Overview
Definition:
Drowning is the process of experiencing respiratory impairment from submersion or immersion in liquid
Hypothermia occurs when the body loses heat faster than it produces it, leading to a dangerously low core body temperature
Acute Respiratory Distress Syndrome (ARDS) is a severe lung injury characterized by diffuse alveolar damage, non-cardiogenic pulmonary edema, and refractory hypoxemia, often a consequence of drowning.
Epidemiology:
Drowning is a leading cause of unintentional injury death worldwide, particularly in children
In India, drowning remains a significant public health concern, with pediatric cases being disproportionately high
Factors such as access to water bodies, lack of supervision, and socioeconomic status play a role
Hypothermia is common in cold-water drownings and can paradoxically offer some neuroprotective effects.
Clinical Significance:
Effective management of pediatric drowning requires immediate recognition, prompt resuscitation, and comprehensive supportive care addressing both hypoxemia and hypothermia
ARDS is a common and serious complication, necessitating advanced respiratory support
Understanding these aspects is crucial for pediatric residents preparing for high-stakes examinations like DNB and NEET SS, as these scenarios test critical decision-making skills under pressure.
Clinical Presentation
Symptoms:
Unresponsiveness
Apnea or gasping
Cyanosis
Bradycardia
Hypotension
Hypothermia (cold skin, decreased level of consciousness)
Coughing, choking, or vomiting immediately after extrication
Respiratory distress or failure.
Signs:
Altered mental status ranging from lethargy to coma
Respiratory distress: tachypnea, retractions, grunting, wheezing, decreased breath sounds
Cardiovascular instability: bradycardia, hypotension, weak pulses
Skin may be pale, clammy, and cold (in hypothermia)
Laryngospasm or frothing at the mouth.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the event of submersion/immersion and subsequent respiratory compromise
ARDS diagnosis in drowning survivors follows established criteria, often including: acute onset of respiratory symptoms, bilateral opacities on chest imaging not fully explained by effusions, lobar or lung collapse, or nodules, PaO2/FiO2 ratio <300 mm Hg, and not fully explained by cardiac failure or fluid overload.
Diagnostic Approach
History Taking:
Crucial elements include the circumstances of the drowning (freshwater vs
saltwater, duration of submersion, water temperature, witnessed vs
unwitnessed), any initial resuscitation efforts by bystanders, the patient's baseline health status, and any pre-existing medical conditions
Red flags include prolonged submersion, witnessed asystole, or significant hypothermia.
Physical Examination:
A rapid and systematic assessment is vital: Airway (clearance of debris, need for suctioning), Breathing (rate, effort, auscultation for breath sounds, SpO2), Circulation (heart rate, rhythm, blood pressure, peripheral perfusion, temperature), Disability (neurological status: GCS, pupillary response), Exposure (full body assessment for injuries, signs of hypothermia).
Investigations:
Initial investigations include pulse oximetry, arterial blood gases (ABGs) to assess oxygenation, ventilation, and acid-base status
Complete blood count (CBC), electrolytes, glucose, renal and liver function tests
Chest X-ray to assess for aspiration, pulmonary edema, or pneumonia
ECG to detect arrhythmias, especially in hypothermic patients
In suspected hypothermia, core body temperature measurement (rectal, esophageal, or bladder probe) is paramount
Consider cardiac enzymes and coagulation profiles if indicated.
Differential Diagnosis:
Other causes of cardiopulmonary arrest in a water environment should be considered, such as sudden cardiac events, trauma, or severe asthma exacerbations
Differentiating between freshwater and saltwater drowning is less critical for immediate management but can have implications for electrolyte shifts and lung pathology, though this distinction is often overemphasized in current guidelines
Hypothermia itself can mimic other conditions due to reduced metabolic activity and altered mental status.
Management
Initial Management:
Immediate airway management: open airway, remove gross debris, suction
Provide positive pressure ventilation (bag-valve-mask or advanced airway) with supplemental oxygen
Initiate CPR if pulseless
Rapid rewarming in hypothermic patients is critical
Gastric decompression may be necessary if vomiting occurs or gastric distension is significant
Early transport to a facility capable of managing complex pediatric cases.
Medical Management:
Ventilatory support: High-frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation with PEEP to maintain alveolar recruitment and oxygenation
Surfactant administration is experimental but may be considered in severe ARDS
Fluid management: cautious fluid administration to avoid worsening pulmonary edema while maintaining adequate perfusion
Pharmacological support: Inotropes and vasopressors (e.g., dopamine, norepinephrine) for hemodynamic instability
Bronchodilators may be used cautiously if bronchospasm is present
Steroids are generally not recommended for ARDS due to lack of proven benefit and potential harm.
Surgical Management:
Surgical interventions are rarely primary management for drowning itself
However, if concurrent injuries (e.g., trauma) requiring surgical repair are identified during the initial assessment, they should be addressed promptly
Tracheostomy may be considered for prolonged mechanical ventilation, but this is a supportive measure rather than a direct treatment for drowning.
Supportive Care:
Continuous cardiorespiratory monitoring
Strict fluid balance monitoring
Nutritional support: early enteral feeding when hemodynamically stable
Prevention of secondary infections: meticulous hygiene, antibiotic judiciousness
Neurological monitoring: regular GCS assessment, consideration for intracranial pressure monitoring in severe cases
Rewarming protocols for hypothermia are vital: passive rewarming (remove wet clothing, warm blankets) and active rewarming (warm IV fluids, warmed humidified oxygen, warmed humidified air, peritoneal lavage, pleural lavage, gastric lavage, cardiopulmonary bypass for severe cases)
Core rewarming is crucial.
Complications
Early Complications:
ARDS, pulmonary edema, aspiration pneumonia, pneumothorax, cerebral edema, seizures, cardiac arrhythmias, electrolyte disturbances (hyponatremia, hypokalemia), acute kidney injury, disseminated intravascular coagulation (DIC).
Late Complications:
Neurological deficits (cognitive impairment, motor deficits, developmental delay), persistent respiratory issues, psychological sequelae (post-traumatic stress disorder), recurrent pneumonias.
Prevention Strategies:
Primary prevention focuses on water safety: constant supervision of children around water, teaching swimming skills, fencing swimming pools, avoiding alcohol and drugs around water, and using life jackets
Secondary prevention in healthcare settings involves prompt and effective resuscitation, aggressive management of hypothermia and ARDS, and vigilant monitoring for complications.
Prognosis
Factors Affecting Prognosis:
The duration of submersion, water temperature (hypothermia can be neuroprotective), effectiveness of initial resuscitation, neurological status at presentation (GCS score), presence of hypothermia, and development of ARDS are key prognostic factors
Younger age and better pre-drowning health are generally associated with better outcomes.
Outcomes:
Outcomes range from complete recovery to severe neurological impairment or death
Children with shorter submersion times, good neurological status, and no hypothermia generally have better prognoses
Survivors of prolonged submersion or those with severe ARDS have a higher risk of long-term morbidity.
Follow Up:
Survivors require long-term follow-up to monitor neurological development, respiratory function, and psychological well-being
Rehabilitation services may be necessary
Regular pediatric and developmental assessments are crucial
Parents should be educated about potential long-term issues and signs to watch for.
Key Points
Exam Focus:
Prioritize initial ABCs and oxygenation in drowning
Recognize hypothermia as a potential protective factor and its management
Understand ARDS development and ventilatory strategies (PEEP, FiO2)
DNB/NEET SS will test management of refractory hypoxemia and hemodynamic instability
Remember the importance of core rewarming for hypothermia.
Clinical Pearls:
Don't underestimate the neuroprotective potential of hypothermia in cold-water drownings
avoid aggressive rewarming if hemodynamically stable and neurologically impaired
Freshwater vs
saltwater distinction is less important than immediate respiratory support
Always assess for underlying trauma
Early involvement of PICU is essential for severe cases.
Common Mistakes:
Delaying airway management or ventilation
Overly aggressive rewarming in hypothermic patients without considering consequences
Underestimating the severity of ARDS or its management
Neglecting neurological assessment and follow-up
Inadequate fluid management leading to pulmonary edema.