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The Recovery Process - The Role of Medical Nutrition

Published on

28 October 2019

Going under the surgeon’s knife is surprisingly common: it’s estimated that about one in twenty people worldwide undergo an operation each year1. Medical advances over the past decades mean that surgery is a safe and effective way to treat many conditions. However, any invasive procedure causes some damage to the body that we need time to recover from. The recovery process is affected by what happens before, during and after surgery.

A fast recovery is beneficial for the patient and for the health care system. Patients can get back to their normal routines faster when the recovery process runs well. Shorter recovery times mean better use of hospital resources. Nutrition can play a crucial role in recovery from surgery. Nutritional status both before and after surgery affects the recovery process2.

What happens during an operation?

All surgical operations cause injury to the area where they occur. Surgery leads to a stress response that is proportional to the extent of the intervention: minor operations will be easier to recover from than major operations due to the lower stress response to injury. Surgeons following guidelines for optimal recovery will try to use less invasive techniques to reduce the amount of injury that the operation causes3.

The stress response is a normal part of the way they body responds to injury. During surgery, there is a release of stress hormones, and the immune system is placed on high alert. As part of the response, the body breaks down protein, carbohydrate and fat reserves and puts them into circulation to help the healing process and to respond more quickly to infection. It’s this breakdown of protein that causes the body to lose muscle and inhibits long term recovery from surgery.

The Nutritionist – A Key Player in the Health Care Team

International guidelines promote Enhanced Recovery After Surgery (ERAS) list a nutritionist as a part of the surgical care team. The nutritionist has several roles throughout the preparation and post-surgical period that can aid patients in their recovery. A nutritionist discusses diet-related concerns before surgery starts and advises patients on what to expect after the surgery. The assessment of nutritional status that occurs before surgery helps the surgical team to decide on the best course of action for the operation. After surgery, the nutritionist monitors food intakes and the return to normal eating, integrating dietary advice into the patient’s recovery plan. This is particularly important for operations involving the gastrointestinal tract and abdomen2.

What Is Medical Nutrition?

Medical nutrition is a critical part of the recovery process. Prescribed under medical supervision, medical nutrition products provide the body with nutrients when normal food is not possible or efficient. They can be medical foods such as bars or drinks that provide extra nutrients in an easy-to-eat form. Specialised liquids for tube feeding help when patients cannot eat enough but the gastrointestinal tract is fully functioning. Intravenous nutrition is used when feeding by mouth or tube is not possible. A sterile nutrient solution is slowly infused through a vein into the body.

Preparation, Preparation, Preparation: Three Steps for Recovery

Ideally, patients should be assessed before surgery for their nutritional status. It is important to recognize signs of malnutrition, because malnourished patients take longer to recover. Malnutrition can be identified in several ways, most simply based on current body mass index (BMI), unintended weight loss or recent decreases in food intake4. Patients with a low BMI, particularly when they are underweight, are more likely to have a longer recovery time. If patients have recently lost weight without meaning to, it is a sign that their bodies are already under stress. A recent large drop in food intake also puts patients under metabolic stress before the operation.

Certain vitamin and mineral deficiencies are linked to poorer hospital outcomes. An investigation of hospital admissions found a longer length of stay for people with vitamin D deficiency on admission5. Anemia, which is often caused by iron deficiency, is associated with poorer hospital results6. Correcting deficiencies before surgery is prudent.

If malnutrition is identified, the health care team can decide to stabilize the condition before surgery. Foods such as high protein nutritional supplements have been shown to improve physical function when used in different settings7. High protein supplements can help reduce the drain on protein stores thus potentially conserving muscle8.

Traditionally, patients have been advised to fast before surgery, up to 24 hours9. However, recent research has not found this practice to be helpful during the operation, and it may slow the recovery process. Nowadays, patients may eat up to 6 hours before surgery, and may drink clear liquids including tea, coffee and sports drinks up to 2 hours before their operation2, 9. Being allowed to eat reduces stress for the patient and prevents a drop in glucose during the operation that contributes to poor recovery2. Nowadays, carbohydrate-rich drinks taken up to two hours before surgery are advised2.

Nutrition After the Operation

Patients are encouraged to eat normal food as soon as they feel ready after an operation2. Patients who start to eat normally after surgery have a shorter hospital stay and lower rate of complications2. However, various factors relating to the type of surgery performed and medication that has been administered may make achieving adequate nutrient intakes after surgery difficult. For example, some patients may feel nauseous after their operation. Any type of surgery to the digestive tract can cause the normal function of the intestines to slow down, which dampens appetite. Some medication can reduce the movement of the intestines and reduce the desire to eat. This can mean that patients are first placed onto tube feeding or an infusion to help them meet their nutrient needs.

After surgery, patients should be closely monitored for signs of nutritional risk. These can include poor food intakes, further weight loss after surgery, and a failure to regain normal functions. If it seems that patients are not meeting nutrient intake requirements, the feeding regimen can be changed to promote greater intakes. For example, if normal hospital foods are not adequate to help patients meet target nutrient intakes, oral nutritional supplements can be given, or a different feeding method can be started. It is advantageous to adjust quickly if patients are found to be at nutritional risk.  

Intravenous nutrition is used in patients who cannot tolerate any type of food after surgery10. This life-saving procedure was developed in the late 1960s and revolutionised the care of critically ill patients11. The infusion must contain all the nutrients needed for the recovery process: glucose, amino acids, lipids, minerals, trace elements and vitamins. Micronutrients needed to be added to the infusion solution daily to prevent loss of activity of the vitamins12. Because nutrient needs vary on the patient, and may change during the recovery process, the infusion should be monitored and individually adjusted. For example, a study found that many septic shock patients may be vitamin C deficient despite receiving a multiple-vitamin infusion from their medical according to standard care guidelines13. Increased metabolic needs from sepsis were thought to contribute to vitamin depletion.

It is important to understand how surgical procedures can damage the body and that the recovery process is impacted by what happens before, during and after surgery. Be mindful of the role vitamins and dietary supplements play in the recovery process, and options available to patients.

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