Normal body temperature and the effects of age, sex, ambient temperature and body mass index on normal oral temperature: a prospective, comparative study

Activated nitinol compression staples are associated with favorable biomechanical properties for talonavicular arthrodesis

Background

Nitinol compression staple use in foot and ankle arthrodesis procedures, including for the talonavicular joint, has gained acceptance. A previous study provided evidence for using nitinol compression staples in talonavicular arthrodesis (TNA) based on functional biomechanical testing comparisons to "gold standard" lag screw fixation. This study aimed to further compare the functional biomechanical properties of nitinol compression staple fixation to lag screw fixation for arthrodesis of the talonavicular joint. Body-temperature incubation and ankle inversion and eversion loading sequences were added to previously reported biomechanical testing.

Methods

Robotic testing was performed on cadaveric feet (n = 10; 5 matched pairs) after TNA using either two nitinol compression staples or two fully threaded lag screws. TNA method was randomized, alternating between matched-pairs of left and right feet. After surgical stabilization, specimens were incubated at 38 °C for 24 h to simulate the initial postoperative period in a patient. After plantarflexion and dorsiflexion testing, the specimens underwent inversion and eversion testing, cycling from 20° inversion to 10° eversion for 10 cycles. Displacements were tracked using optical tracking markers. Significant (p < 0.05) differences between staple versus screw fixation cohorts were determined using paired t-Tests.

Results

All specimens completed testing with none experiencing failure at the TNF. No statistically significant differences in functional biomechanical testing properties were noted between nitinol compression staple fixation and lag screw fixation for TNA.

Conclusion

The study findings provide additional support for nitinol compression staple fixation as an option for talonavicular arthrodesis fixation. Taken together, the results of functional biomechanical testing studies have provided sufficient evidence for initiation of a prospective clinical outcomes study using nitinol compression staples for talonavicular arthrodesis fixation at our institution.

Formulation optimization and evaluation of oromucosal in situ gel loaded with silver nanoparticles prepared by green biosynthesis

Treating oral diseases remains challenging as API is quickly washed out of the application site by saliva turnover and mouth movements. In situ gels are a class of application forms that present sol-gel transition's ability as a response to stimuli. Their tunable properties are provided using smart polymers responsible for stimuli sensitivity, often providing mucoadhesivity. In this study, antimicrobial in situ gels of thermosensitive and pH-sensitive polymers loaded with silver nanoparticles were prepared and evaluated. The nanoparticles were prepared by green synthesis using Agrimonia eupatoria L. extract. According to the data analysis, the in situ gel with the most promising profile contained 15 % of Pluronic® F-127, 0.25 % of methylcellulose, and 0.1 % of Noveon® AA-1. Pluronic® F-127 and methylcellulose significantly increased the viscosity of in situ gels at 37 °C and shear rates similar to speaking and swallowing. At 20 °C, a behavior close to a Newtonian fluid was observed while being easily injectable (injection force 13.455 ± 1.973 N). The viscosity of the formulation increased with temperature and reached 2962.77 ± 63.37 mPa·s (37 °C). A temperature increase led to increased adhesiveness and rigidity of the formulation. The critical sol-gel transition temperature at physiological pH was 32.65 ± 0.35 °C. 96.77 ± 3.26 % of Ag NPs were released by erosion and dissolution of the gel after 40 min. The determination of MIC showed effect against E. coli and S. aureus (0.0625 mM and 0.5000 mM, respectively). The relative inhibition zone diameter of the in situ gel was 73.32 ± 11.06 % compared to gentamicin sulfate. This work discusses the optimization of the formulation of novel antibacterial in situ gel for oromucosal delivery, analyses the impact of the concentration of excipients on the dependent variables, and suggests appropriate evaluation of the formulation in terms of its indication. This study offers a promising dosage form for local treatment of oral diseases.

Defining Usual Oral Temperature Ranges in Outpatients Using an Unsupervised Learning Algorithm

Importance

Although oral temperature is commonly assessed in medical examinations, the range of usual or "normal" temperature is poorly defined.

Objective

To determine normal oral temperature ranges by age, sex, height, weight, and time of day.

Design, Setting, and Participants

This cross-sectional study used clinical visit information from the divisions of Internal Medicine and Family Medicine in a single large medical care system. All adult outpatient encounters that included temperature measurements from April 28, 2008, through June 4, 2017, were eligible for inclusion. The LIMIT (Laboratory Information Mining for Individualized Thresholds) filtering algorithm was applied to iteratively remove encounters with primary diagnoses overrepresented in the tails of the temperature distribution, leaving only those diagnoses unrelated to temperature. Mixed-effects modeling was applied to the remaining temperature measurements to identify independent factors associated with normal oral temperature and to generate individualized normal temperature ranges. Data were analyzed from July 5, 2017, to June 23, 2023.

Exposures

Primary diagnoses and medications, age, sex, height, weight, time of day, and month, abstracted from each outpatient encounter.

Main Outcomes and Measures

Normal temperature ranges by age, sex, height, weight, and time of day.

Results

Of 618 306 patient encounters, 35.92% were removed by LIMIT because they included diagnoses or medications that fell disproportionately in the tails of the temperature distribution. The encounters removed due to overrepresentation in the upper tail were primarily linked to infectious diseases (76.81% of all removed encounters); type 2 diabetes was the only diagnosis removed for overrepresentation in the lower tail (15.71% of all removed encounters). The 396 195 encounters included in the analysis set consisted of 126 705 patients (57.35% women; mean [SD] age, 52.7 [15.9] years). Prior to running LIMIT, the mean (SD) overall oral temperature was 36.71 °C (0.43 °C); following LIMIT, the mean (SD) temperature was 36.64 °C (0.35 °C). Using mixed-effects modeling, age, sex, height, weight, and time of day accounted for 6.86% (overall) and up to 25.52% (per patient) of the observed variability in temperature. Mean normal oral temperature did not reach 37 °C for any subgroup; the upper 99th percentile ranged from 36.81 °C (a tall man with underweight aged 80 years at 8:00 am) to 37.88 °C (a short woman with obesity aged 20 years at 2:00 pm).

Conclusions and Relevance

The findings of this cross-sectional study suggest that normal oral temperature varies in an expected manner based on sex, age, height, weight, and time of day, allowing individualized normal temperature ranges to be established. The clinical significance of a value outside of the usual range is an area for future study.

A Continuously Worn Dual Temperature Sensor System for Accurate Monitoring of Core Body Temperature from the Ear Canal

The objective of this work was to develop a temperature sensor system that accurately measures core body temperature from an ear-worn device. Two digital temperature sensors were embedded in a hearing aid shell along the thermal gradient of the ear canal to form a linear heat balance relationship. This relationship was used to determine best fit parameters for estimating body temperature. The predicted body temperatures resulted in intersubject limits of agreement (LOA) of ±0.49 °C over a range of physiologic and ambient temperatures without calibration. The newly developed hearing aid-based temperature sensor system can estimate core body temperature at an accuracy level equal to or better than many devices currently on the market. An accurate, continuously worn, temperature monitoring and tracking device may help provide early detection of illnesses, which could prove especially beneficial during pandemics and in the elderly demographic of hearing aid wearers.

An Ambiguous Role for Fever in Worsening Outcome After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and leaves most survivors with impairments. Fever, a rise in the thermoregulatory set point, complicates ICH. This review summarizes ICH fever studies and employs meta-analytic techniques to explore the relationship between fever and ICH. We discuss methodological considerations for future studies and provide an overview of mechanisms by which fever, and its treatment, may impact ICH. We searched the PubMed database using the following terms: ((fever OR hyperthermia) AND (intracerebral hemorrhage OR intraparenchymal hemorrhage OR intracerebral haemorrhage OR intraparenchymal haemorrhage)). Our search returned 727 studies, of which 21 were included in our final analysis, consisting of 19 clinical, and two preclinical, studies. We conducted a meta-analysis on the clinical data to quantify how fever is related to mortality, functional outcomes, and intraventricular hemorrhage. Analysis of clinical studies suggested that fever causes an increased risk of mortality but does not appear to be associated with poor outcomes among survivors, making it difficult to ascertain the extent of harm caused by post-ICH fever or the benefits of its treatment. Perhaps these inconsistencies stem from variable fever definitions, and temperature measurement and fever treatment protocols. Additionally, the lack of mechanistic data in clinical studies coupled with preclinical studies showing no harmful effects of moderate bouts of hyperthermia raise concerns about the direct contribution of hyperthermia and fever in post ICH outcome. Overall, the significance of temperature increases after ICH is unclear, making this an important area for future research.

A Comparative Study of Forehead Temperature and Core Body Temperature under Varying Ambient Temperature Conditions

When the ambient temperature, in which a person is situated, fluctuates, the body's surface temperature will alter proportionally. However, the body's core temperature will remain relatively steady. Consequently, using body surface temperature to characterize the core body temperature of the human body in varied situations is still highly inaccurate. This research aims to investigate and establish the link between human body surface temperature and core body temperature in a variety of ambient conditions, as well as the associated conversion curves.

METHODS

Plan an experiment to measure temperature over a thousand times in order to get the corresponding data for human forehead, axillary, and oral temperatures at varying ambient temperatures (14-32 °C). Utilize the axillary and oral temperatures as the core body temperature standards or the control group to investigate the new approach's accuracy, sensitivity, and specificity for detecting fever/non-fever conditions and the forehead temperature as the experimental group. Analyze the statistical connection, data correlation, and agreement between the forehead temperature and the core body temperature.

RESULTS

A total of 1080 tests measuring body temperature were conducted on healthy adults. The average axillary temperature was (36.7 ± 0.41) °C, the average oral temperature was (36.7 ± 0.33) °C, and the average forehead temperature was (36.2 ± 0.30) °C as a result of the shift in ambient temperature. The forehead temperature was 0.5 °C lower than the average of the axillary and oral temperatures. The Pearson correlation coefficient between axillary and oral temperatures was 0.41 (95% CI, 0.28-0.52), between axillary and forehead temperatures was 0.07 (95% CI, -0.07-0.22), and between oral and forehead temperatures was 0.26 (95% CI, 0.11-0.39). The mean differences between the axillary temperature and the oral temperature, the oral temperature and the forehead temperature, and the axillary temperature and the forehead temperature were -0.08 °C, 0.49 °C, and 0.42 °C, respectively, according to a Bland-Altman analysis. Finally, the regression analysis revealed that there was a linear association between the axillary temperature and the forehead temperature, as well as the oral temperature and the forehead temperature due to the change in ambient temperature.

CONCLUSION

The changes in ambient temperature have a substantial impact on the temperature of the forehead. There are significant differences between the forehead and axillary temperatures, as well as the forehead and oral temperatures, when the ambient temperature is low. As the ambient temperature rises, the forehead temperature tends to progressively converge with the axillary and oral temperatures. In clinical or daily applications, it is not advised to utilize the forehead temperature derived from an uncorrected infrared thermometer as the foundation for a body temperature screening in public venues such as hospital outpatient clinics, shopping malls, airports, and train stations.

Characterization of Surgical Tools for Specific Endovascular Navigation

PURPOSE

The aim of this work was to mechanically characterize a specific active guidewire and catheters that are commercially available, for further implementation into numerical simulation of endovascular navigation towards complex targets.

METHODS

For the guidewire, 3-point bending tests and bending with added masses were used to obtain the Young moduli of its various components. To study its behavior, the guidewire was activated under "ideal" conditions and its performance was investigated. As for the various catheters, they were measured and 3-point bending tests were conducted to determine their mechanical properties.

RESULTS & CONCLUSION

The Young moduli of the shaft and the distal tip of the guidewire were determined. We defined a suitable current intensity to activate the guidewire related to an optimal curvature. Then, the time of activation/deactivation was measured at 1.7 s. On the flip side, parts of the catheters were considered either elastic or viscoelastic. In all cases, the rigidity gradients along the various catheters were highlighted. The characterization of the aforementioned surgical tools provides the opportunity to simulate the endovascular nagivation process.

Infrared Thermography for Measuring Elevated Body Temperature: Clinical Accuracy, Calibration, and Evaluation

Infrared thermographs (IRTs) implemented according to standardized best practices have shown strong potential for detecting elevated body temperatures (EBT), which may be useful in clinical settings and during infectious disease epidemics. However, optimal IRT calibration methods have not been established and the clinical performance of these devices relative to the more common non-contact infrared thermometers (NCITs) remains unclear. In addition to confirming the findings of our preliminary analysis of clinical study results, the primary intent of this study was to compare methods for IRT calibration and identify best practices for assessing the performance of IRTs intended to detect EBT. A key secondary aim was to compare IRT clinical accuracy to that of NCITs. We performed a clinical thermographic imaging study of more than 1000 subjects, acquiring temperature data from several facial locations that, along with reference oral temperatures, were used to calibrate two IRT systems based on seven different regression methods. Oral temperatures imputed from facial data were used to evaluate IRT clinical accuracy based on metrics such as clinical bias (Δcb), repeatability, root-mean-square difference, and sensitivity/specificity. We proposed several calibration approaches designed to account for the non-uniform data density across the temperature range and a constant offset approach tended to show better ability to detect EBT. As in our prior study, inner canthi or full-face maximum temperatures provided the highest clinical accuracy. With an optimal calibration approach, these methods achieved a Δcb between ±0.03 °C with standard deviation (σΔcb) less than 0.3 °C, and sensitivity/specificity between 84% and 94%. Results of forehead-center measurements with NCITs or IRTs indicated reduced performance. An analysis of the complete clinical data set confirms the essential findings of our preliminary evaluation, with minor differences. Our findings provide novel insights into methods and metrics for the clinical accuracy assessment of IRTs. Furthermore, our results indicate that calibration approaches providing the highest clinical accuracy in the 37-38.5 °C range may be most effective for measuring EBT. While device performance depends on many factors, IRTs can provide superior performance to NCITs.

Smart Face Mask with an Integrated Heat Flux Sensor for Fast and Remote People's Healthcare Monitoring

The COVID-19 pandemic has highlighted a large amount of challenges to address. To combat the spread of the virus, several safety measures, such as wearing face masks, have been taken. Temperature controls at the entrance of public places to prevent the entry of virus carriers have been shown to be inefficient and inaccurate. This paper presents a smart mask that allows to monitor body temperature and breathing rate. Body temperature is measured by a non-invasive dual-heat-flux system, consisting of four sensors separated from each other with an insulating material. Breathing rate is obtained from the temperature changes within the mask, measured with a thermistor located near the nose. The system communicates by means of long-range (LoRa) backscattering, leading to a reduction in average power consumption. It is designed to establish the relative location of the smart mask from the signal received at two LoRa receivers installed inside and outside an access door. Low-cost LoRa transceivers with WiFi capabilities are used in the prototype to collect information and upload it to a server. Accuracy in body temperature measurements is consistent with measurements made with a thermistor located in the armpit. The system allows checking the correct placement of the mask based on the recorded temperatures and the breathing rate measurements. Besides, episodes of cough can be detected by sudden changes in thermistor temperature.

Understanding protein digestion in infants and the elderly: Current in vitro digestion models

The last decades have witnessed a surge of interest in the fate of dietary proteins during gastrointestinal (GI) digestion. Although several in vitro digestion models are available as alternatives to clinical experiments, most of them focus on the digestive conditions of healthy young adults. This study investigates the static/dynamic models used to simulate digestion in infants and the elderly and considers the related in vivo conditions. The in vitro digestive protocols targeting these two groups are summarized, and the challenges associated with the further development of in vitro digestion models are discussed. Static models rely on several factors (e.g., enzyme concentration, pH, reaction time, and rotation speed) to differentiate digestive conditions depending on age. Dynamic models can more accurately simulate the complex digestion process and allow the inclusion of further parameters (sequential secretion of digestive fluids, gradual changes in pH, peristaltic mixing, GI emptying, and the inoculation of luminal microbiota). In the case of infants, age or growth stage clarification and the differentiation of digestive protocols between full-term and preterm infants are required, whereas protocols dealing with various health statuses are required in the case of the elderly, as this group is prone to oral cavity and GI function deterioration.

Evaluation of a wearable wireless device with artificial intelligence, iThermonitor WT705, for continuous temperature monitoring for patients in surgical wards: a prospective comparative study

OBJECTIVES

To evaluate a new-generation, non-invasive, wireless axillary thermometer with artificial intelligence, iThermonitor (WT705, Raiing Medical, Beijing, China), and to ascertain its feasibility for perioperative continuous body temperature monitoring in surgical patients.

SETTING

Departments of Biliary Surgery and Operating Room and the post-anaesthesia care unit of a university teaching hospital in Chengdu, China.

PARTICIPANTS

A total of 526 adult surgical patients were consecutively enrolled.

DESIGN

This was a prospective observational study. Axillary temperatures were continuously recorded with iThermonitor throughout the whole perioperative period. The temperatures of the contralateral armpit were measured with mercury thermometers at 8:00, 12:00, 16:00 and 20:00 every day and were used as references.

OUTCOME MEASURES

The outcomes were the accuracy and precision of the temperatures measured with iThermonitor, the validity to detect fever and the feasibility of continuous wear. Pairs of temperatures were evaluated with Student's t-test, Pearson's correlation and repeated-measures Bland-Altman plot.

RESULTS

A total of 3621 pairs of body temperatures were obtained. The temperatures measured with iThermonitor agreed with those measured with the mercury thermometers overall, with a mean difference of 0.03°C±0.35°C and a moderate correlation (r=0.755, p<0.001). The 95% limits of agreement (LoA) ranged from -0.63°C to 0.73°C, with 5.11% of the differences outside the 95% LoA. The intraclass correlation coefficient was 0.753. Continuous temperature monitoring captured more fevers than intermittent observation (117/526 vs 91/526, p<0.001), detected fever up to 4.35 hours earlier, and captured a higher peak temperature (0.29°C±0.27°C, 95% CI: 0.26-0.31). All subjects felt that wearing iThermonitor was more or less comfortable and did not affect their daily activities.

CONCLUSIONS

iThermonitor is promising for continuous remote temperature monitoring in surgical patients. However, further developments are still needed to improve the precision of this device, especially for temperature detection in underweight patients and those with lower body temperature.

TRIAL REGISTRATION NUMBER

ChiCTR1900024549; Results (registered on 5 July 2019).

Fever Incidence Is Much Lower in the Morning than the Evening: Boston and US National Triage Data

INTRODUCTION

In this observational study, we evaluated time-of-day variation in the incidence of fever that is seen at triage. The observed incidence of fever could change greatly over the day because body temperatures generally rise and fall in a daily cycle, yet fever is identified using a temperature threshold that is unchanging, such as ≥38.0° Celsius (C) (≥100.4° Fahrenheit [F]).

METHODS

We analyzed 93,225 triage temperature measurements from a Boston emergency department (ED) (2009-2012) and 264,617 triage temperature measurements from the National Hospital Ambulatory Medical Care Survey (NHAMCS, 2002-2010), making this the largest study of body temperature since the mid-1800s. Boston data were investigated exploratorily, while NHAMCS was used to corroborate Boston findings and check whether they generalized. NHAMCS results are nationally representative of United States EDs. Analyses focused on adults.

RESULTS

In the Boston ED, the proportion of patients with triage temperatures in the fever range (≥38.0°C, ≥100.4°F) increased 2.5-fold from morning to evening (7:00-8:59 PM vs 7:00-8:59 AM: risk ratio [RR] 2.5, 95% confidence interval [CI], 2.0-3.3). Similar time-of-day changes were observed when investigating alternative definitions of fever: temperatures ≥39.0°C (≥102.2°F) and ≥40.0°C (≥104.0°F) increased 2.4- and 3.6-fold from morning to evening (7:00-8:59 PM vs 7:00-8:59 AM: RRs [95% CIs] 2.4 [1.5-4.3] and 3.6 [1.5-17.7], respectively). Analyses of adult NHAMCS patients provided confirmation, showing mostly similar increases for the same fever definitions and times of day (RRs [95% CIs] 1.8 [1.6-2.1], 1.9 [1.4-2.5], and 2.8 [0.8-9.3], respectively), including after adjusting for 12 potential confounders using multivariable regression (adjusted RRs [95% CIs] 1.8 [1.5-2.1], 1.8 [1.3-2.4], and 2.7 [0.8-9.2], respectively), in age-group analyses (18-64 vs 65+ years), and in several sensitivity analyses. The patterns observed for fever mirror the circadian rhythm of body temperature, which reaches its highest and lowest points at similar times.

CONCLUSION

Fever incidence is lower at morning triages than at evening triages. High fevers are especially rare at morning triage and may warrant special consideration for this reason. Studies should examine whether fever-causing diseases are missed or underappreciated during mornings, especially for sepsis cases and during screenings for infectious disease outbreaks. The daily cycling of fever incidence may result from the circadian rhythm.

Magnetic resonance (MR) safety and compatibility of a novel iron bioresorbable scaffold

Fully bioresorbable scaffolds have been designed to overcome the limitations of traditional drug-eluting stents (DESs), which permanently cage the native vessel wall and pose possible complications. The ultrathin-strut designed sirolimus-eluting iron bioresorbable coronary scaffold system (IBS) shows comparable mechanical properties to traditional DESs and exhibits an adaptive degradation profile during target vessel healing, which makes it a promising candidate in all-comers patient population. For implanted medical devices, magnetic resonance (MR) imaging properties, including MR safety and compatibility, should be evaluated before its clinical use, especially for devices with intrinsic ferromagnetism. In this study, MR safety and compatibility of the IBS scaffold were evaluated based on a series of well-designed in-vitro, ex-vivo and in-vivo experiments, considering possible risks, including scaffold movement, over-heating, image artifact, and possible vessel injury, under typical MR condition. Traditional ASTM standards for MR safety and compatibility evaluation of intravascular devices were referred, but not only limited to that. The unique time-relevant MR properties of bioresorbable scaffolds were also discussed. Possible forces imposed on the scaffold during MR scanning and MR image artifacts gradually decreased along with scaffold degradation/absorption. Rigorous experiments designed based on a scientifically based rationale revealed that the IBS scaffold is MR conditional, though not MR compatible before complete absorption. The methodology used in the present study can give insight into the MR evaluation of magnetic scaffolds (bioresorbable) or stents (permanent).

Normal Body Temperature: A Systematic Review

PubMed was searched from 1935 to December 2017 with a variety of search phrases among article titles. The references of the identified manuscripts were then manually searched. The inclusion criteria were as follows: (1) the paper presented data on measured normal body temperature of healthy human subjects ages 18 and older, (2) a prospective design was used, and (3) the paper was written in or translated into the English language. Thirty-six articles met the inclusion criteria. This comprised 9227 measurement sites from 7636 subjects. The calculated ranges (mean ± 2 standard deviations) were 36.32-37.76 (rectal), 35.76-37.52 (tympanic), 35.61-37.61 (urine), 35.73-37.41 (oral), and 35.01-36.93 (axillary). Older adults (age ≥60) had lower temperature than younger adults (age <60) by 0.23°C, on average. There was only insignificant gender difference. Compared with the currently established reference point for normothermia of 36.8°C, our means are slightly lower but the difference likely has no physiological importance. We conclude that the most important patient factors remain site of measurement and patient's age.

Evaluation of commercial, wireless dermal thermometers for surrogate measurements of core temperature

Extensive research has been devoted to developing methods for assessing core body temperature, and to determine which method is most accurate. A number of wireless dermal thermometers for home use are presently available, but their relation to core body temperature and suitability for use in clinical research has hitherto not been assessed. The current study aimed to evaluate such thermometers by comparing them to the results of a rectal thermometer. Four wireless dermal thermometers for home use (FeverSmart, iThermonitor, Quest Temp Sitter, and Thermochron iButton) were applied to 15 patients during 24 h, and rectal temperature was measured at four occasions. Pearson correlation revealed moderate correlation for the Feversmart (r = 0.75), iThermonitor (r = 0.79), and Thermochron iButton (r = 0.71) systems. The Quest Temp Sitter system malfunctioned repeatedly, and the correlation (r = 0.29) for this method should therefore be assessed with caution. All dermal thermometers rendered lower average temperatures than Terumo c405 (Feversmart -0.70 ± 0.65 °C; iThermonitor -0.77 ± 0.53 °C, Quest Temp Sitter -1.18 ± 0.66 °C, and Thermochron iButton -0.87 ± 0.65 °C). Sensitivity of the dermal thermometers for detecting core temperatures ≥38.0 °C was low, ranging from 0.33 to 0.6, but improved to 0.60 to 0.80 after adjusting temperatures by the methods' average deviation from rectal temperature. The results from the dermal thermometers tested here showed an insufficient correlation to core temperature to be used for core temperature monitoring in clinical research and practice. Unfortunately, other options for non-invasive temperature measurements are few. The two thermometers with the least unsatisfactory performance profile in our evaluations were the Feversmart and iThermonitor systems.

Following in the footsteps of Hippocrates-interrelation between the incidence of odontogenic abscess and meteorological parameters

OBJECTIVES

Although many physicians in daily practice assume a connection between odontogenic infections and meteorological parameters, this has not yet been scientifically proven. Therefore, the aim of the present study was to evaluate the incidence of odontogenic abscess (OA) in relation to outdoor temperature and atmospheric pressure.

PATIENTS AND METHODS

An analysis of patients with an odontogenic abscess who presented at the emergency department within a period of 24 months was performed. Only patients who had not received surgical or antibiotic treatment prior to presentation and who lived in Berlin/Brandenburg were included. The OA incidence was correlated with the mean/maximum outdoor temperature and atmospheric pressure starting from 14 days before presentation. The statistical analysis was carried out using Poisson regression models with OA incidence as dependent and meteorological parameters as independent variables.

RESULTS

A total of 535 patients (mean age 39.4 years; range 1 to 95 years) with 538 cases were included. Of these, 227 were hospitalized. The most frequent diagnosis was a canine fossa abscess. A significant association between mean (p = 0.0153) and maximum temperature (p = 0.008) on the day of the presentation and abscess incidence was observed. Furthermore, a significant correlation between OA incidence and maximum temperature 2 days before presentation was found (p = 0.034). The deviation of the mean temperature on the day of the presentation from the monthly mean temperature had a significant influence (p = 0.021) on the incidence of OA. In contrast to temperature, atmospheric pressure had no significant influence on the incidence of OA.

CONCLUSION

This study supports a relationship between the incidence of odontogenic abscess and outdoor temperature, but not atmospheric pressure. A significantly higher frequency of patients with an OA presented at our emergency department on days with (comparably) low and high outdoor temperatures. Furthermore, a significant correlation between incidence and maximum temperature 2 days before presentation was found.

CLINICAL RELEVANCE

The treatment of odontogenic infections has become a significant economic burden to public health care facilities. The results of this study may help to adapt the numbers of doctors/dentists on duty in relation to different weather conditions. In any case, it is an impetus to think outside the box.

Odontogenic Abscess-Related Emergency Hospital Admissions: A Retrospective Data Analysis of 120 Children and Young People Requiring Surgical Drainage

Introduction

Even today, despite medical progress and intensive health education, odontogenic infections leading to surgical intervention and hospitalization are common in children and young people. The aim of this study was to give a detailed overview of clinical and economic data on children and young people treated and hospitalized due to an odontogenic abscess at a tertiary university hospital.

Methods

A single-center retrospective analysis of patients under the age of 18 years who were hospitalized and surgically treated under local or general anesthesia for an odontogenic abscess during a period of 24 months was performed.

Results

A total of 120 patients (77 males; 43 females) within the observation period of 2 years were included. The mean age was 6.3 years (ranging from 1 to 17 years). The most frequent diagnosis was a canine fossa abscess (n = 52; 43.3%) and the left primary maxillary first molar could be identified as the most frequent source of infection. The average length of hospital stay was 1.82 days (ranging from 0 to 8 days). The duration was significantly correlated with the kind of abscess diagnosed (p < 0.001) and the duration of the surgical intervention in patients who were treated under general anesthesia (rho = 0.259, p = 0.005). A statistically significant relationship was observed between the kind of abscess and cost (p < 0.001).

Conclusion

The length of hospital stay was significantly correlated with the kind of abscess diagnosed. The left primary maxillary first molar could be identified as the most frequent source of infection. A statistically significant relationship was observed between the kind of abscess and cost.

Thermoregulation and age

The thermoregulatory functions may vary with age. Thermosensitivity is active in neonates and children; both heat production and heat loss effector mechanisms are functional but easily exhaustable. Proportional and lasting defense against thermal challenges is difficult, and both hypothermia and hyperthermia may easily develop. Febrile or hypothermic responses to infections or endotoxin can also develop, together with confusion. In small children febrile convulsions may be dangerous. In old age the resting body temperature may be lower than in young adults. Further, thermosensitivity decreases, the thresholds for activating skin vasomotor and evaporative responses or metabolism are shifted, and responses to thermal challenges are delayed or insufficient: both hypothermia and hyperthermia may develop easily. Infection-induced fevers are often limited or absent, or replaced by hypothermia. Various types of brain damage may induce special forms of hypothermia, hyperthermia, or severe fever. Impaired mental state often accompanies hypothermia and hyperthermia, and may occasionally be a dominant feature of infection (instead of the most commonly observed fever). Aging brings about a turning point in women's life: the menopause. The well-known influence of regular hormonal cycles on the thermoregulation of a woman of fertile age gives way to menopausal hot flushes caused by estrogen withdrawal. Not all details of this thermoregulatory anomaly are fully understood yet.

Can body temperature dysregulation explain the co-occurrence between overweight/obesity, sleep impairment, late-night eating, and a sedentary lifestyle?

PURPOSE

Overweight/obesity, sleep disturbance, night eating, and a sedentary lifestyle are common co-occurring problems. There is a tendency for them to co-occur together more often than they occur alone. In some cases, there is clarity as to the time course and evolution of the phenomena. However, specific mechanism(s) that are proposed to explain a single co-occurrence cannot fully explain the more generalized tendency to develop concurrent symptoms and/or disorders after developing one of the phenomena. Nor is there a clinical theory with any utility in explaining the development of co-occurring symptoms, disorders and behaviour and the mechanism(s) by which they occur. Thus, we propose a specific mechanism-dysregulation of core body temperature (CBT) that interferes with sleep onset-to explain the development of the concurrences.

METHODS

A detailed review of the literature related to CBT and the phenomena that can alter CBT or are altered by CBT is provided.

RESULTS

Overweight/obesity, sleep disturbance and certain behaviour (e.g. late-night eating, sedentarism) were linked to elevated CBT, especially an elevated nocturnal CBT. A number of existing therapies including drugs (e.g. antidepressants), behavioural therapies (e.g. sleep restriction therapy) and bright light therapy can also reduce CBT.

CONCLUSIONS

An elevation in nocturnal CBT that interferes with sleep onset can parsimoniously explain the development and perpetuation of common co-occurring symptoms, disorders and behaviour including overweight/obesity, sleep disturbance, late-night eating, and sedentarism. Nonetheless, a significant correlation between CBT and the above symptoms, disorders and behaviour does not necessarily imply causation. Thus, statistical and methodological issues of relevance to this enquiry are discussed including the likely presence of autocorrelation.

LEVEL OF EVIDENCE

Level V, narrative review.

Effects of tissue susceptibility on brain temperature mapping

A method for mapping of temperature over a large volume of the brain using volumetric proton MR spectroscopic imaging has been implemented and applied to 150 normal subjects. Magnetic susceptibility-induced frequency shifts in gray- and white-matter regions were measured and included as a correction in the temperature mapping calculation. Additional sources of magnetic susceptibility variations of the individual metabolite resonance frequencies were also observed that reflect the cellular-level organization of the brain metabolites, with the most notable differences being attributed to changes of the N-Acetylaspartate resonance frequency that reflect the intra-axonal distribution and orientation of the white-matter tracts with respect to the applied magnetic field. These metabolite-specific susceptibility effects are also shown to change with age. Results indicate no change of apparent brain temperature with age from 18 to 84 years old, with a trend for increased brain temperature throughout the cerebrum in females relative for males on the order of 0.1°C; slightly increased temperatures in the left hemisphere relative to the right; and a lower temperature of 0.3°C in the cerebellum relative to that of cerebral white-matter. This study presents a novel acquisition method for noninvasive measurement of brain temperature that is of potential value for diagnostic purposes and treatment monitoring, while also demonstrating limitations of the measurement due to the confounding effects of tissue susceptibility variations.

Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals

The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.0, and at 35 and 28 °C, under static and shaking conditions for 72 h. Growth kinetics of biofilms were evaluated at 6, 24, 48 and 72 h. Biofilm milieu analysis were assessed by counting viable cells and quantification of nucleic acids released into biofilm supernatants. Biofilms were also analysed for proteolytic activity and antifungal resistance against amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole. Finally, ultrastructural characterization of biofilms formed in microtitre plates and catheter disks was performed by scanning electron microscopy. Greater biofilm formation was observed with a starter inoculum of 106 cells ml- 1, at pH 7.0 at 35 °C and 80 r.p.m., in both RPMI and Sabouraud media. Growth kinetics showed an increase in both viable cells and biomass with increasing incubation time, with maximum production at 48 h. Biofilms were able to disperse viable cells and nucleic acids into the supernatant throughout the developmental cycle. T. inkin biofilms produced more protease than planktonic cells and showed high tolerance to amphotericin B, caspofungin and azole derivatives. Mature biofilms were formed by different morphotypes, such as blastoconidia, arthroconidia and hyphae, in a strain-specific manner. The present article details the multicellular lifestyle of T. inkin and provides perspectives for further research.

Body temperature and thermal environment in a generalized arboreal anthropoid, wild mantled howling monkeys (Alouatta palliata)

Free-ranging primates are confronted with the challenge of maintaining an optimal range of body temperatures within a thermally dynamic environment that changes daily, seasonally, and annually. While many laboratory studies have been conducted on primate thermoregulation, we know comparatively little about the thermal pressures primates face in their natural, evolutionarily relevant environment. Such knowledge is critical to understanding the evolution of thermal adaptations in primates and for comparative evaluation of humans' unique thermal adaptations. We examined temperature and thermal environment in free-ranging, mantled howling monkeys (Alouatta palliata) in a tropical dry forest in Guanacaste, Costa Rica. We recorded subcutaneous (Tsc ) and near-animal ambient temperatures (Ta ) from 11 animals over 1586.5 sample hours during wet and dry seasons. Howlers displayed considerable variation in Tsc , which was largely attributable to circadian effects. Despite significant seasonal changes in the ambient thermal environment, howlers showed relatively little evidence for seasonal changes in Tsc . Howlers experienced warm thermal conditions which led to body cooling relative to the environment, and plateaus in Tsc at increasingly warm Ta . They also frequently faced cool thermal conditions (Ta  < Tsc ) in which Tsc was markedly elevated compared with Ta . These data add to a growing body of evidence that non-human primates have more labile body temperatures than humans. Our data additionally support a hypothesis that, despite inhabiting a dry tropical environment, howling monkeys experience both warm and cool thermal pressures. This suggests that thermal challenges may be more prevalent for primates than previously thought, even for species living in nonextreme thermal environments.

Comparison of three different thermometers in evaluating the body temperature of healthy young adult individuals

The aim of this study was to compare the measurement values obtained with a non-contact infrared thermometer, a tympanic thermometer and a chemical dot thermometer. The research population was composed of students studying in two departments of a university in Ankara. A total of 452 students who fit the inclusion criteria of the study and volunteered to participate were included in the sample. Body temperature measurements with different thermometers were performed by the same researcher at the same room temperature. Data were analyzed in a computerized environment by SPSS 15.0 statistical program pack and Bland-Altman graph. Mean age of healthy young adults participating in the study was 19.66 ± 0.94, and 55.1% of them were female. The agreement limits for non-contact infrared and chemical dot was between -1.30 and 0.32°C; for non-contact infrared and tympanic was between -1.26 and 0.13°C; and for chemical dot and tympanic -0.89 and 0.74°C. It was determined that, although the measurement values of the tympanic membrane and chemical dot thermometers conformed with each other, the conformity of the non-contact infrared thermometer was weak.

Relation between trends in body temperature and outcome in incident hemodialysis patients

BACKGROUND

Various biochemical and physiological variables are related to outcome in hemodialysis (HD) patients. However, the prognostic implications of trends in body temperature (BT) in this population have not yet been studied. The aim of this study was to assess the relationship between trends in BT and outcome in incident HD patients.

METHODS

Six thousand seven hundred and forty-two incident HD patients without thyroid disease from the Renal Research Institute were followed for 1 year. Patients were divided into tertiles of initial pre-dialysis BT (Tertile 1: ≤ 36.47°C, Tertile 2: > 36.47 to 36.71°C and Tertile 3: > 36.7°C) and further classified according to the change in BT (increased: > 0.01°C/month, decreased: less than -0.01°C/month and stable, with change between - 0.01 and + 0.01°C/month) during the first year of treatment. The reference group is Tertile 2 of initial temperature with stable BT. Cox regression was used for survival analyses. Analyses were repeated for patients who survived the first year and were treated for ≥ 1 month in Year 2.

RESULTS

BT decreased in 2903 patients, remained stable in 2238 patients and increased in 1601 patients. After adjustment for multiple risk factors, hazard ratios (HRs) for mortality were higher for those groups in whom, irrespective of the initial BT, BT increased or declined, as compared to the reference group during follow-up (HR between 1.46 and 2.27).

CONCLUSIONS

The best survival was observed in the group with the highest BT at baseline and stable BT during the follow-up period (HR 0.50).

Feeling too hot or cold after breast cancer: is it just a nuisance or a potentially important prognostic factor?

There is widespread recognition among both patients and caregivers that breast cancer patients often experience debilitating deficiencies in their ability to achieve thermal comfort, feeling excessively hot or cold under circumstances when others are comfortable. However, this symptom receives little clinical or scientific attention beyond identification and testing of drugs that minimise menopausal-like symptoms. Could some of these symptoms represent an important prognostic signal? Could thermal discomfort be among other cytokine-driven sickness behaviour symptoms seen in many breast cancer patients? While the literature reveals a strong link between treatment for breast cancer and some menopausal vasomotor symptoms (e.g. hot flashes also known as "hot flushes"), there is little data on quantitative assessment of severity of different types of symptoms and their possible prognostic potential. However, recent, intriguing studies indicating a correlation between the presence of hot flashes and reduced development of breast cancer recurrence strongly suggests that more study on this topic is needed. In comparison to reports on the phenomenon of breast cancer-associated hot flashes, there is essentially no scientific study on the large number of women who report feeling excessively cold after breast cancer treatment. Since similar acquired thermal discomfort symptoms can occur in patients with cancers other than breast cancer, there may be as yet unidentified cancer- or treatment-driven factor related to temperature dysregulation. In general, there is surprisingly little information on the physiological relationship between body temperature regulation, vasomotor symptoms, and cancer growth and progression. The goal of this article is twofold: (1) to review the scientific literature regarding acquired deficits in thermoregulation among breast cancer survivors and (2) to propose some speculative ideas regarding the possible basis for thermal discomfort among some of these women. Specifically, we suggest a potential association with excessive pro-inflammatory cytokine activity, similar to other cytokine-driven symptoms experienced after breast cancer, including fatigue and depression. We highlight the similarity of some breast cancer-associated thermal discomfort symptoms to those which occur during fever, suggesting the possibility that there may be common underlying changes in pro-inflammatory cytokine activity in both conditions. We anticipate that this contribution will stimulate additional scientific interest among researchers in identifying potential mechanisms and prognostic significance of this under-studied aspect of breast cancer biology and survivorship.

Measurement of body temperature in adult patients: comparative study of accuracy, reliability and validity of different devices

BACKGROUND AND AIMS

We compared a range of alternative devices with core body temperature measured at the pulmonary artery to identify the most valid and reliable instrument for measuring temperature in routine conditions in health services.

METHODS

201 patients from the intensive care unit of the Candelaria University Hospital, Canary Islands, admitted to hospital between April 2006 and July 2007. All patients (or their families) gave informed consent. Readings from gallium-in-glass, reactive strip and digital in axilla, infra-red ear and frontal thermometers were compared with the pulmonary artery core temperature simultaneously. External factors suspected of having an influence on the differences were explored. The cut-off point readings for each thermometer were fixed for the maximum negative predictive value in comparison with the core temperature. The validity, reliability, accuracy, external influence, the waste they generated, ease of use, speed, durability, security, comfort and cost of each thermometer was evaluated. An ad hoc overall valuation score was obtained from these parameters for each instrument.

RESULTS

For an error of ± 0.2°C and concordance with respect to fever, the gallium-in-glass thermometer gave the best results. The largest area under the receiver operating characteristic (ROC) curve is obtained by the digital axillar thermometer with probe (0.988 ± 0.007). The minimum difference between readings was given by the infrared ear thermometer, in comparison with the core temperature (-0.1 ± 0.3°C). Age, weight, level of conscience, male sex, environmental temperature and vaso-constrictor medication increases the difference in the readings and fever treatment reduces it, although this is not the same for all thermometers. The compact digital axillar thermometer and the digital thermometer with probe obtained the highest overall valuation score.

CONCLUSION

If we only evaluate the aspects of validity, reliability, accuracy and external influence, the best thermometer would be the gallium-in-glass after 12 min. The gallium-in-glass thermometer is less accurate after only 5 min in comparison with the reading taken after being placed for 12 min. If we add the evaluation of waste production, ease-of-use, speed, durability, security, patient comfort and costs, the thermometers that obtain the highest score are the compact digital and digital with probe in right axilla.

Circadian temperature variation and ageing

In the present paper, an attempt is made to summarize current knowledge concerning the daily body temperature rhythm and its age-dependent alterations. Homeostatic and circadian control mechanisms are considered. Special attention is paid to the circadian system, as the mechanisms of autonomic control are the topic of another contribution to this special issue. Also, the interactions of the core body temperature rhythm with other circadian functions are discussed in detail as they constitute an essential part of the internal temporal order of living systems and thus guarantee their optimal functioning. In the second part of the paper, age-dependent changes in the circadian body temperature rhythm and their putative causes, considering circadian and homeostatic components, are described. Consequences for health and fitness and some possibilities to prevent adverse effect are mentioned in the final section.