fluid & Electrolyte

1. Fluid and Electrolytes
Dr. Md. Nazmus Sakib
Junior Consultant
Department of Surgery
Email-sakibs23@gmail.com

2. Fluid
Fig: Distribution of total body water in a 70 kg man. DCT- Dense connective
tissue, ECF- Extra cellular fluid, ICF- intracelluar fluid, TCW- Transcellular
fluid.

3. Average daily water balance for a sedentary
adult
Input (ml) Output (ml)
Drink 1500 Urine 1500
Food 750 Faeces 100
Metabolic 350 Lung 400
Skin 600
Total 2600 Total 2600

4. Water requirement for children
• First 10 kg ---- --100 ml/kg/day
• Second 10 kg---- 50 ml/kg/day
• Each subsequent kg---- 20 ml/kg/day
In case of adult average requirement is 30-40 ml/kg/day

5. Interactive session
 Calculate the daily fluid requirement of a 25 kg
weight child.
 Calculate the fluid requirement of a 70 kg male
patient.

7. During prescribing fluid we should keep in mind
• Basal requirement
• Pre existing dehydration and electrolyte loss
• Continuing abnormal loss over and above basal requirement
Commonly used isotonic fluids are
Normal saline (0.9%)
5% dextrose
Hartman’s solution
Dextrose 4% - Saline 0.18%

8. Normal osmolality of ECF is 280-295 mOsm /kg.

9. The nature and volumes of fluids are determined by:
• A careful assessment of the patient including pulse, blood
pressure and central venous pressure, urine output, urine and
serum electrolytes and haematocrit.
• Estimation of losses already incurred and their nature: for
example, vomiting, ileus, diarrhoea.
• Estimation of supplemental fluids likely to be required in view
of anticipated future losses from drains, nasogastric tubes or
abnormal urine or faecal losses.

10. • When an estimate of the volumes required has been made, the
appropriate replacement fluid can be determined from a
consideration of the electrolyte composition of gastrointestinal
secretions.
• A typical daily maintenance fluid regimen would consist of a
combination of 5% dextrose with either Hartmann’s or normal
saline.

11. Hypo/Hypernatraemia
• Normal Na+ level is 135-145 mmol/L
• Hyponatraemia < 135 mmol/L
• Hypernatraemia > 145 mmol/L
• Causes of hyponatraemia
 Inadequate intake
 GI sodium loss- Vomiting, diarrhoea, external fistula
Excessive sweating, burn
Diuretics
SIADH
Third spacing of fluid- bowel obstruction, pancreatitis

12. Clinical features of hyponatraemia
• Fatigue
• Dizziness on standing
• Postural hypotension
• Low JVP
• Lethargy
• Confusion
• Coma

13. • Correction of hyponatraemia= 0.6 x Weight in kg x Deficit
• Identify and correction of cause
• Options for correction
Orally Tab. NaCl 300 mg
Infusion 0.9% NaCl
Infusion 3% NaCl

14. Causes of hypernatraemia
• Excessive administration of Na containing fluid
• Diabetes insipidus
• Impaired renal function
• Primary and secondary hyperaldosteronism
• CCF, cirrhotic liver disease, nephrotic syndrome

15. Clinical feature
• Restlessness
• Thirst
• Irritability
• Hyper reflexia
• Intra cranial haemorrhage

16. Treatment
• Restoration of intravascular volume.
• Replace the ongoing water loss
• Correction of excess Na according to concentration. If the
condition has developed quickly correct it with appropriate
volume of hypotonic fluid rapidly.
• If the condition has developed slowly correct it slowly.

17. Hypokalaemia
• Major intracellular cation.
• Develops when K+ level is below 3.5 mmol/L
• Clinical feature:
– Asymptomatic when mild (3-3.3 mmol/L)
– Muscular weakness
– Tiredness
– Cardiac effect: ventricular ectopic, arrythmia
– Decrease reflex
– Paralytic ileus

18. Hypokalaemia (Cont…)
ECG
 Flattened T wave
 ST depression
 U wave

19. Causes
 Reduced potassium intake
 Vomiting, diarrhoea, bowel obstruction, laxative abuse
 Alkalosis
 Insulin excess,
 Primary and secondary hyper aldosteronism
 Diuretics

20. Treatment
• Identify the cause
• Correction of deficit
• Maintenance of daily requirement
For mild hypokalemia
• Give potassium containing fruits
• Oral correction by Syp. KCl

21. ***Role of ‘40’ for intravenous correction
 Urine output not less than 40 ml/hour
 Not more than 40 mmol added to 1L
 Not faster than 40 mmol/hour

22. Hyperkalaemia
Causes
• Acedosis
• Insulin deficiency
• Severe hyperglycemia
• Hemolysis, rhabdomyolysis
• Renal failure
• Drug-NSAID, ACE inhibitor, spironolactone
• Addisons disease

23. Clinical feature
• Muscle weakness
• Respiratory failure
• Decrease urine output
• Decrease cardiac contractility

24. ECG
• Wide flat P wave
• Prolonged PR interval
• Wide QRS complex
• Tall peaked T wave

25. Treatment
• Stabilize cell membrane potential by IV calcium gluconate
• Shift potassium into cell
– Inhaled β2 agonist (sulbutamol)
– IV glucose and insulin
– IV sodium bicarbonate
Remove potassium from body
 IV frusemide
 Dialysis

26. Thank You