Dialysis Youtube Lecture Handouts

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Dialysis/Artificial Kidney

Is a procedure in which principles of diffusion are applied for the treatment of renal failure?

Types

  • Hemo dialysis

  • Peritonial dialysis

Hemo Dialysis

Solution is prepared in which

  • Waste products are absent

  • Electrolytes are adjusted

  • Nutrients are provided

Solution is separated from patient’s blood by a dialyzing membrane.

Blood is normalised by the process of diffusion.

Image of Hemo Dialysis

Image of Hemo Dialysis

Image of Hemo Dialysis

Image of Dialyzer For Hemo Dialysis

Image of Dialyzer for Hemo Dialysis

Image of Dialyzer For Hemo Dialysis

Peritoneal Dialysis

  • In it diffusion takes place across the patient’s own peritoneal membrane

  • About 1 L of sol. is introduced in peritoneal cavity

  • Kept for 20 to 60 min & replaced by fresh fluid

Image of Peritoneal Dialysis

Image of Peritoneal Dialysis

Image of Peritoneal Dialysis

Peritoneal Dialysis

  • Indications

  • In acute renal failure, most of the time condition is reversible. Dialysis can support the patient for a few weeks during the period of crisis

  • In patient of chronic renal failure it is life saving

  • Permanent sol. is Renal Transplantation

Renal Transplantation

  • Were among the first transplants to be done and are among the most successful transplants

  • Both cadavar & live donors are used

  • Detailed antigen typing of both is done

  • Immuno suppression is required

  • Occasionally a graft is rejected

pH expression

  • H+ concentration is very low & their expression is very cumbersome

  • It is customary to express them on a logarithm scale

Normal H+ is 40nEq/L (0.00000004 Eq. /L. & the ph. is

Equation

Equation

Equation

pH of body

  • pH is –ve log. of Equation concentration

  • Normal Equation concen. in body fluids

    • Equation

  • Normal variation

    • Equation

  • Equation Concen. is maintained in a very narrow range

pH of some body fluids

  • Plasma pH

    • Arterial ------7.4

    • Venous -----7.35

  • Extra cellular fluid-----7.35 to 7.45

  • Intra cellular fluid----- 6 to 7.4

  • Urine--------------------6 (4.5 to 8)

  • Gastric HCl-------------0.8

pH

  • pH compatible with life 6.8 to 8.0 & person can live for few hours.

  • Daily H+ production or ingestion about 80mEq

  • These excess of ions must be removed

Acid produced in body

  • Acids produced in body

    • Volatile acids

    • Nonvolatile acids

Volatile Acids

  • Equation a major end product of metabolism

  • Removed by lungs as Equation

  • Equation

  • It accounts for about Equation

Equation onvolatile /Fixed Acids

  • Sulphuric acid—end product of sulpher containing aminoacids eg. Cystenine, methionine metabolism

  • Phosphoric acid—end product of phospholipid metabolism

  • Hydrochloric acid—end product of lysine, arginine & histidine mata.

Fixed Acids

  • Organic Acids

    • Lactic acid---severe anemia

    • Acetoacetic acid, hydroxy butyric acid---uncontrolled D.M.

    • Uric acid---metabolism of nucleoproteins

Base production

  • Negligible amount

  • Bicarbonate---metabolism of organic anions eg. Citrates

  • Ammonia---from metabolism of amino acids is converted to urea, so not important

Buffering of Equation ions

  • Any substance that can reversibly bind H+ ions is buffer

  • Reaction can go in both directions

    Equation

Regul. Of pH

  • Body Buffers—3 Systems

    • Chemical Buffers ---come into action with in fraction of seconds. They keep Equation ions tied up

    • Respiratory System---acts with in minutes Renal System---acts over a period of hours to days. Most efficient

Chemical Buffers

  • Forms I line of defence

  • Three types

    • Bicarbonate buffers

    • Phosphate buffers

    • Protein buffers

Bicarbonate buffer

  • Has two components

    • Weak Acid Equation

    • A salt with strong Base Equation

When a strong acid is added. Like Equation

  • Equation

  • A strong acid is converted to a weak acid

  • If a strong base is added, NaOH

  • Equation

  • Weak base is formed

  • Thus change in pH is minimized

Quantative dynamics

  • BICARBONATE BUFFER

  • Equation is ionized Equation

  • It’s dissociation constant is Equation (1)

  • The amount of free Equation is Equation (2)

  • Equation cannot be measured but is proportionate to Equation Equation (3)

  • The solubility coefficient for Equation is 0.03mmol/mm Hg at body temp.

  • Therefore, equation 3 can be written as Equation (4)

  • Equation concentration is expressed as pH units

  • Equation ions

  • Similarly dissociation constant can be expressed as

  • Equation

  • Thus Equation (5)

  • therefore Equation (6)

  • If we change the sign

    • Equation (7)

    • Equation (8)

Bicarbonate buffer system titration curve

Image of Bicarbonate Buffer System Titration Curve

Image of Bicarbonate Buffer System Titration Curve

Image of Bicarbonate Buffer System Titration Curve

Handerson-Hasselbalch Eq

  • Equation

  • Equation

  • Equation

Phosphate Buffer

  • Two components are

  • Equation

  • Equation

  • important buffer in

  • Renal tubules &

  • Intracellular fluid ( high concentration)

Protein Buffer

  • Have

    • Free carboxyl group

    • Free amino gp.

  • Important intracellular buffer

pK of some Buffer Systems

  • Bicarbonate System-----6.1

  • Dibasic System-----------6.8

  • Proteins-------------------

  • Ammonia-----------------9.0

  • Effective buffers are those with pKs close to the pH. of fluid in which they are operating

Principal Buffers in the body fluids

  • 1 Whole blood

    • Hemoglobin

    • Proteins

    • Bicarbonates

  • 2 Intrestitial fluid--Bicarbonate

  • 3 Intracellular fluid

    • Proteins

    • phosphates

Respiratory System

  • II line defense

  • Hyperventilation----Alkalosis

  • Hypoventilation-----Acidosis

  • Effect is mediated by change in CO2 concen.

Renal System

  • III line defense

  • Acts by

    • Reabsorption of bicarbonates

    • Generation of new bicarbonates

    • H+ excretion

Disorders of Acid-Base Balance

  • Simple

    • Metabolic Acidosis

    • Metabolic Alkalosis

    • Respiratory Acidosis

    • Respiratory Alkalosis

Mixed disorders

  • Metabolic Acidosis & Resp. Acidosis

  • “& Res. Alkalosis

  • Metabolic Alkalosis & Res. Alkalosis

  • “& Res. Acidosis

    Image of Mixed Disorders

    Image of Mixed Disorders

    Image of Mixed Disorders

Anion Gap

  • The concentration of anions & cations must be equal in plasma, so there is no real gap

  • We measure only some anions & cations

  • The anion gap is a diagnostics concept

Anion Gap

  • Is the difference between unmeasured anions & unmeasured cations

  • Equation

  • Equation

  • Equation

  • Normal range is Equation