C6INTRAOPERATIVE WARMING DEVICES

StudyParticipantsInterventions
Baxendale 2007
Trial held in UK
Inclusion: major abdominal or orthopaedic surgery
Age (range):not stated; gender (m/f): not stated
comorbidities: not stated; all patients received IV fluids warmed via a Bair Hugger hose thought surgery. Numbers randomised to each group not stated;
n=80
  1. Bair Hugger (active warming device); duration: after induction for the duration of surgery; 43°C; n=not stated
  2. Inditherm mattress (active warming device); duration: from induction until transfer to recovery unit; 37°C; n=not stated
Bennett 1994
Trial held in UK
Inclusion: Patients undergoing hip arthroplasty;
Exclusion: patients who were grossly obese or malnourished or who had endocrine abnormalities or pyrexia Age (range):71(range 59–88): 74 (range 54–84); 73 (range 63–89): gender (m/f): 30:15; Duration of surgery: 2.0 hours (SD 0.3): 2.5 hours (SD 0.6): 2.3 hours (SD 0.3);
comorbidities: not stated; ambient temperature: 19–21°C; IV at ambient temperature at rate of 6ml/kg/h. Blood warmed to 37°C before infusion. Relative humidity maintained at 40–50%; ambient temperature (recovery)-23–25°C
  1. Metallized plastic garment (thermolite, techstyles (thermal insulation; duration: after induction until end of surgery; n=15
  2. usual care; duration: not stated; n=15
  3. Convective warm air blanket (Bair Hugger); 43°C; n=15
Berti 1997
Trial held in Italy
Inclusion: Patients undergoing total knee or hip arthroplasty. None of the subjects were obese, taking medications, or history of thyroid disease, dyautonomia or Raynaud’s syndrome; Exclusion criteria not stated.
Age (range):68 years; gender (m/f): not stated
comorbidities: not stated; room temperature: 21–23°C; IV fluid and skin disinfectants:room temperature; laminar air flow humidity maintained 40–45%
  1. FAW (Bair Hugger, Augustine Medical + low flow anaesthesia (active warming device; duration: not stated; 38°C; n=10
  2. Low flow anaesthesia (heat retentive therapy); duration: not stated; n/r; n=10
  3. Insulated blanket (thermadrape) + low drape anaesthesia system; covering head, trunk, upper limbs and unoperated lower limb
Borms 1994
Trial held in Belgium
Inclusion: total hip arthroplasty
Exclusion: no patients had infections, fever, metabolic disease including diabetes and thyroid dysfunction
Age (range):68.5(55–75); gender (m/f): 5:15
Comorbidities: not stated; IV fluid warmed to 37°C; inspiratory gases humidified by hme; or temperature −19°C; ventilation: maintain PET CO2 35 mmhg; gas flow: 4l/min; in ventilation: maintain PET CO2 both groups, the dependent leg was covered with single layer of cotton shirt and disposable surgical drape
  1. FAW, lower body cover (model 525, Augustine medical inc + single blanket + warmed IV fluid (active warming device; duration: applied immediately after patients positioned laterally; ‘high’ −40°C; n=10
  2. Reflective thermoplastic aluminium composite (thermo-lite) + warmed IV fluid (thermal insulation); duration: not stated; n=10
Bourke 1984(study 1)
Trial held in USA
Type of surgery: carotid endarterectomy
Age (range):not stated; gender (m/f): not stated
comorbidities: not stated; or temperature: 19.5°C; humidity: 47%
  1. Aluminized blanket + surgical drape (thermal insulation; duration: not stated; n=30
  2. Surgical draping usual care; duration: not stated; n=30
Bourke 1984(study 2)
Trial held in USA
Patients undergoing neurosurgery. Age (range):not stated; gender (m/f): not stated
Comorbidities: not stated; all patients rested on active warming blankets, equilibrated to room temperature. device turned on between 3–4hrin the control group. Or temperature: 19.7°C; humidity: 49%; shivering not assessed as some patients remained intubated and paralysed
  1. Aluminized blanket (thermal insulation; duration: not stated; n=15
  2. Usual care (active warming device); duration: not stated; n=15
All patients rested on an active heating pad equilibrated to the room temperature; this was turned on after 3 hr for the patients in the control group
Camus 1993a
Trial held in France
Inclusion: surgery lasting 2h; none were obese, febrile, or had a history of endocrine disease
Age (range):48.5 years; gender (m/f): 10:12
comorbidities: not stated; IV: ambient temperature; irrigation fluids: 37°C; or temperature: 20°C; lungs ventilated via a semi closed circle system, 2l/min of fresh gas flow to maintain end-tidal pCO2 at 30–35 mmHg. Inspiritaory gases not warmed; opioids not administered during recovery from anaesthesia
  1. Elecontrol group warming blanket (cm-an 220, chromex; 120 cm wide (active warming device; duration: positioned as soon as patients lay on or table; 42–43°C; n=11
  2. usual care; duration: not stated; n=11
Camus 1993b
Trial held in France
Inclusion: surgery lasting 2 hr; none were obese, febrile, or had a history of endocrine disease
Age (range):48.5 years; gender (m/f): not stated
comorbidities: not stated; IV: ambient temperature; irrigation fluids: 37°C; or temperature: 21.5°C; lungs ventilated via a semi closed circle system, 2l/min of fresh gas flow to maintain end-tidal pCO2 at 30–35 mmhg. inspiritaory gases not warmed; opioids not administered during recovery from anaesthesia
  1. 1 insulated lower body forced-air blower cover (Bair hugger model 200, augustine medical + 2 cotton sheets (active warming device; duration: not stated; 43°C; n=11
  2. usual care; duration: not stated; n=11)
  3. Lower body forced air blower (Bair hugger model 200, augustine medical); 43°C
Camus 1993b2
Trial held in France
Inclusion: surgery lasting 2 hr; none were obese, febrile, or had a history of endocrine disease
Age (range):48.5 years; gender (m/f): not stated
comorbidities: not stated;
IV ambient temperature; irrigation fluids: 37°C; or temperature: 21.5°C; lungs ventilated via a semi closed circle system, 2l/min of fresh gas flow to maintain end-tidal pCO2 at 30–35 mm Hg. Inspiratory gases not warmed; opioids not administered during recovery from anaesthesia
  1. 1 lower body forced-air blower cover (Bair hugger model 200, augustine medical + 2 cotton sheets (active warming device; duration: not stated; 43°C; n=11
  2. usual care; duration: not stated; n=11
  3. Lower body forced air blower (Bair hugger model 200, augustine medical); 43°C
Camus 1997
Trial held in France
Inclusion: non-haemorrhagic abdominal surgery in the supine position; at least 2 hrs
Age (range):50 (24–65) years; gender (m/f): not stated
comorbidities: not stated; or temperature: 20.5°C (SD 0.1); lower body FAW (Bair hugger model 500e)set high(43°C) applied to control group (n=3/8) when temperature decreased < 35°C; IV fluids: RT; mean IV fluids: 1.7(SD 0.l); no postoperative thermal skin lesions were detected
  1. 2 electric group blankets (ElectroConcept); model cb2 (covered leg. To pubis); model cb3 (over head, trunk and arms) + single cotton sheeting between skin and blanket (active warming device); duration: blanket 1: once on or table; blanket 2: after tracheal intubation; 40°C; n=10
  2. Usual care; duration: not stated; n=8
Casati 1999
Trial held in Italy
Inclusion: patients undergoing total hip asthroplasty
Exclusion: patients with severe CV and respiratory disease, obese, thyroid disease, dysautonomi or Raynaud’s syndrome
Age (range):68 years (SD 11): 66 (SD 7); gender (m/f): not stated; Duration of surgery: 100 min (SD 37): 105 (SD 18);
comorbidities: not stated; 3 ml of Ringer’s solution infused every 1 ml of blood loss; all patients were in supine position; autologus blood warmed to 37°C before infusion
  1. Forced air warming (Bair Hugger) + IV Ringer’s solution (37°C) (active warming device); duration: after loss of sensation at t10 until end of surgery; not stated; n=25
  2. Reflective blankets (thermal insulation); duration: after loss of sensation at t10 until end of surgery; n=25
Dyer 1986
Trial held in Australia
Inclusion: transurethral resection of prostate under spinal anaesthesia
Age (range):69 years; gender (m/f): 100:0
comorbidities: not stated; theatre temperature: 20.7–21.3;
resection time: w: 25.4 min(SD 10.8)vs c: 32.4(SD 15.4)
  1. Reflective blanket (thermal insulation); duration: not stated; n=24
  2. usual care; duration: not stated; n=25
Erickson 1991
Trial held in USA
Inclusion: at least 21y age major nonvascular abdominal
Exclusion: preoperative fever (oral temperature > 37.8°C); personal or family history of malignant hyperthermia, limb amputation, or pregnancy; unable to give informed consent; spinal or epidural anaesthesia; lithotomy position
Age (range):51.6 (25–80); gender (m/f): 11:49
comorbidities: not stated; in this part of the study: 6:24 (m:f); type of surgery: upper abdominal gastrointestinal surgery (cholecystectomy, colon resection, gastrectomy, exploratory laparotomy=33); lower abdominal gynaecologic procedures (abdominal hysterectomy, oophorectomy; n=27
  1. Thermadrape head and body cover + warmed blankets; n=15) (thermal insulation); duration: not stated; n=15
  2. Thermadrape body cover + warmed blankets; n=3/15) usual care; duration: not stated; n=15
  3. Head and body covers 4 body covers only
Frank 1995
Trial held in USA
Inclusion: patients age > 60 years; scheduled for lower vascular, abdominal or thoracic procedures; presence of 2 or more risk factors for CAD
Exclusion: patients with ECG abnormalities, preoperative temperature < 36°C or > 38°C; history of Raynaud’s or thyroid disease
Age (range):71 (SEM 1); gender (m/f): 85:82
comorbidities: not stated; room temperature: 21°C; endotracheal tube removed at end of surgery unless standard extubation criteria not met; in PACU for the control group: warmed blankets placed over patients at nurse’s discretion; FAW group: intervention continued for 2 hr and similar to control group
  1. Forced-air warming cover (Mallinckrodt Medical) + IV fluid and blood warmed (model bw-5) + HME (thermovent) (active patients + active fl); duration: not stated; set at height and adjusted to maintain core temp at 37°C; n=37
  2. Warmed IV fluids (usual care+ active fl); duration: not stated; n=37
Frank 1997
Trial held in USA
Inclusion: patients age > 60 years; scheduled for peripheral vascular, abdominal or thoracic procedures; scheduled for postoperative admission to theICU; documented or at high risk of CAD (age criterion to preselect patients at risk for both perioperative CV complications and inadvertent hypothermia)
Exclusion: patients with ecg abnormalities, preoperative temperature < 36°C or > 38°C; patients with Raynaud’s or thyroid disease
Age (range):71; gender (m/f): 85:82
comorbidities: not stated; room temperature: 21°C; endotracheal tube removed at end of surgery unless standard extubation criteria not met; surgery duration 3.4 and 3.6h (SEM 1.1)
  1. Forced-air warming cover (Mallinckrodt Medical) + IV fluid and blood warmed (model bw-5) + HME (thermovent) (active patients + active fl); duration: not stated; set to maintain core temp at 37°C; n=142
  2. 1 layer of paper of surgical field+ IV fluid and blood warmed + heat moisture exchanger (usual care+ active fl); duration: not stated; n=158
Harper 2007
Trial held in UK
Inclusion: non-emergency vascular, general, breast and gynaecological surgery. Age (range):58 years; gender (m/f): not stated. Comorbidities: not stated; all patients received warmed IV fluids
  1. Bair hugger (Actamed) (active warming device); duration: not stated; set at maximum; n=19
  2. Full length electric warming mattress (Inditherm) (active warming device); duration: not stated; 37°C; n=21
Hindsholm 1992
Trial held in Denmark
Surgery: total hip arthroplasty for osteoarthritis
Age (range):43–82; gender (m/f): 17:13
comorbidities: not stated; ambient or temperature: 21°C with air renewal 20 times per hour; Blood and IV fluid infusions heated to 37°C; Number randomised to each group not given; assuming 15 patients in each group
  1. Reflective blanket (Sunflex aluminised plastic sheetings) + cotton gown + standard or draping (thermal insulation); duration: from the anaesthetic room; n=15
  2. Cotton gown+ standard or draping (3 weave cotton blankets) usual care; duration: not stated; n=15
Hofer 2005
Trial held in Switzerland
Inclusion: Patients undergoing elective multiple off-pump coronary artery bypass grafting, with preserved left ventricular function (ejection fraction >40%), absence of platelet glycoprotein inhibitor therapy, preoperative hematocrit 30% or higher, preoperative normothermia and no pre-existing coagulation disorders. Age: 66.3 years (SD 10.9): 64.4 (SD 10.7): 65.6 (SD 11.8); gender (m/f): 72:18; All patients received warmed transfusions (40°C); Duration of surgery: 232 min (SD 65): 248 (SD 46): 249 (SD 68)
  1. Forced air warming (Warm Touch; Mallinckrodt Inc); (active warming device); duration:after induction of anaesthesia; 42°C; n=29
  2. Electric blanket (Thermamed SmartCare OP; (active warming device) system); duration:after induction of anaesthesia; 42°C; n=30
  3. Water garment (Allon 2001 system; MTRE); (active warming device); duration:after induction of anaesthesia; 36.7°C; n=29
Hoyt 1993
Trial held in USA
Inclusion: at least 18 years old, intubated and mechanically ventilated, anaesthesia gas flow maintained at no greater than 3l after induction and having a blanket warmer, fluid warmer and humid vent. Exclusion: preoperative temperature > 38°C and those receiving progesterone or testosterone. Age (range):47.5 years; gender (m/f): not stated. Comorbidities: not stated; temperature of IV fluids and blanket warmers not stated
  1. Insulated head cover (Thermadrape) (thermal insulation); duration: applied upon arrival into or; n=13
  2. Paper head cover (Kimberly-Clark) usual care; duration: not stated; n=17
Hynson 1992
Trial held in USA
Included: kidney transplant patients with history of insulin-dependent diabetes, CV disease, hypertension or medication history
Exclusion: obesity (150% of ideal body weight), peripheral vascular disease, limb amputation or preoperative infection or fever
Age (range):not stated; gender (m/f): 4:6
comorbidities: not stated; IV fluids: warmed to 37°C; ambient room temperature: 20°C; gas flow maintained at 5l/min; ventilation was controlled to maintain end tidal PetCO2 near 35 mm Hg
  1. Full length circulating water blanket (Blanketrol 200) covered by single layer cotton sheet (active warming device); duration: 180 min; 40°C; n=5
  2. Standard surgical draping usual care; duration: not stated; n=5
  3. Forced air warming (bair hugger) set at 43°C; lower-body warming blanket placed over the legs to the mid-thigh.; n=5
  4. Inspired gas set at 40°C; n=5
Janicki 2001
Trial held in USA
Patients undergoing open abdominal surgery; Exclusion: pregnant, current fever (core temperature > 38°C), septic condition within 3 days before the study, burn or multiple traumatic injuries, abdominal procedures involving rectal manipulation and surgery in lithotomy position
Age (range):54.5 years (37.9–67.9); gender (m/f): 29:24 comorbidities: not stated; ASA: II–IV; ambient or temperature: 20.4°C; water garment group: lower and upper extremities, upper anterior, lateral portions of the chest and entire back of the patients whose temperature decreased to less than 34.5°C the room was warmed to 24°C to assist with patient rewarming; ambient temperature in PACU not controlled
  1. Water-garment warmer (Allon, MTRE, advanced technologies) (active warming device); duration: before induction; 36.8°C; n=25
  2. Bair hugger warming (model 505) and bair-hugger upper body warming blanket (model 52(active warming device); duration: not stated; 43°C; reduced to 'medium': 36°C if patient core temperature > 37°C; n=28
Janicki 2002
Trial held in USA
Patients undergoing liver transplantation.
Exclusion: pregnant, current fever (core temperature > 38°C), septic condition within 3 days before the study, burn or multiple traumatic injuries, abdominal procedures involving rectal manipulation and surgery in lithotomy position. Age (range): 50(18–65); gender (m/f): 12:12 comorbidities: not stated; ASA: II–IV; ambient OR temperature: 20.4°C; water garment group: lower and upper extremities, upper anterior, lateral portions of the chest and entire back of the patients whose temperature was less than 34.5°C; room warmed to 24°C to assist with patient rewarming; ambient temperature in PACU not controlled
  1. Water-garment warmer (Allon, MTRE, advanced technologies) (active warming device); duration: before induction; 36.8°C; n=12
  2. Bair Hugger warming (Model 505) and Bair Hugger upper body warming blanket (model 52(active warming device); duration: not stated; 43°C; reduced to 'medium': 36°C if patient core temperature > 37°C; n=12
Joachimsson 1987
Trial held in Sweden
Inclusion: patients undergoing gastric, small and larger intestine or gall bladder operations. Exclusion: criteria not stated. Age (range):56; gender (m/f): 37:31. Comorbidities: not stated; infused blood and colloids passed through blood warmers at 37–38°C; relative humidity: 40–50%; or temperature: 22°C
  1. Hot-water mattress (Heto, Bikerod) (active warming device); duration: not stated; 39°C; n=21
  2. usual care; duration: not stated; n=24
  3. Heated-humidifier; 38°C
Johansson 1999
Trial held in Sweden
Inclusion: elective total unilateral primary hip arthroplasty, no pathologic fracture, no anamnestic evidence of coagulopathy, and prothrombin and activated partial thrombin time within normal limits. Age (range):69 (SD 7): 67 (SD 7); gender (m/f): 21:29; comorbidities: not stated; Duration of surgery: 102 min (SD 20): 100 min (SD 23); Premedication: diazepam, 5 mg by mouth used for sedation; ephedrine (5(7.6) v 4.3(6) mg); midazolam IV (2(1.8) v 1.3(1.5)mg); NSAIDs/aspirin discontinued 1 wk before operation in 8 patients in each group; fl and blood warmed; or temperature: 20.9°C
  1. Bair hugger (Augustine Medical) + pre-warmed gel-filled mattress + warmed fluids (active patients + active pt); duration: not stated; n=25
  2. Usual care + pre-warmed gel-filled mattress + warmed fluids (active warming device); duration: not stated; n=25
Kabbara 2002
Trial held in USA
Inclusion: gynaecologic, orthopaedic, otolaryngologic, plastic or general lasting 20 min or more
Exclusion: emergency surgery, pregnant, heat injury, preoperative sublingual temperature < 35.5°C or > 38°C, planned ICU administrated postoperative, use of calcium channel blocker, and history of malignant hyperthermia
Age (range):43.5 years; gender (m/f): 26:57
Comorbidities: not stated; ward temperature. Exclusion: 21°C; fluids at rt where clinically indicated; fresh gas flow of 2l/min
  1. Bair Hugger (Augustine Medical) (active warming device); duration: intraoperative period; 43°C; n=45
  2. Standard hospital blankets usual care; duration: not stated; n=42
Kamitini 1999
Trial held in Japan
Inclusion: ASA I–III elective abdominal sugary
Exclusion: preoperative fever or who received a vasodilator on day surgery
Age (range):66; gender (m/f): not stated
  1. Reflective sheets (thermal insulation); duration: not stated; n=22
  2. Reflective sheets (thermal insulation); duration: not stated; only the extremities and trunk; n=22
Kurz 1995
Trial held in USA
Inclusion: ASA I–III patients undergoing colon surgery; none of the patients had a history of thyroid disease, dysautonomia, Raynaud's syndrome or malignant hyperthermia
Age (range):58(18–80 years); gender (m/f): 108:92
comorbidities: not stated; room temperature: 21–22°C intraoperative; 23–25°C postoperative; if patient core temperature approached 34°C, FAW was instituted to prevent further hypothermia
  1. Forced air cover (Augustine Medical) + warmed IV fluids (active warming device); duration: not stated; 40°C; n=39
  2. IV fluids - not warmed usual care; duration: not stated; not stated; n=35
Kurz 1996
Trial held in USA
Inclusion: colorectal resection for cancer or IBD; surgery duration 3.1 h (SD 1.0)
Exclusion: patients scheduled for minor colon surgery, use of corticosteroids or other immunosuppressive drugs including cancer chemo 4 weeks before surgery; recent history of fever, infection or both; serious malnutrition or bowel obstruction
Age (range):60 years (18–80); gender (m/f): 108:92
comorbidities: not stated; inflammatory bowel disease; mechanical bowel prep night before surgery
  1. Forced air cover (Augustine Medical) + warmed IV fluids (fluid warmer)-activated (active warming device); duration: not stated; 40°C; n=104
  2. Forced air cover (Augustine Medical) + warmed IV fluids (fluid warmer)- not activated (active + passive); duration: not stated; 'ambient temperature’; n=96
Kurz 1993a
Trial held in Austria
Inclusion: patients undergoing maxillofacial surgery, including node resection and flap reconstruction; none of the patients had history of fever, thyroid disease, dysautonomia, Raynaud's syndrome or malignant hyperthermia.
Age (range):58 years; gender (m/f): not stated comorbidities: not stated; or temperature: 21°C; anaesthetic gases: via circle system using fresh gas flow of 6l/min; fluids administered intravenously warmed to 37°C; type of surgery: maxillofacial; reports no significantly different in m:f but numbers not given
  1. Convective warming (Bair Hugger, model 500; augustine medical) (active warming device); duration: after induction of anaesthesia; 40°C (high); n=8
  2. Full-length circulating water mattress (Aquamatic module, Hamilton Inc) (active warming device); duration: after induction of anaesthesia; 40°C; n=8
Kurz 1993b
Trial held in Austria
Inclusion: patients undergoing total hip arthroplasty or femoral resection for tumour in supine position; none of the patients had history of fever, thyroid disease, dysautonomia, Raynaud's syndrome or malignant hyperthermia.
Age (range):58 years; gender (m/f): not stated; comorbidities: not stated; or temperature: 21°C; anaesthetic gases: via circle system using fresh gas flow of 6l/min; fluids administered intravenously warmed to 37°C
  1. Convective warming (Bair Hugger, model 500; augustine medical) (active warming device); duration: after induction of anaesthesia; 40°C (high); n=8
  2. Full-length circulating water mattress (Aquamatic module, Hamilton Inc) (active warming device); duration: after induction of anaesthesia until not stated; 40°C; n=8
Lenhardt 1997
Trial held in USA
Inclusion: patients aged 18–80 years undergoing abdominal surgery (colon resection with or without abdominal peritoneal pull stable, systemic disease); ASA I–III; Exclusion: patients scheduled for minor abdominal surgery; Duration of surgery: 3.4 hours (SD 1.2): 3.2 (SD 1.1)
Age (range):56 (SD 17): 55 (SD 16); gender (m/f): 74:76
Comorbidities: not stated; 100 of the patients participated in kurz 1996
  1. Extra warming (active warming device); duration: not stated; core temperature maintained near 36.5°C; n=74
  2. usual care; duration: not stated; n=76
Leung 2007
Trial held in Hong Kong, People’s Republic of China
Inclusion: age 18–80 years, ASA I–III and elective laparotomy
Exclusion: pregnancy, core temp ≥ 37.5°C
Age (range):65 years; gender (m/f): 39:21
comorbidities: not stated;
  1. Upper body forced-air warming (Bair Hugger, augustine medical) (active warming device); duration: after induction until end of surgery; 43°C; n=30
  2. Elecontrol group heating pad (Operatherm 20+ prewarmed gel pad (active warming device); duration: not stated; 39°C; n=30
Lindwall 1998
Trial held in Sweden
Inclusion: ASA I–IV patients for extensive operations for oesophageal, rectal or bladder carcinomia with duration of surgery and anaesthesia greater than 3 hours; exclusion criteria not stated
Age (range):65.5 years; gender (m/f): not stated
comorbidities: not stated; active fluid warming in both groups (38–39°C); low flow anaesthesia with fresh gas flow of 0.7–1.2 l/min
  1. Upper or lower forced air [Bair Hugger (Model 500) (Augustine Medical)] (active patients + active fl); duration: started before induction of anaesthesia and stopped at end of operation; 43°C (SD 2.3); n=12
  2. Double layers of terry cloth + operation drapes usual care; duration: not stated; n=13
Mason 1998
Trial held in USA
Inclusion: Roux-en-y gastric bypass surgery for morbid obesity
Exclusion criteria not stated
Age (range): 38.5 (SD 6.1): 40.7 (SD9.6); (17–59 years); gender (m/f): 9:55; Duration of surgery: 156.1 min (SD 27.4): 156.9 (SD 31.6)comorbidities: not stated; or temperature: 20.9°C; PACU temperature: 24.75°C
*significantly different between the groups length of incisim (cm). Length of incision longer in warmed blanket group
  1. Forced air warming [Bair Hugger (Model 500 Augustine Medical)] (active warming device); duration: not stated; 'medium'= 38°C (SD 3); n=32
  2. Warmed cotton blankets (active warming device); duration: not stated; n=32
Matsukawa 1994
Trial held in Japan
Inclusion: abdominal surgery (subtotal gastrectomy, total gastrectomy, or cholecystectomy) scheduled to last at least 2h
Exclusion criteria not stated
Age (range):61.5; gender (m/f): 27:13
comorbidities: not stated; or temperature: 24–26°C; Ringer's lactate solution administered to all patients
  1. Forced air warming (Bair Hugger) + circulating blanket warming (KR-thermia RK600) (active patients + active pt); duration: unclear; 38°C (FAW) + 37°C (circulating blanket); n=20
  2. Circulating blanket warming (KR-Thermia RK600) (active warming device); duration: unclear; 37°C; n=20
Matsuzaki 2003
Trial held in Japan
Exclusion: patients with preoperative fever, evidence of current infection, thyroid disease or disturbance of autonomic function
Age (range): 55 years (20–80); gender (m/f): 15:9
comorbidities: not stated;
  1. Upper body forced air over (Warm touch; Tyco-Mallinckrodt) (active warming device); duration: after induction of GA and maintained through surgery; set to medium; n=8
  2. Full length circulating water mattress (active warming device); duration: after induction of GA and maintained through surgery; set to medium (38°C); n=8
  3. Carbon-fibre resistive heating blanket (SmartCare OP); duration:after induction of GA and maintained through surgery;set to medium (38°C); n=8
Mogera 1997
Trial held in India
Inclusion: intracranial surgery lasting at least 4 hours
Exclusion: obese, febrile, or had a history of endocrine diseases
Age (range):47 years; gender (m/f): 18:12
comorbidities: not stated; IV fluids- ambient temperature
  1. Convective warm air blanket (Bair Hugger, Augustine) (active warming device); duration: not stated; n=15
  2. Cotton sheet (usual care); duration: not stated; n=12
Motamed 2000
Trial held in France
Inclusion: long-lasting abdominal surgery
Exclusion: history of renal, hepatic or neuromuscular disease and taking medications known to interfere with neuromuscular function, e.g. Patients with electrolyte abnormality, diabetes and those with an anticipated difficult airway; patients with drawn if surgery < 2 hr
Age (range):56 years (SD 15): 50 (SD 14); gender (m/f): 17:9
comorbidities: not stated; room temperature: at 21°C
  1. Upper FAW (Warm Touch, Mallinkrodt) (active warming device); duration: not clearly stated; 43°C; n=13
  2. Lower FAW (Warm Touch, Mallinkrodt) (active warming device); duration: not clearly stated; 43°C; n=13
Muller 1995
Trial held in Austria
Inclusion: orthotropic liver transplant
Exclusion criteria not stated
Age (range):52.5 years; gender (m/f): 15:5
Comorbidities: not stated; IV fluids warmed to 37°C
  1. Forced air warming + circulating water mattress(full length) (American Pharmaseal Company) (active warming device); duration: not stated; 42°C; n=10
  2. Circulating water mattress(full length) (American Pharmaseal Company) (active warming device); duration: not stated; n=10
Negishi 2003
Trial held in USA
Inclusion: open abdominal surgery
Exclusion: preoperative fever, evidence of current infection, thyroid disease or dysautonomia
Age (range):62 years (20–80); gender (m/f): 15:9 comorbidities: not stated; ambient temperature: near 22°C; all fluids warmed to 37°C
  1. Full-length circulating-water mattress (Meditherm; Gaymar Industries Inc)with 5 mm pad placed between mattress and patients (thermal insulation); duration: not stated; 42°C; n=8
  2. Forced-air cover (Bair Hugger) (active warming device); duration: not stated; set to high n=8
  3. Restive heating blanket (Smartcare; Thermamed gmbh) set at 42°C overed one arm, the chest and both legs
Ng 2006
Trial held in Hong Kong, People’s Republic of China
Inclusion: age 18–80 years, ASA I–III and elective total knee replacement
Exclusion: pregnancy, core temp ≥ 37.5°C; history of heat injury; contraindication to neuraxial blockade
Age (range):67; gender (m/f): 17:43
  1. Upper body forced-air warming (Bair Hugger, Augustine Medical) (active warming device); duration: after induction until end of surgery; 43°C; n=30
  2. Electric heating pad (Operatherm 20+ prewarmed gel) pad (active warming device); duration: not stated; 39°C; n=30
Ouellette 1993
Trial held in USA
Inclusion: patients undergoing cervical or lumbar laminectomy with duration of at least 90 min
Exclusion criteria not stated
Age (range):44 years; gender (m/f): not stated
Comorbidities: not stated; IV fluids administered at room temperature; room temperature: 20–21°C
  1. Bair Hugger forced air warming (active warming device); duration: not stated; set on 'low'; n=12
  2. usual care; duration: not stated; n=not stated
  3. Reflective blanket over upper and lower extremities; n=12; inspired, heated, humidified air (Maquest sct 2000) at 39°C; n=12
Radel 1986
Trial held in USA
Inclusion: orthopaedic surgery on lower extremities of 1 hour duration or greater. Patients selected had no skin lesions or burns of chest, back or scalp; no pre-existing medical conditions precluding use of rectal and oesophageal probes; oral temperature < 38°C or less than 1 hour prior to induction
Age (range):23–92 years; gender (m/f): 30:0
Comorbidities: not stated
  1. Circulating water vest and cap (Gaymar Meditherm) + IV fluids (active warming device); duration: not stated; water fluid at a temperature of 38°C; IV fluids: 37°C; n=10
  2. 2 cotton sheets and patient gown+ IV fluids usual care; duration: not stated; warmed IV fluids: 37°C; n=10
  3. Insulated usual care; 2 cotton blankets and shirts and a cotton skull cap; n=10
Radford 1979
Trial held in UK
Inclusion: patients undergoing craniotomy for intracranial tumours or aneurysms in supine position
Exclusion: patients younger than 14 years and those with pyrexia before operation
Age (range):48.5; gender (m/f): 22:20
comorbidities: not stated; significantly different in baseline core temperature. Anaesthetic gases not warmed or humidified; infused blood (rarely given)not warmed; or other infusions not warmed; theatre temperature (start of operation): 22.2°C; end of operation: 23.7°C
  1. Metallized plastic sheet (thermal insulation); duration: not stated; n=20
  2. Cotton gown and 1 cotton blanket usual care; duration: not stated; n=22
Rasmussen 1998
Trial held in Denmark
Inclusion: colonic resections or rectal amputations lasting at least 2 hours
Exclusion: fever, metabolic disorder, BMI > 30 kg/m2, ongoing treatment with ß-blocking agents or neuromuscular disease
Age (range):67(49–80 years); gender (m/f): 10:14
comorbidities: not stated; fresh gas flow: 1.5–3.0 l/min into a semi closed circle system with CO2 absorption IV fluid: room temperature; blood humidity, blood transfusion: 37°C through heating device; room temperature: 21°C
  1. Bair Hugger (Augustine Medical) + prewarmed gel mattress (active patients + active pt); duration: from the or; unclear when warming ceased; BH: 43°C; gel mattress: 40°C; n=8
  2. Prewarmed gel mattress (active warming device); duration: from the or rm; unclear when warming ceased; 40°C; n=8
  3. 8 patients randomised to oesophageal heat exchanger. [GDGagreed this is not common practise within the UK]
Russell 1995
Trial held in UK
Exclusion: patients with fulminant liver disease; history of previous upper abdominal surgery
Age (range):45.8 years; gender (m/f): 29:31
comorbidities: not stated; ward temperature: not stated; irrigation and IV fluid: warmed to 37°C; anaesthetic gases: admin via a circle breathing system with fresh gas flow of 3 l/min
  1. FAW under mattress (Howarth) + warmed IV and irrig fluid (37°C) (active warming device); duration: not stated; 40°C; n=20
  2. Electric under blankets (JMW medical) + warmed IV and irrig fluid (37°C) (active warming device); duration: not stated; 39°C; 41°C; n=20
  3. FAW over blanket (Mallinkrodt); set to high (42–48°C) resets to medium (36–41.5°C) after 45 min
Scott 2001
Trial held in UK
Inclusion: Patients over 40 years undergoing orthopaedic, colorectal, gastrointestinal, urological and vascular surgery; ASA I–IV; undergoing major surgery with an expected hospital stay of 5 days; no existing sacral pressure ulcers and provided informed consent
Exclusion: patients undergoing procedures in which intraoperative warming standard practice; lateral or prone position
Age (range):68.4 years (SD 9.1): 68.2 (SD 9.2) (41–89); gender (m/f): 149:175; Duration of surgery: 111 min (SD 47.4): 115.5 (SD 46.8);
comorbidities: not stated; 27 protocol violations; 17 patients allocated to warming treated as usual care and 10 patients assigned to usual care given warming because of clinical need; some control patients may have received warmed IV fluids
  1. Forced air warming + warmed IV fluids (active warming device); duration: not stated; n=161
  2. Usual care + warmed IV infusions, as determined by clinical need.usual care; duration: not stated; n=163
Sheng 2003
Trial held in USA
Exclusion: use of corticosteroids or immunosuppressive drugs (including cancer chemotherapy) 4 weeks prior to surgery, recent history of fever, infection or both; serious malnutrition (low serum albumin, a low wbc or loss of more than 20 % of body weight)
Age (range):37.5 years; gender (m/f): 23:30
comorbidities: not stated; outpatient setting surgery; holding room temperature: not stated; or temperature: 21°C; IV fluid: room temperature; ASA: I–III
  1. Reflective blanket (thermal insulation); duration: on arrival into outpatient clinic till prior to transfer to or; n=30
  2. Usual care; duration: not stated; n=23
Sheng 2003 (1b)
Trial held in USA
Inclusion: ASA I–III
Exclusion: use of corticosteroids or immunosuppressive drugs (including cancer chemotherapy) 4 weeks prior to surgery, recent history of fever, infection or both; serious malnutrition (low serum albumin, a low wbc or loss of more than 20 % of body weight)
Age (range):37.5 years; gender (m/f): 23:30
comorbidities: not stated; outpatient setting surgery; holding room temperature: not stated; or temperature: 21°C; IV fluid: room temperature
  1. Reflective blanket(Thermo-lite) (thermal insulation); duration: on arrival to or; n=26
  2. Cloth blanket usual care; duration: not stated; n=26Patients randomised to hat/jackets in the preoperative phase
Smith 1994
Trial held in USA
Inclusion: outpatients scheduled for arthroscopic knee surgery
Exclusion criteria not stated
Age (range):35 years (SEM 1.5): 34 (SEM 1.9); gender (m/f): 79:48; Duration of surgery: 56 min (SEM 1.9): 53 (SEM 2.6)
comorbidities: not stated;
  1. Forced air cover (Bair Hugger, model 500; Augustine Medical) + warmed cotton blankets (active warming device); duration: not stated; n=31
  2. Warmed cotton blankets usual care; duration: not stated; 60°C; n=21; warming continued in PACU; smith 1994a: patients not warmed in PACU
Smith 1994a
Trial held in USA
Inclusion: outpatients scheduled for arthroscopic knee surgery
Exclusion criteria not stated
Age (range):34.5 years; gender (m/f): 79:48
comorbidities: not stated; Patients not warmed in PACU
  1. Forced air cover (Bair Hugger, model 500; Augustine Medical) + warmed cotton blankets (active warming device); duration: not stated; n=38
  2. Warmed cotton blankets usual care; duration: not stated; 60°C; n=37;
Tølløfsrud 1984a
Trial held in Norway
Inclusion: 40 patients scheduled for surgery on the abdominal aorta (straight or bifurcated prosthesis)
Exclusion: patients with body temperature of over 37.5°C o under 36.5°C on the morning of surgery
Age (range):64; gender (m/f): 8:2
comorbidities: not stated; blood and plasma warmed to 37°C
  1. Warming blanket(Gorman Rupp); 45x60 cm (active warming device); duration: not stated; 38–40°C; n=10
  2. Usual care usual care; duration: not stated; n=10
  3. Warming blanket + heated humidifier; n=10
  4. Heated-humidifier(Bennett cascade humidifier) 37–40°C; n=10
Tølløfsrud 1984b
Trial held in Norway
Inclusion: 40 patients scheduled for extra-abdominal vascular surgery (femoropopliteal bypass and profunda plasty)
Exclusion: patients with body temperature of over 37.5°C o under 36.5°C on the morning of surgery
Age (range):70; gender (m/f): 8:2
Comorbidities: not stated; blood and plasma warmed to 37°C
  1. Warming blanket(Gorman Rupp); 45x60 cm (active warming device); duration: not stated; 38–40°C; n=10
  2. Usual care usual care; duration: not stated; n=10
  3. Warming blanket + heated humidifier; n=10
  4. Heated-humidifier (Bennett cascade humidifier) 37–40°C; n=10
Torrie 2005
Trial held in New Zealand
Inclusion: males ASA I–III scheduled for TURP
Exclusion: age less than 55 or greater than 90 years; thyroid dysfunction; weight less than 50 kg or greater than 120 kg; ASA > III; indwelling urinary catheter or urinary tract infection; core temperature ≥ 37.5°C
Age (range):72.5 years; gender (m/f): 60:0
Comorbidities: not stated;
  1. Forced air warming (Bair Hugger, Augustine Medical) + warmed iv(hotline)+warmed irrigation fluid(warming cabinet) (active warming device); duration: not stated; FAW: 43°C; IV: 41°C; irrigation: 42°C; n=32
  2. Radiant warming (Sun Touch) + warmed IV fluids(Hotline) + warmed irrigation fluids (warming cabinet) (active warming device); duration: not stated; radiant: 41°C; IV: 41°C; irrigation: 42°C; n=28
Whitney 1990
Trial held in USA
Inclusion: intra abdominal gynaecological surgery of at least 1.5 hrs
Exclusion criteria not stated
Age (range):40.5; gender (m/f): 0:40
comorbidities: not stated; concurrent treatments: not stated; theatre temperature:, irrigation fluid: not stated; humidity: not stated;, air flow: not stated; HME utilised
  1. Warmed cotton thermal blanket (active warming device); duration: prior to induction; not stated; when removed; not stated; n=20
  2. Thermadrape (OR concepts); reflective blanket is an aluminium impregnated plastic material (thermal insulation); duration: prior to induction; not stated; when removed; n=20
Winkler 2000
Trial held in Austria
Inclusion: patients scheduled to undergo primary, unilateral, cement-free total hip arthroplasty. None performed for treatment of tumour
Exclusion: preoperative coagulation tests abnormal, aspirin products consumed within a week of surgery, history of bleeding disorders, dvt, pulmonary embolism
Age (range):64.5 (40–80)years; gender (m/f): 65:85
comorbidities: not stated; concurrent treatments, ward temperature, irrigation fluid, IV fluid, humidity, air flow
  1. Forced air covers attached to individual forced air heater (Bair Hugger, Augustine Medical) (active warming device); duration: not stated; temperature adjusted to maintain core temp at 36.5°C; n=75
  2. Forced air covers attached to individual forced air heater(Bair Hugger, Augustine Medical) (active warming device); duration: not stated; temperature adjusted to maintain core temp at 36.0°C; n=75
Wong 2004
Trial held in New Zealand
Inclusion: 20–60 yearss; weight: 50–110 kg; laparoscopic cholecystectomy
Exclusion: patients presenting with pre-existing hyperp yrexia, history of malignant hyperthermia, or currently taking antipyretic medication
Age (range):39.3 (26.5–50.3 years) gender (m/f): 0:42
Comorbidities: not stated; mean theatre temperature: a: 21.6°C (SD 1.1); b: 22.2°C (SD1.2) mean theatre humidity: a: 46% (SD4); b: 45% (SD 5).IV fluid: for all patients prewarmed to 42°C. All patients covered in thin hospital blankets covering torso, arms and legs followed by drape
  1. Sun touch (Fisher and Paykel healthcare, NZ) (active+ thermal insulation); duration: after patients placed on operating table; temperature setting at 41°C; n=21
  2. Bair Hugger (Augustine Medical, USA) (active + passive); duration: after patients placed on operating table; temperature setting at 43°C; n=21
Yamakage 1995
Trial held in Japan
Inclusion: spinal anaesthesia for surgery on the lower abdomen or a lower extremity
Exclusion: patients with history of smoking or extreme obesity (BMI > 30 kg/m2)
Age (range):56.2 years (45–72); gender (m/f): 6:8
comorbidities: not stated; IV: 37°C; OR temperature: 23°C
  1. Forced air warming (Bair Hugger) + warmed IV fluids (active warming device); duration: 90 min; set to ‘medium’ −37°C; n=7
  2. Cloth blanket + warmed IV fluids usual care; duration: not stated; n=7
  3. Bair Hugger (lower body); [below T10]; n=7

From: APPENDIX C, CHARACTERISTICS OF INCLUDED STUDIES

Cover of The Management of Inadvertent Perioperative Hypothermia in Adults
The Management of Inadvertent Perioperative Hypothermia in Adults [Internet].
NICE Clinical Guidelines, No. 65.
National Collaborating Centre for Nursing and Supportive Care (UK).
Copyright © 2008, National Collaborating Centre for Nursing and Supportive Care.

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