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Purpose To determine if implementing a normothermia bundle, which includes preoperative forced-air warming blankets, reduces incidence of inadvertent perioperative hypothermia (IPH). Design Intervention study using retrospective chart review. Methods Patients received a preoperative forced-air warming blanket and temperature management with the normothermia bundle. Temperature status data was collected from patient charts to evaluate the incidences of IPH and findings from this data analysis was used to measure improvement in perioperative temperature management. Findings Of 200 patients, 63 (31.5%) remained normothermic, 37 (18.5%) had at least one documented hypothermic temperature, and 100 (50%) had no documented temperature during the intraoperative phase of care. Although compliance with intraoperative temperature monitoring decreased by 13% postintervention, the incidence of documented IPH in reviewed records was decreased by 3.6-fold. Conclusion Implementing a normothermia bundle that includes a preoperative forced-air warming blanket may lower the incidences of IPH, especially in surgical cases lasting over 120 minutes.

Hypothermia is a common and serious complication of spinal surgery and it is associated with many harmful perioperative outcomes. The aim of this study was to compare the effectiveness of warming blankets and warm fluid therapy to manage shivering. A quasi-experiment with a non-equivalent control group was applied as the research design. There were 60 patients involved in the study. The instrument of this study was a warmer fluid modification, a warming blanket and a cotton blanket. The data was analyzed using an applied paired t-test and independent t-test. After 60 minutes of the intervention, the mean and SD of body temperature of the patients receiving warm fluids was 36.71 ± 0.18, a warming blanket was 36.12 ± 0.35, and the control group was 35.76 ± 0.22. The p values were 0,000. Warm fluid therapy and warming blankets are significant in terms of increasing the body temperature of post-spinal anesthesia patients. Warm fluids are more effective than warming blanket. Warming blankets and warm fluid therapy can be used as a way to increase the body temperature of patients with hypothermia.

Background Prolonged extrication of entrapped patients after road traffic accidents increases the risk of sustained hypothermia. Accident-related hypothermia increases mortality in severely injured patients, and prehospital efforts to prevent hypothermia are essential. We evaluated various warming measures regarding their preclinical suitability and efficacy for patient warming, tested in realistically-simulated road traffic accident scenarios under cold ambient conditions in a climate chamber. Methods The effects of a chemical warming blanket (CWB), forced-air warming (FAW) device, or infrared radiator (IRR) on the core body and skin surface temperature of a subject previously exposed to a cold environment (5°C for 12 minutes) was recorded via temperature sensors and thermographically, respectively. Physiological parameters such as oxygen saturation, blood pressure, and heart rate were also monitored. Results Under cold environmental conditions, all devices were able to compensate or overcompensate the cooling of body parts directly exposed to the heating measure. In the body areas that were not directly warmed (back, lower extremities), only the CWB limited further cooling. FAW and IR irradiation rapidly and effectively warmed the heat-exposed areas (head and arms). However, both methods – but especially the IRR – led to a noticeably accelerated cooling in body parts not directly exposed to heat (back, legs). Conclusion The increased mortality associated with hypothermia in severely injured crash victims during prolonged vehicle extrication has intensified efforts to prevent sustained hypothermia. The use of a CWB, FAW or IRR are in principle all suitable for reducing or compensating for heat loss. The ongoing cooling of those body parts not directly exposed to the heat source was interpreted as a steal phenomenon in regional blood flow. However, the practicality and effectiveness of these measures, combined with their logistical requirements, must be evaluated in real extrication scenarios.

Background: A recent publication in the Journal of Trauma and Acute Care Surgery reported that patients who received a tourniquet (TQ) for severe extremity bleeding had a fourfold decrease in overall shock related mortality (Scerbo et al., 2017). A systematic review conducted in the United States (US) by Beaucreux, Vivian, Miles, Sylvain, and Pasquier (2018) showed that tourniquets are an effective tool for haemorrhage control in civilian populations with low levels of associated complications. Not a lot is known about the attitudes of Australian paramedics toward TQ’s or their use thereof, but anecdotal evidence suggests that their use is contentious. Case: We present a case of severe extremity haemorrhage involving a 90-year-old male who sustained a partial amputation to the lower aspect of the left leg proximal to the ankle whilst cutting a tree branch with a 5-inch toothed garden saw. Conclusion: In this case, the paramedics who attended to this patient believed that the use of a TQ was extreme. Standard trauma management and haemorrhage control measures that included a pressure bandage, vacuum splint and warming blanket served as confounding factors in obscuring an ongoing insidious bleed. Based on the injury profile, the patients advanced age, medications for comorbidities and associated decrease in physiological reserves this patient was a candidate for early TQ application. Failure to apply a TQ may have contributed to coagulopathy and the need for postoperative transfusions. Keywords: paramedics; bleeding; haemorrhage control; tourniquet.

Objective To assess the performance of an active patient-warming device. Materials and methods Temperatures of an active patient-warming device (HotDog system) were measured at various time points using an infrared thermometer. The study was conducted in two phases: Phase 1 compared temperatures among four different areas of the warming blanket. Phase 2 compared conditions simulating different scenarios using a weighted patient simulator. Results Phase 1: Three out of four positions on the warming blanket had significantly different temperature measurements. Phase 2: Temperature output by the warming blanket was reduced: (1) in the absence of the patient simulator placed across the blanket (-1·9°C, P=0·013); (2) if the patient simulator was placed away from the blanket sensor (-2·0°C, P=0·009); and (3) if there was fluid between the patient simulator and warming blanket (-2·2°C, P=0·004). In a majority of measurements (95%), the set temperature of 43°C on the control unit was not reached (range, 29·8 to 42·9°C) and 2·3% of measurements were higher (range, 43·1 to 45·8°C) than the control unit set temperature of 43°C. Clinical significance Measured temperatures on the active warming blanket did not reflect control unit settings. This could result in the potential for hyperthermic injury, ineffectual heating and uneven heat distribution.

The concentration and distribution of bacteria-carrying particles (BCPs) in the operating room have an important influence on surgical site infections (SSIs). Local heating is commonly used during surgery to reduce the incidence of perioperative hypothermia (PH). However, the effects of local heating measures on airflow and BCPs have not been thoroughly studied. In order to study the effect of local heating in the operating room on airflow and BCPs, the experiment was carried out in the standard experimental operating room using Bacillus subtilis, and CFD numerical simulation was carried out using k-e turbulence model and Lagrange particle tracking model. The distribution of airflow and the concentration of BCPs in the operating room was studied in the four cases of no local heating (case 1), heating pad (case 2), warming blanket (case 3), and both heating pad and warming blanket (case 4). The results showed that local heating reduced the airflow rate above the patient's body, which also led to an increase in the concentration of BCPs. At T = 300 s, the concentration of BCPs above the operating table in Case 2, Case 3, and Case 4 was increased by 600 CFU/m3 and 260 CFU/m3 and 670 CFU/m3, respectively, compared with that without local heating. As time goes on, the increment of the concentration of BCPs caused by local heating decreases. It is recommended to use heating pad to keep patients warm from less influence on the concentration of BCPs and airflow distribution. This study provides a reference for reducing patients' SSIs and provides a basis for insulation methods.

In electrocardiography, an electrocardiographic (ECG) artefact is used to indicate a misleading or confusing alteration in data or observation not arising from the heart. Although technological advancements have produced monitors that may provide accurate data and reliable heart rate alarms, interferences of the displayed electrocardiogram such as (but not limited to) electrical interference by outside sources, electrical noise from elsewhere in the body, poor contact and machine malfunction continue to occur. Artefacts are extremely common, and knowledge regarding them is necessary to prevent misinterpretation of a heart’s rhythm, which can often lead to unnecessary and unwarranted diagnostic and interventional procedures. Here we report a case of ECG artefacts that occur owing to a patient’s warming blanket and its consequences.

IntroductionActively warming hypothermic patients or preventing hypothermia is critical in optimising outcomes in patients with traumatic injuries. Our aim was to investigate the effect of ambient oxygen concentration on the rate and change in temperature of the TechTrade Ready-Heat II exothermic (oxygen-activated) warming blanket, to evaluate safety and ascertain the risk of thermal injury.MethodsA mannequin covered with an exothermic blanket was placed in a sealed oxygen tent. An ambulance blanket was placed between the TechTrade Ready-Heat II exothermic blanket and the mannequin. Two temperature probes were placed directly on the surface of the mannequin; one on the torso away from the heating packs and the other directly beneath the exothermic heating pack. The mannequin was exposed to increasing oxygen concentrations at 10% increments, starting at 21%. The experiment was conducted nine times, each time using a new blanket. Maximum temperature of the mannequin ‘skin’ and rate of rise were recorded from both temperature sensors.ResultsIn room air (21% oxygen), the mannequin surface reached 52°C after 60 min, matching manufacturer specifications. At 30% oxygen concentration, the temperature directly beneath the exothermic heating pack exceeded the 65°C threshold at which rapid thermal burns occur, reaching 72.5°C, with minimal change in overall torso temperature.ConclusionThe supplemental use of oxygen in patients with traumatic injuries that increases ambient oxygen levels in the presence of exothermic warming devices may represent a significant risk to the patient. We suggest that prehospital care providers remain highly vigilant of heat when using high-flow oxygen and the subsequent fire risk, while manufacturers of exothermic blankets should consider ways to improve safety.

Background: During head and neck surgery including orthognathic surgery, mild intraoperative hypothermia occurs frequently. Hypothermia is associated with postanesthetic shivering, which may increase the risk of other postoperative complications. To improve intraoperative thermoregulation, devices such as forced-air warming blankets can be applied. This study aimed to evaluate the effect of supplemental forced-air warming blankets in preventing postanesthetic shivering. Methods: This retrospective study included 113 patients who underwent orthognathic surgery between March and September 2015. According to the active warming method utilized during surgery, patients were divided into two groups: Group W (n = 55), circulating-water mattress; and Group F (n = 58), circulating-water mattress and forced-air warming blanket. Surgical notes and anesthesia and recovery room records were evaluated. Results: Initial axillary temperatures did not significantly differ between groups (Group W = 35.9 ± 0.7°C, Group F = 35.8 ± 0.6°C). However, at the end of surgery, the temperatures in Group W were significantly lower than those in Group F (35.2 ± 0.5°C and 36.2 ± 0.5°C, respectively, P = 0.04). The average body temperatures in Groups W and F were, respectively, 35.9 ± 0.5°C and 36.2 ± 0.5°C (P = 0.0001). In Group W, 24 patients (43.6%) experienced postanesthetic shivering, while in Group F, only 12 (20.7%) patients required treatment for postanesthetic shivering (P = 0.009, odds ratio = 0.333, 95% confidence interval: 0.147–0.772). Conclusions: Additional use of forced-air warming blankets in orthognathic surgery was superior in maintaining normothermia and reduced the incidence of postanesthetic shivering.

Introduction Maintaining normothermia during anesthesia is imperative to provide quality patient care and to prevent adverse outcomes. Prolonged laparoscopic procedures have been identified as a potential risk factor for hypothermia, due to continuous insufflation of cold and dry carbon dioxide. Perioperative hypothermia is associated with increased hospital cost and many complications including; impaired drug metabolism, impaired immune function, cardiac morbidity, shivering, coagulopathy. Methods In this experimental study, four pigs underwent four interventions each, resulting in 16 total trials. Using standardized general anesthesia in a randomized Latin-square sequence the four interventions include: 1. Control group without an administered pneumoperitoneum, 2. Administered standard pneumoperitoneum using 21°C insufflated gas and under-body forced-air warming, 3. Administered pneumoperitoneum with insufflation of warmed/humidified carbon dioxide, 4. Administered pneumoperitoneum with insufflation of warmed/humidified carbon dioxide and under-body forced-air warming. The primary outcome was distal esophageal temperature change 4 hours after trocar insertion. Results Four hours after trocar insertion, pigs in the control group lost 2.1 ± 0.4°C; pigs with warmed and humidified insufflation lost 1.8 ± 0.4°C; pigs with forced-air warming group lost 1.3 ± 0.9°C; and pigs exposed to a combination of warmed and humidified insufflation with forced-air warming increased by 0.3 ± 0.2°C. Conclusion This experimental animal study provides evidence that a combination of warmed and humidified insufflation of carbon dioxide (CO2) in conjunction with forced-air warming is an effective strategy in the prevention of perioperative hypothermia. Further clinical trials investigating humans are therefore indicated.

The four arm study investigates how use of a preoperative forced-air warming blanket and adjustment of ambient surgical room temperature may contribute to prevention of perioperative hypothermia. Active warming interventions may prevent the drop in core temperature that occur as a result of surgical anesthesia. Core body temperatures from a convenience sample of 220 adult surgical patients were sequentially monitored in the preoperative, intraoperative, and post-anesthesia care units (PACU) while receiving: (a) routine surgical care, (b) application of preoperative forced-air warming blanket, (c) application of preoperative forced-air warming blanket with adjustment of ambient surgical room temperatures, or (d) adjustment of ambient surgical room temperature only. Sample characteristics were evenly distributed among the four groups. There were no statistical differences in PACU core body temperatures. The application of forced-air warming blankets and room temperature adjustment interventions were not more effective than current practice in preventing perioperative hypothermia.

The purpose of this randomized clinical trial was to compare the efficacy of three patient warming devices (i.e., circulating water blanket, forced-air, and warming panels) used either alone or in combination on patients undergoing surgeries lasting >60 min. In total, 238 dogs were included and divided into either the celiotomy or nonceliotomy group. Dogs in each group were further divided into one of three subgroups. Dogs in subgroup 1 (n=39) were placed on a circulating water blanket with a forced-air warming blanket placed over the trunk. Subgroup 2 dogs (n=40) were placed on a forced-air warming blanket only. Subgroup 3 dogs (n=40) were placed on warming panels. Significant temperature drops occurred from time of induction (38.1°C±0.64°C) to the start of surgical procedures (36.7°C±0.95°C). Although body temperature was maintained once the warming units were started in all groups, there were significant differences in temperatures for the type of surgical procedures (i.e., celiotomies versus nonceliotomies) performed over time except for subgroup 3. The warming panels and forced-air devices were equally effective in preserving body temperature in anesthetized patients.

The ability to maintain normothermia during surgical procedures is crucial for improvement of the quality of patient care and the outcome of the procedure. We tested the hypothesis of whether one warming protocol is able to maintain normothermic core temperatures equally well in major open and laparoscopic urologic procedures.In this prospective study, 300 patients who were scheduled for open (n=53) or laparoscopic (n=247) urologic procedures were included and received intraoperative warming using a combination of an upper and lower body forced-air warmer and a single warming blanket. Core temperature was measured at baseline, at induction of anesthesia, at the start of the operation, and at the end of the operation.A significant improvement in core temperature during the operation was achieved in all patients (P0.001). There was no difference in the end-of-operation core temperature between laparoscopic and open procedures: (36.29 degrees C+/-0.03 degrees C v 36.23 degrees C+/-0.06 degrees C; P=0.224). Further, 23.3% of all patients had a core temperature of lower than 36.0 degrees C at the end of the operation (laparoscopy 23.8% v open 26.6%). Linear regression analysis revealed a correlation between duration of the operation and intraoperative core temperature (P0.001).The present warming protocol is effective in maintaining perioperative normothermia during major open and laparoscopic urologic procedures.

SummaryBackground Postoperative hypothermia in the postanesthesia care unit (PACU) in neonates and infants is a well-known serious complication as it can increase the risk of blood loss, wound infections, and cardiac arrhythmias. Aim To identify an effective rewarming method for neonates and infants in China with postoperative hypothermia, an open-label, randomized, and controlled study was performed to compare the effects of three different rewarming methods. Methods Neonates and infants (

Four geosynthetic reinforced soil (GRS) piers were constructed in 2012 to support two decommissioned 25.9 m concrete I-girders at the Federal highway Administration's (FHWA’s) Turner-Fairbank Highway Research Center in McLean, Virginia. Two of the GRS piers are built with an American Association of State Highway and Transportation Officials (AASHTO) No. 8 open-graded aggregate while two are built with an AASHTO A-1-a well-graded aggregate. Survey targets, strain gages, and pressure cells were installed on and in the piers to evaluate long term performance. Through these monitoring efforts, it was discovered that the piers with the well-graded aggregate behaved differently and experienced increased settlement after the first winter cycle. To investigate this further, one of these piers was wrapped with a warming blanket set to turn on when the ambient temperature drops to 1°C to ensure the system remained above freezing. In addition, slide wire potentiometers were installed to monitor the thermal movement of both the I-girders and the face of the walls. The relative movement between the face and the beam provides insight into the super-substructure interaction for GRS. As with the increased settlement for well-graded aggregates during thermal cycles, there is also thermal movement impacting performance. The use of well-graded backfill with any appreciable fine content, regardless of plasticity, may result in thaw weakening and increased movements. Observations also indicate that the I-girders and GRS piers move together. This paper will describe the testing, present results, and provide recommendations on the use of well-graded backfills for GRS piers.

This report reviews the use of the Cool-Cap device to apply selective therapeutic hypothermia to the brain of preterm infants, without causing systemic hypothermia. Four infants, 32-35 weeks gestation, with suspected Hypoxic Ischemic Encephalopathy (HIE) received treatment aimed at providing selective brain cooling. It was not possible to apply cold circulat- ing water to the scalp of the preterm infant without systemic hypothermia unless a warming blanket was also used. All infants had severe HIE and all had either death, or neurologic disability despite cooling attempts. Therapeutic hypothermia cannot be recommended at this time for preterm infants outside clinical trials.

Background: Fiberoptic light sources have been identified as a fire ignition mechanism in the operating room. This study attempted to determine whether a forced-air warming blanket (FAWB) could affect the ignition or spread of fire caused by a fiberoptic light source. Methods: We exposed surgical drapes to a fiberoptic light source at close range. The results were categorized according to time to first smoke and damage resulting at 1 min. Data were analyzed using the Mann–Whitney rank-sum test. Results: The sums of the rank values for the components of the drape indicated that there was a greater than 96.8–99.2% chance that the FAWB accelerated the time to first smoke. The FAWB appeared to protect the patient gown from damage during all trials. The presence of an FAWB under a surgical drape accelerated the time to first smoke when exposed to unprotected fiberoptic light sources, yet prevented damage to the underlying patient gown. In an actual surgical setting, it is likely that the FAWB would offer some protection to the patient's skin directly below the surgical drape. Conclusion: It is likely that the FAWB can offer some protection to the patient should an unprotected fiberoptic light source cause a fire.

After an uneventful caesarean delivery under spinal anaesthesia (hyperbaric bupivacaine 10mg, sufentanil 5μg and morphine 50μg), hypothermia (nadir 34°C) was recorded in a ASA 1 patient. Partial recovery was rapidly obtained with 400μg of naloxone but full recovery was obtained after seven hours of active rewarming with a forced-air warming blanket. Suggested pathophysiology and incidence of this hypothermia are described.

＊＊＊ , member The brain hypothermia treatment is an attractive therapy for the neurologist because of its neuroprotection in hypoxic-ischemic encephalopathy patients. The present paper deals with the possibility of controlling the brain and other viscera in different temperatures from the viewpoint of system control. It is theoretically attempted to realize the special brain hypothermia treatment to cool only the head but to warm the body by using the simple apparatus such as the cooling cap, muffler and warming blanket. For this purpose, a biothermal system concerning the temperature difference between the brain and the other thoracico-abdominal viscus is synthesized from the biothermal model of hypothermic patient. The output controllability and the asymptotic stability of the system are examined on the basis of its structure. Then, the maximum temperature difference to be realized is shown dependent on the temperature range of the apparatus and also on the maximum gain determined from the coefficient matrices A, B and C of the biothermal system. Its theoretical analysis shows the realization of difference of about 2.5℃, if there is absolutely no constraint of the temperatures of the cooling cap, muffler and blanket. It is, however, physically unavailable. Those are shown by simulation example of the optimal brain temperature regulation using a standard adult database. It is thus concluded that the surface cooling and warming apparatus do no make it possible to realize the special brain hypothermia treatment, because the brain temperature cannot be cooled lower than those of other viscera in an appropriate temperature environment. This study shows that the ever-proposed good method of clinical treatment is in principle impossible in the actual brain hypothermia treatment.

Background and Aims: Unintended hypothermia (UIH) during surgery under general anaesthesia has adverse implications. A retrospective analysis of the perioperative temperature records of healthy voluntary liver donors was done to evaluate the efficacy of a multimodal protocol for temperature management. Methods: Records of 50 American Society of Anesthesiologists physical status Class 1 patients operated for Donor Hepatectomy lasting >2 h under combined general and epidural anaesthesia were analysed. Ambient temperature was maintained 24°C–27°C before induction of GA and during insertion of epidural catheter. Active warming was done using warming mattress set to temperature 38°C, hot air blanket with temperature set to 38°C and fluid warming device (Hotline™) with preset temperature of 41°C. Nasopharyngeal temperature was continuously monitored. After induction of GA and draping of the patient, ambient temperature was decreased and maintained at 21°C–24°C and was again increased to 24°C–27°C at the conclusion of surgery. During surgery, for every 0.1°C above 37°C, one heating device was switched off such that at 37.3°C all the 3 devices were switched off. Irrigation fluid was pre-warmed to 39°C. Results: Baseline temperature was 35.9°C ± 0.4°C. Minimum temperature recorded was 35.7°C ± 0.4°C. Mean decrease in temperature below the baseline temperature was 0.2°C ± 0.2°C. Temperature at the end of surgery was 37.4°C ± 0.5°C. Conclusion: Protocol-based temperature management with simultaneous use of resistive heating mattress, forced-air warming blanket, and fluid warmer along with ambient temperature management is an effective method to prevent unintended perioperative variation in body temperature.

REVIEW QUESTION / OBJECTIVE The objective of this systematic review is to synthesize the best available evidence comparing forced air warming devices to other active warming devices to determine whether or not there is an increased risk of surgical site contamination by microbial emissions during the perioperative period. Specifically the review question is: Do forced air warming devices compared to other active warming devices have an increased risk of surgical site contamination during the perioperative period? INCLUSION CRITERIA Types of participants This review will consider studies that include subjects (patients, volunteers, mannequins) of all ages that were warmed perioperatively in any type of surgery or simulated surgical environment. Types of intervention(s) This review will consider studies that compare only forced air warming devices to other active warming technologies such as a radiant warming blanket. Types of outcomes This review will consider studies that include the following outcome measures: particle counts or neutrally buoyant bubble counts, measured by: a laser particle count device or time-lapse photography.

Laboratory experiments were performed to determine warming rates of albumin 5% at room temperature and human packed red blood cells (PRBCs) at 4 degrees C in small volumes. Four methods used in clinical practice to warm volumes appropriate for neonates were studied.The fluids were warmed either by infusion through a fluid warmer with temperature-controlled coaxial tubing (Group I), immersion in a water bath at 37 degrees C (Group II), placing pre-filled syringes (10 and 20 ml) between a circulating water mattress and a forced-air warming blanket (Group III), or placing the same syringes between the water mattress and cotton towels (Group IV). The temperature of each fluid was recorded for the next 60 sec after the bolus injection in group I and every five minutes for a total of 30 min for the other groups. The time constant of warming for each group was calculated. The time constant and the temperature reached after the warming period were compared among groups.In group I 20 ml room temperature albumin 5% or 4 degrees C blood reached temperatures of 36.9 +/- 1.5 degrees C and 34.5 +/- 2.3 degrees C within 60 sec, respectively. This was faster than all other techniques used (P0.001). The time constants measured for the albumin and the PRBCs were 0.23 +/- 0.1 and 0.20 +/- 0.05 minutes respectively. After 15 min albumin and PRBCs in group II reached 35.5 +/- 0.4 degrees C and 33.4 +/- 0.3 degrees C, in group III reached 33.7 +/- 1.0 C and 32.8 +/- 1.7 C, and in group IV reached 29.5 +/- 0.1 degrees C and 23.3 +/- 0.8 degrees C after 15 min respectively.Warming of intravenous fluids in small volumes is accomplished most rapidly using a fluid warmer with temperature-controlled coaxial tubing and occurs more slowly in syringes, bottles, or bags exposed to various environmental conditions.

Hypothermia is a common complication in patients undergoing surgery under general anesthesia. It has been noted that, during the first hour of surgery, the patient’s internal temperature (Tcore) decreases by 0.5–1.5°C due to the vasodilatory effect of anesthetic gases, which affect the body’s thermoregulatory system by inhibiting vasoconstriction. Thus a continuous check on patient temperature must be carried out. The currently most used methods to avoid hypothermia are based on passive systems (such as blankets reducing body heat loss) and on active ones (thermal blankets, electric or hot-water mattresses, forced hot air, warming lamps, etc.). Within a broader research upon the environmental conditions, pollution, heat stress, and hypothermia risk in operating theatres, the authors set up an experimental investigation by using a warming blanket chosen from several types on sale. Their aim was to identify times and ways the human body reacts to the heat flowing from the blanket and the blanket’s effect on the average temperatureTskinand, as a consequence, onTcoretemperature of the patient. The here proposed methodology could allow surgeons to fix in advance the thermal power to supply through a warming blanket for reaching, in a prescribed time, the desired body temperature starting from a given state of hypothermia.

Objective: The purpose of this study was to identify risk factors contributing to pressure ulcer development in patients undergoing scheduled, prolonged operative procedures. Design: A descriptive study was conducted. Setting and subjects: A large university teaching facility provided the setting. Thirty-three subjects who underwent operative procedures lasting longer than 10 hours, as determined from the daily operating room schedule through a 6-month period, were included in the study. Instruments: Braden Scale for Predicting Pressure Sore Risk was used before the operation. Visual skin inspection, preoperative interventions, and demographic information were documented with a data-collection tool. Postoperative skin breakdown and its severity were assessed as stage I through IV according to the Pressure Ulcer Classification System recommended by the National Pressure Ulcer Advisory Panel. Methods: Visual preoperative skin assessment was performed and the Braden Scale was completed in the operating room holding area. Demographic information was collected from patient interviews and the medical record. Patient positioning and the placement of all positioning and thermal devices were observed and recorded in the operating room. Within 48 hours after the surgical procedure, the patients' skin was visually inspected. Pressure ulcers were noted, staged, and recorded. Main outcome measures: The χ2 analyses compared those who did and those who did not acquire pressure ulcers for differences in gender, type of operation, position used in the operating room, and types of positioning devices. Student's t tests compared those who did and did not acquire pressure ulcers for differences in age. Braden Scale score, number of positioning devices, and length of operation. Results: Of the 33 patients studied, 15 (45%) were found to acquire stage I or II pressure ulcers within 48 hours after their procedure. Of the 15 patients who acquired pressure ulcers, 75% were placed on a warming blanket during the procedure. This was the only significant finding among the risk factors investigated in the comparison of those who did and did not acquire pressure ulcers (χ2 = 4.3, p < 0.05). Conclusions: Removal of the warming blanket from routine intraoperative use with patients undergoing prolonged operations is indicated. Continued follow-up of this patient population will help to determine whether avoidance of warming blankets is sufficient to lower the incidence of pressure ulcer formation.

A case of hypothermia occurring during laparoscopic nephrectomy for kidney donation is presented. Induction of general anesthesia and multiple boluses of unwarmed normal saline precipitated the drop in temperature which decreased to 33.6 °C during the case. Following the placement of a forced-air warming blanket and fluid warmers, the patient’s temperature improved and eventually normalized in the postanesthesia care unit (PACU). Expected changes in temperature following the induction of general anesthesia are reviewed. The initial decrease in core body temperature is caused by a redistribution of blood from the patient’s core to periphery. This is followed by continued heat loss to the environment via four main processes: radiation, convection, conduction, and evaporation. Multiple deleterious consequences of hypothermia are discussed which include myocardial ischemia, cardiac dysrhythmias, altered metabolism of drugs, and increased PACU stay. Lastly important methods to warm a hypothermic patient are summarized.

Normothermia during off-pump coronary bypass (OPCAB) grafting reduces metabolic derangements and contributes to improved clinical outcomes. Thus study examined the feasibility and efficacy of intraoperative temperature control using a novel endovascular heating system during OPCAB.Thirty-eight consecutive patients undergoing OPCAB were prospectively randomized to receive conventional warming (elevated room temperature, warmed intravenous fluids, warming blanket) or the Thermogard system (Alsius Corp, Irvine, CA). The triple-lumen temperature control Icy catheter (Alsius Corp) was inserted percutaneously into the inferior vena cava through common femoral vein. The catheter was removed after all wounds were closed. Temperature measurements (bladder, nasopharyngeal, and blood) were recorded at 5-minute intervals and compared between groups.Patient demographics did not significantly differ between groups. The 17 Thermogard patients warmed at a significantly faster rate than the 21 control patients (0.28 degrees vs 0.11 degrees C/h, p = 0.03). Furthermore, Thermogard patients received more bypass grafts (3.4 +/- 0.6 vs 2.6 +/- 0.9, p0.001) and less intraoperative fluids (1557.0 +/- 547.7 vs 2012.3 +/- 723.1 mL, p = 0.02) despite longer operative times (150.3 +/- 123.4 vs 108.1 +/- 43.7 min; p = 0.12). All catheters were placed successfully on the first attempt, and there were no device-related complications.Endovascular warming is safe, simple to use, and obviates the need for uncomfortably warm operating room temperatures. The Thermogard system compared favorably with conventional methods for warming during OPCAB.

Summary Background: Forced-air warming systems have proven effective in preventing perioperative hypothermia. To date, reported adverse events relate primarily to overheating and thermal injuries. This study uses a simple model to show that forced-air warming blankets become ineffective if they get wet. Methods: Temperature sensor probes were inserted into three 1-liter fluid bags. Group C bags served as the control. Groups D (dry) and W (wet) bags were placed on Bair Hugger® Model 555 (Arizant Healthcare, Inc., Eden Prairie, MN, USA) pediatric underbody blankets. The warming blanket for Group W bags was subsequently wet with irrigation fluid. Temperature was documented every 5 min. This model was repeated two times for a total of three cycles. Statistical analysis was performed using anova for repeated measures. Results: Starting temperatures for each model were within a 0.3°C range. Group C demonstrated a steady decline in temperature. Group D maintained and slightly increased in temperature during the observation period, while Group W exhibited a decrease in temperature at a rate similar to Group C. These results were significant at P

OBJECTIVE We evaluated the performance of a new temperature management system (Arctic Sun, Medivance, Inc.) in maintaining normothermia during off-pump coronary artery bypass (OPCAB). PATIENTS AND METHODS Ninety-eight unselected patients were prospectively randomized to either a conventional temperature management method (consisting of a sterile forced-air warming blanket, warm intravenous fluids, and maintenance of a warm OR) or the new Arctic Sun system (two pads, Arctic Sun Energy Transfer Pads placed on the patient's back with temperature-controlled water flowing through the pads). RESULTS The mean age, body surface area, and total operating time were similar in both groups. Despite significantly lower room temperatures (p

Critically injured patients are at risk for hypothermia. This study determined the efficacy of three hypothermia prevention strategies: the ChillBuster warming blanket, ChillBuster with a reflective blanket, and two wool blankets. A quasi-experimental design was used to compare changes in core temperature. Following resuscitation from hypovolemic shock, 20 swine were assigned to one of the three interventions, placed in an environmental chamber set to reproduce in-flight conditions onboard a military cargo aircraft (50 degrees F/airspeed 0.2 m/s), and monitored for 6 hours. A repeated measures analysis of variance and least-squared difference post hoc were performed. The ChillBuster/reflective blanket group was significantly warmer than the ChillBuster only group and the wool blanket group (p0.01). After 6 hours of cold exposure, the ChillBuster/reflective blanket group remained warm while the ChillBuster only and wool blanket groups developed mild hypothermia. Combined use of a warming blanket and reflective blanket was effective in preventing hypothermia over 6 hours and is feasible in a deployed military environment.

UNLABELLED Upper abdominal pain, a frequent symptom of the presence of gallstone disease, is the cause of 6% of the emergency calls of the Austrian emergency system. Pain resulting from cholelithiasis is characteristically severe. Recent data show that active warming during emergency transport of trauma victims is effective in reducing pain. Therefore, we hypothesized that local active warming of the abdomen would be an effective pain treatment for patients with acute cholelithiasis and could be provided by paramedics. Sixty patients (>19 yr) consented to participate in this study. They were divided into two groups: Group 1, who received active warming of the upper abdomen with a carbon-fiber warming blanket (42 degrees C), and Group 2, who received no warming of the abdomen. Neither group received any drug-based pain care. Patients were asked to rate their pain and anxiety by using visual analog scales (VAS). Statistical evaluation was performed with Student's t-test; P < 0.05 was considered significant. In Group 1, a significant (P < 0.01) pain reduction was recorded in all cases on a visual analog scale (VAS), from 86.8 +/- 5.5 mm to 41.2 +/- 16.2 mm. In Group 2, the patients' pain scores remained comparable, from 88.3 +/- 9.9 mm to 88.1 +/- 10.0 mm on a VAS. In comparing Group 1 with Group 2 on arrival at the hospital, pain scores showed a significant difference (P < 0.01). In Group 1, the VAS score changes for anxiety were significantly reduced (P < 0.01), from 82.7 +/- 10.8 mm before treatment to 39.0 +/- 14.0 mm after treatment. In Group 2, a nonsignificant change of this score was noted, from 84.5 +/- 14.6 mm to 83.5 +/- 8.4 mm. Comparing Group 1 with Group 2 on arrival at the hospital showed a significant difference in anxiety scores (P < 0.01). We conclude that local active warming is an effective and easy-to-learn treatment for pain resulting from acute cholelithiasis in emergency care. IMPLICATIONS Active local warming of the upper abdomen is an effective treatment for patients with cholelithiasis being transported to the hospital by paramedics who are not permitted to provide any drug-based pain care. We observed no negative side effects of this treatment.

To introduce a reusable model of neonatal forced air warming blanket for intraoperative use during major noncardiac neonatal surgery and to determine clinical efficacy of this reusable blanket compared with the commonly used disposable blankets.Delivered air temperature and calorie uptake of standard thermal bodies within the reusable blankets, Bair Hugger(R) blanket model 530 and model 555 were studied. Also, an efficacy study was conducted in 90 neonatal patients scheduled for major noncardiac surgery comparing the reusable blanket, the Bair Hugger(R) blanket model 530 and passive heat conservation as a control. The covered reusable blanket was used as a rescue procedure if the core temperature was35.5 degrees C.Delivered air temperature and heat transfer from the covered reusable blanket did not differ significantly from those of the Bair Hugger(R) blanket model 530 and model 555 (despite 0.75 degrees C-1.2 degrees C of heat trapped under the sheet and 1.3 Kcal less energy transfer). Temperatures measured underneath patients (correlated to poorly perfused areas) were highest using the Bair Hugger(R) blanket model 555. The reusable blanket was efficacious in preventing intraoperative core hypothermia and not different from the Bair Hugger(R) blanket model 530. About 1/3 of the patients in the control group had presented a core temperature35.5 degrees C but were successfully rescued using the reusable blanket. No adverse events were associated with any of these warming methods.This study shows the clinical efficacy of our reusable blanket for the prevention of core hypothermia during major neonatal surgery, which is not different from commonly used disposable blankets.

IMPLICATIONS This case describes the narcotic overdose associated with the use of a fentanyl transdermal patch in a patient being rewarmed with an external warming blanket during surgery. The clinical manifestation and the presumed pharmacokinetic mechanism responsible for the fentanyl overdose are discussed.

We have compared the Thermomat electric undermattress (JMW Systems, Edinburgh, UK) and the Bair Hugger (Augustine Medical, Courtelary, Switzerland) forced-air warming blanket in 30 adult patients after cardiac surgery. All patients were warmed to an oesophageal temperature of 38 degrees C before termination of cardiopulmonary bypass (CPB); those with oesophageal temperatures35.5 degrees C at skin closure were allocated randomly to be rewarmed in the intensive care unit either on the Thermomat (n = 15) or under the Bair Hugger blanket (n = 15), at their highest settings. Oesophageal and lateral thigh skin temperatures were recorded every 15 min for 4 h. There was a significantly faster increase in core temperature (0.5 vs 0.75 degrees C h-1; P0.0002) and skin temperature (0.86 vs 1.3 degrees C h-1; P0.001) in the Bair Hugger group. However, there was no difference in the number of patients who reached a core temperature of 36 degrees C (15 Bair Hugger, 14 Thermomat) or 37 degrees C (11 Bair Hugger, seven Thermomat), or in the number of patients who reached a skin temperature of 37 degrees C in 4 h (four Bair Hugger, one Thermomat). Twelve patients in the Bair Hugger group reached a skin temperature of 36 degrees C compared with two in the Thermomat group (P0.001). The Bair Hugger warmed faster than the Thermomat both centrally and peripherally, and warmed more patients to a core temperature of 37 degrees C in 4 h, but did not reduce the time to tracheal extubation or alter important clinical aspects of postoperative course.

s, 7th International Conference of the Hospital Infection Society, 10–13 October 2010, Liverpool, UK / Journal of Hospital Infection 76S1 (2010) S1–S90 S39 increased. Nevertheless, its reliability has to be demonstrated yet before proposing to substitute microbiological sampling. Objective: To study whether particle counting could be predictive of microbiological contamination of air in operating rooms. Methods: From January 21 to April 21 2010, particle counting and microbiological air sampling were performed in 22 operating rooms in a 1300-bed university hospital. Microbiological air counts were measured using an air sampler which impacted on Sabouraud agar and Blood agar. Means of Particles were counted by a particle analyser for 1 min. Spearman correlation coefficient was used to analyze the association between particle counts and colony counts. Different values of CFU/m were chosen as critical values to create COR curves. We tried to find the best cut-off value of particle counting to obtain the best predictive value of microbiological contamination. Results: 32 microbiological samples and 96 particles counting were performed. Spearman correlation coefficients were: particle 0.3 mmbacterial r = 0.294 p=0.007, 0.5 mm-bacterial r = 0.107 p=0.333, 5 mm-bacterial r = 0.025 p=0.823, 0.3 mm-fungal r = 0.389 p 10,000 cfu/L. Among other wards, emergency medicine and oncology are the most contaminated (31% of positive samples). The worst year was 2008 with 75% of positive samples. Conclusion: Hospital water system seems to be affected by Legionella spp. colonization most frequently from 2006 to 2010. The high percentage of positivity in 2008 was related to the presence of a building yard in the hospital. In 2010 there was an improvement, although boilers, surgery, medicine and oncology are still contaminated. It is necessary now to investigate the temperature level mantained in hot-water system and also to observe if the structural characteristics of water ducts could have influenced the colonization observed. P11.23 Effect of forced-air warming (FAW) on operating theatre air quality: assessment using computer modeling and submicron particle release R. Olmsted, F. Memarzadeh, R. Kulpmann, B. Schlautmann. Saint Joseph Mercy Health System, United States; National Institutes of Health, United States; Beuth University of Applied Sciences, Germany; HYBETA GmbH, Germany Background: Perioperative hypothermia (PH) causes significant morbidity and increases risk of surgical site infection (SSI). Active warming devices are used to prevent PH. Forced-air warming (FAW) warms by convection by delivering air at 42°C. Some have asked whether FAW introduces contaminants into the surgical site or alters airflow in the operating theatre (OT). Aim(s)/Objective(s): Assess effect of FAW in the OT using two different analytical methods. Methods: Computational fluid dynamics (CFD) modeling of airborne particles was used to assess impact of FAW in an OT. Submicron particles were released in two different OTs. The OT had a human volunteer, two FAW models, and other standard equipment. Particle counts were quantified after release. A protective effect (PE) score based on German Deutsches Institut fur Normung (DIN) 1946–4:2008–12 was calculated. Smoke plume was used to visualize airflow in the OT with and without FAW. Results: CFD analysis found no deposition of particles on the patient with or without activation of the FAW device and minimal disruption of airflow. Smoke plume divided neatly above the patient, flowed to either side and downward below the OT table. No outflow from the warming blanket rose back into the surgical field. In all cases, PE score of 3.0–5.0, i.e. particle log reduction, was observed with or without the FAW activated which was well above the 2.0 threshold value indicated as minimum value by the DIN standard. Conclusion: CFD analysis did not find any deposition of particles onto the surgical site nor significant disruption of airflow in the OT with use of FAW. There was no compromise in the PE when FAW was activated. In fact, under conditions that reflect real operating conditions, the PE was significantly better than the minimal threshold values used to validate class Ia OT based on DIN standard. We find no objective evidence that FAW has any undesirable effect on air quality during intraoperative care. P11.24 Review of current evidence on the reduction of infection rates in ten NHS hospitals using the Inov8 AD (air disinfection) technology A. Ezbiri, R. Elen, J. Leech. Inov8 Science Ltd, United Kingdom; Sunlight Clinical Solutions, United Kingdom This paper is a first in a series of articles where we present a systematic review of available quantitative evidence on the correlation between bio-burden reduction in a hospital setting and the reduction in cross infections. We have conducted trials of Inov8 Air Disinfection Technology in various UK NHS Hospital Trusts (Hereford, Worcester and Redditch, Trafford, Huddersfield and Caulderdale, Shrewsbury, Northampton, North Staffordshire, Wolverhampton, Nottingham and the The Royal Free Hospital amongst others). These trials ran for periods of between three and seven months in duration. We have identified that the introduction of the AD technology has had a significant reduction effect on the level of bio-burden (between 40% and 90%). The hospitals’ own data suggests that, for at least part of the set, there is good correlation between the bio-burden reduction and the rates of outbreaks from Clostridium difficile, Norovirus and MRSA. The evidence presented in this article therefore proposes the following working hypothesis: The use of the Inov8 AD Technology in a hospital setting helps to significantly reduce the environmental

Perioperative hypothermia in coronary artery bypass graft (CABG) is associated with adverse outcomes [1,2]. An underbody forced-air warming blanket was developed for use in cardiac surgery. The primary aim of this investigation was to study whether this blanket could prevent postoperative hypothermia in routine CABG.

A study has been conducted on infants under six months of age during induction and anaesthesia to compare the effect on heat loss when a warming blanket, a humidifier and an overhead heater were used. The combination of all three was associated with significantly less heat loss than when the blanket was used alone. The particular benefit of the overhead heater during prolonged preparation for neurosurgery was also demonstrated. It is recommended that overhead heaters should be used during induction of anaesthesia in infants.