UC San Diego Team Publishes Guidelines For Post-Coronavirus Diver Medicals
A new study by researchers at the University of California, San Diego has given updated guidelines for the conduct of scuba diving medicals for divers who may have suffered from Covid-19.
The report, 'Diving after SARS-CoV-2 (COVID-19) infection: Fitness to dive assessment and medical guidance', was published in the journal Diving and Hyperbaric Medicine after a team led by lead author Dr Charlotte Sadler, of the Department of Emergency Medicine, Division of Hyperbaric Medicine at UC San Diego's School of Medicine, analysed the known effects of Covid-19 on the human body, together with comparative research based on the long-term effects of similar viruses.
Problems for divers who have been infected with SARS-CoV-2 were postulated shortly after the pandemic became widespread. A medical doctor in Austria published a letter in German magazine Wetnotes as far back as April 2020 with concerns that the long-term physiological effects of Covid-19 on patients – who might otherwise be completely asymptomatic and feeling entirely normal – may go unnoticed without a more extensive medical investigation than would usually be required for divers.
'The diving medicine community is presented with the challenge of performing fitness to dive evaluations in the context of a disease in which the natural history is currently unknown,' writes Dr Sadler in the report. 'In what is known of [Covid-19's] pathophysiology the pulmonary, cardiac, and [blood-clotting] effects seem to be very relevant to divers.'
While Covid-19 primarily affects the respiratory system, which is already a concern for divers, it has been shown that severe cases of the disease can cause damage to the heart, 'potentially increasing the risk of barotrauma, and also decreased exercise tolerance and increased susceptibility to cardiac events such as heart failure, pulmonary oedema, and arrhythmias,' according to the report.
The recommendations for medical examination are split into four categories, depending on the severity of illness experienced by each diver. Category 0 is defined as a diver who had never experienced any symptoms of the disease, even if they had tested positive for Covid-19; Category 1 is for divers who had a 'mild' case, where hospitalisation and the provision of emergency oxygen were not required; Category 2 for a 'moderate' case, in which treatment for Covid-19 included the provision of emergency oxygen but not mechanically assisted ventilation; and Category 3 for the most severe cases, for those who required treatment in an intensive care unit.
Regardless of the category in which a diver might belong, they must be entirely asymptomatic and have 'returned to their baseline exercise tolerance' before undergoing a medical evaluation. In other words, they should be able to perform the same level of exercise as they were prior to infection with SARS-CoV-2 without getting easily winded or requiring longer recovery times. 'Further testing and investigation' should be carried out if divers exhibit 'even minor deviations from their baseline.' Since that baseline will differ between individuals, physicians who are concerned about a diver's 'self-reported exercise level' should check to see if it 'warrants an appropriate exertional test for diving.'
The level of medical examination required for each category is described fully in the UC San Diego Guidelines for Evaluation of Divers document but ranges from 'no additional testing required' and following the general RSTC (or equivalent) guidelines for Category 0 divers, to echocardiograms and measurement of oxygen saturation levels while exercising, and blood tests to check for the presence of damage to the heart for those in Category 3.
Divers who exhibit any symptoms of either Covid-19, or potentially what is now being referred to as 'long Covid' – ie continuing symptoms of conditions caused by the initial infection – are to be automatically precluded from diving. According to the report, however, this does not necessarily represent a lifetime ban on diving 'as many of the sequelae [(ongoing conditions)] which are currently disqualifying (such as abnormal CT scans) may resolve over the next 3-6 months and re-testing may be indicated.'
The advice from the team at UC San Diego follows on from that given by the Belgian Society for Diving and Hyperbaric Medicine in April, recommending that divers wait up to three months before returning to the water following any coronavirus-related symptoms. As the UC San Diego report notes: 'It is likely that all divers who have contracted Covid-19 will require a medical evaluation prior to a return to diving, with emphasis upon pulmonary and cardiac function as well as exercise capacity.'
The guidelines issued by the hyperbaric physicians of the University of San Diego can be downloaded in full from the UCSD website. The original paper, 'Diving after SARS-CoV-2 (COVID-19) infection: Fitness to dive assessment and medical guidance' by Dr Charlotte Sadler et al can be read in the Diving and Hyperbaric Medicine online journal.