CEREBRAL ARTERIAL GAS EMBOLISM

Air embolism

• An air embolism, or more generally gas embolism, is a medical condition caused by gas bubbles in the bloodstream (embolism in a medical context refers to any large moving mass or defect in the blood stream).

• Death may occur if a large bubble of gas becomes lodged in the heart, stopping blood from flowing from the right ventricle to the lungs . However, the amount of gas necessary for this to happen is quite variable, and also depends on a number of other factors, such as body position.

ARTERIAL GAS EMBOLISM

Gas embolism into an artery, termed arterial gas embolism, or AGE, is a more serious matter than in a vein, since a gas bubble in an artery may directly cause stoppage of blood flow to an area fed by the artery. The symptoms of AGE depend on the area of blood flow, and may be those of stroke or heart attack if the brain or heart, respectively, are affected.

ARTERIAL GAS EMBOLISM

Arterial gas embolism (AGE) is usually the result of some injury to the lungs causing air bubbles to "leak" into the bloodstream.

(From Wikipedia, the free encyclopedia)

Mechanism of injury

If a diver ascends without exhaling, the gas in the lungs will expand due to the reduced pressure surrounding the lungs and may rupture lung tissue. This is pulmonary barotrauma which releases gas bubbles into the arterial circulation. This will cause the bubbles to be circulated through the body via the bloodstream. If the bubbles reach the brain and damage it, this is a particularly serious type of arterial gas embolism termed CAGE (Cerebral Arterial Gas Embolism). The symptoms of CAGE are those of stroke.

A person suffering from AGE may surface unconscious. This does not mean that any person who is conscious on surfacing is excluded from the possibility of AGE.

Pathogenesis

Air embolism can occur whenever a blood vessel is open and a pressure gradient exists favoring entry of gas. Because the pressure in most arteries and veins is greater than atmospheric pressure, an air embolus does not always happen when a blood vessel is injured. In the veins above the heart, such as in the head and neck, the pressure is less than atmospheric and an injury may let air in.

When air enters the veins, it travels to the right side of the heart, and then to the lungs. This can cause the vessels of the lung to constrict, raising the pressure in the right side of the heart. If the pressure rises high enough in a patient who is one of the 20% to 30% of the population with a patent foramen ovale, the gas bubble can then travel to the left side of the heart, and on to the brain or coronary arteries. Such bubbles are responsible for the most serious of gas embolic symptoms.

Trauma to the lung can also cause an air embolism. This may happen after a patient is placed on a ventilator and air is forced into an injured vein or artery, causing sudden death. Breath-holding while ascending from scuba diving may also force lung air into pulmonary arteries or veins in a similar manner, due to the pressure difference.

Arterial gas embolism (AGE) is another disorder in which bubble formation may occur in the vascular system.[18] The bubbles in AGE originate not from supersaturation of gases in the blood and tissues but from rupture of the alveoli due to the barotrauma of ascent. The bubbles enter the pulmonary venous system and are carried to the heart and arterial systemic circulation.

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Pathophysiology

The working rules is : Any diver who has obtained a breath of compressed gas from any source at depth who surfaces and remains unconscious or losses consciousness or has any neurological deficits within 10 minutes of reaching the surface must be assumed to be suffering from AGE

PULMONARY OVERINFLATION

RUPTUR OF ALVEOLI

PULMONARY INTERSTiTIAL EMPHYSEMA

ARTERIAL GASEMBOLISM

PNEUMOTHORAX

MEDIASTENALEMPHYSEMA

CEREBRAL GASEMBOLISM

CORONARY GASEMBOLISM

SUBCUTANEOUSEMPHYSEMA

PNEUMO-PERICARDIUM

Systemic symptoms

As might be expected, most symptoms from this disorder are localized to the cerebral circulation (Fig. 4), with occasional embolization to the coronary arteries causing cardiac arrest. Classically, the presentation is that of sudden onset of unconsciousness within minutes of reaching the surface after a dive--there having been some reason why the diver ascended with his glottis closed (unconsciousness, panic, dry suit blowup, loss of weights, malfunction of buoyancy compensator). Other possible presentations include hemispheric motor and/or sensory deficits, confusion and convulsion. Peripheral nerve changes and musculoskeletal pain are not part of the symptom complex of AGE.

Perlu untuk diperhatikan :Gas embolism and decompression sickness (DCS) may be difficult to distinguish, as they may have similar symptoms, especially in the central nervous system. The treatment for both is the same, because they are both the result of gas bubbles in the body. In a diving context, the two are often called decompression illnes (DCI).

Differentiating between AGE and DCS

AGE - (1) Any type of dive can cause AGE, (2) the onset is immediate (<10-120 min), and (3) neurologic deficits manifest in only the brain.

DCS - (1) The dive must be of sufficient duration to saturate tissues, (2) the onset is latent (0-36 h), and (3) neurologic deficits manifest in spinal cord and brain.

Treatment

Management is generally similar to that of DCS--recompression and HBO are indicated in all cases as quickly as possible.[22]

Specifi cs: Recompression Treatment of Gas Embolism

In contrast to the treatment of decompression sickness, one should not delay for diagnostic work-up or extensive clinical evaluation. Instead, the first question is whether to use Treatment Table 6A or 6 (Tables VII , VI ). If there is a delay greater than 4 hours, Treatment Table 6 ( Table VI ) should be used initially and then proceed to 6A ( Table VII ) depending on the clinical response. Treatment Table 6A ( Table VII ) allows for rapid compression to 165 feet and is used for major air embolisms. If such a chamber is not available, then one should use a 3 ATA chamber.

For those patients not responding to Navy Table 6 ( Table VI ), other choices are available: US Navy Table Treatment 4 ( Table VIII ) or the Comex Table, which prescribes 30 minutes breathing 50/50 : O2/N2 mix at 100 feet. Unproven treatment schedules should be avoided, but extensions to the tables are not experimental and should be used as necessary.

PROGNOSIS

Rapid treatment is also crucial in the face of AGE. Those with AGE who reach recompression within 5 minutes have a death rate of only 5%. This rapid treatment also results in little morbidity. However, when AGE recompression is delayed 5 hours, the mortality rate approaches 10%. More than 50% of the survivors experience residual signs.

AIR CRAFT TRANSPORTATION

An important issue is transport of the patient to the closest hyperbaric facility. This is frequently accomplished by land transport; however, air transportation is occasionally required. Helicopter transport requires the pilot to maintain an altitude of less than 500 ft (152 m) above the departure point (which could be more than 500 ft above sea level depending on the dive location). This can be difficult when there are mountains to traverse in flight. An effort should also be made to minimize the transport time. Fixed-wing transport should be limited to aircraft that can maintain cabin pressure at normal surface pressure of 1 atm (eg, Lear Jet, Cessna Citation, military C-130 Hercules).

TERIMA KASIH

TERIMA KASIH

ANJURAN KEPADA PASIEN

• DCS I : PASIEN MASIH BOLEH MENYELAM SETELAH 6 BULAN.

• DCS II : PASIEN TIDAK BOLEH MENYELAM LAGI

BAROTRAUMA PARU

BAROTRAUMA PARU TURUN,DESCENT [SQUEESE PARU]

PADA PENYELAM TAHAN NAFAS (BREATHOLD DIVE)

SQUEESE PARU

1. PENYEBAB, KENAIKAN TEKANAN TIDAK DIIKUTI KESTABILAN VOLUM PARU

2. TERJADI PADA PENYELAM TAHAN NAFAS

3. VOLUME PARU DIKEDALAMAN MENDEKATI VOLUME RESIDU PARU

4. SERING TERJADI PADA PENYELAM DENGAN KAPASITAS VOLUME PARU YANG KECIL

5. BERLANJUT SEBAGAI ATELEKTASIS PARU

SQUEESE PARU

BAROTRAUMA PARU BAROTRAUMA PARU NAIKPULMONARY OVERINFLATION

1. PENYEBAB, PENURUNAN TEKANAN TIDAK DIIKUTI PENGURANGAN VOLUM PARU

2. TERJADI PADA PENYELAM DENGAN ALAT

3. VOLUME PARU EKSPANSI SEWAKTU MENUJU KE PERMUKAAN/DIPERMUKAAN

4. SERING TERJADI PADA KEDARURATAN PENYELAM ATAU LATIHAN ESCAPE

5. BERLANJUT SEBAGAI EMBOLI UDARA

INITIAL TREATMENT 1. MAINTAIN AN ADEQUATE AIRWAY,VENTILATION 2. CORRECTION HYPOTENSION 3. ADMINISTER 100 % O2 4. ADMINISTER A BOLUS OF DEXAMETHASONE

DEFINITIVE TREATMENT RECOMPRESSION THERAPY

ADJUVANT THERAPY 1. STEROIDS 2. FLUIDS 3. HEMODYNAMIC SUPPORT 4. VENTILATION

BAROTRAUMA PARU NAIKPULMONARY OVERINFLATION