1) Physiological Effects Summary

Modality Physiological Effects

Cryotherapy (Cold) ↓ tissue temperature → vasoconstriction, ↑ blood viscosity, ↓ metabolic rate & O₂ demand (prevents secondary hypoxic injury), ↓ nerve conduction velocity, reflex ↓ gamma motor neuron activity → ↓ muscle spasticity; may cause cyclic vasodilation (Hunting response).

Thermotherapy (Heat) ↑ tissue temperature (104–113 °F) → vasodilation, ↑ capillary permeability (mild inflammatory reaction), ↑ collagen extensibility, ↓ joint stiffness, ↓ pain via thermal Gate Control theory, ↓ Type II spindle activity & ↑ Ib (GTO) firing → ↓ α-motor neuron activity.

Intermittent Pneumatic Compression (IPC) ↑ tissue hydrostatic pressure → ↓ fluid loss from vessels, ↑ venous return, ↑ lymph drainage, ↓ edema and pain, may assist clot formation post-injury; enhances cooling effect if used with cold.

🔥❄ 2) Conduction vs Convection (Heat Transfer Type)

Mechanism Modality Examples Category

Conduction Ice pack, Ice massage, Cold pack, Moist Hot Pack, Paraffin bath Conduction = direct molecule-to-molecule heat exchange

Convection Cold whirlpool (with agitation), Fluidotherapy (dry heat) Convection = heat transfer through moving fluid or air

Evaporation (note) Vapocoolant spray (Biofreeze/Cold Spray) Heat loss as liquid → vapor

🧺 3) Moist Hot Pack Parameters (Layers & Safety)

Parameter Value / Guideline

Storage Temp (hydrocollator) 158–167 °F (≈ 70–75 °C)

Towel Layers 6–8 layers standard (Hot pack cover = 2 layers → add ≥ 4 towels); 8–10 layers if patient lies on pack

Treatment Time 15–30 min (first use 10–15 min; re-check ≈ 5 min)

Safety Pearl Never remove layers even if heat feels “not hot enough”; educate patient about burn risk

⚠ 4) Indications / Contraindications / Precautions

Modality Indications (When to Use) Contraindications (Do NOT Use) Precautions (Use with Care)

Cryotherapy Acute trauma (↓ bleeding & metabolism), Post-op swelling & pain, Pain control, Spasticity (CVA/CP/MS), Trigger points, DOMS Cold urticaria, Cryoglobulinemia, Raynaud’s, Paroxysmal cold hemoglobinuria, Compromised circulation/PVD, Over regenerating nerves, History of frostbite, Severe CV/resp conditions HTN (monitor BP), Cold sensitivity, Impaired sensation/cognition, Over superficial nerves (e.g., peroneal), Young or elderly patients

Thermotherapy Subacute/chronic conditions to ↑ tissue extensibility & ↓ pain or guarding Impaired temp sensation, Severe vascular insufficiency, Recent burns, Infection, Malignancy, Acute inflammation/injury, Cognitive impairment, BP > 160/90, Thin skin (from steroids) Pregnancy (systemic heat risk), Poor heat dissipation (SCI), Monitor for dizziness or burn signs

Compression / IPC Post-op or post-trauma edema, Venous insufficiency, Lymphedema, DVT prevention, PAD ischemia trials, Venous stasis ulcers Acute pulmonary edema, CHF, Recent or acute DVT, Acute fracture, Uncontrolled HTN Recent skin graft, Acute skin infection, Impaired sensation/mentation; monitor for SOB, N/T, new swelling

🩺 5) Determining Maximum IPC Pressure

Base limit on patient’s diastolic BP (DBP).

→ Max = ≈ DBP − 10 mmHg (to avoid vascular occlusion).

General Ranges:

Edema (post-acute): 40–50 mmHg comfortably safe

Lymphedema: 30–60 mmHg (~1 h)

DVT prophylaxis: 30–50 mmHg (1:4 cycle, continuous)

PAD research: up to 120 mmHg (distal→proximal sequence, specialized use)

Initial injury (<48 h): avoid high pressures — may worsen tissue damage.

📏 6) Most Common Objective Measure for IPC Effectiveness

✅ Girth measurements or Volumetrics (pre- & post-treatment) are the primary objective outcomes to quantify edema reduction.

Supporting measures: VAS (pain), Goniometry (ROM), Functional tests (gait/AROM).

✅ Quick Recall Sheet

Topic Key Number / Concept

Cryotherapy target temp < 10 °C (50 °F) may trigger Hunting response

Thermotherapy target temp 104–113 °F = vigorous heating range

MHP Layers 6–8 (8–10 if supine)

IPC Pressure Range 30–75 mmHg (≤ DBP − 10 mmHg)

IPC Cycle 1:1 (30–60 s on/off)

IPC Measure of Effect Girth / Volumetric change