Overview
Introduction
Arterial blood gas (ABG) analysis is a bedside diagnostic tool that measures the adequacy of oxygenation, ventilation, and acid base balance from a sample of arterial blood.
Arterial blood gas (ABG) analysis is a bedside diagnostic tool that measures the adequacy of oxygenation, ventilation, and acid-base balance from a sample of arterial blood. For the NCLEX-RN, ABG interpretation is consistently high-yield because it threads through questions on respiratory distress, COPD, asthma, mechanical ventilation, diabetic ketoacidosis, sepsis, vomiting, and prolonged nasogastric suction. The expectation is that you can read an ABG quickly, name the primary disorder, judge whether compensation is occurring, and connect the result to a safe nursing action. Memorize the normal ABG values exactly: - pH: 7.35 to 7.45 (acidosis below 7.35; alkalosis above 7.45). - PaCO2: 35 to 45 mmHg — the respiratory component, the 'acid tank' controlled by the lungs. - HCO3 (bicarbonate): 22 to 26 mEq/L — the metabolic component, the 'base buffer' controlled by the kidneys. - PaO2: 80 to 100 mmHg — oxygenation. - SaO2: 95 to 100 percent. - Base excess: negative 2 to positive 2. A reliable memory tool is ROME: Respiratory Opposite — pH and PaCO2 move in opposite directions (a rising CO2 lowers the pH, a falling...
