STARLINGS EQUATION KEEP ON MOVIN DONT STOP Group

STARLING’S EQUATION KEEP ON MOVIN’ DON’T STOP Group Members: Sahra Adan, Claire Anderson, Aminah Coleman, Wai Chum, Joseph Early, Mindy Gunn, Kyle Mc. Intyre, Monicah Ngugi, Kathryn Sjolund, Lise Thorsvig, Lindsey Tripp, & Vincent Witwer

FILTRATION THROUGH MEMBRANES AFFECTED BY 3 FACTORS: • HYDROSTATIC PRESSURE (HP) GRADIENT (PUSHING) • ONCOTIC PRESSURE GRADIENT (OP) (PULLING) • PERMEABILITY OF MEMBRANE (THROUGH WHAT? ) WHERE DOES WATER GO? …. IN THE DIRECTION WHERE THE FORCE IS GREATER!!!!! NET: HP (SIDE A) – HP (SIDE B) NET: OP (SIDE A) – OP (SIDE B) B A

MEMBRANE CHARACTERISTICS: LP, S (LITTLE) AND S (BIG) LP AND S (BIG) AFFECT HYDROSTATIC PRESSURE: LP- POROSITY OF THE MEMBRANE S (BIG) - MEMBRANE SURFACE AREA S (LITTLE) AFFECTS OSMOTIC PRESSURE: • S (LITTLE)- PERMEABILITY OF A MEMBRANE TO A SOLUTE • RANGES FROM 0 (COMPLETELY PERMEABLE) TO 1 (COMPLETELY IMPERMEABLE) • SOLUTE DIFFUSION AS PERMEABILITY

THE MATH OF STARLING’S EQUATION MEANS Movement of water between interstitial space and capillaries Increased hydrostatic pressure = positive net filtration inside the capillary Increased oncotic pressure = negative net filtration Interstitial space

IMPORTANCE OF STARLING’S LAW This affects the flow of fluid and filtrates into and out of your capillaries. . . At the ARTERIAL end of the capillary: Net filtration pressure is POSITIVE, causing water, oxygen and nutrients to be pushed OUT of the capillary and into the interstitial fluid. At the VENOUS end of the capillary: Net filtration pressure is NEGATIVE, allowing the veins to pick up excess water, carbon dioxide, and other wastes from the interstitial fluid.

CLINICAL CORRELATIONS: PLEURAL FLUID ANALYSIS HIGH [ PROTEIN ] LOW [PROTEIN ] DUE TO DAMAGED CAPILLARIES DUE TO HYDROSTATIC PRESSURE -OR- ONCOTIC PRESSURE “EXUDATE” “TRANSUDATE” INFLAMMATION, INFECTION, TRAUMA, CHF, CIRRHOSIS, SEVERE MALNUTRITION,

CLINICAL CORRELATIONS FLUID COLLECTIONS ALWAYS RESULT FROM A CHANGE IN ONE COMPONENT OF STARLING’S LAW ASCITES, PERIPHERAL EDEMA, PULMONARY EDEMA, PLEURAL EFFUSION

CLINICAL CORRELATIONS: ALBUMIN GRADIENT = PLASMA ALBUMIN – ASCITIC ALBUMIN HIGH GRADIENT >1. 1 G/DL LOW GRADIENT < 1. 1 G/DL • CIRRHOSIS MALIGNANCY • HEPATITIS TB Ascites • CHF PANCREATIC DISEASE • PORTAL VEIN THROMBOSIS NEPHROTIC SYNDROME • MYXEDEMA

SUMMARY

IN WORDS • STARLING’S LAW EXPLAINS THE MAINTENANCE OF FLUID BALANCE BETWEEN THE VASCULATURE AND THE INTERSTITIAL SPACE. • FLUID BALANCE IS DETERMINED BY HYDROSTATIC AND ONCOTIC PRESSURE BALANCE • IN A HEALTHY PERSON: HIGH HYDROSTATIC PRESSURE FORCES WATER TO FILTER OUT OF CAPILLARIES AT THE ARTERIAL END • AT THE VENOUS END, HYDROSTATIC PRESSURE IS DECREASED, THUS ONCOTIC PRESSURE - MAINLY THE PULL OF THE PLASMA PROTEINS – RETURNS WATER INTO THE VASCULATURE • IN A DISEASE STATE: HYDROSTATIC OR ONCOTIC PRESSURE ALTERED AND WATER FLOWS FROM THE VASCULATURE TO THE INTERSTITIAL SPACE • MEMBRANE PERMEABILITY ALSO IMPACTS THE FLOW OF WATER.