Skip to main content
Medicine LibreTexts

39.0: Appendix A- Diagnostic Studies and Interpretation

  • Page ID
    111739
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \( \newcommand{\dsum}{\displaystyle\sum\limits} \)

    \( \newcommand{\dint}{\displaystyle\int\limits} \)

    \( \newcommand{\dlim}{\displaystyle\lim\limits} \)

    \( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

    ( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\id}{\mathrm{id}}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\kernel}{\mathrm{null}\,}\)

    \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\)

    \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\)

    \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    \( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

    \( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

    \( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vectorC}[1]{\textbf{#1}} \)

    \( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

    \( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

    \( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)

    Diagnostic tests and procedures are used in clinical health-care settings to aid in the identification of a condition, disease, or prognosis with a high degree of accuracy. They are crucial to early detection and application of the proper treatment plan for each patient. Every provider is responsible for the analysis of each study and the individual action plan because of the interpretation. Every diagnostic has four phases. The first is to determine normal or acceptable ranges of the test. The second is to evaluate the accuracy of the test. The third is to determine clinical consequences of the results of the test. The fourth is to evaluate if more diagnostics are needed before determining an individual plan. Table A1 lists common laboratory tests and expected results. Table A2 displays commonly used diagnostic studies for providing competent and comprehensive patient care.

    Serum, Plasma, and Whole Blood
    Red blood cell (RBC) 4.5–5.0 million cells/mm3 (female)
    4.7–6.2 million cells/mm3 (male)
    White blood cell (WBC) 4,500–11,000 cells/mm3
    Platelets 150,000–400,000/mm3
    Blood urea nitrogen (BUN) 6–24 mg/dL
    Serum creatinine 0.6–1.2 mg/dL
    Estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73m2
    Carbon dioxide 23–29 mmol/L
    Glucose 65–110 mg/dL
    Aldolase 22–59 mU/L
    Chloride 95–105 mEq/L
    Potassium 3.5–5.2 mEq/L
    Sodium 135–145 mEq/L
    Calcium 8.3–10.2 md/dL
    Phosphorus 3.0–4.5 mg/dL
    Magnesium 1.3–2.1 mEq/L
    Serum osmolality 285–295 mOsm/kg H2O
    Albumin 3.5–5.5 g/dL
    Total protein 5.5–8.3 g/dL
    Bilirubin 0.1–1.2 mg/dL
    Ammonia 11–32 mcmol/L
    Aspartate aminotransferase (AST) 9–25 units/L (female)
    10–40 units/L (male)
    Alanine aminotransferase (ALT) 7 – 20 units/L (female)
    10 – 55 units/L (male)
    Copper 70–15 mcg/dL
    Ferratin 18–160 ng/mL (females)
    18–270 ng/mL (males)
    Folic acid 3–13 ng/mL
    Arterial Blood Gas (ABG)
    pH 7.35–7.45
    Partial pressure of oxygen (PaO2) 80–100%
    Partial pressure of carbon dioxide (PaCO2) 35–45 mmHg
    Bicarbonate (HCO3) 22–26 mEq/L
    Hematology
    Fibrinogen 200–400 mg/dL
    Erythrocyte count 3.6–5.0 × 1012/L (female)
    4.2–5.4 × 1012/L (male)
    ESR 0–20 mm/h (females less than 50 yrs)
    0–30 mm/h (females greater than 50 yrs)
    0–15 mm/h (males less than 50 yrs)
    0–20 mm/h (males greater than 50 yrs)
    Hematocrit 36–48% (female)
    42–52% (male)
    Hemoglobin 12–16 g/dL (female)
    13–17 g/dL (male)
    International normalized ratio (INR) 0.8–1.2
    2–3 is normal for patients on warfarin
    Prothrombin time (PT) 11–13 seconds
    1.5–2× longer if on anticoagulants
    Partial thromboplastin time (PTT) 60–70 seconds
    1.5–2× longer if on anticoagulants
    Activated partial thromboplastin time (aPTT) 25–35 seconds
    1.5–2× longer if on anticoagulants
    Cardiac Markers
    Total creatine kinase (CK) 500–2250 nkat/L (female)
    917–2833 nkat/L (male)
    Myoglobin 5–70 ng/mL
    Troponin <0.4 ng/mL
    Atrial natriuretic peptide (ANP) 22–77 ng/L
    Brain natriuretic peptide (BNP) <100 ng/L
    Lipid Panel
    High-density lipoprotein (HDL) > 40 mmol/L
    Low-density lipoprotein (LDL) < 100 mmol/L
    Triglycerides < 120 mmol/L
    Total cholesterol < 170 mmol/L
    Hemoglobin A1C
    Normal < 5.7%
    Prediabetes 5.7–6.4%
    Diabetes > 6.5%
    Proteins
    Protein total 6–8 g/dL
    Albumin 3.5–5.2 g/dL
    Globulin 1.7–3.3 g/dL
    Vitamins
    Vitamin A 30–120 mcg/dL
    Vitamin B1 1.6–4 mcg/dL
    Vitamin B6 5–30 ng/mL
    Vitamin B12 200–900 pg/mL
    Vitamin E 0.5–1.8 mg/dL
    Zinc 55–150 mcg/dL
    Urine Chemistry
    Ketones < 2.0 mg/dl
    Amylase 1–17 units excreted per hour
    Calcium 100–250 mg per 24/hour
    pH 4.5–8
    Osmolality 50–1200 mOsm/kg
    Glucose Negative
    Note: These values could change slightly based on parameters set by specific health-care facilities
    Table A1 Common Laboratory Tests
    Diagnostic Description
    Angioplasty Widens the arteries and increases cardiac blood flow
    Biopsy Removes a sample of tissue or cells from the body for microscopic examination to diagnose cancer or other diseases
    Bronchoscopy Examines the larger airways: trachea and bronchi
    Chest X-ray Evaluates the lungs, heart, or chest wall to diagnose pneumonia, heart failure, emphysema, lung cancer, and other medical conditions
    Colonoscopy Examines the colon, or large intestine
    Computed tomography scan (CT) Evaluates all major parts of the body, including the abdomen, back, chest, and head
    Electrocardiography (EKG or ECG) Records the heart’s electrical activity to detect abnormal rhythms, heart damage, or heart failure
    Electroencephalogram (EEG) Records the brain’s electrical activity
    Endoscopy Examines the inside of certain tube-like structures in the body with a fluoroscope; for example, upper GI series examines the esophagus, stomach, and duodenum
    Fecal occult blood test Examines stool samples for traces of blood; also called a stool guaiac or hemoccult test
    Lumbar puncture Uses a needle to remove a sample of fluid from the space surrounding the spinal cord to diagnose infections, such as meningitis, and some neurological conditions.
    Magnetic resonance imaging (MRI) Uses a magnetic field to produce pictures of structures inside the body
    Ultrasonography Uses high frequency sound waves to generate snapshots or moving pictures of structures inside the body, especially vital organs; also called sonography
    Ventilation-perfusion scan (V-Q scan) Nuclear scan that examines both airflow (ventilation) and blood flow (perfusion) in the lungs
    X-ray Uses waves of electromagnetic radiation to create images of organs and other structures inside the body
    Table A2 Common Diagnostic Procedures (Bolboacă, 2019)

    References

    Bolboacă S. D. (2019). Medical diagnostic tests: A review of test anatomy, phases, and statistical treatment of data. Computational and Mathematical Methods in Medicine, 2019, 1891569. doi.org/10.1155/2019/1891569

    Committee on Diagnostic Error in Health Care; Board on Health Care Services; Institute of Medicine; The National Academies of Sciences, Engineering, and Medicine; Balogh, E.P., Miller, B.T., & Ball, J.R., eds. (2015, Dec 29). Improving Diagnosis in Health Care. National Academies Press (US), The Diagnostic Process. www.ncbi.nlm.nih.gov/books/NBK338593/

    Gaines, K. (2023). NCLEX lab values nursing students need to know. https://nurse.org/education/lab-values-nclex/

    Kea, B., Hall, M. K., & Wang, R. (2019). Recognising bias in studies of diagnostic tests part 2: interpreting and verifying the index test. Emergency Medicine Journal: EMJ, 36(8), 501–505. doi.org/10.1136/emermed-2019-208447

    Martin, P. (2024). Complete normal lab values reference guide and cheat sheet. nurseslabs.com/normal-lab-va...-nclex-nursing /

    Queremel Milani, D.A., & Jialal, I. (2023 May 1). In Urinalysis. StatPearls [Internet]. www.ncbi.nlm.nih.gov/books/NBK557685/


    This page titled 39.0: Appendix A- Diagnostic Studies and Interpretation is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by OpenStax.

    • Was this article helpful?