Title: Surgical Nutrition
1Surgical Nutrition
- Vic V.Vernenkar, D.O.
- St. Barnabas Hospital
- Dept. of Surgery
2Impact on Outcome
- For well nourished or mildly malnourished general
surgery patients, peri-operative nutritional
support did not improve outcome and actually was
associated with increased septic complications
after surgery both pulmonary and intra-abdominal. - For severely malnourished patients before a major
surgical procedure, peri-operative nutritional
support reduced postoperative complications
(wound complications, wound failure, prolonged
hospital stay, ICU days, use of hospital
resources) by about 10, without significant
increase in infectious complications.
3Who will need it?
- Well nourished and mildly malnourished patients
who cannot take oral food for more than one week
post operatively to avoid prolonged starvation. - Severely malnourished patients undergoing general
surgery procedures. - All critically ill patients (Sepsis patients,
Multiple Injury patients Burn patients, etc). - Patients whom you predict cannot use their gut
for prolonged period of time (Short gut syndrome,
EC fistula, etc).
4When to Start?
- Preoperatively in severely malnourished patient
undergoing a major surgical operation. - Immediately postoperatively in severely
malnourished patients. - Immediately after major trauma, sepsis, major
burns. - Normal or mildly malnourished patient who is
unable to eat on his own by 7 days after surgery.
5Metabolism
- Nutritional implications in surgical diseases are
numerous and include anorexia, sodium and fluid
retention, accelerated gluconeogenesis,
hyperglycemia, insulin resistance, and lipid
intolerance. - In reviewing body nutrient metabolism, one must
consider body energy stores.
6Metabolism
- Triglyceride storage in the typical male consists
of 140,000 calories. - Muscle contains 24,000 calories as protein, 2000
calories as glycogen, 3000 calories as
triglyceride. - Liver contains 300 cal as glucose in glycogen
form, 500 cal as triglyceride. - Unstressed starvation uses adipose stores.
7Metabolism (unstressed)
- During the first 48-72 hrs increased use of fat
stores, and most tissues except RBCs, WBCs, and
renal medulla oxidize lipid stores. - Brain has an obligate glucose requirement, over
3-5 days uses fatty acids for energy.
8Assessment of Nutritional Status
- Weight loss is a significant indicator
- More than 10 unintentional loss in 6 month
period. - 5 loss in 1 month.
- Anorexia, persistent nausea, vomiting, diarrhea,
malaise. - Loss of subcutaneous fat, muscle wasting, edema,
ascites.
9Evaluation of Nutritional Status(Difficult)
- Weight loss
- Serum markers
- Albumin level T1/2 21 d
- Transferrin T1/2 8 d
- Prealbumin level T1/2 2-3 d
- Immune competence (delayed hypersensitivity
reaction, total lymphocyte count)
10Assessment
- Signs of specific nutritional deficiencies.
- Skin rash
- Pallor
- Cheilosis
- Glossitis
- Gingival lesions, hepatomegaly, neuropathy,
dementia.
11Evaluation of Body Composition
- Ideal body weight (IBW)
- Men 106lb 6lb for each inch over 5 feet
- Women 100lb 5lb for each inch over 5 ft.
- IBW depends on patient age, body habitus.
- Other measurements include triceps skin fold, arm
circumference.
12Body Composition
- BMI characterizes degree of obesity.
- weight(kg)/total body surface area.
- BMI over 40 or over 35 with co-morbid conditions
are considered candidates for surgical treatment. - Severe obesity is associated with significant
increase in morbidity and mortality.
13Laboratory Markers
- Serum proteins
- Albumin half life 20 days
- Transferrin half life 8.5 days
- Prealbumin half life 1.3 days
- Retinol binding protein 0.4 days
- Severe hypoalbuminemia lt2 poor outcomes
- Albumin not a good short term marker
14Energy Expenditure
- Can be measured by the respiratory quotient.
- RQ CO2 production(VCO2)/O2 consumption (VO2).
- Indirect calorimetry allows for gas analysis and
calculation of RQ.
15RQ
- RQ of 1.0 predominant glucose utilization.
- RQ of 0.7 and 0.8 consistent with fat and protein
utilization. - RQ higher than 1.0 suggests over feeding and
lipogenesis.
16Nutritional Requirements
- Total energy requirements.
- Total protein requirements.
- The relative distribution of calories between
carbohydrates, fats, and protein.
17Energy Requirements
- Harris-Benedict equation estimates BEE at rest.
- Men 66 (13.7x weight) (5x height) (6.8 x
age). - Women 65 (9.6 x weight) (1.7 x height) (4.7
x age) - Most require 25-35 kcal/kg/day.
- Stress increases these values.
18Stress
- Low stress 1.2 x BEE
- Moderate stress 1.2-1.3 x BEE
- Severe stress 1.3-1.5 x BEE
- Major burn injury 1.5-2.0 x BEE
- Requirements are increased by fever, infection,
activity, burns, head injury, trauma, renal
failure, surgery. - Decreased by sedation, paralysis, B blocker
19Stress Factors
20Carbohydrate (30-60 of Total)
- Serve as main energy source for cellular
metabolism when energy is rapidly required
following stress. Each gram releases 4 kcal. - Also important in membranes as glycoproteins,
glycolipids, carbon backbone of essential amino
acids.
21Carbohydrate (30-60 of Total)
- Glucose, galactose, fructose main six carbon
sugars. - CHO are stored as glycogen in liver (40), muscle
(60), cardiac muscle. - Stores depleted in 48hrs (starve), 24 hrs
(stress).
22Carbohydrate
- Liver glycogen is only source of free glucose
available systemically from carbohydrate stores. - Muscle glycogen is used for muscle itself, and
not available for other tissues. Does not have
G-6-P to do this.
23Protein
- As opposed to CHO, protein absorption in
intestine is incomplete, leading to a mixture of
free AA and oligopeptides. - A major portion of protein digestion products are
absorbed by luminal cells as small peptides,
subsequently digested to yield free amino acids
inside the cell.
24Protein
- Essential components of all living cells,
involved in virtually all bodily functions. - Serve as enzymes, hormones, neurotransmitters,
immunoglobulins, transport proteins. - Total protein in a healthy male is 15-18 of body
weight. - Protein is not stored, should all be considered
functional.
25Protein
- Obligatory turnover rate of proteins.
- 2.5 of total body protein is broken down and
re-synthesized every 24hrs. - Half of this is daily digestive process,
maintenance of immune function, muscle protein
synthesis, hemoglobin turnover - Protein yields 3.5 kcal per gram.
26Protein Requirements
- Most healthy individuals require 0.8-1.0 g
protein/kg/day. - Mild stress 1-1.2 g/kg/day.
- Moderate stress 1.3-1.5 g/kg/day.
- Severe stress 1.5-2.5 g/kg/day.
- Renal failure (more)
- Hepatic encephalopathy (less)
27Nitrogen Balance
- A crude measurement of protein consumption.
- Difference between net nitrogen intake and
excretion. - Positive balance indicates more protein ingested
than excreted. - Negative balance is catabolism.
- Protein excretion in urine nitrogen x 6.25g.
28Amino Acids
- Most AA metabolized by liver
- Branched chain AA are metabolized by muscle.
- Patients require at least 20 of their protein
intake as essential AA. - Glutamine is most abundant AA in blood, a
principle food for enterocytes, mucosal
integrity, macrophage and lymphocyte
proliferation.
29Lipids
- Where CHO and protein are fairly soluble, lipids
are characterized by poor solubility in aqueous
solutions, good in organic solvents. So
digestion presents some unique problems. - Role of lipids include energy source, cell
membrane structure, lubricant for body surfaces,
joints, and mucous membranes.
30Lipids
- Should provide 25-40 of total calories.
- Fatty acids a major source of fuel for heart,
liver, skeletal muscle. - Liver oxidation of fatty acids yields ketones
which are used by the heart, brain, muscle during
starvation. - During the fed state, insulin stimulates
lipogenesis and fat storage, inhibits lipolysis
in adipocytes.
31Triglycerides
- Long Chain must be emulsified by bile salts to
for micelles. - Must be hydrolyzed by pancreatic lipase in the
proximal small bowel for absorption to occur. - Medium Chain absorbed directly by enterocytes,
thru portal system to liver. - Readily absorbed despite severe deficiencies in
pancreatic function. Less steatorrhea.
32Essential Fatty Acids
- During parenteral nutrition, at least 3-5 of
total calories as fat is necessary to prevent
essential fatty acid deficiency. - Linoleic and Linolenic acid are precursors to
prostaglandins and eicosanoids. - Deficiencies result in dermatitis,ecchymosis,
alopecia, anemia, edema, thrombo, respiratory
distress. - Manifestations occur in 4-6 weeks.
33Vitamins
- Deficiencies can occur in severely malnourished
patients, chronic nutritional support. - Impaired wound healing can be a direct result of
deficiencies in Vitamin A, C, and zinc.
34Deficiencies
- Vitamin A- Wound healing
- Vitamin D- Rickets, osteomalacia
- Vitamin E- Anemia, ataxia, nystagmus, edema,
myopathy. - Vitamin C- Wound healing
- Thiamine- Encephalopathy
- B6- neuropathy
35Stress
- The same events as starvation.
- Much more accentuated tissue protein breakdown in
order to - Supply increased demands of energy
- Supply building blocks for acute phase reactant
proteins by the liver. - This accentuated protein breakdown is stimulated
by - Increased steroid production
- Cytokines associated with acute stress response
- Nitrogen loss
- 5-8 gm/d normally
- 2-4 gm/d after several days of unstressed
starvation - 30-50 gm/d under severe stress (multiple trauma,
sepsis, burns)
36Critical Illness
- Metabolic rate is increased
- While patients are in negative nitrogen balance,
protein synthesis is active centrally - Fat not as available as energetic substrate
- Cortisol and catecholamines block lipolysis and
oxidation of fatty acids to ketone bodies
37Metabolism (stressed)
- Hypermetabolism associated with major catabolic
illness, trauma, major surgery is a significant
change. - Increase in ACTH, epinephrine, glucagon, cortisol
production. - As in unstressed, glycogen is used up in
12-24hrs. - But gluconeogenesis continues at accelerated rate.
38Metabolism (stressed)
- Muscle protein, in addition to providing a source
for gluconeogenesis, serves as a substrate for
acute phase protein synthesis by providing
necessary AA. - Liver reprioritizes to produce acute phase
proteins rather than visceral proteins. - Increased glutamine and alanine released from
muscle for gut and liver respectively. - Hyperglycemia common because of gluconeogenesis
and insulin resistance.
39Alterations During Stress
- CHO ACTH, cortisol, catecholamines, glucagon.
- Hyperglycemia frequently present during stress
secondary to relatively low insulin level and
peripheral insulin resistance. - Insulin inhibited by catecholamines, sympathetic
nervous system, somatostatin. - Catecholamines and cortisol contribute to insulin
resistance peripherally.
40Alterations During Stress
- Liver glycogenolysis, gluconeogenesis stimulated
by catecholamines, cortisol, glucagon. - The glucose produced is essential for RBCs, WBCs,
renal medulla, neural tissue, wound tissue. - Protein synthesis increases during stress
- Net proteolysis and negative nitrogen balance are
characteristic of severe stress.
41Alterations During Stress
- Alanine release from peripheral tissue increases
as it is the major source of AA substrate for
gluconeogenesis in the liver. - During severe sepsis, muscle protein loss may
occur at 240 g protein per day. - IL-1 may play a role in stimulating proteolysis
in this setting. - Lipids During severe stress, lipolysis is
stimulated by increased cortisol, catecholamines,
glucagon, GH, ACTH, sympathetic activity.
42Hormonal Response to Injury
- Insulin
- Glucagon
- Catecholamines
- Cortisol
- ADH
- Renin
43Protein Synthesis in Critical IllnessReprioritiza
tion
- Albumin
- Retinol binding protein
- Transferrin
- Acute phase proteins
- Immune proteins
44Nutritional Supplementation
- Benefits high risk patients such as severely
malnourished, critically ill, burns, severe
trauma. - Delayed oral intake 7-10 days.
- Enteral route is indicated in all patients with
an intact, functioning GI tract. - Prevents intestinal atrophy, gut immune function,
inhibition of stress induced increase in
intestinal permeability.
45Nutritional Supplementation
- Oro-enteric, naso-enteric, gastrostomy,
jejunostomy. - Small bore NG tubes can be use for short period
of time. - Gastrostomy and jejunostomy for long term.
- Complications in placement, organ injury,
aspiration, malfunction, leaks, sinusitis,
erosion..
46Supplementation
- Relative contraindications to enteral feeding
- Mesenteric ischemia
- Bowel obstruction
- Sepsis
- Pancreatitis
- Fistula
- SBS
47Role of Gut in Critical Illness
- Mice fed TPN
- Reduced GALT T- and B-Cells
- Reduced IgA production in GI AND Respiratory
Tracts - Reduced immunity to respiratory tract infectious
challenges - viral and bacterial - Enteral feeding
- Restored GALT cell lines
- Restores immune function
- Restores ability to resist URI challenges
- Ann Surg, 1997
48Enteral Feeding
- The most frequently cited advantage of enteral
feeds is relative decreased infection rate in
critically ill patients. - Glutamine- mucosal integrity, immune function.
Levels fall significantly during severe stress
and sepsis. - Arginine- improves N balance, T-cell
responsiveness, reduces infection complications. - Omega-3 fatty acids- precursors for eicosanoids,
immunoregulatory role possible.
49Over Feeding
- Detected if respiratory quotient (RQ) is above 1
(determined by the metabolic cart). That means
that there is lipogenesis. - Has adverse effects
- Respiratory failure due to excess CO2 production
during lipogenesis. - Hepatic failure due to excess fatty liver
infiltration and cholestasis. - Overfeeding has to be completely avoided as it is
harmful to the patient.
50Parenteral Feeds
- TPN- indicated when GI tract is unavailable or
nonfunctional. - Via Central catheter due to hyperosmolarity of
the solutions. - Complications related to catheters frequent.
- Severe metabolic complications can occur.
- Hyperglycemia, hypoNa, hypoK, hypoMg, hypoP,
hypereverything.
51Parenteral Feeds
- Refeeding Syndrome- may develop rapidly in
severely malnourished patients started on TPN. - Most frequently associated with admin of high
calorie supplements, supplements with high
carbohydrates.
52TPN Orders
- Calculate VOLUME requirements/24h.
- Determine PROTIEN requirements g/kg/d.
- Calculate daily CALORIES kcal/kg/d.
- Determine to be given as protein, CHO, fats.
- Add ELECTROLYTES, TRACE ELEMENTS.
- Co-administer Lipids to prevent fatty acid
deficiency. - Lipids give more calories in less volume
- A 10 lipid sol. 1.1kcal/ml, 20 is 2.0 kcal/ml.
53Take Home Messages
- Nutritional supplementation reduces the risk of
complications if given to severely malnourished
patients undergoing major surgical procedures and
in patients with severe sepsis, trauma and burns
(by 10) but does not impact the mortality. - Nutritional supplementation is not indicated in
healthy subjects postoperatively until one week
postoperatively or in patients who are predicted
not to be not able to eat to avoid prolonged
starvation.
54Take Home Messages
- Enteral feeding must be the first choice always
for nutritional supplementation. - Parenteral nutrition is an important tool in the
armamentarium, however it has a lot of inherited
problems. Only used when enteral feeding cannot
be done. - Overfeeding is very harmful for patients and must
be avoided and looked for.