The accuracy of a disposable noninvasive core thermometer

Ain-Shams Journal of Anesthesiology

Background Perioperative hypothermia is an unintended decrease in the core temperature of patients. Hypothermia has many proven complications. The aim of this study is to investigate the perioperative temperature monitoring rates and the difficulties encountered during monitoring, particularly in patients undergoing neuraxial anesthesia. Methods Two hundred anesthesiologists were included in the study who work in Turkey and actively work in an operating room. A questionnaire was applied to the participants via printed form or e-mail. Results In Turkey, the overall temperature monitoring ratio was measured as 5.5%. Temperature monitoring was the most frequently used for cardiovascular surgery patients group. In neuraxial anesthesia, temperature monitoring was only 1.5%. The most common reason for not using a temperature monitor was the lack of appropriate equipment (45%). The most common temperature monitoring area was the axillary zone (48%). Conclusion Participants were aware of th...

Anesthesiology, 2008

Most clinically available thermometers accurately report the temperature of whatever tissue is being measured. The difficulty is that no reliably core-temperature measuring sites are completely non-invasive and easy to use — especially in patients not having general anesthesia. Nonetheless, temperature can be reliably measured in most patients. Body temperature should be measured in patients having general anesthesia exceeding 30 minutes in duration, and in patients having major operations under neuraxial anesthesia.Core body temperature is normally tightly regulated. All general anesthetics produce a profound dose-dependent reduction in the core temperature triggering cold defenses including arterio-venous shunt vasoconstriction and shivering. Anesthetic-induced impairment of normal thermoregulatory control, and the resulting core-to-peripheral redistribution of body heat, is the primary cause of hypothermia in most patients. Neuraxial anesthesia also impairs thermoregulatory control, although to a lesser extant than general anesthesia. Prolonged epidural analgesia is associated with hyperthermia whose cause remains unknown.

Journal of Clinical Monitoring and Computing, 2022

Perioperative hypothermia is still common and has relevant complication for the patient. An effective perioperative thermal management requires essentially an accurate method to measure core temperature. So far, only one study has investigated the new Temple Touch Pro™ (Medisim Ltd., Beit-Shemesh, Israel). during anesthesia Therefore, we assessed the agreement between the Temple Touch Pro™ thermometer (TTP) and distal esophageal temperature (T Eso) in a second study. After approval by the local ethics committee we studied 100 adult patients undergoing surgery with general anesthesia. Before induction of anesthesia the TTP sensor unit was attached to the skin above the temporal artery. After induction of anesthesia an esophageal temperature probe was placed in the distal esophagus. Recordings started 10 min after placement of the esophageal temperature probe to allow adequate warming of the probes. Pairs of temperature values were documented in five-minute intervals until emergence of anesthesia. Accuracy of the two methods was assessed by Bland-Altman comparisons of differences with multiple measurements. Core temperatures obtained with the TTP in adults showed a mean bias of-0.04 °C with 95% limits of agreement within − 0.99 °C to + 0.91 °C compared to an esophageal temperature probe. We consider the TTP as a reasonable tool for perioperative temperature monitoring. It is not accurate enough to be used as a reference method in scientific studies, but may be a useful tool especially for conscious patients undergoing neuraxial anesthesia or regional anesthesia with sedation. Trial registration This study was registered in the German Clinical Trials Register (DRKS-ID: 00024050), day of registration 12/01/2021.

Journal of perianesthesia nursing : official journal of the American Society of PeriAnesthesia Nurses, 2018

To evaluate the agreement of temporal artery temperature (Tat) with esophageal temperature (Tes) and oral temperature (Tor), and explore potential factors associated with the level of agreement between the thermometry methods in different clinical settings. A prospective repeated measures (induction, emergence, and postanesthesia care unit) design was used. Temperature data were collected for 54 patients receiving general anesthesia. Analyses included descriptive statistics, paired t tests for the within-patient comparison of temperature methods, Bland-Altman plots to examine agreement between methods, and multiple linear regression to identify factors associated with the agreement between methods. Tat was significantly higher compared with Tes and Tor (P < .05) and was poor at detecting hypothermia. The use of a muscle relaxant and surgical site were suggested to be associated with the difference between Tat and Tes at emergence. Tat is more convenient, but less accurate, than o...

Anesthesiology, 2009

Background: Initial postoperative core temperature is a physician and hospital performance measure. However, the extent to which core temperature changes during emergence from anesthesia and transport from the operating room to the postanesthesia care unit (PACU) remains unknown. Similarly, the accuracy of many noninvasive temperature-monitoring methods used in the PACU has yet to be quantified. This study, therefore, quantified the change in core temperature occurring during emergence and transport and evaluated the accuracy and precision of eight noninvasive thermometers in the PACU.

Journal of Anaesthesiology Clinical Pharmacology, 2017

Thermoregulation is based on multiple signals coming from nearly every type of tissue. The processing of thermal information occurs in three phases: afferent input, central Administration of general anesthesia requires continuous monitoring of vital parameters of the body including body temperature. However, temperature continues to be one of the least seriously monitored parameters perioperatively. Inadvertent perioperative hypothermia is a relatively common occurrence with both general and regional anesthesia and can have significant adverse impact on patients' outcome. While guidelines for perioperative temperature management have been proposed, there are no specific guidelines regarding the best site or best modality of temperature monitoring and management intraoperatively. Various warming and cooling devices are available which help maintain perioperative normothermia. This article discusses the physiology of thermoregulation, effects of anesthesia on thermoregulation, various temperature monitoring sites and methods, perioperative warming devices, guidelines for perioperative temperature management and inadvertent temperature complications (hypothermia/hyperthermia) and measures to control it in the operating room.

Intraoperative management of patient body temperature is a standard of care for practicing anesthesiologists. Merely complying with the Surgical Care Improvement Project (SCIP) measurement is inadequate for optimizing perioperative outcomes. Clinicians should have a sound understanding of available temperature monitoring sites, deleterious effects of hypothermia, and indications for therapeutic hypothermia. This foundation will help physicians use indicated modalities to improve patient outcomes throughout the perioperative period. The purpose of this paper is to review appropriate intraoperative temperature monitoring, the importance of maintaining normothermia, and indications for intraoperative hypothermia.

British Journal of Anaesthesia, 2009

Background. Accurate measurement of core temperature is a standard component of perioperative and intensive care patient management. However, core temperature measurements are difficult to obtain in awake patients. A new non-invasive thermometer has been developed, combining two sensors separated by a known thermal resistance ('double-sensor' thermometer). We thus evaluated the accuracy of the double-sensor thermometer compared with a distal oesophageal thermometer to determine if the double-sensor thermometer is a suitable substitute. Methods. In perioperative and intensive care patient populations (n=68 total), double-sensor measurements were compared with measurements from a distal oesophageal thermometer using Bland-Altman analysis and Lin's concordance correlation coefficient (CCC). Results. Overall, 1287 measurement pairs were obtained at 5 min intervals. Ninety-eight per cent of all double-sensor values were within +0.58C of oesophageal temperature. The mean bias between the methods was 20.088C; the limits of agreement were 20.668C to 0.508C. Sensitivity and specificity for detection of fever were 0.86 and 0.97, respectively. Sensitivity and specificity for detection of hypothermia were 0.77 and 0.93, respectively. Lin's CCC was 0.93. Conclusions. The new double-sensor thermometer is sufficiently accurate to be considered an alternative to distal oesophageal core temperature measurement, and may be particularly useful in patients undergoing regional anaesthesia.

Journal of clinical …, 2005

Study Objective: The aim of this study was to test the hypothesis that the intraoperative pharyngeal temperatures obtained on the perilaryngeal airway (PLA), a novel airway device with a larger pharyngeal cuff (when inflated) than the laryngeal mask airway, are similar to tympanic membrane core temperatures. Design: This study is a prospective, simultaneous device comparison. Setting: This study was set at a university hospital. Patients: The study patients included 14 adults with American Society of Anesthesiologists physical statuses I and II, scheduled for minor gynecological or orthopedic surgery. Interventions: A PLA was inserted into the pharynx after induction of general anesthesia. Thermocouples were positioned at 3 sites on the PLA: (1) posterior portion of the head of the airway (tip), (2) midposterior portion of the cuff, and (3) left and right lateral-posterior portions of the cuff. Tympanic membrane thermocouples were inserted. Measurements: Temperature readings from the airway and the tympanic membrane thermocouples were recorded every 15 minutes throughout surgery.

Anaesthesiology Intensive Therapy, 2021

Core body temperature is strictly regulated (± 0.2 °C) and coordinated at the level of central nervous system located in the hypothalamus via several protective effector mechanisms that prevent overcooling and overheating. The central regulation permits both circadian and monthly variations of even 1°C; under normal conditions, however, the activation of effective protective mechanisms prevents even the slightest overcooling and core temperature elevation at any moment of the day. Anaesthesia (both general and block) limits the protective capacities of the body in this regard, increasing the range of temperatures accepted by the thermoregulation centre from several tenths to even several degrees Celsius, which is one of the factors favouring intraoperative hypothermia. The periphe ral vasodilation, caused either by the direct effects of general anaesthetics or sympathetic nerve blocks, is responsible for the initial rapid decrease in core temperature. The higher rate of heat loss, as compared to heat production further reduces the thermal reserves of the body during the next hours of surgery, which results in a decrease in core temperature even by 2-3°C. The above changes can lead to coagulation disorders, higher risk of perioperative transfusions, increased incidence of surgical site infections resulting in longer hospital stays and higher costs of hospitalisation [1]. Intraoperative hypothermia is defined as the drop in core temperature below 36 o C at any point of anaesthesia. The temperature measurements during both general anaesthesia and nerve blocks are an essential element of intraoperative monitoring to detect, treat and prevent this most common anaesthesiaassociated complication [2].