Discuss the legal and ethical issues of the study.  Include the use of human subjects and their protection.

Identify the research problem.

Identify the research purpose.

Summarize the review of literature.

Identify the nursing framework.

Identify the research questions and hypotheses.

Identify the variables.

Identify and discuss the appropriateness of the design.

Discuss the validity of the research.

Discuss the efficacy of the study.  Did it resolve the question?

Discuss the legal and ethical issues of the study.  Include the use of human subjects and their protection.

Describe any cultural aspects of the study.

Describe the sample.

Describe the procedures.

Summarize the results.

Describe how the results of the research may impact future nursing practice.

Nurses’ Knowledge of Inadvertent Hypothermia

JOSEPHINE HEGARTY, PHD, MSC, RNT, BSC, RGN; ELLA WALSH, MSC, BSC, DIP NURSING, RGN; AILEEN BURTON, MSC, BSC, RGN; SHEILA MURPHY, RGN, RM, HDIP NURSING MANAGEMENT;

FIONUALA O’GORMAN, MSC ED, BSC, ENB 176, RGM, RGN; GRÁINNE MCPOLIN, HDIP ANAESTHETIC NURSING, BA, RGN

In the perioperative environment,between 60% and 90% of patientsinadvertently become hypothermic.1 Hypothermia not only has significant negative consequences for the health of the patient, but also incurs economic expense for society in terms of increased hospital stay and additional proce- dures and diagnostic tests. Thus, it is paramount that all perioperative nurs- es possess an in-depth understanding of inadvertent hypothermia, including risk factors, complications, and meth- ods of prevention and treatment. It is only through use of this knowledge that nurses can effectively fulfill their roles in the assessment, treatment, and prevention of hypothermia.

A comprehensive literature review revealed a paucity of research pertaining to nurses’ knowledge of hypothermia. We designed this study to gain an under- standing of perioperative nurses’ knowl- edge in relation to accidental hypother- mia in the perioperative setting.

BACKGROUND Accidental hypothermia in perioper-

ative patients is associated with poor patient outcomes. At the very least, it subjects patients to an unpleasant sen- sation of cold.2 It also has much more significant negative consequences, which have been detailed in the litera- ture (Table 1). The magnitude of these adverse consequences should alert all nurses to their important role in reduc- ing and alleviating the occurrence of this problem.

DEFINING NORMOTHERMIA AND HYPOTHERMIA. The control of body temperature within a defined range is crucial in the mainte- nance of a stable environment in the human body, thus enabling optimal

function.2 The literature, however, pres- ents varying definitions of normother- mia (ie, normal body temperature). For example, the American Society of Peri- Anesthesia Nurses (ASPAN) clinical guideline for the prevention of un – planned perioperative hypothermia defines normothermia as “a core tem- perature range from 36° C to 38° C (96.8° F to 100.4° F).”3 Meanwhile, the National Institute for Health and Clini- cal Excellence (NICE) 2008 guideline for the management of inadvertent perioperative hypothermia in adults defined the expected normal tempera- ture range of adult patients as between 36.5° C and 37.5° C (97.7° F to 99.5° F).4

Kiekkas et al1 concur with this defini- tion of normothermia.

Just as the literature presents varying definitions of normothermia, it also pres- ents varying definitions of hypothermia.

© AORN, Inc, 2009 APRIL 2009, VOL 89, NO 4 • AORN JOURNAL • 701

Inadvertent hypothermia can have significant conse- quences in the perioperative setting. Knowing how to recognize and manage inadvertent hypothermia is an important aspect of perioperative nursing.

A quantitative, descriptive study was conducted at an annual perioperative nursing conference to evaluate nurses’ knowledge regarding the prevention of inadver- tent perioperative hypothermia.

Significant variations in responses regarding definitions of hypothermia and normothermia were noted. In addi- tion, nurses identified a plethora of factors that prevent them from maintaining normothermia in their patients. These factors mandate a need for educational interven- tions and the adoption of practice guidelines in the clini- cal area.

Key words: inadvertent hypothermia, normothermia, practice guidelines. AORN J 89 (April 2009) 701-713. © AORN, Inc, 2009.

ABSTRACT

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Kiekkas et al state,

the strict physiological definition of hypo – thermia in humans is a core temperature more than 1 [standard deviation] less than the mean value under resting conditions in a thermoneutral environment.1(p47)

Meanwhile, Kempainen and Brunette define accidental hypothermia as “an unintentional decrease in core temperature to below 35° C (95° F).”5(p192) The NICE guideline defines hypo – thermia as a core temperature of less than 36º C (96.8° F).4 Some consensus is evident in that AORN’s “Recommended practices for the pre- vention of unplanned perioperative hypother- mia” also defines hypothermia as “a core body temperature less than 36° C (96.8° F).”6(p491) Simi-

larly, the ASPAN clinical guideline defines hypothermia as a core temperature of less than 36° C (96.8° F).3 Several authors concur with this definition.7-9

RISK FACTORS. Many risk factors for the devel- opment of hypothermia, including extremes of age, have been identified in the literature. Older adults are particularly prone to the development of the condition.5,6,10-13 This is pri- marily because older persons lose heat more rapidly than younger persons because of decreased fat and muscle mass. In addition, changes in vascular tone in the older adult inhibit vasoconstriction and thus decrease heat production. Furthermore, general anesthesia or major regional anesthesia impairs the ther- moregulatory mechanisms of an older person to a greater extent those of a younger person.6

TABLE 1 Adverse Consequences of Inadvertent Perioperative Hypothermia

• Increased blood loss, thus increasing allogenic transfusion requirements1-5 • Increased incidence of wound infections1,3-8 • Prolonged recovery and postanesthesia care unit stay1-3,5-8 • Postanesthesia shivering6-8 • Myocardial ischemia3,6 • Thermal discomfort2,8 • Cardiac complications2,4,5,7,8 • Impaired medication metabolism3,5,7,8 • Coagulopathy3,5,7-9 • Increased mortality in trauma patients5 • Impaired immune function8 • Deep vein thrombosis8

1. Doufas AG. Consequences of inadvertent hypothermia. Best Pract Res Clin Anaesthesiol. 2003;17(4): 535-549. 2. Torossian A; TEMMP (Thermoregulation in Europe Monitoring and Managing Patient Temperature) Study Group. Survey on intraoperative temperature management in Europe. Eur J Anaesthesiol. 2007; 24(8):668-675. 3. Bitner J, Hilde L, Hall K, Duvendack T. A team approach to the prevention of unplanned postoperative hypothermia. AORN J. 2007;85(5):921-929. 4. Hooper VD. Adoption of the ASPAN clinical guideline for the prevention of unplanned perioperative hypothermia: a data collection tool. J Perianesth Nurs. 2006;21(3):177-185. 5. Recommended practices for the prevention of unplanned perioperative hypothermia. Perioperative Stan- dards and Recommended Practices. Denver, CO: AORN, Inc; 2009:491-504. 6. Kiekkas P, Poulopoulou M, Papahatzi A, Panagiotis S. Effects of hypothermia and shivering on standard PACU monitoring of patients. AANA J. 2005;73(1):47-53. 7. Insler SR, Sessler DI. Perioperative thermoregulation and temperature monitoring. Anesthesiol Clin. 2006;24(4):823-837. 8. Leslie K, Sessler DI. Perioperative hypothermia in the high-risk surgical patient. Best Pract Res Clin Anaesthesiol. 2003;17(4):485-498. 9. Wheeler D. Temperature regulation. Surgery. 2006;24(12):446-451.

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Research literature has identified that infants and neonates are at an increased risk of devel- oping hypothermia6,10,11 because of their in – creased ratio of body surface area to body mass. Infants also are unable to shiver to gen- erate heat in response to hypothermia.5

Certain health conditions also increase patients’ risk of becoming hypothermic. These include hypothyroidism, other endocrine dis- orders, cardiac disorders, arthritis, paralysis, extensive body burns, cachexia, trauma, hypo- glycemia, intoxication, myocardial infarction, and head or spinal cord injuries.5,11,13

The surgical experience also increases pa – tients’ risk of developing hypothermia. This is because the body and internal organs are exposed to lower environmental temperatures, wet preparation solutions are used on the skin’s surface, and the body is unable to shiver and vasoconstrict when the patient is anesthetized during surgery.1,6,14 It is important to note that in certain surgeries (eg, neurosurgeries, cardiac surgeries), hypothermia is warranted and is thus induced. For the purposes of this article, howev- er, we focused solely on inadvertent hypother- mia in the perioperative setting.

LITERATURE REVIEW To date, the area of nurses’ knowledge in

relation to hypothermia remains underinvesti- gated. In fact, we located only two studies— one in a perioperative environment and one in a general hospital setting—conducted between 2003 to 2008.15,16

IRELAND ET AL. In a study using a survey design, Ireland et al15 investigated nurse and medical staff member knowledge and under- standing of issues surrounding accidental or exposure hypothermia in trauma patients. A secondary aim of their study was to increase staff members’ awareness about evaluating and documenting temperature.

A 14-item survey tool was administered to all medical (n = 41) and nursing (n = 99) staff members employed in the Emergency and Trauma Centre of the Alfred Hospital Aus- tralia, Melbourne, Victoria. Ninety-six surveys were returned, yielding a response rate of 69%. Results revealed that nursing and medical staff members were unsure of how to define hypo –

thermia, as evidenced by the array of responses with regard to the cut-off temperature for hypo – thermia. This uncertainty may be partly a result of discrepancies in the literature regarding defi- nitions of hypothermia.

Additionally, results revealed that nurses and physicians were unfamiliar with simple means of preventing heat loss or of rewarming patients. Simple rewarming techniques that are readily available in the Emergency and Trauma Centre were infrequently listed. These included mini- mization of exposure (n = 8), removal of wet clothing/bandages (n = 3), and provision of dry linen (n = 1). Contrarily, rewarming strategies rarely used in the Emergency and Trauma Cen- tre—including warm cavity lavage, cardiopul- monary bypass, and heat packs—were frequent- ly identified. This perhaps suggests an aware- ness of sophisticated rewarming strategies from the literature but a failure to implement simple strategies in practice. Results revealed that all respondents could list at least one rewarming strategy, with 95 respondents able to list three rewarming strategies.

When asked to list common complications associated with hypothermia, the participants described complications in detail. The complica- tions of metabolic acidosis and coagulopathy were infrequently reported, even though these

Conditions that increase patients’ risk

of becoming hypothermic include

hypothyroidism, other endocrine

disorders, cardiac disorders, arthritis,

paralysis, extensive body burns,

cachexia, trauma, hypoglycemia,

intoxication, myocardial infarction,

and head or spinal cord injuries.

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are well described in the literature.14,17-19 When asked to outline factors that prevented or limited them from obtaining a patient’s temperature, respondents identified the following factors: • anatomical injury (n = 26), • access to the patient (n = 10), • access to the necessary equipment (n = 8), and • patient acuity (n = 3).

Despite these obstacles, it is essential that temperature be monitored. Overall, the results of this study emphasize the need for educating nurses and physicians about hypothermia. The authors recommended the development of a best-practice guideline to assist staff members in the unit in the monitoring and overall manage- ment of hypothermia, which could thus lead to an improvement in patient outcomes.

EVANS AND KENKRE. In a quantitative, descrip- tive study conducted in 2006, Evans and Kenkre16 examined the current practice of tem- perature management in a medium-sized acute general hospital in South Wales, United Kingdom. Using a self-administered survey tool, researchers collected baseline data on pat- terns of temperature measurement with re – spect to health care occupational group, fre- quency of temperature measurement, and equipment used. Secondly, the researchers sought information on the knowledge of health care practitioners with regard to infra – red tympanic thermometry (IRTT). Finally, information was collected on any training received in the use of IRTT. A cross-sectional sample of staff members was recruited from within the hospital. Completed questionnaires were returned by 139 staff members, including • 51 (37.0%) who were nursing auxiliary

grade (ie, nursing assistants); • 48 (34.5%) who were staff nurse grade; and • 29 (20.9%) who were sister grade (ie, clinical

nurse manager). Data were missing for 11 (7.9%).

Evans and Kenkre16 found that temperature measurement is frequently undertaken by all grades of nursing staff members. The researchers also revealed, however, that the group most involved in temperature measurement were the nursing auxiliary grade staff members who had the fewest years of clinical experience. In fact, a one-way analysis of variance (ANOVA) con- firmed a relationship between reduced frequen- cy of checking patient temperatures and in – creased years of experience in the clinical role.

The remainder of this study focused on the frequency of use of various temperature meas- uring equipment and staff member knowledge regarding the technological workings of this equipment. Although, undoubtedly, the fre- quency of use of temperature monitoring equip- ment and staff member knowledge in relation to the technological workings of this equipment is important, our study is concerned with nurses’ knowledge in relation to hypothermia and not temperature monitoring equipment. Therefore, it is beyond the scope of this article to examine these results16 in detail.

PERIOPERATIVE IMPLICATIONS The lack of research examining nurses’

knowledge of hypothermia provides a com- pelling impetus for further study in this area. Given the detrimental consequences associated with hypo thermia, we were eager to determine nurses’ knowledge base on this topic. After base- line nursing knowledge levels have been estab- lished, interventions required to augment and improve nurses’ knowledge can be designed.

DESIGN, SETTING, AND SAMPLE We employed a quantitative, descriptive

design. After receipt of protocol approval from the relevant clinical research ethics committee, we recruited a volunteer convenience sample of all delegates in attendance at the National Annual Conference of the Irish Anaesthetic and Recovery Nurses Association that took place in the Republic of Ireland, Waterford City, October

704 • AORN JOURNAL

The lack of research examining

nurses’ knowledge of hypothermia

provides a compelling impetus for

further study in this area.

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AORN JOURNAL • 707

13, 2007. Participants were informed in an informational leaflet that their participation was voluntary and that all information provided by them would be kept confidential. The leaflet also detailed the aims and objectives of the study. There was no identifying information in any of the questionnaires, thus ensuring partici- pant anonymity. All completed questionnaires were placed in a sealed box and we collected them at the close of the conference. Completion of the questionnaire implied consent. Of 198 del- egates in attendance, 130 completed question- naires, thus yielding a response rate of 66%.

INSTRUMENT The survey package consisted of two survey

tools both adapted with permission from the primary authors of each questionnaire15,20 to suit nurses working in the perioperative environ- ment. This adaptation was based on a review of the literature and the researchers’ knowledge and clinical expertise.

The survey package included two demo- graphic questions, nine questions designed to assess nurses’ knowledge,15 and a 23-item Likert scale based on risk factors for the development of intraoperative hypothermia.20 The nine ques- tions asked participants to define hypothermia and list • factors that can lead to hypothermia in a

patient undergoing anesthesia or surgery, • sources of potential heat loss in an adult, • techniques participants used within their

clinical practices to ensure that patients do not develop hypothermia, and

• complications that are associated with hypothermia for patients who have had sur- gery and anesthesia.

Participants also were asked if patients’ tem- peratures were routinely monitored in their clinical areas and if within their clinical prac- tice there was anything that prevented or lim- ited them in maintaining normothermia in the patients that they cared for.

The final question in the questionnaire was adapted from an article by Macario and Dexter20

in which clinical anesthetists and physician researchers were asked to prioritize a number of risk factors for the development of intraop- erative hypothermia. Participants in our study

were asked to estimate the relevant impor- tance of each risk factor (ie, 23 potential risk factors in total) on a Likert scale of 1 to 10, with 1 implying “not likely to be important” and 10 implying “most likely to be important.” The higher the rating for each question, the greater the perceived importance of that risk factor.

Surveys were completed by two expert peri- operative nurses to assess content validity. The Cronbach’s alpha for this 23-item hypothermia risk factor scale was found to be satisfactory at 0.876. For social sciences scales, the normally acceptable standard for the Cronbach’s alpha is 0.6,21 with levels above 0.7 being desirable.22,23

Although the high Cronbach’s alpha generated for the 23-item scale could be attributed to the large number of items, the item-total correla- tions for each item within the 23-item scale were all > 0.3, thus implying that all items within this scale are measuring the same attribute (ie, risk factors in the development of hypothermia).

DATA ANALYSIS All raw data were coded and entered into

Statistical Package for the Social Sciences, ver- sion 15, 2007. Responses to all closed-ended items were reported individually as frequen- cies and percentages. Meanwhile, responses to all open-ended questions were transcribed in full. Members of the research study team reviewed these responses to identify emergent themes. We then recoded these items with ordinal descriptors.

RESULTS Of the 198 surveys that were handed out, 130

were returned. The demographics of the study population included various work specialties and levels of qualification (Table 2). This repre- sented a response rate of 65.7%.

The majority of respondents had more than four years of experience working in the peri- operative area. Specifically, respondents spent most of their time working in • anesthetic nursing—14.6% (n = 19); • recovery nursing—30% (n = 39); • intraoperative nursing—13.1% (n = 17); or • a combination of two or more of the

above—36.9% (n = 48).

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One respondent identified “other—management” as the area in which he or she spent the most time, and data were missing for six re spondents (4.6%).

In relation to current level of qualification, the majority of respondents (45.4%, n = 59) identified themselves as registered general nurse (RGN). The next largest group were those registered nurses with a postgraduate qualification in perioperative nursing.

When asked to select the cut-off point for hypothermia, respondents were divided: • 38.5% (n = 50) of participants chose 36° C

(96.8º F), • 39.2% (n = 51) chose 35º C (95º F), • 11.5% (n = 15) chose 34º C (91.4º F), and • 8.5% (n = 11) chose 33º C (93.2º F). Data were missing for three respondents (2.3%).

When respondents were questioned about the major sources of potential heat loss in an adult, • 53.1% (n = 69) identified the skin,

• 28.5% (n = 37) identified the head, • 9.2% (n = 12) identified the torso, and • 6.9% identified a combination. Data were missing for three respondents (2.3%).

When asked how best to define normother- mia, the majority of participants identified it as occurring between 36º C and 37º C (96.8º F and 98.6º F) (Table 3).

Regarding whether temperatures are rou- tinely monitored in clinical areas, just under half of participants (n = 55, 42.3%) answered yes. Meanwhile, 43.8% (n = 57) answered “yes as required based on the assessment of the patient,” and 8.5% (n = 11) answered no. Data were missing for seven respondents (5.4%).

Furthermore, 50 participants (38.5%) identi- fied factors that prevent or limit the mainte- nance of normothermia. With regard to these, the most frequently identified factors were tem- perature control of the room (n = 7), surgeon preference (n = 5), overexposure (n = 5), lack of equipment (n = 4), and no air conditioning (n = 3).

Other identified factors included • lack of national tool (n = 2), • positioning (n = 1), • patient condition (n = 1), • type of surgery (n = 1), • no preoperative warming

(n = 1), • lack of staff member expe-

rience (n = 1) and lack of knowledge of staff (n = 1);

• laminar air flow system (n = 1),

• wet bed sheets (n = 1), • use of electric blankets

(n = 1), • fast throughput of patients

(n = 1), and • a combination of factors

(n = 14). A number of open-ended

questions also were included in the questionnaire. The first of these asked participants to identify three common contrib- utory factors to the develop- ment of hypothermia. A total of 74 factors were identified,

TABLE 2 Demographics of Survey Respondents

Perioperative experience Responses Percentage < 12 months 7 5.4 1-3 years 25 19.2 > 4 years 98 75.4

Level of qualification Responses Percentage Registered general nurse

(RGN) 59 45.4 RGN with a BSc 23 17.7 RGN with other postgraduate

course in perioperative nursing 29 22.3 Other 18 13.8 Missing data 1 0.8

TABLE 3 Perception of Normothermia

Temperature range Responses Percentage 36° C to 36.5° C (96.8° F to 97.7° F) 16 12.3 36° C to 37° C (96.8° F to 98.6° F) 43 33.1 36° C to 37.5° C (96.8° F to 99.5° F) 36 27.7 36.5° C to 37.5° C (97.7° F to 99.5° F) 26 20.0 Missing data 9 7.0

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with some participants identifying three factors and others identifying one or two. Table 4 pro- vides a summary of the 10 most commonly identified factors.

Participants also identified a wide range of techniques used in the clinical area to ensure that patients do not develop hypothermia. Each participant was able to identify at least one factor, including • warming devices (eg, forced-air devices)

(n = 92); • use of a fluid or blood warmer (n = 71); • controlling the environmental temperature

(n = 37); • provision of adequate heat with blankets

(n = 36); • regular checking of patients’ temperatures

(n = 24); and • use of foil hats, leggings, or drapes (ie, foil

wrapping used to prevent heat loss) (n = 19). When asked to identify common complica-

tions associated with hypothermia for patients who have had surgery or anesthesia, each par- ticipant could identify at least two complica- tions. Complications that participants listed included • delayed recovery (n = 45), • postoperative shivering (n = 31), • hypotension (n = 27), • increased postoperative pain (n = 26), and • delayed wound healing (n = 20).

Finally, participants were asked to rate fac- tors in the development of hypothermia on a scale of 1 to 10 (Table 5). Major surgery with a large uncovered area was rated as extremely important by many of the participants. Also, being a neonate of younger than one month was considered an extremely important factor in the development of hypothermia.

DISCUSSION The prevention and management of hypo –

thermia centers on the correct assessment of each individual’s risk for hypothermia, use of preventative strategies, monitoring of patients’ temperatures routinely during the periopera- tive period, and employment of appropriate rewarming strategies. Because nurses are pri- marily responsible for these aspects of care during the perioperative period, it follows that

nurses’ knowledge surrounding the concept of hypothermia is central to its successful preven- tion and management.

The nurses who took part in this study were highly experienced, with the majority having more than four years of perioperative experi- ence. In addition, many of these nurses had post- registration qualifications. Because the respon- dents were experienced and well-educated, we anticipated that these nurses would be quite knowledgeable about hypo thermia, because thermoregulation is a fundamental aspect of nursing practice. We found, however, that nurses were unsure of the correct definitions of hypothermia and normothermia. These con- flicting perceived definitions may be a result of the lack of clarity in the literature as to a stan- dard definition of hypothermia. This highlights the need for standardized guidelines—such as those developed by the National Institute for Health and Clinical Evidence,4 AORN,6 and ASPAN3—to be used in practice. The majority of participants defined normothermia as 36º C and 37º C (96.8º F and 98.6º F), which is not concurrent with either the NICE guideline pro- tocol4 or the ASPAN clinical guidelines3 for the prevention of unplanned hypothermia. This uncertainty highlights the need for the adop- tion of standardized guidelines to aid nurses in their clinical practice. It also highlights the need for the development of continuing educa- tional programs to keep practitioners up to

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TABLE 4 Top 10 Perceived Factors for Hypothermia Development

Factor identified Responses Theatre environment

temperature 58 Body exposure 40 Length of surgery 35 Fluid and blood loss 29 Anesthesia-induced

bradycardia 21 Patient age 19 Cold infusion fluids 14 Prolonged exposure 9 Shock 9 Fasting 8

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date with the current best evidence. The evidential lack of uniformity in the lit-

erature with regard to some definitions and preventative measures may have contributed to some of the varying responses within this survey. The tools used in this study allowed us to assess nurses’ knowledge in relation to hypo – thermia from both a quantitative and a qualita- tive perspective, thus increasing the depth of the data ascertained. Overall, staff members in this survey displayed extensive knowledge in the area of hypothermia prevention.

CONTRIBUTING FACTORS. When participants were asked in an open-ended question to list three common factors that contribute to the develop- ment of hypo thermia, the most frequently iden- tified factor was OR environment exposure. When asked to rate certain factors in the devel- opment of hypothermia, a similar factor, OR temperature < 18° C (64.4° F), was also consid- ered to be extreme ly important by more than half of the respondents (53.8%, n = 70). Addi- tionally, body exposure was identified as a

common contributory factor to the development of hypo – thermia in re sponses to the open-ended question (n = 40). A similar factor, major surgery with a large uncovered area, was rated by 93.8% of partici- pants (n = 122) as extremely important. Blood loss was identified as a common con- tributory factor in responses to the open-ended question. This also was rated as an extremely important factor by 73.1% (n = 95) of participants. These concurring answers indicate that participants had accurate knowledge of factors that contribute to the develop- ment of hypothermia.

There were a number of factors identified as extremely important in the 23-item scale relating to risk of develop- ment of hypothermia; howev- er, participants did not identi- fy many of these potential risk

factors in the open-ended question, including neonate younger than one month old. Partici- pants identified the patient’s age as an impor- tant factor, which to a certain degree accounts for this. In addition, a patient with third-degree burns was rated as ex tremely important by 119 participants (91.5%). This did not feature in responses to the open-ended question despite the fact that third-degree burns are a major con- tributory factor.5,11,13

Irrigation fluid below body temperature also was rated as an extremely important factor by 83.8% of participants (n = 109). Cold infusion fluid was cited only 14 times in re sponses to the open-ended question, however. The reality is that cold infusion fluids are a major risk factor in the development of hypothermia.17

Moreover, despite the fact that general anes- thesia is a major risk factor in the development of hypothermia because of “the loss of behavioral response to cold and impairment of thermoregu- latory heat preserving mechanisms,”4(p4) fewer than half of the respondents (n = 60, 46.2%) rated

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TABLE 5

Question: At what point on a scale of 1 to 10 would you rate the following in the development of hypothermia, with 10 being the highest risk? Factor Mean score Major surgery with a large uncovered area 9.9 Neonate < 1 month 9.8 Patient with 3rd degree burns 9.6 Major surgery 9.5 Pediatric surgery 9.4 Surgery > 2 hours in duration 9.4 Older patient 8.9 Cardiac surgery 8.9 Operating theatre room < 18° C (64.4° F) 8.8 Patient hypothermic before surgery 8.6 More than 30 mL/kg blood loss 8.6 Patient undergoing thoracotomy 8.5 Thin patient 7.9 Level of spinal anesthesia 7.7 Open pelvic/abdominal surgery 7.7 General anesthesia 7.4 OR temperature 18° C to 20° C (64.4° F to 68° F) 6.9 Spinal/epidural anesthesia 6.8 OR temperature 20° C to 22° C (68° F to 71.6° F) 5.2 Use of a tourniquet 5.2 Normal body temperature before surgery 4.9 A small surgical procedure 4.0

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it as a major risk factor. It did not feature at all in responses to the open-ended question.

Overall, it was encouraging to see that par- ticipants were able to identify a wide range of contributing factors in the development of hypothermia. The fact that some important factors (eg, cold irrigation fluids, blood loss) were rated as important by participants in the 23-item Likert scale risk factor listing but were not listed in response to the open-ended ques- tion suggests that although participants had the knowledge, they were unable to recall all fac- tors spontaneously without prompting. This further suggests that preformulated guidelines that would prompt practitioners on the impor- tant factors would be helpful in the clinical area.

PREVENTION. When asked about preventing hypothermia in the clinical area, participants cited a wide range of techniques. The most fre- quently identified technique was the use of warming devices (eg, forced-air warming devices). Use of a forced-air warming device is recommended for all patients undergoing anesthesia in the NICE clinical guideline for inadvertent perioperative hypothermia.4 The ASPAN hypothermia guideline3 recommends that forced-air warming devices be initiated only if the patient is hypothermic, however. The AORN guideline6 recommends that forced- air warming is used to prevent hypothermia in patients undergoing anesthesia and in rewarm- ing patients after cardiopulmonary bypass.

Participants also cited using a fluid/blood warmer (n = 71) as an important technique to prevent hypothermia. The NICE clinical guide- line for inadvertent perioperative hypothermia4

supports this; however, the ASPAN hypother- mia guideline3 states that fluid warming devices should be used if the patient is hypothermic and not as a preventative measure. Meanwhile, the AORN guideline6 recommends that warming IV fluids only be considered where large volumes (ie, > 2L/hour) are being transfused.

Thirdly, participants identified control of environmental temperature as an important preventative measure in the development of hypothermia. Both the NICE clinical guideline4

and the ASPAN guideline3 support this. The NICE guideline4 specifies that the OR suite tem- perature should be at least 21° C (69.8° F), and

the ASPAN hypothermia guideline3 states that the room temperature should be at a minimum of 20° C to 24° C (68° F to 75° F). The AORN guideline also alludes to the importance of OR temperature in particular for infants and neonates.6

NURSING CHALLENGES. Lastly, with regard to factors that prevent nurses from maintaining normother- mia in their patients, participants cited a number of factors. It was surprising to see that in a health service that encourages nurses to be autonomous practitioners, one of the most frequently identi- fied factors was surgeon preference.

The majority of nurses reported frequent monitoring of temperature in the clinical area (n = 55). An additional 43.8% (n = 57) reported that temperature is monitored as required based on the assessment of the patient. Encour- agingly, just nine participants answered no to this question. Given the detrimental conse- quences associated with hypo thermia, neg – lecting to conduct regular monitoring could have catastrophic effects for patients.

LIMITATIONS It is the professional responsibility of all re –

searchers to assess and detect the effect of sam- pling deficiencies, design constraints, and data

AORN JOURNAL • 711

With regard to factors that prevent

nurses from maintaining normothermia

in their patients, it was surprising to

see that in a health service that

encourages nurses to be autonomous

practitioners, one of the most

frequently identified factors was

surgeon preference.

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APRIL 2009, VOL 89, NO 4 Hegarty — Walsh — Burton — Murphy — O’Gorman — McPolin

quality problems.22 The current study, as with all research studies, has a number of limitations.

The sample used in this study was chosen from a group of attendees at a national periop- erative conference. The fact that these people voluntarily attended such a conference may imply that they were especially vigilant with regard to their professional obligations for con- tinuing education. This fact may in turn imply that the group as a whole was quite knowledge- able, perhaps limiting generalization of results to the wider population of perioperative nurses.

Another limitation of this study was its small sample size. Perhaps if this study were carried out with a larger sample, the results would be more representative of the entire population of perioperative nurses.

The cross-sectional design of this study did not allow the opportunity to assess nurses’ knowl- edge over time to gauge whether knowledge lev- els change. Perhaps if a longitudinal design were employed, one could assess nurses’ knowledge, implement educational sessions, and then re – assess the nurses’ knowledge at a later stage.

Finally, this study is descriptive in nature. Although this has served as a useful starting point for investigation of the issue, additional research is required to investigate the issue fur- ther. This may involve conducting a correlation- al study to compare knowledge with practice.

RECOMMENDATIONS FOR CLINICAL PRACTICE, EDUCATION, AND FUTURE RESEARCH

Clinical guidelines for the prevention and management of inadvertent perioperative hypothermia need to be readily available for practitioners and adopted for use in the peri- operative environment. The NICE clinical guidelines, the AORN recommended practices for the prevention of unplanned hypothermia, and the ASPAN clinical guideline for the pre- vention of unplanned perioperative hypother- mia are available. Furthermore, nurse man- agers should be cognizant of the need to organize regular educational sessions about hypothermia for staff members. The detrimen- tal consequences associated with hypothermia cannot be underestimated. Educational ses- sions would allow practitioners to keep up to date with best research evidence and allow for

the exchange of clinical expertise. From a research perspective, there is a lack

of research in the area of nurses’ knowledge regarding hypothermia and, crucially, a com- plete absence of higher-level evidence. Perhaps conducting a randomized, controlled trial to investigate nurses’ knowledge before and after an educational intervention would be useful. In addition, we believe that conducting an observational study to monitor nurses’ activities in relation to hypothermia prevention and management would be most useful.

Acknowledgements: The authors thank Sharyn Ireland, RN, Dip, HSc, BNurs, CritCareCert, ACCN, MEd, clinical nurse specialist, Emergency and Trauma Centre, The Alfred, Melbourne, for her permission to use the staff survey tool that she and her colleagues developed to explore nursing and med- ical knowledge regarding hypothermia management. The authors also thank Alex Macario, MD, MBA, professor of anesthesia and health research and policy program director, Anesthesia Residency Department of Anesthesia, Stanford University, California, for his permission to use the listing of risk factors in the development of intraoperative hypothermia generated from his paper, “What are the Most Important Risk Factors for a Patient’s Developing Intraoperative Hypothermia?” Special thanks to members of the IARNA committee, most especially Eilis Daly, BSc, Dip Nursing, RGN, MSc, clinical nurse manager, Day Procedures Unit, South Infirmary Victoria Uni- versity Hospital, Cork, Ireland; Ann Hogan, HDip (Perioperative Nursing), RGN, MSc, clinical nurse manager, Recovery Unit, Waterford Regional Hospi- tal, Waterford, Ireland; Lorraine O’Rourke, RGN, HDip Perioperative Nursing, clinical nurse manager, South Infirmary University Hospital, Cork, Ireland; Lorraine Murphy, PG Dip, MSc, professional learn- ing facilitator, Nursing and Midwifery Planning Development Unit, Health Services Executive South, Ireland; Breda Needham, RGN, HDip Nursing Stud- ies, clinical nurse manager, Surgical Day Theatres, Mid Western Regional Hospital, Limerick, Ireland; and Brigid Fitzpatrick-Laffan, HDip (Perioperative Nursing), Dip (Health Services Management), RN, RM, clinical nurse manager, Theatre, Mid Western Regional Hospital, Limerick, Ireland. Finally, a spe- cial word of thanks is extended to the nurses who participated in this study.

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REFERENCES 1. Kiekkas P, Poulopoulou M, Papahatzi A, Panagio- tis S. Effects of hypothermia and shivering on stan- dard PACU monitoring of patients. AANA J. 2005; 73(1):47-53. 2. Hegarty J. Perioperative temperature regulation: management of hypothermia. The All-Ireland Journal of Nursing and Midwifery. 2003;2(9)18-19. 3. Clinical guideline for the prevention of unplanned perioperative hypothermia. American Society of Peri- Anesthesia Nurses. http://www.aspan.org/Clinical Practice/ClinicalGuidelines/Hypothermia/tabid/325 5/Default.aspx. Accessed February 3, 2009. 4. Management of inadvertent perioperative hypo – thermia in adults. April 2008. National Institute for Health and Clinical Excellence. http://www.nice .org.uk/Guidance/CG65. Accessed February 3, 2009. 5. Kempainen RR, Brunette DD. The evaluation and management of accidental hypothermia. Respir Care. 2004;49(2):192-205. 6. Recommended practices for the prevention of unplanned perioperative hypothermia. In: Periopera- tive Standards and Recommended Practices. Denver, CO: AORN, Inc; 2009:491-504. 7. Young VL, Watson ME. Prevention of periopera- tive hypothermia in plastic surgery. Aesthet Surg J. 2006;26(5):551-571. 8. Doufas AG. Consequences of inadvertent hypo – ther mia. Best Pract Res Clin Anaesthesiol. 2003;17(4): 535-549. 9. Lenhardt R. Monitoring and thermal management. Best Pract Res Clin Anaesthesiol. 2003;17(4):569-581. 10. Ayres U. Older people and hypothermia: the role of the anaesthetic nurse. Br J Nurs. 2004;13(7):396-403. 11. Day MP. Hypothermia: a hazard for all seasons. Nursing. 2006;36(12 Pt 1):44-47. 12. Evered A. Hypothermia: risk factors and guide- lines for nursing care. Nurs Times. 2003;99(49):40-43. 13. Neno R. Hypothermia: assessment, treatment and prevention. Nurs Stand. 2005;19(20):47-52. 14. Leslie K, Sessler DI. Perioperative hypothermia in the high-risk surgical patient. Best Pract Res Clin Anaesthesiol. 2003;17(4):485-498. 15. Ireland S, Murdoch K, Ormrod P, et al. Nursing and medical staff knowledge regarding the moni- toring and management of accidental or exposure hypothermia in adult major trauma patients. Int J Nurs Pract. 2006;12(6):308-318. 16. Evans J, Kenkre J. Current practice and knowl- edge of nurses regarding patient temperature meas- urement. J Med Eng Technol. 2006;30(4):218-223. 17. Bitner J, Hilde L, Hall K, Duvendack T. A team approach to the prevention of unplanned postoper- ative hypothermia. AORN J. 2007;85(5):921-929. 18. Insler SR, Sessler DI. Perioperative thermoregu- lation and temperature monitoring. Anesthesiol

Clin. 2006;24(4):823-837. 19. Wheeler D. Temperature regulation. Surgery. 2006;24(12):446-451. 20. Macario A, Dexter F. What are the most impor- tant risk factors for a patient’s intraoperative hypothermia? Anesth Analg. 2002;94(1):215-220. 21. Kline P. The Handbook of Psychological Testing. 2nd ed. London, England: Routledge; 2000. 22. Polit DF, Beck CT. Nursing Research Principles and Methods. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2004. 23. Pallant J. SPSS Survival Manual: A Step By Step Guide to Data Analysis Using SPSS (Version 15). 3rd ed rev. Berkshire, United Kingdom: Open Universi- ty Press (McGrath-Hill Education); 2007.

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Josephine Hegarty, PhD, MSc, RNT, BSc, RGN, is an associate professor at the Catherine McAuley School of Nursing and Midwifery, Brookfield Health Sciences Complex, Universi- ty College Cork, Ireland.

Ella Walsh, MSc, BSc, Dip Nursing, RGN, is a lecturer at Catherine McAuley School of Nurs- ing and Midwifery, Brookfield Health Sciences Complex, University College Cork, Ireland.

Aileen Burton, MSc, BSc, RGN, is a lecturer at Catherine McAuley School of Nursing and Midwifery, Brookfield Health Sciences Com- plex, University College Cork, Ireland.

Sheila Murphy, RGN, RM, HDip Nursing Management, is a clinical nurse manager, the- atre recovery, at Cork University Hospital, Wilton, Cork, Ireland.

Fionuala O’Gorman, MSc Ed, BSc, ENB 176, RGM, RGN, is a perioperative programme facilitator, Cork University Hospital, and immediate past president of the Irish Anaes- thetic and Recovery Nurses Association, Wilton, Cork, Ireland.

Gráinne McPolin, HDip Anaesthetic Nurs- ing, BA, RGN, Clinical Facilitator, Major The- atres, Galway University Hospital, Galway, Ireland.

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

  • Nurses’ Knowledge of Inadvertent Hypothermia
    • BACKGROUND
      • DEFINING NORMOTHERMIA AND HYPOTHERMIA
      • RISK FACTORS
    • LITERATURE REVIEW
      • IRELAND ET AL
      • EVANS AND KENKRE
    • PERIOPERATIVE IMPLICATIONS
    • DESIGN, SETTING, AND SAMPLE
    • INSTRUMENT
    • DATA ANALYSIS
    • RESULTS
    • DISCUSSION
      • CONTRIBUTING FACTORS
      • PREVENTION
      • NURSING CHALLENGES
    • LIMITATIONS
    • RECOMMENDATIONS FOR CLINICAL PRACTICE, EDUCATION, AND FUTURE RESEARCH
    • REFERENCES
 

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