Travel Reference
In-Depth Information
Table 28-2
Sequence of Drowning
A unique situation occurs with drowning in the Dead Sea, which has an unusually large
solute load. Deaths result from pulmonary complications as well as the arrhythmias in-
duced bysevere imbalances ofsodium, calcium, and magnesium. The mortality rate in one
study of Dead Sea drowning was 50 percent.
Freshwater Drowning
Aspirated fresh water washes out surfactant, which alters surface tension in the lungs,
resulting in alveolar collapse and instability. The capillary and alveolar membrane damage
results in fluid leakage and subsequent pulmonary edema. Aslittle as 1to 3ml/kgofaspir-
ated water (approximately 3 to 8 ounces for a 175-pound individual) has been associated
with significant falls in arterial oxygen. Fresh water aspirated into the lungs is rapidly ab-
sorbed into the circulation; however, the volumes are seldom large enough to cause signi-
ficant changes in electrolyte concentration and increases in venous pressure are transitory.
Saltwater Drowning
Seawater is hypertonic; it has three to four times greater osmolality than blood. The salt
(sodium chloride) concentration in seawater is approximately 3.5 percent; blood has a so-
dium chloride concentration of 0.9 percent. This hypertonicity is irritating to the termin-
al bronchioles and produces an osmotic gradient resulting in alveolar fluid accumulation
(pulmonary edema). Pulmonary edema is compounded by injury of the alveolar-capillary
membrane produced by the hypertonic saline.
Increased concentrations of magnesium have also been associated with seawater aspira-
tion and may contribute to low blood pressure (hypotension), neuromuscular malfunction,
respiratory depression, and cardiac abnormalities.
In spite of these differences, the resuscitative techniques and subsequent care for indi-
viduals who have drowned in saltwater usually are not significantly different from the care
of individuals who have drowned in fresh water.
COLD WATER DROWNING
Few rescue stories arouse as much excitement as the “miraculous survival” of individuals
whoweresubmersedforlongperiodsandlived.Mosthavebeensubmergedinwatercolder
than 50°F (10°C) for less than thirty minutes:
Search WWH ::
Custom Search