Drowning/submersion

Question 1

The term near drowning is no longer used; the term _____ is used to describe any event resulting in primary respiratory impairment from submersion or immersion in a liquid medium, whether it is fatal or not.

____ is a leading cause of morbidity.mortality in humans

Reports of drowning in veterinary patients are

primary pathophysiologic abnormality seen in drowning victims is

Treatment is aimed at

Answer 1

drowning

drowning

sparse

hypoxic tissue damage due to the inability to maintain adequate pulmonary gas exchange

neuroprotective therapy
cardiovascular support
oxygen-rich environment

Question 2

Prognosis in humans depends on

Answer 2

submersion time
cardiopulmonary resuscitation time
and severity of acidemia

Question 3

Drowning def.

Dry drowning describes 10%:

near drowning be abandoned as a term

submersion victim was proposed as an alternative to near-drowning victim by the American Heart Association and still is in use

Answer 3

process resulting in respiratory impairment from submersion or immersion in a liquid medium
-Liquid is present at the victim’s airway, preventing respiration of air. The victim may survive or die

-contrast to the definition in 2000, drowning was reserved for cases in which the victim died

cases in which liquid is not aspirated into the lungs, whereas wet drowning refers to aspiration of liquid. Victims of dry drowning often experience morbidity from laryngospasm, which results in the same hypoxemic and hypercarbic state seen in those who have aspirated liquid.

to describe victims of submersion injury who survive

Question 4

only ___ published reports of veterinary patients describing submersion injury

Answer 4

3

Question 5

third veterinary publication is a retrospective study describing fresh water submersion injury in 25 dogs and 3 cats. In this case series, ____ patients died, including all three cats, and the total mortality rate was ___%

Answer 5

10
36%
Respiratory failure was the most common cause of death

Question 6

Dry drowning ___%:
aspirate fluid into the lungs ___%:

MoA hypoxemia:

most submersion victims (about 85%) that survive are thought to have aspirated less

Answer 6

10
90
laryngospasm in which no aspiration
or aspiration = loss of surfactant that causes atelectasis and intrapulmonary shunt, pneumonia, ARDS

<22ml/kg

Question 7

fresh water versus saltwater:

was thought that the hypertonicity of aspirated saltwater would result in:

aspiration of fresh water was hypothesized to:

Studies did ____ these hypotheses
bc:

The most prominent pathologic feature in victims of both fresh water and saltwater submersion injury is:

Answer 7

osmotic gradient into the lungs, drawing plasma water into the pulmonary interstitium and alveolar spaces
- shift of plasma water would then result in hypernatremia and a decreased circulating blood volume and HYPOVOLEMIA

shift fluid out of the lung and into circulation, which would result in hypervolemia, hyponatremia, and dilution of other electrolytes

not support
the amount of aspirated water needed to cause these fluid shifts was far greater than the amount normally aspirated by drowning victims (far greater than 22ml/kg)

washout of SURFACTANT from the alveoli, causing atelectasis, intrapulmonary shunt, and global hypoxia, which may then result in tissue injury, neurologic damage, cardiovascular collapse, and death

Question 8

humans, about ___% of drowning victims experience severe neurologic effects

Answer 8

10

hypoxia-induced brain injury, and the severity of injury is primarily dependent on the duration of hypoxia

Question 9

Hypothermia may contribute to hypovolemia bc
hypothermia causes what…
bc…

Answer 9

inhibition of ADH and induction of diuresis

shunting of blood to core organs, which gives a perception of hypervolemia via arterial stretch receptors

Question 10

what reflex causes ice-cold water submersion injuries to have a more favorable outcome?

reflex mediated by the ____ nerve

Answer 10

dive reflex

• submersion in ice-cold water (<5° C [41° F]) within seconds after a victim’s face contacts cold water and before unconsciousness ensues
• reflex mediated by the trigeminal nerve sends impulses to the central nervous system that cause
• bradycardia, hypertension, and preferential shunting of blood to the cerebral and coronary circulations
• acts to protect the brain and heart from hypoxia-induced injury

Question 11

Hypothermia also causes a decrease in metabolic need, which protects the:

Hypothermia in patients in warm water, however, is a:

Answer 11

brain from injury
evidenced by good neurologic recovery in victims submerged in icy water, despite the initial presence of coma or other negative neurologic prognostic indicators

negative prognostic sign indicating poor peripheral perfusion and longer submersion times

Question 12

Tx:
O2/ventilation
Artificial surfactant has been used with:
Ab
Shock - fluids 
Neuroprotective

Answer 12

some success, and experimental therapies with liquid ventilation, inhaled nitric oxide, and intratracheal ventilation may be employe

• post BAL or prophylac.
• judicious
• permissive hypothermia, NaCl/mannitol if ICP

Question 13

three factors were associated with 100% mortality in human submersion victims younger than 20 years of age:

Additional factors associated with a poor prognosis:

Patients experiencing acute pulmonary edema had mortality rates ranging from

LOC: No deaths occurred in patients who arrived alert or depressed but responsive

Answer 13

(1) submersion duration longer than 25 minutes
(2) resuscitation duration longer than 25 minutes
(3) pulseless cardiac arrest on presentation

vtach or vfib (93% mortality)
fixed pupils (89% mortalitly)
severe acidosis (89% mortality)
and respiratory arrest in ED (89% mortality)

5% to 19%

Question 14

1 vetmed study:

Answer 14

mortality was reported as 36% in the study of 25 dogs and 3 cats with submersion injury, with all 3 cats included in the nonsurvivors