A discussion of the anion gap, including its calculation and its use in categorizing metabolic acidoses, including multiple examples of acid-base interpretation.
Arterial blood gas (ABG) interpretation is something many medical students find difficult to grasp (we’ve been there). We’ve created this guide, which aims to provide a structured approach to ABG interpretation whilst also increasing your understanding of each results relevance. The real value of an ABG comes from its ability to provide a near immediate reflection of the physiology of your patient, allowing you to recognise and treat pathology more rapidly. To see how to perform an arterial blood gas check out our guide here. If you want to put your ABG interpretation skills to the test, check out our ABG quiz here. Normal ranges pH: 7.35 – 7.45 PaCO2: 4.7-6.0 kPa PaO2: 11-13 kPa HCO3-: 22-26 mEg/L Base excess: -2 to +2 mmol/L Patient’s clinical condition Before getting stuck into the details of the analysis, it’s important to look at the patient’s current clinical status, as this provides essential context to the ABG result. Below are a few examples to demonstrate how important context is when interpreting an ABG. A normal PaO2 in a patient on high flow oxygen – this is abnormal as you would expect the patient to have a PaO2 well above the normal range with this leve
10 arterial blood gas problems worked using the tic-tac-toe method.
Arterial Blood Gas (abg) Analyzer
This analyzer should not substitute for clinical context. Sodium and chloride are required for anion gap calculation. While the analyzer can often help with analysis, the history of the patient is critical for accurate interpretation. NOTE: Normal albumin levels are typically 4 g/dL in US units and 40 g/L in SI units. A venous blood gas often correlates well with arterial blood gas findings (except for PaO2) unless values are extremely abnormal, and can often be used successfully as a screening tool. This tool, developed by Jonathan Chen, MD first determines the primary process by looking at the pH and the PCO2. It then calculates compensations to determine chronicity, compensatory, and co-existing acid-base disturbances. Diabetic Ketoacidosis (check serum ketones) Propylene Glycol (in BZD drips) or Paraldehydes Oxoporin (reflects fatty liver damage from glutathione consumption, e.g. acetaminophen toxicity) Renal Tubular Acidosis (Type 1 Distal or Type 2 Proximal) Jonathan Chen, MD, PhD is a research fellow in medical informatics, based at the Veteran Affairs Hospital in Palo Alto and Stanford University. He completed the Stanford Internal Medicine residency program and was in the
There are two types of compensation to look for in an ABG. If compensation occurs, it is full or partial. If there is no compensation, the ABG is called uncompensated. If there are both respiratory and metabolic primary problems, the ABG is known as mixed or combined. Uncompensated Here the pH is abnormal; it will be either an acidosis or an alkalosis. The pH will always point to the primary problems (acidosis/alkalosis). The nurse then needs to look at the pCO2 or HCO3. In an uncompensated problem, there will be a respiratory acidosis or alkalosis or a metabolic acidosis or alkalosis, but the value that would correct for this, the opposite organ value, will not change as there is no compensation for the problem. ---------- Biology tutoring on Chegg Tutors Learn about Biology terms like Uncompensated Partially Compensated on Chegg Tutors. Work with live, online Biology tutors like Niyati B. who can help you at any moment, whether at 2pm or 2am. Liked the video tutorial? Schedule lessons on-demand or schedule weekly tutoring in advance with tutors like Niyati B. Visit https://www.chegg.com/tutors/Biology-... ---------- About Niyati B., Biology tutor on Chegg Tutors: Kasturba Medical College, Manipal, India, Class of 2013 Medicine major Subjects tutored: Health and Medicine, PSAT (reading), PSAT (math), SAT (reading), Biology, Marathi, Medical Assistant, TOEFL, Basic Math, Hindi, English as a Second Language, SAT (math), and Medicine TEACHING EXPERIENCE I have taught concepts of basic math like solving linear equations to my young cousins in California ( grade 6 ) as well as basic human biology like circulatory system. I used to teach English to the children of the house hold helpers back in India and i find that this is what has helped me develop patience and not just that but also helped me brush up on my own knowledge of some things that I never thought I'd use after middle school. Einstein said if you can't explain it simply then you haven't understood it well enough and I completely agree. My goal: explain it simply, but also in a way that is hard to forget. EXTRACURRICULAR INTERESTS Well in a nutshell I'm a knowledge hungry newbie doctor ( graduated from a medical school in India ) , an avid reader , and I'm also a huge trivia nerd. I have a flair for all things literary ( debate , crosswords , word play you name it ) I absolutely love to read ( mostly fiction , some of my favorite authors like Khaled Hosseini are doctors by profession ) and I have written about 30 poems over the past 10 years. I enjoy listening to podcasts, my favorite one is called Good Job Brain which is a quiz and trivia podcast and I also have a particular fondness for learning about Greek and Roman mythology, and love spoken word poetry. I love to listen to music and sing ( albeit not too well ) and I collect fridge magnets from the places I've been. I have spent part of my childhood in the US, and then the rest in India and my life has been transcontinental for the most part which has given me the benefit of some amazing experiences. I also have an artsy side - sketching and painting are some ways I like to unwind, and listening to TED talks is always an option. Want to book a private lesson with Niyati B.? Message Niyati B. at https://www.chegg.com/tutors/online-t... ---------- Like what you see? Subscribe to Chegg's Youtube Channel: http://bit.ly/1PwMn3k ---------- Visit Chegg.com for purchasing or renting textbooks, getting homework help, finding an online tutor, applying for scholarships and internships, discovering colleges, and more! https://chegg.com ---------- Want more from Chegg? Follow Chegg on social media: http://instagram.com/chegg http://facebook.com/chegg http://twitter.com/chegg
Uncompensated, Partially Compensated, Or Combined Abg Problems
Arterial Blood Gas (ABG) analysis requires in-depth expertise. If the results are not understood right, or are wrongly interpreted, it can result in wrong diagnosis and end up in an inappropriate management of the patient. ABG analysis is carried out when the patient is dealing with the following conditions: • Breathing problems • Lung diseases (asthma, cystic fibrosis, COPD) • Heart failure • Kidney failure ABG reports help in answering the following questions: 1. Is there acidosis or alkalosis? 2. If acidosis is present, whether it is in an uncompensated state, partially compensated state, or in fully compensated state? 3. Whether acidosis is respiratory or metabolic? ABG reports provide the following descriptions: PaCO2 (partial pressure of dissolved CO2 in the blood) and PaO2 (partial pressure of dissolved O2 in the blood) describe the efficiency of exchange of gas in the alveolar level into the blood. Any change in these levels causes changes in the pH. HCO3 (bicarbonate in the blood) maintains the pH of the blood within normal range by compensatory mechanisms, which is either by retaining or increasing HCO3 excretion by the kidney. When PaCO2 increases, HCO3 decreases
Content currently under development Acid-base disorders are a group of conditions characterized by changes in the concentration of hydrogen ions (H+) or bicarbonate (HCO3-), which lead to changes in the arterial blood pH. These conditions can be categorized as acidoses or alkaloses and have a respiratory or metabolic origin, depending on the cause of the imbalance. Diagnosis is made by arterial blood gas (ABG) interpretation. In the setting of me ...
Arterial Blood Gas (ABG) analysis requires in-depth expertise. If the results are not understood right, or are wrongly interpreted, it can result in wrong diagnosis and end up in an inappropriate management of the patient. ABG analysis is carried out when the patient is dealing with the following conditions: • Breathing problems • Lung diseases (asthma, cystic fibrosis, COPD) • Heart failure • Kidney failure ABG reports help in answering ...
(Video) Overview of Buffering and the Henderson-Hasselbalch Equation By James L. Lewis, III, MD, Attending Physician, Brookwood Baptist Health and Saint Vincents Ascension Health, Birmingham Metabolic alkalosis is primary increase in bicarbonate (HCO3) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Common causes include prolonged vomiting, hypovolemia, diuretic use, and hypokalem ...
Respiratory Acidosis Definition Respiratory acidosis is a condition in which a build-up of carbon dioxide in the blood produces a shift in the body's pH balance and causes the body's system to become more acidic. This condition is brought about by a problem either involving the lungs and respiratory system or signals from the brain that control breathing. Description Respiratory acidosis is an acid imbalance in the body caused by a problem relate ...
This analyzer should not substitute for clinical context. Sodium and chloride are required for anion gap calculation. While the analyzer can often help with analysis, the history of the patient is critical for accurate interpretation. NOTE: Normal albumin levels are typically 4 g/dL in US units and 40 g/L in SI units. A venous blood gas often correlates well with arterial blood gas findings (except for PaO2) unless values are extremely abnormal, ...
Step 4: Identify the compensatory process (if one is present) In general, the primary process is followed by a compensatory process, as the body attempts to bring the pH back towards the normal range. If the patient has a primary respiratory acidosis (high PCO2 ) leading to acidemia: the compensatory process is a metabolic alkalosis (rise in the serum bicarbonate). If the patient has a primary respiratory alkalosis (low PCO2 ) leading to alkalemi ...