Victoria M. Steelman, PhD, RN, CNOR, FAAN

April 28, 2017

APIC Conference

Chicago, IL

Myths about Perioperative Hypothermia

Myths

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Objectives� Identify common myths about perioperative hypothermia;

� Describe the pathophysiology of perioperative hypothermia

� Identify evidence-based practices for prevention of perioperative hypothermia

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Disclosures� 3M

� Dr. Steelman is a paid consultant

� VitaHEAT� The University of Iowa has received grant funding

� Dr. Steelman is a paid consultant

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Perioperative Hypothermia

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� Compelling evidence identifies what interventions are needed to prevent perioperative hypothermia.

� This evidence is inadequately infused into clinical practice.

� Myths or erroneous beliefs are common.

� Debunking these myths is necessary to provide excellent patient care and improve patient outcomes.

� This is the next frontier for perioperative patient safety.

Myth # 1.

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Perioperative hypothermia is not a significant issue.

Rationale:�I haven’t seen a problem.

�No one has told me there has been a problem.

�We use therapeutic hypothermia for cardiac surgery.

Incidence of Perioperative Hypothermia

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� 50-80% of all surgical patients

Frank SM, ShirY, Raja SN, Fleisher LA, Beattie C. Core hypothermia and skin-surface temperature gradients: epidural versus general anesthesiaGalvão CM, Marck PB, Sawada NO, Clark AM. A systematic review of the effectiveness of cutaneous warming systems to prevent hypothermia.J Clin Nurs. 2009;18(5):627-636.Dhar P. Managing perioperative hypothermia. J Anesth. 2000;14(2):91-97.Fisher, RL. Perioperative hypothermia; Incidence and prevention. Thesis, Columbia University, 1990.

Hypothermia Normothermia

� Vasoconstriction

� Decreased oxygen in tissue

� Decreased neutrophil activity

� Decreased deposition of collagen

� Decreased immune function

.

Surgical Site Infection

Kurz A, Sessler DI, Lenhardt R. N Engl J Med. 1996;334:1209-1215.

6%

19%

0%

5%

10%

15%

20%

Normthermic Hypothermic

Percent of Patients with Surgical site Infection

©2015 The University of Iowa. Used with permission.8

� Thermoregulatory responses effect cold stress on the cardiovascular system

� Increases the risk of morbid cardiac event and ventricular tachycardia

Myocardial Events

Frank SM, Fleisher LA, Breslow MJ, et al. JAMA. 1997;277:1127-1134.

1.4%2.4%

6.3%

7.9%

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

CardiacEvents

V Tach

Normothermic Hypothermic

Percent of Patients with Morbid Cardiac Events

©2015 The University of Iowa. Used with permission.9

� Platelet function & coagulation cascade are impaired

� Increased blood loss

Blood Loss

1. Winkler M, Akca O, Birkenberg B, et al. Anesth Analg. 2000;91:978-984. 2. Schmied H, Kurz A, Sessler DI, Kozek S, Reiter A. Lancet. 1996;347:289-292;

Average Blood Loss (mL)

488

1700

618

2200

0

500

1000

1500

2000

2500

Study 1 Study 2

Normothermic Hypothermic

©2015 The University of Iowa. Used with permission.10

Drug Metabolism

� Hypothermia reduces drug metabolism

� More than doubles the duration of action of neuromuscular blocking agents

� Increased length of stay in postanesthesia recovery

Lenhardt R, Marker E, Goll V, et al. Anesthesiology. 1997;87:1318-1323.

53

94

0102030405060708090

100

Normthermic Hypothermic

Length of Postanesthesia Stay (min)

©2015 The University of Iowa. Used with permission.11

Myth # 2.

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Increasing the ambient temperature of the operating room will prevent perioperative hypothermia.

Rationale:�It’s just logical. At home, if we get cold, we

turn up the room temperature.

How does Hypothermia Happen?

General Anesthesia� Removes ability to employ behavioral responses� Widens the interthreshold range 20-fold (0.2oC to 4oC)� Diminishes the hypothalmic response

Regional Anesthesia� Response is similar to general anesthesia� Prevents normal activation of regional responses (sweating, shivering)� Impairs central control of thermoregulation

� Incorrectly judges skin temperature� Patients often feel warm when they are not

� Interthreshold range is increased by 0.6oC

13 Sessler DI. Perioperative thermoregulation and heat balance. Lancet. 2016;387(10038):2655-2664.

Heat Loss� Heat is lost into the cool operating room environment

� Large areas of skin often exposed during prepping and draping

� Internal organs often exposed during surgery

� Cool intravenous or irrigation fluids increase heat loss

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Redistribution Hypothermia

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� Most patients undergoing surgery experience hypothermia unless effective prevention is used.

� Redistribution of heat from core to periphery occurs upon induction of general anesthesia/administration of a spinal anesthesia.

� Occurs in patients undergoing surgery >30 minutes duration.

� Increasing the room temperature in the OR

Ineffective Prevention

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Normal Core Temperature

RoomTemperature

Gradient

98.6oF 70oF 28.6oF

98.6oF 75oF 23.6oF

98.6oF 80oF 18.6oF

98.6oF 85oF 13.6oF

Active Warming Is Needed� Active warming is required to prevent perioperative

hypothermia. Peripheral tissues are heated, decreasing the temperature gradient between the core and periphery.

� Types of Active Warming:� Forced-air warming� Radiant warming� Circulating water garment � Energy transfer pads� Carbon fiber resistive technology� Silver/carbon ink resistive technology

� Warmed IV fluids when >1 liter administered� Adjunct; alone does not prevent hypothermia

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Myth # 3.

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Turning on the forced air warming after anesthesia start is effective prevention.

Rationale:�I need to turn on the compression stockings

before anesthesia starts, and I don’t have time to do both.

�Documentation does not indicate when I turned it on.

Preoperative Warming

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� Active warming is more effective when patients are warmed 30 minutes before surgery.1-4

� AORN Guideline5

� ASPAN Guideline6

1. Andrzejowski J, et al. Br. J. Anaesth. 2008;101(5):627-631.2. Horn EP, et al. Anesth. Analg. 2002;94(2):409-414.4. Vanni SM, et al. J Clin Anesth. 2003;15(2):119-125.4. Horn EP, et al. Eur. J. Anaesthesiol. 2016; 33:334-340.5. Guideline for prevention of unplanned patient hypothermia. AORN, 2017.6. Hooper VD, et al. Journal of Perianesthesia Nursing, 2010;25(6):346-365.

Myth # 4.

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Cotton blankets are adequate for preoperative warming.

Rationale:�Blankets feel good. Patients like them.

�Our documentation system includes this in the menu of interventions for prevention of hypothermia.

�It is less expensive than forced air warming.

� Passive warming retains heat only� Cotton blankets

� Reduce heat loss by only 33% in non-anesthetized persons1

� Heated cotton blankets� Effect lasts 10 minutes1

� In an RCT, resulted in core temperature of 35.5oC2

� Reflective blankets3

Ineffective Prevention

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1. Sessler DI, Schroeder M. Anesth. Analg. 1993;77(1):73-77.2. Fossum S, Hays J, Henson MM. Journal of Perianesthesia Nursing. 2001;16(3):187-194.3. Ng et al. Anesth. Analg. 2003;96(1):171-176.

Cost of Using Warmed Cotton Blankets

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Supply/Labor Cost per Patient

Laundering blankets $10.80Labor: Nursing assistant stocking blankets (1.5 minutes) $ 0.30

Labor: RN applying cotton blankets (2 minutes/blanket) $ 6.60

Total cost supplies and labor $17.70

$17.70 per patient for an ineffective method of prevention of hypothermia.

Myth # 5.

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Warming intraperitoneal gases during laparoscopy is an effective intervention for preventing hypothermia. Rationale:� It is logical. �Most of our patients are laparoscopic and this is

an easy intervention. �Surgeon X wants this.� It prevents lens fogging.

Heated CO2 is Ineffective

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� 16 eligible studies for meta-analysis

� Heated gases with or without humidification

� Results- No effect on:� Core temperature

� Pain

� Morphine consumption

� LOS

� LOS in PACU

� Lens fogging

Heated CO2 with or without humidification for minimally invasive abdominal surgery.Birch DW, Manouchehri N, Shi X, Hadi G, Karmali S.Cochrane Database Syst Rev. 2011 Jan 19;(1):CD007821.

Ineffective and costly.

Potential Cost Avoidance:

CO(2) Insufflation Tubing

# Laparoscopies Cost of tubing

Weekly Cost

Annual Cost Savings

50/wk $37 $1,850 $96,200

100/wk $37 $3,700 $192,400

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Myth # 6.

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Compliance with the quality performance indicator means we are providing excellent patient care.

Rationale:�That is why they make quality performance

indicators.

�It is evidence-based.

�Administration is happy with our results.

Quality Performance Measure

Perioperative Temperature Management

� Written by the AMA Physician Consortium for Process Improvement (PCPI) Anesthesia and Critical Care Workgroup

� Endorsed by the National Quality Forum (NQF)23

� Used by The Joint Commission, Centers for Medicare and Medicaid Services

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Quality Performance Measure� Process measure

� No evaluation of fidelity

� Compliance can be achieved without appropriately using active warming or achieving normothermia

� Inspires checklist mentality and complacency

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The Gap

5.8% of patients for whom the quality performance measure was met were hypothermic upon admission PACU.

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The Gap between Compliance with the Quality Performance Measure "Perioperative Temperature Management" and Normothermia.Steelman VM, Perkhounkova YS, Lemke JH.J Healthc Qual. 2015 Nov-Dec;37(6):333-41. doi: 10.1111/jhq.12063.

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Data Are Needed

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� Preoperative warming adherence� Preop area

� Later: ED, inpatient units

� Intraoperative warming adherence� % use of active warming technology

� % started before induction of anesthesia

� Percent patients who are hypothermic� =/> 30 minutes surgery duration

� Stratified by surgical service

� Later: Stratified by problem-prone areas

Summary� Myths about perioperative hypothermia are a barrier to

achieving full adoption of evidence-based practices and optimal patient outcomes.

� Understanding the pathophysiology of perioperative hypothermia is essential.

� Active warming preoperatively and intraoperatively is essential.

� Education is never enough.� Measure patient outcomes, not quality performance

measures.

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Your Questions

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References

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� Andrzejowski J, Hoyle J, Eapen G, Turnbull D. Effect of prewarming on post-induction core temperature and the incidence of inadvertent perioperative hypothermia in patients undergoing general anaesthesia. Br. J. Anaesth. 2008;101(5):627-631.

� Andrzejowski JC, Turnbull D, Nandakumar A, Gowthaman S, Eapen G. A randomised single blinded study of the administration of pre-warmed fluid vs active fluid warming on the incidence of peri-operative hypothermia in short surgical procedures. Anaesthesia. 2010;65(9):942-945.

� Birch DW, Manouchehri N, Shi X, Hadi G, Karmali S. Heated CO(2) with or without humidification for minimally invasive abdominal surgery. Cochrane database of systematic reviews (Online). 2011;(1)(1):CD007821.

� Dhar P. Managing perioperative hypothermia. J. Anesth. 2000;14(2):91-97.

� Fossum S, Hays J, Henson MM. A comparison study on the effects of prewarming patients in the outpatient surgery setting. J. Perianesth. Nurs. 2001;16(3):187-194.

� Frank SM, Fleisher LA, Breslow MJ, et al. Perioperative maintenance of normothermia reduces the incidence of morbid cardiac events. A randomized clinical trial. JAMA. 1997;277(14):1127-1134.

� Frank SM, ShirY, Raja SN, Fleisher LA, Beattie C. Core hypothermia and skin-surface temperature gradients. Epidural versus general anesthesia and the effects of age. Anesthesiology. 1994;80(3):502-508.

� Galvao CM, Marck PB, Sawada NO, Clark AM. A systematic review of the effectiveness of cutaneous warming systems to prevent hypothermia. J. Clin. Nurs. 2009;18(5):627-636.

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� Guideline for prevention of unplanned patient hypothermia. In: AORN, ed. 2017 Guidelines for Perioperative Practice.Vol 2017. Denver, CO: Association of periOperative Registered Nurses; 2017:567-590.

� Hooper VD, Chard R, Clifford T, et al. ASPAN's evidence-based clinical practice guideline for the promotion of perioperative normothermia: second edition. J. Perianesth. Nurs. 2010;25(6):346-365.

� Horn EP, Bein B, Broch O, et al. Warming before and after epidural block before general anaesthesia for major abdominal surgery prevents perioperative hypothermia: A randomised controlled trial. Eur. J. Anaesthesiol. 2016;33:334-340.

� Horn EP, Schroeder F, Gottschalk A, et al. Active warming during cesarean delivery. Anesth. Analg. 2002;94(2):409-414.

� Kurz A, Sessler DI, Christensen R, Clough D, Plattner O, Xiong J. Thermoregulatory vasoconstriction and perianesthetic heat transfer. Acta anaesthesiologica Scandinavica.Supplementum. 1996;109:30-33.

� Lenhardt R, Marker E, Goll V, et al. Mild intraoperative hypothermia prolongs postanesthetic recovery. Anesthesiology. 1997;87(6):1318-1323.

� Ng SF, Oo CS, Loh KH, Lim PY, Chan YH, Ong BC. A comparative study of three warming interventions to determine the most effective in maintaining perioperative normothermia. Anesth. Analg. 2003;96(1):171-176.

� Sessler DI. Perioperative thermoregulation and heat balance. Lancet. 2016;387(10038):2655-2664.

� Sessler DI, Schroeder M. Heat loss in humans covered with cotton hospital blankets. Anesth. Analg. 1993;77(1):73-77.

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� Shaw CS, Steelman VM, DeBerg J, Schweizer M. Title:Effectiveness of active and passive warming for the prevention of inadvertent hypothermia in patients receiving neuraxial anesthesia: A systematic review and meta-analysis of randomized controlled trials. J Clin Anesth. 2017.

� Steelman VM, Perkhounkova YS, Lemke JH. The Gap between Compliance with the Quality Performance Measure "Perioperative Temperature Management" and Normothermia. J HealthcQual. 2015;37(6):333-341.

� Vanni SM, Braz JR, Modolo NS, Amorim RB, Rodrigues GR, Jr. Preoperative combined with intraoperative skin-surface warming avoids hypothermia caused by general anesthesia and surgery. J Clin Anesth. 2003;15(2):119-125.