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B6. Gastrointestinal Monitoring
1. Gastrointestinal circulation / oxygen dynamics
a. Tonometry (B5)
b. Imaging (intravital video-microscopy – B5)
2. Endoscopy, etc. (Radiology, Internal Medicine)
Ulcers, GI bleed, Intestinal motility, Diarrhea – Obstipation (Internal Medicine)
B6. Gastrointestinal Monitoring – Monitoring the GI Tract
2. Monitoring the nutrition state
a. Feeding
b. Nasogastric tubes
c. Solutions, possibilities
d. GI preparation - investigations, operations
Nutrition
Adequate nutrition is indispensable for the normal activity of the organism
Malnutrition results in higher frequency of complications
15-60%of patients is malnourished at admission
Serious protein-energy malnutrition (PEM)
a. Marasmus
b. Kwashiorkor
c. Marasmic Kwashiorkor
Nutritional assessment: synthesis of subjective and objective data
Anamnesis
Anamnesis: diarrhoea, vomiting, weight loss, physical disability, fatigue
Weight loss :
- 10-15%
mild
- 20-25%
moderate
Increased
- 30-35%
severe
risk
> 40%
life threatening
Clinical assessment: edema, delayed wound healing, reduced ventilatory capacity, reduced
immunity, increased risk of infection
Anthropometry
(a) Lange skinfold caliper used for assessing thickness of subcutaneous fat. (b) Illustration of
an example of skinfold measurement, triceps skinfold taken on the midline posterior surface
of the arm over the triceps muscle.
Shoulde
r
Tricep
skinfol
s
d
Lang
calipe
e
r
(a
)
(b
)
-
Body Mass Index (BMI), a measure of body fat based on height and weight
-
Mid arm circumference
-
Triceps skinfold
♂: skinfold >10 mm; mid arm circumference > 23 cm
♀: skinfold >13 mm; mid arm circumference >22 cm
Malnutrition: values > 60% below standards
Biochemical - Blood Indices
Se- conc.
(g/l)
Deficit
Half life
Reserve
Albumin
30-36
21-30
20 days
4-5 g / bw
(kg)
Transferrin
2,5-3,0
1,5-2,5
8-10 days
5
Prealbumin
0,15-0,3
0,1-0,15
2 days
1
0,026-0,076
?
10-12 hrs
-
Retinol-binding
protein
Indications for Feeding / Nutritional Support
Patients unable to eat or maintain adequate nutritional intake: unconsciousness, dysphagia,
mechanically ventilated patients, operations on pharynx and oral cavity, strictures of upper
GI-tract
Patients who refuse to take aliments: lack of appetite, psychological diseases
Diseases when natural nutrition is contraindicated: acute abdominal diseases (pancreatitis
acuta, ileus, abdominal sepsis), GI operations, serious inflammatory bowel disease, absorption
problems
Methods of Nutritional Support
Enteral
Early enteral nutrition reduce post-operative morbidity
Cheaper, simpler, safer
Reduces mucosal atrophy
More physiologic, improves intestinal function and morphology
Prevents bacterial translocation
Improves clinical outcome
Primary Choice: use GI tract if available!
Nutrients
water
-
electrolites (Na+, K+, Cl-, Ca++, Mg++)
sources of energy (carbohydrates, fat)
source of nitrogen (amino acids)
vitamins
trace elements (Zn, F, I, Co, Cr, Mn, Mo, Cu, Se, Fe)
Parenteral
- Intestinal failure
- GI discontinuity
- Severe malabsorption
Calory Needs
Basic Energy Exchange (BEE): immobilized patient with empty stomach at room temperature
Harris-Benedict equation:
(1 kcal = 4,185 kJ)
BEE (♂) = 66 + (13,7 x W kg) + (5 x H cm) + (6,8 x A years)
BEE (♀) = 65,5 + (9,6 x W kg) + (1,8 x H cm) + (4,7 x A years)
Normal energy requirements: BEE + 10%
CORRECTION FACTORS!
Calorimetry
Santorio Santorio (1561-1636) of Padova in his steelyard balance
In: Ars de Statica Medecina (1614)
Calorimetry
Insulation layer
Constantan
Metal wall
Cooling tubes
Copper
Thermocouple connection
In a gradient layer calorimeter, thermocouples measure the difference in temperature across
the wall. Ventilating system and measurements not shown.
Thermomete
r
Ai
r
T2
Ai
r
Thermomete
r
Insulated
(polyurethane
chamber
)
T1
heat loss
Qa = mca(T2-T1)
Air mass flow rate
temperature change
of the ventilating air
T2
Water outlet
Polyvinilchloride tubes
Thermometer
T1
Water inlet
Thermometer
The water flow calorimeter measures the inlet and outlet water temperature
Feedback
control
Powe
r
sourc
e
A
C
Thermosta
t
Powe
rmete
r
Heate
r
The compensating heater calorimeter requires less heater power when the subject supplies
heat.
Enteral Feeding - Methods
Method
Ratio
Percutaneous Endoscopy Gastrostomy
(PEG)
57,6%
Nasogastric Tube
32,6%
Jejunostomy
5,9%
Other
3,9%
Gastric Intubation
The Nasogastric (NG) Tube
GASTRIC INTUBATION
Indications - rationale for the insertion:
Gavage (put in): feeding, fluids, medications
Decompression: removal of fluids and gas to promote abdominal comfort, reduce risk for
aspiration, and allows surgical wounds to heal without distention usually with low
intermittent suction
Lavage (washing of a cavity): irrigation and removing toxic substances
Compression of esophageal varices
Aspirate GI content for analysis
TYPES OF NG TUBES
Rubber, plastic, silicone, or polyurethane, different size lumens (Fr)
Some have stylets-wire inside to show on x-ray
Radiopaque-impenetrable to x-ray shows as light area on x-ray
Some are weighted, some go into the small intestine
Basic types: short, standard (medium), long
NG – Short Tubes
• Short: Levin and Salem tubes
– Enter nose to the stomach
– Often before or during esophageal or stomach surgery
– Primary use to remove fluid and gas from upper GI tract, obtain specimen, and
short-term feeding or medication (3-4 weeks)
NG Standard
Single lumen, opening at tip and several along the sides
14-18 Fr
Some are red rubber or plastic and these will require being placed in ice for 15-20 min. prior
to insertion
Nasoenteric used for feeding
Can be duodenum or jejunum
Decrease irritation of nose and throat
Cardiac sphincter closes more tightly around tube 6-12 Fr
Weighted, tungsten tips, radiopaque, some have stylet
Takes approx. 24 hrs to pass from the stomach to the small intestine
Some have water activated lubricant
NG Special
• Dobhoff / Entraflo
Made of polyurethane or silicone rubber, 8-12 Fr, tungsten-weighted tip, radiopaque,
stylet
NG Long Tubes
Nasoenteric: from nose to intestine, used for decompression. Removes GI content and gas to
prevent intestinal distention by decompression, postoperative obstruction, postoperative
vomiting, and reduce tension on suture line. Stays in place until peristalsis returns
Miller-Abbott: intestinal decompression, 12-18 Fr, double lumen – one for aspiration the
other is to inflate balloon
Harris: used for suction and irrigation, single lumen connected to Y tubing, 14 or 16 Fr,
mercury-weighted - safety considerations
Cantor: long single-lumen rubber tube, mercury, water or saline instilled to weight, MD
inserts (!)
NG Tube Insertion
NG Tube Insertion
Emergency NG Tube Insertion
Indications
• Threat of aspiration
• Need for lavage
-Contraindications
-Extreme caution in esophageal disease or trauma
-Facial trauma (caution)
-Esophageal obstruction
Emergency NG Tube Insertion
• Advantages
- Tolerated by conscious patients
- Does not interfere with intubation
- Mitigates recurrent gastric distention
- Patient can still talk
●
Disadvantages
- Uncomfortable for patient
- May cause vomiting during
insertion
- Interferes with BVM seal
Emergency NG Tube Insertion
• Complications
- Soft tissue trauma from poor technique
- Endotracheal placement
- Supragastric placement
- Tube obstruction
Equipment needed
- Gastric tube
- Topical anesthetic or lidocaine
- Lubrication
- 30-50 ml syringe
- Stethoscope
- Suction
- Tape
●
Emergency NG Tube Insertion
• Prepare patient
- Head neutral
- Oxygenate
- Suppress pharyngeal reflex with anaesthetic
Lubricate tube
Advance into stomach
● Confirm placement
● Secure in place
●
●
Orogastric Tube
• Same parameters as NG tube
• Advantages
– May use larger tubes
– May lavage more aggressively
– Safe to pass in facial fracture
– Avoids pharynx
●
Disadvantages
- May interfere with visualization
during intubation
●
Complications
- Same as NG
- Patient might bite tube
Orogastric Tube Insertion
• Method
- Neutral or flexed head position
- Introduce tube down midline
- Procedure same as NG
Verify Correct NG Tube Placement
1. Can the patient breath? If the patient has any indicators of respiratory distress (dropping O2
saturation, dyspnea, coughing, cyanosis) – remove the tube!
2. Can the patient talk (a properly placed nasogastric tube bypasses the vocal cords, the
patient should be able to speak)
3. Has the tube coiled (using a penlight and tongue blade, inspect the pharynx. The tube
should be visible as one straight line in the pharynx)
4. Can air be heard (inject 10-20 ml of air with a 60 cc piston syringe while auscultating over
the left upper abdominal quadrant).
5. Is there gastric aspirate (using a 60 cc piston syringe, draw back gastric content).
6. Verification of NG tube placement by x-ray is the most reliable method.
NG Tube Placement
• Gastric contents? Not sure?
What is the pH?
• Using pH strip, check pH: stomach is usually 1 - 5.0
• Small intestine pH: 6.0
• Lung pH: >=7.0
Securing the NG Tube
The NG tube is secured to the nose with tape (B); a tape is placed on the forehead and the NG
tube is taped to it, thereby allowing the tube to be advanced until desired placement is
achieved. (C, D) Secure tubing to the patient's gown with either an elastic band or tape
attached to a safety pin.
Complications of NG Tube Insertion
1.
Accidental tracheal intubation
• Pleural effusion (instillation of feedings/medications)
• Pulmonary hemorrhage (traumatic insertion)
• Pneumothorax
2. Accidental sinus intubation(rare, but has occurred)
3. Esophageal perforation
4. Tube coiling/loops
Gastrostomy and Jejunostomy
Abdominal Stomas
Stoma: surgically created communication between a hollow viscus and the skin
Types: colostomy, ileostomy, urostomy, caecostomy, jejunostomy and gastrostomy
Functionally: end, loop, continent stoma
The First “Gastrostomy”.
Dr. William Beaumont – Father of Gastric Physiology (1785-1853)
„On June 6, 1822 on Mackinac Island, a French-Canadian voyageur named Alexis St. Martin
was shot in the upper left abdomen; the musket wound was "more than the size of the palm of
a man's hand. The contents of the weapon, consisting of powder and duck-shot, entered his
left side from a distance of not more than a yard off.
The charge was directed obliquely forward and inward, literally blowing off the integument
and muscles for a space about the size of a man's hand, carrying away the anterior half of the
6th rib, fracturing the 5th rib, lacerating the lower portion of the lowest lobe of the left lung,
and perforating the diaphragm and the stomach. The whole mass of the discharge together
with fragments of clothing were driven into the muscles and cavity of the chest.
When first seen by Dr. Beaumont about a half hour after the accident, a portion of the lung, as
large as a turkey's egg was found protruding through the external wound. The protruding lung
was lacerated and burnt. Immediately below this was another protrusion, which proved to be a
portion of the stomach, lacerated through all its coats. Through an orifice, large enough to
admit a fore-finger, oozed the remnants of the food he had taken for breakfast. His injuries
were dressed; extensive sloughing commenced, and the wound became considerably enlarged.
Portions of the lung, cartilages, ribs, and of the ensiform process of the sternum came away.
In a year from the time of the accident, the wound, with the exception of a fistulous aperture
of the stomach and side, had completely cicatrized. This aperture was about 2 1/2 inches in
circumference, and through it food and drink constantly extruded unless prevented by a tentcompress and bandage."
[George M. Gould and Walter L. Pyle (Philadelphia, 1896)]
The First “Gastrostomy”
Alexis St. Martin’s wounds description in Dr. Beaumont’s book (Experiments and
Observations on the Gastric Juice and the Physiology of Digestion, 1833)
"This engraving represents the appearance of the aperture with the valve depressed.
A A A Edges of the aperture through the integuments and intercostals, on the inside
and around which is the union of the lacerated edges of the perforated coats of the
stomach with the intercostals and skin.
B
The cavity of the stomach, when the valve is depressed.
C
Valve, depressed within the cavity of the stomach.
E E E E Cicatrice of the original wound."
Gastrostomy and Jejunostomy Tubes
Used to administer food and fluids for < 3-4 weeks
Percutaneous Endoscopic Gastrostomy (PEG)
• Gastrostomy
• Surgically created gastric fistula
Jejunostomy tube
• Surgically created, permanent opening in the jejunum
Percutaneous Endoscopic Gastrostomy (PEG)
Percutaneous Endoscopic Gastronomy (PEG) feeding tube devised by Micheal Gauderer and
Jeffrey Ponsky (1979).
Percutaneous Endoscopic Gastrostomy (PEG)
1. Skin-level external fixation
2. Obturator
3. Proximal anti-reflux, decompression valve
4. Biocompatible, polyurethane tip inserted into the lumen
Rationales for Tube Feeding
•
•
•
•
•
Primary reason is to prevent and treat malnutrition
Provides nutrients when the GI system is unable to ingest adequate nutrients orally
Low-cost, safe, generally well tolerated
Preserves GI integrity and flora
Normal sequence of intestinal/hepatic metabolism
Tube Feeding Formulas
• Blenderized-can be made by patient’s family or obtained in ready to use form
• Commercially prepared polymeric-contain protein, carbohydrates, and fats in a high
molecular weight (Boost Plus, TwoCal HN, Isosource)
• Chemically defined-contain predigested easy-to-absorb nutrients (Osmolite HN,
Isocal)
• Modular products-contain only one major nutrient such as protein (Promote)
• Disease specific-renal failure (Nepro), COPD (Plumocare), high fiber (Jevity,
Ultracal), Glucerna (diabetes), lactose free
Tube Feeding Methods
• Depends on location of the tube, patients tolerance, convenience and cost
– Intermittent bolus
– Intermittent gravity drip
– Continuous infusion
Techniques of Bolus Tube Feeding
• Bolus: delivery consists of infusing 300-400 cc of formula every 4-6 hrs
Techniques of Intermittent Gravity Feeding
Intermittent gravity: feeding bag attached to tube and allow fluid to flow by gravity. Usually
200-400 mL administered over 30 min at designated intervals.
Technique of Continuous Feeding
Infusion pump / continuous
Complications
•
•
•
•
•
•
•
•
•
•
•
•
Regurgitation / aspiration
Tube dislodgment
Tube clogging
Bacterial contamination
Diarrhea or dumping
Excessive gas
Nausea/vomiting
Nasopharyngeal irritation
Hyperglycemia
Dehydration
Fluid volume deficit
Pulmonary complication
Contraindications
• Bowel obstructions low in GI tract
• Hemodynamically unstable (low BP, on high dose pressors, mean arterial pressure <
60-70)
• Intractable diarrhea
• Severe active GI bleeding
• Ischemic or perforated gut
• High output fistula/ostomy
Parenteral Feeding
Can be given by either a peripheral or central line
Absolute indication
Intestinal failure = „reduction in functioning gut mass below the minimal necessary for
adequate digestion and absorption of nutrients” Enterocutaneous fistulae
Relative indications
Moderate or severe malnutrition
Acute pancreatitis
Abdominal sepsis
Prolonged ileus
Major trauma and burns
Severe inflammatory bowel disease
Parenteral Feeding 1.
Hypocaloric feeding
The energy requirement of the organism is only partially covered (endogenous delivery of
fat).
Carbohydrate intake: 2 g/kg. This can be completed with fat-emulsion (concentration: 10%).
N2 -source: 1-1,5 g/kg aminoacids.
Further: electrolites, vitamins, trace elements
The osmolarity of the solutions is not higher than 900 mOsm/l. Thus, it can be administered
into a peripheral vein.
Parenteral Feeding 2.
Isocaloric feeding
The total nutrition requirement of the organism is covered parenterally.
Average energy-intake: 35-40 kcal/kg
N2-source: 1,5-2,0g/kg aminoacids.
Ratio of carbohydrate and fat: 2:1.
These solutions can be administered only via central veins!
Solutions should be administered as continuous infusions, with infusion pump in 12-18 hrs.
Amino Acids 1.
Solutions: 5, 8, 10, 15% solutions
Components: L-aminoacids (Ile, Leu, Lys, Met, Phe, Thr, Trp, Val, Arg, His, Ala, Pro, Cys,
Gly, Gln, Ser, Tyr,). Can be completed with electrolites and xilit.
Indications: parenteral feeding
Contraindications: deficiency of aminoacid metabolism, metabolic acidosis, hyperhydration,
liver and renal insufficiency, hyperglycemic state, shock
Amino Acids 2.
Warning: drugs should not be injected into these solutions! Adequate intake of K+ and
energy source is required for their metabolism. Monitoring of electrolites (PO4-) and pH is
mandatory!
Further advice: in case of liver dysfunction special solutions should be applied which
contain less aromatic aminoacids and Met.
Fat Emulsions 1.
Solutions: 10, 20, 30% infusion solutions
Components: soybean oil, triglicerides of medium size, phospholipides, Na-oleate, glicerine
Indications: energy source in parenteral feeding, intake of essential fatty acids
Fat Emulsions 2.
Contraindications: hypercoagulation, thrombotic states, shock, acidosis, fat embolism,
gravidity, deficiency of fat-metabolism, insufficiency of liver, early stage of postagressionsyndrome
Warning: assessment of triglycerid, glucose, pH and electrolyte level is required. Parallel
intake of carbohydrates and amino acids helps the metabolism.
Complications of Parenteralis Feeding
- Cannulation
- Infusion
- Metabolism
Postagression Syndrome
- Harmful effects may lead to endocrine stress reaction
- The goal is rapid and persistent energy supply and enhancement of immunological
protective mechanisms
- Catabolic processes dominate
- Glyconeogenesis, lipolysis, increased protein catabolism
- Negative nitrogen balance
- Arg, His, Pro, Gln are semi-essential
- Catecholamines, glycocorticoids, glucagon and thyroid hormons are predominant
Phases of Postagression Syndrome
acute phase
- „high tide”
-postagression
damage
aggression
- „ebb tide”
-
insulin
catabolic phase
reparation phase
increase of muscle strength
- replenishment of fat stores
-
phase
anti-insulin
hormons
insulin
anti-insulin
hormons
insulin
anti-insulin
hormons
Enemas (lavement, klyster, klistier, klysma, clisma) and Laxation
Perioperative GI Care
- Preparing the GI-tract before operations and colonoscopy, conservative therapy of ileus
(detensioning before operation, fluids, electrolites, nasogastric tube)
- Rectal examinations
- 4-days diet without vegetable fiber
- Laxatives: X-Prep, supp. glycerini
- Solutions: Yal-Trommsdorff klysma, Rins-Sal, Rins-Ringer