Cryotherapy

Cryotherapy for Physiotherapy/health care students

1. Cryotherapy Dr Sreeraj S R, Ph.D.

2. Introduction Cryo means “cold or freezing” Cryotherapy refers to the practice of using cold to achieve therapeutic goals Cooling by cryotherapy agents mostly occurs by conduction except in case of vapocoolant spray and hydrotherapy where heat transfer occurs through evaporation and by convection receptively. 2

3. Physical Principles Solid form of ice into water i.e., latent heat of fusion. 1 gram of ice at 0ºC requires 336 Joules of energy to convert it into 1 gram of water at 0ºC, whereas 1 gram of water at 0ºC requires 155 joules of energy to convert it into 1 gram of water at 37ºC. Thus, for cooling the body tissues it is better to use ice for treatment rather than water. 3

4. Physiological Effects Body Temperature Hemodynamic effects Initial decrease in blood flow Later increase in blood flow Neuromuscular effects Decreased nerve conduction velocity Increased pain threshold Altered muscle strength Decreased spasticity Facilitation of muscle contraction Metabolic effects Decreased metabolic rate 4

5. Body Temperature The normal body temperature can be anywhere between 97°F (36.1°C) and 99°F (37.2°C) in different individuals. Cold causes fall in local body temperature. Hypothermia is a condition where the core temperature is below 35°C. It may be a life-threatening situation. 5

6. Hemodynamic effects Initial decrease in blood flow Later increase in blood flow 6

7. Initial decrease in blood flow 7 Temperature Vasodilator Release Blood Viscosity Stimulation of Cutaneous Thermoreceptors Smooth Muscle Contraction Sympathetic Adrenergic Activation Blood Flow through vasoconstriction

8. Later increase in blood flow Cold induced vasodilation Lewis’ hunting reaction Skin redness result of an increase in oxygen hemoglobin dissociation of blood 8

9. Lewis-Hunting reaction After a short periods of vasoconstriction there follows a vasodilation Which followed by alternate periods of constriction and dilatation. This apperent hunting for a mean point of circulation is called “ lewis’s hunting r eaction”. Reflex vasodilation following cold application was first recognized and reported by lewis , in 1930. 9

10. Lewis-Hunting reaction Cold-induced reflex vasodilation may occur at temperature below 10°C in a cyclic manner. Possible Reasons for Hunting reaction are believed to be ; Release of H-substance which initiates an axon reflex in response to pain from temperature 10°C. Opening of arteriovenous anastomoses under the influence of cold and shunting blood directly from the arterial to the venous vessels, bypassing the resistance of the capillary bed. 10

11. AVAs Arteriovenous anastomoses (AVAs) are direct connections between small arteries and small veins, with no capillary section between them. 11

12. Neuromuscular effects Decreased nerve conduction velocity Increased pain threshold Altered muscle strength Decreased spasticity Facilitation of muscle contraction 12

13. Decreased nerve conduction velocity Skin contains several times more cold than warm receptors. These cold receptors respond to cooling by a sustained discharge of impulses, the rate of which increase with further cooling. However, there is decreased conduction velocity of both sensory and motor nerves Greater effect on myelinated and small fibers like A- delta fibers followed by B and C fibers at moderate temparature . 13

14. Increased pain threshold Cryotherapy can increase pain threshold and decrease the sensation of pain Due to Counter irritation Gate control Reduction in muscle spasm Sensory nerve conduction velocity 14

15. Altered muscle strength Short duration cold exposure increases muscle strength due to Facilitation of motor nerve excitability Increased psychological motivation Long duration cold exposure decreases muscle strength briefly due to Reduced blood flow Slow motor nerve conduction Increased muscle viscosity Increased tissue stiffness Muscle strength shown to increase steadily from an hour later, to reach greater than cooling strength for the following 3 hours or later after a 30 minutes of cryotherapy. 15

16. Decreased spasticity As a reflex reaction to stimulation of cutaneous cold receptors there is; Decrease in gamma motor neuron activity, Decreased discharge of afferent spindle and Golgi tendon organ activity. Prolonged cooling for 10 to 30 minutes can reduce spasticity for the following 60 to 90 minutes, Were other therapeutic or functional activities can be carried out. 16

17. Facilitation of muscle contraction Facilitate alpha motor neuron activity to produce a contraction in a muscle that is flaccid due to UMN lesion Brief icing: Ice can be used to facilitate a muscle response, which uses a combination of coolness and pain sensation to produce the desired response. 17

18. Metabolic effects Decreased metabolic rate Cold decreases local metabolic rate and therefore can slow inflammatory activity. The concentration of pain-inducing toxic metabolites are reduced. It acts primarily by decreasing metabolic activity, thus leading to a reduction in inflammatory response, decrease in nociceptor excitability, nerve conduction velocity, and muscle contractility 18

19. Uses Inflammation control Edema control Pain control Modification of spasticity Facilitation/Rood’s technique Cryokinetics and cryostretch 19

20. Contraindications Cold hypersensitivity/cold induced urticaria Cold intolerance Cryoglobulinemia- aggregation of serum protein Paroxysmal cold cryoglobinuria Raynaud’s disease/digital cyanosis Regenerating peripheral nerve Local impaired circulation/peripheral vascular disease 20

21. Cold hypersensitivity/Cold Urticaria Hypersensitivity reaction of the skin to cold. Characterized by formation of welts which are red, extremely itchy.  Application of ‘ice cube’ to the skin of such people elicits a wheal and establishes the diagnosis. 21

22. Cold Intolerance Cold intolerance in the form of severe pain, numbness, and color changes in response to cold can occur in patients with some types of rheumatic diseases or after severe accidental or surgical trauma to the digits. 22

23. Cryoglobulinemia Not common Characterized by the aggregation of serum proteins in the distal circulation upon exposure to cold. These proteins can impair circulation, causing local ischemia and gangrene. This disorder may be associated with; Multiple myeloma, Systemic lupus erythematosus, Rheumatoid arthritis, Or other hyperglobulinemic states. 23

24. Cryoglobinuria Hemoglobin from lysed red blood cells is released into the urine in response to local or general exposure to cold. The main symptom displays is a change is in the  colour of the urine 24

25. Raynaud’s Disease In Raynaud phenomenon, blood-flow restriction occurs during cold temperatures and emotional stress. This may cause these areas to: Turn pale or white and then blue Feel numb, cold, or painful Turn red, throb, tingle, burn, or feel numb as blood flow returns to the affected areas 25

26. Before cryotherapy ask the Patient: “Do you have any unusual responses to cold?” “Do you develop a rash when cold?” (a sign of cold hypersensitivity) “Do you have severe pain, numbness, and color changes in your fingers when exposed to cold?” (signs of Raynaud disease or Raynaud phenomenon) “Do you see blood in your urine after being cold?” (a sign of paroxysmal cold hemoglobinuria ) 26

27. Regenerating peripheral nerve Cryotherapy should not be applied directly over a regenerating peripheral nerve because local vasoconstriction or altered nerve conduction may delay nerve regeneration. Ask the Patient for recent or ongoing nerve injury to the area. Test sensation before applying cryotherapy 27

28. Impaired Circulation Cryotherapy may aggravate the condition by causing vasoconstriction and increasing blood viscosity. Avoid cooling when edema is caused by poor circulation. Look for Skin temperature and color 28

29. Precautions Superficial main branch of a nerve Open wound Hypertension Poor sensation Very young and very old patients 29

30. Application Procedures Explain the modality to the patient. Prepare the bed by covering it with waterproof material. Adequately expose the part to be treated, protecting patient’s modesty. Inspect the skin overlying the treatment area. Position the patient in a neutral position. Apply the selected form of cryotherapy to the patient. Remind the patient what to expect from the cold application. It is common to first feel cold, then aching or burning, followed by numbness. re-check the patient after 3 to 5 minutes. At the end of treatment dry the area with the towel. Inspect the skin for responses to the treatment. 30

31. Application Methods Ice Towels Ice pack Ice Cube/cups Immersion Controlled compression units Vapocoolant sprays Excitatory cold 31

32. Ice Towels Dip a towel in a large bowl of cold water (2 parts of crushed ice to 1 part water) and squeeze it until it is just damp and applied to the part being treated. Change the towels every 30 seconds to 2 minutes. Total treatment time can be 15-20 minutes. Up to ten towels can be applied consecutively. In the presence of swelling, elevate the limb. The patient can exercise with the towels in position. When treating spastic muscle the towels are applied along the length of the muscle from its origin to its insertion. Little danger of producing an ice burn. 32

33. Ice Packs Commercial Easy storage and easy to apply. Fill the container with ice cubes/crushed ice and apply. 33

34. Ice Packs Home made Crushed or flaked ice may be placed inside a polythene cover. 34

35. Cold Packs Commercial Re-usable gel pack. 35

36. Cold Packs Home made Fill the freezer bag with 2 cups of water and 1 cup of rubbing alcohol Squeeze as much air as possible out of the bag before zipping and sealing.  Place the bag in the freezer for at least two hours before removing for use 36 Home made

37. Super Cooling in Ice/Cold packs If water from the pack accumulates between the pack and the skin, absorbs salts from the skin and becomes very cold. Salt works to depress the freezing point of water so the water can become colder than 0 Celsius before it turns to ice. This can lead to ice burns by super-cooling of the skin. 37

38. Application of Ice/Cold packs To prevent supercooling; Vegetable or nut oil is applied over the skin before ice pack application. The layer of oil causes the water produced by the melted ice to run quickly and easily off the skin and into a gutter, so preventing super-cooling. This is to try and prevent a supercooling/ice burn. 38

39. Gutter Preparation 39 A gutter made of polythene sheet is folded and placed on the bed, below the part to be treated. A folded towel is placed underneath its edges in order to channel the water produced from the melting ice into a container at the side of the bed.

40. Ice-cube/Ice Popsicle A large block of ice, such as water frozen in a yoghurt pot. The exposed end of the ice block is massaged in a circular manner over the treatment area, applying only minimal pressure to the part. The maximum time of application is up to 10 minutes. useful in the treatment of bed-sores, A marked increase in circulation should accelerate repair. 40

41. Ice Immersion The part to be treated such as hands, feet and elbows is immersed in an ice solution. The solution is made up of 50% ice and 50% water placed in a suitable container. Allows circumferential cooling. A single 10-minute session or a series of shorter immersions until a cumulative total of 10 minutes has been reached 41

42. Excitatory cold The marked sensory stimulus of ice on the skin may be used to facilitate contraction of inhibited muscles. ascertain the myotome of the inhibited muscle and then to find the area of skin which has corresponding dermatome. the ice is stroked quickly three times over the dermatome and the skin is then dried. The sensory stimulus passes via the peripheral nerve and raising the level of excitation around the anterior horn cell at the spinal cord. 42

43. Controlled compression units Combines the benefits of cold with the advantages of pneumatic compression. Uses sleeves with circulating cold water, attached to an intermittent pump unit. Edematous extremities are placed inside the sleeves. Temperatures used are 7 C and pressures up to 60 mmHg 43

44. Vapocoolant sprays Volatile liquids such as Fluori -methane spray are commonly used Used for spray-and-stretch techniques to treat myofascial pain and for local anaesthesia. Produce an abrupt temperature change over a small surface area Precautions: risk for skin site irritation and local cutaneous freezing 44

45. Duration Localized cold therapy should never be applied longer than 30 minutes, and the skin integrity should be monitored during treatment. Whole body cryotherapy should not exceed five minutes with typical treatment sessions of 2 to 3 minutes. Whole body cryotherapy causes Decreased heart rate, Increased blood pressure, and Lowered respiration. 45

46. How long should you apply ice? 46 https://teambehindtheteam.in/cryotherapy-in-sports/ Bleakey & Hopkins

47. References Cameron MH. Physical Agents in Rehabilitation: An Evidence-Based Approach to Practice. In: 5th ed. St. Louis, Missouri: Elsevier, Inc; 2018. p. 415–547. Youssef A, Verachtert A, De Bruyne G, Aerts J-M. Reverse Engineering of Thermoregulatory Cold-Induced Vasoconstriction/Vasodilation during Localized Cooling. Applied Sciences. 2019 Aug 16;9(16):3372. doi:10.3390/app9163372 Jagmohan Singh. Textbook of electrotheraphy . New Delhi: Jaypee Brothers Medical Publishers; 2012. Use of Cold Therapy in Physiotherapy [Internet]. Samarpan Physiotherapy Clinic Ahmedabad. 2020 [cited 2021 Mar 17]. Available from: https://tinyurl.com/37pbpp23 ‌ Why Does Adding Salt to Water Make it Colder? [Internet]. Sciencing . 2018 [cited 2021 Mar 24]. Available from: https://sciencing.com/adding-salt-water-make-colder-5459114.html Mitra PK. Handbook of Practical Electrotherapy. 1st Ed. Jaypee Brothers Medical Publishers (P) Ltd, New Delhi. 2006. 119-129 Cryotherapy in Sports - Team Behind The Team [Internet]. 2019 [cited 2021 Mar 24]. Available from: https://teambehindtheteam.in/cryotherapy-in-sports/