Near Drowning Flashcards Preview

Pathophysiology 2 > Near Drowning > Flashcards

Flashcards in Near Drowning Deck (46)
Loading flashcards...
1
Q

Near Drowning

Epidemiology

A

Big issue especially with kids (<4 yr of age)

WHO: Drowning is the third leading cause of death by unintentional injury worldwide.

Children can drown in just a few cm of water

2
Q

New Drowning Outcome According to WHO

A

Death

With Morbidity

With no morbidity

3
Q

Drowning Definition

A

Suffocation and death due to submersion in a liquid

4
Q

Near Drowning Definition

A

When a victim survives a liquid submersion, at least temporarily

5
Q

Dry Drowning Definition

A

As soon as fluid is inhaled the bronchi constricts in response to a parasympathetic mediated reflex

Due to involuntary laryngospasm liquid does not enter the lungs

10-20% of victims maintain the laryngospasm until cardiac arrest

Have lidocaine ready for the laryngospasm

Lungs of near-dry drowning victims are normal

6
Q

Wet Drowning Definition

A

As oxygen levels fall the glottis relaxes and the liquid enters the lungs

When there is fluid in the lungs it will interfere with surfactant ability and look similar to ARDS

7
Q

Aquatic Distress

A

The “classic” picture of drowning

Often, but not always, precedes drowning

Visible, active/violent/abrupt movements

This will only last 20-60 seconds

8
Q

Instictive Drowning Response

A
  • The more typical picture of drowning
  • Behaviors instinctively taken by someone drowning (or close to drowning)
  • Noiseless and subtle behaviorsthat are instinctive
    • Will remain in the same position and extend arms out to the sides
    • Mouth is sinking below and reappearing above the water
    • Most drowning victims cannot yell for help because they are having trouble breathing
    • Young children will struggle less than adults and can look like they are doing the dog paddle in the water
9
Q

Sequence of Drowning

A

Panic and violent struggle to return to the surface

Period of calmness and apnea

Swallowing of large amounts of fluid, followed by vomiting

Gasping inspirations and aspirations

Convulsion

Coma

Death

10
Q

SALT WATER VS FRESH WATER

A
  • Pathologic changes in the lungs essentially the same
    • Reduction in pulmonary surfactant, alveolar injury, atelectasis, and pulmonary edema
  • Salt water near-drowning victims often have more electrolyte disturbances
    • Also if you swallow enough fresh water you will have electrolyte imbalance
11
Q

Cold Vs. Warm Water

A

> 20 °C is warm; < 20°C cold

Cold water immersion will stimulate the diving reflex in young children (apnea, bradycardia, core-saving vasoconstriction)

Because water is an excellent conductor of body heat (cold water can cool the body 25 times faster than air in the same temperature), because evaporation further reduces an individual’s body heat and produces hypothermia

12
Q

Clean Vs. Unclean Water

A

E.g. swamp, pond, sewage, mud, chlorine pool

May have aspirated pathogens and solid material

Risk of developing pneumonia and ARDS is much higher

13
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Age

A

The younger the better outcome

Younger people tend to crash hard but easier to bring back

14
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Submersion Time

A

The shorter, the better

60 min is the upper limit in cold water submersion

15
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Water Temperature

A

The colder the better

Range 27-70oF

16
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Water Quality

A

The cleaner the better

17
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Other Injuries

A

None Serious

18
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Amount of Struggle

A

Less struggle the better

19
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

CPR Quality

A

Good CPR technique increases survival rate

20
Q

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Suicidal Intent

A

Lower survival rate among victims who attempted suicide than victims of accidental submersion

21
Q

Pathophysiology

A

This is in regards to wet near-drownings, as dry near drownings will have normal lungs

  • Laryngospasm
  • Noncardiogenic pulmonary edema
  • Decreased surfactant
  • Alveolar shrinkage and atelectasis
    • Due to the pulmonary edema
  • Alveolar consolidation
  • Bronchospasm
  • Pulmonary hypertension
    • Secondary hypoxemia or inflammatory mediator release
22
Q

most important contributory factors to morbidity and mortality from drowning

A

The most important contributory factors to morbidity and mortality from drowning are hypoxemia and acidosis and the multiorgan effects of these processes.

23
Q

Central Nervous System Damage

A
  • May be caused by
    • A primary injury (prolonged hypoxemia during episode)
    • Secondary causes (reperfusion injury, cerebral edema, seizures, arrhythmias)
    • May be a concomitant head or spinal cord injury
  • CNS injury remains the major determinant of subsequent survival and long-term morbidity in cases of drowning. Two minutes after immersion, a child will lose consciousness. Irreversible brain damage usually occurs after 4-6 minutes.
24
Q

The Heart and Near Drowning

A

Can result in myocardial dysfunction

25
Q

Blood Volume Changes and Near Drowning

A

If more than 11 mL/kg of water is aspirated

Hypovolemia can result due to the fluid losses from increased capillary permeability

26
Q

Electroylte Changes and Near Drowning

A

If more than 22 mL/kg of water is aspirated

27
Q

CLINICAL MANIFESTATIONS

A

Apnea or tachypnea

Increased HR and BP

Cyanosis

Cough with frothy, white or pink sputum

Crackles on auscultation

Restrictive lung pathophysiology

28
Q

ABG

A

Resp acidosis with hypoxemia

Metabolic acidosis if lactic acid present

Lactic Acid may be present if there is a lot of struggling and they used a lot of energy

29
Q

CXR

A

Initial CXR may be normal; may deteriorate within the first 48-72 h

Pulmonary edema and atelectasis

Fluffy infiltrates; air bronchograms

30
Q

Oxygenation Indices

Qs/Qt

A

Increased

Because the alveoli are filled with fluid

31
Q

Oxygenation Indices

DO2

A

Decreased

32
Q

Oxygenation Indices

VO2

A

Normal

33
Q

Oxygenation Indices

C(a-v)O2

A

Normal

34
Q

Oxygenation Indices

O2ER

A

Increased

35
Q

Oxygenation Indices

SvO2

A

Decreased

36
Q

PRE-HOSPITAL MANAGEMENT

A

Conserve heat/maintain body temperature

Remove wet clothes, cover

All drowning victims should get 100% O2

If in cardiac arrest: CPR; establish an airway

37
Q

HOSPITAL MANAGEMENT For the Spontaneously Breathing Patient

A

Intubation and ventilation if PaO2 < 60 mmHg on FiO2 of 0.50 or higher, or if respiratory acidosis present (<7.25)

NIPPV can be considered prior to intubation if patient is awake and alert

38
Q

Hospital Management

Mechanical Ventilaition

A

ARDS/lung protective strategy with permissive hypercapnia as necessary

39
Q

Hospital Management

A

Bronchodilators (If bronchospasm is present)

Manage Electroyle imbalance

Surfactant Therapy

Permissive Hypothermia

40
Q

Hospital Management

Warming of the Patient

A

Nearly all drowning victims are hypothermic to some degree

Warm IV solutions, heated lavage, Active humidity on the ventilator

Heating blankets (Bear hugger)

(Rare) Cardiopulmonary bypass and blood warming

**Rewarming may be balanced by a goal of permissive hypothermia for neuroprotection…more research needed (Especially in victims that required CPR)

Resuscitation should not end even if patient does not respond until a close approximation of normal body temperature is reached

41
Q

Hospital Management

Treatment for Fluid Depletion

A

Fluids, possibly inotropes

42
Q

Hospital Management

Bronchoscopy

A

To remove foreign material if present (debris, vomit)

43
Q

Noncardiogenic Pulmonary Edema

A

Due to increased permeability of the membrane fluid from the pulmonary capillaries will move into the perivascular spaces, peribronchial space, alveoli, bronchioles, and bronchi (Interstitial edema)

As a consequence of fluid movement, the alveolar wall and interstitial space swell, pulmonary surfactant concentration will decrease, and surface tension will increase

Excessive fluid in the interstitial space causes lympathetic vessels to dilate and lymph flow to increase

44
Q

Tachypnea in Near Drowning

A

Stimulation of peripheral chemoreceptors (hypoxemia)

Decreased lung compliance- Increased ventilatory rate relationship

Stimulation of J receptors

Anxiety (conscious patient)

45
Q

Cough with frothy, white or pink sputum in Near Drowning

A

the fluid that accumulates in the tracheobronchial tree is churned into a frothy white (sometimes blood tinged) sputum as a result of air moving into and out of the lungs (generally by means of mechanical ventilation)

46
Q

What Happends to Virutally Every Near Drowning Patient

A

Virtually every near drowning victim suffers from hypoxemia, hypercapnia, and acidosis (acute ventilatory failure)

Hypoxemia will generally persists after aspiration of fluids in the airway (wet drowning) because alveolar capillary damage and continued intrapulmonary shunting

The degree of hypoxemia is directly related to the amount of alveolar capillary damage