ORTHOSTASIS

Course overview

WHEN ONE STANDS UP FROM LAYING DOWN, GRAVITY CAUSES 500 TO 800 MILLILITERS OF BLOOD VOLUME TO SHIFT FROM THE UPPER BODY TO THE LOWER BODY AND SPLANCHNIC CIRCULATION. THIS REDISTRIBUTION OF BLOOD DECREASES VENOUS RETURN AND RIGHT ATRIAL PRESSURE, REDUCING THE STROKE VOLUME AND EVENTUALLY CAUSING A DECREASE IN ARTERIAL BLOOD PRESSURE. ORTHOSTASIS IS A NORMAL PHYSIOLOGICAL RESPONSE OF THE SYMPATHETIC BRANCH OF THE AUTONOMIC NERVOUS SYSTEM TO COUNTERACT THE FALL IN BLOOD PRESSURE WHEN A PERSON TRANSITIONS FROM LAYING DOWN TO AN UPRIGHT POSITION. ORTHOSTATIC HYPOTENSION (OH) IS A CLINICAL FINDING DEFINED BY A FALL IN SYSTOLIC BLOOD PRESSURE GREATER THAN 20 MILLIMETERS OF MERCURY (MMHG) OR A FALL OF IN DIASTOLIC PRESSURE GREATER THAN 10 MMHG WITHIN 3 MINUTES OF STANDING. THIS ACTIVITY ADDRESSES THE PATHOPHYSIOLOGY, EVALUATION, AND MANAGEMENT OF ORTHOSTATIC HYPOTENSION AND EXAMINES THE ROLE OF AN INTERPROFESSIONAL TEAM APPROACH TO THE CARE OF AFFECTED PATIENTS.