Chapter 15 Assessment of Oxygenation and Ventilation

Question 1

The Rate required to stabilize the elimination of mechanically generated CO2.

Answer 1

24 to 30 breaths/min in the pediatric population.
-Rates greater than 30 can indicate respiratory distress.

Question 2

Color

Answer 2

-The color of the skin or the nail beds can reveal much about oxygen transport.
-Pale or ashen color is present in hypotensive states

Question 3

WOB/ Dyspnea

Answer 3

Can be caused by pain or V/Q mismatch
-Accessory muscle use
-Intercostal Thoracic retractions
-Tachypnea
-Tachycardia

Question 4

Breath sounds

Answer 4

-The presence of air over the lung fields is indicative of normal breathing.
-Diminished breath sounds can indicate low PaO2.
-Poor aeration, crackles and rhonchi can indicate a V/Q mismatch
-Chest x-ray would need to be performed.

Question 5

Tactile Fremitus

Answer 5

Chest consolidation is evaluated by vibrations and is assessed by placing the hand on the back and evaluating the presence of congestion.

Question 6

Indications for an ABG on a neonate

Answer 6

1. A neonate showing signs of respiratory distress Nasal flaring, grunting and retractions.
2. An unexplainable change in the patient’s status
3. An ABG should be obtained within 15 to 30 minutes of ventilator changes.
   4.

Question 7

Indications for an ABG on a Pediatric Patient

Answer 7

Same as adults

Question 8

The 2 primary sources of arterial blood sampling on a neonate.

Answer 8

UAC and the Radial artery

Question 9

Other sites that are more difficult to puncture and should only be used if the radial site is contraindicated.

Answer 9

-Brachial
-Dorsalis Pedis
-Posterior tibial

Question 10

Capillary

Answer 10

Capillary blood is another source but is not arterial but a mixture of arterial and venous blood.

Question 11

UAC

Answer 11

The UAC is a preferred method because it causes no pain to the neonate and blood is easily obtained through the catheter.

Question 12

Right to left shunt through the PDA

Answer 12

If a right to left shunt is suspected through the PDA, a right radial arterial sample should be obtained simultaneously with the UAC to compare the pressure of oxygen in each sample.
In the presence of a shunt, will reflect a higher oxygen tension than the post ductal location of the UAC.

Question 13

Transcutaneous monitor

Answer 13

A method to detect a right to left ductal shunt. The PaO2 monitor on the chest will read a higher PaO2 in the upper right quadrant of the chest than the abdomen. This would indicate a right to left ductal shunt. A relative uniformity would rule out a right to left shunt.

Question 14

Problems associated with the UAC

Answer 14

-Rarely stay in place longer than 3 to 4 weeks due to clot formation and infection.
-Thromboembolism
-Hypertension
-Hemorrhage
-Vessel performation
-NEC

Question 15

Reinjection of blood

Answer 15

Air bubbles must be removed by first flicking the stop cock with a finger then slowly drawing back blood into the syringe, drawing out any air.
The blood is now slowly reinjected into the UAC.

Question 16

Radial Artery Catheter

Answer 16

-Accessible when the UAC must be pulled out or has lost its
accessibility.
-Reflects preductal flow

Question 17

Arterial puncture Complications

Answer 17

-Nerve damage
-Infection
-Bleeding
-Embolism
-Hematoma

Question 18

Capillary Samples

Answer 18

Arterialized samples are used when the UAC has been removed and the patient requires ongoing blood gas monitoring.
-Are less hazardous than radial and easily obtainable
-Useful in assessing pH and PaCO2 but not the PaO2
-Heel sticks are as reliable in assessing arterial
-There are no defined normal values capillary values

Question 19

Capillary Sampling

Answer 19

-The most reliable results from the arterialized capillary sample is when the heel is warmed to the same temperature for each stick. (5 to 7 mins)
-The proper technique is used.

Question 20

Complications of Capillary Sampling

Answer 20

-Related to improper procedure
-Osteomyelitis or bone spurs if the calcaneus bone is punctured
-Infection
-Burns
-Hematoma
-Nerve damage
-Bruising
-Scarring

Question 21

PaO2

Answer 21

Neonatal safe range: 50 to 70
Pediatric Normal: 80 to 100 (sea level) and 55 to 80 (5000 ft)
-With a normal oxygen dissociation curve of PaO2 of 60 equals a saturation of 90.
-Low PaO2 in the blood is called hypoxemia and the body’s compensatory mechanism is to increase the RR and the HR.
-The majority is of oxygen is carried by binding to oxygen.

Question 22

PaCO2

Answer 22

Safe Range (Pediatric and Neonatal): 35 to 45
(Chronic Disease): Above 60
-A PaCO2 greater than 45 usually indicates hypoventilation
-A PaCO2 greater than 60 indicates respiratory failure.

Question 23

Determinants of PaCO2

Answer 23

-Alveolar ventilation is determined by minute ventilation minus dead space
-Minute ventilation is the total gas moved into the lungs in one minute. RR X VT
-

Question 24

Dead Space

Answer 24

VD is composed of the following:
-Gas occupying the oral passages
-Gas occupying the nasal passages
-Gas occupying the pharyngeal passages
-ET tube
-Trachea down to the res. bronchioles
-Vented alveoli not perfused by blood

Question 25

pH

Answer 25

Neo and Ped safe range: (7.35 to 7.45)
Acceptable range: (7.30 to 7.50)
-The pH in the blood is a direct result of the number of hydrogen ions present.
-As the pH becomes more acidic or alkalotic, the pH either increases or decreases.

Question 26

HCO3

Answer 26

-The level of bicarbonate in the blood is controlled by tissue metabolism and the function of the kidneys.
-Hydrogen and bicarbonate combine to form carbonic acid