1. Fluids and Electrolytes

2. Objectives To discuss fluid and electrolyte changes:
How to assess fluid patterns and changes in electrolytes
To focus on hypo and hypernatremia, hypo and hyperkalemia, hypo and hypercalcemia and hypophosphatemia

3. Most common fluid disorder deficits
Excessive loss / inadequate intake
G.I. losses from vomiting, nasogastric suction, diarrhea, and fistula drainage
Fluid sequestration
Pre and postoperative deficits
NPO
Bowel prep
Vomiting, NGT losses
Ileus, obstruction
Peritonitis

4. Gastrointestinal fluid daily output

5. How to assess and manage fluid status
IVFV
5%, plasma volume = 3.5L
70 kg male
Plasma volume
Total Blood Volume
IVBV
5.6 L
ECF = 14 L
ICF = 28 L
Is the patient in need of fluid? How much?
If you know the amount of losses – replace them and deliver rapidly
Example: hypotensive patient given a 2 liter bolus as initial treatment
If not: replace losses as they occur
Fluid given based on composition, tonicity of fluid lost
Example: ileostomy losses replaced volume per volume every 4 hrs with lactated Ringer’s solution (better with sterofundin)
2 liters
8.4L = interstitial fluid
Resurreccion R. PCS Committee on Critical Care. Handbook of Critical Care and Surgical Nutrition First Ed, Philippine College of Surgeons

6. How to assess and manage fluid status
Is the patient in need of fluid? How much?
If you know the amount of losses – replace them and deliver rapidly
Example: hypotensive patient given a 2 liter bolus as initial treatment
If not: replace losses as they occur
Fluid given based on composition, tonicity of fluid lost
Example: ileostomy losses replaced volume per volume every 4 hrs with lactated Ringer’s solution (better with sterofundin)
Total Blood Volume
Plasma volume
RESUSCITATION
2 liters
IVBV
5.6 L
REPLACEMENT
ICF = 28 L
IVFV
5%, plasma volume = 3.5L
ECF = 14 L
8.4L = interstitial fluid
Resurreccion R. PCS Committee on Critical Care. Handbook of Critical Care and Surgical Nutrition First Ed, Philippine College of Surgeons
70 kg male

7. How to assess and manage fluid status
Maintenance requirements: after resuscitation and replacement
Based on normal physiologic requirements
Get the accurate weight
Get the 5% plasma volume (70 kg x 5% = 3.5 liters)
Get 1/2 of the plasma volume = 3.5 liters divided by ½ = 1.75 liters
Add the “insensible loss” of 70 kg x 0.05 ml/kg/day = liters = liters/day or 2 liters/day
Similar to daily fluid requirement = kg BW x 30 cc/kg/day or 70 kg x 30 ml/kg/day = 2.1 liters/day or 2 liters/day
MAINTENANCE

8. Fluid overload and mortality
Overload criteria: > 10% weight gain from pre-admission weight
Weight gain and mortality:
5% weight gain -> 10% mortality
15% weight gain -> 20% mortality
32% weight gain -> 100% mortality
Fluid overload criterion = >10% weight gain from pre-admission weight
The information on perioperative volume delivery is important because of the following data:
5% weight gain = 10% mortality
15% weight gain = 20% mortality
32% weight gain = 100% mortality
REFERENCE: Lowell JA, Schifferdecker C, Driscoll DF et al. Postoperative fluid overload: Not a benign problem. Crit Care Med 1990; 18:
Lowell JA, Schifferdecker C, Driscoll DF et al. Postoperative fluid overload: Not a benign problem. Crit Care Med 1990; 18:

9. The effect of fluid overload
These data from the anesthesiologists’ study showed the impact of fluid overload on complications of morbidity and mortality. In the standard or usual management group there was significant increase of major and minor complications, tissue healing complications, cardiopulmonary complications and deaths.
REFERENCE: Brandstrup B et al. Effects of intravenous fluid restriction on postoperative complications: comparison of two perioperative fluid regimens: a randomized assessor-blinded multi-center trial. Annals of Surgery 2003; 238:

10. In the resuscitation phase what to do?
BLS and ATLS protocols
Not ABC, but CAB (=establish perfusion first to reach the microcirculation then oxygenation and the rest follows)
Ventilation: bag > mask > intubate
Establish intravenous line when possible (large bore needle) > central line is ideal if possible
Crystalloids: first line > give as much as 2-3 liters fast (500 ml bolus every minutes)
Colloids: given as blood volume deficits
Medications: inotropes
Blood: Hb? Hct? what level?
To provide correct and adequate resuscitation one needs both basic and advanced life support training. These are some of the updates:
Circulation needs to be established first hence the CAB steps. (Circulation, Airway, Breathing)
Next ventilation is priority and if there is a need to intubate it has to be done.
A venous line should be established with colloids as the first fluids of choice
Reference: Aquino ML, Resurreccion R. PCS Committee on Critical Care. Handbook of Critical Care and Surgical Nutrition First Ed, Philippine College of Surgeons
Aquino ML, Resurreccion R. PCS Committee on Critical Care. Handbook of Critical Care and Surgical Nutrition First Ed, Philippine College of Surgeons

11. Plasma and crystalloids given*
Balanced electrolyte solution
Ringer’s Lactate
Sterofundin
The closest crystalloid to the composition of plasma is “Sterofundin”. It is called a balanced electrolyte solution and except for its “zero” calcium is the most ideal for fluid replacement and maintenance. It has no dextrose which will make the solution isotonic.
When you add dextrose to all of the above > HYPO-OSMOLAR

12. What happens when you increase blood volume by 1 liter?
IVFV
ECFV
ICFV
20%
40%
9.4L D5W 6L
14.4L
36L
5L 0.9%
NaCl
16L
1L 6% HES
Capillary
membrane
Cell membrane
Zander R. Fluid management.2nd ed., Mainz, Germany.
Intracerebral edema

13. Specific electrolyte management

14. Hyponatremia <135 Determine volume status Hypovolemia
Principles of Surgery 10th ed; G. Tom Shires III
Hypovolemia
Give 0.9 NaCl solution
Causes:
GI losses
Renal losses
Primary renal disease
Euvolemia
Correct using hypertonic 3% NaCl (513 mEq/L)
Normovolemia
Water restriction (0.5 – 1.5 liter per day) (evidence of peripheral edema, ascites, pleural effusion
Avoid diuretics to lessen urinary Na+ losses
Correct hyperglycemia
Monitor and decrease increased plasma lipids or proteins
SIDH
Calculate for total sodium deficit in mEq = (135 – serum Na) x 0.6 x kg body weight
Ex: ( ) x 0.6 x 70kg = 5 x 0.6 x 70 = 210 mEq to add
Rate of correction should follow the following:
Risk of demyelinating encephalopathy with rapid correction of hyponatremia
Maximum rate of correction is 0.5 mEq/L/hr
Resurreccion R. PCS Committee on Critical Care. Handbook of Critical Care and Surgical Nutrition First Ed, Philippine College of Surgeons

15. Hypernatremia > 140 Determine volume status Hypovolemia
Principles of Surgery 10th ed; G. Tom Shires III
Hypovolemia
Non-renal water losses
Skin and GI losses
Renal water losses as in renal tubule disease
Osmotic diuresis
Diabetes insipidus
Adrenal failure
Euvolemia
Non-renal water losses
Skin and GI losses
Renal water losses as in renal tubule disease
Osmotic diuresis
Diabetes insipidus
Adrenal failure
Hypervolemia
Iatrogenic sodium administration
Mineralocorticoid excess
Aldosteronism
Cushing’s disease
Congenital adrenal hyperplasia
Treatment for hypernatremia, regardless of its cause, is free water replacement.
For a 70 kg man with hypernatremia of 10, needs 3 liters of free water replacement

16. Hypernatremia correction
How to give free water replacement
H2O deficit (liters) = 0.60 x weight (kg) x (serum Na – 140) ÷ 140
Water deficit (L) = [0.6 x 70 kg x ( )] / 140 = 3 liters
One half of the water deficit should be given over the first 24 hours, with the remainder given over the next 24 to 48 hours
3 liters – 24 hrs = 1.5 liters in 24 hours
The rest in the next 24 to 48 hours (e.g. 1.5 liters in 48 hours or 31 ml/hr for 48 hours)
If diabetes insipidus:
give DDAVP (Desmopressin), an ADH analogue
Minirin 100 mcg tablet every 12 hrs
DDAVP nasal spray 1μg/spray, 2-4 μg BID
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

17. Hypokalemia < 3 Serum potassium less than 3 mEq/L
Common problem in the surgical patient
Caveats
Measured extracellular potassium represents only a small proportion of total body potassium
Small changes in serum concentrations correspond to significant alterations in total body potassium
No reliable equation to compute for K deficit
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

18. Hypokalemia correction
Estimate of K+ deficit:
If serum K+: 3.0 to 4.0 mEq/L → total deficit: 100 to 200 mEq
If serum K+: 2.0 to 3.0 mEq/L → total deficit: 200 to 400 mEq
Management:
Intravenous:
Maximum rate of KCl infusion 10 mEq/hr (in the floors) to 20 mEq/hour (ICU under cardiac monitor)
Use central vein for KCl incorporation >40 mEq/L
Oral: Kalium durule 0.75 mg (10mEq), 3 durules q 4 hrs
NGT: do not crush Kalium! Use oral KCl solution (1mEq/cc)
Total max dose: 3 mEq/kg/day
If persistently low K+ despite correction, check Mg levels for concurrent hypomagnesemia
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

19. Hyperkalemia > 5.5 Serum K+ greater than 5.5 mEq/L Management:
Cardiac monitoring indicated
Renal excretion can be enhanced by the administration of loop diuretics
K+ binding resins: ex. Kalimate 5g/sachet 3 sachets in 1/2 glass of water BID
Hemodialysis in renal failure
Immediate treatment required if:
K+ > 6.0 mmol/L with ECG changes or
K+ > 6.5 mmol/L with or without ECG changes
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

20. Hyperkalemia correction
Management
Calcium gluconate 10% soln, 10mL IV over 2 to 5 minutes: to decrease myocardial excitability. Does not decrease K levels
NaHCO3 44 to 132 mEq (1 to 3 amps of 7.5%) IV over 5 min, given after calcium in a separate line, repeat in 10 to 15 minutes, ff by infusion of 2 to 3 amps in D5W titrated over 2 to 4 hours
Insulin 10 to 20 U regular in D10W 500 mL over 1 hour, or 10 U IV push with 1 amp 50% glucose (25 gm) over 5 mins.
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

21. Hypocalcemia < 2.2 Serum Ca < 2.2 mmol/L
Artifact of hypoalbuminemia: serum calcium predominantly bound to albumin.
For every 1 g /L decrease in albumin, serum Ca decreases by mmol/L.
Symptoms: Chvostek’s sign, Trousseau’s sign
Management:
Calcium gluconate 10% soln, 10 – 20 mL IV bolus over 10 to 15 minutes. Followed by mL ampoules of 10% calcium gluconate in 1L D5W
Maintenance: Calcium carbonate 1-2g P.O. TID with Vitamin D3 (Calcitriol; brand name: Rolcaltrol) 0.25 mcg capsule/day
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

22. Hypercalcemia > 3 Serum Ca > 3.0 mmol/L Causes: Management:
Hyperparathyroidism
Bone metastases (breast, lung, thyroid, colon, multiple myeloma)
Vitamin D intoxication
Management:
Hydration with normal saline
Diuretics (except thiazide diuretics)
Chronic therapy for:
Bone metastases: biphosphonate therapy
Paresthesias
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

23. Hypophosphatemia < 2.5
Serum phosphate < 2.5mg/dl
Normal levels: mg/dl or mmol/L
Classified as
Moderate: 0.32 – 0.65 mmol/L
Severe: < 0.32 mmol/L
Causes
Transcellular shift (Refeeding syndrome; Phil incidence = 9%)
Diminished intake (long-term TPN, alcoholism)
Renal replacement therapy (deficiency of trace elements)
Stanga R. Refeeding syndrome in ESPEN basic clinical nutrition manual.
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.
Mustofa N. Refeeding syndrome. PhilsPEN online j paren ent nutr. POJ_0097.html

24. Hypophosphatemia Manifestations:
Muscle dysfunction: respiratory failure, myocardial dysfunction, skeletal muscle weakness, rhabdomyolysis
Altered mental status, seizures, encephalopathy
Arrhythmia: ventricular tachycardia, supraventricular tachycardia
Hemolysis
Jeejeebhoy. Malnutrition,, starvation and Refeeding Syndrome.
Stanga R. Refeeding syndrome in ESPEN basic clinical nutrition manual.
Resurreccion R. Fluids, electrolytes and acid base management in Handbook of Surgical Critical Care and Surgical Nutrition 1st ed. PCS.

25. Thank You