Since 1997
Medical Concerns and the Ageing Diver
by Dr Lourens De Kock on August 24th, 2017

Two concerns burden the older diver: fitness for the intended activity and the likelihood of survival. Put otherwise, am I fit enough to continue with my passion without getting injured, or even dying?
Before we explore the concerns in more detail, it is important to define the concept of “ageing”. “Old” or “aged” cannot simply be defined in terms of a number of years (chronological age), due to the often observed, significant discrepancies between the health status of people with the same year of birth. Physiological age is therefore a much more realistic consideration in terms of establishing fitness for continued participation in scuba activities. At first, physiological age seems quite easily definable but there is a lot of subjectivity involved in the concept. To understand physiological (“apparent”) age, we need to consider
  • Physical fitness
  • Health status, including existing morbidities and possible associated co-morbidities
  • Mobility and strength (musculoskeletal system)
  • Cognitive function (primal and higher brain functioning)
Table 1 demonstrates that a holistic approach to the assessment of diving fitness should be sought at all times, particularly with older divers.

In the face of progressive deterioration of the ageing body, there is one factor that improves with age and that contributes significantly to prolonging diving ability: judgement. This concept is presented in simple terms in Figure 1 below.
PHYSICAL FITNESS

Physical fitness can be defined as the readiness or ability to perform tasks that require increased expenditure of energy. In diving, this would mean that the diver must be able to cope with conditions that require additional physical effort over and above his fitness levels required to participate in a regular, run-of-the-mill dive.

The following comments from an article by Dr Alfred Bove (Undersea and Hyperbaric Medicine, 2011) reflect on what fitness levels are appropriate for diving.

The demand for swimming ability for safe diving in most environments is not likely to exceed 4.5-6 m per minute for commercial divers and 1.2-1.5 m per minute for recreational divers. However, in situations where excessive current or distance is involved, demand could reach up to 30 m per minute.

Oxygen consumption (VO2) demands during usual contingencies can reach levels of 20ml/kg per minute, equivalent to 6-7 Metabolic Equivalents (METs). Maximal steady state that allows continuous exercise without excess ventilation and increasing blood lactate levels is a workload of about 50% of the VO2 maximum. This state can be sustained for 50-60 minutes. However, at a workload of 60-70% of the VO2 maximum, only 15-20 minutes of exertion can be maintained without significant fatigue. Therefore, a diver with an exercise capacity of 6-7 METs can expect to manage general diving conditions without concern for cardiovascular complications.

However, divers who want to minimise safety concerns related to challenging external and environmental conditions should have a minimum oxygen consumption capacity of at least 12-13 METs. If your exercise level is less than this requirement, it is advisable to dive in low-stress conditions (warm water, minimal currents and minimal surface action), as identified in Figure 2 overleaf.
Evidence of cardiovascular limitation under stressful diving conditions will manifest as an increased ventilation rate, with the sensation of shortness of breath while breathing through a mouthpiece/regulator. This situation can often induce panic; a state that leads to poor decision-making, mistakes and dire consequences. Panic should be avoided at all costs in the sub-aquatic environment.

Various assessments of diving fitness are available, and not all require expensive equipment and research laboratories. There is a very practical fitness test to consider, which can be done in your nearest training pool. The International Association of Rescue Diving Specialists (IARDS) uses a so-called “Watermanship Test” and this can be used to evaluate the level of fitness expected of rescue divers. You can find this test at the end of this article. Try the exercises and determine your overall fitness score.

I am of the opinion that the minimum level of fitness (12 points) should be sought and maintained throughout the lifespan of recreational divers. Of importance here is the sustained ability to function in the water. Fitness for other, land-based sporting disciplines might not contribute well enough to the required in-water fitness level. Fitness improvement and maintenance is of vital importance in the months before diving trips that include multiple dives per day and multi-day diving schedules.

Even the most conscientious fitness seeker will see his fitness levels wane with age, but with good judgement, diving can still be part of his life. Diving conditions vary widely; they need to be balanced with fitness levels to ensure a dive with an acceptable safety rating, as demonstrated in Figure 2 above.
HEALTH STATUS

Spivey Law Firm, a Florida-based firm, summarised the 2014 UHMS/DAN Fatalities Symposium on their website to emphasise the significant percentage of “litigation-able” conditions in the diving industry. They are as follows.

The four main factors which cause death in diving accidents are
1. Poor health – 20%
2. Equipment problems – 22%
3. Procedural issues – 26%
4. Environmental issues – 32%

These figures show that 80% of deaths in diving accidents are caused by non-health-related factors. However, we shall focus on the 20% that are related to health factors, as these are of particular concern with ageing divers. In his article Diving for Seniors, published online on Skin Diver, Dr Bove identifies the organ systems that are especially vulnerable in the ageing body. These are detailed overleaf.
Central nervous system

Ageing leads to a generalised slowing of reflexes, and a deterioration of fine muscle co-ordination, balance, hearing and vision. The adverse effects of this can be offset by carefully planning dives that occur in physically demanding circumstances. These ageing effects seldom have dire consequences during low-stress, recreational diving activities.

Lungs

Reduced oxygen transport capacity, increased CO2 retention under taxing physical conditions and increased stiffness of the lungs contribute to limitations. This is particularly noticeable when physical effort requirements are increased due to dangerous diving conditions or situations of stress and panic. 

Muscles and joints

With ageing comes changes in muscles and joints, translating to reductions in mobility and strength. This has a significant effect on exercise function and flexibility. The older diver often stops diving when it is too hard to do, no longer worth the effort, or simply not fun to mobilise in the water (get in and out of the water), and especially when donning and doffing thermal protective wear becomes difficult. These activities become uncomfortable and challenging with worsening pathology. Carrying and manipulation of heavy scuba gear can often be delegated to some degree before these activities also become untenable.

Cardiovascular and circulation system

This system is by far the most important to consider in the ageing diver. Older divers are at greater risk of fatal accidents and the most common cause of death is an acute cardiac event. All divers who have reached the age of 50 should have their cardiovascular risk factors reviewed by their doctor. CVS risk should be calculated and a stratification performed. A low-risk score (for instance <10% on the widely used Framingham Risk Score (FRS)) will generally indicate that the individual is not likely to have an acute coronary event while diving. FRS scores of 10-20 must prompt further risk stratification; a proper stress ECG on the Bruce protocol should be conducted. There are various other means of stratification and these can be discussed with your doctor. Individuals with known cardiovascular diseases who have successfully undergone revascularisation procedures may be allowed to dive in low-stress environments.

Due to the unique stressors experienced during diving (such as immersion response and thermal stress), the cardiovascular system takes huge strain. It must accommodate and recirculate the excessive blood volumes which are shunted to the thoracic region during immersion. Degradation of the natural pacemaker cells, increased rigidity of anatomical structures of the heart and imbalance of the autonomic nervous system make the heart increasingly susceptible to catastrophic failure. If physical and/or emotional stress (increased heart rate and volumes) are added to this scenario, failure will set in earlier and be more catastrophic.

Morbidities and Co-morbidities

Disease and the development of pathologies are part andparcel of ageing. These conditions are always to be treated and monitored according to first-world standards. Use of medications
compatible with diving needs to be considered on a case-by-case basis; choice of medication must be tailored to the individual as well as to the specific dive conditions. Co-operative engagement between diving operators, experienced diving instructors and knowledgeable medical personnel can often ensure safe diving experiences for carefully selected individuals, even with significant morbidity.

TIPS FOR THE AGEING DIVER

Diving fitness in the ageing diver should be practically assessed by using physiological age instead of chronological age. Periodic assessments of the organ systems most commonly affected in the ageing process should be scheduled with a medical professional.

Particular care should be taken to assess the cardiovascular system properly. It is significant to note that the pathology of this system is often asymptomatic. In this case, the chronological age of 50 years must be the definitive-action set point at which to start periodic screening.

Maintaining the best possible levels of physical fitness is of monumental importance. Specific watermanship training should be included in a fitness programme. The take-home message is
to get fit and stay fit. Always remember to breathe slowly, in and all the way out. Actively improve your judgement and start a periodic, medical-screening programme.
IARDS TEST FOR JUDGING FITNESS

International Association Of Rescue Diving Specialists Watermanship Testing
  • Score performance of each exercise from 5 (best) to 1 (worst)
    • Note “Incomplete” if exercise is not finished
    • Exercise 5 must be scored either as “Pass” or as “Incomplete
  • Minimum of 12 points to pass (20 total + “Pass” or “Incomplete” for object retrieval in 3 m of water)
  • Rest for no more than 15 minutes between tests
EXERCISE 1: 450 M SWIM (NO AIDS)
Under 10 minutes = 5 points
10-13 minutes = 4 points
13-16 minutes = 3 points
16-19 minutes = 2 points
More than 19 minutes = 1 point
Stopped or incomplete = Incomplete
EXERCISE 2: 15 MINUTES* (HANDS OUT FOR LST 2 MINUTES)
Performed satisfactorily = 5 points
Hands not out = 3 points
Bottom or side support = 1 point
Stopped or incomplete = Incomplete
*Treading water, drown proofing, bobbing or floating
EXERCISE 3: 700 M SNORKEL SWIM (FINS & MASK)
Under 15 minutes = 5 points
15-17 minutes = 4 points
17-19 minutes = 3 points
19-21 minutes = 2 points
More than 21 minutes = 1 point
Stopped or incomplete = Incomplete
EXERCISE 4: 100 M INERT RESCUE TOW (WITH FINS)*
Under 2 minutes = 5 points
2-3 minutes = 4 points
3-4 minutes = 3 points
4-5 minutes = 2 points
More than 5 minutes = 1 point
Stopped at any time = Incomplete
*Victim wearing PPE (personal protective equipment)
EXERCISE 5: FREE DIVE TO A DEPYJ OF 3 M & RETRIEVE AN OBJECT
Performed satisfactorily = Pass
Stopped or incomplete = Incomplete
REFERENCES

1. Strauss, M.B., Busch, J.A. & Miller, S.S. 2013. SCUBA in Older Aged Divers. Wound Care and Hyperbaric Medicine, 4(3):27-37.
2. Bove, A.A. 2011. The cardiovascular system and diving risk. Undersea Hyperbaric Medicine, 38(4):261.269.
3. Alert Diver Online. 2012. Matters of the Heart. [Online]. Available at: http://www.alertdiver.com/Matters_of_the_Heart [Accessed: 1 August 2017].
4. Spivey Law Firm. 2015. Are There More Risks For Older Scuba Divers. [Online]. Available at: https://www.spiveylaw.com/blog/are-there-more-risks-for-older-scuba-divers/ [Accessed: 1 August 2017].
5. WebMD. 2003. Scuba Diving Safe for Older Adults. [Online]. Available at: http://www.webmd.com/healthy-aging/news/20030206/scuba-diving-safe-for-older-adults#1 [Accessed: 1 August 2017].
6. Brylske, A. 2016. Dive Training for Aging Divers. Where When How. [Online]. Online Issues March/April. Available at: http://onlineissues.wherewhenhow.com/article/Reprint-+Dive+Training+For+Aging+Divers/2400461/290949/article.html [Accessed: 1 August 2017].
7. Bove, F. n.d. Diving for Seniors. [Online]. Available at: http://www.skin-Diver.com/departments/ScubaMed/DivingforSeniors.asp?theID=331 [Accessed: 1 August 2017].
8. Denoble, P. 2014. Medical Examination of Diving Fatalities Symposium 2014. [Online]. Available at: https://thedivelab.wordpress.com/2014/06/19/medical-examination-of-diving-fatalitiessymposium-2014/ [Accessed: 1 August 2017].
9. Scuba-Doc. 2016. Problem - The Older Diver. [Online]. Available at: http://www.scuba-doc.com/agedvn.htm [Accessed: 1 August 2017].


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