OBJECTIVES OF OBTAINING ARTERIAL BLOOD GASES 1. Describe the equipment is needed for a given procedure and how it is properly used. a. Arterial Puncture b. Indwelling Catheter c. Capillary Blood Sample Equipment for an ABG stick: Blood gas kit with 2x2 gauze, band-aid, alcohol wipe, antiseptic wipe, etc Gloves,towel to support wrist Equipment for an arterial line draw 10cc syrine with blunt needle, another blunt needle to replace syringe kit needle, 2 alcohol wipes Equipment for a Capillary draw Lance, capillary tube, alcohol wipe, 2x2 gauze, warming cloth 2. Name common arterial puncture sites. The radial is the preferred site. Alternates are brachial and femoral. 3. Describe the standard isolation precautions with an ABG puncture. Univeral precautions, Wearing gloves (Gloves provide little protection from needle punctures but should be worn to prevent splashing of blood on sores or other skin breaks) , wiping area of puncture, disposing of needles in sharps container, preventing inadvertent needle stick to therapists and other health care workers, one hand resheathing or rubber plug capping, transport without needle 4. Describe the contra-indications for arterial puncture. Contraindications are absolute unless specified otherwise. 1. Negative results of a modified Allen test (collateral circulation test) are indicative of inadequate blood supply to the hand' and suggest the need to select another extremity as the site for puncture. 2. Arterial puncture should not be performed through a lesion or through or distal to a surgical shunt (eg, as in a dialysis patient). If there is evidence of infection or peripheral vascular disease involving the selected limb, an alternate site should be selected. 3. Agreement is lacking regarding the puncture sites associated with a lesser likelihood of complications; however, because of the need for monitoring the femoral puncture site for an extended period, femoral punctures should not be performed outside the hospital (usually only by ER doctor). 5.4 A coagulopathy or medium-to-high-dose anticoagulation therapy (eg, heparin or coumadin, streptokinase, and tissue plasminogen activator but not necessarily aspirin) may be a relative contraindication for arterial puncture. 5. List the precautions and/or possible complications. They are 1. Hematoma 2. Arteriospasm 3. Air or clotted-blood emboli 4. Anaphylaxis from local anesthestic 5. Introduction of contagion at sampling site and consequent infection in patient; introduction of contagion to sampler by inadvertent needle 'stick.' 6. Hemorrhage 7. Trauma to the vessel 8. Arterial occlusion – loss of blood flow and circulation 9. Vasovagal response 10. Pain 6. Be able to perform the Allens Test Have patient make a fist while you tightly squeeze both the radial and ulnar arteries; Let go of the ulnar and watch to see if hand is uniformly re-perfused (pinks up). If large areas remain pale - check the other hand. 7. How to obtain blood from an arterial line. A. Gather material (10cc waste syringe, alcohol wipes, blunt tip needle), check order, confirm patient B. Identify the arterial line with: a. Proximal port b. Distal port c. Opening stopcock d. Flush mechanism C. Close the stopcock to allow the art line to occluded – Confirm with monitor check D. With the 10cc syringe, draw from the distal port until blood appears at the port, (Hint - withdraw needle with negative pressure) E. Using a blunt tip in the proximal port, insert and fill the ABG syringe, wipe port/invert F. Open the stopcock and flush the line of blood 8. What are some common errors that contribute to analysis errors? A. Venous puncture a. Occasionally blood is drawn from a vein. Take heart, it happens to everyone and it takes great skill to draw from a vein. B. Delay in processing a. Place the sample on ice. The living tissue (blood) will continue to consume oxygen and nutrients and to produce carbon dioxide. PaCO2 will be elevated. C. Air bubbles in sample a. The room air oxygen can diffuse into the sample and cause an increase in PaO2. If the PaO2 is greater than 160 it will decrease the in the sample. The carbon dioxide will diffuse out and decreased the PaCO2. 9. What are the normal values expected from an ABG? Arterial blood – pH 7.40, PaCO2 40, PaO2 80-100 Venous blood - pH 7.45, PaCO2 45, PaO2 40 Alveolar partial pressures Cellular partial pressures VOCABULARY Anti-coagulants (Rau Page 327-331) A drug that thins the blood and prevents quick clotting times. Typical in heart patients. Measured with PT and PTT. Once-a-day aspirin could be considered. Example Heparin, warfarin, and comindin Arterial blood Blood in the arteries. It is brighter red color, has a higher oxygen level, a higher carbondioxide level, and a less acidotic pH Collateral circulation A secondary (back road – ‘detour’ of backup circulation- like I-5 and Hwy 99). Invasive Within the body, as apposed to pulse oximetry values can be obtained non-invasively Thrombolytic A drug that causes the clot to break up. A suspected heart attack patients in ER get these. It is called tPA protocol. Example: Streptokinase Thrombosis An abnormal condition where a thrombus (clot) develops in the blood stream and obstructs the flow, sometimes with dire consequences.