So normal values of abg in new york might differ from normal abg values in washington dc. Another is base excess or base deficit this measures the presence of extra bases or alkaline. Abg interpretation is especially important in critically ill patients. Bicarbonate hco 3 helpful in critically ill patients. Arterial blood gas abg analysis lippincott nursingcenter. In this article, i will assume that we have avoided all of those pitfalls and and will discuss how to interpret valid abg results. We will provide arterial blood gas value chart for people living at sea level. Arterial blood gas abg test measures the acidity ph and levels of oxygen and carbon dioxide in the blood.
Arterial blood gases abgs critical lab values medical estudy. Learn abg lab values with free interactive flashcards. Partial compensation ph is still abnormal, and the other value is abnormal in an attempt to help normalise the ph. This is particularly important if your patient is known to have chronic respiratory disease with existing chronic abg changes. Researcher made questionnaire contained four sections i. Arterial blood gases abgs are measured in a laboratory test to determine the extent of compensation by the buffer system.
They are compensating but your patient might still be in trouble. Interpreting an arterial blood gas abg is a crucial skill for physicians, nurses, respiratory. Abg quick interpretation parameter acidosis normal alkalosis reflects ph 7. The basic components of arterial blood gas are divided as follows. For you to better understand the key elements in an abg test, it is important for you to know the definition of all the normal values. This study guide is the ultimate resource for arterial blood gases, values, practice questions, and more. Acid base balance university hospitals bristol nhs. Some abg results also show hemoglobin and serum electrolyte values. Before getting stuck into the details of the analysis, its important to look at the patients current clinical status, as this provides essential context to the abg result.
Normal values to check in abg before actually starting to interpret the abg reports, one needs to remember the following normal values, without which, it is impossible to analyze anything. So heres are first example and ive put the normal values up here for us as a reference. Arterial blood gas interpretation felicia ratnaraj internal medicine pgy 3 pm report. When interpreting arterial blood gas abg results, it is essential to know what abg values are considered normal. The usefulness of this diagnostic tool is dependent on being able to correctly interpret the results. Patients with normal kidney function are able to excrete excess bicarbonate in the urine so if metabolic alkalosis is maintained there is an inability to excrete bicarbonate in the urine. I definitely recommend that you go through the normal values several times until the it sticks.
Body will not overcompensate when it comes to acidbase balance so. It also measures your bodys acidbase ph level, which is usually in balance when youre healthy. There are a few other things we can receive in an abg one is lactic acid normal value is 0. Arterial blood gas abg analysis is an essential part of diagnosing and managing a patients oxygenation status and acidbase balance. Question 1 of 3 a nurse is caring for a client who requires a mechanical ventilator for breathing assistance. The normal values of abg differ in people living at different height from sea level.
It explains each component in turn followed by clinical examples to work through. Arterial blood gas test normal values shows values for ph, oxygen, carbon dioxide, bicarbonates, lactic acid levels and oxygen saturation. Blood gases is a measurement of how much oxygen and carbon dioxide is in your blood. Interpreting an arterial blood gas abg is a crucial skill for physicians, nurses, respiratory therapists, and other health care personnel. If the ph is not in the normal range and the abg is not trying to correct itself then the compensation result is. Arterial blood gas abg interpretation for medical students, osces and mrcp paces this section presents how to interpret arterial blood gases. This is an indicator of the total buffer base of the body. Blood gases medical tests ucsf benioff childrens hospital. Sometimes abgs can be very intimidating because there are a lot of values to look at, but hopefully this will help to. If all 3 values are normal then your patient is fine leave them alone. Abg results may indicate decreased o2 levels hypoxia, decreased or increased co2 levels hypo or hypercapnia, acidosis decreased ph, alkalosis increased ph. Fio2 the percentage of inspired oxygen that you took the blood gas on ph normal range 7. At altitudes of 3,000 feet and above, the oxygen values are lower.
Interpretation of arterial blood gases abgs david a. You can check all the values seen in abg on wikipedia. If the ph is not within the normal range but the abg is trying to correct itself then the compensation result is partially compensated. Interpretation of the arterial blood gas free open access. Note that these may vary slightly between analysers. For example abgs with an alkalemic ph may exhibit respiratory acidosis and metabolic alkalosis. The next value is the carbon dioxide level, and this will tell you if the problem is respiratory in origin, as co 2 is. Your respiratory system andor buffers are working properly. An arterial blood gas abg test measures oxygen and carbon dioxide levels in your blood. Subsequently, all values will be assumed to be arterial.
Apr 20, 2020 firstly, it is important to know what values you are looking at and what is considered normal. Abg interpretation free download as powerpoint presentation. Arterial blood gases free open access medical education. Oct 18, 2019 arterial blood gas abg normal lab values. As noted above, if the ph is low, the patient has an acidemia. Now that youve learned the abg normal values, we can get move on to learn exactly how to interpret abg results. In cases where blood gas values do not fall into any of the above classifications, an answer unable to determine will appear when using the interpreter. With that in mind, the main steps in interpreting an arterial blood gas in greater detail are presented below.
Laboratory values see inside back cover for continuation. Normal value ranges may vary slightly among different laboratories. Normal arterial carbon dioxide pressure pco 2 is 3545 mmhg. Interpretation of arterial blood gas pubmed central pmc. Abgs provide information about acidbase balance and the levels of o2 and co2 in the blood. Normal values references ranges free medical student revision notes medical assistant graduation cap med school ideas for 2019 normal values references ranges. Such information is vital when caring for patients with critical illnesses or respiratory disease.
Choose from 487 different sets of abg values flashcards on quizlet. A normal pao2 in a patient on high flow oxygen this is abnormal as you. Arterial blood gas analysis for emergency medicine registrars. Arterial blood gas normal values and interpretation by dr. As we start our arterial blood gas course, i want to start by helping you understand what is included in an abg and why we use abgs in our patients. Hco 3 to decide whether compensatory mechanisms are at work once the acidbase disorder is identified as respiratory or metabolic, we must look for the degree of compensation that may or may not be occurring. Reference guide for board exams by johnny lung respiratory fundamentals learning all the different normal values is an important step for respiratory therapy students when it comes to making informed clinical decisions. The nurse checks the clients routine abg values and notes. Abg interpretation free download before you go, dont forget to download study guide for free no strings.
You now have access to all the normal values that you must know, not only for respiratory therapy school, but for the board exams as well. The following sixstep process helps ensure a complete interpretation of every abg. Understanding arterial blood gases abgs nysna continuing. Normal is 3545mmhg hypercapnoea is 45 mmhg and is reflective of hypoventilation hypocapnoea is normal values of abg differ in people living at different height from sea level. An abg test measures the blood gas tension values of the arterial partial pressure of oxygen pao2, and the arterial partial pressure of carbon dioxide pac02, and the bloods ph. Before actually starting to interpret the abg reports, one needs to remember the following normal values, without which, it is impossible to analyze anything. Arterial blood gases abgs critical lab values medical. Normal arterial oxygen pressure po 2 is 80100 mmhg. Interpreting abgs arterial blood gases made easy ausmed. The next value is the carbon dioxide level, and this will tell you. It measures the acidity ph and the levels of oxygen and carbon dioxide in arterial blood. Jul 05, 2019 normal pao 2 decreases 1 mmhg for every year over age 60. This is a measure of the % of oxygen that is attached to hemoglobin in red blood cells. Normal values for arterial blood gas abg normal values are given below.
Arterial blood gas values chart abg values and meanings. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The abcs of abgs know the normal values for ph, p co2, and hco 3. Arterial blood gas is usually advised to patients suffering from respiratory illnesses or under critical care. However, during the first three months of life ph was 0,02 units lower than during the 4th to 12th month. Arterial blood gas primer clinical respiratory diseases.
So step 1 is determine whether each thing is acidosis, alkalosis, or normal. Woodruff, msn, rnbc, cns, cmsrn, cen 6 easy steps to. This is bicarbonate, a chemical buffer made in the kidneys to neutralize acids. Its a test that is used to assess how well oxygen is being distributed throughout the body and how well carbon dioxide is being removed. From this baseline, you can then begin to recognise significant variations in a patients results, which could indicate clinical deterioration. Oxygen saturation sao2 94 100% bicarbonate hco3 22 28 meql.
But it is often encountered that many students dont know how to read abg, and thats why we are providing arterial blood gas. Choose from 483 different sets of abg lab values flashcards on quizlet. Abg interpretation a guide to understanding abgs geeky medics. Arterial blood gases abgs lab and diagnostic procedure. Arterial blood gas interpretation, abg analysis, rules for rapid abg analysis, anion gap, approach to mixed disorders introduction arterial blood gas abg analysis is an essential part of diagnosing and managing a patients oxygenation status and acidbase balance. Partial compensation ph not quite back to normal yet.
If the ph is above this range, the patient has an alkalemia. Arterial blood gas abg interpretation for medical students. If your abg differ from it, then refer to normal value shown by the lab in your locality. Abg interpretation what numbers do you get on an abg. The normal values for acidbase parameters are as follows. The first value is the ph, which measures how many hydrogen ions are in the sample. Abg values one would see with metabolic alkalosis would be. You cant fully compensate metabolic alkalosis you can only hypoventilate a bit nb. The mean of the arterial ph values in the entire group corresponds to the normal adult values. In a previous article, the pitfalls of arterial blood gases, i described how simple preanalytical, analytical, and postanalytical errors can produce arterial blood gas test results abgs that are of little or no value, and perhaps even dangerous.
The most important points when assessing a patient are the history, examination and basic observations. The arterial blood gas provides the following values. Its possible to have more than one disorder influencing blood gas values. In addition, the arterial oxygen saturation sa02 can be determined. These disorders are termed complex acidbase or mixed disorders. This determines if the blood is acidotic or alkalotic.
The blood may be collected from the radial artery in the wrist, the femoral artery in the groin, or the brachial artery in the arm. Below are a few examples to demonstrate how important context is when interpreting an abg. An arterial blood gas, or abg for short, is a test that measures the blood levels of oxygen pao2, carbon dioxide paco2, and acidbase balance ph in the body. Related entries swiss cheese model paediatric vital signs potassium sodium the anion gap labs help me pass nursing school. Low values high values blood gas arterial blood gas, adult ph 7. Normal is 95% in healthy humans avg is 98% for a healthy pt. The first value a nurse should look at is the ph to determine if the patient is in the normal range, above, or below. Thats a basic look at how gas is measured, now lets look at how we get these gases into our lungs. Like most medical normal values and ranges, the definition can vary slightly, but generally the following definitions apply. Be sure to know the normal ranges and units for the analyser you will be using.
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