Data Assessment Flashcards
Your patient presents with:
PO2 72
PCO2 44
O2 sat 87%
Is this normal, ventilatory failure, or hypoxia?
Hypoxia
Your patient presents with:
PO2 67
PCO2 59
O2 sat 88%
Is this normal, ventilatory failure, or hypoxia?
Ventilatory failure
Your patient presents with:
PO2 57
PCO2 43
O2 sat 83%
Is this normal, ventilatory failure, or hypoxia?
Hypoxia
Your patient presents with:
PO2 89
PCO2 40
O2 sat 95%
Is this normal, ventilatory failure, or hypoxia?
Normal ABG
What is occurring in Phase I?
Inspiration
- ETCO2 = 0 (baseline)
What is occurring in phase II?
- Start of expiration & starting to clear dead space
What is occurring in phase III?
- Alveolar gas is exchanged
What is occurring in phase IV?
Start of inhalation
What part of the graph is showing up on our monitors?
- D = max ETCO2 = maximum sample of alveolar gas
If C - D is not flat what does that tell the practitioner ?
- V/Q mismatch
- C-D is alveolar gas exchange & is flat in a healthy patient
Alpha angle is normally 100-110 degrees what disease process would cause a widened angle?
- Disease process with a hard time pushing out CO2 = COPD, asthma
Beta angle is normally 90 degrees, what disease process would cause a widen angle?
- Rebreathing = mixture of O2 & CO2
What does this waveform represent?
Normal spontaneously breathing patient
What does this waveform represent?
Normal ventilated patient
What does this waveform represent?
- Rebreathing
- Soda Lyme needing changed
- Insufflation
- Inspiratory & expiratory valve failure
What does this waveform represent?
- Curare Cleft
- Diaphragm movement
- check twitches
- if no twitches — see what the surgeon is doing
What does this waveform represent?
- Esophageal intubation
- Obstructed sampling line
- How do you tell the difference? - blow into the sampling line
What does this waveform represent?
- Cardiogenic oscillations
- Paralyzed patient coming back = rhythmic increase & decrease of intrathoracic pressure
What does this waveform represent?
- Return of spontaneous respirations - asychronized with the vent
What does this waveform represent?
- Shark fin = loss of alpha angle = hallmark sign
- Prolonged expiration
- COPD
- Bronchospasm
- Partial mucous plug
- Upper airway obstruction (FBO)
What does this waveform represent?
- Cuff leak
- Over or under sampling
- Hyperventilation
- Increase dead space = V/Q mismatch
= look at ETCO2 & PCO2 to determine if this is the case
What does this waveform represent?
- Leak in sampling line
- ET diluted - the positive pressure from the vent pushes more CO2 into the line
What do these waveforms represent?
- Both could be faulty inspiratory flutter valve
What does this trend capnogram represent?
- Acute event
- Disconnect from the machine = extubation, circuit popped off
- Total obstruction
- Mucous plug
- Sampling line
What does this trend capnogram represent?
- Cuff leak
- Partial disconnect
- Partial mucous plug
- Cardiac arrest
- Bleeding out
- Passive PE
- Obstruction of major blood vessel - retractor/clamp/sponge
What does this trend capnogram represent ?
- Fixed a kink
- Small embolism with recovery
- Small bronchospasm with recovery
What does this trend capnogram represent ?
- Hypoventilation
- Hyperthermia (anything that increases metabolism)
- Tourniquet release
- CO2 insufflation
What are the normal parameters for pH, HCO3, & PCO2?
- pH 7.35 - 7.45
- HCO3 22 - 27
- pCO2 35 - 45
What is this ABG a sign of:
pH = 7.48
HCO3 = 38
PaCO2 = 53
- Metabolic alkalosis, partially compensated
What is this ABG a sign of:
pH = 7.37
HCO3 = 36
PaCO2 = 65
- Respiratory acidosis, compensated
What is this ABG a sign of:
pH = 7.32
HCO3 = 32
PaCO2 = 65
- Respiratory acidosis, partially compensated
What is this ABG a sign of:
pH = 7.69
HCO3 = 35
PaCO2 = 50
- Metabolic alkalosis, partially compensated
What is the relationship between FiO2 and PaO2?
- P divided by F = P/F ratio
- normal PaO2/FiO2 ratio = 400 - 500 mmHg (~55 - 65 kPa)
- PaO2 should = FiO2 x 500
Ex: PaO2 = 90 on 40% oxygen (FiO2 = 0.40)
90/ 0.40 = 225
(RA = 21% = 0.21; add 4% for every liter increase)
What is base excess or base deficit ?
- Refers to the amount of base in the blood, or the amount of acid required to restore a liter of blood to it’s normal pH at a PaCO2 of 40
- A positive number is called a base excess & indicates metabolic alkalosis
- A negative number is called a base deficit & indicates metabolic acidosis
- Does not take into account respiratory = cannot use as a diagnosis
What is a normal base excess/ deficit?
-2 to +2
What are causes of abnormally negative BE (< -2)
- Excretion or neutralization of HCO3 - in buffering =
- Excess lactic acid - anaerobic metabolism or hypoxia
- Diabetic ketoacidosis = high levels of keto acids
- Sepsis, septic shock, or chronic hypoxia
- Loss of HCO3 from the body
- Diuretics, diarrhea, renal failure
- Failure to regenerate HCO3 by the kidneys = preventing excretion of acids & reabsorption & production of HCO3
- Renal tubular acidosis
- Ingestion of poisons such as methanol, ethylene glycol, or excessive aspirin
What are causes of abnormally positive BE (> +2)
- Usually represents Metabolic alkalosis
- Increased generation or administration of HCO3
- consequent on excessive loss of hydrogen &/or chloride ions
- Vomiting
- Renal overproduction of HCO3 seen in Cushings disease
- Crohn’s disease - messes w/ Cl ions and causes Hypokalemia
What is an Anion gap
- Useful in determining whether a base deficit is caused by addition of acid or loss of bicarbonate
- Base deficit w/ elevated anion gap indicates addition of acid (ketoacidosis)
- Base deficit w/ normal anion gap indicates loss of bicarbonate (diarrhea) - the anion gap is maintained b/c HCO3 is exchanged for chloride during excretion
The law of electrochemical neutrality in the blood requires?
- All positive ions equal to all negative ions in the blood
- In the blood cations (+) are always greater than anions (-)
- The anion gap measures the gap between + and - ions
How do you calculate the Anion gap?
AG (w/o K+) = [Na+] - ([Cl-] + [HCO3-])
AG (w/ K+) = ([Na+] + [K+]) - ([Cl-] + [HCO3-])
What is a normal Anion gap?
10 - 20 mEq/L
(FYI: In practice 3- 10 is normal, & > 10 is almost exclusively the result of increased unmeasured anions derived from metabolic acids- thus metabolic acidosis is the most common cause of a raised anion gap)
Anion gap > 30 mmol/L is usually caused by ?
- Organic acidosis
- KULT acronym
- Keto acidosis
- Uremia
- Lactic acidosis
- Toxins: ethanol, aspirin, Toluene (solvent)
Anion gap < 20 mmol/L indicates what:?
- Rarely indicates a significant acidosis & is most often 2nd to changes in:
- Protein
- Phosphates
- Or change equivalents
What are the 2 electrolytes important in cell function?
- Calcium & Potassium
What does Potassium do for cell function?
- Maintain resting membrane potential
What does Calcium do for cell function?
- Maintain threshold potential
If a potassium imbalance is left undiagnosed & untreated (hypo or hyper) what could happen?
- Significant morbidity & mortality
- Both are medical emergencies and require prompt intervention
Where is majority of K+ excreted GI or renal?
- Major route = excretion in urine
- Minor route = excreted via the GI
Renal regulation of K+ depends on what hormone?
- Aldosterone
- Rising concentration of K+ stimulates aldosterone synthesis & release
= Reduces K+ by increasing renal excretion
What is the most common cause of Hypokalemia (< 3.5)**
- Diuretic therapy:
Thiazides & Loop diuretics
What are 9 other causes of Hypokalemia (< 3.5) other than diuretics?
- Severe/chronic diarrhea/vomiting
- Metabolic alkalosis (K+ moves into the cell)
- Conn’s syndrome (increased aldosterone)
- Tx of DKA (d/t increased loss of K+ in urine)
- Inadequate K+ intake
- Laxative abuse
- Licorice abuse (increases aldosterone levels)
- Beta blocker (K+ moves into cell)
- Insulin overdose (K+ moves into cell)
Symptoms of Mild Hypokalemia (> 3.0)
- Usually asymptomatic
Symptoms of Moderate Hypokalemia (2.6 - 3.0)
- Fatigue associated w/ muscular weakness (including cardiac)
- Constipation d/t impaired muscle tone of the GI tract
- Characteristic ECG changes
- increased PR interval
- increased p wave
- flat or inverted T wave
- QT prolongation
- U wave
- ST depression
- Hyporeflexia
Symptoms of Severe Hypokalemia (< 2.5 mmol/L)
- Flaccid paralysis (can’t contract)
- Respiratory failure
- Cardiac arrhythmias/ arrest (tachyarrhythmias)