ABCs of EKG and Lab Values Flashcards
What is the order of the cardiac conduction system?
- Sinoatrail node (aka the pacemaker)
- Atrioventricular Node
- Atrioventricular Bundle (aka the Bundle of His)
- Bundle Branches
- Purkinje Fibers
An electrical pulse initiated in the sinoatrail node in the right atrium starts the conduction. Some of the impulse travels to the left atrium via the bachmann bundle. From the right atrium there is atrial depolarization (represented by the P wave) and then conduction travels to the atrioventricular node. From here it produces what is called an atrial kick (which is represented by the P-R segment). After the Atrial kick the conduction travels to the Bundle of His and then further to the bundle branches. It finally reaches the purkinje fibers where it creates ventricular contraction (represented by the QRS wave) and thus ultimately ending in repolarization (represented by the S-T segment).
What is an EKG?
An electrocardiogram records the summed electrical activity of the heart
The P wave in the cardiac cycle represents what?
Atrial depolarization
The QRS complex in the cardiac cycle represents what?
Ventricular depolarization
The S-T segment in the cardiac cycle represents what?
Ventricular repolarization
The SA node generating impulse and the atrial excitation beginning is represented by what part of the cardiac cycle?
Beginning of the P wave
When the impulse is delayed at the AV node what part of the cardiac cycle is this at?
The P wave
When the impulse passes to the hearts apex and the ventricular excitation begins what part of the cardiac cycle is this at?
The P-R segmanet
When the ventricular excitation is complete this is represented by what part of the cardiac cycle?
The QRS complex
What is the P wave responsible for?
depolarization of atrial myocardium
What is the QRS complex responsible for?
depolarization of ventricular myocardium
What is the T wave responsible for?
repolarization of the ventricular myocardium
When determining rhythm of the ventricles what do you look at?
R-R intervals
When determining rhythm of the atria what do you look at?
P-P intervals
What is an example of something that is regularly irregular?
- pattern such as increasing R-R durations
- Regular skipped beats
How would you determine rate if you could only count big box lines?
Find an R wave that was on a big box line, find the next big box and label that 300, count down 150, 100, 75, 60, 50, until you run into your next R wave
If you are between numbers state that (ex: rate 60 to 50)
What is a normal sinus rhythm?
60 bpm
What is sinus bradycardia?
sinus rhythm that is less than 60 bpm
What is sinus tachycardia?
sinus rhythm greater than 100 bpm
What is atrial fibrillation (a-fib)?
- an issue with the P wave (because the P wave does atrial depolarization)
- caused by continuous rapid firing of multiple atrial foci
- no single impulses depolarize the atria completely
- only occasional
What are characteristics of atrial fibrillation (a-fib)?
- No definite P wave
- Irregular rhythm
- Continuous chaotic atrial spikes (think about when you fib… this looks like a shakey voice)
- Irregular ventricular rhythm (QRS and T)
- Normal QRS complex
What are common causes of atrial fibrillation (a-fib)?
- MI: myocardial infarction
- CABG surgery: coronary artery bipass graft
- Valvular disease (mitral valve stenosis or regurg)
- CHF: congestive heart failure
- HTN: hypertension
- Chronic alcoholism
What are characteristics of premature ventricular contractions (PVC)?
- Early QRS complex
- Wider/bizarre QRS complex
- No P wave
- Deflection of the ST segment and T wave is opposite of theQRS
- Compensatory pause
- greater than or equal to 3 PVCs in a row = ventricular tachycardia
What are characteristics of Ventricular Tachycardia?
- Continuous runs of PVCs
- 150-250 bpm
- Each QRS is wide
What are common causes of ventricular tachycardia?
- Acute MI or ischemia
- Electrolyte imbalance
- Mediation toxicity
- Idiopathic
- Illicit drugs
What are clinical signs and symptoms of ventricular tachycardia?
- Hypotension (low BP)
- Syncope
- May deteriorate into ventricular fibrillation (cardiac arrest)
What is a part of an electrolyte panel?
Na+, K+, Cl-, CO2, pH
What is a part of a metabolic panel?
Na+, K+, Cl-, CO2, glucose, BUN, creatinine
What is tested when looking for kidney function?
BUN, creatinine, creatinine clearance, glucose, Ca2+, CO2
What is tested when looking for liver function?
Total bilirubin, alkaline phosphatase, aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), lactate dehydrogenase (LDT), prothrombin (PT), total protein, albumin
What are cardiac markers (MI/CHF)?
Cardiac troponins, creatine kinase (CK), beta-type natriuretic peptide (BNP), C-reactive protein (CRP), homocysteines
What is a part of a lipid panel?
Cholesterol, HDL, LDL, VLDL, triglycerides
What is a part of a complete blood count (CBC)?
Hgb, Hct, platelet count, WBC, PT, PTT, INR
What is the reference value for white blood cells?
5.0 - 10.0 x 10^9/L
If white blood cells are trending up what does that look like value wise? (leukocytosis)
> 11.0 x 10^9/L
What are causes of increased white blood cells? (leukocytosis)
Infection, Leukemia, Obesity, Inflammation, Stress/ Pain
What does an increase in white blood cells look like clinically? (leukocytosis)
Weakness, Fatigue, Fever, Dizziness, etc
With white blood cell increase consider timing therapy around _____ morning low level and _____ afternoon high peak
early, later
If white blood cells are trending down what does this look like value wise? (leukopenia and neutropenia)
< 4.0 x 10^9/L
What is excessive white blood cells called?
Leukocytosis
What is a lack of white blood cells called?
Leukopenia and Neutropenia
What are the causes of decreased white blood cells? (leukopenia and neutropenia)
Viral or bacterial infection, radiation, autoimmune disease
What kind of approach do you need to take with people with decreased white blood cells? (leukopenia and neutropenia)
Symptom based approach to determine appropriateness for activity; use RPE (Ex: presence of fever: may be appropriate to hold PT and OT)
What is the reference range for platelets?
150 - 400 x k/ul
What is the reference range for platelets that are trending down?
< 150 k/ul
What can happen when platelets trend down?
excessive bleeding
What are the potential causes of trending down platelets?
Infection, Leukemia, Radiation/ Chemo, Liver Disease
What is the clinical presentation of trending down platelets?
Brusing, Petechiae, Fatigue, Jaundice
What is the reference range for platelets that are trending up? (thrombocytosis)
> 450 k/ul
What is in called when platelets are above 450 k/ul?
Thrombocytosis
What are potential causes of trending up platelets? (thrombocytosis)
Inflammation, Cancer, Stress, Infection
What are clinical presentations of trending up platelets? (thrombocytosis)
Weakness, headache, dizziness, chest pain
What are therapy implications for platelets?
- < 10,000 and/or temperature that is > 100.5 degrees, hold therapy
- Symptoms based approach when determining appropriateness for activity
- Is pt a fall risk? If yes, increased risk of spontaneous hemorrhage
- Collaborate with interprofessional team: was there a transfusion prior to mobilization?
What are the hemoglobin (Hgb) ranges for males, females, and pregnant females?
- Male: 14-18 g/dL
- Female: 12-16 g/dL
- Pregnant Female: >11 g/dL
What are critical vales for hemoglobin (Hgb)?
< 5 g/dL or > 20 g/dL
If hemoglobin is trending up what are the causes and what is the presentation?
- Causes: CHF, dehydration, COPD, severe burns
- Presentation: Dizziness, arrhythmias, TIA symptoms, chest pain
If hemoglobin is trending down what are the causes and what is the presentation?
- Causes: Anemia, blood loss, lupus, kidney disease, stress to bone marrow
- Presentation: decreased endurance, pallor, tachycardia
What are therapy implications for changes in hemoglobin?
- Facility dependent: generally 8 g/dL will allow essential ADLs only, hold out of bed activity
- But there are pt’s with chronically low Hgb so you can take a symptoms based approach
What does a hematocrit value help tell you about?
Assess blood loss and fluid balance
What are the reference ranges for hematocrit (Hct) for males, females, and pregnant females?
- Males: 42-52%
- Females: 37-47%
- Pregnant Females: >33%
What are critical lab values for hematocrit?
< 15% or > 60%
What are the causes and clinical presentations of trending up hematocrit?
- Causes: COPD, burns, CHF, dehydration
- Clinical Presentation: fever, HA, dizziness, weakness, fatigue
What are the causes and clinical presentations of trending down hematocrit?
- Causes: leukemia, multiple myeloma, pregnancy, cirrhosis, RA
- Clinical Presentation: Pale skin, HA, dizziness (orthostatic hypotension), chest pain, arrhythmia, dyspnea
- monitor SpO2
What are therapy implications for fluctuating hematocrit?
- < 25%: essential ADLs only; hold out of bed activity
- symptoms- based approach with interprofessional collaboration
What is prothrombin time?
Measures time it takes plasma to clot when exposed to clotting factors in extrinsic pathways
What is prothrombin time (PT) used for?
Used to determine if Coumadin (warfarin) (blood thinner) therapy is effective
What is a normal prothrombin time (PT)?
11 - 12.5 seconds
If prothrombin time is >20 seconds the patient is at risk for what?
High risk for bleeding into the tissue - USE CAUTION
If a patients prothrombin time is trending up what therapy implications should you take?
- Fall prevention screening/ interventions
- Apply prolonged pressure to site if bleeding occurs
- Monitor for changes in neurological condition due to increased risk of intracranial bleeding
- Examine skin for bruising, petechiae, blood in urine
What is partial thromboplastin time (PTT)?
Measures time it takes plasma to clot when exposed to clotting factors in intrinsic pathways
What is partial thromboplastin time used for?
Used to determine if heparin (blood thinner) therapy is effective
What is a normal partial thromboplastin time?
30 - 40 seconds
What should you be watching for when partial thromboplastin time is trending up?
- increased risk for bleeding
- same precautions seen in prothrombin time
What is international normalized ratio (INR)?
Measure of how long it takes the blood to clot when an oral anticoagulant is used
What is a normal international normalized ration (INR)?
0.8 - 1.1
If INR is above the range what is there an increased risk for?
Bleeding
If INR is below the range what is there an increased risk for?
Clotting
If someone is on an anticoagulant they will have a _____ INR.
Higher
What falls under the definition of “sex”?
- Anatomy
- Physiology
- Genetics
- Hormones
What falls under the definition of “gender”?
- Identity
- Roles and Norms
- Relations
- Power
Most lab references are reported as _____ _____
Sex specific
What is the current recommendation by endocrinologist for transgender patients receiving gender-affirming hormone therapy?
Interpret based on the affirmed gender (except for high-sensitivity cardiac troponin and PSA)