Body Blanket Research Articles

Effect of a Forced-Air Warming Blanket on Different Parts of the Body on Core Temperature of Patients Undergoing Elective Open Abdominal Surgery: A Randomized Controlled Single-Blind Trial

PurposeThis study aimed to determine the effect of a forced-air warming blanket placed on different body parts on the core temperature of patients undergoing elective open abdominal surgery. DesignProspective, single-center, randomized, controlled, single-blind trial. MethodsA total of 537 patients who underwent open abdominal surgery were randomized into groups A, B, and C and provided with different forced-air warming blankets. Group A was given an upper body blanket, group B a lower body blanket, and group C an underbody blanket. The incidence of intraoperative hypothermia, the time maintaining the core temperature over 36 ℃ before hypothermia, the duration of hypothermia, the rewarming rate, and relevant complications were compared among three groups. FindingsIntraoperative hypothermia occurred in 51.4% of patients in group B, 37.6% of patients in group A, and 34.1% of patients in group C (P = .002). Maintaining the core temperature above 36 ℃ was longer before hypothermia in groups A and C (log-rank P = .006). In groups A and C, the duration of hypothermia was shorter, the rewarming rate was higher, and the incidence of shivering and postoperative nausea and vomiting were lower, compared to group B. ConclusionsIn patients undergoing elective open abdominal surgery, a forced-air warming blanket on the upper body part or underbody area decreased intraoperative hypothermia, prolonged the time to maintain the core temperature above 36 ℃ before hypothermia, and could better prevent further hypothermia when the core temperature had decreased below 36 ℃. In addition, it was significantly superior in reducing shivering and postoperative nausea and vomiting in the postanesthesia care unit.

Thermal suit connected to a forced-air warming unit for preventing intraoperative hypothermia: A randomised controlled trial.

Inadvertent intraoperative hypothermia is a common occurrence in surgical patients. A thermal suit is an option for passive insulation. However, active warming is known to be more effective. Therefore, we hypothesised that a forced-air warming (FAW) unit connected to the thermal suit is superior to a commercial FAW blanket and a warming mattress in breast cancer surgery. Forty patients were randomised to this prospective, clinical trial to wear either the thermal suit or conventional hospital clothes under general anaesthesia. The Thermal suit group had a FAW unit set to 38°C and connected to the legs of the suit. The Hospital clothes group had a lower body blanket set to 38°C and a warming mattress set to 37°C. Core temperature was measured with zero-heat-flux sensor. The primary outcome was core temperature on admission to the recovery room. There was no difference in mean core temperatures at anaesthetic induction (P=.4) or on admission to the recovery room (P=.07). One patient in the Thermal suit group (5%) vs six patients in the Hospital clothes group (32%) suffered from intraoperative hypothermia (P=.04, 95% CI 1.9%-49%). Mean skin temperatures (MSTs) were higher in the Thermal suit group during anaesthesia. No burns or skin irritations were reported. Two patients in the Thermal suit group sweated. A thermal suit connected to a FAW unit was not superior to a commercial FAW blanket, although the incidence of intraoperative hypothermia was lower in patients treated with a thermal suit.

Intensified thermal management for patients undergoing transcatheter aortic valve implantation (TAVI)

BackgroundTranscatheter aortic valve implantation via the transapical approach (TAVI-TA) without cardiopulmonary bypass (CPB) is a minimally invasive alternative to open-heart valve replacement. Despite minimal exposure and extensive draping perioperative hypothermia still remains a problem.MethodsIn this observational study, we compared the effects of two methods of thermal management on the perioperative course of core temperature. The methods were standard thermal management (STM) with a circulating hot water blanket under the patient, forced-air warming with a lower body blanket and warmed infused fluids, and an intensified thermal management (ITM) with additional prewarming using forced-air in the pre-operative holding area on the awake patient.ResultsNineteen patients received STM and 20 were treated with ITM. On ICU admission, ITM-patients had a higher core temperature (36.4 ± 0.7°C vs. 35.5 ± 0.9°C, p = 0.001), required less time to achieve normothermia (median (IQR) in min: 0 (0-15) vs. 150 (0-300), p = 0.003) and a shorter period of ventilatory support (median (IQR) in min: 0 (0-0) vs. 246 (0-451), p = 0.001).ConclusionITM during TAVI-TA reduces the incidence of hypothermia and allows for faster recovery with less need of ventilatory support.

Intra-Operative Warming with a Forced-Air Warmer in Preventing Hypothermia after Tourniquet Deflation in Elderly Patients

This randomized, single-blind study aimed to explore the effects of intra-operative warming with a forced-air warmer in the prevention of hypothermia after tourniquet deflation in elderly patients undergoing unilateral total knee replacement arthroplasty under general anaesthesia. Patients were randomized to receive either intra-operative warming using a forced-air warmer with an upper body blanket (warming group; n = 12) or no intra-operative warming (nonwarming group; n = 12). Oesophageal temperature was measured as core body temperature. At 30 min following tourniquet inflation, the core body temperature started to increase in the warming group whereas it continued to drop in the non-warming group. This difference was statistically significant. The final core body temperature after tourniquet deflation was significantly higher in the warming group (mean +/- SD 36.1 +/- 0.2 degrees C) than in the non-warming group (35.4 +/- 0.3 degrees C). Intra-operative forced-air warming increased the core body temperature before tourniquet deflation and prevented subsequent hypothermia in elderly patients under general anaesthesia.

Resistive Polymer Versus Forced-Air Warming: Comparable Heat Transfer and Core Rewarming Rates in Volunteers

Mild perioperative hypothermia increases the risk of several severe complications. Perioperative patient warming to preserve normothermia has thus become routine, with forced-air warming being used most often. In previous studies, various resistive warming systems have shown mixed results in comparison with forced-air. Recently, a polymer-based resistive patient warming system has been developed. We compared the efficacy of a standard forced-air warming system with the resistive polymer system in volunteers. Eight healthy volunteers participated, each on two separate study days. Unanesthetized volunteers were cooled to a core temperature (tympanic membrane) of 34 degrees C by application of forced-air at 10 degrees C and a circulating-water mattress at 4 degrees C. Meperidine and buspirone were administered to prevent shivering. In a randomly designated order, volunteers were then rewarmed (until their core temperatures reached 36 degrees C) with one of the following active warming systems: (1) forced-air warming (Bair Hugger warming cover #300, blower #750, Arizant, Eden Prairie, MN); or (2) polymer fiber resistive warming (HotDog whole body blanket, HotDog standard controller, Augustine Biomedical, Eden Prairie, MN). The alternate system was used on the second study day. Metabolic heat production, cutaneous heat loss, and core temperature were measured. Metabolic heat production and cutaneous heat loss were similar with each system. After a 30-min delay, core temperature increased nearly linearly by 0.98 (95% confidence interval 0.91-1.04) degrees C/h with forced-air and by 0.92 (0.85-1.00) degrees C/h with resistive heating (P = 0.4). Heating efficacy and core rewarming rates were similar with full-body forced-air and full-body resistive polymer heating in healthy volunteers.

Comparison of Three Warming Devices for the Prevention of Core Hypothermia and Post-Anaesthesia Shivering

The efficacy of forced air warming with a surgical access blanket in preventing a decrease in core temperature during anaesthesia and post-anaesthesia shivering (PAS) was compared with two widely used interventions comprising forced air warming combined with an upper body blanket, and a circulating water mattress, in a prospective, randomized double-blind study. A total of 90 patients undergoing total abdominal hysterectomy were studied, 30 in each group. Core temperature was measured 15, 30, 45, 60, 90 and 120 min after induction of anaesthesia. PAS was evaluated every 5 min after emergence from anaesthesia over a period of 1 h. Core temperature fell in all three groups compared with the baseline, but forced air warming using a surgical access blanket was more effective than the other warming methods in ameliorating the temperature decrease. The surgical access blanket was also superior to the circulating water mattress in reducing PAS.

Aboriginal Art in California and Queen Charlotte's Island

IN the fourth volume, recently issued, of the Proceedings of the Davenport Academy of Natural Sciences there is a valuable article by Dr. W. J. Hoffman on “Aboriginal Art in California and Queen Charlotte's Island.” In the summer of 1884 Dr. Hoffman visited the Pacific coast for the purpose of continuing his researches on primitive art, and he was fortunate enough to find a number of localities in which there are painted and “etched” records, of considerable interest, made by Indians belonging to tribes now unknown. These records occur in groups. One group, the first described by Dr. Hoffman, is in the neighbourhood of Santa Barbara. The best preserved paintings in this series are in a cavity which measures about twenty feet wide and eight feet high. The rock consists of gray sandstone, but the ceiling and back portion of the cave have a yellowish appearance. The colours employed were red ochre, white, and bluish black. Some of the paintings Dr. Hoffman takes to be representations of gaudily-coloured blankets. In several instances a grotesque human figure is drawn over or in front of what seems to be a blanket, as if the latter were intended as a body blanket or serape. In the Azuza cañon, about thirty miles north-east of Los Angeles, Dr. Hoffman examined a second series of painted records. Rudely sketched human figures are represented a pointing in certain directions, and the intention evidently was that they should serve as guides to travelling parties. For instance, the left arm of a figure on a white granitic boulder points towards the north-east. The precipitous walls of the cañon make egress in that direction impossible, but two hundred yards further on the cañon makes a sharp turn towards the north-east, and in rounding the point of land to the right the traveller comes to another boulder, on which are numerous faint drawings of various kinds. This boulder is on the line of an old trail leading from the country of the Chemehuevi, on the north of the mountains, down to the valley settlements of San Gabriel and Los Angeles. A third series of records was found in the southern part of Owens Valley, California, between the White Mountains on the east and the Benton Range on the west. They are “etched,” not painted. The most common characters in this group are circles, either plain, nucleated, bisected, concentric, or spectacle-shaped, by pairs or threes, with various forms of interior ornamentation. This group resembles etchings in the Canary Islands so closely that the illustrations given by Dr. Hoffman serve for both localities. On one of his plates he presents a number of circles with ornamented interiors, from a simple bisection to the stellate and cruciform varieties. Similar circles bearing cross-lines occur at Grevinge, Zeeland; and other forms resembling some at Owens Valley are found at Slieve-na-Calliagh, Grange, and Dowth, in Ireland. The spectacle-shaped variety resembles the mysterious symbol on some Scottish monuments which has given rise to so much vague speculation. The reversed Z, however, is wanting in the Californian examples. Of the various outlines of the human form presented by Mr. Wallace from Brazil, and referred to more recently by Prof. Richard Andree in “Ethnographische Parallelen und Vergleiche,” a considerable number are almost identical with etchings in the Owens Valley series. Many of the characters in these three Californian groups are similar to, and some are indistinguishable from, those made by the Moki and other tribes of the Shoshonian linguistic stock. Further research on the same Jines may, therefore, enable anthropologists to determine the former geographical area of the Shoshonian family, as has already been done in the case of the Algonkian tribes.