This is an 11-month old female who experienced a 
near-drowning episode in a bathtub.  She had been 
placed in a bathtub approximately one-fourth full of 
water by her mother.  Her mother then left the child 
unattended and went to the restroom herself.  The child 
was behind the shower curtain.  The mother was gone 
approximately five minutes, and upon returning she 
found the child floating in the water face up without any 
respiratory effort.  She immediately grabbed the infant 
out of the bathtub, took her to the closest bed and 
attempted mouth-to-mouth resuscitation and some 
chest compressions.  She called 911 at that time.  
Immediately prior to the arrival of the ambulance, the 
mother noted spontaneous respirations.  Paramedics 
initiated positive pressure ventilation with a bag and 
mask apparatus.  Five minutes later, they arrived at the 
E.D. at which time the infant was noted to be crying.
     Exam:  VS T 36.5, P 120, R 45, BP 130/50, oxygen 
saturation while on supplemental oxygen (exact FiO2 
not known) and continuous positive airway pressure 
was 98%.  She was crying and active.  Head without 
signs of trauma.  Eyes normal.  Pupils equal and 
reactive.  Neck supple.  Heart regular.  Lungs 
spontaneous respirations with bilateral wheezing and 
rales.  Good air exchange.  Abdomen benign.  
Extremities with good pulses and perfusion.  No 
evidence of trauma.  Neuro:  active, crying, recognizes 
mother, interactive with mother.  Muscle tone good.

     Cardiac and pulse oximetry monitors were placed.  
A Foley catheter and nasogastric tube were placed.  
200cc of fluid was evacuated from the stomach.  Initial 
ABG:  pH 7.11, pCO2 27, pO2 140, bicarb 9.  
Electrolytes Na 125, K 4.0, Cl 92, bicarb 11.  Glucose 
245.  WBC 29,500 with 5% segs, 1% bands, 92% 
lymphs.  Hgb 12.3, Hct 35.8, platelets 394,000.  A chest 
radiograph was obtained.

View chest radiograph. 

     She was treated with sodium bicarbonate for 
metabolic acidosis, aerosolized albuterol for wheezing 
and furosemide for pulmonary edema.  The CXR shows 
small patchy basilar pulmonary infiltrates.
     She improves clinically and her chest radiograph is 
repeated two days later.

View follow-up chest radiograph.

     Her chest radiograph is now normal.


Discussion
     Drowning is defined as death within 24 hours as a 
result of submersion.  "Near drowning" refers to survival 
beyond 24 hours of the submersion episode.  The 
majority of accidents occur in swimming pools, ponds, 
lakes and bathtubs, with a peak incidence in children at 
less than 4 years of age and a second peak during the 
risk-taking age group of 15-24 years.  Among boys 
15-19 years, 38% of drownings are alcohol related. 

Pathophysiologically, the problems commonly seen in a 
submersion accident are:
     1.  Hypoxia
     2.  Hypothermia (EXCEPT when submersion occurs 
in water greater than body temperature)
     3.  Aspiration  (which can impair lung function and 
aggravate existing hypoxia after breathing is restored)

     Hypoxia is the primary problem.  The clinical 
manifestations of hypoxia are related to both the 
severity of hypoxia and the differing abilities of 
individual organs to tolerate hypoxia.  The brain cortex 
is the first to sustain irreversible damage.  The lower 
brain is next.  The lungs and heart can tolerate up to 
20-30 minutes of hypoxia and survive with appropriate 
post-rescue support. 
     Hypothermia:  This phenomenon explains the good 
outcome of victims who are submerged in icy waters for 
up to 45 minutes (and occasionally longer).  When 
submerged in icy cold water, the body temperature 
drops rapidly to a point where body activity and 
metabolism come to a virtual standstill.  If this standstill 
develops before available oxygen is completely used, 
the hypothermia confers a protective effect.  The 
remaining oxygen is used slowly and the body can 
survive submersion for a longer period of time before 
irreversible anoxic tissue damage develops.  In most 
other instances, (non-icy water drowning), the victim's 
temperature will drop too slowly to confer any protective 
effect.
     Aspiration:  Experience indicates that saltwater and 
freshwater aspiration do not produce significantly 
different respiratory injury patterns.  If large amounts 
are swallowed, hypo or hypernatremia may result from 
fresh or salt water submersions, respectively.  
Respiratory infection is possible, but antibiotics should 
be reserved for proven infection or  when grossly 
contaminated water is aspirated.

Clinical Manifestations
     In the first moments after rescue, the appearance of 
the child who has nearly drowned may range from 
apparently normal to apparently dead.  Body 
temperature is frequently low, even in temperate, 
warm-water environments.  Respiratory efforts may be 
absent, irregular, or labored, with pallor or cyanosis, 
retractions, grunting, and cough productive of pink, 
frothy material.  The lungs may be clear, or there may 
be rales, rhonchi and wheezing. Infection may develop 
as a consequence of aspirated mouth flora or 
organisms in stagnant water, but this is not usually 
important in the first 24 hours. 
     Respiratory function may improve spontaneously or 
deteriorate rapidly as pulmonary edema and small 
airway dysfunction worsens.
     Neurologic assessment may show an alert, normal 
child or any level of CNS compromise.  A child may 
display agitation and combative behavior, seizures, 
blunted responsiveness to the environment, or profound 
coma with stereotypic posturing or flaccid extremities.  
Superficial evidence of head trauma may be noted in a 
few children whose submersion episode is a secondary 
event.
     Conn and Baker devised a classification of 
submersion victims based on neurologic function since 
the CNS is the system most susceptible to damage 
from hypoxia.  The classification is useful for 3 reasons:  
1) it allows one to estimate the magnitude of the 
hypoxic insult; 2) it guides one in the selection of 
appropriate therapy; 3) it is highly predictive of patient 
outcome.
     They suggest the classification be made on patient 
findings within the first hour of retrieval from water.  
Patient classification by Conn and Baker divides the 
patient into categories A,B,C1-4.

Category:
     A:  Awake = Alert, fully conscious, minimal injury
     B:  Blunted = Obtunded to stuporous, normal central 
respiratory drive and other brain stem functions.
     C:  Comatose = Unarousable, abnormal brain stem 
function, abnormal central respiratory pattern, abnormal 
motor responses to painful stimuli.  May have seizures.  
Respiratory failure present.  Category C patients may 
be further subdivided:
     C1:  Decorticate.  Flexor posturing.  Cheyne-Stokes 
respirations
     C2:  Decerebrate.  Extensor posturing.  Central 
hyperventilation
     C3:  Flaccid.  Apneustic or cluster breathing
     C4:  Deceased?  Flaccid, apneic, no detectable 
circulation 

     Prediction of submersion victim outcome can be 
reduced to the following observation:   If the victim has 
not sustained a cardiac arrest, the potential for intact 
survival is good when appropriate resuscitation and 
prehospital care are provided.
     Patients in categories A and B almost uniformly do 
well with medical supportive therapy alone; intact 
survival is the rule.  A few category B patients develop 
respiratory failure severe enough to require mechanical 
ventilation, usually from aspiration.
     Patients in category C are in respiratory failure and 
require intensive therapy and monitoring.  Patient 
outcomes vary.  A very high percentage of category C1 
and C2 have normal outcomes.  A significant portion of 
C3 patients survive, but there is a substantial increase 
in their incidence of death or survival with 
anoxic-ischemic encephalopathy.  C4 patients do 
poorly.  The majority die or survive with profound 
anoxic-ischemic encephalopathy.

     Note that all submersion victims may be apneic 
when retrieved from the water since apnea is a 
common reflex when the face is immersed in cold water 
even if they have not sustained a cardiac arrest.  Since 
submersion victims with excellent prognosis may 
initially be found apneic, vigorous initial resuscitation 
measures should be attempted in all submersion 
victims.  Our patient was a Category A patient and did 
quite well as predicted.  The hypoxia was mild, and 
neurologic functioning was good.  Although she was felt 
to have aspirated, antibiotics are reserved for proven 
infection or when grossly contaminated water is 
aspirated.  For these reasons, this patient did not 
receive antibiotics.  She was observed for 24 hours, as 
there may be a pulmonary inflammatory response 
24-48 hours after the insult. 

Immediate evaluation:
     1.  Consider:  ABG, CBC, electrolytes, CXR.
     2.  Look for associated problems:  head, neck, other 
injuries; ingestion; possibility of a seizure (primary or 
resulting from trauma, hypoxia, hyponatremia).  Further 
tests after stabilization to be considered are CT scan of 
head, radiographs of the cervical spine, drug screen 
(eg., alcohol).

Management - Category A:
     1.  Supplemental oxygen.
     2.  Aerosolized beta-adrenergic agents for wheezing 
(albuterol).
     3.  Consider diuretic (furosemide) for pulmonary 
edema seen on CXR.
     4.  Sodium bicarbonate.  Give 1 meq/kg for pH 7.1 
or less.  As oxygenation improves, the acidosis will also 
resolve.
     5.  Drying and warming measures.
     6.  Consider NG tube placement to prevent 
aspiration and decompress the stomach.  Excessive 
stomach contents could elevate the diaphragm and 
restrict thoracic volume.

Management - Category B:
     1.  The above measures plus:
     2.  Intubation usually is not needed.
     3.  Electrolyte disturbances:  Hyponatremia may 
occur if large amounts of fresh water are swallowed.  
Hypernatremia may occur if salt water has been 
swallowed.
     4.  Start an IV at maintenance or slightly less than 
maintenance to prevent further pulmonary compromise.
     5.  Consider antibiotics for aspiration of 
contaminated contents.  Note that leukocytosis is a 
common stress response and is not indicative of 
infection.

Management - Category C: 
     1.  Apply the above measures plus:
     2.  Intubate and ventilate, as all C patients are 
comatose and have respiratory failure.  High distending 
pressures are usually required.
     3.  Monitor EKG for dysrhythmias.  Hypotension 
may also occur.
     4.  In addition to sodium abnormalities, hyperkalemia 
from metabolic acidosis may occur.
     5.  Treat seizures (primary or from electrolyte 
abnormalities, hypoxia, trauma).
     6.  Hyperglycemia is a stress response.  There is 
usually no need to treat this.
     7.  Leukocytosis, as mentioned, is an expected 
stress response.  Leukopenia can occur in profound 
hypoxia.  Consider antibiotics for aspiration of dirty 
water.

Prevention
     1.  Educate caretakers to potential submersion risks 
of bathtubs, water pails, pools, lakes, streams and the 
ocean.  Stress the need for close supervision by a 
responsible adult.
     2.  Neighborhood and private swimming pools 
should ideally be surrounded by a double barrier (eg., 
two sets of fences).  If a single barrier is used to 
surround the pool, the house should NOT be used as 
part of the barrier.
     3.  Encourage swimming lessons for all patients.  
However, water safety is not solely dependent on one's 
ability to swim.  An overall understanding of water 
safety to avoid risk-taking behavior is necessary to 
minimize risk.  For example, a 9-year old who can swim 
in a pool will easily drown in ocean surf or a rapidly 
flowing stream.
     4.  Encourage caretakers to learn CPR

References
     Aoki B.  Evaluation, stabilization, and transportation 
of the critically ill child.  Mosby Yearbook, 1992, 
pp.237-251.