Lab Values

Clinical Relevance of Lab Values and Vitals

Abnormal levels in electrolytes, fluid balance, blood values (hematology), ABGs, enzymes, and vital signs can negatively impact a patient’s:

Activity tolerance

Cognitive function

Functional mobility

PT Implications regarding Lab Values

Assists in determining current patient presentation and clinical observation during examination and treatment

Also guides intervention appropriateness, intensity, duration, safety and effectiveness

Should a PT rely exclusively on lab values for clinical decision making, T or F?

False

Electrolyte Panel

K+, Na+, Cl-, CO2, pH

Fluid balance, acid-base status, neuromuscular function

Basic Metabolic Panel (BMP)

Electrolytes (K⁺, Na⁺, Cl⁻, CO₂), Glucose, Blood Urea Nitrogen (BUN), Creatinine (Cr)

Metabolic status, kidney function, hydration

Complete Blood Count (CBC)

White Blood Cells (WBC), Red Blood Cells (RBC), Hemoglobin (Hg), Hematocrit (Hct), Platelets (Plt), WBC Differential

Infection, anemia, clotting risk

Coagulation Profile

Prothrombin Time (PT), Partial Thromboplastin Time (PTT), Activated PTT (aPTT), International Normalized Ratio (INR)

Clotting status, bleeding risk

Cardiac Panels

Troponins, Creatine Kinase-MB (CK-MB), Brain Natriuretic Peptide (BNP), C-reactive Protein (CRP)

Cardiac damage, heart failure, systemic inflammation

Kidney Function

BUN, Creatinine

Renal clearance, fluid/electrolyte management

Liver/hepatic Profile

ALT (Alanine Aminotransferase), AST (Aspartate Aminotransferase)

Liver cell injury, metabolism, detox function

Hemoglobin

Men: 14–18 g/dL

Women: 12–16 g/dL

Carries oxygen in the blood

Hematocrit

Men: 42–52%

Women: 37–47%

Measures % of RBCs in blood volume

WBC

Normal: 5,000–10,000/mm³

Immune defense; elevated in infection or inflammation

Platelets

Normal: 150,000–400,000/mm³

Blood clotting and wound repair

PT Implications for Hematology Value

Don't rely solely on lab numbers — clinical signs and symptoms often provide more actionable insight than isolated values.

Systems Based Approach

Determining if activity is appropriate, while monitoring symptoms and collaborate with interprofessional team

Signs and Symptoms carry more weigh than what?

Isolated lab values in clinical decision making

Key Action of a PT

Modify or delay interventions if clinical presentation suggests risk, even if lab values are borderline

Hemoglobin Values for Therapy >10 g/dl

Therapy as indicated

Hemoglobin Values for Therapy 8-10 g/dl

Poor cardiopulmonary reserve, Orthostatic hypotension, Tachycardia, Exercise intolerance, Pallor

Monitor vitals closely — especially SpO₂ and HR for tissue perfusion

Hemoglobin Values for Therapy <7-8 g/dl

Therapy may be contraindicated, use systems based approach, blood transfusion probable

Hemoglobin Values for Therapy <5-7 g/dl

Heart failure and death, blood transfusion likely, PT def probably be contraindicated, immediate medical management needed

Hemoglobin Values for Therapy 20 g/dl

Risk of hyperviscosity, capillary blockage, tissue ischemia

Low Hemoglobin w/ Chronic Conditions

CKD and Cancer Patients

Use a symptom-based approach for PT clearance, not just lab values

Low Hemoglobin w/ Post Op Surgery

Approx. 300 mL blood loss ≈ 1.5 g/dL drop in hemoglobin

Monitor post-op patients closely for:

Signs of anemia (pallor, SOB, dizziness), Orthostatic responses and endurance capacity

Low Hemoglobin w/ Fluid Dilution

Hemodilution (from IV fluids, blood products, or resuscitation) can falsely lower Hgb readings

Hematocrit <25% Guidelines

Only light ROM, isometrics – avoid aerobic or resistance work

Hematocrit >25% Guidelines

Light exercise, symptom-based approach (monitor for fatigue, dizziness)

Hematocrit >30-35% Guidelines

Ambulation and resistance training as tolerated

Anemia Causes

Acute blood loss, destruction or decreased production of RBCs

Anemia S/S

Paleness, weak, easily fatigued, dyspnea on exertion, rapid/shallow pulse

PT Implications for Anemia

Frequent vitals monitoring, consider Orthostatic Hypertension, fall risk reduction,

Use symptom-based progression and activity pacing

May need to delay treatment if transfusion is pending

PT Implications for Erythocytosis/Polycthermia Causes

Myeloproliferative disorders, Chronic hypoxia (e.g., COPD, heavy smoking, high altitude), chronic lung disease and congenital heart disease

Myeloproliferative Disorders

Myeloproliferative disorders are a group of chronic bone marrow diseases where the marrow produces too many blood cells — red cells, white cells, or platelets — often without normal regulation

Erythocytosis S/S

Headache, dizziness, blurry vision

Cognitive changes, decreased mental acuity, sensory changes (hands/feet), Risk of capillary blockage and tissue ischemia

PT Implications for Erythocytosis

Higher risk for CVA (stroke) and clot formation, Monitor neuro status, sensory changes, and avoid dehydration

Be cautious with vigorous activity that may increase clot risk

Leukocytosis

WBC > 10,000/mm³

Too many WBCs → sign of inflammation/infection or malignancy

Leukocytosis Causes

Infection, Leukemia, PNA, neoplasm, inflammation, tissue necrosis

Leukocytosis S/S

Fever, chills, sore throat, fatigue

Leukocytopenia

WBC < 5,000/mm³

Too few WBCs overall → less immune defense

Leukocytopenia Causes

Bone marrow failure, chemo/radiation, HIV, autoimmune conditions

Leukocytopenia S/S

Stiff neck, sore throat, fever/chills, mouth ulcers, Increased infection risk

Neutropenia

Neutrophils < 1,500/mm³

A specific type of leukocytopenia — low neutrophils (front-line defense against bacterial infection)

Neutropenia Precautions

Reverse isolation (protect the patient)

Patient must wear a mask if leaving room

Therapist must wear a mask; do not treat if sick

No fresh fruit or flowers (infection control)

Platelets

Cytoplasmic fragments of megakaryotcytes in bone marrow

Functions in hemostasis and initiating clotting mechanism

Normal Range is 150-400,000/mm^3

Thrombocytosis Causes

Infection, inflammation and genetic myeloproliferative conditions

Thrombocytosis Risks

Increased risk for thrombosis (clotting) and paradoxical risk for bleeding

Thrombocytosis Symptoms

weakness, headache, dizziness, chest pain, tingling in hands/feet

Thrombocytopenia Causes

(<150,000/mm³)

Bone marrow suppression (e.g., leukemia, chemotherapy)

Cytotoxic drugs

Thrombocytopenia Risks

Increased risk for bleeding, avoid bumps, bruising, avoid resistive exercises due to intramuscular bleeding and avoid valsalva maneuver

Thrombocytopenia Symtoms

Brusing, epistaxis, hematuria, oral bleeding, and petechiae

Thrombocytopenia Guidelines for 20-50,000/mm^3

AROM exercise w/ or w/o resistance and ambulation as tolerated

Thrombocytopenia Guidelines for <20,000/mm^3

Therapeutic exercise only without resistance

High risk of spontaneous bleeding

Petechiae

Ecchymosis

Prolonged bleeding times

Thrombocytopenia Guidelines for <10,000/mm^3 or temp >100.5

Risk for spontaneous CNS, GI, or respiratory tract bleeding

Physical Therapy contraindicated

Purpose of Blood Transfusion

Replete blood volume, maintain O2 delivery to tissues and maintain proper coagulation

Blood Transfusion Timing

Typically takes 3-4 hours per unit

How many minutes should you hold therapy until patients can you do therapy?

First 15 minutes of transfusion, no contraindication to PT otherwise

Defer out-of-bed activity depending on... for transfusion

Vital signs

Patient condition

Active symptoms

Symptoms of Transfusion-Related Immunomodulation

Tachycardia, cough, dyspnea, crackles, headache, HTN, distended neck veins, fever, rash, and hypotension

Blood Transfusion Precautions

Mobility, fall risk and monitor vitals

Prothrombin Time (PT)

Normal: 11-13.5 sec

Examines the function of the extrinsic system in clotting cascade, monitored with Coumadin (warfarin)

International Normalized Ratio (INR)

Normal Range: 0.9-1.1

Used to correct for differences in lab reagents used for testing Prothrombin time, also monitors Coumadin therapy

Partial Thromboplastin Time (PTT)

Normal Range: 60–70 seconds

Measures intrinsic + common pathways of clotting

Monitored with Heparin, Lovenox (Low molecular weight heparin)

Activated Partial Thromboplastin Time (aPTT)

Normal Range: 30–40 seconds

Faster version of PTT using an activator (results in <1 hour)

Still monitors Heparin and Lovenox

INR (International Normalized Ratio) Guidelines for PT (INR 2-3)

Therapeutic Goal (on anticoagulation like Coumadin): INR = 2.0-3.0

For patients like AFIB

INR Guidlines for PT (INR <4.0)

Avoid resistive exercise

Light exercise only (keep RPE < 11)

IF INR IS 5-6, Coumadin is held, what happens?

Evaluation only for D/C planning and determining level of functioning

Vitamin K or fresh frozen plasma for thicker blood

INR 5-9 Guidlines

Avoid excessive physical activity/bed rest, may do eval only for discharge planning or to determine current level of function, consult w team

INR Monitoring for Therapy

Blood pressure, HR, O2 saturation, blood counts, physical appearance, level of exertion, safety

Low INR

Low INR (<0.9) = Thicker blood → Higher clot risk

High INR

High INR (>3.0) = Thinner blood → Higher bleeding risk

Low Prothrombin Time

Low PT (<11 sec) = Faster clotting → Thicker blood, ↑ clot risk

High Prothrombin Time

High PT (>13.5 sec) = Slower clotting → Thinner blood, ↑ bleeding risk

Subtherapeutic Therapy

Coagulation level below 2, at risk for clotting, forming embolisms

Supratherapeutic Therapy

Coagulation Level above 3, at risk for bleeding, hemorrhage

Can be reversed with Vitamin K and Fresh Frozen plasma

D-Dimer

Normal: < 0.5 mg/L

Measurement of fibrin degradation

Confirms clot formation and breakdown has occurred

High levels of D-dimer associated with?

DVT, PE

Mobilization with Acute DVT

Unlikely to mobilize blood clot

Superficial vs Deep DVT

Superficial: less risk for embolism

Deep: higher risk for PE (Pulmonary Embolism)

Anticoagulation Therapy

Does not remove existing removing clot, it is preventive at reducing the risk of another clot

Signs and Symptoms for PE, DVT, CVA and MI

PE: sudden chest pain, cough, difficulty breathing,anxiety, LOC, increased RR, cyanosis, lightheadedness

DVT Prevention Interventions

Ankle Pumps: Encourage venous return

Ted Hose: graduated compression to prevent venous stasis

Sequential Compression Devices: inflate/deflate to mimic muscle pump

Pharma: Anticoagulants

60% of the body is made up of?

Water

Intra vs Extracellular Compartment

Intra: 2/3 of water in body

Extra: 1/3 of water in body

Extracelluar Compartment includes?

Interstitial Fluid (between cells)

Plasma (in blood vessels)

Transcellular Fluid (contained within specialized compartments)

Transcellular Fluid Examples

Ascites – fluid in the peritoneal cavity

Pleural effusion – fluid in pleural cavity (lungs)

Pericardial effusion – fluid around the heart

Hydrocephalus – excess CSF in brain ventricles

Anasarca – generalized body-wide edema (often due to liver/kidney failure or malnutrition)

Fluid Movement

Forces that control movement of water between capillary and interstitium that attempt to maintain capillary pressure

Capillary Hydrostatic Pressure

Pushes fluid OUT of the capillary into the interstitium

Capillary Colloidal Osmotic Pressure

Pulls fluid IN to the capillary from the interstitial space, mainly by albumin (proteins)

Interstitial Hydrostatic Pressure

Pushes fluid OUT of the interstitial space

Interstitial Colloidal Osmotic Pressure

Pulls fluid IN to the interstitial space

If filtration > reabsorption

EDEMA

If reabsorption > filtration

Dehydration of tissues

Increased Capillary Hydrostatic Pressure

Common Causes:

Congestive Heart Failure (CHF)

Hypertension

Venous obstruction (DVT)

Decreased Capillary Colloidal (Oncotic) Pressure

LOSS OF PROTEINS

Liver failure / Cirrhosis

Malnutrition / Starvation

Kidney disease (proteinuria)

Burns / Open wounds (loss of proteins)

Increased Capillary Permeability

Proteins and fluid leak into interstitial space → pulls more water out

Common Causes:

Burns

Acute inflammation

Immune or allergic responses

Obstruction of Lymphatic Flow

Lymphatic system fails to remove excess interstitial fluid

Common Causes:

Cancer (tumor obstruction)

Surgical removal of lymph nodes

Infections blocking lymph nodes

Hypovolemia

Decreased state of extracellular volume leads to reduced blood volume (plasma) and impaired perfusion

Hypovolemia Causes

Limited fluid intake leads to decreased thirst mechanism (CVA, dementia and older adults)

Excessive fluid loss (vomiting, sweating, burns, uncontrolled DM, diarrhea, fever)

Hypovolemia S/s

lightheadedness (decreased BP), dry mucus membranes, tachycardia (weak and rapid), poor skin turgor