REVIEW ANN MARIE McMULLIN, MD Department of Emergency Medicine, Cleveland Clinic Scuba diving: What you and your patients need to know ■ ABSTRACT ORE THAN 7 MILLION PEOPLE are estimat- M ed to participate in self-contained Self-contained underwater breathing apparatus (SCUBA) underwater breathing apparatus (scuba) div- diving continues to gain popularity. General practitioners ing,1 so you are highly likely to encounter one need to know the health requirements and in your practice. contraindications so they can counsel patients Scuba diving requires rigorous health appropriately. SCUBA diving injuries may not be apparent screening to prevent injury or accidents. Most immediately and require knowledge and understanding reputable diving instructors and schools for accurate diagnosis and treatment. require a medical statement from prospective divers. Health care professionals must be ■ KEY POINTS aware of the requirements, contraindications, and possible injuries of diving so that they are General considerations for diving clearance, requirements able to advise their patients properly and diag- for further workup, and contraindications to diving must nose diving-related injuries. be reviewed for each patient. This article describes general recommen- dations for screening scuba divers and suggests specific workups and contraindications to div- In the event that a patient presents with health concerns ing. It also provides an overview of potential after a diving trip, barotrauma, decompression sickness, diving injuries and their treatment. and air embolus should be considered as possible diagnoses. ■ PREDIVE MEDICAL CLEARANCE Divers Alert Network (DAN) is a good medical resource General considerations for screening patients for physicians and patients should they have more are shown in TABLE 1.2 specific questions. DAN can be contacted at 1-919-684- Each patient should have a predive clear- 2948, www.diversalertnetwork.org, or www.WRSTC.com. ance workup based on his or her medical his- tory and current complaints. The patient’s medical and surgical histories should be reviewed and further evaluation considered on the basis of the medical history (TABLE 2).2–5 A review of systems will ensure that no cur- rent health condition will hinder diving, and a physical examination should be performed to complement the history. Absolute contraindications to scuba div- ing include, but are not limited to, hyper- CLEVELAND CLINIC JOURNAL OF MEDICINE VOLUME 73 • NUMBER 8 AUGUST 2006 711 Downloaded from www.ccjm.org on September 29, 2021. For personal use only. All other uses require permission. SCUBA DIVING McMULLIN TABLE 1 General considerations for assessing capacity to dive Exercise tolerance Equipment is bulky and heavy (> 35 lb) and sometimes must be carried over uneven terrain and for excessive distances or up and down the ladder of a boat Swimming is easier in fins and a buoyancy vest, but is still difficult in certain currents Breathing When ascending from depth, any process that prevents airflow from the lungs (eg, emphysema, bulla, other causes of air trapping) puts the diver at risk for pulmonary overinflation, which can lead to alveolar rupture and air embolus Mental status Life-threatening events can occur underwater that require certain actions A diver must not be at increased risk of change or loss of consciousness such as would occur with a seizure or hypoglycemic episode Panic is a normal response to even non-life-threatening events at depth, but a diver with an abnormal panic or anxiety response may put himself or others at risk if he or she reacts inappropriately Recent health A vomiting or coughing diver can drown A diver with an upper respiratory infection who cannot equalize the pressure in the ears or sinuses can rupture a tympanic membrane or sinus Recent surgical wounds can easily get infected Uncontrolled hypertension puts a diver at increased risk of pulmonary edema Medications Review medications that can alter mental status or impair exercise tolerance The real bottom line is: if a patient requires a medication to dive (eg, a decongestant, antiemetic, antiseizure medication, or antidysrhythmic), he or she should be advised not to dive trophic cardiomyopathy, right-to-left intracar- the unclear risk of fetal emboli. Abnormal diac shunt, seizures, history of cerebrovascular facial anatomy may affect mask or mouthpiece accident, spontaneous pneumothorax, gastric fit. None of these examples is an absolute con- outlet obstruction, recurrent bowel obstruc- traindication, but all must be addressed fully tion, claustrophobia, untreated panic disorder, prior to clearing a patient to dive. A more and numerous ear, nose, and throat disorders. complete list of considerations can be found in The major concern in these cases is sudden TABLE 2. loss of consciousness, increased risk of decom- pression sickness and barotrauma, or risk to ■ POTENTIAL DIVING INJURIES other divers due to inappropriate response to stress while diving. In the unlikely circumstance that you are the There are many other situations in which first person to evaluate a patient for a com- a patient should be cautioned or sent for fur- plaint after a recent diving trip, you should be ther evaluation prior to clearance. For familiar with the potential diving injuries and instance, a history of coronary artery disease their treatment. may necessitate a stress test to prove exercise tolerance. Patients with a pacemaker must Barotrauma ensure the device is certified to withstand Barotrauma can involve any gas-filled body changes in pressure. Patients who have had space and involves tissue damage due to a fail- previous decompression sickness or dive-relat- ure of that space to equalize its pressure with ed injury should have a specialist evaluation the ambient water pressure.6 All forms of prior to clearance to determine risk of recur- barotrauma can occur even at very shallow rence. Pregnant women should be advised of depths if the proper procedure for ascent is not 712 CLEVELAND CLINIC JOURNAL OF MEDICINE VOLUME 73 • NUMBER 8 AUGUST 2006 Downloaded from www.ccjm.org on September 29, 2021. For personal use only. All other uses require permission. SCUBA DIVING McMULLIN followed or if preexisting conditions allow for decompression injury is noted gradually on air trapping. ascent or after exit from the water.7 Middle ear barotrauma. The most prevalent Treatment of inner ear barotrauma injury associated with diving is middle ear baro- involves referral to an otolaryngologist, bed trauma or “ear squeeze.” Middle ear barotrauma rest, elevating the head of the bed to 30 most often occurs on descent when a diver fails degrees, and stool softeners to avoid increas- to equalize the pressure between the air in the ing intracranial pressure. middle ear and the ambient water. Pressure and Sinus, tooth, and facial barotrauma. volume follow Boyle’s law: PV = K (where K is a Barotrauma can also affect the sinuses, caus- constant; at a constant temperature, the volume ing headache, epistaxis, and sinus pain, or the [V] of a gas varies inversely with the pressure [P] teeth, causing localized dental pain, usually at to which that gas is subjected).7 the site of a filling. For example, as a diver descends, the Tooth squeeze will require treatment by a increase in ambient water pressure compresses dentist with replacement or repair of the fill- the gas in air-filled body spaces such as the ing, and sinus barotrauma is treated with middle ear. The diver must address this vol- decongestants.8 If a sinus has ruptured, further ume loss by adding more gas to this space workup is needed to assess for pneumo- (equalizing it) to prevent injury. cephalus, and the patient should be referred to Divers equalize the pressure on descent an otolaryngologist.7 with a gentle Valsalva maneuver, but this Gastric barotrauma. By the same mecha- maneuver may be impaired if the eustachian nism, barotrauma on ascent can occur in the tube is blocked. The external pressure may be gastrointestinal tract, where gas is trapped, so great as to implode (rupture) the tympanic and may lead to rupture of a hollow viscus. membrane, or it may just cause pain and tym- Gastric barotrauma or hollow viscus rup- panic membrane hemorrhage. Other associat- ture is rare but requires emergency treatment. ed symptoms may include vertigo, tinnitus, Pulmonary barotrauma. If the diver and hearing loss. holds his or her breath on ascent and does not The most Treatment of middle ear barotrauma exhale properly or has significant underlying common diving includes decongestants, and if the tympanic pulmonary disease, the lungs can overinflate. membrane is ruptured, the addition of antibi- Overinflation of the lungs can lead to baro- injury is middle otics (only if there is purulent drainage, in trauma of the alveoli, causing them to rupture, ear barotrauma which case one should start with typical treat- with emphysema extending into the neck or ment for otitis media), analgesia, and referral mediastinum, and possibly to air embolus. (‘ear squeeze’) to an otolaryngologist. No diving should be Pneumothorax is rare, but it must be consid- permitted until symptoms are improved and ered if the symptoms are suggestive.9 the tympanic membrane is healed. Pulmonary barotrauma rarely requires Inner ear barotrauma. Similar symptoms specific treatment other than observation, but (vertigo, tinnitus, hearing loss) may occur as indicated in TABLE 2, evaluation by a pulmo- with inner ear barotrauma, which is generally nologist is needed before the patient dives caused by a too-forceful Valsalva maneuver, again. resulting in rupture of the round or oval win- Eye injury. Diving mask pressure must be dow due to unequalized pressure between the equalized by gentle exhalation through the nose middle and inner ear. If inner ear barotrauma on descent; mild superficial trauma can occur to is suspected, no findings will be noted on eval- the skin and eyes in the form of petechiae and uation of the tympanic membrane (which dis- subconjunctival hemorrhages if this is not done.