Low values high values blood gas arterial blood gas, adult ph 7. The arterial blood gas provides the following values. 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. The real value of an abg comes from its ability to provide a nearimmediate reflection of the physiology of your patient, allowing you to recognise and treat pathology more rapidly. Arterial blood gas analysis is used to measure the ph and the partial pressures of oxygen and carbon dioxide in arterial blood. Arterial blood gas analysis for emergency medicine registrars. For example abg s with an alkalemic ph may exhibit respiratory acidosis and metabolic alkalosis. The normal values for acidbase parameters are as follows. If the ph is not within the normal range but the abg is trying to correct itself then the compensation result is partially compensated. We will provide arterial blood gas value chart for people living at sea level. However, during the first three months of life ph was 0,02 units lower than during the 4th to 12th month. The investigation is relatively easy to perform and yields information that can guide the management of acute and chronic illnesses. The abg instructional guide begins with the basics and stepbystep advances to more complex double and triple disorders. Everyone can read an electrolyte level, but when faced with a list of abgs, most nurses wilt.
Note that these may vary slightly between analysers. If the ph is not in the normal range and the abg is not trying to correct itself then the compensation result is. The mean of the arterial ph values in the entire group corresponds to the normal adult values. Laboratory values see inside back cover for continuation. Arterial blood gas values can be directly measured from indwelling arterial catheters or estimated from intermittent peripheral artery punctures, arterialized capillary bed samples, and central venous blood samples. Fortunately, there are some easy ways to remember how to decipher these important lab results. Use of the alveolararterial oxygen gradient in the diagnosis of pulmonary embolism michael j.
For example abgs with an alkalemic ph may exhibit respiratory acidosis and metabolic alkalosis. The normal values listed herecalled a reference rangeare just a guide. An abg test measures the blood gas tension values of the arterial partial pressure of oxygen pa02, and the arterial partial pressure of carbon dioxide pac02, and the bloods ph. Arterial blood gas abg interpretation for medical students. Arterial blood gases you are a new staff member working in the emergency department ed during your induction you are introduced to the practical workings of the point of care arterial blood gas abg machine in the ed. An acid is a hydrogen ion donor a base is a hydrogen ion acceptor the acids produced by metabolism have to be either buffered or excreted to maintain blood ph within normal parameters. Its possible to have more than one disorder influencing blood gas values. Normal anion gap metabolic acidosis is also called hyperchloremic acidosis, because instead of reabsorbing hco3 with na, the kidney reabsorbs cl.
An abg is a blood test that measures the acidity, or ph, and the levels of oxygen o2 and carbon dioxide co2 from an artery. It measures the acidity ph and the levels of oxygen and carbon dioxide in arterial blood. It also has some applications in general practice, such as assessing the need for domiciliary oxygen therapy in patients with chronic obstructive pulmonary disease. If po2 is within the normal range, evaluate the next. But it is often encountered that many students dont know how to read abg, and thats why we are providing arterial blood gas. This is an indicator of the total buffer base of the body.
There is a correlation between the arterial and venous pco 2, but the confidence intervals are large with an average difference ranging from 5. Body will not overcompensate when it comes to acidbase balance so. A primer on arterial blood gas analysis uw courses web. Abg results may indicate decreased o2 levels hypoxia, decreased or increased co2 levels hypo or hypercapnia, acidosis decreased ph. Interpretation of arterial blood gases abgs david a. Partial compensation ph is still abnormal, and the other value is abnormal in an attempt to help normalise the ph.
This information indicates a patients acidbase balance, the effectiveness of their gas exchange and the state of their ventilatory. Abg values expected in various acidbase conditions. The normal values of abg differ in people living at different height from sea level. Identify normal arterial blood gas values and interpret the meaning of abnormal values. Interpreting an arterial blood gas abg is a crucial skill for physicians, nurses, respiratory therapists, and other health care personnel. Compensatedph will be back to normal but on the acid or basic side. Abstract arterial blood gas analysis is a common investigation in emergency departments and.
Normal arterial carbon dioxide pressure pco 2 is 3545 mmhg. An arterial blood gas abg test will not be done on an arm used for dialysis or if there is an infection or inflammation in the area of the puncture site. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Normal is 95% in healthy humans avg is 98% for a healthy pt. This is particularly important if your patient is known to have chronic respiratory disease with existing chronic abg changes. Abg values expected in various acid base conditions. Arterial blood gas measurements are the gold standard by which the adequacy of oxygenation and ventilation is assessed. There will also be a slower response from a change in the acidalkali content of the urine by the kidneys.
Pdf arterial blood gases abg results reflect underlying pathology and. This table is able to classify most clinical blood gas values but not all. Normal metabolism results in the production of acids. Arterial blood gas analysis is a common investigation in emergency departments and intensive care units for monitoring patients with acute respiratory failure. Its a test that is used to assess how well oxygen is being distributed throughout the. Over 50 sample problems are discussed in detail in the guide. Acid base balance why is acid base balance important. The following sixstep process helps ensure a complete interpretation of every abg. However, the understanding of abgs and their interpretation can sometimes be. Critical values abg s any abg value marked as outside of normal range will be considered a critical value unless otherwise defined, designated or ordered by the physician. Oct 18, 2019 arterial blood gas abg normal lab values. Crapo et al 1 defined reference equations in 1999 for healthy nonsmokers for arterial blood gas and co oximeter analytes at two different altitudes sea level and 1400m.
The most common abg abnormalities detected relate to an excess of acid. An arterialblood gas abg test measures the amounts of arterial gases, such as oxygen and carbon dioxide. An abg test requires that a small volume of blood be drawn from the radial artery with a syringe and a thin needle, but sometimes the femoral artery in the groin or another site is used. So normal values of abg in new york might differ from normal abg values in washington dc. Arterial and venous blood gas analysis international. Use of the alveolararterial oxygen gradient in the. Data were rearranged as low, normal, and high according to the reference range and comparison of results was done on both the analyzers. Abg interpretation is especially important in critically ill patients. Arterial blood gas values chart abg values and meanings. Ph, co2, hco3 and how to understand and interpret arterial blood gas values in this abg course.
Even for the respiratory system, ph rather than oxygen is the priority. 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. Aug 22, 2017 what are the most common arterial blood gas abnormalities. However, it is not possible to understand its type with ph. In abg, ph shows a status of acidosis or alkalosis. Thats a basic look at how gas is measured, now lets look at how we get these gases into our lungs. Common laboratory values cheat sheet diagnostic tests are crucial in any aspect of clinical practice since they assist clinicians in establishing and determining the particular condition of the patient. A primer on arterial blood gas analysis by andrew m. Blood gases is a measurement of how much oxygen and carbon dioxide is in your blood. However, during the first three months of life ph was 0,02 units lower than during the. Be sure to know the normal ranges and units for the analyser you will be using. Are sodium and potassium results on arterial blood gas. This will be the only video you will need to interpret your abgs. Arterial blood gas an overview sciencedirect topics.
Arterial blood gas interpretation, abg analysis, rules for rapid abg. Malinoski 2005, kelly 2001, mccanny 2012, malatesha 2007, rang 2006, mckeever. Arterial blood gas analysis workshop learning outcomes at the end of this workshop candidates should be able to. You are watching an educational video about interpreting abgs. Beyond that, however, blood gas interpretation can seem like a. Measurement of arterial blood gases abgs involves a sample of blood being taken from an artery most commonly from the pulsation at the wrist. Arterial blood gases abgs critical lab values medical.
Both systems are primarily concerned with keeping blood ph in the normal range. Blood gases medical tests ucsf benioff childrens hospital. To see how to perform an arterial blood gas check out our guide here. The normal ranges of co2, hco3, and ph from our hospital clinical laboratory were used to construct the diagnostic rules. Abg interpretation a guide to understanding abgs geeky. An abg is a blood test that measures the acidity, or ph, and the levels of oxygen o2 and carbon dioxide co2 from an artery the test is used to check the function of the patients lungs and how well they are able to move oxygen into the blood and remove carbon dioxide. Abg quick interpretation parameter acidosis normal alkalosis reflects ph 7. Abg values based on neonatal age prebirth 5 min 17 days scalp after birth after birth. The difference in the pco2 measurements between the vbg and abg is the most contested in the literature.
These ranges vary from lab to lab and depend upon the elevation above sea level. The interpretation of arterial blood gases australian. 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. So2 may be as low as 90% in healthy patients of advanced age. Abg predicted normal values arterial blood gas analysis is important in managing patients with cardiopulmonary diseases. If you want to put your abg interpretation skills to the test, check out our abg quiz. Arterial blood gas analysis for emergency medicine registrars very helpful investigation in critical care you should be an expert you need a system, and must be thorough they are not really that hard part 1 the basics part 2 compensation part 3 metabolic acidosis part 4 metabolic alkalosis. Now lets look at arterial blood gas results when there is evidence of partial compensation. If one system is disturbed, the other tries to restore balance. An arterial blood gas abg test measures the acidity ph and levels of oxygen and carbon dioxide in the blood.
In addition, the arterial oxygen saturation sa02 can be determined. Interpret the results of various arterial blood gas samples. Pdf blood gas analysis for bedside diagnosis researchgate. The present article aims to simplify arterial blood gas analysis for a rapid and easy bedside interpretation. Such information is vital when caring for patients with critical illnesses or respiratory disease. Abgs provide information about acidbase balance and the levels of o2 and co2 in the blood. Technical errors risk of alteration of results with. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. Normal values for blood gas analysis are given in table 81, and capillary blood gases are discussed in a. Interpreting an arterial blood gas abg is a crucial skill for physicians, nurses. Normal values for arterial blood gas abg normal values are given below. A procedure called the allen test may be done to ensure that blood circulation to your hand is normal. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Arterial blood gases abgs are measured in a laboratory test to determine the extent of compensation by the buffer system.
These disorders are termed complex acidbase or mixed disorders. As you struggle to listen to the machine company representative talking about cleaning the machine. Arterial blood gas abg reference normal predicted values. The most common causes of normal anion gap acidosis are gi or renal bicarbonate loss and impaired renal acid excretion. In abg results, so 2 is derived from po2 using the oxygenhemoglobin dissociation curve. This is a measure of the % of oxygen that is attached to hemoglobin in red blood cells. Arterial blood gasses, or abgs, may be among the most complex and confusing parts of nursing practice. Your lab may have a different range for whats normal. Identify the relationship between oxygen saturation and pao2 as it relates to the oxyhemoglobin dissociation curve. This can either be as a result of the lungs not working properly called respiratory acidosis or from a buildup of acid from metabolic causes, usually as a result of tissues being starved of oxygen called a metabolic acidosis. Definitions acidosis acidemia occurs when ph drops below 7. All these problems in the abg challenge are included in oakes abg instructional guide free within this website to show how the answers were derived.
This information indicates a patients acidbase balance, the effectiveness of their gas exchange and the state. Arterial blood gas abg values and the alveolararterial oxygen aa gradient are sensitive indicators of pulmonary pathology. Knowledge about interpretation of abgs is consequently. Understanding arterial blood gases abgs nysna continuing. Fio2 the percentage of inspired oxygen that you took the blood gas on. Normal anion gap hyperchloremic metabolic acidosis.