Arterial blood gas interpretation

The presence of these acid anions, which are not measured, will cause an increase in the anion gap. When underventilation occurs, for what ever reason eg muscular weakness or opiate overdosethe PaCO2 will increase the definition of underventilation and PaO2 must decrease even if the lungs are perfectly healthy.

An Arterial Blood Gas requires the nurse to collect a small sample of blood - generally a minimum of 0. Box 1 provides an example of a patient presenting with breathlessness, where ABGs form an important diagnostic test.

The kidneys only partially compensate, so the patient may still have a low blood pH, i.

Interpretation of arterial blood gas

Since the pH is acidotic and the CO2 also acidotic, then you have respiratory acidosis. Base excess BE measures all bases, not just bicarbonate.

You don't have to look at any other values. If a plastic blood gas syringe is used, the sample should be transported and kept at room temperature and analyzed within 30 min. These results are usually available for interpretation within five minutes. Both the pH-stat and alpha-stat strategies have theoretical disadvantages.

The acid-base balance of the blood is maintained by two areas of the body: The goal is to maintain a pH of 7.

What you have here is a case of uncompensated combined acidosis. A secondary compensatory process can be readily identified because it opposes the observed deviation in blood pH. The most common causes of normal anion gap acidosis are GI or renal bicarbonate loss and impaired renal acid excretion.

The lower pH represents acidosis and the higher pH represents alkalosis with the normal range of pH from 7. If a sample is to be taken from the femoral artery the patient is supine with the leg in a neutral position.

These results are usually available for interpretation within five minutes. Type 2 respiratory failure results from underventilation, which can occur even in the context of healthy lungs.

Base excess

In summary, the kidneys partially compensate for respiratory acidosis by raising blood bicarbonate. The goal is to maintain the arterial carbon dioxide tension at 5. You need to go no further in analyzing this ABG.

The needle is inserted at a 45 degree angle aiming at the artery with the needle bevel facing upwards. A respiratory acidosis with a low sHCO3 would indicate a combined respiratory and metabolic -acidosis. Cobas b - Roche Diagnostics The machine used for analysis aspirates this blood from the syringe and measures the pH and the partial pressures of oxygen and carbon dioxide.

By increasing the cerebral blood flow beyond the metabolic requirements, the pH-stat method may lead to cerebral microembolisation and intracranial hypertension. Is it acidotic or alkalotic? Well, the pH is outside the normal range of 7. Now, had the HCO3 in this example been on the alkalotic side of its normal range say 27 this ABG would have been partially uncompensated.

Thus, you have uncompensated metabolic alkalosis. For those at risk for bleeding, pressure may need to be held for longer periods of time. You also must note the following: Afterwards, an adhesive dressing should be placed over the puncture site.

This will be discussed further below. Both systems are primarily concerned with keeping blood pH in the normal range. Is is compensated or uncompensated? You can use PowerShow. This framework is depicted in Figure 1. Blood can also be taken from an arterial catheter already placed in one of these arteries.

For example, decreased ventilation has a higher value and increased ventilation has a lower value. No, all the numbers are out of the normal range B. Toxins may have acidic metabolites or trigger lactic acidosis.

Since the pH is less than 7. Given that the two conditions result from entirely different mechanisms, with implications for treatment, one should be able to distinguish between them.Blood Gas Analysis® Reviewed October,Expires October, • Describe at least 6 factors that can interfere with arterial blood gas values.

• Describe procedures for obtaining arterial, venous, capillary, and cord blood samples. Correct interpretation of an arterial blood gas (ABG) value can quickly help identify a wide range of illnesses.

Most physicians recall learning the Henderson-Hasselbalch equation and how to calculate pH based on the presence of hydrogen ions. Definition. Arterial blood gas (ABG) analysis evaluates gas exchange in the lungs by measuring the partial pressures of oxygen (PaO2) and carbon dioxide (Paco2) as well as the pH of an arterial sample.

Pao2 measures the pressure exerted by the oxygen dissolved in the blood and evaluates the lungs’ ability to oxygenate the blood. 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.

Arterial blood gases (ABGs) are an important routine investigation to monitor the acid-base balance of patients. [] They may help make a diagnosis, indicate the severity of. An Arterial Blood Gas requires the nurse to collect a small sample of blood - generally a minimum of ml, but a full 1 ml is preferred.

Blood can be drawn via an arterial stick from the wrist, groin, or forearm.

Arterial blood gas interpretation
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