Asthma and Diving - A Case Study

Case

A 14-year-old boy and his mother present to your pediatric clinic in preparation for their upcoming vacation to Hawaii. They plan to fly between the different islands and would like to SCUBA dive and hike at different locations. The patient has never been diving before and his mother would like him to be cleared medically before their trip. The patient’s medical history is significant for asthma during the winter that is well controlled with a short-acting beta-2 agonist inhaler. Review of symptoms is positive for a slight head cold and nasal congestion. The patient reports that this is well controlled with over the counter medication. The boy’s BMI is 27.5 and his vital signs are within normal limits.

Questions:

1. Is the patient old enough to dive?

2. Is there any information with regards to their travel planning that is concerning?

3. What are the recommendations for patients diving with a history of asthma?

4. How should the patients cold and congestion symptoms be treated?

5. Does the patient’s weight prevent him from diving?

Answers:

1. Is the patient old enough to dive? Yes, the Professional Association of Diving Instructors allows students as young as 10 years old to take diving lessons.1

2. Is there any information with regards to their travel planning that is concerning? The family plans to fly to several different islands during their vacation. While diving after flying is usually not a problem, flying after a diving session can be dangerous. Excess nitrogen that has accumulated in the blood under oceanic pressures can expand into gas when patients ascend to higher altitudes. These gas bubbles may accumulate in various compartments of the body leading to decompression sickness or, “The Bends.” Even though the cabins of commercial aircraft are pressurized, this pressure is less than found at sea level, with typical cabin pressures being equivalent to approximately 6000-8000 feet.2 The Diver’s Alert Network recommends waiting 12 hours after a single, non-decompression dive, or 18 hours after multiple or deeper dives before flying.3 Hiking at high altitude after diving can also be dangerous for similar reasons. As the Hawaiian Islands have several mountains that exceed 10,000 feet in altitude, the family should take the same precautions as flying when traveling to these areas.4

3. What are the recommendations for patients diving with a history of asthma? Asthma should be considered a serious medical condition in someone considering SCUBA diving for a few reasons: First, asthma as an obstructive lung disease has the potential to cause air trapping in which air cannot fully evacuate from the lung. This can be dangerous while ascending during a dive because as the diver ascends pressure decreases and trapped air expands. Normally this is not a problem as air easily escapes during normal breathing. However, in an asthmatic expansion of trapped air could lead to lung rupture and pneumothorax formation. Second, the narrowing of airways associated with asthma causes an increased amount of work with breathing due to increased resistance of the airways. A diver already has a similar increased work of breathing due to the resistance of using a regulator and the increased density of air at depth.5 Third, many asthmatics experience exacerbations due to exercise, cold air, upper respiratory tract infections, pollen, or emotional triggers. The strenuous nature of diving, in addition to the accidental ingestion of cold salt water, could trigger an acute asthma exacerbation. In addition, the experience of diving could trigger an emotional attack, especially in someone new to diving. An asthma attack while diving could be deadly as the diver would not have immediate access to an inhaler or emergency medical services. The United Kingdom Diving Medical Committee (UKDMC) has released clinical opinions to assist with decision making for asthmatics interested in diving. Although they recommend that asthma secondary to exercise, cold, or emotions be a contraindication to diving, they do have recommendations for further testing that may help with making a decision to dive. Regardless, they list asthma of any type and under 16 years of age as a contraindication to diving.6 The South Pacific Underwater Medicine Society (SPUMS) has produced a report detailing the suggested assessment for potential divers. SPUMS recommends a combination of spirometry and bronchial provocation testing to determine if an asthmatic can safely dive. SPUMS advises against diving for patients who fail either of these tests.7

4. How should the patients cold and congestion symptoms be treated? The patient should postpone diving until the symptoms have resolved. The patient’s congestion should not be treated pharmacologically in order to dive. An inability to equalize pressure in the Eustachian tubes or sinuses will prevent a diver from descending properly. While these problems can be treated with over the counter medications, there is a concern that these medications could wear off during the course of a dive and prevent the diver from being able to properly equalize during ascent leading to air trapping and conditions secondary to air trapping including barotitis, pneumothorax, etc.

5. Does the patient’s weight prevent him from diving? A BMI of 27.5 is classified as overweight. While this is certainly not a contraindication to diving, an evaluation of the patient’s exercise capacity should be evaluated. Diving can be a strenuous activity especially if an emergent situation develops and in some cases an increased BMI can be indicative of a decreased capacity for exercise that may impact diving performance.

Conclusion

According to the United Kingdom Diving Medical Committee this patient should not dive based on age and his history of asthma. If the patient strongly desires to dive extra testing and use of the criteria produced by the SPUMS can be used. Regardless, snorkeling may be a more appropriate activity at this time. Brief counseling on the recommendations of flying after diving would be beneficial to the family, as well as to warn them of the dangerous associated with diving while congested in the event that the patient’s respiratory illness is transmitted to other family members.

Additional Resources

The Diver’s Alert Network (DAN), the United Kingdom Diving Medical Committee (UKDMC), the South Pacific Underwater Medicine Society (SPUMS), and the U.S. Navy are excellent resources to help answer diving related medical questions. Links to their medical sections are listed below:

DAN: http://www.diversalertnetwork.org/medical/faq/ UKDMC: http://ukdmc.org/medical-conditions/ SPUMS: http://www.spums.org.au/public-file-download/full-spums-medical

U.S. Navy Diving Manual Revision 6: http://www.navsea.navy.mil/Portals/103/Documents/SUPSALV/Diving/Dive%20Manual%20Rev%206%20with%20Chg%20A.pdf

References

1. Open Water Diver. Professional Association of Diving Instructors Web site. https://www.padi.com/padi-courses/open-water-diver Accessed August 30, 2016.

2. Cabin Air Pressure. World Health Organization Web site. http://www.who.int/ith/mode_of_travel/cab/en/ Accessed August 30, 2016.

3. Flying After Diving. Divers Alert Network Web site. http://www.diversalertnetwork.org/medical/faq/Flying_After_Diving Accessed August 30, 2016.

4. Highest Mountain in the World. Geology.com Web site. http://geology.com/records/highest-mountain-in-the-world.shtml Accessed August 30, 2016.

5. Lisle Dear, G. D., M.B., FRCA. Asthma & Diving. Divers Alert Network Web site. http://www.diversalertnetwork.org/medical/articles/Asthma_Diving Accessed August 30, 2016.

6. Asthma. UK Diving Medical Committee Web site. http://ukdmc.org/asthma/ Accessed August 30, 2016.

7. Suggested Assessment for the Diver with Asthma. South Pacific Underwater Medicine Society Web site. http://www.spums.org.au/sites/default/files/member_downloads/Suggested assessment for the diver with asthma.pdf Published 2010. Accessed September 1, 2016.

8. Gray, J.G. U.S. Navy Diving Manual Revision 6. Naval Sea Systems Command; October 15, 2011.