Data Assessment Flashcards
1
Q
Your patient presents with:
PO2 72
PCO2 44
O2 sat 87%
Is this normal, ventilatory failure, or hypoxia?
A
Hypoxia
2
Q
Your patient presents with:
PO2 67
PCO2 59
O2 sat 88%
Is this normal, ventilatory failure, or hypoxia?
A
Ventilatory failure
3
Q
Your patient presents with:
PO2 57
PCO2 43
O2 sat 83%
Is this normal, ventilatory failure, or hypoxia?
A
Hypoxia
4
Q
Your patient presents with:
PO2 89
PCO2 40
O2 sat 95%
Is this normal, ventilatory failure, or hypoxia?
A
Normal ABG
5
Q
What is occurring in Phase I?
A
Inspiration
- ETCO2 = 0 (baseline)
6
Q
What is occurring in phase II?
A
- Start of expiration & starting to clear dead space
7
Q
What is occurring in phase III?
A
- Alveolar gas is exchanged
8
Q
What is occurring in phase IV?
A
Start of inhalation
9
Q
What part of the graph is showing up on our monitors?
A
- D = max ETCO2 = maximum sample of alveolar gas
10
Q
If C - D is not flat what does that tell the practitioner ?
A
- V/Q mismatch
- C-D is alveolar gas exchange & is flat in a healthy patient
11
Q
Alpha angle is normally 100-110 degrees what disease process would cause a widened angle?
A
- Disease process with a hard time pushing out CO2 = COPD, asthma
12
Q
Beta angle is normally 90 degrees, what disease process would cause a widen angle?
A
- Rebreathing = mixture of O2 & CO2
13
Q
What does this waveform represent?
A
Normal spontaneously breathing patient
14
Q
What does this waveform represent?
A
Normal ventilated patient
15
Q
What does this waveform represent?
A
- Rebreathing
- Soda Lyme needing changed
- Insufflation
- Inspiratory & expiratory valve failure
16
Q
What does this waveform represent?
A
- Curare Cleft
- Diaphragm movement
- check twitches
- if no twitches — see what the surgeon is doing
17
Q
What does this waveform represent?
A
- Esophageal intubation
- Obstructed sampling line
- How do you tell the difference? - blow into the sampling line
18
Q
What does this waveform represent?
A
- Cardiogenic oscillations
- Paralyzed patient coming back = rhythmic increase & decrease of intrathoracic pressure
19
Q
What does this waveform represent?
A
- Return of spontaneous respirations - asychronized with the vent
20
Q
What does this waveform represent?
A
- Shark fin = loss of alpha angle = hallmark sign
- Prolonged expiration
- COPD
- Bronchospasm
- Partial mucous plug
- Upper airway obstruction (FBO)
21
Q
What does this waveform represent?
A
- Cuff leak
- Over or under sampling
- Hyperventilation
- Increase dead space = V/Q mismatch
= look at ETCO2 & PCO2 to determine if this is the case
22
Q
What does this waveform represent?
A
- Leak in sampling line
- ET diluted - the positive pressure from the vent pushes more CO2 into the line
23
Q
What do these waveforms represent?
A
- Both could be faulty inspiratory flutter valve
24
Q
What does this trend capnogram represent?
A
- Acute event
- Disconnect from the machine = extubation, circuit popped off
- Total obstruction
- Mucous plug
- Sampling line
25
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
26
What does this trend capnogram represent ?
- Fixed a kink
- Small embolism with recovery
- Small bronchospasm with recovery
27
What does this trend capnogram represent ?
- Hypoventilation
- Hyperthermia (anything that increases metabolism)
- Tourniquet release
- CO2 insufflation
28
What are the normal parameters for pH, HCO3, & PCO2?
- pH 7.35 - 7.45
- HCO3 22 - 27
- pCO2 35 - 45
29
What is this ABG a sign of:
pH = 7.48
HCO3 = 38
PaCO2 = 53
- Metabolic alkalosis, partially compensated
30
What is this ABG a sign of:
pH = 7.37
HCO3 = 36
PaCO2 = 65
- Respiratory acidosis, compensated
31
What is this ABG a sign of:
pH = 7.32
HCO3 = 32
PaCO2 = 65
- Respiratory acidosis, partially compensated
32
What is this ABG a sign of:
pH = 7.69
HCO3 = 35
PaCO2 = 50
- Metabolic alkalosis, partially compensated
33
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)
34
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
35
What is a normal base excess/ deficit?
-2 to +2
36
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
37
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
38
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
39
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
40
How do you calculate the Anion gap?
AG (w/o K+) = [Na+] - ([Cl-] + [HCO3-])
AG (w/ K+) = ([Na+] + [K+]) - ([Cl-] + [HCO3-])
41
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)
42
Anion gap > 30 mmol/L is usually caused by ?
- Organic acidosis
- KULT acronym
- Keto acidosis
- Uremia
- Lactic acidosis
- Toxins: ethanol, aspirin, Toluene (solvent)
43
Anion gap < 20 mmol/L indicates what:?
- Rarely indicates a significant acidosis & is most often 2nd to changes in:
- Protein
- Phosphates
- Or change equivalents
44
What are the 2 electrolytes important in cell function?
- Calcium & Potassium
45
What does Potassium do for cell function?
- Maintain resting membrane potential
46
What does Calcium do for cell function?
- Maintain threshold potential
47
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
48
Where is majority of K+ excreted GI or renal?
- Major route = excretion in urine
| - Minor route = excreted via the GI
49
Renal regulation of K+ depends on what hormone?
- Aldosterone
- Rising concentration of K+ stimulates aldosterone synthesis & release
= Reduces K+ by increasing renal excretion
50
What is the most common cause of Hypokalemia (< 3.5)**
- Diuretic therapy:
| Thiazides & Loop diuretics
51
What are 9 other causes of Hypokalemia (< 3.5) other than diuretics?
1. Severe/chronic diarrhea/vomiting
2. Metabolic alkalosis (K+ moves into the cell)
3. Conn’s syndrome (increased aldosterone)
4. Tx of DKA (d/t increased loss of K+ in urine)
5. Inadequate K+ intake
6. Laxative abuse
7. Licorice abuse (increases aldosterone levels)
8. Beta blocker (K+ moves into cell)
9. Insulin overdose (K+ moves into cell)
52
Symptoms of Mild Hypokalemia (> 3.0)
- Usually asymptomatic
53
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
54
Symptoms of Severe Hypokalemia (< 2.5 mmol/L)
- Flaccid paralysis (can’t contract)
- Respiratory failure
- Cardiac arrhythmias/ arrest (tachyarrhythmias)
55
What is the most common cause of Hyperkalemia (> 5.0)? **
- Chronic kidney disease (reduced urinary excretion of K+)
56
What are other causes for hyperkalemia (> 5.0mmol/L) besides CKD?
1. Metabolic acidosis/ DKA (movement of K+ out of cell)
2. Severe tissue damage: rhabdomyolysis, trauma, major surgery (K+ leak out of damaged cell)
3. Cytotoxic drug therapy for hematological malignancy
4. Addison’s disease (reduced aldosterone)
5. Excessive K+ replacement therapy
6. Some drugs:
- ACEi,
- Spironolactone
57
Symptoms of Hyperkalemia
May be absent or relatively non-specific
- Muscle weakness/ fatigue
- Diarrhea/abdominal pain
- Cardiac palpitations
- Characteristic ECG changes:
- Peaked T wave
- Flat P wave
- PR prolongation
- prolonged P wave
- Widened QRS & morphology changes
58
At what K+ level does the risk of potentially fatal ventricular arrhythmias & cardiac arrest present ?
- As K+ rises above 6.5 mmol/L
| - present as slow arrhythmias: sinus brady, AV blocks, Junctional/escape beats
59
What is the most dominant cation in the extracellular fluid?
- Sodium, major contributor of the osmolality of the extracellular fluid
60
What is the main function of Na+
- Regulating water balance & maintaining BP
61
How are normal limits of Na+ controlled?
1. Thirst response
2. Normal renal & GI function
3. Appropriate release of AVP (vasopressin)
4. Appropriate release of aldosterone
5. Intact renin-angiotensin pathway
“Think Brain”
62
9 Causes of Hyponatremia (< 135)
1. Heart failure
2. Cirrhosis
3. Hyperglycemia - DKA
4. Acute & chronic kidney disease
5. Syndrome of inappropriate antidiuretic hormone (ADH)
6. Chronic vomiting/diarrhea
7. Addison’s disease (adrenal insufficiency)
8. Diuretic therapy
9. Fluid replacement therapy
63
What are symptoms of mild hyponatremia (130- 135 mmol/L)
- Usually asymptomatic
64
What are symptoms of moderate hyponatremia (125- 130 mmol/L)?
- Anorexia
- Nausea/vomiting
- Abdominal cramps
65
What are symptoms of severe hyponatremia (< 125 mmol/L)?
- All other symptoms of moderate plus:
- Agitation
- Confusion
- Hallucinations
66
What are symptoms of the most severe hyponatremia (< 115 mmol/L)?
- Seizures
- Coma
- Death
67
What are 8 causes of hypernatremia ( > 145mmol/L)?
1. CKD
2. Inadequate water intake (common in elderly)
3. Failure of the thrust response d/t unconsciousness/head injury
4. Conn’s disease (primary aldosteronism)
5. Cushing’s disease
6. Diabetes insipidus
7. Over-vigorous Na replacement therapy
8 Lithium therapy
68
What are symptoms of mild hypernatremia (145 - 150 mmol/L)?
- Usually asymptomatic
69
What are symptoms of moderate hypernatremia (150 - 159 mmol/L)?
- Anorexia
- Muscle weakness
- Nausea vomiting
“Think GI”
70
What are symptoms of severe hypernatremia ( > 160)?
Due to dehydration of brain cells:
- Lethargy
- Irritability
- Altered LOC
- Coma
- Acute onset of severe hypernatremia is potentially fatal
71
What is the normal range for Chloride?
98 - 107 mEq/L
72
Why is Chloride important?
- Determines water movement between extracellular & intracellular compartments =
- regulation of blood volume & blood pressure
- Maintains the electrochemical neutrality of plasma (70% of anions in the AG, HCO3 30%)
- Essential in the digestion/absorption of food & control of GI bacterial growth
- Essential for the effective transport of CO2 from tissue to lungs & the maintenance of normal blood pH
73
Causes of hypochloremia & hyperchloremia
- Cl- closely parallels Na+ in both health & disease, the causes of hypochloremia are identical to hyponatremia
- Anorexia, N/V, ABD cramps
- Agitation, Confusion, Hallucinations
- Seizures, Coma, Death
- Hyperchloremia = Hypernatremia
- Anorexia, N/V, muscle weakness
- Lethargy
- Irritability
- Altered LOC
- Coma
74
Ionized calcium normal range?
- 4.6 - 5.3 mg/dL
| FYI: 1.3 - 2.1 mEq/L
75
Importance of iCa+
- Bone mineralization
- Cellular processes
- Contractility of the heart & skeletal muscle
- Neuromuscular transmission
- Hormone secretion enzymatic reactions: blood coagulation
76
When do you see hypocalcemia?
- Never a singular finding
| - May occur in the context of co-existing acidosis, hypothermia & dilution
77
What are 6 causes of hypocalcemia ?
1. Hypothyroidism (reduced PTH d/t disease/damage of the parathyroid)
2. Vit D deficiency (reduced production, diet deficiency, or malabsorption)
3. CKD
4. Chronic Liver disease
5. Critical illness:
- Sepsis
- AKI
- Acute pancreatitis
- Rhabdomyolysis
- Severe burns
- Massive red blood cell transfusion
6. Major surgery = saggy BP — need amp of Ca
78
What are symptoms of moderate hypocalcemia?
Related neural signaling/neuromuscular transmission
- Muscle twitching
- Carpopedal spasm = + Trousseau’s sign
- Paresthesia (tingling & numbness)
79
What are symptoms of severe hypocalcemia?
- Tetany with laryngeal spasm & breathing difficulty
- Convulsions, seizures/fits
- Cardiac arrhythmia with characteristic ECG changes:
- QT prolongation (secondary to lengthened ST segment)
- Rare but can lead to Torsades, VT or complete heart block
80
What are the 3 most common causes of hypercalcemia? *
1. Primary hyperparathyroidism (excessive uncontrolled secretion of PTH)
2. Malignant disease: especially lung, breast, & esophagus cancer
3. Drugs: thiazide diuretics, lithium, excessive antacids & Vit. D
81
What are 4 rare causes of hypercalcemia ?
1. Tuberculosis
2. Sarcoidosis
3. Hyperthyroidism
4. Inherited hypercalcemia
82
What are the symptoms of Moderate hypercalcemia?
(Mild = asymptomatic)
- Abdominal pain
- Nausea
- Muscle weakness
- Constipation
- Thirst & polyuria
- Tiredness, fatigue, depression
- Palpitations/ ECG changes:
- Short QT interval
- Renal (calcium) stones
83
What are the symptoms of severe hypercalcemia?
- Convulsions
| - Coma
84
What is a cause for chronic/long standing hypercalcemia?
- Irreversible chronic kidney disease
85
What is the importance of a lactate level?
- increase in lactate levels are an early sensitive indicator of imbalance between tissue oxygen demand & supply
- marker of tissue hypoperfusion in patients with circulatory shock
- Prognostic indicator for patient outcome
- An index of adequacy of resuscitation after shock
- A marker for monitoring resuscitation therapies
86
What is a normal lactate range ?
9 - 14 mg/dL (unstressed)
| - Can go as high as 18 if stressed
87
Lactic acidosis is the most common cause of ?
- Metabolic acidosis
| - Characterized by persistent hyperlactatemia (usually > 45 mg/dL) in association with reduced blood pH (< 7.35)
88
The development of lactic acidosis depends on :
1. The magnitude of hyperlactatemia
2. The buffering capacity of the body
3. The co-existence of other conditions that produce tachypnea & alkalosis (liver disease, sepsis)
89
7 causes of Type A Lactic Acidosis
“Hypoxia” = inadequate tissue oxygenations
1. Shock from blood loss/sepsis
2. Myocardial infarction/ cardiac arrest
3. Congestive heart failure
4. Pulmonary edema
5. Severe anemia
6. Severe hypoxemia
7. Carbon monoxide poisoning
90
What are 9 causes of Type B Lactic acidosis
“Metabolic”
1. Liver disease
2. Kidney disease
3. DKA
4. Leukemia
5. HIV
6. Sepsis & meningitis
7. Congenital lactic acidosis: forms of muscular dystrophy
8. Drugs & toxins
9. Strenuous exercise
91
13 Drugs that are associated with Type B Lactic acidosis
1. Biguanides (Metformin)
2. Ethanol
3. Methanol
4. Antiretroviral drugs
5. Cyanide
6. Theophylline
7. Cocaine
8. Simvastatin
9. Salicylates
10. Paracetamol (acetaminophen)
11. Lactulose
12. Propylene glycol
13. Epinephrine & norepinephrine
92
What is a normal Creatinine level?
- Men: 0.6 -1
(Women usually run a little lower but do not need to know those values for the exam)
- the value is a used to assess kidney dysfunction - the marker is based on the constancy of endogenous creatinine production & the observation that creatinine is cleared from the blood to urine almost entirely by glomerular filtration
93
What reflects the rate at which blood is filtered in the kidneys?
- Glomerular filtration rate (GFR)
| - Kidney disease/dysfunction is associated with reduction in GFR
94
11 Causes of high Creatinine
1. Acute tubular necrosis
2. Dehydration
3. Diabetic nephropathy
4. Glomerulonephritis
5. Kidney failure
6. Muscular dystrophy (beginning stages)
7. Preeclampsia
8. Pyelonephritis
9. Reduced kidney blood flow (shock, congestive heart failure)
10. Rhabdomyolysis
11. Urinary- tract obstruction
95
2 causes for low creatinine
1. Muscular dystrophy (late stage)
| 2. Myasthenia gravis
96
What is the principle distinction between CKD & AKI?
- The speed of progression “the decline in GFR”
- AKI: rapid progression over a period of hrs & days
- potentially reversible
- CKD: slow progression over a period of months, years, & even decades
- irreversible
- Medical intervention can slow progression
97
When is kidney replacement therapy required?
(Either dialysis or transplantation)
| - Required for survival when creatinine exceeds 6.8 mg/dL & may be as high as 11.3 mg/dL (6-10 x’s baseline)
98
What GFR is abnormal at any age?
- Less than 75 mL/min/1.73m2
| - GFR decreases as we age and that is normal but 70+ yo should remain at a GFR of 75 mL/min
99
Cardiac troponin markers
- Normally only barely detectable or undetectable in blood
- are sensitive & specific blood markers of Myocardial NECROSIS
- An aid in the diagnosis of MI & in the risk stratification of patient with acute coronary syndromes (ACS) w/ respect to their relative risk of mortality
100
Criteria to satisfy a diagnosis of acute, evolving or recent MI?
- Must rise above the 99th percentile
& at least one of the following:
- Symptoms of c Adrian ischemia
- ECG changes consistent w/ new ischemia
- Imaging evidence of new loss of viable myocardium
- Identification of an intracoronary thrombus by angiography or at autopsy
101
How should troponins be measured?
- First detectable 4- 8 hrs after the onset of chest pain
- Peak 12- 48 hrs -
- Plasma cTNI & CTnT levels remain elevated several days after a severe MI
- Serial meausurements are necessary
- at presentation
- & again 3- 6 hrs later
- 6-12 hr to definitively exclude a diagnosis of MI if clinical doubt remains
102
How can you exclude an MI with troponins?
- A diagnosis of MI can usually be excluded if troponin remains negative over a period of 6-12 hrs after onset of symptoms
- MI is also excluded if an abnormal results remains unchanged (< 20%) during the hours after onset of symptoms
103
Should you delay reperfusion treatment for troponin test results?
- Presentation w/ typical ischemic chest pain & ST-segment elevation is a diagnosis of MI
- Reperfusion tx of this patient should not be delayed by troponin testing
104
When does a troponin have the greatest diagnostic value?
- In the absence of unequivocal ECG evidence of MI = NSTEMI
105
12 Causes other than MI that can increase troponin levels
1. Heart failure
2. Tachyarrhythmia
3. Cardiomyopathy
4. Myocarditis pericarditis
5. Renal failure (ESRD)
6. Blunt chest trauma
7. Pulmonary embolism
8. Sepsis/septic shock
9. Aortic valve disease
10. Cerebrovascular accident (stroke)
11. Cardiotoxic drugs
12. Extreme exertion (marathon running)
106
What are natriuretic peptides (BNP - NT-proBNP)
- Derived from heart muscle cells & are present in blood at very low concentrations in healthy individuals
- Increased concentrations are associated with many cardiac & some non-cardiac diseases
107
Why do we use BNP or NT-proBNP?
- Aids in the diagnosis of heart failure
- Both test have equal diagnostic value
- The physiological trigger for synthesis of proBNP within cardiac myocytes & release of BNP & NT-proBNP to the circulation is cardiac-wall stress
- induced by increased pressure/volume
- “Grades Heart failure”
108
What are 4 BNP effects in the body?
1. Multiplicity hormonal effects that contribute to cardiovascular hemostasis, including regulation of blood volume & blood pressure
2. BNP promotes increased Na & water loss in urine (natriuresis & diuresis) & induces vasodilation*
(May or may not be good since pt is in heart failure) trying to off load stress/ fluid from the heart
3. Inhibitory effect on the renin-aldosterone axis
4. Protects the heart from fibrosis & hypertrophy
109
What is the half life of BNP?
- 20 minutes
| - Eliminated via renal & non-renal routes
110
What is the range for BNP?
- For the exam know that BNP increases with age and women have higher levels
- (Ex: male 65-74 yr. Avg BNP 23 (w/ a range of 7-58) - Female 65-74 yr. Avg BNP 37 (w/ a range of 19- 111)
- Acute heart failure rule out = < 100 BNP
- Acute heart failure rule in = > 500 BNP (age is not a factor)
- if between 100- 500 — get an ECHO for diagnosis (gold standard)
111
What is the heart failure grading score based on the NYHA class and Mean BNP?
- Class I = asymptomatic = BNP 244, (+/- 286)
- Class II = mild = BNP 389 (+/- 374)
- Class III = moderate = BNP 640 (+/- 447)
- Class IV = severe = BNP 817 (+/- 435)
112
What is does an increased D-dimer relate to?
- An increased blood concentration of D-dimer provides evidence of ON-GOING fibrinolysis = fibrin clot formation
- normally undetectable or only at low levels unless your body is forming & breaking down significant blood clots
- Used for thrombotic conditions:
- Deep vein thrombosis
- Pulmonary embolism
113
What are D-dimers?
- Fibrin (ogen) degradation product (small protein fragment present in the blood) that provides a marker of ongoing fibrinolysis (blood clot degraded by fibrinolysis) & thereby coagulation activation
114
What are 12 causes of an increased D-dimer other than VTE?
1. Arterial thrombotic diseases: MI, a-fib, CVA, limb ischemia
2. DIC
3. Sickle cell crisis
4. Aortic dissecting aneurysm
5. HF
6. Severe infection/sepsis/SIRS; severe inflammation
7. Surgery/trauma
8. Cancer
9. Cirrhosis
10. AKI/ESRD
11. Normal pregnancy & preeclampsia & eclampsia
12. Use of Thrombolytic drugs
115
What is the sensitivity and specificity for VTE with a D-dimer?
- High sensitivity for VTE (90-98%)
- But limited by its low specificity for VTE (<50%)
- Negative test result rules out the likelihood of the disease
- But a positive test does not tell the practitioner “specifically” if the patient has a VTE (may be a PE, DIC, sepsis, cancer etc)
116
What is the gold standard for diagnosis of DVT? PE?
- DVT: Ultrasound scan of the legs
- PE: Chest CT
- The D-dimer is used to tell the practitioner if theses expensive test need to be ran
- If the D-dimer is low = pre-test = Wells score - VTE can be ruled out
117
What is the current universal reference for D-dimer assays?
- Assays vary greatly & there is no universal standard/ reference interval or diagnostic cut-off value for exclusion of VTE
118
What is the Wells Score used for?
Point system to determine the clinical probability of DVT or PE
- if the patient presents with low probability = get a D-dimer
- if low DVT/PE is ruled out;
- if high get imaging
- if the patient presents with high probability = get imaging
119
Wells Score for DVT?
2 or more = high probability
1 or less = low probability
+ 1 point for :
- Active cancer
- Paralysis or recent cast immobilization
- Bed rest > 3 days or surgery < 4 weeks ago
- Pain on palpation of deep veins
- Swelling of entire leg
- Calf swelling > 3 cm difference in affected limb
- Pitting edema in affected limb
- Dilated superficial veins in affected limb
- Previously documented DVT
- Alternative diagnosis at least as likely as DVT = -2
120
Wells Score for PE?
More than 4 points = high probability
4 or less = low probability
```
+ 1.5
- Previous PE or DVT
- Heart rate > 100 bpm
- Recent surgery or immobilization
+ 3
- Clinical signs of DVT (leg swelling pain)
- Alternative diagnosis less likely than PE
+1
- Hemoptysis
- Cancer
```
121
What is a CRP
- C-reactive protein
- a non-specific blood marker of organic disease from increased production of large protein polypeptide chains that are synthesized in hepatocytes
122
What is a normal CRP? And what increases a CRP level?
- Normal = < 5.0 mg/L
| - Increased (> 10) = innate immune response to infection & major tissue injury/ insult
123
6 Causes associated with increased CRP
“Immune problems”
1. Bacterial/ Viral/ Fungal infection; sepsis
(Bacteria = higher rise than viral)
2. Arthritis
3. Inflammatory autoimmune: arthritis, vasculitis
4. Autoimmune: Crohn’s, SLE, sclerosis, UC, Polymyalgia rheumatica
5. Disease process: MI, acute pancreatitis, cancer
6. Injury: trauma, burns, fractures, surgery
124
What is an ESR?
“Sed rate”
- Measures how quickly erythrocytes settle at the bottom of a test tube that contains an anti coagulated blood sample after 1 hour (minimum)
- Normally RBC settle relatively slowly
125
What does a faster than normal ESR mean?
- Inflammation in the body:
- arthritis, vasculitis or inflammatory bowel disease
- Chronic condition or immune disorder
- monitor SLE or RA
- Infection or injury
126
What may cause a slow ESR?
- Sickle cell disease
- CHF
- Kidney disease
127
What are the Erythrocyte sedimentation rates (ESR) by age group?
Adults (< 50 yrs)
- Men < 15 mm/hr
- Women < 20 mm/hr
Adults (> 50yrs)
- Men >/= 20 mm/hr
- Women >/= 30 mm/hr
> 100 = active disease but not what disease
128
What are 4 importance of liver function tests?
1. Screen for liver infections: hepatitis
2. Monitor progression of disease & how well tx is working
- viral or alcoholic hepatitis
3. Measure the severity of a disease
- particularly scarring of the liver = cirrhosis
4. Monitor possible side effects of medications
= “screening + monitoring + grading”
129
Alanine transminase (ALT)
- Normal = 7 to 55 U/L
- A liver enzyme that helps convert proteins into energy for the liver cells
- Increased in liver damage
130
Aspartame transaminase (AST)
- Normal = 8 to 48 U/L
- A liver enzyme that helps metabolize amino acids
- Increased in liver damage, disease or muscle damage
131
Alkaline phosphatase (ALP)
- Normal = 40 to 129 U/L
- An enzyme (in liver & bone) that breaks down proteins
- Increases in liver damage, disease or certain bone diseases
132
Albumin & total protein
- Albumin = 3.5 to 5.0 g/dL
- Total protein = 6.3 to 7.9 g/dL
- Liver proteins that help fight infections & perform other functions
- When the liver is damaged levels DECREASE
133
Bilirubin
- Normal = 0.1 to 1.2 mg/dL
- Produced during the normal breakdown of RBCs
- Bilirubin passes through the liver & is excreted in stool
- Elevated levels of bilirubin = liver damage or certain types of anemia
134
Gamma- glutamyltransferase (GGT)
- Normal = 8 to 61 U/L
- An enzyme in the blood
- Increased in liver or bile duct damage
135
Prothrombin time (PT)
- Normal = 9.4 to 12.5 seconds
- The time it takes your blood to clot
- Increased in liver damage or anticoagulation therapy
