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Under the guidance of : DR. B.SHASHIDHARAN. Professor and Chief Unit-III By, Dr. Henley Punnen Andrews
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Page 1: Fluid Therapy

Under the guidance of: DR. B.SHASHIDHARAN. Professor and Chief Unit-III

By, Dr. Henley Punnen Andrews

Page 2: Fluid Therapy

Water is the most abundant constituent in the body comprising about 50% of the body weight in women and 60% in men

1. INTRACELLULAR COMPARTMENT :

◦ Largest compartment,55 to 75% is the intracellular compartment

◦ ICF– primarily a solution of potassium and organic anions, proteins

2. EXTRACELLULAR COMPARTMENT :

◦ Fluid that is not contained inside a cell comprises the

extracellular compartment ◦ 25 to 45 % of the total body water ◦ ECF – primarily a NaCl and NaHCO3 solution

Page 3: Fluid Therapy

ECF

Circulating Compartment

Intravascular

(Blood Plasma)

Extravascular

(Interstitial Lymph)

Transcellular Fluid Made of CSF, Digestive Juices,

mucus etc

Page 4: Fluid Therapy

Considered in terms of : 1. Internal balance 2. External balance

Internal balance [flux]: ◦ This is the movement of water across the capillaries of

the body and movement of water between interstitial and intracellular fluids.

Some examples: ◦ Diffusional turnover of water in the body’s capillaries is

about 80,000 liters a day. ◦ Lymph flow is about 1 to 25 L/day. ◦ GFR is 180 L/day and majority of this is reabsorbed in

the renal tubules. ◦ Turnover of fluids in the bowel is about 8 to 9 L/day.

Page 5: Fluid Therapy

Name given to the interstitial fluid which enters the lymphatic vessels

Lymphatic capillaries are present in all the tissues except the CNS and bone

FUNCTIONS OF THE LYMPHATIC SYSTEM ◦ Return of protein and fluid from the interstitial space to

the circulation to maintain oncotic pressure gradient across the capillary membrane. Edema will occur if interstitial oncotic pressure is not kept low.

◦ Role in absorption and transport of fat from small intestine.

◦ Immunological role – lymph glands and circulation of immune cells.

Page 6: Fluid Therapy

There are about one million glomeruli in each kidney.

Glomerulus consists of a tightly coiled network of capillaries surrounded by podocytes.

Blood passes through each glomerulus filtering water and metabolic waste through capillary walls by the surrounding podocytes. The net excess in the glomerular capillaries is 180 litres per day and is known as GFR.

Page 7: Fluid Therapy

Fluid in the bowel is considered as part of transcellular compartment.

Around 9 – 10 liters of fluid enters the gut each day.

98% of this fluid is reabsorbed resulting in a fecal water loss of only 200 ml per day.

Reabsorbtion predominantly occurs in the jejunum and ileum with over a liter per day absorbed in the colon.

Page 8: Fluid Therapy

2. EXTERNAL BALANCE ◦ External balance refers to the comparison between

the water input from and the water output to the external environment. ◦ Over any period of time, input equals output and

the organism is in water balance

Page 9: Fluid Therapy

The afferent or sensor mechanisms which sense abnormalities in ECF volume homeostasis include the following

1. Low pressure baroreceptors i. Carotid atria ii. Great veins iii. Cardiac ventricles iv. Pulmonary capillaries

2. High pressure baroreceptors i. Carotid sinus ii. Aortic arch iii. Intrarenal(juxtaglomerular apparatus)

3. CNS osmoreceptors. 4. Intrahepatic receptors.

Exactly what is sensed by these receptors is not

completely defined.

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The term ‘effective circulatory volume’ describes the factors which are sensed by these receptors. Cardiac output Arterial resistance Mean arterial pressure Blood volume Venous capacitance

Page 11: Fluid Therapy

OSMORECEPTORS

◦ Osmoreceptors are specialized cells in the hypothalamus.

◦ Responds to changes in extracellular tonicity.

BARORECEPTORS ◦ Regulation of arterial blood pressure is accomplished by

negative feed back system incorporated in baroreceptors.

◦ Arterial baroreceptors are located in the carotid sinus at

the bifurcation of external and internal carotids and also in the aortic arch.

◦ Carotid sinus is innervated by the sinus nerve, branch of

the glossopharyngeal nerve(9th nerve) which synapses in the brain stem.

Page 12: Fluid Therapy

Aortic arch baroreceptors are innervated by the aortic nerve, combines with vagus nerve and travels to the brain stem.

Aortic arch receptors are more sensitive in detecting hypovolemia while carotid sinus receptors are more sensitive in detecting hypotension.

Hence the carotid sinus receptors are the dominant arterial baroreceptors.

Receptors are sensitive to Steady or mean arterial pressure. Rate of pressure change: Decreasing the pulse

pressure decreases the baroreceptor firing rate.

Page 13: Fluid Therapy

Control of water input – Thirst which is mechanism for adjusting water input via the GIT.

Control of water output – ADH which provides a mechanism for adjusting water output via the kidney.

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1. Molarity – it is the number of moles of solute per 1 liter of solution.

2. Molality – it is the number of moles of solute in 1000gm solvent.

m = moles solute / 1000gm solvent.

1. Normality – it is the gram equivalent of solute in 1 liter of solution.

2. Osmolarity of a solution – is the number of moles of solute per liter of solution.

3. Osmolality of a solution - is the number of osmoles of solute per kg of solvent.

Page 15: Fluid Therapy

PLASMA OSAMOLALITY = GLUCOSE IN MG% BLOOD UREA IN MG% 2 x PLASMA Na+ + + . (275 – 290mOSM/kg) 18 5.9

Page 16: Fluid Therapy

IV fluids supply two things - ◦ fluid volume ◦ electrolytes

Need for IV fluids: ◦ To expand intravascular volume acutely and produce

enough urine volume to excrete solutes. ◦ To correct an underlying imbalance in fluids or electrolytes

lost from urine, skin and gut. ◦ To supply necessary vitamins and minerals. ◦ To satisfy the calorie needs there by decreasing tissue

catabolism.

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Several methods proposed to relate maintenance needs to body weight, these include: ◦ Basal calorie method based on metabolic rate. ◦ Surface area method ◦ Holliday-Segar System based on weight.

The basal calorie method requires a table and

involves most calculations.

The Surface area method also requires a table to determine surface area and ideal knowledge of patients height and weight.

Page 18: Fluid Therapy

The Holliday-Segar System is used most frequently because of the ease with which the formulae can be remembered.

Requirement of fluid of a 10year old boy weighing 32kg using the Holliday-Segar method (10×100) + (10×50) + (12×20)=1740 mL (10×4) + (10×2) + (12×1)=72 mL/hr

Page 19: Fluid Therapy

CRYSTALLOIDS-Clear solutions –fluids- made up of water & electrolyte solutions & small molecules.

◦ ADVANTAGES: Inexpensive. Easy to store with long shelf life. Readily available. Very low incidence of adverse reaction. Effective for use as replacement fluids or maintenance fluids.

◦ DISADVANTAGE: It takes approximately 2-3 x volume of a crystalloid to cause

the same intravascular expansion as a single volume of colloid.

Causes peripheral edema. Dilute plasma proteins.

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CLASSIFICATION: 1) Replacement solutions 2) Maintenance solutions 3) Special Solutions

Replacement solutions: ◦ Used to replace ECF. ◦ Isotonic Solution. ◦ Solutions have Na+ similar to that of ECF. ◦ It is used to replace blood loss; 3 to 4 times the

volume lost must be administered as only 1/3 to ¼ remains intravascular after 1 hour.

◦ Solutions used are Normal Saline and lactated Ringers Solution.

Page 21: Fluid Therapy

◦ Ringers Lactate : Has small amounts of K+ and Lactate. Lactate is metabolized in the liver to bicarbonates and

helps if acidosis is present.

Maintenance Solutions: ◦ Used to provide maintenance fluids. ◦ They are isosmotic when administered and do not

cause haemolysis. ◦ Dextrose 5% has no Na+ so it is distributed

throughout the total body water with each compartment getting fluid in proportion to its contribution to the Total Body Water.

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Special Solutions: ◦ Crystalloid solutions used for special purposes are

grouped together: Hypertonic 3% saline. Half normal saline. 8.4% bicarbonate solution. Potassium Chloride. Mannitol 20%. 25% Dextrose.

Page 23: Fluid Therapy

5% DEXTROSE SOLUTION ◦ Maintenance solution. ◦ Dextrose used is dextrose monohydrate. ◦ pH range is 3.6 – 6.5.

◦ Indications As a caloric nutrition to provide the patient with

carbohydrate calories. As a water supply in hypertonic dehydration cases. Correction of hypernatraemia. To increase blood sugar in cases of hypoglycemia. Hepato-protective. As an emergency fluid to prevent the risk of shock which

occurs due to sudden decrease of blood or plasma volume.

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As a carrier solution for infusion of drugs- Amphotericin B, Noradrenalin, Sodium Nitroprusside, Amiodarone, Propofol.

◦ Contraindications Cerebral edema- Causes reduction of Na+ in plasma and water passes into

the brain where Na+ concentration is higher causing raised ICT.

Ischemic Brain Injury- Elevated blood sugar levels worsens ischemic brain

damage. Glucose is metabolized to lactic acid around the ischemic

area lowering the pH and exacerbating the ischemic injury.

Hyponatraemia- Provides electrolyte free water which worsens the

situation.

Page 25: Fluid Therapy

NORMAL SALINE (0.9% SALINE SOLUTION) ◦ Contains 9g of NaCl per liter of water. ◦ pH is 5.0 ◦ The osmolality is 308mOsm/L.

◦ Potential problems with the use of large amounts of

normal saline are: Hyperchloraemic metabolic acidosis. Development of oedema.

◦ Indications: As replacement fluids in dehydration. Useful for maintaining the daily requirement of salt

and water.

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Hypovolemia. Diabetic ketoacidosis. Vehicle for most drugs. Treatment of Hypercalcaemia. Others- Bowel wash, Peritoneal lavage, to maintain

tissue hydration during bowel exposure, flushing solution for eye surgery.

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HYPERTONIC SALINE SOLUTIONS ◦ Includes 1.8%, 3%, 5%, 7.5% and 10% NaCl Solutions. ◦ Hypertonic saline 3% has an osmolality of 900

mOsm/L. ◦ Fluid shifts and osmolar changes that occur are: Fluids pass from the cells into the extravascular

compartment. The ECF volume is expanded by approx 2.5L after

administering 1 liter of 3% saline. Since Na+ and Cl- cannot freely cross cell membranes,

the ECF becomes slightly hyperosmolar. Decrease in ICF volume may have effects on brain

causing confusion and mental obtundation due to cerebral cellular dehydration and hypertonicity.

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Indications- ◦ In critical care- Hyponatraemic states and diuretic overuse, Excessive

losses of GI secretions, renal disease. ◦ Brain injury- Hypertonic saline resuscitation of patients with

traumatic and non traumatic brain injury may increase survival but neurological outcomes is unknown.

◦ In scleotherapy direct injection is put into a vein. ◦ Intra-amniotic use in midtrimester abortion. ◦ Volume resuscitation in hemorrhagic shock, septic

shock and major burns.

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◦ Advantages; Rapid increase in intravascular volume. Relatively small intravenous fluid volumes. Decreased intracranial pressures. Small volume resuscitation prevents inflammation and

the resulting organ dysfunction.

◦ Hypertonic saline with dextran: Tested in certain studies in trauma population. Approved for use in 14 European countries. More rapid improvement of blood pressure. Improved blood flow to the brain. Decreasing pressure in the injured brain. Decreases the risk of infection and ARDS.

Page 30: Fluid Therapy

HARTMANN’S SOLUTION (SODIUM LACTATE) ◦ Invented by Sydney Ringer, British physiologist. ◦ pH of 6.5 ◦ Contains- Na+ -130-131 mmol/L Cl- -109-111mmol/L HCO3

- -29mmol/L K+ -5mmol/L Ca2+ -2mmol/L ◦ The Bicarbonate ions are present in solution as

lactate and later converted in the liver to bicarbonate.

Page 31: Fluid Therapy

Indications: ◦ Fluid resuscitation after a blood loss- Trauma, surgery or a burn injury. ◦ Used to induce urination in patients with renal

failure. ◦ Ideal maintenance fluid during and after surgery. ◦ Used in treatment of lower GI tract losses like

diarrhea induced hypovolaemia. ◦ In metabolic acidosis, it provides a glucose free

solution and used in correcting acidosis. ◦ In DKA it has the added advantage of supplying

potassium.

Page 32: Fluid Therapy

Contraindication: ◦ Not suitable for maintenance therapy because the

Na+ content is too high and potassium content too low, in view of electrolyte daily requirement. ◦ In hepatic insufficiency, lactated ringers solution

can precipitate lactic acidosis. ◦ In chronic heart failure, there is an associated lactic

acidosis more in myocardial tissues. ◦ In upper GI losses there is metabolic alkalosis and

lactated ringers solution provides bicarbonate which worsens the condition.

Page 33: Fluid Therapy

DEXTROSE SALINE SOLUTION ◦ Contains 0.9% normal saline and 5% dextrose. ◦ Normal saline rapidly corrects any ECF deficit of

both sodium and chloride while dextrose element provides energy. ◦ Distributed mainly in the extracellular compartment

and so does not correct intracellular dehydration. ◦ Since it is distributed in the extracellular

compartment, can be considered for the treatment of hypovolaemic shock.

Page 34: Fluid Therapy

SODIUM BICARBONATE SOLUTION ◦ 8.4% NaHCO3 solution has an osmolality of

2000mOsm/L. (7 times the plasma osmolality) ◦ Properties: Hypertonic- draws water out of cells until the ECF and

ICF tonicities are equal.

Alkalinizing load will increase the ECF HCO3 and cause metabolic alkalosis which in turn causes intracellular movement of K+ and ECF K+ will decrease. Hence used in the emergency treatment of Hyperkalemia.

Recommended for emergency treatment of acute hyponatraemia.

Page 35: Fluid Therapy

HYPERTONIC MANNITOL SOLUTIONS ◦ Mannitol is a six carbon sugar alcohol prepared by the

reduction of dextrose. ◦ Occurs naturally in fruits and vegetables. ◦ Odorless, sweet tasting, white, crystalline powder with a

melting range of 165° - 168°C.

◦ Actions: Intracellular dehydration. Expansion of ECF volume (except brain ECF) Haemodilution. Decreased blood viscosity with improved tissue blood flow. Cardiovascular effects secondary to expanded intravascular

volume( increased cardiac output, hypertension, heart failure, pulmonary edema)

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Cerebral effects: ◦ Mannitol does not cross the blood brain barrier and is

effective in removing fluid from the brain. This is called mannitol osmotherapy.

◦ Mannitol infusions are used to rapidly decrease elevated ICP due to an intracranial SOL.

◦ The affect is rapid in onset but only temporary (as mannitol is excreted) but buys time for urgent definitive therapy.

◦ Repeated doses of mannitol have less effect. Prolonged use decreases the osmotic effect as mannitol molecule eventually crosses into the cerebral interstitium. Rebound intracranial hypertension is a risk.

Page 37: Fluid Therapy

Contraindications ◦ Anuria secondary to renal disease. ◦ Severe dehydration. ◦ Severe pulmonary congestion or pulmonary

oedema.

Mannitol therapy to be stopped if following develop during mannitol therapy: ◦ Progressive Heart failure ◦ Pulmonary congestion ◦ Progressive renal failure or damage.

Page 38: Fluid Therapy

Adverse Effects: ◦ Fluid and electrolyte imbalances. Adequate

monitoring and support is required. ◦ GI-nausea and vomiting. ◦ Cardiovascular-Pulmonary Edema, Congestive Heart

failure. ◦ CNS Effects- dizziness, headache, etc.

Page 39: Fluid Therapy

Colloids are large molecular weight solutions (nominally MW > 30,000 daltons).

These solutes are macormolecular substances made of gelatinous solutions which have particles suspended in solution and do NOT readily cross semi-permeable membranes or form sediments.

Because of their high osmolarities, these are important in capillary fluid dynamics because they are the only constituents which are effective at exerting an osmotic force across the wall of the capillaries.

Page 40: Fluid Therapy

These work well in reducing edema because they draw fluid from the interstitial and intracellular compartments into the vascular compartments.

Initially these fluids stay almost entirely in the intravascular space for a prolonged period of time compared to crystalloids.

Advantages of Colloids: ◦ ↑ plasma volume. ◦ Less peripheral edema. ◦ Smaller volumes for resuscitation. ◦ Intravascular half-life 3-6 hrs .

Page 41: Fluid Therapy

General ◦ Distributed to intravascular compartment only. ◦ Readily available. ◦ Long shelf life. ◦ Inexpensive. ◦ No special storage or infusion requirements. ◦ No special limitations on volume that can be infused. ◦ No interference with blood grouping or cross matching.

Physical Properties ◦ Iso-oncotic with plasma ◦ Isotonic ◦ Low viscosity ◦ Contamination easy to detect.

Page 42: Fluid Therapy

Pharmacokinetic properties ◦ Half life should be 6 to 12 hrs. ◦ Should be metabolized or excreted and not stored

in the body. Toxicity and other adverse effects on body

systems. ◦ No interference with organ function even with

repeated administration. ◦ Non-pyrogenic, non-allerginic and non-antigenic. ◦ Should not cause agglutination or damage blood

cells. ◦ Should not cause acid base disorders or promote

infection.

Page 43: Fluid Therapy

Types: ◦ Natural colloid- Human serum albumin (5%, 25%) ◦ Synthetic colloids- Dextrans Gelatins Starches Hydroxyethyl starch (HES) Pentastarch

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Used for many years as 1st line colloid for volume expansion.

Properties ◦ It is a single polypeptide consisting of 585 amino

acids. ◦ MW is 66,248 D. ◦ Albumin is an intravascular protein and stays within

the intravascular space unless the capillary permeability is abnormal. ◦ Expands volume 5 times its own volume in

30minutes. ◦ Synthesis is increased by thyroxine, insulin or

cortisol.

Page 45: Fluid Therapy

Side effects: ◦ Volume overload. ◦ Fever due to pyrogens in albumin. ◦ Rise in colloid oncotic pressure impairs renal salt

and water excretion. Indications: ◦ Emergency treatment of shock. ◦ Acute management of burns. ◦ Hypoproteinemia.

Page 46: Fluid Therapy

Dextrans are highly branched polysaccharide molecules available for use as artificial colloids.

Synthesised using bacterial enzyme dextran sucrase from the bacterium Leuconostoc mesenteroides grown in a sucrose medium.

Formulations available are- Dextran 40 and Dextran 70.

Properties: ◦ Available as a 10% solution in NS or D5%. ◦ pH-4.5-5.7. ◦ Excretion is through urine, faeces and RE system. ◦ Dextran 40 is the commonly used dextrans and induce a

marked increase in plasma volume.

Page 47: Fluid Therapy

Side effects: ◦ Clotting deficits. Defects in platlet interaction. Dilution of fibrinogen. ◦ Interference with cross matching so the lab must be

informed that dextrans have been used. ◦ Dextrans cause more severe anaphylactic reactions

than the gelatins or the starches. ◦ Renal failure: in patients with pre-existing kidney

disease.

Page 48: Fluid Therapy

Gelatine is the name give to large MW

polydisperse proteins formed from the hydrolysis of collagen.

Obtained from boiling the connective tissues of animals.

Currently used gelatine solutions: ◦ Succinylated fluid gelatins(e.g., Gelofusine) ◦ Modified fluid gelatins(e.g.,Plasmagel) ◦ Urea-cross linked gelatins(e.g.,Haemaccel, Polygeline) ◦ Oxy-poly-gelatins.

Page 49: Fluid Therapy

Indications: ◦ Replacement of intravascular volume.

Advantages ◦ Lower infusion volume as compared to crystalloids. ◦ Cheaper and more readily available than plasma

proteins solutions. ◦ Readily excreted by renal mechanisms. ◦ Long shelf-life, no refrigeration. ◦ No interference with blood cross-matching.

Disadvantages ◦ Higher cost than crystalloids. ◦ Anaphylactoid reactions can occur.

Page 50: Fluid Therapy

These polydisperse colloid solutions are produced from amylopectin(obtained from maize) which is stabilized by hydroxyl-ethylation to prevent rapid hydrolysis by amylase.

Contraindications ◦ Known hypersensitivity to hydroxyethylstarch ◦ Bleeding disorders. ◦ Congestive Heart Failure. ◦ Renal disease with oliguria or anuria.

Page 51: Fluid Therapy

Side-effects: ◦ Hypersensitivity.

◦ Anaphylactic reactions.

◦ Pentastarch has been shown to be embryocidal in

rabbits and mice. ◦ Headache, Diarrhoea, nausea, weakness, temporary

weight gain, insomnia, fatigue, fever, oedema, acne, malaise, dizziness, chestpain, chills, nasal congestion and increased heart rate have also been reported in clinical studies involving pentastarch.

Page 52: Fluid Therapy

Crystalloids need to be administered in volume 3times greater than colloids due to propensity of leakage into the extra vascular space.

Colloids offer the advantage of enhancing oxygen consumption to a greater extent than crystalloids.

Crystalloids are first line fluids for haemodynamically stable patient but colloids are preferred in haemodynamically compromised patients.

Hypovolaemic patients with normal pulmonary function, the use of colloids maintain colloid osmotic pressure and limit the development of pulmonary oedema under elevated hydrostatic pressure.

Page 53: Fluid Therapy

Infection: ◦ Any break in the skin carries a risk of infection. Although

IV insertion is a sterile procedure, skin-dwelling organisms such as Coagulase-negative staphylococcus or Candida albicans may enter through the insertion site around the catheter.

Phlebitis: ◦ Phlebitis is irritation of a vein that is not caused by

infection, but from the mere presence of a foreign body (the IV catheter) or the fluids or medication being given.

Infiltration: ◦ Infiltration occurs when an IV fluid accidentally enters

the surronding tissue rather than the vein. It is characterized by coolness and pallor to the skin as well as local edema.

Page 54: Fluid Therapy

Fluid overload: ◦ This occurs when fluids are given at a higher rate or in a

larger volume than the system can absorb or excrete.

Electrolyte imbalance: ◦ Administering a too-dilute or too-concentrated solution

can disrupt the patient's balance of sodium, potassium, magnesium, and other electrolytes.

Embolism: ◦ A blood clot or other solid mass, as well as an air

bubble, can be delivered into the circulation through an IV and end up blocking a vessel.

Extravasation: ◦ Extravasation is the accidental administration of IV

infused medicinal drugs into the surrounding tissue.

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Sodium imbalances

Definition

Risk factors/ etiology

Clinical manifestation

Laboratory findings

management

Hyponatr -aemia

It is defined as a plasma sodium level below 135 mEq/ L

Kidney diseases Adrenal insufficiency Gastrointestinal losses Use of diuretics (especially with along with low sodium diet) Metabolic acidosis

•Weak rapid pulse •Hypotension •Dizziness •Apprehension and anxiety •Abdominal cramps •Nausea and vomiting •Diarrhea •Coma and convulsion •Cold clammy skin •Finger print impression on the sternum after palpation •Personality change

•Serum sodium less than 135mEq/ L • serum osmolality less than 280mOsm/kg

•Identify the cause and treat *Administration of sodium orally, by NG tube or parenterally *For patients who are able to eat & drink, sodium is easily accomplished through normal diet *For those unable to eat,Ringer’s lactate solution or isotonic saline [0.9%Nacl]is given *For very low sodium 0.3%Nacl may be indicated *water restriction in case of hypervolaemia

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Sodium imbalan -ce

Definition

causes

Clinical manifestation

Lab findings

management

Hypernat -remia

It is defined as plasma sodium level greater than 145mE q/L

*Ingestion of large amount of concentrated salts *Iatrogenic administration of hypertonic saline IV *Excess alderosterone secretion

• Low grade fever • Postural hypertension •Dry tongue & mucous membrane •Agitation • Convulsions •Restlessness •Excitability •Oliguria or anuria •Thirst •Dry &flushed skin

*high serum sodium 135mEq/L *high serum osmolality >295mOsm/kg

*Administration of hypotonic sodium solution [0.3 or 0.45%] *Rapid lowering of sodium can cause cerebral edema *Slow administration of IV fluids with the goal of reducing sodium not more than 2 mEq/L for the first 48 hrs decreases this risk *Diuretics are given in case of sodium excess *In case of Diabetes insipidus desmopressin acetate nasal spray is used *Dietary restriction of sodium in high risk clients

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Potassium imbalances

Definition

Causes

Clinical manifestation

Lab findings

Management

Hypokalemia

It is defined as plasma potassium level of less than 3.0 mEq/L

*Use of potassium wasting diuretic *diarrhea, vomiting or other GI losses *Alkalosis *Cushing’s syndrome *Polyuria *Extreme sweating *excessive use of potassium free Ivs

*weak irregular pulse *shallow respiration *hypotesion *weakness, decreased bowel sounds, heart blocks , paresthesia, fatigue, decreased muscle tone intestinal obstruction

* K – less than 3mEq/L results in ST depression , flat T wave, taller U wave * K – less than 2mEq/L cause widened QRS, depressed ST, inverted T wave

Mild hypokalemia[3.3to 3.5] can be managed by oral potassium replacement

Moderate hypokalemia *K-3.0to 3.4mEq/L need 100to 200mEq/L of IV potassium for the level to rise to 1mEq/

Severe hypokalemia K- less than 3.0mEq/L need 200to 400 mEq/L for the level to rise to l mEq/L *Dietary replacement of potassium helps in correcting the problem[1875 to 5625 mg/day]

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Definition

Causes

Clinical manifestation

Lab findings

Management

Hyperkalemia

It is defined as the elevation of potassium level above 5.0mEq/L

Renal failure , Hypertonic dehydration, Burns& trauma Large amount of IV administration of potassium, Adrenal insufficiency Use of potassium retaining diuretics & rapid infusion of stored blood

Irregular slow pulse, hypotension, anxiety, irritability, paresthesia, weakness

*High serum potassium 5.3mEq/L results in peaked T wave HR 60 to 110 *serum potassium of 7mEq/L results in low broad P- wave *serum potassium levels of 8mEq/L results in no arterial activity[no p-wave]

*Dietary restriction of potassium for potassium less than 5.5 mEq/L *Mild hyperkalemia can be corrected by improving output by forcing fluids, giving IV saline or potassium wasting diuretics *Severe hyperkalemia is managed by 1.infusion of calcium gluconate to decrease the antagonistic effect of potassium excess on myocardium 2.infusion of insulin and glucose or sodium bicarbonate to promote potassium uptake 3.sodium polystyrene sulfonate [Kayexalate] given orally.

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Calcium imbalances

Definition

Causes

Clinical manifestation

Lab findings

Management

hypocalcemia

It is a plasma calcium level below 8.5 mg/dl

•Rapid administration of blood containing citrate,

•hypoalbuminemia,

•Hypothyroidism •Vitamin deficiency,

•neoplastic diseases,

•pancreatitis

•Numbness and tingling sensation of fingers,

•hyperactive reflexes, • Positve Trousseau’s sign, positive chvostek’s sign ,

•muscle cramps,

•pathological fractures,

•prolonged bleeding time

Serum calcium less than 4.3 mEq/L and ECG changes

1.Asymtomatic hypocalcemia is treated with oral calcium chloride, calcium gluconate or calcium lactate 2.Tetany from acute hypocalcemia needs IV calcium chloride or calcium gluconate to avoid hypotension bradycardia and other dysrythmias 3.Chronic or mild hypocalcemia can be treated by consumption of food high in calcium

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Calcium imbalance

Definition

Causes

Clinical manifestation

Lab findings

Management

Hypercalcemia

It is calcium plasma level over 5.5 mEq/l or 11mg/dl

•Metastatic bone tumors, •paget’s disease,

•osteoporosis

•prolonged immobalisation

•Decreased muscle tone,

•anorexia, •nausea, vomiting,

•weakness , lethargy, •low back pain from kidney stones,

•decreased level of consciousness & cardiac arrest

•High serum calcium level 5.5mEq/L,

• x- ray showing generalized osteoporosis,

•widened bone cavitation,

•urinary stones,

•elevated BUN 25mg/100ml

•elevated creatinine1.5mg/100ml

1.IV normal saline, given rapidly with Lasix promotes urinary excretion of calcium 2.Plicamycin an antitumor antibiotics decrease the plasma calcium level 3.Calcitonin decreases serum calcium level 4.Corticosteroid drugs compete with vitamin D and decreases intestinal absorption of calcium 5. If cause is excessive use of calcium or vitamin D supplements reduce or avoid the same

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REFERENCES ◦ Fluid Therapy by, Rashmi Datta 2008. ◦ Harrisons Book of Internal Medicine, 18Edition. ◦ McGraw-Hill - CURRENT Medical Diagnosis &

Treatment 2010. 49th Edition.

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