Page 45 - JSOM Fall 2021

Outcome this has led to the development of a number of novel meth-
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Once assessment and initial care were completed, the patient ods to enhance performance in these environments. Garment
was relocated to a safe location away from the overhanging technology for physically demanding work has evolved pre-
tree canopy in which winch extraction to the aircraft was per- dominantly through military research. Modern fabrics allow
formed. The patient was then transported to hospital. After for more effective heat dissipation and may include active
completion of this task, the aircrew and ICFP were immediately cooling elements, thus reducing core temperature, heat stress,
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tasked to two further back-to-back non–physically demanding and physiological demand. Novel cooling strategies such as
cases; however, this did limit opportunity for recovery. arm immersion in cold water, ice vests, and ingestion of energy
drink ice slurries demonstrate value for temperature reduction
in the post exertion recovery phase. 18,20–22 Some of these strat-
Discussion
egies may be particularly useful in HEMS SAR operations, in
This report details data collection methods in rescue person- which personnel may be required to undertake multiple phys-
nel and demonstrates the level of physiological strain that ical demanding tasks during a shift.
may be encountered during HEMS SAR operations in remote
wilderness and extreme heat. With increasing participation Load carriage during physically demanding tasks is known to
in outdoor recreational pursuits and the increased frequency modify metabolic demand and increase physiological strain,
of extreme weather events, it is essential that special opera- yet it is an essential component of specialist team response.
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tions teams performing physically demanding tasks adapt and Lightweight technical rescue and medical equipment is an
evolve. This will ensure personnel are appropriately selected, ever-evolving area with a wide range of proprietary offerings.
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trained, and equipped to respond in these conditions. Organizations requiring significant load carriage in physically
demanding specialist response roles should ensure equip-
The physical status of this ICFP was comparable to that seen ment is restricted to the most essential items. It should also
in other studies investigating SAR professionals and special- be adaptable to extreme environments and high temperatures
ist paramedics. 13,14 Some authors have proposed a minimum to minimize physiological strain. Organizations deploying
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Vo 2peak of 40–45 mL/kg/min for specialist rescue roles (e.g., specialist rescue personnel to remote and hostile environments
mines rescue personnel and fire fighters), and the ICFP in this should consider long-term monitoring of physiological work-
case exceeded this threshold. 15,16 Possessing well-developed load during rescues. These organizations should also initiate
aerobic capacity, high physical activity levels, and good over- continuous quality improvement programs to review PES,
all health may be important factors when designing PES and garments, equipment, employee readiness, and adaptability to
ongoing strength and conditioning programs for physically- deliver services in an ever-changing response environment.
demanding occupations. However, the concept of a minimum
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Vo 2peak for selection to this ICFP role requires investigation in Limitations
formal studies that examine a range of physiological and per-
formance demands of winch rescue. We acknowledge that data such as HR, RPE, and MAWT from
a single participant completing a physically demanding task
The ICFP was required to sustain 81% of maximum HR (an may not reflect the physiological responses in other ICFPs
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approximate Vo of 44.8 mL/kg/min, based on Vo 2peak ) for just completing a similar task, and studies in a representative sam-
over 10 minutes at an RPE 6-20 of 19 and RHR of 77.5% in ple of the occupational group are required. Additionally, we
37.1°C. This high physiological strain must be placed in the acknowledge that the wearable technology used in this study
context of the fact that ICFPs must be able to deliver clini- may have variable accuracy and reliability, whilst appreciating
cal care once they reach the patient. A study in male Soldiers the usefulness of such devices to capture physiological data in
demonstrated that nonacclimated personnel suffered greater the environments described. 25
cognitive impairment when exposed to exertional heat stress
when compared to those who were acclimatized to heat. Cal-
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culated MAWT for this task was 37.7 minutes, and although Conclusion
this individual task was less than one-third the duration of This report highlights that HEMS SAR operations may require
MAWT, it is possible that further similar or more demanding specialist personnel to be exposed to high physiological de-
tasks may have to be completed by the ICFP during the same mands in remote wilderness and extreme climatic conditions.
shift. Additionally, repeated incidences of high physiological Assessment of physiological parameters during HEMS SAR
workload (especially in hot climates) should factor into work- operations is viable, but future work to develop PES should
force and response planning, PES development, and determi- include assessment of additional elements. One example is
nation of appropriate shift duration. Of note, the method we oxygen consumption during task simulations as a method of
used to calculate MAWT is based on heart rate (RHR), and enhancing scientific validity. Coupled with the progression of
although it is well established that there is good agreement climate change and increasing participation in outdoor pur-
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between RHR and relative Vo , direct assessment of oxygen suits, organizations must ensure that staff are selected to the
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consumption is considered the most accurate method. For- role via scientifically valid and reliable PES. Specialist rescue
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mal physiological assessment of this population should mea- organizations should initiate continuous quality improvement
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sure relative Vo to determine MAWT. programs to review and adapt selection processes, physical
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readiness programs, and specialist equipment to suit the dy-
To limit physiological strain and enable performance of namic operational response environment.
postexertion cognitive tasks (such as delivery of advanced clin-
ical care), rescue services should pursue strategies to minimize Acknowledgments
physiological stress in hot environments. Increased rates of The authors thank Ambulance Victoria and the ICFP for their
exertional heat illness are reported in the military setting, and support in making the data for this report available.
Physiological Response in Paramedic Helicopter Winch Rescue | 43