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Aims: The end-tidal carbon dioxide (ETCO2) is frequently measured in cardiac arrest (CA) patients, for management and for predicting survival. Our goal was to study the PaCO2 and ETCO2 in hypothermic cardiac arrest patients.Methods: We included patients with refractory CA assessed for extracorporeal cardiopulmonary resuscitation. Hypothermic patients were identified from previously prospectively collected data from Poland, France and Switzerland. The non-hypothermic CA patients were identified from two French cohort studies. The primary parameters of interest were ETCO2 and PaCO2 at hospital admission. We analysed the data according to both alpha-stat and pH-stat strategies.Results: We included 131 CA patients (39 hypothermic and 92 non-hypothermic). Both ETCO2 (p < 0.001) and pH-stat PaCO2 (p < 0.001) were significantly lower in hypothermic compared to non-hypothermic patients, which was not the case for alpha-stat PaCO2 (p = 0.15). The median PaCO2-ETCO2 gradient was greater for hypothermic compared to non-hypothermic patients when using the alpha-stat method (46 mmHg vs 30 mmHg, p = 0.007), but not when using the pH-stat method (p = 0.10). Temperature was positively correlated with ETCO2 (p < 0.01) and pH-stat PaCO2 (p < 0.01) but not with alpha-stat PaCO2 (p = 0.5). The ETCO2 decreased by 0.5 mmHg and the pH-stat PaCO2 by 1.1 mmHg for every decrease of 1° C of the temperature. The proportion of survivors with an ETCO2 ≤ 10 mmHg at hospital admission was 45% (9/25) for hypothermic and 12% (2/17) for non-hypothermic CA patients.Conclusions: Hypothermic CA is associated with a decrease of the ETCO2 and pH-stat PaCO2 compared with non-hypothermic CA. ETCO2 should not be used in hypothermic CA for predicting outcome. [ABSTRACT FROM AUTHOR]

Wstęp W połowie XX wieku hipotermię uznano za samodzielną jednostkę chorobową i rozpoznawano ją u każdego pacjenta, u którego temperatura centralna była niższa niż 35°C. Europejska Rada Resuscytacji (ERC) uwzględnia również rozpoznanie hipotermii w przypadku braku możliwości zbadania temperatury centralnej, gdy w wywiadzie potwierdzono ekspozycję na zimno, a tułów chorego jest zimny w dotyku. Nie przyjęto jednolitej klasyfikacji hipotermii, istnieje kilka podziałów. Według Amerykańskiego Towarzystwa Kardiologicznego (ang. American Heart Association - AHA) jeśli temperatura ciała obniży się do 34°C można rozpoznać hipotermię łagodną, przy temperaturze 34-30°C - umiarkowaną, a poniżej 30°C - hipotermię ciężką. ERC przyjmuje, że hipotermia łagodna mieści się w zakresie temperatur 35-32°C, hipotermia umiarkowana 32-28°C, a hipotermia ciężka poniżej 28°C. Po rozpoznaniu hipotermii priorytetem w postępowaniu ratowniczym jest zastosowanie efektywnego sposobu ogrzewania. Według aktualnych wytycznych ERC w ciężkiej hipotermii zaleca się leczenie za pomocą ciągłego pozaustroj owego natleniania - ECMO (ang. extracorporeal membranę oxygenation). Materiał i metody Badanie przeprowadzono od styczna 2016 roku do lutego 2019 roku w Klinice Anestezjologii i Intensywnej Terapii i Klinice Kardiochirurgii Wojewódzkiego Szpitala Zespolonego w Kielcach. W pracy przedstawiono historię choroby dziesięciu pacjentów z rozpoznaniem ciężkiej hipotermii, leczonych z użyciem ECMO. Wyniki Efekty leczenia przy zastosowaniu technik ogrzewania (ECMO) pacjentów w najgłębszych stadiach hipotermii okazały się bardzo skuteczne w przypadku 4 chorych. Osoby te po kilkunastu dniach hospitalizacji były wypisywane ze szpitala w dobrym stanie ogólnym. Zastosowanie ECMO w konfiguracji tętniczo-żylnej jako tzw. złotego środka w leczeniu hipotermii nie jest jednak pozbawione powikłań. Wnioski 1. Hipotermia może rozwinąć się u człowieka o każdej porze roku. Okolicznościami najczęściej prowadzącymi do znacznego wychłodzenia organizmu są: zimne powietrze, warunki atmosferyczne pogłębiające odczucie zimna (duża wilgotność powietrza, wiatr) oraz znaczna utrata ciepła. 2. Wczesne rozpoznanie, identyfikacja czynników ryzyka i zgodna ze standardami kwalifikacja pacjentów do ogrzewania przy pomocy ECMO umożliwiają skuteczne leczenie. 3. Osiągnięcie normotermii nie gwarantuje przeżycia chorego. 4. Zaburzenia krzepnięcia krwi oraz masywne krwawienia uniemożliwiają skuteczne leczenie za pomocą ciągłego pozaustrojowego natleniania. [ABSTRACT FROM AUTHOR]

Highlights from the article: We therefore included patients who sustained a "witnessed cardiac arrest that was thought to be due to hypothermia". Second, as underlined by Strapazzon et al. a substantial proportion of patients in our study had asystole as the initial cardiac rhythm. 5 M. Pasquier, O. Hugli, P. Paal, Hypothermia outcome prediction after extracorporeal life support for hypothermic cardiac arrest patients: the HOPE score, Resuscitation, 126, 2018, 58-64.

Aim of the Study: Predictive factors for poor outcomes in hypothermic cardiac arrest (HCA) differ from those in normothermic out-of-hospital cardiac arrest (OHCA). This study aimed to evaluate the outcomes of extracorporeal life support (ECLS) in HCA patients who may not be considered eligible based on the guidelines set by the Extracorporeal Life Support Organization (ELSO)., Methods: A retrospective multicentre study included 127 HCA patients, divided into two groups: those meeting the ELSO eligibility criteria for ECLS, and those with at least one of the following ELSO exclusion criteria: age over 70 years, unwitnessed cardiac arrest, or asystole., Results: Among the 62 patients who met the ELSO criteria, 38 (61 %) survived to hospital discharge, with 34 (89 %) achieving a favourable neurological outcomes. Of the 65 patients who received ECLS despite not meeting ELSO criteria, 24 (37 %) survived to discharge, with 20 (83 %) demonstrating a favourable neurological outcomes. In patients not meeting one or two ELSO criteria, survival rates were 18 of 47 (38 %) and 6 of 16 (38 %) respectively, with 83 % of survivors in both groups achieving favourable neurological outcomes. The two patients who failed to meet all three ELSO criteria did not survive., Conclusion: Qualification of patients with hypothermic cardiac arrest for ECLS rewarming should not be strictly based on guidelines for normothermic cardiac arrest, as this may result in not initiating potentially life-saving treatment for patients who could have favourable prognoses for survival with good neurological outcomes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: The use of thermal insulations reduces the risk of hypothermia, therefore decreases the risk of death in trauma victims. The aim of the study was to assess whether thermal insulations cause artifacts, which may hinder the diagnosis of injuries, and how the used thermo-systems alter the radiation dose in polytrauma computed tomography., Methods: Computed tomography scans were made using the road accident victim body wrapped consecutively with 7 different covers. 14 injury areas were listed and evaluated by 22 radiologists. The radiation dose was measured using a dosimeter placed on the victim in the abdominal area., Results: No significant artifacts in any of the tested covers were observed. The presence of few minor artifacts did not hinder the assessment of injuries. Certain materials increased (up to 19,1%) and some decreased (up to -30,3%) the absorbed radiation dose., Conclusions: Thermal insulation systems tested in this study do not cause significant artifacts hindering assessment of injuries in CT scans. Concern for artifacts and increased radiation dose should not be a reason to remove patients' thermal insulation during performing trauma CT-scanning., Competing Interests: Declarations. Competing interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024. The Author(s).)

Objective: To indicate factors predicting return of spontaneous circulation in patients with hypothermic cardiac arrest in the pre-rewarming period., Methods: A multicenter retrospective study was conducted. We included patients who had suffered cardiac arrest caused by severe accidental hypothermia with a core body temperature of ≤ 28 °C. Patients who had achieved return of spontaneous circulation before commencement of active rewarming at the hospital were compared to those who remained in cardiac arrest., Results: A total of 156 patients suffering hypothermic cardiac arrest were included in the study. In 14 of them (9%) resuscitation was successful before rewarming. Factors associated with return of spontaneous circulation were as follows: witnessed onset of cardiac arrest (p = 0.04); a higher core body temperature (p = 0.005) with a prognostic threshold of 24.6 °C; and a higher arterial oxygen partial pressure (p = 0.04) with a prognostic threshold of 81 mmHg. One patient after successful resuscitation sustained recurrence of cardiac arrest during rewarming., Conclusions: Patients with core body temperature < 25 °C, hypoxemia, and those who sustained unwitnessed hypothermic cardiac arrest have weak chances for successful resuscitation before rewarming. They can benefit from immediate transportation to an extracorporeal life support facility under continuous cardiopulmonary resuscitation. Effective rewarming and oxygenation during the prehospital period can increase the chances for return of spontaneous circulation. Recurrence of cardiac arrest during rewarming is uncommon., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Hemodynamically unstable patients with severe hypothermia and preserved circulation should be transported to dedicated extracorporeal life support (ECLS) centers, but not all are eligible for extracorporeal therapy. In this group of patients, the outcome of rewarming may sometimes be unfavorable. It is, therefore, crucial to identify potential risk factors for death. Furthermore, it is unclear what criterion for hemodynamic stability should be adopted for patients with severe hypothermia. The aim of this study is to identify pre-rewarming predictors of death and their threshold values in hypothermic patients with core temperature ≤ 28 °C and preserved circulation, who were treated without extracorporeal rewarming. We conducted a multicenter retrospective study involving patients in accidental hypothermia with core temperature 28 °C or lower, and preserved spontaneous circulation on rewarming initiation. The data were collected from the International Hypothermia Registry, HELP Registry, and additional hospital data. The primary outcome was survival to hospital discharge. We conducted a multivariable logistic regression and receiver operating characteristic curve (ROC) analysis. In the multivariate analysis of laboratory tests and vital signs, systolic blood pressure (SBP) adjusted for cooling circumstances and base excess (BE) were identified as the best predictor of death (OR 0.974 95% CI 0.952-0.996), AUC ROC 0.79 (0.70-0.88). The clinically relevant cutoff for SBP was identified at 90 mmHg with a sensitivity of 0.74 (0.54-0.89) and a specificity of 0.70 (0.60-0.79). The increased risk of death among hypothermic patients with preserved circulation occurs among those with an SBP below 90 mmHg and in those who developed hypothermia in their homes., (© 2024. The Author(s).)

Background: Due to the distinctive nature of cardiac surgery, patients suffering from hereditary spherocytosis (HS) are potentially at a high risk of perioperative complications resulting from hemolysis. Despite being the most prevalent cause of hereditary chronic hemolysis, the standards of surgical management are based solely on expert opinion., Objective: We analyze the risk of hemolysis in HS patients after cardiac surgery based on a systematic review of the literature. We also describe a case of a patient with hereditary spherocytosis who underwent aortic valve repair., Methods: This systematic review was registered in the PROSPERO international prospective register of systematic reviews (CRD42023417666) and included records from Embase, MEDLINE, Web of Science, and Google Scholar databases. The case study investigates a 38-year-old patient who underwent surgery for an aortic valve defect in mid-2022., Results: Of the 787 search results, 21 studies describing 23 cases of HS undergoing cardiac surgery were included in the final analysis. Hemolysis was diagnosed in five patients (one coronary artery bypass graft surgery, two aortic valve bioprosthesis, one ventricular septal defect closure, and one mitral valve plasty). None of the patients died in the perioperative period. Also, no significant clinical hemolysis was observed in our patient during the perioperative period., Conclusions: The literature data show that hemolysis is not common in patients with HS undergoing various cardiac surgery techniques. The typical management of a patient with mild/moderate HS does not appear to increase the risk of significant clinical hemolysis. Commonly accepted beliefs about factors inducing hemolysis during cardiac surgery may not be fully justified and require further investigation., (© 2024. The Author(s).)

Study Objective: To indicate predictors of witnessed hypothermic cardiac arrest., Methods: We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome., Results: Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO 2 , and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO 2 of 72 mmHg, and uncorrected PaO 2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction., Conclusions: In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities., Competing Interests: Declaration of competing interest None declared by the authors., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest.

Lung ultrasound is gaining popularity as a quick, easy, and accurate method for the detection of pneumothorax. The typical sonographic features of pneumothorax are the absence of lung sliding, the presence of a lung point, the absence of a lung pulse, and the absence of B-lines. However, we found that in some cases, each of these elements might be misleading.

Accidental hypothermia, defined as an unintentional drop of the body core temperature below 35 °C, is one of the causes of cardiocirculatory instability and reversible cardiac arrest. Currently, extracorporeal life support (ECLS) rewarming is recommended as a first-line treatment for hypothermic cardiac arrest patients. The aim of the ECLS rewarming is not only rapid normalization of core temperature but also maintenance of adequate organ perfusion. Veno-arterial extracorporeal membrane oxygenation (ECMO) is a preferred technique due to its lower anticoagulation requirements and potential to prolong circulatory support. Although highly efficient, ECMO is acknowledged as an invasive treatment option, requiring experienced medical personnel and is associated with the risk of serious complications. In this review, we aimed to discuss the clinical aspects of ECMO management in severely hypothermic cardiac arrest patients.

Treatment recommendations for rewarming patients in severe accidental hypothermia with preserved spontaneous circulation have a weak evidence due to the absence of randomized clinical trials. We aimed to compare the outcomes of extracorporeal versus less-invasive rewarming of severely hypothermic patients with preserved spontaneous circulation. We conducted a multicenter retrospective study. The patient population was compiled based on data from the HELP Registry, the International Hypothermia Registry, and a literature review. Adult patients with a core temperature <28°C and preserved spontaneous circulation were included. Patients who underwent extracorporeal rewarming were compared with patients rewarmed with less-invasive methods, using a matched-pair analysis. The study population consisted of 50 patients rewarmed extracorporeally and 85 patients rewarmed with other, less-invasive methods. Variables significantly associated with survival included: lower age; outdoor cooling circumstances; higher blood pressure; higher PaCO 2 ; higher BE; higher HCO 3 ; and the absence of comorbidities. The survival rate was higher in patients rewarmed extracorporeally ( p = 0.049). The relative risk of death was twice as high in patients rewarmed less invasively. Based on our data, we conclude that patients in severe accidental hypothermia with circulatory instability can benefit from extracorporeal rewarming without an increased risk of complications., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

Background: Despite its potential advantages, ultrasound-guided cannulation of the axillary vein in the infraclavicular area is still rarely used as an alternative to other techniques. There are few large series demonstrating the safety and feasibility of this approach., Methods: Retrospective analysis of data on patients undergoing ultrasound-guided, long-axis, in-plane infraclavicular axillary vein cannulation for the incidence of complications and the failure rate from two secondary-care hospitals., Results: The analysis included 710 successful attempts of axillary vein long-axis, in-plane, US-guided cannulation, and 24 (3.3%) failed attempts. We recorded a 96.7% success rate with an overall incidence of complications of 13%, mainly malposition (8.1%). There was one case of pneumothorax (0.14%), five cases of arterial puncture (0.7%), and two cases of brachial plexus injury., Conclusions: The US-guided axillary central venous cannulation (CVC) access technique can be undertaken successfully in patients, even in challenging circumstances. Taken together with existing work on the utility and safety of this technique, we suggest that it should be adopted more widely in clinical practice., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Out-of-hospital cardiac arrest (OHCA) remains a leading cause of global mortality, while survivors are burdened with long-term neurological and cardiovascular complications. OHCA management at the hospital level remains challenging, due to heterogeneity of OHCA presentation, the critical status of OHCA patients reaching the return of spontaneous circulation (ROSC), and the demands of post ROSC treatment. The validity and optimal timing for coronary angiography is one important, yet not fully defined, component of OHCA management. Guidelines state clear recommendations for coronary angiography in OHCA patients with shockable rhythms, cardiogenic shock, or in patients with ST-segment elevation observed in electrocardiography after ROSC. However, there is no established consensus on the angiographic management in other clinical settings. While coronary angiography may accelerate the diagnostic and therapeutic process (provided OHCA was a consequence of coronary artery disease), it might come at the cost of impaired post-resuscitation care quality due to postponing of intensive care management. The aim of the current statement paper is to discuss clinical strategies for the management of OHCA including the stratification to invasive procedures and the rationale behind the risk-benefit ratio of coronary angiography, especially with patients in critical condition.

In 1755 in Bergemoletto, Italy, an avalanche buried 4 people (2 women, a girl, and a boy) and several animals in a stable. After 37 d in a pitch-dark confined space, 3 of the 4 people were rescued alive. The 3 survivors had only goat milk, a few chestnuts, a few kg of raw kid meat, and meltwater for nutrition. We describe the longest-known survival in an avalanche burial and discuss the medical and psychological problems of the survivors. The boy died. When they were extricated, all 3 survivors were exhausted, cachectic, and unable to stand or walk. They were severely malnourished and were experiencing tingling, tremors, and weakness in the legs; constipation; changes in taste; and amenorrhea. One of the women had persistent eye problems and developed symptoms consistent with post-traumatic stress disorder. The survivors were given slow refeeding. It took from 1 to 6 wk before they could walk. We compare this case to other long-duration burials, especially mining accidents, and describe the rescue and patient care after long-duration burials. This case demonstrates that people can overcome extremely adverse conditions and survive., (Copyright © 2022 Wilderness Medical Society. All rights reserved.)

Background: The purpose of this study was to compare the safety and clinical outcomes of transcarotid (TC) and transapical access (TA) transcatheter aortic valve implantation (TAVI) patients whom the transfemoral approach (TF) was not feasible., Methods: The analysis included consecutive patients with severe symptomatic aortic stenosis treated from 2017 to 2020 with TC-TAVI or TA-TAVI in two high-volume TAVI centers. The approach was selected by multidisciplinary heart teams after analyzing multislice computed tomography of the heart, aorta and peripheral arteries, transthoracic echocardiography and coronary angiography., Results: One hundred and two patients were treated with alternative TAVI accesses (TC; n = 49 and TA; n = 53) in our centers. The groups were similar regarding age, gender, New York Heart Association class, and echocardiography parameters. Patients treated with TC-TAVI had significantly higher surgical risk. The procedural success rate was similar in both groups (TC-TAVI 98%; TA-TAVI 98.1%; p = 0.95). The rate of Valve Academic Research Consortium-2 defined clinical events was low in both groups. The percentage of new-onset rhythm disturbances and permanent pacemaker implantation was similar in TC and TA TAVI (4.1% vs. 11.3%; p = 0.17 and 10.2% vs. 5.7%; p = 0.39, respectively). In the TA-TAVI group, significantly more cases of pneumonia and blood transfusions were observed (11% vs. 0%; p = 0.01 and 30.2% vs. 12.2%; p = 0.03). The 30-day mortality was similar in TC and TA groups (4.1% vs. 5.7%; p = 0.71, respectively)., Conclusions: Both TC and TA TAVI are safe procedures in appropriately selected patients and are associated with a low risk of complications.

Zafren, Ken, Raimund Lechner, Peter Paal, Hermann Brugger, Giles Peek, and Tomasz Darocha. Induced hypothermia as cold as 3°C in humans: Forgotten cases rediscovered. High Alt Med Biol . 23:105-113.-The lowest temperature from which humans can be successfully rewarmed from accidental hypothermia is unknown. The lowest published core temperature with survival from accidental hypothermia is 11.8°C. We recently reported a rediscovered case series of patients in whom profound hypothermia was induced for surgery. The patient in this case series with the lowest core temperature, 4.2°C, survived neurologically intact. We subsequently rediscovered several additional case series of induced hypothermia to core temperatures below 11.8°C. In one case series, at least one patient was cooled to 3°C. We do not know if any patient survived cooling to 3°C. As in the previous case series, the authors of the additional reports presented physiological data at various core temperatures, showing wide variations in individual responses to hypothermia. These data add to our understanding of the physiology of profound hypothermia. Although induced hypothermia for surgery differs from accidental hypothermia, survival from very low temperatures in induced hypothermia provides evidence that humans with accidental hypothermia can be resuscitated successfully from temperatures much lower than 11.8°C. We continue to advise against using core temperature alone to decide if a hypothermic patient in cardiac arrest has a chance of survival.

Mallampati score has been identified and accepted worldwide as an independent predictor of difficult intubation and obstructive sleep apnea. We aimed to determine whether Mallampati score assessed on the first patient medical assessment allowed us to stratify the risk of worsening of conditions in patients hospitalized due to COVID-19. A total of 493 consecutive patients admitted between 13 November 2021 and 2 January 2022 to the temporary hospital in Pyrzowice were included in the analysis. The clinical data, chest CT scan, and major, clinically relevant laboratory parameters were assessed by patient-treating physicians, whereas the Mallampati score was assessed on admission by investigators blinded to further treatment. The primary endpoints were necessity of active oxygen therapy (AOT) during hospitalization and 60-day all-cause mortality. Of 493 patients included in the analysis, 69 (14.0%) were in Mallampati I, 57 (11.6%) were in Mallampati II, 78 (15.8%) were in Mallampati III, and 288 (58.9%) were in Mallampati IV. There were no differences in the baseline characteristics between the groups, except the prevalence of chronic kidney disease (p = 0.046). Patients with Mallampati IV were at the highest risk of AOT during the hospitalization (33.0%) and the highest risk of death due to any cause at 60 days (35.0%), which significantly differed from other scores (p = 0.005 and p = 0.03, respectively). Mallampati IV was identified as an independent predictor of need for AOT (OR 3.089, 95% confidence interval 1.65−5.77, p < 0.001) but not of all-cause mortality at 60 days. In conclusion, Mallampati IV was identified as an independent predictor of AOT during hospitalization. Mallampati score can serve as a prehospital tool allowing to identify patients at higher need for AOT.

Ultrathin reflective foils (URFs) are widely used to protect patients from heat loss, but there is no clear evidence that they are effective. We review the physics of thermal insulation by URFs and discuss their clinical applications. A conventional view is that the high reflectivity of the metallic side of the URF is responsible for thermal protection. In most circumstances, the heat radiated from a well-clothed body is minimal and the reflecting properties of a URF are relatively insignificant. The reflection of radiant heat can be impaired by condensation and freezing of the moisture on the inner surface and by a tight fit of the URF against the outermost layer of insulation. The protection by thermal insulating materials depends mostly on the ability to trap air and increases with the number of covering layers. A URF as a single layer may be useful in low wind conditions and moderate ambient temperature, but in cold and windy conditions a URF probably best serves as a waterproof outer covering. When a URF is used to protect against hypothermia in a wilderness emergency, it does not matter whether the gold or silver side is facing outward., (Copyright © 2021 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.)

Severely hypothermic patients, especially suffering cardiac arrest, require highly specialized treatment. The most common problems affecting the recognition and treatment seem to be awareness, logistics, and proper planning. In severe hypothermia, pathophysiologic changes occur in the cardiovascular system leading to dysrhythmias, decreased cardiac output, decreased central nervous system electrical activity, cold diuresis, and noncardiogenic pulmonary edema. Cardiac arrest, multiple organ dysfunction, and refractory vasoplegia are indicative of profound hypothermia. The aim of these narrative reviews is to describe the peculiar pathophysiology of patients suffering cardiac arrest from accidental hypothermia. We describe the good chances of neurologic recovery in certain circumstances, even in patients presenting with unwitnessed cardiac arrest, asystole, and the absence of bystander cardiopulmonary resuscitation. Guidance on patient selection, prognostication, and treatment, including extracorporeal life support, is given., Competing Interests: The authors have no funding and conflicts of interest to report., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the ASAIO.)

Accidental hypothermia is an unintentional drop of core temperature below 35 °C. Annually, thousands die of primary hypothermia and an unknown number die of secondary hypothermia worldwide. Hypothermia can be expected in emergency patients in the prehospital phase. Injured and intoxicated patients cool quickly even in subtropical regions. Preventive measures are important to avoid hypothermia or cooling in ill or injured patients. Diagnosis and assessment of the risk of cardiac arrest are based on clinical signs and core temperature measurement when available. Hypothermic patients with risk factors for imminent cardiac arrest (temperature < 30 °C in young and healthy patients and <32 °C in elderly persons, or patients with multiple comorbidities), ventricular dysrhythmias, or systolic blood pressure < 90 mmHg) and hypothermic patients who are already in cardiac arrest, should be transferred directly to an extracorporeal life support (ECLS) centre. If a hypothermic patient arrests, continuous cardiopulmonary resuscitation (CPR) should be performed. In hypothermic patients, the chances of survival and good neurological outcome are higher than for normothermic patients for witnessed, unwitnessed and asystolic cardiac arrest. Mechanical CPR devices should be used for prolonged rescue, if available. In severely hypothermic patients in cardiac arrest, if continuous or mechanical CPR is not possible, intermittent CPR should be used. Rewarming can be accomplished by passive and active techniques. Most often, passive and active external techniques are used. Only in patients with refractory hypothermia or cardiac arrest are internal rewarming techniques required. ECLS rewarming should be performed with extracorporeal membrane oxygenation (ECMO). A post-resuscitation care bundle should complement treatment.

Background: The treatment of aortic root aneurysm remains challenging for both cardiac surgeons and cardiologists., Aims: This study aimed to assess and compare the long-term outcomes of different approaches to aortic root replacement (ARR)., Methods: All elective patients operated for aortic root aneurysm with or without aortic regurgitation at our institution over a 10-year period were included. We excluded patients with any degree of aortic stenosis and with active endocarditis. We assessed mortality, freedom from reoperation, freedom from aortic valve regurgitation, and the rate of hemorrhagic and thromboembolic complications., Results: Two hundred and four patients underwent elective aortic root replacement: 107 (53%) valve-sparing aortic root replacement (VSARR), 35 (17%) mechanical Bentall procedure (MB), and 62 (30%) Bio-Bentall procedure (BB). Early mortality for VSARR, BB, and MB group was 2.8%, 4.8%, and 0%, respectively (P = 0.40). Estimated 5-year survival was: 90.2% vs. 78.4% vs. 94.2%, respectively (P = 0.12), 5-year freedom from reoperation: 97.8%, 96.6%, and 96.8%, respectively (P = 0.99). Estimat-ed 5-year freedom from complications was: 94.2%, 83.1% and 57.3% in the VSARR, BB and MB group, respectively (P <0.001). On last follow-up echocardiography, 90.5%, 98.4%, and 97.1% (P = 0.08) of patients were free from aortic regurgitation grade 2 or higher. The median (IQR) aortic valve peak gradient was 9 (6-12) mm Hg, 12 (10-18) mm Hg and 16 (14-22) mm Hg, respectively (P <0.001). Complications were predicted by mechanical Bentall (hazard ratio, 6.70 [2.54-17.63]; P <0.001)., Conclusion: With the same mortality, freedom from reoperation, and a minimal late complication rate in comparison with mechanical Bentall and Bio-Bentall, VSARR might be the preferred approach to aortic root aneurysm.