MIDTERM 1 Flashcards
Arterial blood gas
Primary method for evaluating oxygenation/ventilation and acid-base status (respiratory and metabolic abnormalities). Provides snapshot of that moment in time and good trend information. includes PaO2, PaCO2, HCO3, pH
Clinical indications for drawing ABG
Change in LOC
New dyspnea
Falling BP
Drop in CO2 in chemistry
PaO2 formula for “lower limit” in older adult
80 - (years over 60)
PaO2 requiring intubation
< 50
Oxygen titration
5-10% every hour
Too much oxygen causes…
alveolar damage
Oxygen delivery choice for SEVERE respiratory acidosis
BIPAP or intubation
Oxygen delivery choice for mild-moderate respiratory acidosis
encourage deep breathing
Intervention for respiratory alkalosis
slow down breathing
PaO2 definition
pressure of oxygen dissolved in plasma
pH definition
concentration of H+ in plasma
PaCO2 definition
pressure of CO2 (as a GAS) dissolved in plasma
Base excess
amount of ACID required to restore a LITER of blood to normal pH at a PaCO2 at 40 mmHg
High (positive) base excess in METABOLIC ALKALOSIS
Low (negative) base excess in METABOLIC ACIDOSIS
Classic symptoms of alkalosis
agitation, anxiety, change in LOC
Classic symptoms of acidosis
lethargic, change in LOC
Causes, manifestations, and interventions: Respiratory Acidosis
Low pH
High PaCO2
Cause: hypoventilation
Due to: opioids, head injury (CNS impairment), lung obstruction/disease, chest wall dysfunction (e.g. flail chest)
Early S/S: fatigue, flushed skin, irritability
Late S/S: lethargy, confusion, and somnolence
Tx: increased respiratory rate and depth, naloxone, mobility, repositioning
O2: BIPAP, intibation if unable to breath off themselves
Causes, manifestations, and interventions: Respiratory Alkalosis
High pH
Low PaCO2
Cause: hyperventilation
Due to: arterial hypoxemia, inc. metabolic or HEPATIC failure, mechanical ventilation
Manifestations: anxiety, CNS and peripheral NS irritability
Tx: anxiety medications (if it’s the cause), sloooow breathing
Causes, manifestations, and interventions: Metabolic Acidosis
Low pH
Low HCO3
Loss of base or gain of acid
Causes: diarrhea (secretes HCO3), fistulas, loss of BILE or PANCREATIC juice
More causes: ketoacidosis, lactic acidosis, drugs, TPN, renal failure (less H+ is secreted out the body)
Manifestations: CNS depression, weakness, confusion –> delirium, stupor, respiratory depression, Kussmaul respirations
Tx: treat the underlying problem, replace HCO3 and monitor K+
Causes, manifestations, and interventions: Metabolic Alkalosis
High pH
High HCO3
Cause: gain of base or loss of acid
Due to: diuretics, antacids, GI vomit/suctioning
Manifestations: CNS or PNS irritability (numbness, tingling), cramps, tetany, disorientation –> late symptom is lethargy
Tx: monitor chemistry and remove source
Uncompensated
Abnormal pH, abnormal and normal PaCO2 or HCO3
Partially compensated
Abnormal everything
Compensated
Normal pH, abnormal HCO3 and PaCO2
Respirations are monitored in the CNS by the
medulla oblongata
Why would someone with anxiety who is breathing rapidly want to breath into .a bag?
Anxiety –> rapid breathing –> loss of CO2 –> Respiratory alkalosis
Breathing into a bag = rebreathing CO2
Where would you find TOTAL CO2 content?
Chemistry labs
Normal serum CO2 levels
22-24
Explain the buffer system of the kidneys in relation to CO2 and HCO3
CO2 serum level reflects buffering status of kidneys
- Lower serum CO2 = HCO3 being used to buffer acids
- Kidneys PULL the CO2 in serum to create HCO3
- If CO2 drops in chemistry, indication that you should get an ABG
- Low serum CO2 reflects metabolic acidosis (HCO3 is created and RELEASES H+ into the BLOOD!)
Body buffering system: CO2 + H2O <> H2CO3 <> H+ + HCO3
Relation between COPD and kidney issues in balancing pH
COPD pt used to high CO2, kidneys work overtime to balance pH with HCO3
People with both kidney issues and COPD will have hard time balancing
Someone on dialysis will have a harder time making HCO3
Explain the affinity of O2 when pH is <7.35 and >7.45
Acidosis: affinity to O2 is lost and more O2 will unload to tissues
Alkalotic: affinity increases and cannot unload to tissues
reason why it is “better” to be acidodic than alkalotic
Hypoxemia
Less O2 in blood
Hypoxia
Less O2 to the tissues
looks at function and organ perfusion problems
Oxygen extraction fraction (OEF)
the ratio of bloodoxygenthat a tissue takes from the blood flow to maintain function and morphological integrity. OEF reflects the efficiency ofoxygen utilization by the tissue and, therefore, is a hemodynamic measure in brain ischemia.
Normal: 25%
Saturation Venous Oxygen (SvO2)
percentage of oxygen bound to hemoglobin in blood returning to the right side of the heart. This reflects the amount of oxygen “left over” after the tissues remove what they need.
Normal: 75%
Lower values indicate greater need for extraction (ex: infection, pain)
Higher values indicate inability to extract (ex: microclots, SEPSIS)
Nursing responsibilities in worsening WOB/LOC
HOLY TRINITY OF LABS:
Hgb/Hct, CXR, ABG
Always start the assessment with the patient
Normal range of base excess
-2 mEq to +2 mEq
Nursing interventions for PaO2…
<80
<60
<50
<80- oxygenation
<60- call physician STAT
<50- physician evaluation for intubation
IOM QSEN & quality dimensions in healthcare
Quality and Safety Education for Nurses
6 Dimensions: SQ PT IE Safe Quality improvement (fall precautions, med. rights...) Patient centered Teamwork Informatice Evidence Based Practice
Which nursing process helps more in acute care and why?
DIKW: Data Information Knowledge & Wisdom
Works better in the care of complex patients than ADOPIE
Look at nursing assessments, progress notes… take all of that data and turn it into information & act on it
Reevaluating = wisdom. What worked? What didn’t?
Quality management activities: Measurement, Assessment, Improvement
Measurement (x pts develops CAUTI)
Assessment (reasons why those pts develop CAUTI)
Improvement (can we lower the rate of CAUTI?)
3 resources of legal and ethical standards for nurses
nurse practice act (guides practice by state)
ANA code of ethics (accurate information & privacy)
Critical care standards (decision making skills, critical thinking)
Define respiratory failure
Inability for the body to meet tissue O2 need or CO2 removal either by hypoxia or hypercapnia
Name some causes for hypoxia-related respiratory failure
PE ARDS Drowning Pulmonary edema Lung tumors
Things that prevent O2 from entering or normal gas exchange (ALVEOLAR/CAPILLARY MEMBRANE ISSUE)
Name some causes for hypercapnia-related respiratory failure
CNS depression COPD asthma CF MS muscular dystrophy Guillain-barre
CNS/PNS depression leading to air trapping
Lab data you would find in respiratory failure: how is it diagnosed?
Diagnosed by ABG
PaO2 <50 OR PaCO2 >50 on RA
Check pain, anxiety, CXR, H/H
What lab data would you look at with a patient with COPD experiencing respiratory failure?
pH
Ventilation/Perfusion
1:1 ratio
The vol of blood perfusing the lungs/min is 4-5 L and is approx. equal to the volume of gas that reaches the alveoli /min.
High V/Q
blood flow issue (PE, hypovolemia)
Low V/Q
Possible causes:
Alveoli issue collapsed, blocked, or filled with fluid (COPD, PNA, asthma) which leads to decreased gas entering the bloodstream
Pore of Kohn
If a pore of Kohn in alveoli is blocked by mucus, encourage deep breathing/IS to recruit the blocked alveoli.
Pore of Kohn is a backup mechanism that can pop open and perfuse the alveoli next to them. Reason why IS is great for preventing complications
