This three-part series is extracted from a chapter in the second edition of Diving Science by Michael B. Strauss, MD, et al. which covers special diving types, situations and environments. Part 2 of this series in the current issue of WCHM discusses musculoskeletal disabilities, neuropsychiatric disorders, and respiratory problems.
Problems involving the musculoskeletal system are easier to conceptualize as handicaps such as a loss of limb as compared to disabilities such as those imposed by heart disease.
The majority of musculoskeletal handicaps with respect to scuba diving consist of three primary problems: loss of limbs, restricted/painful joint motions and loss of function from neurological conditions. How much they interfere with scuba diving needs to be considered on a continuum from almost none to total prevention of the activity. In the majority of scuba divers with disabilities, the dive buddy is a key factor in making the dive safe and enjoyable.
Loss of Limbs
Trauma and circulation problems are the two most frequent causes of amputations, and most occur in the lower extremities. Those individuals with loss of limbs from circulation problems usually have other significant comorbidities such as heart disease and diabetes and consequently are not candidates for scuba diving. Conversely, much attention has been given to scuba diving in patients with traumatic amputations. This is largely a consequence of affording wounded warriors from military conflicts the benefits and pleasures of scuba diving.
For single leg amputations, the restrictions for scuba diving are minimal. Usually all that is needed is an adaptive fin-prosthesis device (Figure 5). For above-knee and bilateral amputees, the designs are more complicated, with the most challenges being the attachment of the swimming prosthesis to the remaining limb stump. What can be done in this regard is dependent on the motivation of the amputee and the ingenuity of the prosthetist. While the amputee may be totally independent on land with crutches or even without walking aids, the transition from the land to the water environment is the primary challenge. This is where the buddy diver is essential and adaptive devices for the transition may be needed, such as a ramp or hydraulic lift device for water entries and exits.
FIGURE 5. Adaptive Fins for Swimming and Diving
Joint, Ligament, Tendon and Muscle Problems
Arthritis is a condition where body joints including the spine have deterioration of their articular (joint) cartilage and no longer function as smooth guiding surfaces. The loss of cartilage can progress to bone erosion and collapse of the joint surfaces. With such, there is marked restriction of the joint’s motion and associated pain with movement of the joint. With decreased movement, the joint capsules, ligaments and muscle-tendon units contract and loss of joint motion is the result. Pain and loss of joint motion have consequences for the scuba diver. They include interfering with the donning and removing diving gear—especially exposure suits, entries to and exits from the water, and ability to use the extremities at a capacity necessary to extricate themselves from emergencies, such as negotiating currents or extrication from entanglements. When the above are realized, the scuba diver typically “retires” from this activity for the reason it is too difficult and/or it is “no longer fun or enjoyable.”
Although musculoskeletal pain and restricted joint movements for land-based activities may severely curtail activities, the buoyancy effects of water unload joints and need for minimal joint movements for motility make swimming and water aerobics an ideal exercise activity. While these have some relationships to scuba diving, the challenges, as previously mentioned, are donning and removing gear and water entries and exits.
Diving with Joint Replacements
Orthopaedic advancements have greatly expanded the possibilities for those with arthritis problems to dive. These advancements are largely due to the successful outcomes of total joint replacements. Most arthritis problems with respect to scuba diving impose only relative contraindications for scuba diving. Patients with arthritis and/or total joint replacements should not categorically be restricted from scuba diving. There is no data available that patients with total joint replacements have increased incidences of medical problems of diving and, in particular, decompression sickness. Consequently, the decision to scuba dive is primarily a function of the patient’s motivation. However, this must be coupled with the joint surgeon’s approval that the joint replacement is sufficiently healed, stable and functional enough that scuba diving is OK.
FIGURE 6. Musculoskeletal Handicaps that Have Ramifications for SCUBA Diving
Soft Tissue Musculoskeletal Disorders
Other musculoskeletal problems such as shoulder rotator cuff tears, tendinitis, contractures, joint instabilities, knee meniscus tears and low back pain, in general, only impose temporary contraindications for scuba diving, Almost all of these conditions can be mitigated with rest, medications(especially non-steroidal, anti-inflammatory agents), physical therapy and/or surgery. Since conditions just mentioned can interfere with mobility, dive planning and selection of dive sites are important. Conditions to avoid are dive sites where strong currents are present and where water exits require removal of equipment while dangling from a safety line or ladder in turbulent waters.
Osteonecrosis (osteo = bone, necrosis = death) is a condition where bone cells die. It has other names such as avascular necrosis, femoral head necrosis (although it can occur in other bones), bone necrosis, diver’s bone disease and bone rot. Although the etiology has not been clearly established, it is hypothesized that bubbles form in the blood vessels supplying the bone cells, the cells die from hypoxia and if in a joint area, collapse, cause irregularity of the joint surfaces and result in arthritis. There are reported associations of this condition occurring in saturation divers, divers who do repetitive long, deep dives and those divers who have omitted decompression. However, the incidences are so infrequent as compared to post-traumatic, coagulopathy-related and idiopathic age-related, wear-and-tear arthritis, that the significance of the diving activity can be questioned. However, if osteonecrosis occurs in the relatively young diver, the diving history must be considered.
Osteonecrosis is not a disability unless arthritis and joint collapse occurs. If detected, diving practices should be reviewed and avoidance of diving activities that could further the problem avoided. Consequently, osteonecrosis becomes a relative contraindication for scuba and other compressed gas diving. Hyperbaric oxygen has been reported to prevent progression of femoral head necrosis before it progresses to joint collapse.12 If a joint replacement is required, commercial diving activities are not recommended.
However, as mentioned before, with due considerations, scuba diving with joint replacements should be placed in the relative contraindications category.
Spinal Cord Injuries and Peripheral Nerve Problems
Neuropsychiatric disorders have two major components, those that affect the brain and those that affect spinal cord/peripheral nervous system. Spinal cord and peripheral nervous system problems mainly concern loss of function. Paraplegic patients who have plateaued in their recovery present relative contraindications for diving. Wounded warriors and other athletic individuals are the major candidates for scuba diving.
Motivation of the paraplegic diver is the key factor in association with a high level of fitness and a nearly ideal body mass index. Next is establishing a dedicated support team. This includes usual and customary scuba diving training as well as the unique considerations for how to deal with functionless, insensate lower extremity limbs in an environment that provides near neutral buoyancy. The dive buddy and support team need to help with donning and removing diving gear and water entries and exits as well as guiding the handicapped diver through the course of the dive. Of special concern is avoiding the dandling of paralyzed lower extremities onto potential injury-producing marine animals such as barnacles, sea urchins and fire corals.
TABLE 5. Mental Conditions and Diving
||Concerns and Recommendations for Diving
||Similar to development delays
||If affliction is mild and especially if the patient enjoys the water and had dove before, diving in controlled environments may be beneficial
(less severe than neuroses)
|Innate fear of water, drowning, or sharks while able to function well in other situations
||As with neuroses diving should not be forced on people with anxiety disorders for aquatic environments
||Lack of communication skills, inability to pay attention, lack of interest
||If successfully snorkels, then with close supervision in controlled environments, diving may have therapeutic benefits
||Uncontrolled muscle movements, lack of coordination, spasticity, contractures
||Mobility limitations: difficulty handling diving gear, donning and removing it. If mild, planned diving with supervision OK
|Developmental Delay/Mental Retardation
||Inability to understand or follow instructions. Subject to panicking and doing dangerous things such as "bolting" to the surface breathing or descending to dangerous depths
||If moderate to mild impairment, close supervision in controlled environments possibly OK for diving. Better to teach and engage in snorkeling activities
||Anxiety, obsessive-compulsive behavior, lack of focus extends to all activities
||Spectrum ranging from complete avulsion to diving, sharks, etc. to obsessions with safety, hygiene, contaminants, pollution and behavior that interferes with other divers' enjoyment
|Post Traumatic Stress Disorder
||Analogous to neuroses
||Diving may be a superb diversionary activity with the water environment; supervisions and controlled environments are essential
||Depression, mania, paranoia
||Suicidal behavior, risky activities, harm to others due to hallucinations, loss of reality, or wanting to hurt others. Diving not recommended
||Drug use, intoxications, deviant behavior
||Safety concerns regarding diving; makes the diving experience potentially dangerous for others
|Traumatic Brain Injury
||Similiar to Alzheimer's
||Similar recommendations to Alzheimer's
The third consideration is selection of the “ideal” diving site where minimal cold water exposure gear and weights to establish neutral buoyancy are needed, water entries and exits are easy (such as off of a boat), the water visibility is good, and waves, currents or swells are at a minimum. The dive profiles should be very conservative because the on and offgassing of nitrogen is likely to be much different in extremities that are immobile due to the paralysis. Mixed gas and closed-circuit rebreather scuba diving is not recommended for the paraplegic patient. Not unexpected, it is likely to be very satisfying psychologically for a paralyzed diver to “conquer” the aquatic environment and do things most terrestrial bound people are afraid and/or are unwilling to do. Likewise, for the dive buddy it is a real achievement and a measure of the highest level of scuba diving skills to be able to execute safely the diving activity for the handicapped diver.
Other nerve-related disorders such as carpal tunnel syndromes, tennis elbow, diabetic neuropathy, peripheral neuritis, sciatica, radicular pain, etc., present relative contraindications to diving. Most are remedial with medication and/or surgical management. The physician attending to the patient’s problem can usually provide clearance for scuba diving. If in doubt, referral to a diving medicine physician for advice is recommended.
Vision and Other Sensory Organ Impairments or Losses
The major considerations are those that deal with hearing, vision and sensation. Much has been written about scuba diving with eye conditions; most are relative or temporary (e.g. after surgical procedures) contraindications for scuba diving.13 Radial keratotomy and laser refractive surgery (photorefractive keratotomy) impose only temporary contraindications for scuba diving that allow time for healing. The ophthalmologist performing the surgery is expected to provide the clearance as when it is OK to scuba dive after such procedures.
More common considerations are diving with impaired vision, which can usually be managed with corrective lenses. Contact lens use is not a contraindication for scuba diving. Loss of near vision (myopia) is commonly associated with aging. This is somewhat mitigated by the magnification effect of the facemask-water interface, which makes objects appear about a third larger than when visualized in air. Corrective lenses attached to the face mask are a solution to impaired near vision. A more important safety concern is that the loss of near vision makes the reading of dive monitoring equipment difficult and is a reason not to scuba dive without lenses to correct this problem. While blindness is not a contraindication for scuba diving, anecdotal reports exist that legally blind (vision less than 20/200) have done and enjoy scuba diving.14 Loss of color vision is not a contraindication for scuba diving, except for Naval Special Warfare divers (SEALS) and Explosive and Ordinance Demolition (EOD) divers because of the need to differentiate color-coded wiring for setting-up and deactivating demolitions.
While glaucoma is not a contraindication for scuba diving, medications to manage it can affect heart rate and becomes a consideration if cardiac conditions are present.
Impaired and total loss of hearing are different considerations. Age-related decreases in hearing (presbycusis), most noticeable with high frequency sounds, is not a contraindication to scuba diving. However, total deafness in one ear is considered by many to be an absolute contraindication to scuba diving. This is because ear structures are among the most vulnerable of all body structures to barotrauma, and diving presents constant, invariable challenges to these structures. Meniere disease is an absolute contraindication for diving.
Its symptoms include vertigo nausea, vomiting, tinnitus and hearing loss. The hearing loss tends to fluctuate but worsens with time.
Sensation has many components such as pain, light touch, two-point discrimination, pressure, stretch/distraction, temperature, and vibration recognition and discrimination. Each has its own sensory organelles for recognition, but the nerve impulses must be transmitted to the brain where they can be interpreted by the sensory cortex. Any perturbation along this transmission and interpretation chain can cause disordered or loss of sensation. While this may seem insignificant since vision is the overwhelming sensory experience during diving, it may have consequences for grasping objects, appreciating marine animal injuries, protecting from cold exposure, and handling safety equipment. Again, dive planning and dive buddies can compensate for diving with rare and unusual sensory nerve problems resulting from diabetes mellitus, trauma, multiple sclerosis, radiculopathies (impingement of nerves leaving the spinal cord), and nerve compression syndromes such as carpal tunnel syndrome.
Psychiatric and Brain Function Disorders
Of all the disabilities and handicaps that can confront the scuba diver, these are the most difficult for which to provide concrete recommendations. They encompass a spectrum of disorders in alphabetical order from Alzheimer’s disease, to anxiety disorders, to autism, to cerebral palsy, to developmental delay/mental retardation, to neuroses, to post-traumatic stress disorder, to psychoses, to sociopathic behavior, to traumatic brain injury (Table 5). Not to be overlooked in this spectrum is the recognition how scuba diving has benefited those with autism, traumatic brain injury and post-traumatic stress disorder.15,16
Scuba diving requires a complement of cognitive skills, coordination abilities, interpretations of sensory input, and integrations of motor (muscle) activity. In making decisions about diving, the most likely factor to interfere with the diving activity and/or make the risks of a problem arising during the dive must be considered the critical variable in making the decision (Table 5). The decision to consider or not recommend scuba diving, consequently, rests on input from a variety of sources as well as the patient's own functional abilities, cognitive skills and desires. Not to be disregarded is a diving physician’s role to advise and consent on the diving conditions that would be appropriate for the handicaps in question. The other prerequisites for scuba diving with patients who have mental conditions are diving in a controlled environment with adequate and attentive supervision.
Respiratory System Problems
The respiratory system has a multitude of components from the openings of the mouth and nose to the conduits such as pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles, to the alveoli where air exchange occurs, to the lining of the lungs (the pleura), to the alveolar capillaries, to the diaphragm and accessory respiratory muscles, to the rib cage. Each component has conditions that can impose restrictions on divers (Table 6). Two main conditions, asthma and pneumothorax, generate the most questions about making decisions and imposing restrictions on scuba diving. Almost all the other conditions have obvious contraindications for scuba diving or the conditions only impose temporary restrictions as documented in the above-cited table.
This condition occurs in about five percent of the population and is a leading cause of illness and restriction of activities in childhood and adolescent age groups. It is a disorder that can be chronic or have acute exacerbations characterized by widespread and largely reversible reductions in the caliber of bronchi and bronchioles due in varying degrees of smooth muscle spasm, mucosal edema, and excessive mucus in the lumens of airways.17 Asthma can impose both absolute and relative contraindications for scuba diving. The main concern with asthma is air retention in the alveoli as a consequence of bronchiole constriction. This interferes both with alveolar filling and alveolar emptying of gas. The consequence of the former is hypoxia and its consequences of inadequate oxygenation of tissues. The consequence of failure to empty is gas retention in the alveoli. This results in carbon dioxide retention plus hypoxia. In the case of a scuba diver, air retention in the alveoli can result in their rupture during ascent as the gas expands in accordance with Boyle’s law. A spectrum of problems collectively termed as extra-alveolar air syndromes can arise from subcutaneous/ mediastinal emphysema to pneumothorax to arterial gas embolism.
TABLE 6. Respiratory System and Its Relevance to Diving
|Mouth & Nose
||Gas exchange with outside environments or scuba regulator
||Upper respiratory infections, congestion can interfere with middle ear clearing
||Gas conduct from mouth/nose to respiratory tract
||Inflammation tonsillitis; as above regarding middle ear barotrauma
||Temporarily vs. absolute if chronic & unable to clear ears
||Separate alimentary tract from airways tract
||As above; tracheotomy for reducing dead space of upper airways
||Inflammations temporary; tracheotomy absolute
||Major conduit from bronchi
||Inflammation; respiratory tract infections e.g. tracheitis
||Two main divisions of the respiratory tree (RT)
||Same as above; e.g. bronchitis
||Temporary if acute; relative if chronic and associated with coughing & secreations
||Further divisions of RT with 28 in total
||Same as above; e.g. bronchiolitis
||Same as above
||Muscular control of passage to alveoli; account for 10% of gas exchange
||Bronchial spasm with restriction of gas passage to alveoli. Partial or complete obstruction from secretions
||Relative vs. absolute depending on severity; see Asthma in text
||90% of gas exchange (e.g. O2 in and CO2 out)
||Distention as in chronic obstructive pulmonary disease (COPD), collapse as in atelectasis and/or scaring as in pulmonariy fibrosis; pneumothorax
||Absolute except pneumothorax (see text)
||Gas transport to bloodstream before & after exchange at above 2 levels
||Ventilation-perfusion inequalities; pulmonary emboli
||Absolute; if resolved then relative
||Primary motor/muscle system for moving air in &o out of lungs
||Paralysis; bowel herniation through diaphragm into chest cavity
|Accessory Respiratory Muscles
||Increase ventilation. Compensate for loss of diaphragm function
||Paralysis in high spinal cord injury
In the “Diving in Youth” chapter (Chapter 14), the subject of scuba diving in this age group was detailed. The advice is much the same for the adult scuba diver and imposes a relative restriction. Often childhood asthmatics grow out of their asthma attacks, perhaps by enlargement of airways with growth, a less responsive immune system and/or learning to avoid precipitating factors that initiate the asthma attacks. However, another permutation of asthma is the adult onset asthma presentation. If asthma episodes are infrequent and chronic medications are not required, the patient with a history of asthma should be allowed to scuba dive if asymptomatic and not requiring medications to control his or her breathing before, during and after scuba diving activities. Hydration and avoidance of chilling are important considerations in choosing a diving site since cold air can lead to bronchiole spasm and dehydration leading to excessive and/or inspissation (thickening) of the mucus secretions in the respiratory system. This can further interfere with gas exchange and its consequences of hypoxia and alveolar gas retention.
FIGURE 7. Extra-alveolar air/ Pulmonary Over Pressurization Syndromes
This is a condition where gas escapes from the alveoli either spontaneously or after trauma and insinuates itself between the lung pleura (covering membrane) and the lung tissue itself. If leakage is significant, the lung collapses. If the collapsed lung and filling of the pleural space continues unabated, it will compress the unaffected lung leading to the potentially fatal situation of tension pneumothorax. Pneumothoraxes occur rarely in scuba diving with subcutaneous/mediastinal and arterial gas embolism being more frequently reported. Reasons for this are not clear, but probably represent anatomical differences with respect to the anatomy of the interfaces between conduits and the surrounding supporting soft tissues such as the lung pleura. Pulmonary blebs also need to be considered as a cause of the spontaneous pneumothorax. The consensus is that if a spontaneous pneumothorax occurs, the patient should not be allowed to scuba dive. The rationale for this is based on the assumption there is a "weak link" in the respiratory system anatomy and the changes of ambient pressure associated with scuba diving make the diver vulnerable to further extra-alveolar air problems. The US Navy has imposed a restriction on submariners and divers that if a spontaneous pneumothorax occurs, the patient can only resume diving and submarine activities if they remain asymptomatic for five years.
The situation is different for the traumatic pneumothorax because of two considerations. First, there is an identifiable cause such as a fractured rib for the lung collapse, and with healing of the traumatic pneumothorax, there is usually a scar tissue formation reaction around the injured lung tissue, so that it is theoretically more resistant to a pneumothorax than the uninvolved lung tissue. For this reason, patients with traumatic pneumothoraxes are allowed to resume scuba diving when healed, asymptomatic and cleared by the physicians attending to the pneumothorax. The time interval from injury to resuming scuba diving is generally about six months.
Subcutaneous and Mediastinal Emphysema
These are the least serious of the spectrum of extra-alveolar air syndromes. They are believed to be caused by gas escaping the respiratory tree probable at the alveolar level and moving through the hilum of the lung into the mediastinal and/or subcutaneous tissues rather than remaining in the chest cavity (which would lead to a pneumothorax). Since they are associated with scuba diving, over expansion of the lungs with ascent and rupture of the alveoli is the proposed mechanism. Why presentations vary from mediastinal to subcutaneous locations (as well as not having associated pneumothorax) is not known, but probably reflects individual differences in divers’ respiratory system anatomy. Mediastinal emphysema (pneumomediastinum) is characterized by chest pain and labored breathing and is confirmed by chest X-rays.
Subcutaneous emphysema symptoms include crepitus (bubbly, sponge-like feeling) of the skin on the neck and lower face from gas dissecting in the subcutaneous tissue planes. The bubbles in this location can also cause changes in the voice, such that the victim sounds like Donald Duck when speaking.
Subcutaneous and mediastinal emphysema (SE/ME) are self-limiting conditions with spontaneous resolution of the gas with time, usually a week or so. The consensus is that these events do not impose restrictions for future scuba diving. Usually, a detailed history of the dive activity preceding SE/ME can detect breath-holding or unanticipated, rapid ascent portions of the dive. Consequently, the diver should be informed of the probable mechanism of SE/ME and be cautioned to avoid uncontrolled ascents and not to breath-hold during the ascents. If the diver experiences a second occurrence of SE/ME, scuba diving becomes a relative contraindication. In such situations, the diver should be evaluated by a chest medicine physician with imaging studies to rule out lung blebs or other lung pathology before resuming diving.
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