A&D ch. 8,10

arterial blood O2 and CO2 levels reflect what?

• oxygen and carbon dioxide levels in the lungs
• lung function

Match the type of hypoxemia

• diffusion defect

• blood flows back from alveoli that are not ventilated, does not pick up oxygen (ateletasis, pneumonia, pulmonary edema, ARDS)

• V/Q mismatch

• decreased Pio2 lowers PAO2 (low partial pressure) altitude sickness

• low Pio2

• rise in PaCO2

  decrease in PaO2

  (drug overdose, neuromuscular)

• pulmonary shunting

• impaired gas transfer across alveolar-capillary membrane (fibrosis)

• hypoventilation

• blood flows through hypoventilated regions of the lung (COPD, Asthma)

this type of analysis is helpful to guide treatment

• arterial blood gas O2 and CO2 levels

• pulse oximetery

what does mixed venous blood reflect?

• tissue conditions

• White blood cell count and platelet count

why are peripheral venous samples of no value?

• Peripheral venous samples are contaminated with bacteria.
• Peripheral venous samples do not accurately reflect arterial blood composition.

  -hit the vein not artery

Match the following

• pH

• alkaline<35-45>acid, anything higher than 45 mixes with water and makes carbonic acid

• HCO3-

• acid<22-26>alkaline

• PaO2

• 80-100

• PaCO2

• (acid) <7.35-7.45> (alkaline)

what happens when the arterial pressure (Pa) of CO2 is greater than 45?

why is this bad?

• Hypoxia
• anything higher than 45 mixes with water and forms carbonic acid

  Hypercapnia

pulse oximetry reduces the need for ABGs but does not reflect what?

• CO2 levels or acid base status

• accurate readings

steps prior to arterial blood sampling

1)chart review (medications that thin the blood, platelet levels)

2)check blood clotting ability

3)whether they have had surgeries in the past

• 1,2

• 1,3

why would you check a patients blood clotting ability prior to an ABG?

• To check for signs of infection and determine the patient's blood type.

• To assess the risk of bleeding during the procedure.

  • - low platelets/increased bleeding time indicates longer post-puncture pressure to be applied.