Nonfreezing Cold Injuries Among Long-Distance Polar Rowers

Can iloprost be used for treatment of cold weather injury at the point of wounding in a forward operating environment? A literature review

INTRODUCTION

Cold Weather Injury (CWI) represents a spectrum of pathology, the two main divisions being Freezing Cold Injury (FCI) and Non-Freezing Cold Injury (NFCI). Both are disabling conditions associated with microvascular and nerve injury often treated hours after initial insult when presenting to a healthcarestablishment. Given that iloprost is used for the treatment of FCI, could it be used in a forward operating environment to mitigate treatment delay? Is there a role for its use in the forward treatment of NFCI? This review sought to evaluate the strength of evidence for the potential use of iloprost in a forward operating environment.

METHODS

Literature searches were undertaken using the following question for both FCI and NFCI: in [patients with FCI/NFCI] does [the use of iloprost] compared to [standard care] reduce the incidence of [long-term complications]. Medline, CINAHL and EMBASE databases were searched using the above question and relevant alternative terminology. Abstracts were reviewed before full articles were requested.

RESULTS

The FCI search yielded 17 articles that were found to refer to the use of iloprost and FCI. Of the 17, one referred to pre-hospital treatment of frostbite at K2 base camp; however, this was utilising tPA. No articles referred to pre-hospital use in either FCI or NFCI.

DISCUSSION

Although evidence exists to support the use of iloprost in the treatment of FCI, its use to date has been in hospital. A common theme is delayed treatment due to the challenges of evacuating casualties from a remote location. There may be a role for iloprost in the treatment of FCI; however, further study is required to better understand the risk of its use.

The peripheral vascular responses in non-freezing cold injury and matched controls

NEW FINDINGS

What is the central question of this study? Does non-freezing cold injury (NFCI) alter normal peripheral vascular function? What is the main finding and its importance? Individuals with NFCI were more cold sensitive (rewarmed more slowly and felt more discomfort) than controls. Vascular tests indicated that extremity endothelial function was preserved with NFCI and that sympathetic vasoconstrictor response might be reduced. The pathophysiology underpinning the cold sensitivity associated with NFCI thus remains to be identified.

ABSTRACT

The impact of non-freezing cold injury (NFCI) on peripheral vascular function was investigated. Individuals with NFCI (NFCI group) and closely matched controls with either similar (COLD group) or limited (CON group) previous cold exposure were compared (n = 16). Peripheral cutaneous vascular responses to deep inspiration (DI), occlusion (PORH), local cutaneous heating (LH) and iontophoresis of acetylcholine and sodium nitroprusside were investigated. The responses to a cold sensitivity test (CST) involving immersion of a foot in 15°C water for 2 min followed by spontaneous rewarming, and a foot cooling protocol (footplate cooled from 34°C to 15°C), were also examined. The vasoconstrictor response to DI was lower in NFCI compared to CON (toe: 73 (28)% vs. 91 (17)%; P = 0.003). The responses to PORH, LH and iontophoresis were not reduced compared to either COLD or CON. During the CST, toe skin temperature rewarmed more slowly in NFCI than COLD or CON (10 min: 27.4 (2.3)°C vs. 30.7 (3.7)°C and 31.7 (3.9)°C, P < 0.05, respectively); however, no differences were observed during the footplate cooling. NFCI were more cold-intolerant (P < 0.0001) and reported colder and more uncomfortable feet during the CST and footplate cooling than COLD and CON (P < 0.05). NFCI showed a decreased sensitivity to sympathetic vasoconstrictor activation than CON and greater cold sensitivity (CST) compared to COLD and CON. None of the other vascular function tests indicated endothelial dysfunction. However, NFCI perceived their extremities to be colder and more uncomfortable/painful than the controls.

Plasma biomarkers of endothelial function, inflammation and oxidative stress in individuals with non-freezing cold injury

NEW FINDINGS

What is the central question of this study? Are biomarkers of endothelial function, oxidative stress and inflammation altered by non-freezing cold injury (NFCI)? What is the main finding and its importance? Baseline plasma [interleukin-10] and [syndecan-1] were elevated in individuals with NFCI and cold-exposed control participants. Increased [endothelin-1] following thermal challenges might explain, in part, the increased pain/discomfort experienced with NFCI. Mild to moderate chronic NFCI does not appear to be associated with either oxidative stress or a pro-inflammatory state. Baseline [interleukin-10] and [syndecan-1] and post-heating [endothelin-1] are the most promising candidates for diagnosis of NFCI.

ABSTRACT

Plasma biomarkers of inflammation, oxidative stress, endothelial function and damage were examined in 16 individuals with chronic NFCI (NFCI) and matched control participants with (COLD, n = 17) or without (CON, n = 14) previous cold exposure. Venous blood samples were collected at baseline to assess plasma biomarkers of endothelial function (nitrate, nitrite and endothelin-1), inflammation [interleukin-6 (IL-6), interleukin-10 (IL-10), tumour necrosis factor alpha and E-selectin], oxidative stress [protein carbonyl, 4-hydroxy-2-nonenal (4-HNE), superoxide dismutase and nitrotyrosine) and endothelial damage [von Willebrand factor, syndecan-1 and tissue type plasminogen activator (TTPA)]. Immediately after whole-body heating and separately, foot cooling, blood samples were taken for measurement of plasma [nitrate], [nitrite], [endothelin-1], [IL-6], [4-HNE] and [TTPA]. At baseline, [IL-10] and [syndecan-1] were increased in NFCI (P < 0.001 and P = 0.015, respectively) and COLD (P = 0.033 and P = 0.030, respectively) compared with CON participants. The [4-HNE] was elevated in CON compared with both NFCI (P = 0.002) and COLD (P < 0.001). [Endothelin-1] was elevated in NFCI compared with COLD (P < 0.001) post-heating. The [4-HNE] was lower in NFCI compared with CON post-heating (P = 0.032) and lower than both COLD (P = 0.02) and CON (P = 0.015) post-cooling. No between-group differences were seen for the other biomarkers. Mild to moderate chronic NFCI does not appear to be associated with a pro-inflammatory state or oxidative stress. Baseline [IL-10] and [syndecan-1] and post-heating [endothelin-1] are the most promising candidates for diagnosing NFCI, but it is likely that a combination of tests will be required.

Common health issues and advised treatments reported in an ultraendurance ocean rowing race

Objectives

Ocean rowing is an extreme ultraendurance sport where individuals row unsupported across an ocean. This can mean months at sea in unpredictable and inhospitable conditions. The extreme physical and mental demands associated mean medical issues are common yet under researched, impacting the medical assistance provided.

Methods

The Talisker Whisky Atlantic Challenge provides a framework with safety protocols to create safer environments for athletes to attempt transatlantic crossings. Race logs, which record communication between rowers and safety teams, were anonymised and examined to create cumulative totals of medical issues requiring help and an incident timeline.

Results

Duty officers were notified of 65 medical complaints, 32% (n=21) requiring race doctors. Dermatological conditions were most common, accounting for 32% of complaints (n=21) and affecting 24% of rowers. Pressure sores and infections represented 43% and 38% of dermatological complaints respectively. Musculoskeletal injuries equalled 18% (n=12) of complaints, affecting 20% of rowers. Most cases were reported in weeks one and three, with 37% (n=24) of issues and 90% (n=10) of seasickness cases in week one. Hygiene and antibiotics were frequently advised management options.

Conclusion

Conditions requiring race doctor input represent the most severe cases with the potential to deteriorate. Managing dermatological and musculoskeletal issues is vital throughout the race, while seasickness prophylaxis and education is essential in initial race stages. Infections are cause for concern, with gluteal pressure sores a potential route for secondary infections. Further research is required before evidence-based guidelines for management of health issues in ocean rowers can be introduced.

Common Health Issues Encountered by Ultraendurance Ocean Rowers

INTRODUCTION

Ocean rowing is an extreme ultraendurance sport in which athletes push themselves to their mental and physical limits while rowing across an ocean. Limited academic attention has meant health issues facing this population are poorly understood. This report provides a descriptive analysis of the injuries and illnesses encountered by ocean rowers at sea and suggests potential preventative measures.

METHODS

Retrospective self-reported data were collected from ocean rowers via an online 29-question survey, classified by medical system, and totaled to produce a report of the most frequently encountered symptoms.

RESULTS

Seventy-one ocean rowers, accounting for 86 ocean rowing attempts, completed the survey. Dermatologic symptoms formed 52% (n=169) of all reported issues, followed by musculoskeletal injuries (14%; n=45), mental health symptoms (11%; n=36), gastrointestinal symptoms (5%; n=16), and neurologic symptoms (2%). Gluteal pressure sores were the most common dermatologic symptoms (24%; n=40), hallucinations the most common mental health symptoms (69%; n=25), hand and finger issues the most reported musculoskeletal problems (36%; n=16); vomiting (38%) and headaches (50%) were the most common gastrointestinal and neurologic issues, respectively. Seasickness was reported in 42% of expeditions (n=33).

CONCLUSIONS

This report presents the physiological, mental, and medical challenges facing ocean rowers. Dermatologic and musculoskeletal issues were most common and varied greatly in severity. Over 90% of reported infections occurred as a dermatologic complaint, demonstrating the importance of preventative measures such as hygiene and wound care. Continued work with a larger population is required to further understand the physiological stress and medical complaints associated with transoceanic rowing.

ACSM Expert Consensus Statement: Injury Prevention and Exercise Performance during Cold-Weather Exercise

ABSTRACT

Cold injury can result from exercising at low temperatures and can impair exercise performance or cause lifelong debility or death. This consensus statement provides up-to-date information on the pathogenesis, nature, impacts, prevention, and treatment of the most common cold injuries.