Fluids and electrolyte

1. NUTRITION AND WATER AND
ELECTROLYTE IN SURGICAL
PATIENTS
Dr Uttam Nepal
1st yr Resident
MS ENT-HNS
KIST MCTH

2. Roadmap:
■ Nutrition in surgical patients
■ Types of feeding its indications and its compliations
■ Fluid management in surgical patients
■ Types of different fluids

3. Nutritional Requirement:
■ Protein requirements-
– Avg. healthy adult : approximately 0.8 g/kg body weight
– Physiologically stressed : 1.2 – 2.5 g/kg/day
– protein intake of 6.25 g =1 g of nitrogen
– 15% of normal energy expenditure
– 1 gm of protein = 4 kcal

4. Nutritional requirement
■ Carbohydrate requirements-
– 40-60 % normal energy expenditure
– 400 kcal of CHO/day minimizes protein breakdown, particularly
after adaptation to starvation
– 1 gm of enteral CHO = 4 kcal & 1gm of parenteral CHO = 3.4
kcal/g
■ Lipid requirements -
– 25% to 45% of normal energy expenditure
– 1 gm of lipid = 9 kcal
– essential fatty acid – at least 3% of caloric intake as lipid

8. Metabolic response to trauma and sepsis
■ Increased counter regulatory hormones
■ Increased Energy requirements (up to 40kcal/kg per day)
■ Insulin resistance and glucose intolerance
■ Preferential oxidation of lipids
■ Increased gluconeogenesis and protein catabolism
■ Loss of adaptive ketogenesis
■ Fluid retention and associated hypoalbuminemia

12. NUTRITIONAL ASSESMENT
■ Clinical history
■ Laboratory Techniques :albumin
■ Body Weight and Anthropometry
■ Imaging : Dual energy x ray absorptiometry
■ Measurement of immunological function

13. Indications for Nutrition Support
■ Unspecified severe protein energy malnutrition in adults
BMI < 18.5 kg/m2 or
unintentional loss of weight (≥10%)
with evidence of suboptimal intake resulting in severe loss of subcutaneous fat
and/or severe muscle wasting.
■ Protein-energy malnutrition of moderate and mild degree
BMI < 18.5 kg/m2
unintentional loss of weight (5–9%)
with evidence of
suboptimal intake resulting in moderate loss of subcutaneous fat and /or
moderate/mild muscle wasting

14. Identification of at risk of
malnutrition
■ Have eaten little or nothing for more than five days and/or are
likely to eat little or nothing for the next five days or longer
■ Have increased nutritional needs from causes such as
catabolism, high nutrient losses or poor absorptive capacity

15. Types of feeding
■ Nasogastric
■ Nasoenteric
■ Gastrostomy
– PEG (percutaneous endoscopic gastrostomy)
– Surgical or open gastrostomy
■ Jejunostomy
– PEJ (percutaneous endoscopic jejunostomy)
– Surgical or open jejunostomy
■ Transgastric Jejunostomy
– PEG-J (percutaneous endoscopic gastro-jejunostomy)
– Surgical or open gastro-jejunostomy

16. Criteria to initiate perioperative nutritional support

18. Calculation of calories by TPN
■ For TPN formulated without lipid (two-in-one solution)
– Total kilocalories = 2100 k cal
– Calories from amino acids 105g× 4k/cal= 420 kcal
– Remaining calories 2100 – 420= 1680 kcal
– Then make up the difference with dextrose: 1680kcal/( 3 .4
kcal /g) =494 g dextrose

19. ■ For TPN formulated with lipid (three-in-one solution):
– Total kilocalories = 2100 kcal
– Provide 20% of the total calories as lipid:
– Lipid = 2100 kcal× 0.2 = 420 kcal
– 420kcal / 9 kcal g = 47 g lipid
■ Calories from amino acids: 105g ×4 kcal =420kcal
– Remaining calories: 2100 – 420- 420=1260 kcal
– Then make up the difference with dextrose: 1260/ 3. 4 = 370
g dextrose

21. Risk of Re-feeding syndrome
■ State of very low blood levels of phosphate, potassium and magnesium which
occurs when a patient is fed rapidly after a period of prolonged fast.
■ The intracellular space suddenly expands with the uptake of glucose and other
nutrients, causing a rise in intracellular electrolytes and a corresponding fall
in extracellular electrolytes.
■ Cardiac failure, pulmonary oedema and dysrhythmias, acute circulatory fluid
overload
■ Hypophosphatemia ,hypokalaemia,hypomagnesaemia

22. Types of feeding
■ Oral
■ Enteral
■ Parenteral

23. Oral feeding
 Conscious patient with intact appetite and swallowing function
 Indicator of compromised swallowing function include :
 Neurological impairment (cognitive or oral motor)
 Coughing or Choking with feeds
 Symptoms indicating a possible aspiration associated
 Pathology(recurrent pneumonia)

24. Oral Feeding
■ Delivery of nutrients directly into GIT
■ Advantages
 more physiological
 maintains the integrity of GIT
 reduces translocation of bacteria from GIT
 reduces the levels of proinflammatory cytokines

25. Early initiation of enteral feeding
■ Early (24 to 48 hrs)institution of enteral feed after major
surgery minimizes
 Risk of Undernutrition
 Can abate hyper metabolic response seen after surgery
■ Intake within first week should be atleast 60% to 70% of the total
estimated energy requirement as per assessment

26. Complications of enteral nutrition
■ Tube-related
 Malposition
 Displacement
 Blockage
 Leakage
 Erosion of skin and mucosa
■ Gastrointestinal
 Diarrhea
 Constipation
 Nausea, vomiting
 Abdominal cramps
 Aspiration
 Metabolic/biochemical
 Electrolyte disorders
 Vitamin, mineral, trace
element deficiencies
 Infective
 Exogenous
(handling contaminatio
n)
 Endogenous (patient)

27. Contraindications to enteral feeding
■ Diarrhea refractory to medical management
■ Paralytic ileus or small bowel obstruction
■ Intractable vomiting
■ Severe shock ,hemodynamically instability
■ GI hemorrhage, Severe short bowel
■ Severe GI malabsorption ,
■ Inability to gain access to GI tract

28. Parenteral Nutrition
■ Development of PN in the 1960s
■ A major advance in surgical care
■ Allow nutrition in and survival of patient with nonfunctioning GI system
■ IV infusion of nutrition in Elemental form ,bypassing digestion
■ Long term Hyperosmolar –TPN
■ Short term lower osmolar solution -PPN

29. Parenteral Nutrition
■ Routes of delivery
 Peripheral(PPN-Peripheral parenteral nutrition)
 Short term nutrition upto 2 weeks
 Advantages: avoid complications of central venous
administration
 Disadvantages: limited by development of thrombophlebitis
 Central(TPN-Total parenteral nutrition)
 central vein preferred(subclavian>internal jugular>femoral)

31. Complications of Parenteral Nutrition
■ Related to nutrient deficiency
 Hypoglycaemia/hypocalcae
mia/ hypophosphataemia/
hypomagnesaemia
(refeeding syndrome)
 Chronic deficiency
syndromes (essential fatty
acids, zinc, mineral and
trace elements)
■ Related to overfeeding
 Excess Glucose :
 hyperglycaemia
 hyperosmolar
dehydration
 hepatic steatosis
 increased sympathetic
activity,
 fluid retention
 electrolyte abnormalities

32. Complications of Parenteral Nutrition
 Excess Fat
 Hypercholesterolaemia
Hypertriglyceridaemia,
 Hypersensitivity reactions
 Related to sepsis
 Catheter-related sepsis
■ Related to line
– On insertion:
– Pneumothorax,damage to
adjacent artery, air
embolism, thoracic duct
damage, cardiac perforation
or tamponade, pleural
effusion
– Long-term use: occlusion,
venous thrombosis

33. Nutritional support of the surgical patient
Nutritional support before and after surgery are critical for
increasing the likelihood of positive outcomes.
1. Optimizing preoperative nutrition
2. Safe initiation of postoperative nutrition
3. Gastrointestinal anastomosis
4. Hemodynamic instability/vasopressor infusion

34. Fluids management in
Surgical patients

35. Body Fluids Components
■ Water constitutes approximately 50% to 60% of total body weight
■ The relationship between total body weight and total body water (TBW) is
relatively constant for an individual and is primarily a reflection of body fat
■ Lean tissues such as muscle and solid organs have higher water content than
fat and bone

37. Body fluid Compartments

38. Water balance in body

39. Water Balance of Body

40. Composition of body fluids

41. Water Intake
■ Primary stimulus : thirst
■ Mediated either by increase
in effective osmolality or a
decrease in ECF volume or
blood pressure.
■ Osmoreceptors, located in
the anterolateral
hypothalamus, stimulated
by a rise in tonicity.
■ Average osmotic threshold
for thirst: 295 mosmol/kg.

42. Water Excretion
■ The major stimulus for
AVP secretion is
hypertonicity.
■ Since the major ECF
solutes are Na+ salts,
effective osmolality is
primarily determined by
the plasma Na+
concentration.

43. Water Excretion
■ Obligatory renal water loss
 Normally, about 600 mosmols solutes must be excreted per
day
 Maximal urine osmolality is 1200 mosmol/kg
 Minimum urine output of 500 mL/d is required for neutral
solute balance.
■ The principal determinant of renal water excretion is
arginine vasopressin (AVP; formerly antidiuretic hormone)
■ Polypeptide synthesized in the supraoptic and paraventricular
nuclei of the hypothalamus and secreted by the posterior
pituitary gland.

44. Hypovolemia
ECF volume contracted
A. Extrarenal Na+ loss
1. Gastrointestinal (vomiting,
nasogastric suction, drainage,
fistula, diarrhea)
2. Skin/respiratory (insensible
losses, sweat, burns)
3. Hemorrhage
B. Renal Na+ and water loss
1. Diuretics
2. Osmotic diuresis
3. Hypoaldosteronism
4. Salt-wasting nephropathies
C. Renal water loss
1. Diabetes insipidus (central or
nephrogenic)

45. Hypovolemia
ECF volume normal or expanded
■ A. Decreased cardiac output
1. Myocardial, valvular, or pericardial disease
■ B. Redistribution
1. Hypoalbuminemia (hepatic cirrhosis, nephrotic
syndrome)
2. Capillary leak (acute pancreatitis, ischemic bowel,
rhabdomyolysis)
■ C. Increased venous capacitance
1. Sepsis

46. Clinical Features of Hypovolemia
 History of vomiting, diarrhea, polyuria
 Fatigue, weakness, muscle cramps, thirst.
 Diminished skin turgor ,dry oral mucous membranes
 Hypovolemic shock
- hypotension, tachycardia,
- cyanosis, cold and clammy extremities, oliguria, and altered
mental status.

47. Laboratory findings of Hypovolemia
 Elevated blood urea nitrogen (BUN) and plasma creatinine
concentrations
 BUN:creatinine ratio of 20:1 or higher - prerenal azotemia
 Urine Na+ concentration : <20 mmol/L
 except in acute tubular necrosis , hypovolemia due to vomiting
 Urine osmolality and specific gravity
 >450 mosmol/kg and 1.015, respectively

48. Management of Hypovolemia
 Mild volume contraction can usually be corrected via the oral route.
 More severe hypovolemia requires intravenous therapy.
 Isotonic or normal saline (0.9% NaCl or 154 mmol/L Na+) is the solution
of choice in normonatremic and most hyponatremic individuals
 Patients with significant hemorrhage, anemia, or intravascular volume
depletion may require blood transfusion or colloid-containing solutions
(albumin, dextran).

49. Commonly used solutions

50. CRYSTALLOID COLLOID
Aqueous solution of low molecular weight
electrolyte
Aqueous solution of high molecular weight
substance
Replacement ratio of crystalloid for blood loss
is 3:1
(1/3rd remains in intravascular, 2/3rd remains
in interstitial)
Replacement ratio of colloid is 1:1 (as all
remains in intravascular space)
T 1/2= 15-20 mins T1/2= 3-4 hrs
Cheap Costly
3 types 1. Hypotonic (5% dextrose)
2. Isotonic (NS, RL)
3. Hypertonic (3% NS, 6% NS
Always isotonic
Difference between Colloid and
Crystalloid

51. Goal Directed Fluid Therapy
■ Based on physiologic variables related to CO, oxygen delivery and
administering of fluids and possibly inotropes, vasopressors, vasodilators and
RBC to improve tissue perfusion and clinical outcome
■ Used both in perioperative and critical care settings
■ Survivor values undergoing major surgery
- Cardiac index >4.5L.min/m2
- O2 delivery index ( DO2I) > 600ml/min/m2
- O2 consumption of index > 170 ml/min/m2

52. ■ Questions to ask before prescribing fluid:
1. Is my patient euvolemic, hypovolemic or hypervolemic?
2. Does my patient need IV fluid? Why?
3. How much?
4. What type(s) of fluid does my patient need?

53. Daily requirement: Fluids and
electrolytes
■ Daily Na + requirement : 1-2
mmol/kg
■ Daily K + requirement : 0.5-1
mmol/kg
■ Daily Glucose requirement :
400kcal to prevent ketosis
So, 70 kg adult will require
 2-2.5 litre water
(1000+500+1000 ml)
 70-140 mmol Na +
 35-70 mmol K +
 5% dextrose (3) + 0.9%
NaCl (2)

54. Principles of Fluid management
 Three components –
 Replacement of any fluid deficit,
 Administration of maintenance fluid and
 Replacement of any losses

55. Replacement of Deficit
 Deficit
 number of hours NPO X maintenance fluid requirement
 measurable fluid losses e.g NG suctioning, vomiting, stoma
output
 Eg: 70 kg patient fasting for 8 hours
 Deficit: 8 X 110= 880 ml
 Half given in first hour, one fourth each in next two hour

56. Maintenance Fluids
 Maintenance Fluid Requirements
 4-2-1 Rule
 4ml/kg/hr for the first 10 kg of body weight
 2ml/kg/hr for the second 10 kg of body weight
 1ml/kg/hr for subsequent kg body weight
 Eg: 70 Kg
 Maintenance Fluid: 40+20+50 ml/hr

57. Replacement of losses
 Replacing third space losses
 minimal surgical trauma: 0-2 ml/kg/hr (eg herniorrhaphy)
 moderate surgical trauma: 2-4 ml/kg/hr (eg cholecystectomy)
 severe surgical trauma: 4-6 ml/kg/hr (eg major bowel
resection)
 Blood Loss
 Replace 4 cc of crystalloid solution per cc of blood loss
(crystalloid solutions leave the intravascular space)
 When using blood products or colloids replace blood loss volume
per volume

58. Pre operative Fluid Guidelines

59. Pre operative Fluids Guidelines
 Elective
 Oral clear fluid intake should continue until 2
hours preoperatively
 Longer fasting discouraged
 Crystalloid with K+ supplementation should be
given in the preoperative period.
 Emergency
 Require timely resuscitation guided by rational
physiologic endpoints such as trends in blood
pressure and heart rate, lactate, urine output, and
mixed or central venous O2 saturations.

60. Intraoperative fluids
■ Stress response to surgery causes maximal vasopressin release -
the requirement for maintenance water is low.
■ Need to maintain arterial pressure to counter the effect of
anesthetic agents, and to replace fluid deficits because of fasting
and ongoing losses associated with surgery.
■ Fluid should be an isotonic solution with or without low-dose
dextrose (0.9–1%).

61. Post operative fluids
■ Hyponatremic encephalopathy is a serious but underappreciated
complication of surgery.
■ Avoided by 0.9% sodium chloride (NaCl) postoperatively when
parenteral fluids are needed.
■ May present with neurogenic pulmonary edema- referred to as
Ayus-Arieff syndrome.
■ should be treated with a 2mL/kg bolus of 3% NaCl.

62. Replacement Fluids
■ The fluid used to replace this deficit should be isotonic – such as
0.9% sodium chloride or Ringer lactate/Hartmann’s solution.
■ Hypovolaemia should be corrected with an initial fluid bolus of
10-20ml/kg of an isotonic fluid or colloid, repeated as necessary
as per APLS guideline.
■ In severe blood loss transfusion will be required.

65. References:
■ Schwartz’s Principles Of Surgery
■ Sabiston Textbook Of Surgery 21st edition
■ Bailey & Love 27th edition

66. Thank You!!!