Effects of Salted ice bags on surface and intramuscular cooling and rewarming rates

Effects of Salted ice bags on surface and intramuscular cooling and rewarming ratesPresented by: Eric Hunter and Caitlyn CrowleyLiterature reviewCryotherapy is used among healthcare providers to treat acute injuries by reducing pain and limiting the formation of swelling. 1,2Lowers the metabolic rate decreasing the amount of oxygen needed.

No optimal temperature has been set to effectively limit the negative effects of inflammation.3,4 Colder the tissues the better.. No benefit found below 5C. 45*C no additional benefit was detected 2Literature reviewIce bags have been shown to be the most effective at cooling tissue when compared to other packs (gel, chemical). 5,6, 7They cool intra-muscular temperature the fastest and get the coldest.Skin/intramuscular tissue continue cooling longer after the modality has been removedSkin/intramuscular tissue take longer to re-warm to normal temperature

Wetted Ice bags are the most effective at decreasing skin and intramuscular temperature when compared with normal cubed or crushed ice bags. 3

Continued research has looked at most effective ways to cool tissues.No one has looked at adding salt to an ice bag

TheoryUsing knowledge of basic scienceAdding salt to H2O decreases freezing pointsPilot study has demonstrated ability to decrease water temperature by adding salt

Questions for audienceHave you ever wondered why some people put salt in water before boiling it?What about why they put salt on the roads in the winter time?4Pilot dataControl Condition: 2000 mL wetted ice 0.5 C

Experimental Conditions: 2000 mL ice + uniodized saltAmount of Salt AddedResultant Temperature1/2 cup~ -15o C1/4 cup~ -11o C1/8 cup ~ -8o C1/16 cup (1 Tbsp)~ -5o CWhy important to AT Field Decreased tissue temperature Decrease effects of secondary hypoxic injury

Potentially decreased treatment timesFaster numbing (less cold pain)Better patient compliance if treatment doesnt take as long?

Potentially longer re-warming timeSecondary hypoxic injury is reduced for a longer timeMay result in less time loss from injuryStudy designRepeated-measuresCounterbalancedABC, ACB, BCA, BAC, CAB, CBA

Three treatment groupsWetted cubed ice (A) Current best practiceSalted cubed ice (B)Salted crushed ice (C)

Independent variableTimeGroup Dependent variable Temperature SkinIntramuscular

Participants24 subjectsExclusion Criteria18-26HealthyMale and FemaleNo known vascular disease in lower legNo injury to lower leg in the last month or during the studyNo sensitivity to coldNot allergic to cold/iceNo compromised circulation of the lower leg8 recruitmentFliers Tear offsQR Scan

Announcements in class

Measurement toolsSkinfold calipers Skyndex, Cadwell, Justiss and Co, Inc., Fayetteville, ARSurface thermocouple SST-1, Physitemp Instruments, Inc, Clifton, NJ OR Omega thermocouples26-gauge hypodermic needle microprobePhysitemp MT-26/4, Physitemp Instruments, Inc, Clifton, NJMicroprocessor thermometer Model HH23, Omega Engineering, Inc, Stamfort, CT) conditionsWetted ice bagCramer ice bag2000 mL cubed ice300 mL room temperature waterSalted crushed ice bagCramer ice bag1 Tbsp Morton Unionized Salt2000 mL crushed iceSalted cubed ice bagCramer ice bag1 Tbs Morton Uniodized Salt2000 mL cubed ice

Anticipated ProceduresTraining on insertion at BYU by Dr. David Draper & colleaguesCalf measurements taken to determine location of largest girth where microprobe will be inserted on the posterior lateral portion of the calf.Skinfold measurements will be taken 3 times and then the average will be usedDivide mean measurement by 2 for amount of subcutaneous fatFor intramuscular depth measure a vertical distance of 2 cm plus the mean skinfold Mark the lateral aspect of the lateral head of the gastrocnemius using a fabricated template labeled to the nearest millimeter to ensure proper insertion pointInsertion of microprobe and placement of surface thermocouple on participants by the same two researchers

Anticipated ProceduresInsertion area will be shave and cleaned prior to insertionBaseline period of 20 minutes for intramuscular temperatures to reach plateau (participants lying prone on table for entire process) Ice condition appliedTreatment time of 20 minutes Ice removedRecovery time of 45 minutesSurface thermocouple, treatment template and microprobe will be removedArea will be cleaned and covered with a self-adhesive bandage

** Temperatures will recorded every 30 seconds throughout the study

TimelineSpring semester 2013Training in microprobe insertion techniquesSecure funding

Subject recruitment periodBeginning September 2013

Data collection periodSeptember - November 2013

Data analysis periodNovember 2013

Prepared to defend/prepare manuscript for publication!!Spring 2014Statistical analysisRepeated measure ANOVASkin temperature Baseline, 30-second intervals for 20-minute treatment time, 30-second intervals for 45 minute rewarming periodIntramuscular temperatureBaseline, 30-second intervals for 20-minute treatment time, 30-second intervals for 45 minute rewarming period

Microprocessor thermometer will be video recorded to ensure accurate temperature capture at desired intervalswe are doing each DV separately b/c with only 24 subjects, we do not have the power to do a multivariate analysis

ANOVA in general will compare several groups (and in this case, several time periods) and tell you if there is a difference overall. it will also tell you if there is a significant difference at each time period...all wihle maintaining the familywise (overall) type I error rate at 0.05 (your p-value15Null HypothesesThere will be no difference in surface and intramuscular cooling and rewarming rates between the three treatment conditions.

Research HypothesesBoth salted crushed/cubed will decrease skin temperature more than wetted iceBoth salted crushed/cubed will decrease intramuscular temperature more than wetted iceBoth salted crushed/cubed will have longer skin temperature rewarming times than wetted iceBoth salted crushed/cubed will have longer intramuscular temperature rewarming times than wetted iceSalted cubed ice will decrease skin temperature more than salted crushed ice Salted cubed ice will decrease intramuscular temperature more than salted crushed iceChallenges/limitationsIce bag falling offTemplate on skin

Limited rewarming timeInitial/exploratory studyFundingNATA grant$1,000

University grantMoyes Academic Support & Technology Endowment Committee

Funds used forMicroprobesThermocouplesIce bagsSaltSanitizing and sterilizing materialsAdhesive bandagesSubject incentive

References1. Dolan MG, Thornton RM, Fish DR, Mendel FC. Effects of Cold Water Immersion on Edema Formation After Blunt Injury to the Hind Limbs of Rats. J Athl Train. 1997;32(3):233237.2. Meeusen R, Lievens P. The use of cryotherapy in sports injuries. Sports Med. 1986;3(6):398414.3. Merrick MA, Jutte LS, Smith ME. Cold Modalities With Different Thermodynamic Properties Produce Different Surface and Intramuscular Temperatures. J Athl Train. 2003;38(1):2833.4. Sapega AA, Heppenstall RB, Sokolow DP, et al. The bioenergetics of preservation of limbs before replantation. The rationale for intermediate hypothermia. J Bone Joint Surg Am. 1988;70(10):15001513.5. Dykstra JH, Hill HM, Miller MG, Cheatham CC, Michael TJ, Baker RJ. Comparisons of Cubed Ice, Crushed Ice, and Wetted Ice on Intramuscular and Surface Temperature Changes. J Athl Train. 2009;44(2):136141.6. Kennet J, Hardaker N, Hobbs S, Selfe J. Cooling Efficiency of 4 Common Cryotherapeutic Agents. J Athl Train. 2007;42(3):343348.7. Myrer JW, Draper DO, Durrant E. Contrast Therapy and Intramuscular Temperature in the Human Leg. J Athl Train. 1994;29(4):318322.

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