abgs Flashcards
(7 cards)
do ___ need consent for ABG but need consent for _________. If need multiple puncture consider ________.
do not need consent for ABG but need consent for indwelling catheter. If need multiple puncture- consider catheter.
Indications
- Identification and monitoring of acid-base disturbances
- Measurement of the partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2)
- Assess response to interventions (eg, insulin in patients with diabetic ketoacidosis, intubated pts)
- Measure levels of abnormal hemoglobins (eg, carboxyhemoglobin and methemoglobin)
- Procurement of a blood sample in an acute emergency setting when venous sampling is not feasible (most tests can be performed from an arterial sample)
Contraindications and difficulties/limitations
- An abnormal modified Allen’s test -> look for new site
- Local infection, thrombus
- distorted anatomy at the puncture site (eg, previous surgical interventions, congenital or acquired malformations, burns, aneurysm, stent, arteriovenous fistula, vascular graft)
- Severe peripheral vascular disease of the artery
- Active Raynaud syndrome at the sampling site
Difficulties and limitations:
* Pts with tremor, contracted, obesity, hx of shock, edema.
* When you lose landmarks, try ultrasound.
*
Site selection
- Radial, brachial, femoral, axillary, dorsalis pedis
- Supinate wrist, tape wrist in extension with roll under wrist
- Avoid over extension, could make it harder to feel pulse
- Ensure collateral circulation- modified allen’s test
*
Post procedure
- Pressure for 5 minutes (for pt with normal coags)
- Pressure longer if abnormal coags
- Do not check on incision site while holding pressure
- Apply dressing
*
Complications: common, less common and rare
- Common->Local pain and paresthesia, Bruising, Local minor bleeding
- Less common->Vasovagal response, Local hematoma from moderate or major bleeding, Artery vasospasm
- Rare complications-> Infection at the puncture site, Arterial occlusion from a local hematoma, Air or thrombus embolism, Local anesthetic anaphylactic reaction, Local nerve injury, Needle stick injury to health care personnel (limited due to use of ABG kits), Pseudoaneurysm formation, Vessel laceration
Venous Blood Gas: what are they and when are they useful
-VBGs can assess the venous CO2tension (PvCO2) and pH, but they cannot accurately assess oxygenation.
-Need pulse oximetry for O2 status
VBG analysis may be useful in the following:
-Serial ABG monitoring without an arterial line
-Daily assessment to inform ventilator changes
-Acute kidney injury
-ABG refusal
-ABG cannot be obtained
