Laboratory Studies Flashcards
Arterial Blood Gas
Blood taken from an artery.
Serum
The clear liquid separated from clotted blood.
Coagulation
The change of blood from liquid to solid.
POC
Point of care.
Cultures
The propagation of microorganisms or of living tissue cells in media conducive to their growth.
Critical Care Time
Care provided to any patient that is at serious risk for deterioration that may lead to permanent bodily harm or death.
What is CBC and what does it test/look for?
The CBC is the Complete Blood Count.
It looks for two main things:
- Infection
- Anemia
The CBC shows us the patient’s _______.
- White Blood Cell Count (WBC)
- Hgb Hemoglobin
- Hct Hematocrit
If the WBC is high ______.
A condition called leukocytosis, that is indicative of infection.
The H&H portion of the CBC looks for _____.
Anemia
H&H stands for hemoglobin and hematocrit – If these are low, it indicates anemia.
Anemia is a condition in which a patient lacks enough healthy red blood cells to carry adequate oxygen to the body’s organs and tissues. Having anemia can make a patient feel fatigued, weak, and even short of breath.
The CBC can also assess for disorders called _____.
Platelet disorders by looking at the platelet count. If a patient has thrombocytopenia, it means they don’t have enough platelets.
What about the BMP? What does this lab study look for?
- Electrolytes – Sodium (Na), Potassium (K), and Chlorine (Cl-)
- Kidney Function – BUN and Creatinine
- Blood Glucose Level – “Blood sugar”
Electrolytes play an important role in the body by ______.
Regulating nerve and muscle function, hydrating the body, balancing blood pH, and helping to rebuild damaged tissue.
When a patient is dehydrated, it can cause changes in the electrolytes.
If BUN or Creatinine is high, it can indicate _____.
Renal failure
Blood sugar testing is especially useful for the management of ______.
Diabetes
What is the CMP?
CMP is the Comprehensive Metabolic Panel – very similar to the BMP.
It still shows us the patient’s electrolytes, kidney function, and blood sugar, but will also provide providers with a look at the patient’s liver function.
In summary, the CMP includes everything the BMP included but also contains the Liver Function Tests (LFTs).
What are the 3 most important liver function tests?
- AST – Aspartate Transaminase
- ALT – Alanine Transaminase
- Alk Phos – Alkaline Phosphate
If they are elevated, it can indicate liver damage or even liver failure.
In addition to blood work, the provider can also order a urine sample. This lab is called _____.
Urinalysis
What is one of the primary reasons a provider orders a urinalysis?
To look for signs of a urinary tract infection (UTI).
What are the signs that can be seen in the urine?
Signs that can be in urine include:
- High white blood cell count (WBC).
- Red blood cells (RBCs)
- Bacteria
Having Red Blood Cells in the urine is called ______.
Hematuria
Conditions that can cause hematuria in a patient.
- UTIs
- UTIs can actually cause bloody urine, because bacteria disrupt the lining of the bladder, causing inflammation and bleeding.
- Kidney Stones (common)
- When a kidney stone moved from the bladder into the ureter, it scrapes the walls of the ureter, causing the patient severe pain and bloody urine.
- Trauma
- Cancer
- Polycystic
- Kidney diseases
- Blood clotting disorders
- Inflammation of the urinary system
What are the different imaging labs?
- X-rays
- CT scans (aka CAT scan)
- Ultrasounds
What is an X-ray imaging?
X-ray imaging can create images of the inside of your body. The images show the parts of your body in different shades of black white because different tissues absorb different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat and other soft tissues absorb less and look gray.
What is the most common use of X-rays?
The common use of x-rays is checking broken bones (fractures).
What are some other ways x-rays can be used?
Chest x-rays can spot lung infections (this is called pneumonia).
Mammograms use x-rays to look for breast cancer.
What is a CT scan/CAT scan?
A computer tomography (CT or CAT) scan also allows doctors to see inside your body. CT scans use a combination of 64 simultaneous X-rays, and a computer to create pictures of your organ, bones, and other tissues. It shows more detail than a regular X-ray.
What are the ≠ types of CT scans?
- CT without
- CT with IV Contrast aka Angiogram
- CT Abdomen/Pelvis with PO
CT Without
Abbreviated to CT w/o
Plain CT scans, where no contrast, or dye, is used.
Diagnoses that can be made using CT w/o include:
- Cerebrovascular accidents
- Lung infections like pneumonia
- Fractures
- Kidney stones
CT with IV Contrast aka Angiogram
Abbreviated to CTA or CT w/
With a CT angiogram, the patient is given contrast (or dye) through their IV. This means that the dye enters the bloodstream. The heart will pump the dyed blood throughout the body, so pretty much every blood vessel in the body will light up.
Diagnoses that can be made using a CT w/.
Used to evaluate blood vessels and can diagnose things like:
- Aortic aneurysm
- CVAs
- Problems with the carotid arteries
- Pulmonary embolisms
- Remember these are blood clots in the pulmonary arteries.
CT Abdomen/Pelvis with PO Contrast
Abbreviated to CT A/P w/ PO
PO is the abbreviation for Per Os, or by mouth, so with this CT scan, the patient drinks the contrast dye. Then their entire GI systems light up.
CT A/P w/ PO can be used to look for GI conditions like:
- Appendicitis
- Bowel blockages
- Diverticulitis.
What are the purpose and use of Ultrasounds?
Ultrasounds use high-frequency sound waves to generate real-time images. For any disease involving the reproductive organs, ultrasounds are preferred because they do not use radiation.
Diseases that can be diagnosed using Ultrasounds.
- Ovarian torsions
- Testicular torsions
- Ectopic pregnancies.
Ultrasounds are also used to assess _______.
Fluid and flow, so they can diagnose blood clots in the extremities.
- DVTs – Deep veins thrombosis
They are also excellent tools for looking at the gallbladder (a fluid-filled sac that sits in the right upper abdominal quadrant).
Ultrasounds can reveal gallbladder inflammation and gallbladder stones.
Rhythm
Coordination/pattern of the heart’s contractions.
NSR
Normal Sinus Rhythm; Normal rhythm & Rate 60-100 BPM.
SB
Sinus Bradycardia; Normal rhythm & rate < 60.
ST
Sinus Tachycardia; Normal rhythm & rate > 100.
A fib
Atrial Fibrillation
A flutter
Atrial Flutter
Paced
The pacemaker is functioning.
SVT
Supraventricular Tachycardia
Ectopy
Early (premature) or extra heartbeats.
PVC
Premature Ventricular Contraction
PAC
Premature Atrial Contraction
Axis
Electrical orientation of contractions.
LAD
Left Axis Deviation
RAD
Right Axis Deviation
LAFB
Left Anterior Fascicular Block
Intervals
Refers to the timing of contractions.
LBBB
Left Bundle Branch Block
RBBB
Right Bundle Branch Block
1º AVB
First Degree AV Block (2 and 3 degree).
Other intervals
- Prolonged PR
- Prolonged QT
QRS Complex
LVH – Left Ventricular Hypertrophy
PRWP – Poor R wave Progression
ST segments
ST segments can either be normal, depressed, or elevated. There can also be non-specific changes in the ST/T segments.
ST ↑
Acute ST elevation
ST ↓
Acute ST depression
NSST∆’s
Nonspecific ST/T changes
Reciprocal changes (ST elevation with reciprocal depression)
No acute ST/T changes
T-wave inversions or T-wave flattening
Comparison of EKGs
If possible, provider like to compare a patient’s EKG to a prior EKG, to see if anything abnormal is acute or chronic. Be sure to note the time and date of the old EKG.
- No old EKG available for comparison.
- No change when compared to an EKG dates ____.
- When compared to an EKG dated _____, the following changes are noted _____.
Inferior Leads
II, III, aVF
Lateral Leads
I, aVR, aVL, V5, V6
Anterior Leads
V3, V4
Septal Leads
V1, V2
Room Air (RA)
This means the patient is not on oxygen. They are breathing the air in the room, like everyone else.
Documentation:
Oxygen saturation of 99% RA
Nasal Cannula (NC)
A nasal cannula is a plastic tube that is placed into the patient’s nostrils. It typically delivers oxygen at 2 LPM (liters per minute), although it may be set anywhere from 1-6 LPM.
Documentation:
100% on 2L NC
Facial Mask (FM)
A plastic mask fit over the nose and mouth. Oxygen is typically set from 6-15 LPM.
Documentation:
100% on 10L FM
Non-Rebreather Mask (NRB)
This is very similar to a facial mask, however, the NRB has an attached reservoir bag, typically one liter, that connects to an external oxygen tank or bulk supply system. It delivers 10 to 15 LPM.
Documentation:
100% on 10L NRB
Critical Care Oxygen Route
Continuous Positive Airway Pressure (CPAP)
A large mask is trapped to the patient’s face, delivering continuous air pressure.
Critical Care Oxygen Route
Biphasic Positive Airways Pressure (BiPAP)
Similar to CPAP, a large mask is trapped to the patient’s face. With a BiPAP, however, the machine alternates pushing air in and letting it out.
Critical Care Oxygen Route
Bag Valve Mask (BVM)
A large facial mask held in place by hand and attached to an Ambu bag. The Ambu bag is used to manually inflate the patient’s lungs.
Critical Care Oxygen Route
Endotracheal Tube (ETT)
ETTs are placed by endotracheal intubation, an ET tube goes through the patient’s mouth and down the trachea. It is used if the pt is experiencing respiratory failure and is unable to breathe on their own. Patients are typically sedated and unconscious for this procedure. ET tubes are typically attached to an Ambu bag temporarily until they can be attached to a ventilator (breathing machine).
Pulse Ox Interpretation
It is important to document if the patient is on supplemental oxygen, and how much. Then ask your provider for their interpretation!
Example:
88% on 2L NC. Interpretation: Hypoxic.
X-Ray Interpretation
Unlike CT scans and Ultrasounds, which are usually interpreted by radiologists, X-rays can typically be interpreted by your physician. When documenting an x-ray interpretation, always record the number of views, as well as “Interpreted by the physician.” The interpretation must include the physician’s findings.
Example:
Three views of the left knee. These reveal moderate degenerative changes, worst in the medial compartment. There is also hardware in the right distal femur. No signs of acute fracture. Interpreted by the physician.
EKG Interpretations
An EKG interpretation must include rate, rhythm, and the physicians’ findings.
Example:
EKG shows normal sinus rhythm, with a rate of 75 bpm. No acute ST/T changes. No signs of ischemia.
Procedures
A good rule of thumb is that if your provider has done something to fix or improve the patient, it should be documented as a procedure. Common procedures include splint applications (for injured extremities), laceration repairs (stitches sutures), foreign body removals, and Incision & Drainage (I&D) for abscesses.
What are the Cardiac and Respiratory Labs?
- Trop – Troponin
- BNP – B-type Natriuretic Peptide
- ABG – Arterial Blood Gas
- VBG – Venous Blood Gas
What is the significance of a high Troponin level?
Heart damage
What is the significance of a high BNP (B-type Natriuretic Peptide) level?
Congestive Heart Failure
What are the abnormal level of ABG (Arterial Blood Gas) and their significance?
Low pH – Acidosis
High/Low HCO3 – Metabolic problem
High/Low pCO2 – Respiratory problems
Low pO2 – Hypoxia
What are the abnormal levels of VBG (Venous Blood Gas) and their significance?
Low pH – Acidosis
High pH – Alkalosis
The Cardiac Order Set is the following ______.
CBC
BMP
Troponin
EKG
CXR
* This set of orders will be placed for almost every adult patient complaining of chest pain.
Becoming familiar with this order set will allow you to become more efficient at anticipating and tracking results for chest pain patients.
What is the significance of a high D-Dimer?
Must rule out PE.
* If a D-Dimer is ordered, it means the physician is considering a pulmonary embolism as one of their differential diagnosis (DDx).
* D-Dimer is a protein that is excreted by clots of blood. The amount of D-Dimer circulating in the body can be measured with the lab test D-Dimer.
*If the D-Dimer is negative, a PE can be excluded from the DDx
*If the D-Dimer is positive, it does not necessarily mean there is a PE. It only means the patient must be ruled out for a PE; they must receive a CTA Chest or VQ scan.
CSF Analysis
Cerebrospinal Fluid – Micro Analysis
* Typically four tubes of CSF are obtained during a lumbar puncture.
* Any abnormal results that are only seen in the first two tubes are likely contamination; if the value is abnormal in all four tubes then the results are valid.
What is the significance of a low level of CSF Gluc (Cerebrospinal Fluid Glucose)?
Possible bacterial meningitis.
What is the significance of a high CSF Prot (Cerebrospinal Fluid Protein)?
Possible Meningitis.
What is the significance of >3 in Tube 4 for CSF WBC (Cerebrospinal Fluid White Blood Cells)?
Possible Meningitis.
What is the significance of positive bacteria for CSF Gram Stain?
Likely Bacterial Meningitis.
What is the significance of >0 in Tube 4 for CSF RBC?
Subarachnoid Hemorrhage (brain bleed).
What is the significance of a high level of PT (Prothrombin Time)?
Blood is too thin.
What is the significance of a >3.0 (supratherapeutic) and <2.0 (subtherapeutic) of INR (International Normalized Ratio)?
> 3.0 (Supratherapeutic) – Too much Coumadin
< 2.0 (Subtherapeutic) – Not enough Coumadin
What is the significance of a high level of PTT (Partial Thromboplastin Time)?
Blood is too thin.
PT (Prothrombin Time) vs. INR (International Normalized Ratio) vs. PTT (Partial Thromboplastin Time)
* The PT and INR are actually the same test, just two different representations of the results. It is most often ordered as “PT/INR.”
* PT/INR/PTT basically tells us blood thickness, which we worry about in people with Hx of stroke, or hemorrhages (too thin, too thick).
* The INR is an adjusted PT value, accounting for differences between patients.
* It is normalized so the INR = 1.0 for every patient that is not on Coumadin.
What does a positive and negative level of HCG (Urine ßHCG)?
Positive – Pregnant
Negative – Not pregnant
What does a positive or a negative level of Serum HCG Qual (Serum ßHCG Qualitative)?
Positive – Pregnant
Negative – Not pregnant
What does a higher unchanged or lower level of Serum HCG Quant (Serum ßHCG Qualitative)?
Higher – Further along in pregnancy
Unchanged – Failed pregnancy
Lower – Ectopic pregnancy
What does an Rh Negative in the T+S/ABORh (Type and Screen/Blood Type) tell us?
Rh Negative – Need RhoGAM shot if pregnant
T+X (Type and Cross)
Gets blood ready for transfusion – Possible blood transfusion.
What is the purpose of ordering a Urinalysis?
To look for signs of a urinary tract infection (UTI).
What are the signs that can be seen in the urine?
Signs that can be seen in the urine include:
- High white blood cell (WBC)
- Red blood cells (RBCs)
- Bacteria
Microscopic Urinalysis
- Elevated White Blood Cells – UTI
- Elevated Red Blood Cells – UTI vs. Kidney Stone
- Bacteria – UTI
- Epithelial Cells – Contaminated Sample
Having red blood cells in the urine is called____.
Hematuria.
What is something to note about cultures (CX)?
Cultures will never result the same day they are ordered. Unlike any other lab, you will never document the results of a blood culture after it is ordered.
* Instead you will always write “______ cultures ordered, results pending.”
What is the significance/purpose behind ordering a BCx (Blood Culture)?
To look for germs (such as bacteria or fungi) in the blood.
– Sepsis
What is the significance/purpose behind ordering a UCx (Urine Culture)?
To find germs (such as bacteria) in the urine that can cause an infection.
– UTI
What is the significance/purpose of ordering a Wound or Stool Culture?
No need to know.
“Results pending”
What is the significance/purpose behind ordering a GC/CT Genital Culture?
Gonorrhea or Chlamydia (STD’s): ED will call patient if Cx is positive.
What is the significance of a large (abnormal level) finding in Ketones (Serum Ketones) lab?
Likely Diabetic Ketoacidosis (DKA)
What is the significance of a less than 80 mg or more than 110 mg in Accu-Check (Finger-Stick Blood Glucose (FSBG))?
Less than 80 mg – Low blood sugar
More than 110 mg – High blood sugar
Three Key Labs For Efficiency
D-Dim (D-Dimer)
Trop (Troponin)
Creat (Creatinine) – from the BMP
* It is particularly important to know about these three lab tests. You can help speed up a patient’s ED course by carefully tracking these labs and frequently checking for results. These three labs are often “rate-limiting steps” so it is vital to closely monitor their status and share the results with the MD as soon as possible.
A High D-Dimer – Significance
Must order CTA Chest or VQ Scan
– (First need Creatinine from BMP before CTA)
A High Trop (Troponin) – Significance
Acute MI: give ASA, NTG, ß-Blocker, Heparin
A >1.4 Creat (Creatinine) from the BMP – Significance
Assesses kidney function.
Creatinine must be obtained prior to ordering any CT with IV contrast due to IV contrast stressing the kidneys.
Any pt with a Creatinine >1.4 cannot receive IV contrast.
Emergency Labs – Summary
- CBC w/ Diff (Complete Blood Count) — Infection (WBC) or anemia (Hgb + Hct = H&H)
- BMP (Basic Metabolic Panel) — Electrolytes (Na + K), Renal function (BUN + Creat), Glucose
- CMP (Complete Metabolic Panel) — BMP + LFT’s (liver function)
- Trop (Troponin) – Acute MI (if high)
- uDip + UA (Urinalysis) — UTI or blood (possible kidney stone)
- BNP (B-type Natriuretic Peptide) — Acute CHF (if high)
- Coags (PT/INR/PTT) — Risk for bleeding (if high)
- ABG (Arterial Blood Gas) — Respiratory function (hypoxia?)
- D-Dimer — Possible blood clot (if high, need Creat for CTA Chest)
Consultations are usually completed for 3 reasons.
- The ED doctor needs to admit a patient to the hospital.
- The ED doctor needs specialist advice regarding a particular disease, treatment, or need for follow-up.
- The ED doctor calls the patient’s PCP to inform them their patient was evaluated in the ED.
Consultation — General Format
- Timestamp
- Name of the provider being consulted
- The specialty of the provider being consulted
- What was discussed
Examples:
15: 35. Spoke with Dr. Martin (Cardiology). Discussed case, will provide consult.
09: 45. Discussed case with Dr. Charles (Internal Medicine). Agrees with the plan, will admit.
When do re-evaluations occur?
When the provider re-checks a patient to determine whether their status is improving, unchanged or worsening.
Re-evals are performed on almost every patient in the department, and most commonly happen for 5 reasons:
- The patient is about to be discharged and the doctor needs to share the discharge instructions, ensure the patient’s symptoms have improved, and check that the pt iS stable to be discharged
- The patient is about to be admitted and the doctor needs to update the patient on the plan to admit, and check on the patient’s symptoms and status.
- The pt needs abnormal vital signs re-checked (HR, BP, SaO2, Temp)
- A particular physical exam finding needs to be re-checked.
- Repeat abdominal exam; have any peritoneal signs developed?
- Repeat neurological exam; have any neurological deficits improved or worsened?
- Repeat auscultation of lungs; has the lungs’ air movement improved or worsened?
- The doctor needs to determine if a particular treatment was effective.
- Is the patient’s pain better after analgesics (e.g. Toradol or Dilaudid)?
- Is the patient’s fever lower after antipyretics (e.g. Tylenol or Motrin)?
- Did the patient stop vomiting after antiemetics (e.g. Zofran or Phenergan)?
- Did the patient’s wheezing improve after bronchodilators (e.g. Albuterol Nebulizer)?
Example Re-Evaluations
Time Stamp. Re-evaluation. Patient feels [better/unchanged/worse] after [Objective assessment or plan].
- The patient feels better after_____. Stable for discharge at this time. Discussed return indications and the importance of follow-up.
- The patient feels better after______. Patient in NAD. Will continue to monitor, pending
- The patient feels unchanged after_____. Exam is unchanged. Will order additional
- The patient felt no improvement after______. Will try (different medication).
- The patient’s pain iS worsening. Will give additional (analgesic).
Examples:
15: 35. Re-check. Pt feels better after Zofran. Tolerating PO fluids well. Stable for DC.
09: 45. Re-evaluation. Pt feels unchanged after DuoNeb. Repeat auscultation still demonstrates wheezing. Will order additional DuoNeb.
18: 02. EP at bedside. Pt’s pain is unchanged after Motrin. Distal CSMT remains intact. Will give Morphine as additional analgesic.
