Bladder Temperature Research Articles

Ultrafast Cooling With Total Liquid Ventilation Mitigates Early Inflammatory Response and Offers Neuroprotection in aPorcine Model of Cardiac Arrest.

Brain injury is one of the most serious complications after cardiac arrest (CA). To prevent this phenomenon, rapid cooling with total liquid ventilation (TLV) has been proposed in small animal models of CA (rabbits and piglets). Here, we aimed to determine whether hypothermic TLV can also offer neuroprotection and mitigate cerebral inflammatory response in large animals. Anesthetized pigs were subjected to 14 minutes of ventricular fibrillation followed by cardiopulmonary resuscitation. After return of spontaneous circulation, animals were randomly subjected to normothermia (control group, n=8) or ultrafast cooling with TLV (TLV group, n=8). In the latter group, TLV was initiated within a window of 15 minutes after return of spontaneous circulation and allowed to reduce tympanic, esophageal, and bladder temperature to the 32 to 34 °C range within 30 minutes. After 45 minutes of TLV, gas ventilation was resumed, and hypothermia was maintained externally until 3 hours after CA, before rewarming using heat pads (0.5 °C-1 °C/h). After an additional period of progressive rewarming for 3 hours, animals were euthanized for brain withdrawal and histological analysis. At the end of the follow-up (ie, 6 hours after CA), histology showed reduced brain injury as witnessed by the reduced number of Fluroro-Jade C-positive cerebral degenerating neurons in TLV versus control. IL (interleukin)-1ra and IL-8 levels were also significantly reduced in the cerebrospinal fluid in TLV versus control along with cerebral infiltration by CD3+ cells. Conversely, circulating levels of cytokines were not different among groups, suggesting a discrepancy between local and systemic inflammatory levels. Ultrafast cooling with TLV mitigates neuroinflammation and attenuates acute brain lesions in the early phase following resuscitation in large animals subjected to CA.

Comparison of continuous temperature measurement methods in the intensive care unit: standard bladder catheter measurements versus non-invasive transcutaneous sensors.

The purpose of this study was to compare a wearable system for body core temperature measurement versus bladder and tympanic thermometers in an intensive care setting. The question was, if continuous non-invasive sensors in the intensive care unit represent an alternative to current standard methods of invasive continuous bladder temperature measurement methods?Between May and September 2023, a comparative investigation involving 112 patients was conducted in a 20-bed surgical intensive care unit to assess various temperature probes, including those placed in the tympanic tube, bladder, and skin. To achieve this, a wireless non-invasive sensor system provided by greenTEG AG, Switzerland, was affixed to different body locations (clavicular and lateral chest) of each catheterized patient (equipped with a temperature probe) admitted to the intensive care unit. Furthermore, tympanic temperatures were recorded at specified intervals. The measurement duration ranged from a minimum of six hours to a maximum of six days, resulting in the analysis of a total of 355 simultaneous temperature measurements.In this study, a wearable temperature measurement system attached to two different body sites revealed a consistent negative bias compared to bladder temperature. In addition, the measurements were particularly influenced by body constitution. The tested system in all patients showed a mean absolute error (MAE) of 0.45°C for the lateral chest and 0.50°C for the clavicular position. Tympanic measurements had a mean absolute error of 0.35°C. In patients with body mass index (BMI) ≥ 25 the MAE increased to 0.5°C for the lateral chest and 0.56°C for the clavicular position. In contrast, the tympanic measurement had a reduced MAE of 0.32°C, which is well below this threshold when compared to bladder measurements.In conclusion the investigated system did not meet the clinically relevant acceptance criteria and showed low precision in correctly identifying fever episodes compared to invasive temperature probes, however its main advantage lies in its continuity and non-invasiveness. This makes it a potential alternative to intermittent tympanic measurement devices. In this study we were able to show, that in at least one subset of patients, the non-invasive and continuous device demonstrated a precision comparable to tympanic measurements.The accuracy of all non-invasive methods was lower than in previous studies, suggesting that the use of bladder temperature as reference and user related variations may have introduced additional errors.

Comparison of Wireless Continuous Axillary and Core Temperature Measurement after Major Surgery.

Temperature is considered one of the primary vital signs for detection of complications such as infections. Continuous wireless real-time axillary temperature monitoring is technologically feasible at the general ward, but no clinical validation studies exist. This study compared axillary temperature with a urinary bladder thermometer in 40 major abdominal postoperative patients. The primary outcome was changes in axillary temperature registrations. Secondary outcomes were mean bias between the urinary bladder and the axillary temperatures. Intermittent frontal and tympanic temperature recordings were also collected. Forty patients were monitored for 50 min with an average core temperature of 36.8 °C. The mean bias was -1.0 °C (LoA -1.9 to -0) after 5 min, and -0.8 °C (LoA -1.6 to -0.1) after 10 min when comparing the axillary temperature with the urinary bladder temperature. After 20 min, the mean bias was -0.6 °C (LoA -1.3-0.1). During upper arm abduction, the axilla temperature was reduced to -1.6 °C (LoA -2.9 to -0.3) within 1 min. Temporal skin temperature measurement had a resulted in a mean bias of -0.1 °C (LOA -1.1 to -1.0) compared with central temperature. Compared with the mean tympanic temperature, it was -0.1 °C (LoA -0.9 to -1.0) lower than the urinay bladder temperature. Axillary temperature increased with time, reaching a mean bias of 1 °C between axillary and core temperature within 5 min. Opening the axillary resulted in rapidly lower temperature recordings. These findings may aid in use and designing corrections for continuous axillary temperature monitoring.

Accuracy of a zero-heat-flux thermometer in cardiac surgery, a prospective, multicentre, method comparison study

Accurate measurement of core temperature is of utmost importance during on-pump cardiac surgery, for detection of hypothermia before cardiopulmonary bypass (CPB), guidance of temperature management on CPB, active rewarming on CPB and guidance of warming therapy after CPB. Most temperature measurement methods are known to become inaccurate during rapid changes in core temperature and suffer from delayed detection of temperature changes. Zero-heat-flux temperature (ZHF) measurement from the lateral forehead may be an alternative, non-invasive method quantifying the core temperature. A prospective, observational, multicentre study was conducted in one hundred patients scheduled for on-pump coronary artery bypass grafting. Core temperatures were measured every minute by two zero-heat-flux thermometer (SpotOn™) and a bladder thermometer and a pulmonary artery catheter (PAC) in the period after induction of anesthesia until CPB. Accuracy and precision of both methods were compared against core temperature measured in the pulmonary artery using the method of Bland and Altman. A high accuracy (around 0.1 °C) and a very good precision (Limits of agreement (LoA) − 0.6; 0.4 °C) were found between zero-heat-flux thermometer and core temperature measured by PAC. Among the two ZHF thermometers the bias was negligible (− 0.003 °C) with narrow LoA of − 0.42 °C and 0.41 °C. In contrast, bias between bladder temperature and PAC temperature was large (0.51 °C) with corresponding LoA of − 0.06 °C and 1.1 °C. ZHF thermometers are in contrast to bladder temperature a reliable core temperature monitor in cardiac surgery during the period after induction of anestesia until CPB. The zero-heat-flux method can provide clinicians reliably with continuous and non-invasive measurements of core temperature in normothermic and mild hypothermic temperature ranges and therefore can be helpful to guide temperature management.

Influencing factors of bladder temperature measured by temperature-sensing urinary catheter in patients with massive burns

Influencing factors of bladder temperature measured by temperature-sensing urinary catheter in patients with massive burns

Unveiling the nexus of postoperative fever and delirium in cardiac surgery: identifying predictors for enhanced patient care.

Postoperative delirium (POD) is a significant complication observed in cardiac surgery patients, characterized by acute cognitive decline, fluctuating mental status, consciousness impairment, and confusion. Despite its impact, POD often goes undiagnosed. Postoperative fever, a common occurrence after cardiac surgery, has not been comprehensively studied in relation to delirium. This study aims to identify perioperative period factors associated with POD in patients undergoing cardiopulmonary bypass, with the potential for implementing preventive interventions. In a prospective observational study conducted between February 2023 and April 2023 at the Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, a total of 232 patients who underwent cardiac surgery were enrolled. POD assessment utilized the Confusion Assessment Method for the ICU (CAM-ICU), while high fever was defined as a bladder temperature exceeding 39°C. Statistical analysis included univariate and multivariate analyses, logistic regression, nomogram development, and internal validation. The overall incidence of postoperative delirium was found to be 12.1%. Multivariate analysis revealed that postoperative lactate levels [odds ratio (OR) = 1.787], maximum temperature (OR = 11.290), and cardiopulmonary bypass time (OR = 1.015) were independent predictors of POD. A predictive nomogram for POD was developed based on these three factors, demonstrating good discrimination and calibration. The prediction model exhibited a C-statistic value of 0.852 (95% CI, 0.763-0.941), demonstrating excellent discriminatory power. Sensitivity and specificity, based on the area under the receiver operating characteristic (AUROC) curve, were 91.2% and 67.9%, respectively. This study underscores the high prevalence of POD in cardiac surgery patients and identifies postoperative lactate levels, cardiopulmonary bypass duration, and postoperative fever as independent predictors of delirium. The association between postoperative fever and POD warrants further investigation. These findings have implications for implementing preventive strategies in high-risk patients, aiming to mitigate postoperative complications and improve patient outcomes.

Abstract 15937: The Impact of Social Vulnerability on Aortic Arch Surgery

Introduction: Socioeconomic status is a known factor influencing morbidity and mortality. The CDC’s social vulnerability index (SVI) quantifies neighborhood-level vulnerability. Although high SVI has been associated with adverse outcomes in trauma, CABG, and AAA repair, its impact on aortic arch surgery remains unknown. Hypothesis: In total aortic arch (TAR) and hemiarch (HAR) replacement, higher SVI will correlate with increased comorbidities, surgical acuity, and post-operative morbidity and mortality. Methods: This single-center retrospective study examined patients undergoing HAR and TAR performed for aortic aneurysm and/or dissection between 2010 and 2022. SVI was calculated by patient residential ZIP code. The cohort was stratified into three groups: SVI<0.33, SVI 0.33-0.66, and SVI≥0.66. The primary endpoint was postoperative mortality, with control for confounding bias through multivariable logistic regression. Results: For 753 patients, higher SVI correlated with more baseline comorbidities and minority status. SVI was associated with dissection pathology (p=0.04) and urgent/emergent procedure (p=0.02). Higher SVI was associated with TAR (p=0.01), reflected by lower nadir bladder temperatures (p=0.01), longer cardiopulmonary bypass (p=0.02) and circulatory arrest times(p=0.01), and more coagulation product usage. High SVI patients had longer length of stay, higher rates of infection (p=0.01) and a trend towards increased stroke risk. SVI did not correlate with in-hospital or late mortality, confirmed by multivariable regression. Conclusion: Socially vulnerable patients, often from minority backgrounds, tend to have more comorbidities and present urgently or emergently with dissection pathology, requiring more extensive arch repair. Post-procedure, they have a higher risk of infection and a trend towards more stoke risk, but not higher rates of other adverse outcomes or increased mortality during or after hospital stay.

Abstract 15941: Efficacy of Frozen Elephant Trunk for Acute Type A Aortic Dissection

Objectives: There are various treatment strategies for acute type A aortic dissection (ATAAD). In our department, total arch replacement (TAR) using the Frozen Elephant Trunk (FET) is the standard technique for DeBakey type I, which has a patent false lumen, and we assessed the outcomes and postoperative complications. Methods: Of 71 consecutive patients who underwent surgical treatment for ATAAD at our department from October 2020 to May 2023, 42 patients were included, excluding 29 patients whose the descending aorta was thrombosed or not dissected. Results: Age 64±11 years, 30 male patients (71.4%). Preoperatively, cardiac tamponade was observed in 5 cases, malperfusion in 5 cases of head, 2 cases of coronary artery, 3 cases of celiac artery, 3 cases of superior mesenteric artery, 13 cases of renal artery, and 13 cases of lower limbs. The surgical procedures were ascending aortic replacement (AAR) in 6 cases (14.2%), partial arch replacement (PAR) in 2 cases (4.8%), TAR in 5 cases (11.9%), and TAR with FET in 29 cases (69.0%). The mean operation time was 304±70 minutes, the mean cardiopulmonary bypass time 168±45 minutes, the mean cardiac arrest time 100±26 minutes, the mean circulatory arrest time 42±8 minutes, and the mean minimum bladder temperature 26.1±1.4°C. There was no hospital death, and complications included new stroke in 2 patients (4.8%). The residual dissection was AAR5/6 (83.3%), PAR1/2 (50.0%), TAR5/5 (100%), and TAR with FET24/29 (82.8%), of which AAR5/5 (100%), PAR1/1 (100%), TAR2/5 (40.0%), and TAR with FET1/24 (4.2%) had residual dissection in the proximal descending aorta. There were 3 deaths (meningitis, cerebral hemorrhage, gastrointestinal hemorrhage) with a mean follow-up of 8.9±6.7 months. The only additional treatment was preemptive TEVAR in 1 case (2.4%) for residual dissection of proximal descending aorta of TAR with FET. There was no case of stent induced new entry. Conclusions: We consider the early results for ATAAD to be favorable. Furthermore, TAR with FET promotes good thrombosis and remodeling down to the proximal descending level, suggesting that FET may contribute to improved outcomes during follow-up period. Further clinical research on mid-term outcomes is needed.

Prospective comparative analysis of zero-heat-flux thermometer (SpotOn®) compared with tympanic thermometer and bladder thermometer in extremely aged patients undergoing lower extremity orthopedic surgery.

Thermoregulation is important for maintaining homeostasis in the body. It can be easily broken under anesthesia. An appropriate method for measuring core body temperature is needed, especially for elderly patients, because the efficiency of thermoregulation gradually decreases with age. Zero-heat-flux (ZHF) thermometry (SpotOn) is an alternative, noninvasive method for continuous temperature monitoring at the skin surface. The aim of this study was to examine the accuracy and feasibility of using the SpotOn sensor in lower extremity orthopedic surgery in elderly patients aged over 80 years by comparing a SpotOn sensor with 2 other reliable minimally invasive methods: a tympanic membrane thermometer and a bladder thermometer. This study enrolled 45 patients aged over 80 years who were scheduled to undergo lower extremity surgery. Body temperature was measured using a SpotOn sensor, a tympanic membrane thermometer and a bladder thermometer. Agreements between the SpotOn sensor and the other 2 methods were assessed using Bland and Altman plots for repeated measures adjusted for unequal numbers of measurements per patient. Compared with bladder temperature, bias and limits of agreement for SpotOn temperature were 0.07°C ± 0.58°C. Compared with tympanic membrane temperature, bias and limits of agreement for SpotOn temperature were -0.28°C ± 0.61°C. The 3M SpotOn sensor using the ZHF method for patients aged over 80 years undergoing lower extremity surgery showed feasible measurement value and sensitivity.

Zone 2 arch repair for acute type A dissection: Evolution from arch-first to proximal-first repair.

With growing experience of acute type A aortic dissection repair, Zone 2 arch repair has been advocated. The aim of this study is to compare the outcome between "proximal-first" and "arch-first" Zone 2 repair. From January 2015 to March 2023, 45 patients underwent Zone 2 arch repair out of 208 acute type A aortic dissection repairs: arch-first, N=19, and proximal-first technique, N=26, since January 2021. Indications were aortic arch or descending tear, complex dissection in neck vessels, cerebral malperfusion, or aneurysm of the aortic arch. The lowest bladder temperature was higher in the proximal-first technique (24.9 °C vs 19.7 °C, P<.001). Cardiopulmonary bypass (230 vs 177.5minutes, P<.001), myocardial ischemic (124 vs 91minutes, P<.001), and lower-body circulatory arrest (87 vs 28minutes, P<.001) times were shorter in the proximal-first technique. The arch-first group required more packed red blood cells (arch-first, 2 units vs proximal-first, 0 units, P=.048), platelets (arch-first, 4 units vs proximal-first, 2 units, P=.003), and cryoprecipitates (arch-first, 2 units vs proximal-first, 1 unit, P=.024). Operative mortality and major morbidities were higher in the arch-first group (57.9% vs 11.5%, P=.001). One-year survival was comparable (arch-first, 89.5% ± 7.0% vs proximal-first, 92.0% ± 5.5%, P=.739). Distal intervention was successfully performed in 5 patients (endovascular, N=3, and open repair, N=2). Zone 2 arch repair using the proximal-first technique for acute type A aortic dissection repair yields shorter lower-body ischemic time with a warmer core temperature, resulting in shorter cardiopulmonary bypass time, less blood product use, and fewer morbidities when compared with the arch-first technique.

Cardiopulmonary bypass management and risk of new-onset atrial fibrillation after cardiac surgery.

Cardiopulmonary bypass (CPB) management may potentially play a role in the development of new-onset atrial fibrillation (AF) after cardiac surgery. The aim of this study was to explore this potential association. Patients who underwent coronary artery bypass grafting and/or valvular surgery during 2016-2020 were included in an observational single-centre study. Data collected from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry and a local CPB database were merged. Associations between individual CPB variables (CPB and aortic clamp times, arterial and central venous pressure, mixed venous oxygen saturation, blood flow index, bladder temperature and haematocrit) and new-onset AF were analysed using multivariable logistic regression models adjusted for patient characteristics, comorbidities and surgical procedure. Out of 1999 patients, 758 (37.9%) developed new-onset AF. Patients with new-onset postoperative AF were older, had a higher incidence of previous stroke, worse renal function and higher EuroSCORE II and CHA2DS2-VASc scores and more often underwent valve surgery. Longer CPB time [adjusted odds ratio 1.05 per 10 min (95% confidence interval 1.01-1.08); P = 0.008] and higher flow index [adjusted odds ratio 1.21 per 0.2 l/m2 (95% confidence interval 1.02-1.42); P = 0.026] were associated with an increased risk for new-onset AF, while the other variables were not. A sensitivity analysis only including patients with isolated coronary artery bypass grafting supported the primary analyses. CPB management following current guideline recommendations appears to have minor or no influence on the risk of developing new-onset AF after cardiac surgery.

BODY TEMPERATURE VARIATION AFTER PACKED CELL TRANSFUSION IN ADULT PATIENTS WITH SEPSIS-WHERE WILL THE PENDULUM STOP?

Background : Critically ill patients with sepsis often require packed cell transfusions (PCTs). Packed cell transfusion causes changes in body's core temperature. Objective : To trace the course and amplitude of body core temperature after PCT in adults with sepsis. Methods : We conducted a population-based retrospective cohort study of patients with sepsis who received one unit of PCT during their hospitalization in a general intensive care unit during 2000-2019. A control group was established by matching each of these patients to a patient who did not receive PCT. We calculated the mean values of urinary bladder temperature for the 24 h before and 24 h after PCT. To evaluate the effect of PCT on body core temperature, multivariable analyses using a mixed linear regression model were performed. Results : The study comprised 1,100 patients who received one unit of PCT and 1,100 matched patients. The mean temperature before PCT was 37.3°C. Immediately from initiation of PCT, body temperature decreased, to a minimum of 37.0°C. During the 24 subsequent hours, the temperature increased gradually and consistently, until a peak temperature of 37.4°C. In a linear regression model, body core temperature increased by a mean 0.06°C in the first 24 h after PCT and decreased by a mean 0.65°C for every 1.0°C increase before PCT. Conclusions : Among critically ill patients with sepsis, PCT itself causes only mild and clinically insignificant temperature changes. Thus, significant changes in core temperature during the 24 h after PCT may indicate an unusual clinical event that requires clinicians' immediate attention.

Relationship between perioperative cardiopulmonary bypass time, platelet count, fibrinogen level, rotational thromboelastometry data, antithrombin level, and blood loss volume and the effects of deep hypothermic circulatory arrest: An observational study.

We hypothesized that perioperative fibrinogen level, platelet count, and rotational thromboelastometry (ROTEM) data values decrease in proportion to cardiopulmonary bypass (CPB) time, particularly in patients who underwent deep hypothermic circulatory arrest (DHCA). A total of 160 patients were enrolled and divided into the following three groups depending on CPB time: <2-h, 2- 3-h, and >3-h groups. Blood samples were obtained during CPB weaning. Platelet count, ROTEM data, fibrinogen level, and antithrombin level were determined. For propensity matching, we selected 15 patients who underwent DHCA and 15 patients who did not undergo DHCA and used propensity scores to match CPB time and other characteristics. The <2-h, 2-3-h, and >3-h groups included 74, 63, and 23 patients, respectively. No significant differences in platelet count and fibrinogen level were observed between the groups. Antithrombin level and amplitude of clot firmness at 10min in the EXTEM and FIBTEM tests were lowest in the >3-h group. Similarly, blood loss volume and transfusion volume were highest in the >3-h group. Significant differences in platelet count, ROTEM data, lowest esophageal and bladder temperatures, and transfusion volume were observed between patients who underwent DHCA and patients who did not undergo DHCA. The longer the CPB time, the greater the perioperative blood loss volume and transfusion volume, particularly if CPB time is greater than 3hours. Sub-group analysis revealed that DHCA affects perioperative platelet count and function as well as blood loss volume.

Challenging Paradigm Limits of Retrograde Cerebral Perfusion During Lower Body Circulatory Arrest

IntroductionRetrograde cerebral perfusion (RCP) is a safe and effective technique to augment cerebral protection during lower body circulatory arrest in patients undergoing elective hemiarch replacement. However, recommendations guiding optimal temperature, flow rate, and perfusion pressure are outdated and potentially overly limiting. We report our experience using RCP for elective hemiarch replacement with parameters that challenge the currently accepted paradigm. MethodsThis was a single-center, retrospective analysis of 319 adult patients who underwent elective hemiarch replacement between February 2010 and 2021 using hypothermic lower body circulatory arrest with RCP alone, RCP followed by antegrade cerebral perfusion (ACP), or ACP alone. Flow rates were adjusted to maintain cerebral perfusion pressure between 30 and 50 mm Hg for RCP and between 40 and 60 mm Hg for ACP. ResultsRCP was used in 22.6% (n = 72) of cases, whereas ACP alone was performed in 77.4% (n = 247) of cases. Baseline patient characteristics were similar between groups. Patients undergoing RCP demonstrated shorter cross-clamp time (97.0 min versus 100.0 min, P = 0.034) and shorter lower body circulatory arrest time (7.0 min versus 10.0 min, P < 0.0001) compared with ACP alone. Nadir bladder temperature was equivalent between groups (27.3°C versus 27.5°C, P = 0.752). There were no significant differences in postoperative complications, neurologic outcomes, or mortality. ConclusionsModerate hypothermic lower body circulatory arrest combined with RCP at target perfusion pressures of 30-50 mm Hg in patients undergoing elective hemiarch replacement results in equivalent neurologic outcomes and overall morbidity to cases using ACP alone. These results challenge the currently accepted paradigm for RCP, which typically uses deep hypothermia while keeping perfusion pressures below 25 mm Hg.

Visceral protection in total arch replacement for aortic dissection: Effect of lower body hypothermia.

Optimal hypothermia strategy for total arch replacement in acute type A aortic dissection (ATAAD) is unclear. A higher temperature during circulatory arrest might reduce tolerance to ischemia for visceral organs. We sought to investigate the effect of hypothermia on visceral protection. From January 2010 to December 2019, 1138 consecutive patients underwent total arch replacement combined with frozen elephant trunk for acute type A aortic dissection. The data were retrospectively collected and analyzed. Visceral organ injury and visceral-related adverse outcomes were defined as acute renal failure or spinal cord injury or both. Multivariate logistic regression analysis and multivariate linear regression model were used. The mean age of patient was 46.9 ± 10.0 years, with a male preponderance (79.6%). Operative mortality was 6.1% (69 patients). Spinal cord injury occurred in 55 (4.8%) patients and 133 (11.7%) patients had acute renal failure. In the multivariate logistic regression model, neither bladder temperature (odds ratio [OR] 0.971, 95% confidence interval [CI] 0.922-1.024, p = .278) nor circulatory arrest duration (OR 1.017, 95% CI 0.987-1.047, p = .267) significantly associated with visceral-related adverse outcomes. Female, lower limb malperfusion, age, cardiopulmonary bypass(CPB) duration and preoperative serum creatinine level were independent risk factors of visceral-related outcomes. There was a significant negative correlation between bladder temperature and CPB duration in multiple linear regression model (β = -3.67, p < .0001). Bladder temperature had no effect on outcomes related to visceral protection under the premise of short circulatory arrest duration, but female gender, lower limb malperfusion, age, CPB duration, and preoperative serum creatinine level were independent risk factors. Bladder temperature negatively correlated to CPB duration.

Evaluation of a Wearable in-Ear Sensor for Temperature and Heart Rate Monitoring: A Pilot Study

In the context of the COVID-19 pandemic, wearable sensors are important for early detection of critical illness especially in COVID-19 outpatients. We sought to determine in this pilot study whether a wearable in-ear sensor for continuous body temperature and heart rate monitoring (Cosinuss company, Munich) is sufficiently accurate for body temperature and heart rate monitoring. Comparing with several anesthesiologic standard of care monitoring devices (urinary bladder and zero-heat flux thermometer and ECG), we evaluated the in-ear sensor during non-cardiac surgery (German Clinical Trials Register Reg.-No: DRKS00012848). Limits of Agreement (LoA) based on Bland–Altman analysis were used to study the agreement between the in-ear sensor and the reference methods. The estimated LoA of the Cosinuss One and bladder temperature monitoring were [-0.79, 0.49] °C (95% confidence intervals [-1.03, -0.65] (lower LoA) and [0.35, 0.73] (upper LoA)), and [-0.78, 0.34] °C (95% confidence intervals [-1.18, -0.59] (lower LoA) and [0.16, 0.74] (upper LoA)) of the Cosinuss One and zero-heat flux temperature monitoring. 89% and 79% of Cosinuss One temperature monitoring were within ± 0.5 °C limit of bladder and zero-heat flux monitoring, respectively. The estimated LoA of Cosinuss One and ECG heart rate monitoring were [-4.81, 4.27] BPM (95% confidence intervals [-5.09, -4.56] (lower LoA) and [4.01, 4.54] (upper LoA)). The proportion of detection differences within ± 2BPM was 84%. Body temperature and heart rate were reliably measured by the wearable in-ear sensor.

Temperature measurements of a wearable and wireless axillary sensor iThermonitor but not a bladder probe represents the core temperature during laparoscopic rectal surgery.

To investigate whether the temperature recorded by an iThermonitor has better concordance with the core temperature than the bladder temperature recorded by a Foley catheter sensor in laparoscopic rectal surgery. Eighty-two adults undergoing laparoscopic rectal surgery were enrolled. Temperatures were continuously measured by a distal oesophageal probe (the reference core temperature), axillary iThermonitor and Foley catheter sensor (bladder temperature) in each patient during surgery. Pairs of axillary and core temperatures or pairs of bladder temperature and core temperatures were compared and summarized using linear regression and the repeated-measured Bland-Altman method during the whole surgical period and pneumoperitoneum period. There were 3303 pairs of temperature measurements during the whole surgical period. The mean difference between iThermonitor and oesophageal was 0.05°C ; the limits of agreement were - 0.48 to 0.56°C. The mean difference between the oesophagus and bladder was 0.28°C; the limits of agreement were - 0.39 to 0.94°C (P < 0.001, F-test vs. iThermonitor). Ninety -five% of all iThermonitor values were within 0.5°C of oesophageal temperature, whereas the proportion for oesophageal and bladder differences within 0.5°C was only 84% (95% confidence interval 80-88%). Lin's CCC for the iThermonitor and bladder measurements were 0.842 (95%CI: 0.831-0.851) and 0.688 (95%CI: 0.673-0.703) respectively. Similar results were found during the pneumoperitoneum period. The temperature recorded by iThermonitor has better concordance with the core temperature than the bladder temperature recorded by Foley catheter sensor in laparoscopic rectal surgery.

A scalable hyperthermic intravesical chemotherapy (HIVEC) setup for rat models of bladder cancer

Hyperthermic intravesical chemotherapy (HIVEC)—whereby the bladder is heated to ± 43 °C during a chemotherapy instillation—can improve outcomes of non-muscle invasive bladder cancer (NMIBC) treatments. Experiments in animal models are required to explore new hyperthermia based treatments. Existing HIVEC devices are not suitable for rodents or large-scale animal trials. We present a HIVEC setup compatible with orthotopic rat models. An externally heated chemotherapeutic solution is circulated in the bladder through a double-lumen catheter with flow rates controlled using a peristaltic pump. Temperature sensors in the inflow channel, bladder and outflow channel allow temperature monitoring and adjustments in real-time. At a constant flow rate of 2.5 mL/min the system rapidly reaches the desired bladder temperature of 42–43 °C with minimal variability throughout a one-hour treatment in a rat bladder phantom, as well as in euthanised and live rats. Mean intraluminal bladder temperatures were 42.92 °C (SD = 0.15 °C), 42.45 °C (SD = 0.37 °C) and 42.52 °C (SD = 0.09 °C) in the bladder phantom, euthanised, and live rats respectively. Thermal camera measurements showed homogenous heat distributions over the bladder wall. The setup provides well-controlled thermal dose and the upscaling needed for performing large scale HIVEC experiments in rats.

Direct Innominate Artery Cannulation versus Side Graft for Selective Antegrade Cerebral Perfusion during Aortic Hemiarch Replacement.

Background Selective antegrade cerebral perfusion (SACP) has become our preferred method for cerebral protection during open arch cases. While the initial approach involved sewing a graft to the innominate artery as the arterial cannulation site, our access strategy has since evolved to central aortic cannulation with use of a percutaneous cannula in the innominate for SACP. We hypothesized that SACP delivered via direct innominate cannulation using a 12- or 14-Fr cannula results in equivalent outcomes to cases utilizing a side graft. Methods This was a single-center, retrospective analysis of 211 adult patients who underwent elective hemiarch replacement using hypothermic circulatory arrest with SACP via the innominate artery between 2012 and 2020. Urgent and emergent cases were excluded. Results A side graft sutured to the innominate was utilized in 81% ( n = 171) of patients, while direct innominate artery cannulation was performed in 19% ( n = 40) of patients. Baseline patient characteristics were similar between groups aside from a higher baseline creatinine in the direct cannulation group (1.3 vs. 0.9, p = 0.032). Patients undergoing direct cannulation demonstrated shorter cardiopulmonary bypass time (132.7 vs. 154.9 minutes, p = 0.020) and shorter circulatory arrest time (8.1 vs. 10.9 minutes, p = 0.004). Nadir bladder temperature did not significantly differ between groups (27.2°C for side graft vs. 27.6°C for direct cannulation, p = 0.088). There were no significant differences in postoperative outcomes. Conclusion Direct cannulation of the innominate artery with a 12- or 14-Fr cannula for SACP during hemiarch replacement is a safe alternative to using a sutured side graft. While cardiopulmonary bypass and circulatory arrest times appear improved, this is likely attributable to accumulation of experience and proficiency in technique. However, direct innominate artery cannulation may facilitate quicker completion of these procedures by eliminating the time necessary to suture a graft to the innominate artery.

超高齢の偶発性低体温症に対しVA–ECMOにより復温し救命し得た1例(Life–saving VA–ECMO rewarming in the oldest old with accidental hypothermia: a case report)

要旨 偶発性低体温症（accidental hypothermia: AH）により難治性心室細動を来した超高齢者に対し，補助人工心肺であるVA–ECMO（veno–arterial extracorporeal membrane oxygenation）を用いて救命し得た。症例はADL（activities of daily living）良好な90歳の女性。某年3月，浴槽内で意識障害の状態を発見され救急要請となった。当院搬送時，血圧41/26mmHg, 心拍数 37/分，呼吸数 6/分，膀胱温 24℃と高度低体温症で，ブランケットによる復温を開始した。心室細動を来し電気ショックで洞調律に復調したが，その後も心室細動となり難治性心室細動と判断した。超高齢だがADLを考慮し，家族に説明してVA–ECMOにより復温，および体外循環の確立を図る方針とした。導入後，復温したのち心室細動は収束した。翌日にVA–ECMOを離脱，第3病日に人工呼吸器を離脱した。その後，全身状態良好で転院した。体外循環式心肺蘇生法は難治性かつ可逆性の心停止に有効で，AHでVA–ECMOによる復温が奏功した報告は多い。一方，AHは高齢者に多く，超高齢者に侵襲的な中枢加温の導入は一般的に難しい。しかし，超高齢でも蘇生条件とADL次第で，難治性心室細動を伴うAHの循環不全に対して体外循環式心肺蘇生法を検討する必要がある。