Blood studies are critical in the medical field, enabling healthcare professionals to assess a patient's health status accurately. This page will focus on two significant blood studies: Arterial Blood Gas (ABG) and Venous Blood Gas (VBG).
Arterial Blood Gas (ABG)
Arterial Blood Gas (ABG) studies are crucial for assessing the lungs' ability to supply oxygen and remove carbon dioxide, reflecting the patient's ventilation status. They also help understand the kidneys' capacity to reabsorb or excrete bicarbonate ions, indicating metabolic status by assessing conditions such as metabolic acidosis or alkalosis.
Purpose
ABGs are often ordered for acutely ill patients or those with respiratory disorders. They measure the blood's pH, oxygen-carrying capacity, and oxygen, carbon dioxide levels, and bicarbonate ions. If the oxygen level in the blood decreases, it can lead to health complications, as body tissues will not receive enough oxygen.
Nursing Responsibilities
When conducting an ABG study, it is important to note whether the patient uses oxygen and at what percentage and liters per minute (L/min). Changes in oxygen therapy or interventions should be avoided for 20 minutes before obtaining the sample. Blood collection involves puncturing the radial or femoral artery or using an arterial catheter. To ensure accurate results, expel all air bubbles from the heparinized syringe and immediately place the sample on ice unless it will be analyzed within one minute.
Venous Blood Gas (VBG)
VBG studies estimate the balance between the amount of oxygen used by tissues and organs and the amount of oxygen returning to the right side of the heart in the blood.
Purpose:
VBG studies are performed when drawing ABGs is not feasible. They can be obtained by withdrawing blood from the venous circulation. Mixed venous oxygen saturation (SO2) levels, the most accurate indicator of this balance, can only be obtained from blood samples drawn from a pulmonary artery catheter.
Nursing Responsibilities
Nursing responsibilities for VBG studies include ensuring the correct collection of blood samples. The best location to draw blood is a central venous catheter inserted in the superior vena cava. It is the best alternative for patients without pulmonary artery catheters and closely approximates SO2 levels.
In conclusion, ABG and VBG studies are crucial for assessing a patient's health status, particularly the body's oxygen supply and utilization. Understanding these studies enables healthcare professionals to make informed decisions about treatment strategies.
