Angel Das Y.L 2nd year MBBS student FLUID IMBALANCE Angel Das Y.L 2nd year MBBS student

TOTAL BODY WATER

COMPOSITION OF FLUID COMPARTMENTS ECF compartment – Na+,Cl-,HCO3- ICF compartment – K+,Mg2+,Phospates & proteins Conc: gradient – Na+-K+ pump

Movement of BODY FLUIDS Diffusion Osmosis Active Transport Filtration

DIFFUSION Fluid Solutes High Solute Concentration Low Solute Concentration

Low Solute Concentration, High Fluid Concentration OSMOSIS Fluid Low Solute Concentration, High Fluid Concentration High solute Concentration, Low Fluid Concentration

ACTIVE TRANSPORT ATP ATP ATP ATP Na + Na + Na + Na + Na + Na + Na + K + K + K + K + K + K + ATP K + K + K + K + K + K + K + K + K + ATP K + K +

FLUID BALANCE Normally INTAKE = OUTPUT

Disorders in fluid balance BODY FLUID CHANGES Disorders in fluid balance Volume Composition Concentration

Volume Changes Extracellular volume deficit most common fluid disorder. either Acute Chronic

Acute Chronic CVS & CNS signs Tissue signs such as decrease in skin turgor & sunken eyes

Weight loss

Cardiac Collapsed neck Veins Tachycardia Hypotension

Renal .Azotemia Oliguria GI .Ileus

Common Cause – Volume deficit in Surgical Patients Loss of GI fluids- Nasogastric suction,Vomitting,Diarrhea Sequestration secondary to soft ts injuries, burns & intra abdominal processes such as peritonitis, obstruction or prolonged surgery

Extra cellular Volume Excess Iatrogenic Renal dysfunction Secondary to CHF Cirrhosis

Generalized Weight Gain Edema

Cardiac Increased cardiac output Increased central venous pressure Distended neck Veins Murmur

GI Bowel Edema Pulmonary Pulmonary edema

Volume Control By osmoreceptors & baroreceptors ↑ ADH Secretion DECREASED FLUID VOLUME Stimulation of thirst center in hypothalamus ↑ ADH Secretion Renin-Angiotensin- Aldosterone System Activation ↑ Water resorption Person complains of thirst ↑ Sodium and Water Resorption

Concentration Changes Hyponatremia & Hypernatremia Composition Changes K+ abnormalities Ca2+ abnormalities Mg2+ abnormalities

FLUID THERAPY Type of fluid- vol. status, conc, or compositional abnormality Lactated ringer soln & normal saline – isotonic useful in replacing GI loss & correcting extra cellular volume deficit

Alternative Resuscitative Fluids Hypertonic saline solutions -in closed head injuries -increase cerebral perfusion & intracranial pressure -decrease brain edema

2.Colloids – Volume expanders -but under severe hemorrhagic shock – worsens edema -4 types – Albumin, dextrans, hetastarch & gelatins

Pre operative Fluid Therapy Volume deficit – fluid replacement – isotonic crystalloid-depending on serum electrolyte values Close monitoring

Intra operative Fluid Therapy Hemodynamic instability during anesthesia avoided by correcting known fluid loss & providing adequate maintenance fluid therapy-pre operatively Saline administration

Post Operative Fluid Therapy Based on patient’s vol status & ongoing fluid loss Initially- isotonic Later –dextrose & normal saline