scholarly journals Comparison of zero heat flux and double sensor thermometers during spinal anaesthesia: a prospective observational study

2022 ◽  
Author(s):  
Sirkka-Liisa Lauronen ◽  
Maija-Liisa Kalliomäki ◽  
Jarkko Kalliovalkama ◽  
Antti Aho ◽  
Heini Huhtala ◽  
...  
Keyword(s):  
Heat Flux ◽  
Core Temperature ◽  
Spinal Anaesthesia ◽  
Prospective Observational Study ◽  
Repeated Measurements ◽  
Mean Difference ◽  
Concordance Correlation ◽  
Limits Of Agreement ◽  
Non Invasive ◽  
The Mean

AbstractBecause of the difficulties involved in the invasive monitoring of conscious patients, core temperature monitoring is frequently neglected during neuraxial anaesthesia. Zero heat flux (ZHF) and double sensor (DS) are non-invasive methods that measure core temperature from the forehead skin. Here, we compare these methods in patients under spinal anaesthesia. Sixty patients scheduled for elective unilateral knee arthroplasty were recruited and divided into two groups. Of these, thirty patients were fitted with bilateral ZHF sensors (ZHF group), and thirty patients were fitted with both a ZHF sensor and a DS sensor (DS group). Temperatures were saved at 5-min intervals from the beginning of prewarming up to one hour postoperatively. Bland–Altman analysis for repeated measurements was performed and a proportion of differences within 0.5 °C was calculated as well as Lin`s concordance correlation coefficient (LCCC). A total of 1261 and 1129 measurement pairs were obtained. The mean difference between ZHF sensors was 0.05 °C with 95% limits of agreement − 0.36 to 0.47 °C, 99% of the readings were within 0.5 °C and LCCC was 0.88. The mean difference between ZHF and DS sensors was 0.33 °C with 95% limits of agreement − 0.55 to 1.21 °C, 66% of readings were within 0.5 °C and LCCC was 0.59. Bilaterally measured ZHF temperatures were almost identical. DS temperatures were mostly lower than ZHF temperatures. The mean difference between ZHF and DS temperatures increased when the core temperature decreased.Trial registration: The study was registered in ClinicalTrials.gov on 13th May 2019, Code NCT03408197.

scholarly journals Evaluation of Inter-System Variability in Liver Stiffness Measurements

2018 ◽  
Vol 40 (01) ◽  
pp. 64-75 ◽  
Author(s):  
Giovanna Ferraioli ◽  
Annalisa De Silvestri ◽  
Raffaella Lissandrin ◽  
Laura Maiocchi ◽  
Carmine Tinelli ◽  
...  
Keyword(s):  
Shear Wave ◽  
Liver Stiffness ◽  
Shear Wave Elastography ◽  
Mean Difference ◽  
Observer Agreement ◽  
Concordance Correlation ◽  
Limits Of Agreement ◽  
Inter Observer Variability ◽  
System Variability ◽  
The Mean

Abstract Aim The primary aim of this study was to determine the inter-system variability of liver stiffness measurements (LSMs) in patients with varying degrees of liver stiffness. The secondary aim was to determine the inter-observer variability of measurements. Materials and Methods 21 individuals affected by chronic hepatitis C and 5 healthy individuals were prospectively enrolled. The assessment of LSMs was performed using six ultrasound (US) systems, four of which with point shear wave elastography (p-SWE) and two with 2 D shear wave elastography (2D-SWE) systems. The Fibroscan (Echosens, France) was used as the reference standard. Four observers performed the measurements in pairs (A-B, C-D). The agreement between different observers or methods was calculated using Lin’s concordance correlation coefficient. The Bland-Altman limits of agreement (LOA) were calculated as well. Results There was agreement above 0.80 for all pairs of systems. The mean difference between the values of the systems with 2D-SWE technique was 1.54 kPa, whereas the maximum mean difference between the values of three out of four systems with the pSWE technique was 0.79 kPa. The intra-patient concordance for all systems was 0.89 (95 % CI: 0.83 – 0.94). Inter-observer agreement was 0.96 (95 % CI: 0.94 – 0.98) for the pair of observers A-B and 0.93 (95 % CI: 0.89 – 0.96) for the pair of observers C-D. Conclusion The results of this study show that the agreement between LSMs performed with different US systems is good to excellent and the overall inter-observer agreement in “ideal conditions” is above 0.90 in expert hands.

Rectal and Bladder Temperatures vs Forehead Core Temperatures Measured With SpotOn Monitoring System

2018 ◽  
Vol 27 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Hildy M. Schell-Chaple ◽  
Kathleen D. Liu ◽  
Michael A. Matthay ◽  
Kathleen A. Puntillo
Keyword(s):  
Heat Flux ◽  
Critical Care ◽  
Intensive Care ◽  
Body Temperature ◽  
Urinary Bladder ◽  
Core Temperature ◽  
Continuous Monitoring ◽  
Limits Of Agreement ◽  
The Mean ◽  
Critical Care Patients

BackgroundMethods and frequency of temperature monitoring in intensive care unit patients vary widely. The recently available SpotOn system uses zero-heat-flux technology and offers a noninvasive method for continuous monitoring of core temperature of critical care patients at risk for alterations in body temperature.ObjectiveTo evaluate agreement between and precision of a zero-heat-flux thermometry system (SpotOn) and continuous rectal and urinary bladder thermometry during fever and defervescence in adult patients in intensive care units.MethodsProspective comparison of SpotOn vs rectal and urinary bladder thermometry in eligible patients enrolled in a randomized clinical trial on the effect of acetaminophen on core body temperature and hemodynamic status.ResultsA total of 748 paired temperature measurements from 38 patients who had both SpotOn monitoring and either continuous rectal or continuous bladder thermometry were analyzed. Temperatures during the study were from 36.6°C to 39.9°C. The mean difference for SpotOn compared with bladder thermometry was −0.07°C (SD, 0.24°C; 95% limits of agreement, ± 0.47°C [−0.54°C, 0.40°C]). The mean difference for SpotOn compared with rectal thermometry was −0.24°C (SD, 0.29°C; 95% limits of agreement, ± 0.57°C [−0.81°C, 0.33°C]). Most differences in temperature between methods were within ± 0.5°C in both groups (96% bladder and 85% rectal).ConclusionsThe SpotOn thermometry system has excellent agreement and good precision and is a potential alternative for noninvasive continuous monitoring of core temperature in critical care patients, especially when alternative methods are contraindicated or not available.

scholarly journals Accuracy of zero-heat-flux thermometry and bladder temperature measurement in critically ill patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anselm Bräuer ◽  
Albulena Fazliu ◽  
Thorsten Perl ◽  
Daniel Heise ◽  
Konrad Meissner ◽  
...  
Keyword(s):  
Heat Flux ◽  
Critically Ill ◽  
Core Temperature ◽  
Critically Ill Patients ◽  
Gold Standard ◽  
Prospective Observational Study ◽  
Standard Of Care ◽  
Limits Of Agreement ◽  
Blood Temperature ◽  
Bladder Temperature

AbstractCore temperature (TCore) monitoring is essential in intensive care medicine. Bladder temperature is the standard of care in many institutions, but not possible in all patients. We therefore compared core temperature measured with a zero-heat flux thermometer (TZHF) and with a bladder catheter (TBladder) against blood temperature (TBlood) as a gold standard in 50 critically ill patients in a prospective, observational study. Every 30 min TBlood, TBladder and TZHF were documented simultaneously. Bland–Altman statistics were used for interpretation. 7018 pairs of measurements for the comparison of TBlood with TZHF and 7265 pairs of measurements for the comparison of TBlood with TBladder could be used. TBladder represented TBlood more accurate than TZHF. In the Bland Altman analyses the bias was smaller (0.05 °C vs. − 0.12 °C) and limits of agreement were narrower (0.64 °C to − 0.54 °C vs. 0.51 °C to – 0.76 °C), but not in clinically meaningful amounts. In conclusion the results for zero-heat-flux and bladder temperatures were virtually identical within about a tenth of a degree, although TZHF tended to underestimate TBlood. Therefore, either is suitable for clinical use.German Clinical Trials Register, DRKS00015482, Registered on 20th September 2018, http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00015482.

Biochemical Aspects and Clinical Perspectives of Continuous Urea Monitoring in Plasma Ultrafiltrate: Preliminary Results of a Multicenter Study

1995 ◽  
Vol 18 (9) ◽  
pp. 544-547 ◽  
Author(s):  
G. Colasanti ◽  
G. Arrigo ◽  
A. Santoro ◽  
S. Mandolfo ◽  
C. Tetta ◽  
...  
Keyword(s):  
Laboratory Method ◽  
Mean Difference ◽  
Limits Of Agreement ◽  
Laboratory Plasma ◽  
Plasma Urea ◽  
Urea Kinetics ◽  
On Line ◽  
The Mean ◽  
Plasma Urea Concentration

We tested a new biosensor for urea monitoring in the ultrafiltrate during PFD in a group of 5 hemodialyzed stable patients. The inspection of the UF-urea profile reflects the dynamical changes of the plasma urea concentration during diffusive dialysis and allows the fitting of the main mathematical models of urea kinetics. The biosensor efficiency was 98.4% on average (SD: 1.5%) at Uf fluxes varying from 45 to 55 ml/min (mean: 51 ml/min; SD: 3.2) and at Uf-urea concentrations varying from 23 to 165 mg/dl. The mean difference between Uf-urea determined by the laboratory method and Uf-urea assayed by the biosensor was -1.07 mg/dl and the 95% confidence interval ranged from -2.01 to 0.13 mg/dl. The mean difference between laboratory plasma urea and Uf-urea from the biosensor was on average -1.9 mg/dl and the estimated limits of agreement with a confidence of 95% were -3.16 and 0.64 mg/dl. Comparison between kinetic models and experimental profiles of plasma urea decrease, evaluations of recirculation and post-dialytic rebound, the role of Kt/V on-line during dialysis were the preliminary clinical applications of this biosensor.

scholarly journals A prospective observational study testing liquid crystal phase change type thermometer placed on skin against oesophageal/pharyngeal placed thermometers in participants undergoing general anesthesia

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
G. Simpson ◽  
R. N. Rodseth
Keyword(s):  
Observational Study ◽  
Surface Temperature ◽  
General Anaesthesia ◽  
Prospective Observational Study ◽  
Standard Of Care ◽  
Skin Surface ◽  
Temperature Monitoring ◽  
Skin Surface Temperature ◽  
Limits Of Agreement ◽  
Non Invasive

Abstracts Background Patient outcomes are influenced by intraoperative temperature management. Oesophageal/pharyngeal temperature monitoring is the standard of care at our institute but is not well tolerated in awake patients. Many non-invasive temperature monitors have been studied. Only the TraxIt® Wearable Children’s Underarm Thermometer which contains liquid crystals that undergo phase changes according to temperature is available at our institution. We tested these non-invasive monitors against our standard of care which is the oesophageal/pharyngeal temperature monitor. Methods We conducted a prospective observational study of 100 patients receiving general anaesthesia for elective surgery. Patients were eligible for inclusion if they were ≥ 18 years old, were planned to have a general anaesthetic > 60 min during which no body cavity (chest or abdomen) would be opened. Patient temperature was measured with an oesophageal/pharyngeal thermistor probe and skin surface temperature monitors placed over the forehead, in the axilla, over the sternum, and behind the ear (over major vessels to the brain). Temperatures were recorded and then analysed using Altman-Bland plots. Pre-determined clinically relevant limits of agreement were set at −/+ 0.5 °C. Results From the 100 patients we collected 500 data points for each monitor with an average monitoring time of 102 min (30–300 min) across a range of surgical procedures. None of the skin surface temperature monitors achieved the pre-determined limits of agreement and results were impacted by the use of a forced air warmer. Conclusion The TraxIt® Wearable Children’s Underarm Thermometers are not suitable for temperature monitoring during general anaesthesia.

Convergent validation of a questionnaire to assess the mode and frequency of commuting to and from school

2017 ◽  
Vol 45 (6) ◽  
pp. 612-620 ◽  
Author(s):  
Palma Chillón ◽  
Manuel Herrador-Colmenero ◽  
Jairo H. Migueles ◽  
Verónica Cabanas-Sánchez ◽  
Jorge R. Fernández-Santos ◽  
...  
Keyword(s):  
Physical Activity ◽  
Convergent Validity ◽  
Vigorous Physical Activity ◽  
Mean Difference ◽  
Activity Levels ◽  
Limits Of Agreement ◽  
Google Maps ◽  
Journey Time ◽  
The Mean ◽  
Convergent Validation

Aims: The purposes of this research were to study the convergent validity of the Mode and Frequency of Commuting To and From School Questionnaire using objectively assessed steps and time spent in different physical activity intensities and to compare the self-reported versus objective journey time in Spanish youths. Methods: Three hundred and eighty-nine Spanish youth aged 7–19 years were asked to complete the questionnaire and wore an accelerometer for five days. The objective commuting distance and time from home to school were estimated using Google MapsTM. Results: There were significant differences between passive and walking participants on step numbers, sedentary time and physical activity levels (except for vigorous physical activity in children). For children, a mean difference of −4.03 minutes between objective measured and self-reported journey time was found (95% limits of agreement were 13.55 and −21.60 minutes). For adolescents, the mean difference was −1.39 minutes (95% limits of agreement were 15.23 and −18.02 minutes). Conclusions: The findings indicated that the Mode of Commuting To and From School Questionnaire showed a convergent validity to assess this behaviour in Spanish youths. Self-reported journey time for walking is comparable to Google MapsTM in adolescents but not in children.

scholarly journals Resting energy expenditure measured longitudinally following hip fracture compared to predictive equations: is an injury adjustment required?

2005 ◽  
Vol 94 (6) ◽  
pp. 976-982 ◽  
Author(s):  
Michelle D. Miller ◽  
Lynne A. Daniels ◽  
Elaine Bannerman ◽  
Maria Crotty
Keyword(s):  
Hip Fracture ◽  
Energy Expenditure ◽  
Total Energy ◽  
Physiological Stress ◽  
Resting Energy Expenditure ◽  
Mean Difference ◽  
Limits Of Agreement ◽  
Predictive Equations ◽  
The Mean ◽  
Resting Energy

The present study measuring resting energy expenditure (REE; kJ/d) longitudinally using indirect calorimetry in six elderly women aged ≥70 years following surgery for hip fracture, describes changes over time (days 10, 42 and 84 post-injury) and compares measured values to those calculated from routinely applied predictive equations. REE was compared to REE predicted using the Harris Benedict and Schofield equations, with and without accounting for the theoretical increase in energy expenditure of 35 % secondary to physiological stress of injury and surgery. Mean (95 % CI) measured REE (kJ/d) was 4704 (4354, 5054), 4090 (3719, 4461) and 4145 (3908, 4382) for days 10, 42 and 84, respectively. A time effect was observed for measured REE,P=0·003. Without adjusting for stress the mean difference and 95 % limits of agreement for measured and predicted REE (kJ/kg per d) for the Harris Benedict equation were 1 (−9, 12), 10 (2, 18) and 9 (1, 17) for days 10, 42 and 84, respectively. The mean difference and 95 % limits of agreement for measured and predicted REE (kJ/kg per d) for the Schofield equation without adjusting for stress were 8 (−3, 19), 16 (6, 26) and 16 (10, 22) for days 10, 42 and 84, respectively. After adjusting for stress, REE predicted from the Harris Benedict or Schofield equations overestimated measured REE by between 38 and 69 %. Energy expenditure following fracture is poorly understood. Our data suggest REE was relatively elevated early in recovery but declined during the first 6 weeks. Using the Harris Benedict or Schofield equations adjusted for stress may lead to overestimation of REE in the clinical setting. Further work is required to evaluate total energy expenditure before recommendations can be made to alter current practice for calculating theoretical total energy requirements of hip fracture patients.

Inter- and intra-operator variability associated with extracapsular suture tensioning

2012 ◽  
Vol 25 (06) ◽  
pp. 472-477 ◽  
Author(s):  
E. A. Buffa ◽  
A. M. Marchevsky ◽  
J. Heller ◽  
A. P. Moores ◽  
M. Farrell ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Cruciate Ligament ◽  
Mean Difference ◽  
Marked Variation ◽  
Limits Of Agreement ◽  
Cranial Cruciate Ligament ◽  
Suture Tension ◽  
Clinical Consequences ◽  
The Mean ◽  
The Difference

SummaryObjectives: To determine inter- and intra- operator variability associated with extracapsular suture tensioning as performed during lateral fabello-tibial suture placement.Study design: Ex vivo study.Methods: Fifteen Greyhound cadaveric pelvic limbs were prepared by cutting the cranial cruciate ligament and placing an extracapsular fabello-tibial suture. On two occasions, three surgeons tensioned the extracapsular suture of each stifle. Stifles were returned to 135 degrees of flexion and the suture tension was measured using a commercially available suture tensioner with inbuilt tensiometer.Statistical analysis: Intra-operator and inter-operator agreement were assessed using the limits of agreement method. A linear mixed effects model was specified to assess the effect of operator, repeated estimates and stifle order on tension applied.Results: The mean difference within the three operators ranged from 0 to 14.7N. With 95% limits of agreement, on most occasions for all three operators, the difference was between –31.7 and 41.0 N. The mean difference between the three operators ranged from 6.0 to 30.7 N. With 95% limits of agreement, on most occasions the difference between operators was between –25.6 and 62.5 N.Clinical significance: Marked variation exists in the tension applied during fabello- tibial suture application, both within and between surgeons. This variation may lead to inconsistent clinical outcomes. Further studies are required to determine the clinical consequences of this marked variation in extracapsular suture tensioning.

scholarly journals Comparison of Two Techniques of Superior Vena Cava Flow Measurement in Preterm Infants With Birth Weight <1,250 g in the Transitional Period—Prospective Observational Cohort Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Jan Miletin ◽  
Zbynek Stranak ◽  
Niamh Ó Catháin ◽  
Jan Janota ◽  
Jana Semberova
Keyword(s):  
Birth Weight ◽  
Flow Measurement ◽  
Superior Vena ◽  
Vena Cava ◽  
Observational Cohort Study ◽  
Mean Difference ◽  
Prospective Observational Cohort Study ◽  
Limits Of Agreement ◽  
Observational Cohort ◽  
The Mean

Objectives: Superior Vena Cava (SVC) flow in neonates measured by the standard approach has been validated by different groups around the world. The modified SVC flow measurement technique was recently suggested. The aim of our study was to evaluate standard and modified technique of echocardiography SVC flow measurement in a cohort of extremely preterm neonates in the immediate postnatal period.Methods: Prospective, observational cohort study in a level III neonatal center. Infants with birth weight &lt;1,250 g were eligible for enrolment. SVC flow was measured by echocardiography using standard and modified methods at 6, 18 and 36 h of age. Our primary outcome was equivalency (using raw bounds of −20 to +20 mL/kg/min difference between the paired measurements), agreement and correlation between standard and modified methods of the SVC flow measurements.Results: Thirty-nine infants were enrolled. The mean gestational age of the cohort was 27.4 (SD 2.1) weeks of postmenstrual age, the mean birth weight was 0.95 kg (SD 0.2). The measurements at 6 and 36 h of age were equivalent as defined in the design of the study (p = 0.003 and p = 0.004 respectively; raw bounds −20 to +20 mL/kg/min). At 6 h of age the mean difference (bias) between the measurements was −0.8 mL/kg/min with 95% limits of agreement −65.0 to 63.4 mL/kg/min. At 18 h of age, the mean difference (bias) between the measurements was +9.5 mL/kg/min, with 95% limits of agreement −79.6 to 98.7 mL/kg/min. At 36 h of age the mean difference (bias) between the measurements was −2.2 mL/kg/min with 95% limits of agreement −73.4 to 69.1 mL/kg/min. There was a weak, but statistically significant correlation between the standard and modified method at 6 h of age (r = 0.39, p = 0.04).Conclusion: Both SVC flow echocardiography measurement techniques yielded clinically equivalent results, however due to wide limits of agreement and poor correlation they do not seem to be interchangeable.

scholarly journals Transcutaneous Bilirubin Measurements Can Be Used to Measure Bilirubin Levels during Phototherapy

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Saad Abdullah Alsaedi
Keyword(s):  
Prospective Observational Study ◽  
Serum Bilirubin ◽  
Linear Regression Analysis ◽  
Mean Difference ◽  
Total Serum ◽  
Term Infants ◽  
Transcutaneous Bilirubin ◽  
Term Newborns ◽  
The Mean ◽  
Mean Differences

Objective. To determine whether transcutaneous bilirubin measurements (TcB) before and during phototherapy taken from covered skin during phototherapy correlate with total serum bilirubin (TSB) levels.Study Design. In this prospective observational study, healthy term newborns who required TSB measurements were included. TcB measurements were taken from the forehead before starting and during phototherapy using the BiliChek device. Before starting phototherapy, part of the forehead was covered. Blood for TSB measurement was collected within 5 minutes of TcB measurements. Correlations and mean differences between TcB and TSB before and during phototherapy were calculated.Result. Paired TSB and TcB measurements before and during phototherapy in 151 newborns were performed. The mean gestational age was 38.8 weeks and birth weight was 3.1 kg; 53% were male. Before starting phototherapy, TSB and TcB were183.8±41.6and 190.5 ± 43 μmol/l, respectively. During phototherapy, TSB and TcB were191.8±39.4and187.8±45.3 μmol/l, respectively. Linear regression analysis showed a significant correlation between TcB and TSB before starting phototherapy and during phototherapy (r: 0.85;p<0.001andr: 80.0;p<0.001), respectively. Before starting phototherapy, the mean difference between TSB and TcB was6.2±23.2 μmol/l, with a 95% CI of −39.3 to 51.7 μmol. During phototherapy, the mean difference was −2.8±23.5 μmol/l, with a 95% CI of −48.9 to 43.3 μmol/l.Conclusion. TcB measurements from covered skin in jaundiced term infants during phototherapy correlate with TSB and can be used to monitor bilirubin levels during phototherapy.

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