Why is hydration important during surgery?

Water makes up about sixty percent of human body weight. Maintaining this balance through proper hydration is an important part of health. The body needs adequate hydration in order to maintain the right temperature, eliminate waste, protect joints, and cushion tissues.

According to the National Academy of Sciences, men require 15.5 cups, or nearly one gallon of fluid per day, while women require 11.5 cups of fluid per day.

The body maintains a normal level of hydration, medically termed “euhydration,” in many different ways. Thirst is one of the main signals that the body needs more water. Urination and sweating are two tactics the body uses to release water when there is an excess amount in the body.

In some situations – like surgery or trauma – fluid management requires more effort through outside intervention. Managing fluids (like water) during surgery is critical to recovery – particularly for patients who undergo major procedures in the abdominal area.

How is hydration managed during surgery?

For many years, it was common practice to limit food and water intake before most types of surgery. Recent recommendations have been revised to encourage preoperative hydration with a carbohydrate drink up until 2 hours before surgery. Research indicates that this approach has metabolic benefits and reduces anxiety, nausea and vomiting.

The patient care team is responsible for helping maintain fluid balance during the actual surgery, as fluids may be lost from bleeding, urination, or many situations that are best handled by physicians. Patients are again encouraged to take an active role post-operatively, after discharge from the hospital. Each patient has his or her own optimal fluid status, and so the exact amount of water needed will vary from one individual to the next. Failure to pay attention to water needs may impair wound healing or cause circulatory system complications. The benefits of proper hydration after surgery include fewer post-surgical complications, reduced hospital length of stay and enhanced patient outcomes.

Staying hydrated to improve recovery

Generally speaking, it is important to make hydration part of the recovery focus after surgery. Given all the complications associated with dehydration and overhydration, recognizing individual fluid needs is critical. Some strategies are to be more vigilant of thirst, work with a dietitian to get accurate fluid recommendations, to keep track of all types of fluid intake, and to carry a water bottle that has quantity markings to be more aware of water intake. Being aware of which foods or beverages that are liquid at body temperature is important to knowing how much fluid is consumed on a daily basis. For example, ice cubes, ice cream, gelatin desserts, and thin soups are all opportunities for fluid to enter the body.

Maintaining the right hydration level is often overlooked, because the body typically takes care of it. However, as noted above, it can be beneficial to pay more attention to fluids under special circumstances.

1. Belval et al., 2019. Practical Hydration Solutions for Sports. Nutrients. 2019 Jul; 11(7): 1550.
2. Kayilioglu et al., 2015. Postoperative fluid management. World J Crit Care Med. 2015 Aug 4; 4(3): 192–201.
3. Makaryus et al, 2018. Current concepts of fluid management in enhanced recovery pathways. British Journal of Anaesthesia, 120 (2): 376e383.