Nutrition

Image credit: Principles of Correct Diet, Yuan Dynasty 1330

Nutrition

Nov 2, 2015 0
General medicine,general surgery,onthepods

James talks to Associate Professor Charbel Sandroussi about nutrition. Nutrition is an important topic that many junior (and senior) doctors don’t know much about.

Summary Writer:  George McClintock

Editor:  James Edwards

Interviewee:  Charbel Sandroussi

About Charbel Sandroussi

Associate Professor Charbel Sandroussi is a Specialist Surgeon in hepatobiliary, upper gastrointestinal, transplantation and general surgery at Royal Prince Alfred and the Mater Hospitals in Sydney. Charbel’s clinical interests are live donor liver transplantation, complex liver and pancreas resection including major vascular resection and organ preservation techniques in oncology. He has published and presented on transplantation and hepatobiliary surgery. Charbel’s research interests are in complex vascular resection for cancer, the impact of neoadjuvant and adjuvant treatment on the recurrence of hepatocellular cancer after resection and transplantation and downstaging of pancreas cancers that are borderline for resection.

Nutrition

With Associate Professor Charbel Sandroussi, Consultant Upper GI Surgeon at Royal Prince Alfred Hospital, New South Wales, Australia

Introduction

Nutrition is an important topic that many junior (and senior) doctors do not know much about.

  • Nutrition and changes in nutritional states affect surgical outcomes. If patients have too much or too little nutrition they have more perioperative complications during their hospital stay and increased morbidity and mortality
  • Baseline nutritional status has to be taken into account because often after surgery, especially upper gastrointestinal surgery, the patients will have disordered nutrition and efforts need to be taken to restore them to their pre-operative status
  • History:
    • How has their nutrition been over the past few months?
    • Significant changes in weight
    • Significant changes in physical function
  • Examination:
    • Will often do a subjective global assessment
      • Looking at how the patient gets up out of a chair
      • How they walk around
      • How they look including features of malnutrition such as loss of fat in particular places
    • There are other factors such as the patients weight and their Body Mass Index, but these are often less important than changes in weight over a shorter period of time
  • Blood tests act as adjuncts to the history and physical exam
    • Levels of certain vitamins
    • INR – surrogate measure of vitamin K
    • Pre-albumin and albumin levels
    • Iron studies
  • In patients who have long term nutritional deficiencies, trace elements need to be tested for as they can manifest as diseases
    • Selenium
    • Manganese
    • Zinc
  • Albumin
    • Albumin is not a good marker of nutritional status in inpatients – it is an acute phase reactant so in patients with infections or who are post-operative the albumin always drops
    • In patients in the community, who are otherwise well and have not had recent changes in their nutritional status it can be a useful indicator
  • Enteral
    • Refers to any method of feeding that uses the gastrointestinal tract to deliver part or all of a person’s caloric requirements
    • In many cases it has the advantage of being able to be delivered by the patient
    • Supplemental drinks with extra calories including high levels of protein and fat
    • These supplements can also be tube fed, either into the stomach or into the intestine – depending on where the problem is
    • Enteral nutritional is always preferred if it is possible. However it relies on a functional gastrointestinal tract
      • Without functional swallowing and gastric emptying any enteral feed can become an aspiration risk
      • Other complications include those related to the enteral tubes; which can leak or perforate viscera and in rare cases in patients with high vasopressor requirements can enter a low flow state in the bowel and the feed can cause pressure build up and induce necrosis of the intestine
  • Parenteral nutrition
    • Intravenous nutrition
    • Total replacement of the persons caloric, lipid, amino acid and sugar needs, as well as replacement of their vitamins and trace element needs intravenously
    • Most problems with parenteral nutrition are related with catheters and the delivery of the nutrition
      • Infection is unfortunately very common

Case 1

You are asked to review a patient on the upper GI surgical ward, who has developed a post-operative ileus and remains nil by mouth.

  • In a normal post-operative patient there are two schools of thought
    • In the past, we use to wait until they had established bowel sounds and bowel function before we started them on fluids and food. It is now believed to be unnecessary for the vast majority of patients even if they have a post-operative ileus (which is almost universal after major abdominal surgery)
    • More recently, there has been a move towards Enhanced Recovery after Surgery (often shortened to ERAS) which includes commencement of a liquid diet, which carries some nutrition within 24-48 hours after the operation.
  • Diet is usually upgraded as the patient tolerates. The decision is usually made to escalate daily, although it is less rigid than it used to be and often guided by the patient
  • Certain operations require certain diets however, for example patients who have had a fundoplication require a thin liquid diet for 5-7 days and then pureed for 3 weeks
  • The dietician is very important, especially for upper GI patients who often have significant nutritional deficiencies after surgery. The dietician will monitor their caloric intake, monitor the consistency and type of food they are eating and provide advice about supplementation in the perioperative period
  • They also follow them up to track their nutritional status after discharge
  • Short term TPN is used as a bridge from when patients have, for whatever reason, stopped eating to when they can start eating again
    • In someone who is unable to eat post operatively, generally we would wait 5-7 days before considering TPN. If someone has a prolonged ileus or vomiting to this point you’re never sure how long it is going to go on for
    • Entero-cutaneous fistulas, delayed gastric emptying, and other abdominal surgical complications which require temporary ceasing of enteric feeds are other indications
  • Short-gut syndrome – people who do not have enough intestine to adequately absorb nutrients. These people will often go on TPN in the perioperative period, but may need to stay on it in the long term
  • Line complications
    • Thrombophlebitis, thrombosis and emboli from the central venous line
  • Septic complications – either from the line or the TPN fluid
  • Vessel damage from the hypertonic TPN fluid
  • Electrolyte disturbances
  • The junior doctor is integral in looking after patients on TPN
  • It is the role of the junior doctor to initiate and manage
    • The routine investigations related to TPN
      • Mon/Wed/Fri routine blood tests
      • Once a week they will also have trace elements and other biochemistry such as LFTs
    • Charting of the TPN – including appropriate supplemental items such as Cernovit and trace elements
  • Base it on the bodyweight of the patient, however other factors such as sepsis or high output stomas may change the caloric requirements
    • This is decided in consultation with the dietician
    • Usually expressed as an optimum goal rate in ml/hr. The dietician or the TPN nurse practitioner will generally provide a plan to work up to the goal rate

Case 2

As a junior doctor you find that one of your regular blood tests has come back for a patient on TPN and you find that the potassium is low at 2.8, the magnesium is 0.6 and the phosphate is 0.5. What do you think has occurred and what is the appropriate management?

  • It is likely that this represents refeeding syndrome. Refeeding is an important problem in patients who are on TPN because there are physiological and neurological sequelae, which occur as a result of the refeeding. That patient should have their rate of TPN slowed significantly and then their electrolytes should be managed as otherwise
    • In this case, the patient should have an ECG given the low potassium and IV replacement should be If they need rapid replacement of the potassium (usually if there are any ECG changes) then they will need to go to the high dependency unit
  • The most important thing is that people need to eat and nutrition is vital to patient’s recovery and that should be thought about every single day when we are looking after our patients.

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Tags: #albumin,#baseline nutritional status,#BMI,#body mass index,#enteral,#malnutrition,#nutrition,#nutritional deficiencies,#nutritional states,#parenteral,#perioperative,#surgical outcomes,#trace elements,#upper gastrointestinal surgery

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