Lung function and oxygen saturation after participation in Norseman Xtreme Triathlon.

OBJECTIVES: To examine evidence of exercise-induced bronchoconstriction (EIB) defined as ≥10% reduction in forced expiratory volume in one second (FEV1 ) and exercise-induced arterial hypoxemia (EIAH) defined as ≥4% reduction in oxygen saturation (SpO2 ) from before to after participation in the Norseman Xtreme Triathlon. Secondarily, to assess whether changes in FEV1 and SpO2 are related to respiratory symptoms, training volume, and race time. METHODS: In this quasi-experimental non-controlled study, we included 63 triathletes (50♂/13♀) aged 40.3 (±9.0) years (mean ± SD). Fifty-seven (46♂/11♀) measured lung function and 54 (44♂/10♀) measured SpO2 before the race, 8-10 minutes after the race (post-test 1) and the day after the race (post-test 2). Respiratory symptoms and training volume were recorded with modified AQUA questionnaire. ANOVA for repeated measures was used to detect differences in lung function and SpO2 . Statistical significance was accepted at 0.05 level. RESULTS: Twenty-six participants (46%) presented with EIB at post-test 1 and 16 (28%) at post-test 2. Lung function variables were significantly reduced from baseline to post-test 1 and 2. Thirty-five participants (65%) showed evidence of mild to moderate EIAH. No significant correlations were observed except a weak correlation between maximal reduction in FEV1 and respiratory symptoms (r = 0.35, P = .016). CONCLUSION: Our results demonstrated that 46% of the participants presented with EIB and 65% showed evidence of EIAH after the Norseman Xtreme Triathlon. Changes in FEV1 and SpO2 were not correlated to weekly training hours or race time. We observed a weak correlation between maximal reduction in FEV1 and respiratory symptoms.

Assessing Firefighters' Tourniquet Skill Attainment and Retention: A Controlled Simulation-Based Experiment.

BACKGROUND: The aim of this study was to train and assess firefighters' skill attainment in the use of tourniquets, and to assess their skill retention after 3 mo. The purpose is to show if firefighters can successfully apply a tourniquet after a short course based on the Norwegian national recommendation for civil prehospital tourniquet use. METHODS: This is a prospective experimental study. The study population were firefighters, and the inclusion criterion was any on-duty firefighter. The first phase consisted of baseline precourse testing (T1), a 45-min course, followed by immediate retesting (T2). The second phase consisted of retesting of skill retention after 3 mo (T3). RESULTS: A total of 109 participants at T1, 105 at T2, and 62 participants at T3. The firefighters achieved a higher proportion of successful tourniquet applications at T2 (91.4%; 96 of 105) as well as T3 (87.1%; 54 of 62) compared with 50.5% at T1 (55 of 109) (P = 0.009). Mean application time was 59.6 s (55.1-64.2) in T1, 34.9 s (33.3-36.6) in T2 and 37.7 s (33.9-41.4) in T3. CONCLUSION: A sample of firefighters can successfully apply a tourniquet after a 45-min course based on the 2019 Norwegian recommendation for civil prehospital tourniquet use. Skill retention after 3 mo was satisfactory for both successful application and application time.

3D-Printed Tourniquets Used at the Battlefront in Ukraine: A Pilot Study.

BACKGROUND: The war in Ukraine urged a need for prompt deliv- erance and resupply of tourniquets to the front. Producing tour- niquets near the battlefront was a feasible option with respect to resupply and cost. METHODS: A locally produced 3D-printed tourniquet (Ukrainian model) from the "Tech Against Tanks" charity was tested against commercially available and Committee of Tactical Combat Casualty Care (CoTCCC)- recommended tourniquets (C-A-T™ and SOF™TT-W). We tested how well the tourniquets could hold pressure for up to 2 hours. RESULTS: A Kruskal-Wallis test revealed significant differences between the groups (p<.05). Post-hoc testing revealed a signif- icant difference between the C-A-T and the Ukrainian tourni- quet (p=.004). A similar significance was not found between the SOF™TT-W Wide and the Ukrainian model (p=.08). Dis- cussion: The Ukrainian model can hold pressure as well as the commercially available tourniquets. There is much value if this can be produced close to the battlefield. Factors including lo- gistics, cost, and self-sufficiency are important during wartime. CONCLUSION: We found that our sample of 3D-printed tourni- quets, currently used in the war in Ukraine, could maintain pressure as well as the commercially available tourniquets. In- deed, our tests demonstrated that it could maintain a signifi- cantly higher pressure.

Altered Sympathoadrenal Activity Following Cold-Water Diving.

INTRODUCTION: Little data exist on the effect of extremely cold-water diving on thermo-metabolic hormone secretion. Moreover, the impact of repetitive dives on the stress response is unknown. The purpose of this study was to determine the effects of two daily bouts of cold-water diving on the hormonal and metabolic profile of elite military personnel and to measure the stress response. METHODS: Healthy, male, Norwegian Special Forces operators (n = 5) volunteered for this study. Physiological and hormone data were analyzed prior to and following twice-daily Arctic dives (3.3°C). RESULTS: Core temperature was maintained (p > .05), whereas skin temperature was significantly reduced over the course of each dive (p < .01). Pairwise comparisons revealed adrenocorticotropic hormone (ACTH) and cortisol concentration significantly decreased across both dives and days (p < .001). Adrenaline and noradrenaline significantly increased across both time and day (p < .001). Leptin, testosterone, and IGF-1 significantly decreased over time but recovered between days. CONCLUSION: The main findings of this effort are that there is a rapid sympathetic-adreno-medullary (SAM/SNS) response to cold-water diving and a suppression of the hypothalamic-pituitary-adrenal (HPA) axis and hormones related to repair and recovery. While the sample size was too small to determine the role of SAM/SNS, HPA, and thyroid hormone effect on thermoregulation, it addresses a gap in our understanding of physiological adaptions that occurs in extreme environments.

Norwegian Emergency Medicine Systems' Training and Equipment for Penetrating Injuries: A National Survey-Based Study.

OBJECTIVE: Recent terror attacks led the Norwegian government to develop a procedure for emergency and law enforcement services cooperation during Active Violent Incidents (AVI, abbreviated PLIVO in Norwegian). To address further national initiatives to improve preparedness for mass casualty events and penetrating injuries among emergency medical services (EMS) in Norway, training and equipment status were mapped. METHODS: All EMS regions in Norway were invited to participate in an electronic nation-wide survey about practical medical training in PLIVO scenario training and specific training in hemorrhage control and penetrating injuries. RESULTS: Ninety percent (842/938) had attended at least 1 PLIVO training scenario. Of these, 76% (642/938) reported only evacuation training during the exercise, while only 20% (168/938) had practiced hemorrhage control. Eighty-one percent (760/938) respondents reported that they were equipped with tourniquets and 91% (853/938) were equipped with gauze to pack wounds. However, only 52% (487/938) and 48% (450/938) reported practical training in tourniquet application and wound packing, respectively, while 30% (280/938) reported that they had no training or only theoretical education in tourniquet application. Supervised practical training on penetrating thoracic injuries was reported by <20%, and <50% reported practical training in needle decompression of a tension pneumothorax. CONCLUSIONS: Enhanced focus on training in hemorrhage control and penetrating injuries is needed. This supports the recent decision from the Norwegian government to strengthen the training for EMS in AVI (PLIVO) exercises, by focusing on medical procedures in addition to evacuation training. Although the estimated response rate is 17%, we believe the large number of respondents still make the results valuable.

Abstracts from The Cold Weather Operations Conference 2021.

A common effort for both military and civil healthcare is to achieve knowledge-based health care in cold weather injuries and fatal accidents in harsh arctic environment. The Cold Weather Operations Conference in November 2021, having more than 300 participants from 20 countries, was addressing the prevention and treatment of injuries and trauma care in cold weather conditions and the challenges for military prehospital casualty care. The intention of the programme was to stimulate further research and systematic knowledge-based clinical work. The abstracts from the conference present cold weather research and clinical experience relevant for readers of the International Journal of Circumpolar Health.

Impact of a 10,000-m Cold-Water Swim on Norwegian Naval Special Forces Recruits.

BACKGROUND: Special Operation Forces (SOF) operate regularly in extreme environmental conditions that may affect tactical and physical performance. The main aims of the present study were to elucidate the impact of a long cold-water swim on SOF recruits' dexterity, performance, and reaction time. MATERIAL AND METHODS: Eleven recruits from Norwegian Naval Special Operation Command (NORNAVSOC) that were participating in a 10,000-m open water swim with a dry suit in 5°C cold water volunteered to participate in this study. The exercise was part of their training. Grip strength, lower body power, and dexterity were measured before, immediately after, and 24 hours after the swim. In addition, core and skin temperatures were measured continuously during the swim and until 45 minutes after the swim. RESULTS: After the swim, moderate to large reductions in core temperature, lower body power, and reaction time were observed. Moreover, very large to extremely large reductions in skin temperature, grip strength, and dexterity were also observed. CONCLUSION: These results demonstrate that exposure to a 10,000-m swim in 5°C water using standard equipment led to a significant drop in the recruits' temperature and performance. These findings could have a meaningful impact on the planning of training, operations, and gear used for SOF.

Does Cold-Water Endurance Swimming Affect Pulmonary Function in Healthy Adults?

The acute effects of cold-water endurance swimming on the respiratory system have received little attention. We investigated pulmonary responses to cold-water endurance swimming in healthy recreational triathletes. Pulmonary function, alveolar diffusing capacity (DLCO), fractional exhaled nitric oxide (FENO) and arterial oxygen saturation by pulse oximetry (SpO2) were assessed in 19 healthy adults one hour before and 2.5 h after a cold-water (mean ± SD, 10 ± 0.9 °C) swim trial (62 ± 27 min). In addition, 12 out of the 19 participants measured pulmonary function, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) 3, 10, 20 and 45 min post-swim by maximal expiratory flow volume loops and DLCO by the single breath technique. FVC and FEV1 were significantly reduced 3 min post-swim (p = 0.02) (p = 0.04), respectively, and five of 12 participants (42%) experienced exercise-induced bronchoconstriction (EIB), defined as a ≥ 10% drop in FEV1. No significant changes were observed in pulmonary function 2.5 h post-swim. However, mean FENO and DLCO were significantly reduced by 7.1% and 8.1% (p = 0.01) and (p < 0.001), respectively, 2.5 h post-swim, accompanied by a 2.5% drop (p < 0.001) in SpO2. The absolute change in DLCO correlated significantly with the absolute decline in core temperature (r = 0.52; p = 0.02). Conclusion: Cold-water endurance swimming may affect the lungs in healthy recreational triathletes lasting up to 2.5 h post-swim. Some individuals appear to be more susceptible to pulmonary impairments than others, although these mechanisms need to be studied further.

Transient Reduction of FMD-Response and L-Arginine Accompanied by Increased Levels of E-Selectin, VCAM, and ICAM after Prolonged Strenuous Exercise.

We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4-15.3) h. FMD was significantly reduced to 3.1 (2.1-5.0)% dilatation compared to 8.7 (8.2-9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.

Reduced L-Arginine and L-Arginine-ADMA-Ratio, and Increased SDMA after Norseman Xtreme Triathlon.

Endothelial vasodilatory function is dependent on the NO synthesis from L-arginine by endothelial NO-synthetase (eNOS). eNOS can be inhibited by asymmetric dimethylarginine (ADMA) by competitive inhibition on the binding site, and symmetric dimethylarginine (SDMA) can reduce the L-arginine availability intracellularly through competing for transport over the cellular membrane. To study the NO synthesis after prolonged exercise, we assessed circulatory L-arginine, the L-arginine/ADMA ratio, and SDMA before, after, and on the day after the Norseman Xtreme triathlon, an Ironman distance triathlon. We found significantly reduced levels of L-arginine and the L-arginine/ADMA ratio and increased levels of SDMA after the race (all p < 0.05). L-arginine rose toward baseline levels the day after the race, but ADMA increased beyond baseline levels, and SDMA remained above baseline the day after the race. The reduced levels of L-arginine and the L-arginine/ADMA ratio, and increased SDMA, after the race indicate a state of reduced capability of NO production. Increased levels of ADMA and SDMA, and reduced L-arginine/ADMA ratio, as seen the day after the race, are known risk markers of atherosclerosis and warrant further studies.

Core Temperature during Cold-Water Triathlon Swimming.

Triathlon and other endurance races have grown in popularity. Although participants are generally fit and presumably healthy, there is measurable morbidity and mortality associated with participation. In triathlon, most deaths occur during the swim leg, and more insight into risk factors, such as hypothermia, is warranted. In this study, we measured the core temperature of 51 participants who ingested temperature sensor capsules before the swim leg of a full-distance triathlon. The water temperature was 14.4-16.4 °C, and the subjects wore wetsuits. One subject with a low body mass index and a long swim time experienced hypothermia (<35 °C). Among the remaining subjects, we found no association between core temperature and swim time, body mass index, or sex. To conclude, the present study indicates that during the swim leg of a full-distance triathlon in water temperatures ≈ 15-16 °C, subjects with a low body mass index and long swim times may be at risk of hypothermia even when wearing wetsuits.

Effects of Krill Oil and Race Distance on Serum Choline and Choline Metabolites in Triathletes: A Field Study.

Choline is an essential nutrient that has been implicated in athletic performance due to its role in maintaining normal muscle function. The concentration of free choline in serum may decrease during long-distance high-intensity exercise, yet few nutritional strategies to counteract this potentially performance-depleting loss in choline have been investigated outside the laboratory. This exploratory field study was performed to investigate if pre-race supplementation with phosphatidylcholine from krill oil can counteract the expected drop in choline and some of its metabolites during triathlon competitions. Forty-seven triathletes, 12 females and 35 males ranging in age from 25 to 61 years, were recruited from participants in the Ironman-distance Norseman Xtreme triathlon and the Sprint/Olympic-distance Oslo Triathlon. Twenty-four athletes were randomly allocated to the krill oil group, receiving 4 g of SuperbaBoost™ krill oil daily for 5 weeks prior to the race, and 23 athletes were randomly allocated to the placebo group, receiving 4 g of mixed vegetable oil daily. Blood samples were obtained before the race, immediately after completion of the race, and the day after the race for analysis of choline and its metabolites. The results showed that serum choline concentrations significantly decreased from pre-race to race finish in all races, with a more pronounced decrease observed in the Ironman-distance Norseman Xtreme triathlon (34% decrease) relative to the Sprint/Olympic-distance Oslo Triathlon (15% decrease). A reduction in betaine was also observed, while dimethylglycine (DMG) concentrations remained stable across all time points. Significantly higher concentrations of choline (9.4% on average) and DMG (21.4% on average) were observed in the krill oil compared to the placebo group, and the krill oil group showed a significantly greater increase in serum choline following race completion. In conclusion, krill oil may help to prevent that circulating choline concentrations become limiting during endurance competitions.

Biochemical markers after the Norseman Extreme Triathlon.

Prolonged exercise is known to cause changes in common biomarkers. Occasionally, competition athletes need medical assistance and hospitalisation during prolonged exercise events. To aid clinicians treating patients and medical teams in such events we have studied common biomarkers after at The Norseman Xtreme Triathlon (Norseman), an Ironman distance triathlon with an accumulated climb of 5200 m, and an Olympic triathlon for comparison. Blood samples were collected before, immediately after, and the day following the Norseman Xtreme Triatlon (n = 98) and Oslo Olympic Triathlon (n = 15). Increased levels of clinical significance were seen at the finish line of the Norseman in white blood cells count (WBC) (14.2 [13.5-14.9] 109/L, p < 0.001), creatinine kinase (CK) (2450 [1620-3950] U/L, p < 0.001) and NT-proBNP (576 [331-856] ng/L, p < 0.001). The following day there were clinically significant changes in CRP (39 [27-56] mg/L, p < 0.001) and Aspartate Aminotransferase (AST) (142 [99-191] U/L, p < 0.001). In comparison, after the Olympic triathlon distance, there were statistically significant, but less clinically important, changes in WBC (7.8 [6.7-9.6] 109/L, p < 0.001), CK (303 [182-393] U/L, p < 0.001) and NT-proBNP (77 [49-88] ng/L, p < 0.01) immediately after the race, and in CRP (2 [1-3] mg/L, p < 0.001) and AST (31 [26-41] U/L, p < 0.01) the following day. Subclinical changes were also observed in Hemoglobin, Thrombocytes, K+, Ca2+, Mg2+, Creatinine, Alanine Aminotransferase and Thyroxine after the Norseman. In conclusion, there were significant changes in biomarkers used in a clinical setting after the Norseman. Of largest clinical importance were clinically significant increased WBC, CRP, AST, CK and NT-proBNP after the Norseman. This is important to be aware of when athletes engaging in prolonged exercise events receive medical assistance or are hospitalised.

Core Temperature in Triathletes during Swimming with Wetsuit in 10 °C Cold Water.

Low water temperature (<15 °C) has been faced by many organizers of triathlons and swim-runs in the northern part of Europe during recent years. More knowledge about how cold water affects athletes swimming in wetsuits in cold water is warranted. The aim of the present study was therefore to investigate the physiological response when swimming a full Ironman distance (3800 m) in a wetsuit in 10 °C water. Twenty triathletes, 37.6 ± 9 years (12 males and 8 females) were recruited to perform open water swimming in 10 °C seawater; while rectal temperature (Tre) and skin temperature (Tskin) were recorded. The results showed that for all participants, Tre was maintained for the first 10-15 min of the swim; and no participants dropped more than 2 °C in Tre during the first 30 min of swimming in 10 °C water. However; according to extrapolations of the results, during a swim time above 135 min; 47% (8/17) of the participants in the present study would fall more than 2 °C in Tre during the swim. The results show that the temperature response to swimming in a wetsuit in 10 °C water is highly individual. However, no participant in the present study dropped more than 2 °C in Tre during the first 30 min of the swim in 10 °C water.

Relationship between level of CPR training, self-reported skills, and actual manikin test performance-an observational study.

BACKGROUND: Quality of bystander cardiopulmonary resuscitation (CPR) skills may influence out of hospital cardiac arrest (OHCA) outcomes. We analyzed how the level of CPR training related to indicators of good CPR quality and also the relationship between self-reported skills and actual CPR performance. METHODS: Two hundred thirty-seven persons trained in standardized BLS curricula were divided into three groups according to the level of training: group I (40 h basic first aid training), group II, and group III (96 h advanced first aid, group III had also some limited additional life support training courses). We recorded the participants' real-life CPR experience and self-reported CPR skills, and then assessed selected CPR quality indicators on a manikin. The data were analyzed with multivariate logistic regression. Differences between groups were analyzed with ANOVA/MANOVA. RESULTS: Out of 237 participants, 125 had basic training (group I), 84 reported advanced training (group II), and 28 advanced training plus additional courses (group III). Group II and III had shorter start-up time, better compression depth and hand positioning, higher fraction of effective rescue ventilations, shorter hands-off time, and thus a higher chest compression fraction. Chest compression rate did not differ between groups. The participants in group I assessed their own skills and preparedness significantly lower than groups II and III both before and after the test. In addition, group III reported higher confidence in examining the critically ill patient and preparedness in doing CPR before the manikin test than both groups I and II. However, the observed differences between groups II and III in self-reported skills and preparedness were not statistically significant after the test. CONCLUSION: As expected, higher levels of BLS training correlated with better CPR quality. However, this study showed that ventilations and hands-on time were the components of CPR that were most affected by the level of training. Self-assessments of CPR ability correlated well to actual test performance and may have a role in probing CPR skills in students. The results may be important for BLS instructors and program developers.

Late-Presenting Swimming-Induced Pulmonary Edema: A Case Report Series from the Norseman Xtreme Triathlon.

Swimming-induced pulmonary edema (SIPE) may develop during strenuous physical exertion in water. This case series reports on three cases of suspected late-presenting SIPE during the Norseman Xtreme Triathlon. A 30-year-old male professional (PRO) triathlete, a 40-year-old female AGE GROUP triathlete and a 34-year-old male AGE GROUP triathlete presented with shortness of breath, chest tightness and coughing up pink sputum during the last part of the bike phase. All three athletes reported an improvement in breathing during the first major uphill of the bike phase and increasing symptoms during the downhill. The PRO athlete had a thoracic computed tomography, and the scan showed bilateral ground glass opacity in the peripheral lungs. The male AGE GROUP athlete had a normal chest x-ray. Both athletes were admitted for further observation and discharged from hospital the following day, with complete regression of symptoms. The female athlete recovered quickly following pre-hospital oxygen treatment. Non-cardiogenic pulmonary edema associated with endurance sports is rare but potentially very dangerous. Knowledge and awareness of possible risk factors and symptoms are essential, and the results presented in this report emphasize the importance of being aware of the possible delayed development of symptoms. To determine the presence of pulmonary edema elicited by strenuous exercise, equipment for measuring oxygen saturation should be available for the medical staff on site.