DIVING EMERGENCIES Dr. Ülkümen Rodoplu V. Mediterranean Emergency Medicine Congress September 09, Valencia

Who is the protector of divers ?

Oceanus

Drunken Dionysus

The second biggest in the World

St. Pierre

Introduction SCUBA diving accidents are fairly uncommon. Inexperienced divers have a higher incident rate of injury. Emergencies can occur on the surface, one meter of water, or at any depth. More serious emergencies usually follow a dive.

History of Scuba Henry Fleuss invents a self contained underwater breathing unit Yves Le Prieur releases a more advanced breathing unit Jacques-Yves Cousteau and Emile Gagnan design and test the first Aqua-Lung.

Introduction SCUBA, self-contained underwater breathing apparatus. New advances. Equipment improvements. Behavior of gases and pressure changes during descent and ascent. Clinical manifestations seen during diving or up to 24 h after it.

Regular breathing makes use of differences in air pressure The water above a diver increases the atmospheric pressure. Therefore, Air must be pressurized to be able to breathe at a pressure of more than one Atmosphere (air pressure at sea level). (This is also why you have to pop your ears as you descend.) Underwater breathing

Main Pathologies Barotrauma Decompression ilness Pulmonary edema Pharmacological and toxic effects of increased partial pressures of gases

Physical Principles of Pressure Density of the water can be equated to pressure, which is defined as the weight or force acting upon a unit area. Fresh water exerts a pressure of 62.4 pounds over an area of one square foot (salt water is 64 pounds). Stated as pounds per square inch (psi) At sea level humans live in an atmosphere of air, or a mixture of gases, and they exert a pressure of 14.7 psi.

Gas Laws Boyle’s Law “ For any gas at a constant temperature, the volume of the gas will vary inversely with the pressure, and the density of the gas will very directly with the pressure.” If T= constant, then V  1/P and Density  P (Never hold your breath!)

Charles’s Law For any gas at a constant pressure, the volume of the gas will very directly with the absolute temperature. If P= constant, then V  T Or For any gas at a constant volume, the pressure of the gas will vary with the absolute temperature. If V= constant, then P  T (keep tanks cool and don’t fill them too fast.)

Henry’s Law The amount of any given gas will dissolve in a liquid at a given temperature is proportional to the partial pressure of that gas in equilibrium with the liquid and the solubility coefficient of the gas in the particular liquid. An increase in pressure will increase absorption (Oxygen in your blood dissolves at a given pressure.)

Henry's Law The amount of any given gas that will dissolve in a liquid at a given temperature is a function of the partial pressure of that gas in contact with the liquid... Gas molecules will dissolve into the blood in proportion to the partial pressure of that gas in the lungs.

Henry’s Law At sea level, the dissolved gases in the blood and tissues are in proportion to the partial pressures of the gases in the person's lungs at the surface. As the diver descends,the ambient pressure increases, and therefore the pressure of the gas inside the lungs increases.

Injuries During Descent Barotrauma, commonly called the “squeeze” becomes a concern during the descent. Unable to equilibrate the pressure between the nasopharynx and the middle ear through the eustachian tube can result in middle ear pain, Ringing in the ears, dizziness, hearing loss. In severe cases, rupture of the ear drum can occur.

Injuries During Descent Similar lack of equilibration can occur in the sinuses, producing severe frontal headaches or pain beneath the eye in the maxillary sinuses.

Injuries at the Bottom Nitrogen narcosis. Due to nitrogen’s effect on cerebral function. Diver may appear to be intoxicated and may take unnecessary risks.

Nitrogen Narcosis Rapture of the deep, the martini effect. Direct toxic effect of high nitrogen pressure on nerve conduction. Variable sensation but always depth-related. Some divers experience no narcotic effect at depths up to 40 m. whereas others feel some effect at around 25 m. The diver may feel and act totally drunk. Takes the regulator out of their mouth and hands it to a fish !

Injuries During Ascent Serious and life-threatening emergencies occur during the ascent. Most serious barotrauma during ascent is injury to the lung. (from 1m. of water to a deep dive). Injury results from divers holding their breath during ascent.

Injuries During Ascent During the ascent the air in the lung begins to expand. If not exhaled the alveoli may rupture. Resulting in an air embolism. May also include mediastinal and subcutaneous emphysema due to diffusion of the gas through the lung into the mediastinum and neck. Pneumothorax is possible if the alveoli rupture into the pleural cavity.

General Assessment of Diving Emergencies Early assessment and treatment. Must develop the diving history or profile. This includes: 1.Time at which the signs and symptoms occurred 2.Type of breathing apparatus utilized 3.Type of hypothermia protective garment worn

Diving History 4.Parameters of the dive: * Depth of dive * Number of dives * Duration of dive 5.Aircraft travel following a dive 6.Rate of ascent 7.Associated panic forcing rapid ascent 8.Experience of the diver 9.Properly functioning depth gauge

Diving History 10.Previous medical diseases 11.Old injuries 12.Previous episodes of decompression illness 13.Use of medication 14.Use of alcohol This history will assist in determining if the diver has incurred a pressure disorder

Pressure Disorders Decompression Sickness (Bends) Condition that develops in divers subjected to rapid reduction of air pressure after ascending to the surface following exposure to compressed air.

General factors relating to development Cold water dives Diving in rough water Overstaying time at given dive depth Dive at 25 m. or greater Rapid ascent – panic, inexperience, unfamiliarity with equipment. Flying after diving – 24 hour wait is recommended. Driving to high altitude.

Individual factors relating to development Age – older individuals. Obesity. Fatigue – lack of sleep prior to dive Alcohol – consumption prior or after dive History of other medical problems.

Pathophysiology Results as nitrogen bubbles enter the tissue spaces and small blood vessels. Symptoms present when a diver rapidly ascends after being exposed to a depth of 10 m. or more for a time sufficient enough to allow the body’s tissues to be saturated with nitrogen. Effects on the body can be direct or indirect

Direct Effects Intravascular: blood flow will be decreased, leading to ischemia or infarct. Extravascular: tissues will be displaced, which further results in pressure on neutral tissue Audiovestibular: air can diffuse into the audiovestibular system, causing vertigo

Indirect Effects Surface of air emboli may initiate platelet aggregation and intravascular coagulation Extravascular plasma loss may lead to edema Electrolyte imbalances may occur Lipid emboli are released

Presentation Decompression sickness divided into two types based on the presenting signs and symptoms.

Type I Usually referred to as the “bends”. Patient experiences pain (joints) Caused by expansion of gases present in the joint space. Skin manifestations usually consist only of pruritus (itch). Rash, spotted pallor, cyanosis, or pitting edema may occur.

Type I Treatment mainly consists of oxygen inhalation but could require recompression. Prognosis is usually good.

Type II Broad spectrum of complaints and could include symptoms of Type I Paresthesias* Paralysis Dizziness or vertigo* Headache Nausea* Dyspnea Auditory disturbances* Chest Pain Vestibular disturbances* Loss of consciousness * Hemoptysis

Type III Decompression Sickness Pulmonary complications of decompression sickness, referred to as “the chokes” are extremely serious. Combination of AGE and DCS with neurologic symptoms.

General Symptoms of Decompression Sickness Extreme fatigue Joint pain Headache Lower abdominal pain Chest pain Urinary dysfunction Vertigo and ataxia Pruritus Back pain Priapism Paresthesias Paralysis Dysarthria Frothy, reddish sputum Dyspnea

Prehospital Management Patients usually seek medical attention within 12 hours of ascent from a dive. S&S developing more than 36 hours after a dive cannot reasonably be attributed to decompression sickness. Oxygen therapy and possible recompression.

Prehospital Management Assess ABCs CPR if required Oxygen (NRM or intubate if necessary) Left lateral Trendelenburg position if possible Protect from excessive heat, cold, wetness, or noxious fumes Fruit juices or balanced salt solutions if conscious IV’s (crystalloid of choice) CNS involvement administer decadron, heparin, valium If flown, lowest altitude possible and take diving equipment with you for analysis Early recompression treatment for all forms.

Pulmonary Overpressure Accidents Lung overinflation due to rapid ascent is common cause of diving emergencies. Air expansion on ascent can rupture the alveolar membranes. Resulting in hemorrhage, reduced oxygen and carbon dioxide transport, and capillary and alveolar inflammation. Air can escape and cause pneumothorax and tension pneumothorax, subcutaneous emphysema, or pneumomediastinum

Air Embolism Any person using SCUBA equipment presenting with neurologic deficits during or immediately after ascent, should be suspected of air embolism Form of barotrauma of ascent. Very serious condition in which air bubbles enter the circulatory system through rupture of small pulmonary vessels. Air can also be trapped in blebs, air pockets, within the pulmonary tissue

Air Embolism Bubbles can be transported to the heart and the brain, where they may lodge and obstruct blood flow, causing ischemia and possibly infarct. Rapid and dramatic onset. Sharp, tearing pain. Paralysis (frequently hemiplegia). Cardiac and pulmonary collapse. Unequal pupils. Wide pulse pressure

Air Embolism Prehospital Management 1.Assess ABCs. 2.Administer oxygen by NRM. 3.Place patient in left lateral Trendelenburg position. 4.Monitor vital signs frequently. 5.Administer IV fluids. 6.Corticosteroid. 7.Transport to recompression chamber ASAP.

Pneumomediastinum Release of gas through the visceral pleura into the mediastinum and pericardial sac. Substernal chest pain. Irregular pulse. Abnormal heart sounds. Reduced blood pressure/narrowing pulse pressure. Change in voice. May or may not be evidence of cyanosis

Pneumomediastinum Prehospital Management 1.Administration of high-concentration oxygen via nonrebreathing face mask 2.Start IV 3.Transport Treatment generally ranges from observation to recompression

What is Hyperbaric Oxygen Therapy? Entirely enclosed chamber Breathing oxygen, greater than one atmosphere

What is Hyperbaric Oxygen Therapy? Mechanical effect of increased pressure: - Any free gas trapped in the body will decrease in volume as the pressure on it increases - Successfully applied to air embolism and decompression sickness

Final Words Emergencies can occur on the surface, one meter of water, or at any depth. More serious emergencies usually follow a dive. Be sure you know the Hyperbaric Oxygen Therapy facilities in your community.