Drowning

DROWNING

I.    INTRODUCTION

·       Drowning remains a significant public health concern, as it is a major cause of disability

and death, particularly in children. At least one third of survivors sustain moderate to severe neurologic sequelae.

·       It immediately threatens include effects on the central nervous and cardiovascular systems.

Thus, the most critical actions in the immediate management of drowning victims include prompt correction of hypoxemia and acidosis.

·       The degree of central nervous system (CNS) injury depends on the severity and duration of hypoxia. Post-hypoxic cerebral hypoperfusion may occur. Long-term effects of cerebral hypoxia, including vegetative survival are the most devastating.

II. DEFINITION

·       Drowning is death within 24 hours from suffocation by submersion in a liquid, normally

fresh water or sea water.

·       Near drowning is survival for more than 24 hours (even if temporary) from suffocation by submersion.

·       Secondary drowning is a nonspecific term for death after 24 hours from complications of submersion.

·       Immersion syndrome is sudden cardiac arrest on cold immersion.

III. EPIDEMIOLOGY

·       International statistics annually, approximately 150,000 deaths are reported worldwide

from drowning; the actual incidence is probably closer to 500,000.

·       It is the fourth most common injury after road traffic accidents in USA, self-inflicted injuries and violence. It is more common than war deaths.

·       In 2007, there were 3,443 fatal unintentional drowning (non-boating related) in the United

States statistics and an additional 496 drowning deaths in boating-related incidents.

·       Young children (< 5 years) and older adults were shown to be at highest risk.

IV. ETIOLOGY

Causes tend to vary with the person’s age.

·       Infants most often drown in bathtubs or buckets of water.

·       The children aged 1-5 years; residential swimming pools are the most common venue.

·       All age groups typically drown in ponds, lakes, rivers, and oceans: cervical spine injuries and head trauma, alcohol, drug ingestion, seizures, syncope, psychiatric illness, severe arthritis, neuromuscular disorder, diabetes mellitus, cardiac disease, hypothermia, hypoglycemia, which result from diving into water.

·       Drowning is a well-recognized complication of natural disasters, such as      hurricanes and earthquakes (Natural disasters).

·       Suicide

V.  PATHOPHYSIOLOGY

·       The most important contributory factors to morbidity and mortality from drowning are

hypoxemia and acidosis and the multiorgan effects of these processes. Central nervous system (CNS) damage may occur because of hypoxemia sustained during the drowning episode (primary injury) or may result from arrhythmias, ongoing pulmonary injury or multiorgan dysfunction (secondary injury), particularly with prolonged tissue hypoxia.

·       Two minutes after immersion, a child will lose consciousness.

·       Irreversible brain damage usually occurs after 4-6 minutes. Most children who survive are discovered within 2 minutes of submersion. Most children who die are found after 10 minutes.

·       85% of cases, asphyxia leads to relaxation of the airway before inspiratory efforts have ceased, and the lungs fill with water.

·       Pulmonary  oedema  is  a  common  insult.  Surfactant  loss  occurs,  producing  areas  of atelectasis and exudate can flood the alveoli. Further fluid shifts into the alveoli as pulmonary vessels constrict in response to the hypoxia and intravascular pressures rise. In addition,  foreign  body  aspiration,  laryngospasm  or  bronchospasm  may  worsen  the hypoxia.

·       Hypothermia, if it occurs, leads to a slowing of the metabolic rate but respiration is slowed even more so and hypoxia and hypercapnia develop. Prolonged hypoxia can lead to CNS and renal damage.

·       In addition, haemolysis occasionally occurs after freshwater near drowning. Freshwater drowning can be much faster than salt water drowning. Salt water has a higher osmolarity than plasma and tends to draw water out of the erythrocytes. Freshwater is hypotonic; water is drawn into erythrocytes that swell and burst releasing potassium. This induces hyperkalaemia that can stop the heart.

VI. CLINICAL PRESENTATION

·    History:

o Mechanism and duration of submersion.

o Type and temperature of water.

o Time to institution of CPR.

o Time to first spontaneous breath.

o Time to return of spontaneous cardiac output.

o Vomiting.

o Likelihood  of  associated  trauma,  other  precipitants  (arrhythmia,  myocardial

infarction, seizure, nonaccidental injury, etc.).

o All  aspects  of  the  drowning  episode  should  be  determined  including  the circumstances around the actual submersion.

·    A drowning victim may be classified initially into 1 of the following 4 groups:

o Asymptomatic

o Symptomatic

o Cardiopulmonary arrest

o Obviously dead

·    Symptomatic patients may exhibit the following:

o Altered vital signs (eg, hypothermia, tachycardia or bradycardia)

o Anxious appearance

o Cough

o Wheezing

o Hypothermia

o Vomiting, diarrhea, or both

o Tachypnea, dyspnea, or hypoxia: If dyspnea occurs, no matter how slight, the

patient is considered symptomatic

o Metabolic acidosis (may exist in asymptomatic patients as well)

o Altered level of consciousness, neurologic deficit

o Apnea

VII.     INVESTIGATIONS

·    ECG: note rate, rhythm, evidence of ischemia.

·    Bloods: arterial blood gas, electrolytes, renal function, glucose, osmolarity, alcohol level, FBC, coagulation screen, blood cultures.

·    Radiology: CXR, also C-Spine and possibly head CT scan if indicated.

·    Bronchoscopy is indicated if a foreign body is suspected.

VIII.    COMPLICTIONS

There are many possible complications:

·       Cardiac: cardiac arrest, bradycardia, myocardial infarction.

·       Pulmonary: pulmonary edema, pneumonia.

·       Neurological: stroke, cerebral hypoxia, cerebral oedema.

·       Renal: renal failure.

·       Haematological: haemolysis.

·       Metabolic: hyperkalaemia, acidosis.

·       Infections: pneumonia, septicaemia.

IX. TREATMENT

1.   The immediate action:

·    If a victim is in water and not breathing, resuscitation should be started by the rescuer whilst still in the water, as this improves outcome.

o Start Basic Life Support at the scene (see basic life support CPG).

o Remember the cervical spine may be injured.

o Initial resuscitation must focus on rapidly restoring oxygenation, ventilation, and

adequate circulation. The airway should be clear of vomits or foreign material,

which may cause obstruction or aspiration.

·    Do not be too eager to abandon resuscitation as hopeless, especially with co-existent hypothermia. Children can have remarkably good recovery after prolonged resuscitation with no neurological problems; however, the outcome is variable. It is not possible to predict at an early stage that will have good outcome and so aggressive resuscitation should be given to all.

·    Victims in cardiac arrest require aggressive or prolonged resuscitation and have a high risk of multi-organ system complications, major neurological morbidity or death.

·    All pediatric submersion victims probably should be hospitalized or observed for at least

6–12 hr, even if they are asymptomatic on presentation.

·    Several important modalities of treatment.

o Serial monitoring of vital signs (respiratory rate, heart rate, blood pressure, pulse oxymetry and temperature

o Rewarming measures.

o Oxygenation

o Intravenous fluids are required to improve circulation and perfusion.

o Nasogastric tube +/- urinary catheter.

o Instigate or continue resuscitation as required. Intubate if unconscious.

o Treat hypothermia,  hypoglycaemia, seizures, hypovolaemia, and hypotension, if

they occur.

o Both hyperglycemia and hypoglycemia are considered detrimental to the injured brain. Assessment of blood glucose should be obtained in the field and monitored frequently thereafter to maintain normoglycemia. If a child is found to be hypoglycemic, 2ml/kg intravenous dextrose 10% should be administered.

o Antibiotics should be given if fever develops or there is grossly contaminated aspirated water, and then targeted towards the likely pathogens. Pneumonia can be a major problem and even a fatal complication. (See antibiotics treated Pneumonia in CPG)

o Bronchospasm after downing: β2-agonist therapy (Salbutamol):

§    Salbutamol  inhalation  (Ventoline):  0.05  -  0.15  mg/kg/dose  of  solution

2.5mg/2.5ml

§    Initial  dose:  5mcg/kg  for  5min  followed  by  maintenance  dose  0.1  –

0.3mcg/kg/min IV

§    Salbutamol oral or IV: 0.15mg/kg/dose (max 4mg) 6 hourly

o Epinephrine IV: 0.01 mg/kg of 1: 10,000 solution given every 3–5 min as needed (usually the drug of choice, use with cardiopulmonary arrest, be required to augment myocardial function and support blood pressure). Epinephrine can be given intratracheally (ETT dose is 0.1–0.2 mg/kg of 1: 1,000 solution) if no intravenous access is available.

o The routine use of diuretics or corticosteroids for pulmonary edema or lung injury is not recommended.

o Dialysis for renal failure.

·    If the patient is awake and alert, observe for at least 6 hours. Pulmonary oedema may develop late (it usually develops within four hours).

·    Otherwise, the following may be needed: continuous positive airway pressure (CPAP), intubation and mechanical ventilation with high positive end expiratory pressure (PEEP), or even extracorporeal membrane oxygenation (ECMO) for severe pulmonary oedema (not available).

2.   Transfer

Patients must be treated in a facility capable of providing appropriate, age-related intensive care if

they exhibit any of the following:

·    Significant hypoxia that requires intubation

·    Worsening dyspnea with the potential for intubation

·    Evidence of hypoxic cerebral injury

·    Evidence of renal insufficiency

·    Evidence of hemolysis

·    Severe hypothermia requiring cardiopulmonary bypass

X.  PROGNOSIS

·    Patients who are alert or mildly obtunded at presentation have an excellent chance for full recovery.

·    Patients  who  are  comatose,  those  receiving  CPR  at  presentation  to  the  emergency department (ED) or those who have fixed and dilated pupils and no spontaneous respirations have a poor prognosis.

·    Pediatric studies indicate that mortality is at least 30% in children who require specialized treatment for drowning in the pediatric intensive care unit (PICU). Severe brain damage occurs in an additional 10-30%.

XI. PATIENT EDUCATION

·    Drowning of children is often called “silent death” or the “silent killer”. That is because children just sink and drown. It happens quickly, silently and without notice. There’s no

splashing to alert anyone that the child is in trouble."

·    Prevention is key, and community education is the key to prevention.

·    Toddlers  should  not  be allowed  near bathrooms  or buckets  of water  outside without immediate adult supervision.

·    Children should never swim alone or unsupervised, and children younger than 4 years and any children who are unable to swim should be accompanied by a responsible adult within arm's reach. Adults should know their own and their children's swimming limits.

·    Appropriate barriers must be used around pools, wading pools, and other water-containing devices at home.

·    Children should be taught safe conduct around water and during boating and jet- or water- skiing.

·    Use of alcohol or other recreational drugs is not appropriate when swimming or engaging in  other  water  sports,  as  well  as  when  operating  or  riding  in  motorized  watercraft.

Appropriate boating equipment should be used, including personal flotation devices, and all boaters must understand weather and water conditions.

·    Parents should seriously consider learning CPR and water safety training in case rescue and resuscitation are needed.

REFERENCES

1.     emedicine.medscape.com

2.     www.patient.co.uk : Drowning and Near Drowning

3.     Kliegman: Nelson Textbook of Pediatrics, 18th ed. copyright © 2007 Saunders, An Imprint of

Elsevier, chapter 73 –Drowning and Submersion Injury.

4.     http://ndpa.org/home/news/news-releases/2012/05/cdc-drowning-theleading-cause-of-injury- death-for-toddlers

5.     http://www.health.am/ab/more/a-silent-death/#ixzz26PJXALrQ

6.     WHO pocket book

Thanks