On-site treatment of avalanche victims: Scoping review and 2023 recommendations of the international commission for mountain emergency medicine (ICAR MedCom).

INTRODUCTION: The International Commission for Mountain Emergency Medicine (ICAR MedCom) developed updated recommendations for the management of avalanche victims. METHODS: ICAR MedCom created Population Intervention Comparator Outcome (PICO) questions and conducted a scoping review of the literature. We evaluated and graded the evidence using the American College of Chest Physicians system. RESULTS: We included 120 studies including original data in the qualitative synthesis. There were 45 retrospective studies (38%), 44 case reports or case series (37%), and 18 prospective studies on volunteers (15%). The main cause of death from avalanche burial was asphyxia (range of all studies 65-100%). Trauma was the second most common cause of death (5-29%). Hypothermia accounted for few deaths (0-4%). CONCLUSIONS AND RECOMMENDATIONS: For a victim with a burial time ≤ 60 minutes without signs of life, presume asphyxia and provide rescue breaths as soon as possible, regardless of airway patency. For a victim with a burial time > 60 minutes, no signs of life but a patent airway or airway with unknown patency, presume that a primary hypothermic CA has occurred and initiate cardiopulmonary resuscitation (CPR) unless temperature can be measured to rule out hypothermic cardiac arrest. For a victim buried > 60 minutes without signs of life and with an obstructed airway, if core temperature cannot be measured, rescuers can presume asphyxia-induced CA, and should not initiate CPR. If core temperature can be measured, for a victim without signs of life, with a patent airway, and with a core temperature < 30 °C attempt resuscitation, regardless of burial duration.

Clinical characteristics and haemodynamic state of patients undergoing interhospital transfer for postpartum haemorrhage: A study of a single-centre helicopter emergency medical service.

OBJECTIVE: Uterine artery embolization is an attractive option for the management of postpartum haemorrhage, however it is not available in every hospital. We compared the clinical characteristics and haemodynamic state of patients with postpartum haemorrhage, before and after helicopter transfer to a tertiary hospital for possible uterine artery embolization. We also analysed whether the type of treatment could modify the outcome. STUDY DESIGN: Between 1999 and 2019 in Switzerland, we retrospectively found 82 consecutive patients with postpartum haemorrhage who were transferred by a physician-staffed helicopter emergency medical service to the tertiary hospital for potential uterine artery embolization. The collected data included the type of delivery, estimated blood loss, shock index and blood lactate levels before transfer and at destination, uterine artery embolization rate and hospital mortality rate. Our primary outcome was to describe the clinical characteristics, outcomes and haemodynamic state of the patients with postpartum haemorrhage before and after helicopter transfer. Our secondary outcome was to report the treatments performed at the tertiary hospital. The collected data were analysed with Stata version 14 (Stata Corporation, College Station, TX, USA). Continuous data are compared by using the Student's t-test or the Mann-Whitney U test, as appropriate. RESULTS: We included 69 patients. Postpartum haemorrhage occurred after vaginal delivery in 38 cases (55%). Blood loss prior to transfer exceeded 2 L in 34% of cases. The median shock index was 1 (IQR 0.8-1.1) before transfer and 0.9 (IQR 0.8-1.1) after transfer (p = 0.41). The median lactate level was 2.9 mmol/L (IQR 2.1-6.8) before, and 2.1 mmol/L (IQR 1.55-3.5) after transfer (p = 0.90). Forty-four patients underwent uterine artery embolization (64%), with an overall success rate of 93%. One patient died (1.4%), from a haemorrhagic shock of abdominal origin. CONCLUSIONS: Interhospital helicopter transfer of patients with postpartum haemorrhage to a tertiary hospital seems to be safe in our setting, despite a significant proportion of patients exhibiting signs of haemodynamic instability. Decision criteria would be helpful to better guide choices regarding the transfer of patients with postpartum haemorrhage.

Standardised data reporting from pre-hospital advanced airway management - a nominal group technique update of the Utstein-style airway template.

BACKGROUND: Pre-hospital advanced airway management with oxygenation and ventilation may be vital for managing critically ill or injured patients. To improve pre-hospital critical care and develop evidence-based guidelines, research on standardised high-quality data is important. We aimed to identify which airway data were most important to report today and to revise and update a previously reported Utstein-style airway management dataset. METHODS: We recruited sixteen international experts in pre-hospital airway management from Australia, United States of America, and Europe. We used a five-step modified nominal group technique to revise the dataset, and clinical study results from the original template were used to guide the process. RESULTS: The experts agreed on a key dataset of thirty-two operational variables with six additional system variables, organised in time, patient, airway management and system sections. Of the original variables, one remained unchanged, while nineteen were modified in name, category, definition or value. Sixteen new variables were added. The updated dataset covers risk factors for difficult intubation, checklist and standard operating procedure use, pre-oxygenation strategies, the use of drugs in airway management, airway currency training, developments in airway devices, airway management strategies, and patient safety issues not previously described. CONCLUSIONS: Using a modified nominal group technique with international airway management experts, we have updated the Utstein-style dataset to report standardised data from pre-hospital advanced airway management. The dataset enables future airway management research to produce comparable high-quality data across emergency medical systems. We believe this approach will promote research and improve treatment strategies and outcomes for patients receiving pre-hospital advanced airway management. TRIAL REGISTRATION: The Regional Committee for Medical and Health Research Ethics in Western Norway exempted this study from ethical review (Reference: REK-Vest/2017/260).

Function of the chemokine receptor CXCR4 in haematopoiesis and in cerebellar development.

Chemokines and their receptors are important in cell migration during inflammation, in the establishment of functional lymphoid microenvironments, and in organogenesis. The chemokine receptor CXCR4 is broadly expressed in cells of both the immune and the central nervous systems and can mediate migration of resting leukocytes and haematopoietic progenitors in response to its ligand, SDF-1. CXCR4 is also a major receptor for strains of human immunodeficiency virus-1 (HIV-1) that arise during progression to immunodeficiency and AIDS dementia. Here we show that mice lacking CXCR4 exhibit haematopoietic and cardiac defects identical to those of SDF-1-deficient mice, indicating that CXCR4 may be the only receptor for SDF-1. Furthermore, fetal cerebellar development in mutant animals is markedly different from that in wild-type animals, with many proliferating granule cells invading the cerebellar anlage. This is, to our knowledge, the first demonstration of the involvement of a G-protein-coupled chemokine receptor in neuronal cell migration and patterning in the central nervous system. These results may be important for designing strategies to block HIV entry into cells and for understanding mechanisms of pathogenesis in AIDS dementia.

A second promoter and enhancer element within the immunoglobulin heavy chain locus.

The joining of immunoglobulin gene segments during B cell development consists of a tightly regulated series of rearrangement steps. A variety of experiments have suggested that transcription is involved in activating the locus as substrate for the V(D)J recombinase. Here, we have characterized a region located immediately upstream of the most J-proximal D element (DQ52), which contains both promoter and enhancer activities preferentially active in precursors of B cells. Interestingly, this DQ52 regulatory element is inevitably deleted in fully rearranged H chain genes. We propose that it is involved in the early activation and rearrangement events at the IgH locus.

A survey of protein-DNA interaction sites within the murine immunoglobulin heavy chain locus reveals a particularly complex pattern around the DQ52 element.

The expression of immunoglobulin (Ig) genes is regulated at two levels: rearrangement of individual gene segments and transcription of continuous genes. To find transacting factors involved in mediating locus- and segment specific gene activation and expression, we surveyed a 3600-bp genomic region of the murine Ig heavy chain locus, spanning from the DQ52 element to the Ig heavy chain intron enhancer. We discovered nine, previously undescribed, protein-DNA complexes and estimated their individual binding-affinity preferences (Kr) by quantitative gel shift measurements. We observed one novel protein DNA interaction at the enhancer, two in the JH1 region and six within a 300-bp region immediately 5' to the DQ52 locus. The latter show a complex and specific binding pattern when comparing nuclear extracts derived from pre-B cells and fibroblasts. Further characterization of the interactions at the DQ52 locus by electron microscopy revealed the preferential formation of a protein complex binding to the DQ52 locus with pre B cell extracts. This behavior and the clustering of interaction sites 5' to the DQ52 element suggest that this region is involved in the regulation of heavy chain gene assembly.

DNA sequence of the coding region of the HLA-B44 gene.

An HLA-B44 cDNA clone was identified in a cDNA library constructed from an HLA-B44 homozygous cell line. The DNA sequence was determined and was found to contain the complete coding sequence but for (probably) the three N-terminal codons. Comparisons of the derived amino acid sequence with other HLA-A and -B locus amino acid sequences revealed four HLA-B44-specific substitutions including a new polymorphic site. Regions of strong sequence conservation for HLA-B-locus products were found at the nucleotide and amino acid levels.