ARTERIAL BLOOD GAS

When the needle must be withdrawn completely from the site during ABG, what should you need?

Fresh blood gas kit

Modified Allen Test

In addition, prior radial artery cannulation, severe circulatory insufficiency, wrist or hand burns, or jaundice makes interpreting the results difficult

if the clinicians gets only a small spurt of blood

Slowly withdraw the needle until a pulsatile flow fills the syringe

To ensure a steady state, this may be necessary before sampling and analyzing the blood gases of a critically ill patient.

- waiting up to 30 minutes after any major change in ventilatory support

Healthy individuals breathe air that contains

-Affixed O2concentration (21%) -Negligible amounts of CO2 (approximately 0.2%)

Indications for Arterial Blood Gas Analysis

-evaluate ventilation, oxygenation and the oxygen-carrying capacity of blood (ABG values) - assess the patient's response to therapy or diagnostic tests - -monitor the severity and progression of a documented disease process

point-of-care (bedside) analyzers tend to require less blood ___________ than laboratory analyzers.

- (≤0.5 ml)

a device that provides the important data to the clinician in real time

- . A monitor

In most cases, a sample volume of_________________of blood is adequate

- 0.5 to 1 ml of blood

discard sample if

- >60 minutes has passed

What is recommended when you only get a small spurt of blood while performing a percutaneous needle puncture of the radial artery? A. Slowly withdraw the needle until a pulsatile flow fills the syringe B. Do nothing, wait at that spot C. Discontinue the procedure

- A. Slowly withdraw the needle until a pulsatile flow fills the syringe

Capillary blood gas sampling is indicated when

- ABG analysis is indicated, but arterial access is unavailable - Noninvasive monitoring readings are abnormal - Assessment of initiation, administration, or change in therapy is indicated - A change in patient status is detected by history or physical assessment - Monitoring the severity and progression of a documented disease process is desirable

why femoral punctures should not be performed outside the hospital?

- Because of the need for monitoring the femoral puncture site for an extended period

is used as an alternative to direct arterial access in infants and small children.

- Capillary blood gas sampling

Types of Non-invasive

- Capnometry and Capnography - Pulse Oximetry SpO2 : O2 saturation measured by pulse oximetry 3) Transcutaneous blood gas monitoring (neonatal and pediatric) tcCO2: transcutaneous CO2

an alternative site should be selected.

- If there is evidence of infection or peripheral vascular disease involving the selected limb

Capillary punctures should not be performed

- On patients less than 24 hours old (because of poor peripheral perfusion - When there is a need for direct analysis of oxygenation - When there is a need for direct analysis of arterial blood

Relative contraindications include

- Peripheral vasoconstriction - Polycythemia (caused by shorter clotting times) - Hypotension

True of False Insert the needle, bevel up, through the skin at a 45 degree angle until blood pulsates into the syringe.

- True

True or false: The need to use syringe suctioning while obtaining an arterial blood sample indicates venous admixture.

- True

Arterial puncture should not be performed through

- a lesion or distal to a surgical shunt

Inspect the sample for obvious signs of preanalytic error

- air bubbles, - gross dilution, - clotting, - air exposure

Warming the skin to

- approximately 42°C

capillary PO2 is of little value in estimating

- arterial oxygenation

What is the traditional method used to avoid pre-analytic errors caused by blood cell metabolism?

- chill the sample quickly by placing it in ice

The clinician should use the analyzer to measure a patient's FiO2 only after

- confirming both reading.

why we Mix the sample?

- critical for hemoglobin and hematocrit measurements

what do you need to document?

- date, time, and site of sampling; - results of the modified Allen test - patient's body temperature, position, activity level, and respiratory rate; and - FiO2 concentration

Clinicians can avoid most pre-analytic errors by

- ensuring samples obtained anaerobically - properly anticoagulated - quickly analyzed

Needle is never redirected without

- first being withdrawn to the subcutaneous tissue.

Clinical focus is on

- gas exchange between the lungs and blood or between the blood and tissues

most common site for sampling, specifically the lateral aspect of the plantar surface

- heel

Capillary samples or heel sticks

- heel sticks

Abnormal results of a modified Allen test (lack of collateral circulation) may be indicative of

- inadequate blood supply to the hand and suggest the need to select another puncture site

Invasive procedures require

- insertion of a sensor or collection device into the body

Monitoring can be either

- invasive - noninvasive.

noninvasive monitoring .

- is a means of gathering data externally

How do we introduce the sample?

- manually - automatic aspiration

Invasive procedures tend to provide

- more accurate data - but they carry greater risk.

Most point-of-care (bedside), analyzer systems require that the sample

- not be chilled - be analyzed within 1 to 2 minutes after being obtained, depending on the manufacturer

Monitoring is an

- ongoing process by which clinicians obtain and evaluate dynamic physiologic processes in a timely manner

is the recommended site for capillary puncture specimens in infants younger than 1 month old to avoid nerve and bone damage

- posterior medial or lateral curvature of the heel

should include both scheduled parts replacement and routine operational testing

- preventive maintenance

Galvanic cells are particularly sensitive to condensation. The clinician should place the analyzer sensor

- proximal to any humidification device

Is the preferred site for arterial blood sampling

- radial artery

brachial, femoral, and dorsalis pedis are riskier

- should be used only by clinicians specifically trained in their use.

Hypoxemic patients are routinely given supplemental O2

- supplemental O2

The actual sample volume needed depends on

- the anticoagulant used, - the requirements of the specific analyzer used, and - whether other tests will be performed on the sample

when drawing arterial blood from hypotensive patients or when using small needles (<23-gauge),

- the clinician may need to pull gently on the syringe barrel

Laboratory analysis refers to

- to discrete measurements of fluids or tissue that must be removed from the body.

Point-of-care testing reduces

- turnaround time

adult children and infants

20-gauge to 22-gauge 23 guage to 25 guage

If a patient was running prior to an ABG draw, how long should they wait before taking the sample, (they are healthy)?

5 minutes

If a sensor or electrode depletes and you get inconsistent readings on the O2 sensor, you should? A. Change the sensor or electrode B. Purchase a new O2 analyzer device C. Proceed with using this O2 analyzer

A. Change the sensor or electrode

Which O2 analyzer needs batteries or external power? A. Galvanic cell B. Polarographic (Clark) electrode

A. Galvanic cell

Which one is an indication of capillary blood gas sampling? A. On patients less than 24 hours old B. ABG analysis is indicated, but arterial access is unavailable C. A need for direct analysis of arterial blood

B. ABG analysis is indicated, but arterial access is unavailable

To calibrate both O2 analyzers, you should? A. Expose the sensor to 75% O2, adjust balance, and then room air 21% within (+/-2%) B. Expose the sensor to 100% O2, adjust balance, and then room air 21% within (+/-2%) C. Expose the sensor to 90% O2, adjust balance, and then room air 21% within (+/-2%)

B. Expose the sensor to 100% O2, adjust balance, and then room air 21% within (+/-2%)

Which O2 analyzer has a response time of 10 to 30 seconds? A. Galvanic cell B. Polarographic (Clark) electrode

B. Polarographic (Clark) electrode

Which is the preferred site for arterial blood sampling? A. Dorsalis pedis B. Radial artery C. Brachial artery D. Femoral artery E. Ulnar artery

B. Radial Artery

Which is the near the surface and relatively easy to palpate and stabilize? A. Dorsalis pedis B. Radial artery C. Brachial artery D. Femoral artery E. Ulnar artery

B. Radial artery

Where is the most common site for capillary puncture of an infant? A. Tip of any forefinger B. Inner thigh or either leg C. Lateral aspect of the heel's plantar surface D. Back of either hand

C. Lateral aspect of the heel's plantar surface

All of the following are indications of arterial blood gas sampling EXCEPT: A. The need to monitor the severity and progression of documented disease process B. The need to evaluate ventilation, acid-base balance, oxygen status, and oxygen-carrying capacity of blood C. The need to fulfill routine blood samples with every patient D. The need to assess the patient's response to therapy or diagnostic tests

C. The need to fulfill routine blood samples with every patient

if pain or anxiety to the procedure exists (needle insertion)

Consider local anesthetic for subsequent sampling attempts

All of the following should be monitored during arterial blood puncture except: A. Pulsatile blood return B. Puncture site (for hematoma) after pressure dressing C. Presence of air bubbles or clots in the syringe D. Barometric pressure

D. Barometric pressure

Which are important to document during ABG procedures?

Date, time and site of sampling results of Allen test - pt's body temperature, position, activity level, and respiratory rate - FIO2

Capillary punctures should not be performed at or through the following? A. The fingers of neonates B. Inflamed, swollen, or edematous tissues C. Localized areas of infection D. Previous puncture sites E. All of the above

E. All of the above

Which of the following should be checked in the patient chart before performing an arterial puncture A. Primary diagnosis and history B. Presence of bleeding disorders or blood-borne infections C. Anticoagulant or thrombolytic drug prescriptions D. Respiratory care orders E. All of the above

E. All of the above

The radial artery is the preferred site for arterial blood sampling for the following reasons:

It is near the surface and relatively easy to palpate and stabilize. • Effective collateral circulation normally exists in the ulnar artery. • The artery is not near any large veins

True or false: Arterial blood gas sampling is used to measure O2 and CO2 in the blood before the blood reaches the tissues

True

True or False When changing vent setting, do we wait 30 minutes on a critically ill pt or everyone?

True If intubated, everyone

Samples that have been stored for an undetermined time, whether chilled or not, should be

discarded.

Patients with healthy lungs achieve a steady state ___________ after changes

in only 5 minutes

What does do not handle a needle using both hands mean?

one hand is needed to hold the skin or marking area

patients with chronic obstructive pulmonary disease (COPD) may require __________________minutes

up to 30 minutes

Precautions/Possible Complications for Arterial Blood Gas Analysis

•Arteriospasm •Hemorrhage •Air or clotted blood emboli (Embolization) •Trauma to the vessel •Anaphylaxis from local anesthetic •Arterial occlusion •Patient or sampler contamination (Infection) •Vasovagal response

Examples of indwelling vascular line (used to measure blood pressure)

•Peripheral, Umbilical Artery •Central Vein •Pulmonary Artery

Arterial Puncture (direct measurement of pH, PaCO2, PaO2)

•Radial artery •Brachial artery •Femoral