Feasibility of quality indicators on prehospital advanced airway management in a physician-staffed emergency medical service: survey-based assessment of the provider point of view

OBJECTIVE

We aimed to determine the feasibility of quality indicators (QIs) for prehospital advanced airway management (PAAM) from a provider point of view.

DESIGN

The study is a survey based feasibility assessment following field testing of QIs for PAAM.

SETTING

The study was performed in two physician staffed emergency medical services in Switzerland.

PARTICIPANTS

42 of the 44 emergency physicians who completed at least one case report form (CRF) dedicated to the collection of the QIs on PAAM between 1 January 2019 and 31 December 2021 participated in the study.

INTERVENTION

The data required to calculate the 17 QIs was systematically collected through a dedicated electronic CRF.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were provider-related feasibility criteria: relevance and acceptance of the QIs, as well as reliability of the data collection. Secondary outcomes were effort to collect specific data and to complete the CRF.

RESULTS

Over the study period, 470 CRFs were completed, with a median of 11 per physician (IQR 4-17; range 1-48). The median time to complete the CRF was 7 min (IQR 3-16) and was considered reasonable by 95% of the physicians. Overall, 75% of the physicians assessed the set of QIs to be relevant, and 74% accepted that the set of QIs assessed the quality of PAAM. The reliability of data collection was rated as good or excellent for each of the 17 QIs, with the lowest rated for the following 3 QIs: duration of preoxygenation, duration of laryngoscopy and occurrence of desaturation during laryngoscopy.

CONCLUSIONS

Collection of QIs on PAAM appears feasible. Electronic medical records and technological solutions facilitating automatic collection of vital parameters and timing during the procedure could improve the reliability of data collection for some QIs. Studies in other services are needed to determine the external validity of our results.

Suspension syndrome: a scoping review and recommendations from the International Commission for Mountain Emergency Medicine (ICAR MEDCOM)

BACKGROUND

Suspension syndrome describes a multifactorial cardio-circulatory collapse during passive hanging on a rope or in a harness system in a vertical or near-vertical position. The pathophysiology is still debated controversially.

AIMS

The International Commission for Mountain Emergency Medicine (ICAR MedCom) performed a scoping review to identify all articles with original epidemiological and medical data to understand the pathophysiology of suspension syndrome and develop updated recommendations for the definition, prevention, and management of suspension syndrome.

METHODS

A literature search was performed in PubMed, Embase, Web of Science and the Cochrane library. The bibliographies of the eligible articles for this review were additionally screened.

RESULTS

The online literature search yielded 210 articles, scanning of the references yielded another 30 articles. Finally, 23 articles were included into this work.

CONCLUSIONS

Suspension Syndrome is a rare entity. A neurocardiogenic reflex may lead to bradycardia, arterial hypotension, loss of consciousness and cardiac arrest. Concomitant causes, such as pain from being suspended, traumatic injuries and accidental hypothermia may contribute to the development of the Suspension Syndrome. Preventive factors include using a well-fitting sit harness, which does not cause discomfort while being suspended, and activating the muscle pump of the legs. Expediting help to extricate the suspended person is key. In a peri-arrest situation, the person should be positioned supine and standard advanced life support should be initiated immediately. Reversible causes of cardiac arrest caused or aggravated by suspension syndrome, e.g., hyperkalaemia, pulmonary embolism, hypoxia, and hypothermia, should be considered. In the hospital, blood and further exams should assess organ injuries caused by suspension syndrome.

Hypothermic cardiac arrest patients admitted to hospital who were not rewarmed with extracorporeal life support: A retrospective study

Aims

Our goal was to study hypothermic cardiac arrest (CA) patients who were not rewarmed by Extracorporeal Life Support (ECLS) but were admitted to a hospital equipped for it. The focus was on whether the decisions of non-rewarming, meaning termination of resuscitation, were compliant with international guidelines based on serum potassium at hospital admission.

Methods

We retrospectively included all hypothermic CA who were not rewarmed, from three Swiss centers between 1st January 2000 and 2nd May 2021. Data were extracted from medical charts and assembled into two groups for analysis according to serum potassium. We identified the criteria used to terminate resuscitation. We also retrospectively calculated the HOPE score, a multivariable tool predicting the survival probability in hypothermic CA undergoing ECLS rewarming.

Results

Thirty-eight victims were included in the study. The decision of non-rewarming was compliant with international guidelines for 12 (33%) patients. Among the 36 patients for whom the serum potassium was measured at hospital admission, 24 (67%) had a value that - alone - would have indicated ECLS. For 13 of these 24 (54%) patients, the HOPE score was <10%, meaning that ECLS was not indicated. The HOPE estimation of the survival probabilities, when used with a 10% threshold, supported 23 (68%) of the non-rewarming decisions made by the clinicians.

Conclusions

This study showed a low adherence to international guidelines for hypothermic CA patients. In contrast, most of these non-rewarming decisions made by clinicians would have been compliant with current guidelines based on the HOPE score.

Performance Assessment of Out-of-Hospital Use of Pelvic Circumferential Compression Devices for Severely Injured Patients in Switzerland: A Nationwide Retrospective Cross-Sectional Study

BACKGROUND

Patients with severe pelvic fractures carry a greater risk of severe bleeding, and pelvic compression devices (PCCD) are used to stabilize the pelvis on the pre-hospital scene. The aim of this study was to describe the use of PCCD in the pre-hospital setting on a nationwide scale (Switzerland) and determine the sensitivity, specificity and rates of over- and under-triage of the current application practices. The secondary objective was to identify pre-hospital factors associated with unstable pelvic fractures.

METHODS

Retrospective cross-sectional study using anonymized patient data (1 January 2015-31 December 2020) from the Swiss Trauma Registry (STR). Based on AIS scores, patients were assigned a unique principal diagnosis among three categories (unstable pelvic fracture-stable pelvic fracture-other) and assessed for use or not of PCCD. Secondarily, patient characteristics, initial pre-hospital vital signs, means of pre-hospital transport and trauma mechanism were also extracted from the database.

RESULTS

2790 patients were included for analysis. A PCCD was used in 387 (13.9%) patients. In the PCCD group, 176 (45.5%) had an unstable pelvic fracture, 52 (13.4%) a stable pelvic fracture and 159 (41.1%) an injury unrelated to the pelvic region. In the group who did not receive a PCCD, 214 (8.9%) had an unstable pelvic fracture, 182 (7.6%) a stable pelvic fracture and 2007 (83.5%) an injury unrelated to the pelvic region. The nationwide sensitivity of PCCD application was 45.1% (95% CI 40.1-50.2), the specificity 91.2% (95% CI 90-92.3), with both over- and under-triage rates of 55%. The prevalence of unstable fractures in our population was 14% (390/2790). We identified female sex, younger age, lower systolic blood pressure, higher shock index, pedestrian hit and fall ≥3 m as possible risk factors for an unstable pelvic fracture.

CONCLUSIONS

Our results demonstrate a nationwide both over- and under-triage rate of 55% for out-of-hospital PCCD application. Female gender, younger age, lower blood pressure, higher shock index, pedestrian hit and fall >3 m are possible risk factors for unstable pelvic fracture, but it remains unclear if those parameters are relevant clinically to perform pre-hospital triage.

Takotsubo Cardiomyopathy Following Complete Avalanche Burial: A Case Report

Libersa, Marie, Louis Marxer, Ken Zafren, Stephane Oggier, Lorenzo Pucci, and Mathieu Pasquier. Takotsubo cardiomyopathy following complete avalanche burial: a case report. High Alt Med Biol. 24:149-151, 2023.-Takotsubo cardiomyopathy is a transient left ventricular dyskinesia triggered by a stressful physical or emotional event. We report a case of mid-ventricular Takotsubo stress cardiomyopathy in an avalanche victim. The patient was a 41-year-old woman who was completely buried under 1.2 m of snow for 30 minutes. On arrival at the hospital, she was conscious and hypothermic (core temperature 33.7°C). Her ECG showed rapid atrial fibrillation (142 beats/min) that converted to sinus rhythm after rewarming and administration of crystalloids. Echocardiography showed akinesia of the left mid-ventricle with a left ventricular ejection fraction of 41%. At 48-hour follow-up, echocardiography showed an almost complete recovery. During her hospital stay the patient was diagnosed with an acute stress disorder with symptoms of dissociation. She was discharged home after 5 days. At 2-week follow-up echocardiography was normal. Psychological follow-up was normal at 7 months. The physical and psychological stress of the avalanche, as well as hypothermia, were all possible triggers of Takotsubo cardiomyopathy.

The BISTIM study: a randomized controlled trial comparing dual ovarian stimulation (duostim) with two conventional ovarian stimulations in poor ovarian responders undergoing IVF

STUDY QUESTION

Is the total number of oocytes retrieved with dual ovarian stimulation in the same cycle (duostim) higher than with two consecutive antagonist cycles in poor responders?

SUMMARY ANSWER

Based on the number of total and mature oocytes retrieved in women with poor ovarian response (POR), there is no benefit of duostim versus two consecutive antagonist cycles.

WHAT IS KNOWN ALREADY

Recent studies have shown the ability to obtain oocytes with equivalent quality from the follicular and the luteal phase, and a higher number of oocytes within one cycle when using duostim. If during follicular stimulation smaller follicles are sensitized and recruited, this may increase the number of follicles selected in the consecutive luteal phase stimulation, as shown in non-randomized controlled trials (RCT). This could be particularly relevant for women with POR.

STUDY DESIGN, SIZE, DURATION

This is a multicentre, open-labelled RCT, performed in four IVF centres from September 2018 to March 2021. The primary outcome was the number of oocytes retrieved over the two cycles. The primary objective was to demonstrate in women with POR that two ovarian stimulations within the same cycle (first in the follicular phase, followed by a second in the luteal phase) led to the retrieval of 1.5 (2) more oocytes than the cumulative number of oocytes from two consecutive conventional stimulations with an antagonist protocol. In a superiority hypothesis, with power 0.8 alpha-risk 0.05 and a 35% cancellation rate, 44 patients were needed in each group. Patients were randomized by computer allocation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eighty-eight women with POR, defined using adjusted Bologna criteria (antral follicle count ≤5 and/or anti-Müllerian hormone ≤1.2 ng/ml) were randomized, 44 in the duostim group and 44 in the conventional (control) group. HMG 300 IU/day with flexible antagonist protocol was used for ovarian stimulation, except in luteal phase stimulation of the duostim group. In the duostim group, oocytes were pooled and inseminated after the second retrieval, with a freeze-all protocol. Fresh transfers were performed in the control group, frozen embryo transfers were performed in both control and duostim groups in natural cycles. Data underwent intention-to-treat and per-protocol analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no difference between the groups regarding demographics, ovarian reserve markers, and stimulation parameters. The mean (SD) cumulative number of oocytes retrieved from two ovarian stimulations was not statistically different between the control and duostim groups, respectively, 4.6 (3.4) and 5.0 (3.4) [mean difference (MD) [95% CI] +0.4 [-1.1; 1.9], P = 0.56]. The mean cumulative numbersof mature oocytes and total embryos obtained were not significantly different between groups. The total number of embryos transferred by patient was significantly higher in the control group 1.5 (1.1) versus the duostim group 0.9 (1.1) (P = 0.03). After two cumulative cycles, 78% of women in the control group and 53.8% in the duostim group had at least one embryo transfer (P = 0.02). There was no statistical difference in the mean number of total and mature oocytes retrieved per cycle comparing Cycle 1 versus Cycle 2, both in control and duostim groups. The time to the second oocyte retrieval was significantly longer in controls, at 2.8 (1.3) months compared to 0.3 (0.5) months in the duostim group (P < 0.001). The implantation rate was similar between groups. The cumulative live birth rate was not statistically different, comparing controls versus the duostim group, 34.1% versus 17.9%, respectively (P = 0.08). The time to transfer resulting in an ongoing pregnancy did not differ in controls 1.7 (1.5) months versus the duostim group, 3.0 (1.6) (P = 0.08). No serious adverse events were reported.

LIMITATIONS, REASONS FOR CAUTION

The RCT was impacted by the coronavirus disease 2019 pandemic and the halt in IVF activities for 10 weeks. Delays were recalculated to exclude this period; however, one woman in the duostim group could not have the luteal stimulation. We also faced unexpected good ovarian responses and pregnancies after the first oocyte retrieval in both groups, with a higher incidence in the control group. However, our hypothesis was based on 1.5 more oocytes in the luteal than the follicular phase in the duostim group, and the number of patients to treat was reached in this group (N = 28). This study was only powered for cumulative number of oocytes retrieved.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first RCT comparing the outcome of two consecutive cycles, either in the same menstrual cycle or in two consecutive menstrual cycles. In routine practice, the benefit of duostim in patients with POR regarding fresh embryo transfer is not confirmed in this RCT: first, because this study demonstrates no improvement in the number of oocytes retrieved in the luteal phase after follicular phase stimulation, in contrast to previous non-randomized studies, and second, because the freeze-all strategy avoids a pregnancy with fresh embryo transfer after the first cycle. However, duostim appears to be safe for women. In duostim, the two consecutive processes of freezing/thawing are mandatory and increase the risk of wastage of oocytes/embryos. The only benefit of duostim is to shorten the time to a second retrieval by 2 weeks if accumulation of oocytes/embryos is needed.

STUDY FUNDING/COMPETING INTERESTS

This is an investigator-initiated study supported by a research Grant from IBSA Pharma. N.M. declares grants paid to their institution from MSD (Organon France); consulting fees from MSD (Organon France), Ferring, and Merck KGaA; honoraria from Merck KGaA, General Electrics, Genevrier (IBSA Pharma), and Theramex; support for travel and meetings from Theramex, Merck KGaG, and Gedeon Richter; and equipment paid to their institution from Goodlife Pharma. I.A. declares honoraria from GISKIT and support for travel and meetings from GISKIT. G.P.-B. declares Consulting fees from Ferring and Merck KGaA; honoraria from Theramex, Gedeon Richter, and Ferring; payment for expert testimony from Ferring, Merck KGaA, and Gedeon Richter; and support for travel and meetings from Ferring, Theramex, and Gedeon Richter. N.C. declares grants from IBSA pharma, Merck KGaA, Ferring, and Gedeon Richter; support for travel and meetings from IBSA pharma, Merck KGaG, MSD (Organon France), Gedeon Richter, and Theramex; and participation on advisory board from Merck KGaA. E.D. declares support for travel and meetings from IBSA pharma, Merck KGaG, MSD (Organon France), Ferring, Gedeon Richter, Theramex, and General Electrics. C.P.-V. declares support for travel and meetings from IBSA Pharma, Merck KGaA, Ferring, Gedeon Richter, and Theramex. M.Pi. declares support for travel and meetings from Ferring, Gedeon Richetr, and Merck KGaA. M.Pa. declares honoraria from Merck KGaA, Theramex, and Gedeon Richter; support for travel and meetings from Merck KGaA, IBSA Pharma, Theramex, Ferring, Gedeon Richter, and MSD (Organon France). H.B.-G. declares honoraria from Merck KGaA, and Gedeon Richter and support for travel and meetings from Ferring, Merck KGaA, IBSA Pharma, MSD (Organon France), Theramex, and Gedeon Richter. S.G. and M.B. have nothing to declare.

TRIAL REGISTRATION NUMBER

Registration number EudraCT: 2017-003223-30. ClinicalTrials.gov identifier: NCT03803228.

TRIAL REGISTRATION DATE

EudraCT: 28 July 2017. ClinicalTrials.gov: 14 January 2019.

DATE OF FIRST PATIENT’S ENROLMENT

3 September 2018.

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.

Tamponnade cardiaque

La tamponnade cardiaque est une urgence vitale. Elle se définit comme une accumulation de liquide dans l’espace intrapéricardique, favorisant une augmentation de la pression intrapéricardique et une altération du remplissage cardiaque. Il s’agit d’une des causes du choc obstructif, et la rapidité d’installation détermine le degré d’instabilité hémodynamique. La morbidité et la mortalité dépendent de la rapidité du diagnostic et de sa prise en charge. Peu fréquemment, l’étiologie est tumorale. Ce type d’étiologie se traduit le plus souvent par des tableaux cliniques d’installation lente et progressive. C’est le cas du sujet qui est présenté dans cet article : un homme de 50 ans sans suivi médical et consommateur d’alcool et de tabac, vivant dans un contexte social difficile. L’issue fatale du cas clinique témoigne de la gravité du tableau de présentation initiale. L’électrocardiogramme peut révéler des signes caractéristiques comme le microvoltage du QRS et l’alternance électrique. La méthode standard pour détecter un épanchement péricardique est l’échocardiographie : le diagnostic de tamponnade cardiaque requiert la présence de collapsus complet du coeur droit et dans les cas plus graves des cavités gauches. Les compétences de l’urgentiste en termes d’échographie permettent un diagnostic plus rapide et précis. Le traitement de la tamponnade cardiaque repose principalement sur le soutien hémodynamique (administration volumique et traitement des éventuels troubles du rythme secondaires) en urgence. Cependant, le traitement définitif reste le drainage du liquide accumulé par péricardiocentèse ou par approche chirurgicale.

Prevalence and clinical significance of point of care elevated lactate at emergency admission in older patients: a prospective study

OBJECTIVE

Patients who are over 65 years old represent up to 24% of emergency department (ED) admissions. They are at increased risk of under-triage due to impaired physiological responses. The primary objective of this study was to assess the prevalence of elevated lactate by point of care testing (POCT) in this population. The secondary objective was to assess the additional value of lactate level in predicting an early poor outcome, as compared to and combined with common clinical scores and triage scales.

METHODS

This monocentric prospective study recruited ED patients who were over 65 years old between July 19th 2019 and June 17th 2020. Patients consulting for seizures or needing immediate assessment were excluded. POCT lactates were considered elevated if ≥ 2.5 mmol/L. A poor outcome was defined based on certain complications or therapeutic decisions.

RESULTS

In total, 602 patients were included; 163 (27.1%) had elevated lactate and 44 (7.3%) had a poor outcome. There was no association between poor outcome and lactate level. Modified Early Warning Score (MEWS) was significantly associated with poor outcome, alongside National Early Warning Score (NEWS). Logistic regression also associated lactate level combined with MEWS and poor outcome.

CONCLUSION

The prevalence of elevated lactate was 27.1%. Lactate level alone or combined with different triage scales or clinical scores such as MEWS, NEWS and qSOFA was not associated with prediction of a poor outcome. MEWS alone performed best in predicting poor outcome. The usefulness of POCT lactate measurement at triage is questionable in the population of 65 and above.

Outcome prediction for hypothermic patients in cardiac arrest

The 5A score predicts in-hospital mortality of patients suffering from accidental hypothermia, including those not in cardiac arrest. The HOPE score was specifically developed to predict survival for the subgroup of hypothermic patients in cardiac considered for extracorporeal life support rewarming. The C-statistic in the external validation study of the HOPE score was 0.825 (95% CI: 0.753–0.897), confirming its excellent discrimination. In addition, its good calibration allows for a reliable interpretation of the corresponding survival probability after rewarming. The HOPE score should be used for predicting outcome and selecting hypothermic patients in cardiac arrest for rewarming.

O-068 The BISTIM study: first RCT comparing dual ovarian stimulation on the same cycle (duostim) vs 2 conventional ovarian stimulations in poor ovarian responders undergoing IVF

Study question

Is the number of cumulated oocytes with dual ovarian stimulation on the same cycle (duostim) higher compared to 2 consecutive antagonist cycles in poor responders?

Summary answer

Considering the number of total and mature oocytes collected in poor ovarian responders, there is no benefit of duostim vs two consecutive antagonist cycles.

What is known already

Several waves of follicular development exist on the same cycle. Recent studies have shown the ability to obtain oocytes with equivalent quality in the luteal phase, even after a previous ovarian stimulation in the follicular phase. During stimulation, smaller follicles are recruited and sensitized, which may increase the selection of follicles available on the second stimulation. In poor ovarian responders (POR) this potentialization may have a great interest, as 2 stimulations on the same cycle could give a higher number of oocytes compared to two conventional stimulations. However, these preliminary data need to be confirmed with a randomized controlled trial.

Study design, size, duration

This is a multicenter, open-labeled randomized control trial (2018, september – 2021, march). The primary objective was to demonstrate that two ovarian stimulations within the same cycle (first in the follicular phase, followed by a second in the luteal phase) lead to the retrevial of 1.5 more oocytes than the cumulative number of oocytes from two consecutive conventional stimulation, in POR women. According to this hypothesis, 44 patients were needed in each group.

Participants/materials, setting, methods

88 POR women, defined with Bologna criteria (AFC≤5 and/or AMH≤1.2ng/ml and ≤3 oocytes if previous IVF) were randomized, 44 in duostim group (D) and 44 in conventional group (C). FertistartKit® 300IU/day with antagonist protocol was used except in luteal phase stimulation of group D. In group D, oocytes were pooled and inseminated after the second retrieval, with freeze all embryos. Fresh transfer was performed in group C. The analysis is presented in intention to treat.

Main results and the role of chance

There was no difference between the groups regarding demographics, ovarian reserve markers (AFC, AMH) and stimulation parameters. The mean number of cumulated oocytes retrieved with 2 ovarian stimulation was not statistically different in group D and C, respectively 5.0+/-3.4 and 4.6+/-3.4 (p = 0.56). The mean number of cumulated mature oocytes was not statistically different, 3.7+/-3.3 in group D vs 3.1+/-3.0 in group C (p = 0.38). The mean number of embryos was significantly lower in the group D, 0.8+/-1.3 vs group C 1.6+/-1.3 (p &lt; 0.01). There was no statistical difference of the mean number of oocytes retrieved per cycle in cycle 1 vs cycle 2 in both group D and C. The delay, between the first and the second day 1 of stimulation was statistically different in group D 14.4 days (10-19) vs group C 90.6 (28-232). The ongoing pregnancy rate in group D 17.9% (7/39) was not statistically different with group C 29.3% (12/41), (p = 0.23). And the mean time to ongoing pregnancy tends to be longer in group D (144 days) vs group C (115 days) but was not statistically different (p = 0.21).

Limitations, reasons for caution

The RCT was impacted by Covid pandemia and stop of IVF activities for 10 weeks. Delays were recalculated to exclude this period, however one women in group D cannot have the luteal stimulation. We also faced unexpected good ovarian responses and pregnancies after the first oocyte pick-up in group C.

Wider implications of the findings

In routine practice, the benefit of duostim in patients with POR is not confirmed. Firstly, because there is no potentialization on the number of oocyte retrieved in luteal phase after follicular phase stimulation. Secondly, because the freeze all strategy avoids a pregnancy with fresh embryo transfer after the first cycle.

Trial registration number

2017-A00498-45

[Dydrogesterone versus micronized vaginal progesterone as luteal phase support after fresh embryo transfer in IVF]

OBJECTIVES

The objective of the study was to compare the live birth rate and miscarriage rate after fresh embryo transfer (Fresh ET) when patients are treated either with oral dydrogesterone or micronized vaginal progesterone (MVP) as luteal phase support (LPS). The vaginal route is still preferred, despite the discomfort for the patients and recent RCTs showing similar results for dydrogesterone and MVP.

METHODS

All 556 consecutive Fresh ET after autologous IVF procedure, from December 2011 to March 2013 in one centre in France were included. Patients were treated either with dydrogesterone 10mg every 12hours (n=267) or MVP 200mg every 12hours (n=289), the physician's arbitrary choice on the day of the oocyte aspiration procedure.

RESULTS

The groups were comparable regarding the demographic data and stimulation protocols, except for the rank of the oocyte pickup procedure [1.54±0.80 vs. 1.74±0.96, (P=0.01)], with no significant difference in live birth rates (22.4% vs. 23.8%, P=0.77) and miscarriage rates (4.1% vs. 5.5%, P=0.55) for dydrogesterone vs. MVP respectively. The results were similar in a good prognosis patients' subgroup.

CONCLUSIONS

LPS with either dydrogesterone or MVP after Fresh ET showed similar live birth rates and miscarriage rates. The benefits of the oral over vaginal route might be higher tolerance and possibly better compliance. Dydrogesterone seems to be a safe treatment, but its long-term innocuity needs to be further proven.

Avalanche survival depends on the time of day of the accident: A retrospective observational study

INTRODUCTION

We aimed to investigate the relationship between the time of the day and the probability of survival of completely buried avalanche victims. We explored the frequency of avalanche burials occurring after sunset, and described victims' characteristics, duration of burial and rescue circumstances compared to daytime avalanches.

METHODS

In this retrospective, observational study, we analysed avalanche data from the registry of the Swiss Institute for Snow and Avalanche Research, from 1998 to 2020.

RESULTS

A total of 3,892 avalanche victims were included in the analysis, with 72 of the accidents (1.85%) occurring in the nighttime. Nearly 50% of the victims involved in nighttime avalanche accidents were completely buried, compared to about 25% of victims in daytime avalanches. Completely buried victims were rescued by a companion less often at night than in the daytime (15% vs. 51%, p<.001). The search and rescue of completely buried avalanche victims took longer during the nighttime compared to the daytime (median 89 min vs 20 min, p=.002). The probability of survival decreased as the day progressed; it was highest at around midday (63.0%), but decreased at sunset (40.4%) and was the lowest at midnight (28.7%).

CONCLUSIONS

Avalanche accidents at night are a rare event, and probability of survival after complete burial is lower during the nighttime compared to the daytime. The most relevant reason for this is the longer duration of burial, which is explained in part by the lower rate of companion rescue and the lower rate of victim localisation with an avalanche transceiver.

Extracorporeal Life Support in Accidental Hypothermia with Cardiac Arrest-A Narrative Review

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.

Prehospital Use of Ultrathin Reflective Foils

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.

Accidental Hypothermia: 2021 Update

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.

Higher pre-hospital anaesthesia case volumes result in lower mortality rates: implications for mass casualty care

Senior physicians with a higher pre-hospital anaesthesia case volume have higher first-pass tracheal intubation success rates, shorter on-site times, and lower patient mortality rates than physicians with lower case volumes. A senior physician's skill set includes the basics of management of airway and breathing (ventilating and oxygenating the patient), circulation, disability (anaesthesia), and environment (especially maintaining core temperature). Technical rescue skills may be required to care for patients requiring pre-hospital airway management especially in hazardous environments, such as road traffic accidents, chemical incidents, terror attacks or warfare, and natural disasters. Additional important tactical skills in mass casualty situations include patient triage, prioritising, allocating resources, and making transport decisions.

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.

Resuscitation of an Unconscious Victim of Accidental Hypothermia in 1805

In 1805, W.D., a 16-y-old boy, became hypothermic after he was left alone on a grounded boat in Leith Harbour, near Edinburgh, Scotland. He was brought to his own house and resuscitated with warm blankets, smelling salts, and massage by Dr. George Kellie. W.D. made an uneventful recovery. We discuss the pathophysiology and treatment of accidental hypothermia, contrasting treatment in 1805 with treatment today. W.D. was hypothermic when found by passersby. Although he appeared dead, he was rewarmed with help from Dr. Kellie and his assistants over 200 y ago using simple methods. One concept that has not changed is the critical importance of attempting resuscitation, even if it seems to be futile. Don't give up!

Random antral follicle count performed on any day of the menstrual cycle has the same predictive value as AMH for good ovarian response in IVF cycles

OBJECTIVE

To determine whether the predictive value of AFC for ovarian response to stimulation for IVF depends on the day of the menstrual cycle when ultrasound is performed.

METHODS

410 women undergoing their first IVF cycle were included. All the women had AFC performed twice. The first measurement, random AFC (r-AFC), was performed during the fertility workup whatever the day of their menstrual cycle. Three groups were constituted according to the period of ultrasound performance: at early follicular phase i.e., day 1 to day 6 (eFP-AFC); at mid follicular phase i.e., day 7 to 12 (mFP-AFC) and at luteal phase i.e., day 13 or after (LP-AFC). A second AFC measurement was performed before the start of the ovarian stimulation (SD1-AFC). AMH dosing was done in the early follicular phase.

RESULTS

Random AFC (r-AFC) was correlated to AMH (r = 0.69; p<0.001), SD1-AFC (r = 0.75; p<0.001) and number of oocytes retrieved (r = 0.49; p<0.001). When regarding AFC depending on the cycle day group, the correlation with AMH was 0.65, 0.66 and 0.85 for the eFP-AFC, the mFP-AFC and the LP-AFC respectively (all p were <0.001). The ROC analysis showed the same predictive value for good ovarian response (more than 6 oocytes retrieved) for the eFP-AFC, mFP-AFC and LP-AFC (AUC 0.73, 0.75 and 0.84 respectively; p = 0.28). The AUC of r-AFC (0.76) were similar to those of AMH (0.74) and SD1-AFC (0.74) (p = 0.21 and 0.92 respectively).

CONCLUSION

AFC is strongly correlated with AMH and highly predictive of good ovarian response during the whole menstrual cycle.

Prognosis of Hypothermic Patients Undergoing ECLS Rewarming-Do Alterations in Biochemical Parameters Matter?

Background: While ECLS is a highly invasive procedure, the identification of patients with a potentially good prognosis is of high importance. The aim of this study was to analyse changes in the acid-base balance parameters and lactate kinetics during the early stages of ECLS rewarming to determine predictors of clinical outcome. Methods: This single-centre retrospective study was conducted at the Severe Hypothermia Treatment Centre at John Paul II Hospital in Krakow, Poland. Patients ≥18 years old who had a core temperature (Tc) < 30 °C and were rewarmed with ECLS between December 2013 and August 2018 were included. Acid-base balance parameters were measured at ECLS implantation, at Tc 30 °C, and at 2 and 4 h after Tc 30 °C. The alteration in blood lactate kinetics was calculated as the percent change in serum lactate concentration relative to the baseline. Results: We included 50 patients, of which 36 (72%) were in cardiac arrest. The mean age was 56 ± 15 years old, and the mean Tc was 24.5 ± 12.6 °C. Twenty-one patients (42%) died. Lactate concentrations in the survivors group were significantly lower than in the non-survivors at all time points. In the survivors group, the mean lactate concentration decreased −2.42 ± 4.49 mmol/L from time of ECLS implantation until 4 h after reaching Tc 30 °C, while in the non-survivors’ group (p = 0.024), it increased 1.44 ± 6.41 mmol/L. Conclusions: Our results indicate that high lactate concentration is associated with a poor prognosis for hypothermic patients undergoing ECLS rewarming. A decreased value of lactate kinetics at 4 h after reaching 30 °C is also associated with a poor prognosis.

The Efficacy of Renal Replacement Therapy for Rewarming of Patients in Severe Accidental Hypothermia-Systematic Review of the Literature

Background: Renal replacement therapy (RRT) can be used to rewarm patients in deep hypothermia. However, there is still no clear evidence for the effectiveness of RRT in this group of patients. This systematic review aims to summarize the rewarming rates during RRT in patients in severe hypothermia, below or equal to 32 °C. Methods: This systematic review was registered in the PROSPERO International Prospective Register of Systematic Reviews (identifier CRD42021232821). We searched Embase, Medline, and Cochrane databases using the keywords hypothermia, renal replacement therapy, hemodialysis, hemofiltration, hemodiafiltration, and their abbreviations. The search included only articles in English with no time limit, up until 30 June 2021. Results: From the 795 revised articles, 18 studies including 21 patients, were selected for the final assessment and data extraction. The mean rate of rewarming calculated for all studies combined was 1.9 °C/h (95% CI 1.5–2.3) and did not differ between continuous (2.0 °C/h; 95% CI 0.9–3.0) and intermittent (1.9 °C/h; 95% CI 1.5–2.3) methods (p > 0.9). Conclusions: Based on the reviewed literature, it is currently not possible to provide high-quality recommendations for RRT use in specific groups of patients in accidental hypothermia. While RRT appears to be a viable rewarming strategy, the choice of rewarming method should always be determined by the specific clinical circumstances, the available resources, and the current resuscitation guidelines.

Quality Indicators for Avalanche Victim Management and Rescue

Decisions in the management and rescue of avalanche victims are complex and must be made in difficult, sometimes dangerous, environments. Our goal was to identify indicators for quality measurement in the management and rescue of avalanche victims. The International Commission for Mountain Emergency Medicine (ICAR MedCom) convened a group of internal and external experts. We used brainstorming and a five-round modified nominal group technique to identify the most relevant quality indicators (QIs) according to the National Quality Forum Measure Evaluation Criteria. Using a consensus process, we identified a set of 23 QIs to measure the quality of the management and rescue of avalanche victims. These QIs may be a valuable tool for continuous quality improvement. They allow objective feedback to rescuers regarding clinical performance and identify areas that should be the foci of further quality improvement efforts in avalanche rescue.

Modelling transport time to trauma centres and 30-day mortality in road accidents in Switzerland: an exploratory study

BACKGROUND

Rapid access to a trauma centre for severely injured road accident victims, conceptualised as the Golden Hour, links access time to definitive treatment within 1 hour of trauma with reduced risks of morbidity and mortality. Access times have not been studied in Switzerland. The aim of this work was to model the transport time by ambulance of seriously injured road traffic accident victims to one of the 12 trauma centres in Switzerland and to investigate whether this time influenced mortality.

METHODS

Isochronous travel curves in 10-minute increments were modelled around each of the 12 Swiss trauma centres to assess travel times at the Swiss national level, based on the shortest travel time from the location of a serious road accident to the nearest trauma centre. We used the national database of the Federal Roads Office, which provided the geolocation of these accidents occurring between 2011 and 2017. The association between mortality and transport time to the nearest trauma centre was then analysed.

RESULTS

The current distribution of trauma centres allowed access time within the Golden Hour for accidents occurring on the Swiss plateau, but the time was more prolonged in the Alps or the Jura. An association existed between mortality and prehospital transport time from the site of an accident to the nearest trauma centre. For each additional 10-minute isochrone, an average increase of 0.4% in mortality was observed.

CONCLUSION

This work showed an adequate distribution of trauma centres in Switzerland and suggests a positive relationship between transport time to the nearest trauma centre and mortality. The numerous confounding factors not systematically collected in publicly available databases limit the robustness of our results. This study confirms the importance of having a national trauma registry to allow quality analyses to guide public health decisions.

Clinician miscalibration of survival estimate in hypothermic cardiac arrest: HOPE-estimated survival probabilities in extreme cases

AIM

Patients with hypothermic cardiac arrest may survive with an excellent outcome after extracorporeal life support rewarming (ECLSR). The HOPE (Hypothermia Outcome Prediction after ECLS) score is recommended to guide the in-hospital decision on whether or not to initiate ECLSR in patients in cardiac arrest following accidental hypothermia. We aimed to assess the HOPE-estimated survival probabilities for a set of survivors of hypothermic cardiac arrest who had extreme values for the variables included in the HOPE score.

METHODS

Survivors were identified and selected through a systematic literature review including case reports. We calculated the HOPE score for each patient who presented extraordinary clinical parameters.

RESULTS

We identified 12 such survivors. The HOPE-estimated survival probability was ≥10% for all (n = 11) patients for whom we were able to calculate the HOPE score.

CONCLUSION

Our study confirms the robustness of the HOPE score for outliers and thus further confirms its external validity. These cases also confirm that hypothermic cardiac arrest is a fundamentally different entity than normothermic cardiac arrest. Using HOPE for extreme cases may support the proper calibration of a clinician's prognosis and therapeutic decision based on the survival chances of patients with accidental hypothermic cardiac arrest.

P–599 random antral follicle count, performed at any day of the menstrual cycle, demonstrates the same predictive value for ovarian response in in vitro fertilization cycles

Study question

Does antral follicle count (AFC) retains its predictive value for ovarian response to stimulation for in vitro fertilization (IVF) throughout the whole menstrual cycle?

Summary answer

AFC is strongly correlated to anti-mullerian hormone (AMH) and highly predictive of good ovarian response whatever the day of cycle the ultrasound is performed.

What is known already

Usually performed in the early follicular phase (at day 2–3 of the menstrual cycle), AFC and AMH are the most accurate markers of ovarian reserve. They are routinely used to predict ovarian response to ovarian stimulation for IVF and eventually to individualize the gonadotropin starting dose.

Study design, size, duration

Retrospective cohort study performed between January, 2017 and December, 2019.

Participants/materials, setting, methods

410 consecutive women aged 20 to 42 years were included. Random AFC (r-AFC) was performed during the fertility workup whatever the day of their menstrual cycle was: early follicular phase i.e. day 1 to day 6 (eFP-AFC), mid follicular phase i.e. day 7 to 12 (mFP-AFC) and luteal phase i.e. day 13 or after (LP-AFC). A second AFC was performed before the start of the stimulation (SD1-AFC). AMH was measured in the early follicular phase.

Main results and the role of chance

Random AFC (r-AFC) was correlated to AMH (r = 0.692; p &lt; 0.001), SD1-AFC (r = 0.756; p &lt; 0.001) and number of oocytes retrieved (r = 0.491; p &lt; 0.001). When regarding AFC depending on the cycle day group, the correlation with AMH was significantly higher for the LP-AFC, (LP-AFC) (r = 0.853) than for the eFP-AFC (r = 0.657; p &lt; 0.001) and for the mFP-AFC (r = 0.668). The correlation with SD1-AFC was similar regardless of the time of performance of r-AFC (r = 0.739, 0.783, 0.733, respectively for eFP, mFP and LP-AFC). Moreover, the ROC analysis showed the same predictive value for good ovarian response (more than 6 oocytes retrieved) for the eFP-AFC, mFP-AFC and LP-AFC (AUC 0.73, 0.75 and 0.84 respectively) as well as for AMH and SD1-AFC (AUC 0.74 and 0.74, respectively).

Limitations, reasons for caution

This is a retrospective analysis, however data were prospectively collected and the method for ultrasound acquisition of AFC was standardized.

Wider implications of the findings: The absence of significant variation of AFC across the menstrual cycle allows to its random performance. Ultrasound performed besides early follicular phase discloses informations on ovaries, the uterus and the endometrium. It is more comfortable and convenient for women and physicians by limiting targeted appointment during menstruation and reiterated examination.

Trial registration number

Not applicable

P–730 “Fertility Check Up”: A proposal for assessment of women’s fertility potential. Analysis and evaluation of the first 200 women

Study question

Is there an interest in offering a fertility assessment to all women, with or without proven infertility, whatever their personal situation or parental project ?

Summary answer

Assessing the fertility of all women allows us to inform and advise them, in order to optimize their chances to achieve their parenting project.

What is known already

In a society where the age of childbearing is increasing and where women want to be able to postpone their pregnancies and to plan their parenting plan, there is no medical recommendation to assess fertility of women who are single or who do not have proven infertility.

Study design, size, duration

We implemented a new proposal in our reproductive medicine department, the “Fertility Check Up” (FCU), allowing any woman, whatever her personal situation or parental project, to benefit from an evaluation of her fertility, as well as personalized information and advice, to optimize the realization of her life plan.

Participants/materials, setting, methods

The FCU is carried out on female volunteers who do not need to be referred by a doctor. The fertility evaluation is performed by a self-questionnaire and an “all-in-one” ultrasound examination (Fertiliscan) including a complete pelvic ultrasound with a hysterosalpingo-foam-sonography (Hyfosy); this examination allows an anatomical and functional evaluation of the female reproductive system, in one step. Women then benefit from a personalized interview with a fertility specialist.

Main results and the role of chance

In the first year, 200 women aged 24 to 48 years old benefited from this examination, 56% of whom had never attempted to conceive. Anomalies found included: tubal diseases (29%), congenital or acquired uterine anomalies (11,5%), and endometriosis (6,5%). We concluded to a low ovarian reserve for age in 14% of cases. 84% of women say they felt little or no discomfort during the Fertiliscan. A questionnaire was sent to women 6 months after the FCU: among the 85 women with a desire for pregnancy at the time of the FCU, 29.1% obtained a pregnancy, and 36% began ART procedures. Among the women who had no plans for pregnancy, 50% stated that the completion of the FCU had modified their personal or professional plans regarding a possible desire for future pregnancy.

Limitations, reasons for caution

Women are informed that the FCU gives them indications about their theoretical chances of pregnancy, but that there is no way to be sure that a woman will ever bear a child, as 10% of infertilities remain idiopathic.

Wider implications of the findings: The proposal of fertility assessment for women, whether infertile or not, with or without immediate pregnancy plans, allows for information, advice and treatment if necessary. Women are better informed about their own fertility, and can get the best chances to achieve their parental project, with, or ideally without, assisted-reproductive-techniques.

Trial registration number

Not applicable

O-107 Searching for the optimal number of oocytes to reach a life birth following in vitro fertilization: a systematic review with meta-analysis

Study question

To investigate the relationship between the number of oocytes and both the live birth rate after fresh embryo transfer and the cumulative live birth rate.

Summary answer

Above a 15-oocyte threshold, live birth rate (LBR) following fresh transfer plateaus, whereas a continuous increase in cumulative live birth rate (CLBR) is observed.

What is known already

Several lines of evidence indicate that number of oocytes represents a key point for in vitro fertilization (IVF) success. However, consensus is lacking regarding the optimal number of oocytes for expecting a live birth. This is a key question because it might impact the way practitioners initiate and adjust COS regimens.

Study design, size, duration

A systematic review and meta-analysis was performed. MEDLINE, EMBASE, and Cochrane Library were searched for studies published between January 01, 2004, and August 31, 2019 using the search terms: “(intracytoplasmic sperm injection or icsi or ivf or in vitro fertilization or fertility preservation)” and “(oocyte and number)” and “(live birth)”.

Participants/materials, setting, methods

Two independent reviewers carried out study selection, quality assessment using the adapted Newcastle-Ottawa Quality Assessment Scales, bias assessment using ROBIN-1 tools, and data extraction according to Cochrane methods. Independent analyses were performed according to the outcome (LBR and CLBR). The mean-weighted threshold of optimal oocyte number was estimated from documented thresholds, followed by a one-stage meta-analysis on articles with documented or estimable relative risks.

Main results and the role of chance

After reviewing 843 records, 64 full-text articles were assessed for eligibility. A total of 36 studies were available for quantitative syntheses. Twenty-one and 18 studies were included in the meta-analyses evaluating the relationship between the number of retrieved oocytes and LBR or CLBR, respectively. Given the limited number of investigations considering mature oocytes, association between the number of metaphase II oocytes and IVF outcomes could not be investigated. Concerning LBR, 7 (35.0%) studies reported a plateau effect, corresponding to a weighted mean of 14.4 oocytes. The pooled dose-response association between the number of oocytes and LBR showed a non-linear relationship, with a plateau beyond 15 oocytes. For CLBR, 4 (19.0%) studies showed a plateau effect, corresponding to a weighted mean of 19.3 oocytes. The meta-analysis of the relationship between the number of oocytes and CLBR found a non-linear relationship, with a continuous increase in CLBR, including for high oocyte yields.

Limitations, reasons for caution

Statistical models show a high degree of deviance, especially for high numbers of oocytes. Further investigations are needed to assess the generalization of those results to frozen mature oocytes, especially in a fertility preservation context, and to evaluate the impact of female age.

Wider implications of the findings

Above a 15-oocyte threshold, LBR following fresh transfer plateaus, suggesting that the freeze-all strategy should probably be performed. In contrast, the continuous increase in CLBR suggests that high numbers of oocytes could be offered to improve the chances of cumulative live births, after evaluating the benefit–risk balance.

Trial registration number

Not applicable

The efficiency of continuous renal replacement therapy for rewarming of patients in accidental hypothermia--An experimental study

Severe accidental hypothermia carries high mortality and morbidity and is often treated with invasive extracorporeal methods. Continuous veno-venous hemodiafiltration (CVVHDF) is widely available in intensive care units. We sought to provide theoretical basis for CVVHDF use in rewarming of hypothermic patients. CVVHDF system was used in the laboratory setting. Heat balance and transferred heat units were evaluated for the system without using blood. We used 5L of crystalloid solution at the temperature of approximately 25°C, placed in a thermally insulated tank (representing the "central compartment" of a hypothermic patient). Time of warming the central compartment from 24.9 to 30.0°C was assessed with different flow combinations: "blood" (central compartment fluid) 50 or 100 or 150 mL/min, dialysate solution 100 or 1500 mL/h, and substitution fluid 0 or 500 mL/h. The total circulation time was 1535 minutes. There were no differences between heat gain values on the filter depending on blood flow (P = .53) or dialysate flow (P = .2). The mean heating time for "blood" flow rates 50, 100, and 150 mL/min was 113.7 minutes (95% CI, 104.9-122.6 minutes), 83.3 minutes (95% CI, 76.2-90.3 minutes), and 74.7 minutes (95% CI, 62.6-86.9 minutes), respectively (P < .01). The respective median rewarming rate for different "blood" flows was 3.6°C/h (IQR, 3.0-4.2°C/h), 4.8 (IQR, 4.2-5.4°C/h), and 5.4 (IQR, 4.8-6.0°C/h), respectively (P < .01). The dialysate flow did not affect the warming rate. Based on our experimental model, CVVHDF may be used for extracorporeal rewarming, with the rewarming rates increasing achieved with higher blood flow rates.

Management of respiratory distress following prehospital implementation of noninvasive ventilation in a physician-staffed emergency medical service: a single-center retrospective study

BACKGROUND

Noninvasive ventilation (NIV) is recognized as first line ventilatory support for the management of acute pulmonary edema (APE) and chronic obstructive pulmonary disease (COPD) exacerbations. We aimed to study the prehospital management of patients in acute respiratory distress with an indication for NIV and whether they received it or not.

METHODS

This retrospective study included patients ≥18 years old who were cared for acute respiratory distress in a prehospital setting. Indications for NIV were oxygen saturation (SpO₂) <90% and/or respiratory rate (RR) >25/min with a presumptive diagnosis of APE or COPD exacerbation. Study population characteristics, initial and at hospital vital signs, presumptive and definitive diagnosis were analyzed. For patients who received NIV, dyspnea level was evaluated with a dyspnea verbal ordinal scale (D-VOS, 0-10) and arterial blood gas (ABG) values were obtained at hospital arrival.

RESULTS

Among the 187 consecutive patients included in the study, most (n = 105, 56%) had experienced APE or COPD exacerbation, and 56 (30%) received NIV. In comparison with patients without NIV, those treated with NIV had a higher initial RR (35 ± 8/min vs 29 ± 10/min, p < 0.0001) and a lower SpO₂ (79 ± 10 vs 88 ± 11, p < 0.0001). The level of dyspnea was significantly reduced for patients treated with NIV (on-scene D-VOS 8.4 ± 1.7 vs 4.4 ± 1.8 at admission, p < 0.0001). Among the 131 patients not treated with NIV, 41 (31%) had an indication. In the latter group, initial SpO₂ was 80 ± 10% in the NIV group versus 86 ± 11% in the non-NIV group (p = 0.0006). NIV was interrupted in 9 (16%) patients due to either discomfort (n = 5), technical problem (n = 2), persistent desaturation (n = 1), or vomiting (n = 1).

CONCLUSIONS

The results of this study contribute to a better understanding of the prehospital management of patients who present with acute respiratory distress and an indication for NIV. NIV was started on clinically more severe patients, even if predefined criteria to start NIV were present. NIV allows to improve vital signs and D-VOS in those patients. A prospective study could further elucidate why patients with a suspected diagnosis of APE and COPD are not treated with NIV, as well as the clinical impact of the different strategies.

TRIAL REGISTRATION

The study was approved by our institutional ethical committee ( CER-VD 2020-01363 ).

Survival probability in avalanche victims with long burial (≥60 min): A retrospective study

BACKGROUND

The survival of completely buried victims in an avalanche mainly depends on burial duration. Knowledge is limited about survival probability after 60 min of complete burial.

AIM

We aimed to study the survival probability and prehospital characteristics of avalanche victims with long burial durations.

METHODS

We retrospectively included all completely buried avalanche victims with a burial duration of ≥60 min between 1997 and 2018 in Switzerland. Data were extracted from the registry of the Swiss Institute for Snow and Avalanche Research and the prehospital medical records of the physician-staffed helicopter emergency medical services. Avalanche victims buried for ≥24 h or with an unknown survival status were excluded. Survival probability was estimated by using the non-parametric Ayer-Turnbull method and logistic regression. The primary outcome was survival probability.

RESULTS

We identified 140 avalanche victims with a burial duration of ≥60 min, of whom 27 (19%) survived. Survival probability shows a slight decrease with increasing burial duration (23% after 60 min, to <6% after 1400 min, p = 0.13). Burial depth was deeper for those who died (100 cm vs 70 cm, p = 0.008). None of the survivors sustained CA during the prehospital phase.

CONCLUSIONS

The overall survival rate of 19% for completely buried avalanche victims with a long burial duration illustrates the importance of continuing rescue efforts. Avalanche victims in CA after long burial duration without obstructed airway, frozen body or obvious lethal trauma should be considered to be in hypothermic CA, with initiation of cardiopulmonary resuscitation and an evaluation for rewarming with extracorporeal life support.

Clinical staging of accidental hypothermia: The Revised Swiss System: Recommendation of the International Commission for Mountain Emergency Medicine (ICAR MedCom)

Clinical staging of accidental hypothermia is used to guide out-of-hospital treatment and transport decisions. Most clinical systems utilize core temperature, by measurement or estimation, to stage hypothermia, despite the challenge of obtaining accurate field measurements. Recent studies have demonstrated that field estimation of core temperature is imprecise. We propose a revision of the original Swiss Staging system. The revised system uses the risk of cardiac arrest, instead of core temperature, to determine the staging level. Our revised system simplifies assessment by using the level of responsiveness, based on the AVPU scale, and by removing shivering as a stage-defining sign.

Vital Signs in Accidental Hypothermia

Pasquier, Mathieu, Evelien Cools, Ken Zafren, Pierre-Nicolas Carron, Vincent Frochaux, and Valentin Rousson. Vital signs in accidental hypothermia. High Alt Med Biol. 22: 142-147, 2021. Background: Clinical indicators are used to stage hypothermia and to guide management of hypothermic patients. We sought to better characterize the influence of hypothermia on vital signs, including level of consciousness, by studying cases of patients suffering from accidental hypothermia. Materials and Methods: We retrospectively included patients aged ≥18 years admitted to the hospital with a core temperature below 35°C. We identified the cases from a literature review and from a retrospective case series of hypothermic patients admitted to the hospital between 1994 and 2016. Patients who experienced cardiac arrest, as well as those with potential confounders such as concomitant diseases or intoxications, were excluded. Relationships between core temperature and heart rate, systolic blood pressure, respiratory rate, and level of consciousness were explored via correlations and regression. Results: Of the 305 cases reviewed, 216 met the criteria for inclusion. The mean temperature was 29.7°C ± 4.2°C (range 19.3°C-34.9°C). The relationships between temperature and each of the four vital signs were generally linear and significantly positive, with Spearman correlations for respiratory rate, heart rate, systolic blood pressure, and Glasgow Coma Score (GCS) of 0.29 (p = 0.024), 0.44 (p < 0.001), 0.47 (p < 0.001), and 0.78 (p < 0.001), respectively. Based on linear regression, the mean decrease of a vital sign associated with a 1°C decrease of temperature was estimated to be 0.50 minute^-1 for respiratory rate, 2.54 minutes^-1 for heart rate, 4.36 mmHg for systolic blood pressure, and 0.88 for GCS. Conclusions: There is a significant positive correlation between core temperature and heart rate, systolic blood pressure, respiratory rate, and GCS. The relationship between vital signs and temperature is generally linear. This knowledge might help clinicians make appropriate decisions when determining whether the clinical condition of a patient should be attributed to hypothermia. This could enhance clinical care and help to guide future research.

Outcomes of patients suffering unwitnessed hypothermic cardiac arrest rewarmed with extracorporeal life support: A systematic review

Prolonged cardiac arrest (CA) may lead to neurologic deficit in survivors. Good outcome is especially rare when CA was unwitnessed. However, accidental hypothermia is a very specific cause of CA. Our goal was to describe the outcomes of patients who suffered from unwitnessed hypothermic cardiac arrest (UHCA) supported with Extracorporeal Life Support (ECLS). We included consecutive patients' cohorts identified by systematic literature review concerning patients suffering from UHCA and rewarmed with ECLS. Patients were divided into four subgroups regarding the mechanism of cooling, namely: air exposure; immersion; submersion; and avalanche. A statistical analysis was performed in order to identify the clinical parameters associated with good outcome (survival and absence of neurologic impairment). A total of 221 patients were included into the study. The overall survival rate was 27%. Most of the survivors (83%), had no neurologic deficit. Asystole was the presenting CA rhythm in 48% survivors, of which 79% survived with good neurologic outcome. Variables associated with survival included the following: female gender (P < .001); low core temperature (P = .005); non-asphyxia-related mechanism of cooling (P < .001); pulseless electrical activity as an initial rhythm (P < .001); high blood pH (P < .001); low lactate levels (P = .003); low serum potassium concentration (P < .001); and short resuscitation duration (P = .004). Severely hypothermic patients with unwitnessed CA may survive with good neurologic outcome, including those presenting as asystole. The initial blood pH, potassium, and lactate concentration may help predict outcome in hypothermic CA.

Prehospital Use of Ketamine in Mountain Rescue: A Survey of Emergency Physicians of a Single-Center Alpine Helicopter-Based Emergency Service

INTRODUCTION

Although ketamine use in emergency medicine is widespread, studies investigating prehospital use are scarce. Our goal was to assess the self-reported modalities of ketamine use, knowledge of contraindications, and occurrence of adverse events associated with its use by physicians through a prospective online survey.

METHODS

The survey was administered to physicians working for Air-Glaciers, a Swiss alpine helicopter-based emergency service, and was available between September 24 and November 23, 2018. We enrolled 39 participants (participation rate of 87%) in our study and collected data regarding their characteristics, methods of ketamine use, knowledge of contraindications, and encountered side effects linked to the administration of ketamine. We also included a clinical scenario to investigate an analgesic strategy.

RESULTS

Ketamine was considered safe and judged irreplaceable by most physicians. The main reason for ketamine use was acute analgesia during painful procedures, such as manipulation of femur fractures. The doses of ketamine administered with or without fentanyl ranged from 0.2 to 0.7 mg·kg^-1 intravenously. Most physicians reported using fentanyl and midazolam along with ketamine. The median dose of midazolam was 2 (interquartile range 1-2) mg for a 70-kg adult. Monitoring and oxygen administration were used infrequently. Hallucinations were the most common adverse events. Knowledge of ketamine contraindications was poor.

CONCLUSIONS

Ketamine use was reported by mountain rescue physicians to be safe and useful for acute analgesia. Most physicians use fentanyl and midazolam along with ketamine. Adverse neuropsychiatric events were rare. Knowledge regarding contraindications to the administration of ketamine should be improved.

Prehospital management of burns requiring specialized burn centre evaluation: a single physician-based emergency medical service experience

BACKGROUND

Emergency medical services regularly encounter severe burns. As standards of care are relatively well-established regarding their hospital management, prehospital care is comparatively poorly defined. The aim of this study was to describe burned patients taken care of by our physician-staffed emergency medical service (PEMS).

METHODS

All patients directly transported by our PEMS to our burn centre between January 2008 and December 2017 were retrospectively enrolled. We specifically addressed three "burn-related" variables: prehospital and hospital burn size estimations, type and volume of infusion and pain assessment and management. We divided patients into two groups for comparison: TBSA < 20% and ≥ 20%. We a priori defined clinically acceptable limits of agreement in the small and large burn group to be ±5% and ± 10%, respectively.

RESULTS

We included 86 patients whose median age was 26 years (IQR 12-51). The median prehospital TBSA was 10% (IQR 6-25). The difference between the prehospital and hospital TBSA estimations was outside the limits of agreement at 6.2%. The limits of agreement found in the small and large burn groups were - 5.3, 4.4 and - 10.1, 11, respectively. Crystalloid infusion was reported at a median volume of 0.8 ml/kg/TBSA (IQR 0.3-1.4) during the prehospital phase, which extrapolated over the first 8 h would equal to a median volume of 10.5 ml/kg/TBSA. The median verbal numeric rating scale on scene was 6 (IQR 3-8) and 3 (IQR 2-5) at the hospital (p < 0.001). Systemic analgesia was provided to 61 (71%) patients, predominantly with fentanyl (n = 59; 69%), followed by ketamine (n = 7; 8.1%). The median doses of fentanyl and ketamine were 1.7 mcg/kg (IQR 1-2.6) and 2.1 mg/kg (IQR 0.3-3.2), respectively.

CONCLUSIONS

We found good agreement in burn size estimations. The quantity of crystalloid infused was higher than the recommended amount, suggesting a potential risk for fluid overload. Most patients benefited from a correct systemic analgesia. These results emphasized the need for dedicated guidelines and decision support aids for the prehospital management of burned patients.

[Emergency department : COVID-19 crisis and organizational aspects]

Emergency departments are on the front line in the management of COVID-19 cases, from screening to the initial management of the most severe cases. The clinical presentation of COVID-19 range from non-specific symptoms to adult acute respiratory distress syndrome (ARDS). Diagnosis is based on PCR from a nasopharyngeal swab and emergency treatment rely on oxygen therapy. Patient's orientation (home, hospitalization, admission in intensive care unit) is a central aspect of emergency management. The shift from a strategy of systematic recognition of potential cases to the one of epidemic mitigation required hospital emergency medicine services to implement crisis management measures, to guarantee admission and hospitalization capacity.