Rabu, 30 Mei 2012

Scuba diving: What you and your patients need to know

Department of Emergency Medicine, Cleveland Clinic
Scuba diving:
What you and your patients
need to know
Self-contained underwater breathing apparatus (SCUBA)
diving continues to gain popularity. General practitioners
need to know the health requirements and
contraindications so they can counsel patients
appropriately. SCUBA diving injuries may not be apparent
immediately and require knowledge and understanding
for accurate diagnosis and treatment.
                  7 MILLION PEOPLE are estimat-
            to participate in self-contained
underwater breathing apparatus (scuba) div-
ing,1 so you are highly likely to encounter one
in your practice.
    Scuba diving requires rigorous health
screening to prevent injury or accidents. Most
reputable diving instructors and schools
require a medical statement from prospective
divers. Health care professionals must be
aware of the requirements, contraindications,
and possible injuries of diving so that they are
able to advise their patients properly and diag-
nose diving-related injuries.
    This article describes general recommen-
dations for screening scuba divers and suggests
specific workups and contraindications to div-
ing. It also provides an overview of potential
diving injuries and their treatment.
M ed
General considerations for diving clearance, requirements
for further workup, and contraindications to diving must
be reviewed for each patient.
In the event that a patient presents with health concerns
after a diving trip, barotrauma, decompression sickness,
and air embolus should be considered as possible
Divers Alert Network (DAN) is a good medical resource
for physicians and patients should they have more
specific questions. DAN can be contacted at 1-919-684-
2948, www.diversalertnetwork.org, or www.WRSTC.com.
General considerations for screening patients
are shown in TABLE 1.2
    Each patient should have a predive clear-
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-

TA B L E 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
  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
 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-
diac shunt, seizures, history of cerebrovascular
accident, spontaneous pneumothorax, gastric
outlet obstruction, recurrent bowel obstruc-
tion, claustrophobia, untreated panic disorder,
and numerous ear, nose, and throat disorders.
The major concern in these cases is sudden
loss of consciousness, increased risk of decom-
pression sickness and barotrauma, or risk to
other divers due to inappropriate response to
stress while diving.
     There are many other situations in which
a patient should be cautioned or sent for fur-
ther evaluation prior to clearance. For
instance, a history of coronary artery disease
may necessitate a stress test to prove exercise
tolerance. Patients with a pacemaker must
ensure the device is certified to withstand
changes in pressure. Patients who have had
previous decompression sickness or dive-relat-
ed injury should have a specialist evaluation
prior to clearance to determine risk of recur-
rence. Pregnant women should be advised of
the unclear risk of fetal emboli. Abnormal
facial anatomy may affect mask or mouthpiece
fit. None of these examples is an absolute con-
traindication, but all must be addressed fully
prior to clearing a patient to dive. A more
complete list of considerations can be found in
In the unlikely circumstance that you are the
first person to evaluate a patient for a com-
plaint after a recent diving trip, you should be
familiar with the potential diving injuries and
their treatment.
Barotrauma can involve any gas-filled body
space and involves tissue damage due to a fail-
ure of that space to equalize its pressure with
the ambient water pressure.6 All forms of
barotrauma can occur even at very shallow
depths if the proper procedure for ascent is not

The most
common diving
injury is middle
ear barotrauma
(‘ear squeeze’)
followed or if preexisting conditions allow for
air trapping.
     Middle ear barotrauma. The most prevalent
injury associated with diving is middle ear baro-
trauma or “ear squeeze.” Middle ear barotrauma
most often occurs on descent when a diver fails
to equalize the pressure between the air in the
middle ear and the ambient water. Pressure and
volume follow Boyle’s law: PV = K (where K is a
constant; at a constant temperature, the volume
[V] of a gas varies inversely with the pressure [P]
to which that gas is subjected).7
     For example, as a diver descends, the
increase in ambient water pressure compresses
the gas in air-filled body spaces such as the
middle ear. The diver must address this vol-
ume loss by adding more gas to this space
(equalizing it) to prevent injury.
     Divers equalize the pressure on descent
with a gentle Valsalva maneuver, but this
maneuver may be impaired if the eustachian
tube is blocked. The external pressure may be
so great as to implode (rupture) the tympanic
membrane, or it may just cause pain and tym-
panic membrane hemorrhage. Other associat-
ed symptoms may include vertigo, tinnitus,
and hearing loss.
     Treatment of middle ear barotrauma
includes decongestants, and if the tympanic
membrane is ruptured, the addition of antibi-
otics (only if there is purulent drainage, in
which case one should start with typical treat-
ment for otitis media), analgesia, and referral
to an otolaryngologist. No diving should be
permitted until symptoms are improved and
the tympanic membrane is healed.
     Inner ear barotrauma. Similar symptoms
(vertigo, tinnitus, hearing loss) may occur
with inner ear barotrauma, which is generally
caused by a too-forceful Valsalva maneuver,
resulting in rupture of the round or oval win-
dow due to unequalized pressure between the
middle and inner ear. If inner ear barotrauma
is suspected, no findings will be noted on eval-
uation of the tympanic membrane (which dis-
tinguishes it from middle ear barotrauma). It
must, however, be distinguished from inner
ear decompression injury, as the treatments
for each are markedly different. The two con-
ditions can usually be distinguished by the his-
tory. Barotrauma more often occurs on
descent and continues thereafter, whereas
decompression injury is noted gradually on
ascent or after exit from the water.7
     Treatment of inner ear barotrauma
involves referral to an otolaryngologist, bed
rest, elevating the head of the bed to 30
degrees, and stool softeners to avoid increas-
ing intracranial pressure.
     Sinus, tooth, and facial barotrauma.
Barotrauma can also affect the sinuses, caus-
ing headache, epistaxis, and sinus pain, or the
teeth, causing localized dental pain, usually at
the site of a filling.
     Tooth squeeze will require treatment by a
dentist with replacement or repair of the fill-
ing, and sinus barotrauma is treated with
decongestants.8 If a sinus has ruptured, further
workup is needed to assess for pneumo-
cephalus, and the patient should be referred to
an otolaryngologist.7
     Gastric barotrauma. By the same mecha-
nism, barotrauma on ascent can occur in the
gastrointestinal tract, where gas is trapped,
and may lead to rupture of a hollow viscus.
     Gastric barotrauma or hollow viscus rup-
ture is rare but requires emergency treatment.
     Pulmonary barotrauma. If the diver
holds his or her breath on ascent and does not
exhale properly or has significant underlying
pulmonary disease, the lungs can overinflate.
Overinflation of the lungs can lead to baro-
trauma of the alveoli, causing them to rupture,
with emphysema extending into the neck or
mediastinum, and possibly to air embolus.
Pneumothorax is rare, but it must be consid-
ered if the symptoms are suggestive.9
     Pulmonary barotrauma rarely requires
specific treatment other than observation, but
as indicated in TABLE 2, evaluation by a pulmo-
nologist is needed before the patient dives
     Eye injury. Diving mask pressure must be
equalized by gentle exhalation through the nose
on descent; mild superficial trauma can occur to
the skin and eyes in the form of petechiae and
subconjunctival hemorrhages if this is not done.
Decompression sickness
One form of decompression illness, termed
decompression sickness or “the bends,” results
from the inflammatory response to bubbles of
inert gas forming in the blood and body tissues
when the pressure is significantly and rapidly

TA B L E 2
Suggested predive evaluation based on medical history
Cardiovascular conditions
  Coronary artery bypass grafting
  Percutaneous coronary angioplasty
  Coronary artery disease
    Concerns: Exercise tolerance is vital to diving—a
     stress test in which 13 metabolic equivalents (METs) is
     accomplished with no electrocardiographic changes or
     symptoms is required for clearance to dive if ability is in
     question and may be helpful for coronary artery disease
     risk assessment in patients > 40 years old
  Congestive heart failure
    Concerns: Significantly decreased left ventricular function
     may affect the body’s ability to handle the excess volume
     load, as the body shunts blood centrally in cold water,
     putting patients at increased risk of pulmonary edema.
  Dysrhythmia requiring medication
  Significant valve regurgitation
    Concerns: Consider the condition that necessitated
    Pacemaker must be certified to withstand pressure
     changes involved in recreational diving
Cardiovascular contraindications
  Intracardiac right-to-left shunt
    Concerns: Increased risk of venous emboli entering the
     cerebral and spinal cord circulation
  Hypertrophic cardiomyopathy and valvular stenosis
    Concerns: Increased risk of unconsciousness during exertion
  History of ventricular tachycardia or > 1 episode of
    sustained ventricular tachycardia
Neurologic conditions
  Complicated migraines
  Head injury
  Herniated nucleus pulposus
  Multiple sclerosis
  Trigeminal neuralgia
  History of cerebral gas embolism
    Concerns: Ability to exercise in patients with certain
     neurologic disorders should be considered
    Patients with symptoms that come and go may be
     incorrectly diagnosed with decompression sickness if
     symptoms present after diving
    Risk of seizure should be considered
    Those with previous cerebral embolism must be fully
     evaluated to determine that risk of recurrence is low
Neurologic contraindications
  History of seizure other than childhood or febrile
   Concerns: Significant probability of unconsciousness
     puts a diver at risk of drowning
  History of transient ischemic attack or cerebrovascular
   Concerns: Spinal cord or brain areas with abnormal
     perfusion may increase risk of decompression sickness
  History of previous serious decompression sickness with
   residual deficit
Pulmonary conditions
  Asthma or reactive airway disease
  Exercise-induced bronchospasm
  Solid, cystic, or cavitating lung lesion
  Pneumothorax secondary to thoracic surgery, trauma, or
    previous dive injury
  History of immersion pulmonary edema
  Other previous lung-related dive injury
  Interstitial lung disease
    Concerns: Any active disease, abnormal pulmonary
      function tests, or positive exercise challenge is very
      worrisome for diving
    Increased risk of breathing challenge with scuba
      device as well as possible increased risk of pulmonary
    Forced expiratory volume in 1 second and peak
      expiratory flow rate should be within normal limits for
      diver’s age, sex, race, and height
    Exercise test should be negative
    Pulmonology consult should likely be arranged before
      clearance for diving in any of these cases
Pulmonary contraindications
  History of spontaneous pneumothorax
Gastrointestinal conditions
  Peptic ulcer disease associated with pyloric obstruction
  Severe gastroesophageal reflux disease
  Unrepaired hernia of the abdominal wall big enough to
    become incarcerated
    Concerns: The concern is for air trapping and
      expanding on ascending
  Inflammatory bowel disease (if debilitating)
    Concerns: May impair abilities, or if diving in distant
      locale, treatment may not be available
C O N T I N U E D O N PA G E 7 1 9

TA B L E 2 C O N T I N U E D F R O M PA G E 7 1 6
Gastrointestinal contraindications
  Gastric outlet obstruction of a degree sufficient to
   produce recurrent vomiting
   Concerns: May cause vomiting, which can lead to drowning
  Chronic or recurrent small-bowel obstruction
  Periesophageal hernia
   Concerns: Air trapping and expansion could lead to rupture
Orthopedic conditions
  Back pain
   Concerns: Impairment of mobility or respiratory
     function must be considered
  Aseptic necrosis
   Concerns: Aseptic necrosis may progress if
     decompression sickness affects the joint
Hematologic and rheumatologic conditions
  Sickle cell disease
    Concerns: Increased risk of decompression sickness
     may exist (theoretically), and sickle cell crisis may be
     incorrectly diagnosed as decompression sickness
  Polycythemia vera
  Hemophilia, impaired coagulation
    Concerns: Bleeding disorders could worsen the effects
     of barotrauma and exacerbate injury associated with
     decompression sickness
  Raynaud syndrome
    Concerns: Digit function may become impaired,
     hindering diving abilities
  Systemic lupus erythematosus
    Concerns: Pulmonary function and exercise tolerance
     should be evaluated prior to diving
Metabolic and endocrine conditions
 Hormonal excess or deficiency
 Renal insufficiency
   Concerns: Exercise tolerance must be proven
Metabolic and endocrine contraindications
 Insulin-dependent diabetes mellitus
   Concerns: Risk of potential rapid change in
    consciousness resulting in drowning
   Concerns: Risk to fetus of venous emboli formed
    during decompression is unknown
Mental health conditions
 Developmental delay
 History of drug or alcohol abuse
 History of psychosis
 Use of psychotropic medications
  Concerns: Patient must be mentally able to learn the
    information vital to diving safety and react appropriately
    as instructed
Mental health contraindications
 Active psychosis
 Untreated panic disorder
 Drug or alcohol abuse
  Concerns: Diver would be ill-equipped to handle
    stressful situations in diving
Otolaryngologic conditions
  Recurrent otitis externa
  Significant obstruction of external auditory canal
  Eustachian tube dysfunction
  Recurrent otitis media or sinusitis
  History of tympanic membrane perforation, tympanoplasty,
  Significant conductive or sensorineural hearing loss
  Facial nerve paralysis not associated with barotrauma
  History of round window rupture or inner ear barotrauma
    Concerns: Any of these conditions is likely to affect the
     ability to equalize pressure of sinuses or ears during
     ascent and descent and to increase the possibility of
  Full prosthedontic devices
  History of mid-face fractures
  Unhealed oral surgical sites
  Therapeutic radiation to the head or neck
  Temporomandibular joint dysfunction
    Concerns: These conditions may affect the manner in which
     the mouthpiece fits or is held or the way the mask fits
Otolaryngologic contraindications
  Monomeric tympanic membrane
  Open tympanic membrane perforation
  Tube myringotomy
  Ossicular chain surgery
  Inner ear surgery
  Facial nerve paralysis due to barotrauma
  Inner ear disease other than presbycusis
  Laryngectomy or partial laryngectomy
  Uncorrected laryngocele
  History of vestibular decompression sickness

di tayangkan ulang oleh dr.Erick Supondha (hyperbaric&Diving medicine Consultant) Jakarta Indonesia 021 99070050 ,http//:wwwindodivinghealth.com