hemodynamics, 100 patients fasted 8 hours before operation. Then, researcher evaluate response patient against elevation test leg, pressure fill, and stroke volume heart with echocardiography. [7]

 

Study results the show that fasting 8 hours no increase proportion patients who have elevation test results limbs positive. Besides that, no there is change meaning on indicator hemodynamics during echocardiography. Finding this support results study previously stated that not yet there is proof assertive about influence pre - operative fasting negative to changes in plasma volume and hydration status patient surgery. [7]

 

Scientific Evidence about Duration Fast before Safe Operation

Although fast up to 8–10 hours pre-operative no show effect physiology that compromises the patient 's plasma volume status, p the no Becomes base proof scientific main and safe for recommend patient fast since middle night before operation.

 

Evidence about Duration Fast before Surgery on Adults

For fasting in adults, evidence latest even show that consumption fluid clear (water, clear juice, coffee, and tea without milk) up to 2 hours before operation considered safe for performed by the patient who will undergo operation elective. [3,4]

 

This thing based on the findings of a meta - analysis which stated that that Fasting 2–4 hours before operation, compared fasting >4 hours like before, related with drop complaint thirsty and hungry by subjective. Fast only 2–4 hours is also related with indicator risk minimal aspiration (fluid volume stomach <25 ml and gastric pH >2.5). [4]

 

However, for moment this, not yet there is proof scientific for confirm limitation time fast food safe solid before operation. Something studies show that food light (toast and tea) consumed 2–4 hours before operation no increase fluid volume stomach moment induction anesthesia done.

 

However, the relationship with risk of aspiration pneumonia still need researched more carry on because still there is possibility existence residue food solid in the stomach that hasn't been could evaluated by perfect based on existing method moment this. On consideration that, the experts set consensus for limit intake food congested at least 6 hours before operation. [3]

 

Evidence about Duration Fast before Surgery on Children

Scientific evidence about limitation time fast pre-operative food and drink for the children who will undergo surgery show that consumption liquid 2 hours before operation no related with decrease in fluid volume stomach moment induction anesthesia.

 

More carry on again, no there is difference means stomach volume after consumption food light both 4 hours and 6 hours before operation. As a result, some expert consider return to practice total fasting (nil by mouth) for reduce risk aspirations. Some other experts actually think that duration fast shortened just 2 hours remember Thing the no related with decrease in gastric volume predictor risk aspirations. [8]

 

children by physiological have rate more metabolic height and reserve more glycogen low than adults. That thing increase risk hypoglycemia consequence fasting too long before operation. In fact, there are proof incident hypoglycemia by 28% in toddlers who fasted 6 hours before operation.

 

On consideration that, patient the child who will undergo surgery recommended for fast food solid (including semi- solid foods and dairy products) since 6 hours and fasting fluid clear since 2 hours before induction anesthesia. This thing considered beneficial for ensure that the patient child Becomes calm down, no fussy consequence hungry nor thirsty too much, as well avoid from risk disturbance metabolic consequence prolonged fasting. [8]

 

Conclusion

Patient adults and children recommended for fast drink fluid clear (including water, tea, and coffee without milk) since 2 hours before induction anesthesia. Temporary that, fasting food solid (including semi - solid foods and dairy products) in patients adults and children should conducted since 6 hours before induction anesthesia.

 

However, research more carry on still need conducted for evaluate is duration fast food and drink for children could more shortened. Besides that, the study that reviewed repeat relevance of traditional parameters (volume and acidity stomach) which is this made indicator the risk of aspiration pneumonia is still need done.

 

Sources:

1.     Hamid S. Pre-operative fasting - a patient centered approach. BMJ Qual Improv Reports. 2014;2(2):u605.w 1252. http://qir.bmj.com/lookup/doi/10.1136/bmjquality.u605.w1252

2.     Maltby JR. Fasting from midnight - the history behind the dogma. Best Practice Res Clin Anaesthesiol. 2006;20(3):363–78.

3.     Smith I, Kranke P, Murat I, et al. Perioperative fasting in adults and children: Guidelines from the European Society of Anesthesiology. Eur J Anaesthesiol. 2011;28(8):556–69.

4.     American Society of Anesthesiologists Task Force on Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. Anesthesiology. 2017 Mar;126(3):376–93.

5.     Brady MC, Kinn S, Ness V, et al. Preoperative fasting for preventing perioperative complications in children. Cochrane Database System Rev. 2009;(4). http://doi.wiley.com/10.1002/14651858.CD005285.pub2

6.     Brady MC, Kinn S, Stuart P, Ness V. Preoperative fasting for adults to prevent perioperative complications. Cochrane Database System Rev. 2003;(4). http://doi.wiley.com/10.1002/14651858.CD004423

7.     Jacob M, Chappell D, Conzen P, et al. Blood volume is normal after pre-operative overnight fasting. Acta Anesthesiol Scand. 2008;52(4):522–9.

8.     Frykholm P, Schindler E, Sümpelmann R, et al. Preoperative fasting in children: a review of the existing guidelines and recent developments. Br J Anaesth. 2017;6: 1–6. http://linkinghub.elsevier.com/retrieve/pii/S0007091217540751