Weve created this guide, which aims to provide a structured approach to abg interpretation whilst also increasing your understanding of each results relevance. Arterial blood gases play an important role in the workup and management of critically ill patients and patients with a variety of pulmonary complaints and disorders. Arterial blood gas sampling society for acute medicine. It also measures your bodys acidbase ph level, which is usually in balance when youre healthy. From this baseline, you can then begin to recognise significant variations in a patients results, which could indicate clinical deterioration. This information indicates a patients acidbase balance, the effectiveness of their. Jan 26, 2015 other useful information from arterial blood gases. Pdf blood gas analysis for bedside diagnosis researchgate. Arterial blood gas analysis an overview sciencedirect topics. Unlike other blood tests, which are either high or low, abgs present the doctor with six numbers that need to be interpreted as one result. Table 1 report of arterial blood gases for the hypothetical patient described view this table.
Arterial blood gas abg analysis lippincott nursingcenter. Arterial blood gas analysis abg, is a test that measures the amount of oxygen o2 and carbon dioxide co2 in the blood, as well as the acidity ph of the blood. This primer describes a clinical approach to interpreting arterial blood gases. Print primer 237k pdf uwnet id required clinical cases in arterial blood gas analysis. Arterial blood gas analysis is a common investigation in emergency departments and intensive care units for monitoring patients with acute respiratory failure. Carbon dioxide co2 elimination through respiration. Patients are often required to be checked for arterial blood gas analysis to find what exactly is happening in the body of patients system. An arterial blood gas abg analysis can tell you about a patients oxygenation, acidbase balance, pulmonary function, and metabolic status. Analysis of arterial blood gases a comprehensive approach japi.
Blood gas values mixed venous gases measures oxygen left in the. Venous blood is good for hco3 estimation but bad for ph, pco 2 and po 2. Following are the steps one should follow when reading the arterial blood gas and interpreting the values simultaneously. The results of abg testing will often influence the treatment that patients receive. The investigation is relatively easy to perform and yields information that can guide the management of acute and chronic illnesses. While arterial samples are the best for diagnostic reasons, they do provide some challenges for nurses and providers. It is an essential part of diagnosing and managing a patients oxygenation status and acidbase balance. As pao2 increases, more oxygen diffuses into the red blood cells, where it combines with hemoglobin to form oxyhemoglobin. Introduction interpreting the analysis of an arterial blood sample to determine a patients acidbase status and respiratory gas exchange is a key component in the management of any ill patient.
While drawing venous sample make sure that no tourniquet is applied, artery is not compressed and sample is drawn against the flow of blood towards heart. Arterial blood gas interpretation demystified physician assistant. Arterial blood gas abg analysis is an essential part of diagnosing and managing a patients oxygenation status and acidbase balance. Each case is then followed by an explanation of the acidbase status, the oxygenation status and a summary of the patients clinical picture. When one thinks of abg analysis, oxygenation may come to mind first. Arterial blood gas analysis is used to measure the ph and the partial pressures of oxygen and carbon dioxide in arterial blood. Arterial blood gases indications and interpretation. Blood is drawn anaerobically from a peripheral artery radial, brachial, femoral, or dorsalis pedis via a single percutaneous needle puncture, or from an indwelling arterial cannula or catheter for multiple samples. Overview abg sampling interpretation of abg gas exchange acid base status.
In case of delay, the sample should be placed in ice and such iced sample can be processed upto 2 hours without affecting the blood gas values. A primer on arterial blood gas analysis family medicine residency. An arterial blood gas abg test measures oxygen and carbon dioxide levels in your blood. Arterial blood gases primarily provide information regarding oxygenation i. Apr 03, 2020 once the blood is obtained, it is either sent to the hospitals central lab for analysis or tested by the respiratory therapist on the units blood gas analyzer.
Arterial blood gas abg interpretation is something many medical students find difficult to grasp weve been there. The bodys regulation of ph is influenced by both the respiratory and the. Oxygenation of blood through gas exchange in the lungs. In this guide, we will teach you the eight 8 steps on how to interpret and analyze arterial blood gas abg results using the tictactoe method. The body normally extracts 25% of available oxygen and leaves 75% in reserve in times of stress or illness. The interpretation of arterial blood gases australian. Apr 20, 2020 when interpreting arterial blood gas abg results, it is essential to know what abg values are considered normal.
Abg is the only investigation, which can document, specify and quantitate the respiratory failure. This indispensable tool helps you assess and monitor critically ill patients in the icu or other critical care settings. An arterial blood gas test can find ways to help your lungs do their job. An arterial blood gas abg test measures the amounts of arterial gases, such as oxygen and carbon dioxide. Arterial blood gas abg analysis the arterial blood gas abg measures the acidbase balance ph and oxygenation of an arterial blood sample. Interpreting abgs arterial blood gases made easy ausmed. Components of the arterial blood gas the arterial blood gas provides the following values. Given that this can be difficult, there is a need for a simple algorithm for systematically handling each of the numbers in turn, as discussed below. Arterial blood gas abg interpretation for medical students, osces and mrcp. Each hemoglobin molecule contains four atoms of iron and therefore can combine with four molecules of oxygen. The paramedics arrived after 10 minutes, during which cpr had not been attempted. Specific recommendations of the working group are labelled by the boxes.
Arterial blood gas analysis and acidbase balance disorders. Pdf arterial blood gas is an important routine investigation to monitor the acid base balance of patients, effectiveness of gas exchange, and the. Arterial blood provides more information than venous blood with regard to acidbase and oxygenation status. As a result, arterial hypoxemia at rest is, by itself, not evidence of severe impairment in exercise tolerance. High paco2, moderately low pao2 and acidic ph indicate. Abg interpretation a guide to understanding abgs geeky medics. Thus, will be impaired in lung disease such as copd.
Arterial blood gas abg interpretation for medical students, osces. Interpreting and using the arterial blood gas analysis. Assess oxygenation arterial oxygen tension pao2 is the partial pressure of oxygen in arterial blood. Disorders of acid base balance can complicate many disease states and occasionally the abnormality may be so severe. The following sixstep process helps ensure a complete interpretation of every abg. Arterial blood gas analysis is not used for impairment rating purposes on a routine basis. Arterial blood gas analysis assesses a patients partial pressure of oxygen pao2, providing information on the oxygenation status. Once youve mastered this technique, youll be doing actual abg interpretation. Blood gas values mixed venous gases measures oxygen left in the blood as it returns to the heart right side after it has been pumped around the body supplying cells with oxygen. For example, they are used to guide the adjustment of ventilator parameters on. We may be presented increasingly with venous blood gases 2. The objective of this work is to describe changes in arterial. Pdf arterial blood gases abg results reflect underlying pathology and interpretation of the results are often compounded by ongoing.
The real value of an abg comes from its ability to provide a. Resting arterial p o 2 does not correlate with exercise capacity. Arterial blood gas analysis is a frequently used and extremely useful clinical tool. Differences are subtle but important on venous gas. Monitoring of acidbase balance is done by testing patients arterial blood gases abgs. However, the more complicated and in some ways more important part of abg analysis is ph regulation. An abg can be used to assess respiratory compromise, status peri or postcardiopulmonary arrest, and medical conditions that cause metabolic abnormalities such as sepsis, diabetic ketoacidosis.
Venous blood gases can provide information on acidbase status and ventilation i. Sample types used for bga different sample types can be used for blood gas measurement arterial blood, arterialized capillary. Arterial blood gas subinternship in critical care medicine. Interpreting an arterial blood gas abg is a crucial skill for physicians, nurses, respiratory therapists, and other health care personnel. Abg interpretation is especially important in critically ill patients.
Arterial blood gas case questions and answers in the space that follows you will find a series of cases that include arterial blood gases. The present article is an attempt for the simplified approach for the bedside interpretation of abg. Here is a series of clinical cases involving patients and arterial. Arterial blood gas determinations of pco2 provide the most accurate determinations of the adequacy of alveolar ventilation, but capillary, transcutaneous, and end tidal techniques are also useful. If it outside range, then it is uncompensated or partially compensated. This tictactoe technique involves a few charts to help you visualize abgs. Arterial blood gas abg analysis linkedin slideshare. A primer on arterial blood gas analysis is a tutorial on how to interpret the results of arterial blood gas testing written by andrew m.
Find out when you get it and what the results mean. Analysis of arterial blood gases a comprehensive approach. But it is often encountered that many students dont know how to read abg, and thats why we are providing arterial blood gas. The chinese university of hong kong sampling of arterial blood for blood gas analysis will yield information on. Arterial blood gas analysis workshop page 4 of 8 arterial blood gas analysis workshop scenario 1 initial information a 75 year old man presents to the accident and emergency department after a witnessed out of hospital vf cardiac arrest. Therefore, a basic understanding of how to interpret abg results can be useful for pharmacists to help them clarify the clinical picture. Scribd is the worlds largest social reading and publishing site. When the ph is normal, it will be fully compensated. How to interpret arterial blood gas results correspondence. It provides a measure of oxygen diffusion across the alveoli into the blood.