Cryotherapy Lecture Notes PDF

Cryotherapy DPT 5540 – Biophysical Agents DPT 5540/Dr. Holmes  Lecture Objectives Understand basic physical principles of cryotherapy Understand biophysical principles of tissue cooling Recognize indications, contraindications, and preca...

Cryotherapy DPT 5540 – Biophysical Agents DPT 5540/Dr. Holmes  Lecture Objectives Understand basic physical principles of cryotherapy Understand biophysical principles of tissue cooling Recognize indications, contraindications, and precautions for cold therapy Know the different methods of providing cold therapy Effectively assess outcomes following treatment DPT 5540/Dr. Holmes  Clinical Scenario 17 year-old-female soccer player twisted her ankle while making a sharp turn on the field. The mechanism of injury involved plantar flexion and inversion of the right ankle and occurred yesterday. The ankle is edematous and warm to touch around the right lateral malleolus.  What structure appears to be involved?  Would you choose hot or cold? Why?  What specifically would you use and why? DPT 5540/Dr. Holmes  What are the CryoTherapy Agents? DPT 5540/Dr. Holmes  Cooling Cooling – transfer of thermal energy Heat always moves toward cool or cold DPT 5540/Dr. Holmes  Cooling Modes for energy transfer  Conduction  Cold or ice packs  Ice massage  Controlled cold units  Cool or cold immersion  Convection  Cold immersion (with agitation)  Evaporation  Vapocoolant spray DPT 5540/Dr. Holmes  Physical Principles of Cryotherapy: Conduction The transfer of heat by direct interaction of molecules (e.g., cold pack) DPT 5540/Dr. Holmes  Conduction D = (Area) x k x (T1 – T2)/(thickness of tissue) Factors  Temperature difference  Time of exposure  Thermal conductivity  Type and size of cooling agent  Total body surface area cooled  Activity level  Ability of cooling agent to maintain temperature Local effects DPT 5540/Dr. Holmes Which Conduction of Energy Happens Faster? DPT 5540/Dr. Holmes  Conduction Why? After cooling, area may not rewarm rapidly Greater the target tissue depth, longer takes for cold application to lower the temperature Skin cools very rapidly Form in which cold applied can contribute to degree of cooling DPT 5540/Dr. Holmes Jutte, et al. The relationship between intramuscular temperature, skin temperature, and adipose thickness during cryotherapy and rewarming. Archives of Physical Medicine and Rehabilitation. Volume 82, Issue 6, Pages 845-850 (June 2001) DPT 5540/Dr. Holmes  Physical Principles of Cryotherapy: Convection Heat abstraction by direct contact between the skin and moving fluid particles (e.g. cold whirlpool)  Heat abstraction occurs at a faster rate with convection versus conduction  Practical only for distal extremities  Dependent position DPT 5540/Dr. Holmes  Physical Principles of Cryotherapy: Evaporation Energy is absorbed (heat) and changes from a liquid to a vapor  Vapocoolant sprays (e.g. Spray and Stretch, Instant Ice)  Trigger points, stretching  Effects: ↓ skin temperature, ↓ motor neuron activity  Negligible effects on deeper tissues DPT 5540/Dr. Holmes  Inflammatory Response Phase Signs and symptoms  Redness, swelling, tenderness, increased temperature, loss of function Cellular Response  Leukocytes, phagocytic cells Chemical Mediators  Histamine, leukotrienes, cytokines Vascular Reaction  Initial response vasoconstriction, then vasodilation DPT 5540/Dr. Holmes DPT 5540/Dr. Holmes  Chronic Inflammation Acute inflammatory response not sufficient to eliminate injuring agent and restore tissue Neutrophils are replaced with:  Macrophages, lymphocytes, fibroblasts, plasma cells DPT 5540/Dr. Holmes  Fibroblastic-Repair Phase Signs and Symptoms  Mild tenderness, pain with particular movements Revascularization  Blood vessels regrow, increase blood flow, nutrients Formation of Scar  Formation of granulation tissue  Fibroblasts, collagen, capillaries DPT 5540/Dr. Holmes  Maturation-Remodeling Phase Realignment or remodeling of collagen fibers Ongoing breakdown and synthesis of collagen with increase in tensile strength of scar matrix Fibers realign in position of maximum efficiency parallel to lines of tension DPT 5540/Dr. Holmes  Biophysical Principles of Tissue Cooling Cold used in management of acute trauma because:  Resulting arteriolar vasoconstriction reduces bleeding  ↓ in metabolism and vasoactive agents reduce inflammation  Pain threshold is elevated DPT 5540/Dr. Holmes  Biophysical Principles of Tissue Cooling Hemodynamic effects  Reflex vasoconstriction  ↓ blood flow  ↑ viscosity  When tissue temperature below 10° C (50° F), cyclical vasodilation, vasoconstriction (not fully verified) DPT 5540/Dr. Holmes  Effect on Local Blood Flow ¯ Histamine & bradykinin ¯ vasodilation Vasoconstricti  Smooth Muscle Tone  Blood Flow on Cold Dorsal Root ganglion simulation  Blood Viscosity DPT 5540/Dr. Holmes  Biophysical Principles of Tissue Cooling Post-traumatic edema and inflammation (24–48 hours after injury)  ↓ Fluid filtration into interstitial fluid  ↓ Inflammation, pain, local metabolism  ↓ Intramuscular pressure  ↓ Local metabolism/ Energy demands  Decrease in secondary hypoxic tissue injury  ↓ Accumulation of leukocytes  Moderate cooling best (several hours or less)  Combine with compression and elevation DPT 5540/Dr. Holmes  Biophysical Principles of Cooling Effect on skin  Analgesic effect (sensitivity reduction) on superficial sensory receptors as well as conduction failure.  50% reduction in receptor sensitivity at 27° C (80.6° F)  Complete nerve block at 8-10° C (46.4 – 50° F)  No sensitivity to pressure and touch at 5° C (41° F)  Stages of Cold  Cold  Burning  Aching  Numbness DPT 5540/Dr. Holmes Biophysical Principles of Tissue Cooling Muscle performance effects  Short duration – no effect/slight ↑  Long duration – significant ↓  ↓ strength, proprioception, agility  Consider timing of evaluation and impact of cryotherapy on activity/exercise/intervention performance  Neuromotor control impacted  Can affect proprioception – balance/safe performance of functional activities can be hindered  Can dampen reflexes and clonus DPT 5540/Dr. Holmes  Biophysical Principles of Tissue Cooling Peripheral nerve effects  ↓ temp of nerve = ↓ sensory and motor conduction velocity  Synaptic transmission is decreased or blocked  ↑ pain threshold, ↑ pain tolerance   threshold for depolarization  Extreme cold can block nerve conduction  Longer cooling is applied longer it takes for nerve velocity to recover  Cannot cool sensory in isolation – consider effects on motor nerves as well DPT 5540/Dr. Holmes  Biophysical Principles of Tissue Cooling Neuromuscular effects  ↓ spasticity  Decrease gamma-moto neuron activity through stimulation of cutaneous afferents  Decrease in afferent spindle discharge by cooling muscle  Reduce clonus  Management of some neurological conditions DPT 5540/Dr. Holmes  Clinical Indications for Cold Therapy Primary Goals with Use of Cold Therapy  Limit edema formation  Reduce pain  Facilitate muscle relaxation  Limit secondary hypoxic tissue injury DPT 5540/Dr. Holmes  Clinical Indications for Cold Therapy Acute musculoskeletal trauma  PRICE – 20–30 minutes, several times/day  Over casts and bandages (longer duration) Pain and muscle spasm  Cold may act as counterirritant  Questionable benefits with Delayed-Onset Muscle Soreness (DOMS)  Limited literature about benefits with DOMS  Also, Inconsistent findings in literature Myofascial pain syndrome  Trigger Point Spasticity DPT 5540/Dr. Holmes  Guidelines for Cryotherapy Consider – accessibility, body part, compression and elevation required, size of area PMH: time since injury, hypersensitivity Avoid excess stresses to area  1–2 hours post-treatment  Including MMT 20–30 minutes, intermittent  Expected outcomes: numbness, redness Inform patients about what to expect  Explain that before they feel numbness, they will feel cold, burning, aching and that these sensations can often decrease in their intensity with repeated cold application DPT 5540/Dr. Holmes DPT 5540/Dr. Holmes  Contraindications for Cryotherapy Cold hypersensitivity/Cold urticaria Cryoglobulinemia Hemoglobulinemia Raynaud’s phenomenon Paroxysmal cold hemoglobinuria Deep Vein Thrombosis Anterior Neck Carotid sinus Hemorrhagic conditions Impaired circulation Over areas of nerve regeneration DPT 5540/Dr. Holmes  Contraindications for Cryotherapy Chronic Wounds Hypertension  If using systemic cold Infection (if using systemic cold or cold over site of infection) Tuberculosis Impaired cognition or communication DPT 5540/Dr. Schulken Precautions for Cryotherapy Hypertension Impaired sensation Damaged or at risk skin Thermoregulatory disorders Over superficial nerves Open wounds Very young or old DPT 5540/Dr. Holmes  No Contraindications/Precautions Tissues over active epiphysis Intact skin overlying implants containing metal, plastic or cement Skin overlying electronic devices Low back and abdomen of pregnant women Recently radiated tissues Reproductive organs Areas affected by skin diseases Chest, heart, and head Inflamed tissues recent injury DPT 5540/Dr. Holmes  Methods of Providing Cryotherapy Cold packs or ice packs  Frozen peas, homemade ice bag Ice massage  Intense cold, burning, aching, analgesia Vapocoolant spray Manual and electric cold compression units Cold baths Cold gels – perceived cold DPT 5540/Dr. Holmes  Methods of Providing Cryotherapy Cold Packs/Ice Packs Inexpensive: purchased or home made  Ice, ice plus water, frozen peas, water plus alcohol, gel, or chemicals  Homemade (Water and isopropyl alcohol; 2:1 – 4:1 ratio)  Remains pliable, cools as effectively as crushed ice over 20-minute period  Can reach temperatures colder than ice Must use toweling over the skin for any agent that has the ability to reach temperatures below 30°F (– 1.11°C)  Damp towels are superior to dry towels in facilitating energy transfer  Towel wet with room-temperature or lukewarm water, will be more comfortable with the initial contact with the skin DPT 5540/Dr. Holmes  Methods of Providing Cryotherapy Ice Massage Inexpensive  Water frozen in paper cups  Ice “lollipops” – using a tongue depressor in the cup Typically performed over a small area  E.g., over a muscle belly, tendon, or bursa) or over trigger points before deep pressure release or massage  10 cm x 15 cm area (4” x 6”) can be covered in 5-10 minutes  Slowly rub ice over the skin using small overlapping circles or strokes (5-7 cm/second)  Do not allow melted water to run onto areas not being treated Simple and can be taught for home use DPT 5540/Dr. Holmes  Methods of Providing Cryotherapy Vapocoolant Spray Spray and stretch (~$60-75), Instant Ice (~$25-38) Counter irritant to thermal afferents that overlie targeted muscle  Reduction in motor neuron activity and allowing stretch/TrP release Spray is applied:  In a few sweeps across the skin, 12-18 inches away from skin  Spray in unidirectional sweeps Temperature:  Of spray upon contact is 16°F to –4°F (-8.89°C to -20°C)  depending on distance of the nozzle from the skin  Skin temperature can drop to ~ 59°F (15°C)  for a few seconds  changes in subcutaneous tissue and muscle temperatures are negligible DPT 5540/Dr. Holmes  Methods of Providing Cryotherapy Ice/Cold Bath Practical for distal extremities Water temperatures  Typically vary from 50°F to 64.4°F (10°C to 18°C)  The lower the temperature range, the shorter the duration of immersion is required  Remember would be conduction without agitation of water ?? What would it be if the water particles moved over the skin? ?? How could this occur? Treatment time, usually 5-8 minutes Can be used at home with proper instructions DPT 5540/Dr. Holmes  Methods of Providing Cryotherapy Manual and Electric Cold Compression Units Manual cold compression  Circulation of cold water through a cuff that is applied over an extremity  Variety of sizes and shapes of cuffs and sleeves  Sleeves conform to any joint or extremity  To recirculate cold water into the cuff, the insulated ice- water-filled container is connected to the cuff by a hose and then elevated, allowing gravity to pull water into the cuff  Compression is achieved by pressure exerted from the filled cuff wrapped around the joint/extremity and secured with Velcro. Continuous cold compression units  Use electric pump to circulate water at intervals/rates that can be set  Water temperatures can be adjusted DPT 5540/Dr. Holmes  DPT 5540/Dr. Holmes Ice Burns DPT 5540/Dr. Holmes  Selecting a Cooling Agent Consider body area How much body surface to be covered DPT 5540/Dr. Holmes  Conductive Cooling In general, administered 20-30 minutes Intermittent cold To cool musculature tissue  Patients should refrain from activity while cold modality is applied DPT 5540/Dr. Holmes  General Method for Application Perform appropriate evaluation: history, co-morbidities, age, inspection of treatment area Determine appropriate goals for intervention Remove jewelry and clothing from the area to be effected Explain procedure and expectations Insure the patient’s comfort Apply the modality accordingly Provide bell / call button for safety Check on patient periodically Inspect area after completion of treatment Appropriately document: parameters used, area treated, patient response, skin appearance DPT 5540/Dr. Holmes  Assessment of Effectiveness and Expected Outcomes Edema ― girth measurements, volumetrics Pain – VAS scale ROM – goniometric measurements Functional movements ― gait, AROM Muscle guarding DPT 5540/Dr. Holmes  Assessment of Effectiveness and Expected Outcomes Documentation  Type of cold agent (and purpose)  Treatment duration  Site of application  Position of patient – compression and elevation?  Skin appearance  Patient response (pain, edema)  Outcome measures  Adverse responses (or lack of) DPT 5540/Dr. Holmes  Cryotherapy in Tissue Healing Common treatment in initial inflammatory response Few studies to determine optimal parameters Reduce edema, speed up healing process No evidence promotes healing beyond inflammatory phase DPT 5540/Dr. Holmes  Cryotherapy in Pain Management Can reduce blood flow and prevent excessive release of chemical mediators Increase pain threshold Tissue cooling reduces nerve conduction velocity, inhibits nociceptors, decreased muscle spasms DPT 5540/Dr. Holmes  Clinical Controversies How many hours/days after injury? How many minutes following acute trauma? Used after exercise? Used after heat and stretch? Elevation vs. elevation + compression vs. cold + compression  Which technique is most effective? DPT 5540/Dr. Holmes  Whole Body Cryotherapy What is it?  A chamber with -110 to -250 deg temps  Stay for 2-3 minutes  Does it work?  2016 FDA – “lacks evidence”  Wilson, et al. 2018  WBC had “harmful” effect compared to CWI or no cold  Gizinska, et al. 2015  RA pts no difference from traditional Rx  Rose, et al. 2017  Following exercise decreased pain and recovery time DPT 5540/Dr. Holmes  Clinical Scenario 17 year-old-female soccer player twisted her ankle while making a sharp turn on the field. The mechanism of injury involved plantar flexion and inversion of the right ankle and occurred yesterday. The ankle is edematous and warm to touch around the right lateral malleolus. She is two days out from her injury. DPT 5540/Dr. Holmes  Clinical Decision Making Does the patient have a dysfunction, limitation, or problem that can be improved with the use of cryotherapy? Patient appropriate for cryotherapy? What are the specific goals to be achieved with use of cryotherapy? What specific form of cryotherapy would be appropriate for the patient? What specific parameters of the form is appropriate? DPT 5540/Dr. Holmes  Summary Tissues can be cooled via conduction, convection, or evaporation. Cryotherapy has effects on various tissues. Select a cooling agent utilizing clinical decision making. Consider: indications, past medical history, area to be treated, contraindications, precautions, patient preference, availability. Assess outcomes after treatment and document appropriately. DPT 5540/Dr. Holmes Top Take Aways DPT 5540/Dr. Holmes