Wk 12 PPT Near Drowning (2)
NEAR DROWNING
Focus on Chapter 42 of Des Jardins and Chapter 30 of Egan.
TERMINOLOGY (1 OF 2)
Drowning:
Definition: Respiratory impairment due to submersion or immersion in liquid, leading to suffocation and potential death.
Outcome: If the individual does not survive, it is termed fatal drowning.
Near Drowning:
Definition: Incidents with respiratory impairment from submersion but survival with medical intervention.
Outcome: Survivors may experience respiratory distress, hypoxia, or other complications.
TERMINOLOGY (2 OF 2)
Immersion:
Definition: Being partially or completely submerged in a liquid; does not necessarily lead to drowning.
Outcome: Can be accidental without breathing impairment.
Submersion:
Definition: Body is partially or completely under water, often leading to breathing difficulty.
Outcome: Can lead to drowning or near drowning.
STATISTICS AND EPIDEMIOLOGY
CDC reports over 4,500 drowning deaths annually from 2020 to 2022.
Children (1-4 years): Leading cause of death in this group due to drowning.
Black Individuals: 28% increase in drowning rates from 2019 to 2021; second-highest death rate in the U.S.
American Indian/Alaska Native Communities: Highest drowning rates, stable over time.
Approximately 40 million adults in the U.S. (15.4%) cannot swim; 54.7% have never taken swimming lessons.
EPIDEMIOLOGY
Age Distribution of Drowning Deaths:
First Peak: Children under 5; risk factors include lack of supervision and limited swimming skills.
Second Peak: Young adults aged 15-24; associated with water-related accidents, alcohol use, and risky behaviors.
THE DROWNING SEQUENCE
Steps: Initial immersion → Laryngospasm → Gasping/Respiratory struggle → Water inhalation → Loss of consciousness → Cardiac arrest and death.
TWO PATHOLOGICAL REFLEXES
1. Reflex Laryngospasm:
Definition: Protective response where vocal cords close, blocking the airway upon water aspiration.
Consequences: Can cause respiratory distress, hypoxia, and airway obstruction if prolonged.
2. Diver's Reflex:
Definition: Physiological response in mammals submerged in cold water, characterized by three responses:
Bradycardia: Reduced heart rate to conserve oxygen.
Peripheral Vasoconstriction: Blood flow directed to vital organs.
Blood Shift: Shunts blood to central body to maintain blood volume.
Protective Function: Helps conserve oxygen during submersion.
DRY DROWNING
Definition: Larynx closes off, preventing water from entering lungs; leads to suffocation due to airway obstruction.
Time Frame: Can occur shortly after event (minutes to hours).
Symptoms: Respiratory distress, coughing, chest tightness after the event.
WET DROWNING
Definition: Larynx relaxes, allowing water into lungs, leading to respiratory failure.
Symptoms: Difficulty breathing, foamy sputum, worsening respiratory distress.
KEY PATHOLOGIC PULMONARY CHANGES
Laryngospasm: Limits water entry initially but may allow damage if failure occurs.
Pulmonary Edema: Fluid accumulation in alveoli; varies with saltwater vs. freshwater drowning.
Surfactant Dysfunction: Caused by damage or washout leading to atelectasis.
Inflammatory Response: Increases fluid leakage, worsening gas exchange.
Hypoxia, Hypercapnia, and Acid-Base Imbalances: Complicate clinical picture; untreated can lead to respiratory failure.
PULMONARY CONCERNS
Alveolar flooding.
Surfactant washout leading to pulmonary edema.
Decreased lung compliance.
V/Q mismatch and intrapulmonary shunt.
Refractory hypoxemia and ARDS.
SALTWATER DROWNING
Osmotic Pressure: Saltwater higher in salinity than blood; causes water to be drawn into alveoli.
Pulmonary Edema: Fluid impairs oxygenation.
Electrolyte Imbalance: High salt content causes serious complications like arrhythmias.
FRESHWATER DROWNING
Osmotic Pressure: Freshwater lower in salinity; causes water influx into bloodstream.
Pulmonary Edema: Rapid dilution of blood leads to significant leakage and impaired oxygen transfer.
Hemodilution: Lowers blood's oxygen-carrying capacity, leading to potential hypovolemic complications.
PULMONARY EDEMA
Associated with pink, frothy sputum.
RECALL QUESTIONS
Reflex Laryngospasm affects airway: B) Involuntary closure of the vocal cords.
Diver's Reflex NOT associated: C) Increased blood flow to extremities.
PRE-HOSPITAL MANAGEMENT
Assessment and Immediate Actions:
Ensure scene safety, check responsiveness and breathing.
Airway Management:
Rescue breathing, CPR for cardiac arrest, intubation if no spontaneous ventilations. Monitor oxygen levels, provide supplemental oxygen.
Control Hypothermia: Remove wet clothing, cover with blankets, and ensure rapid transport.
HOSPITAL MANAGEMENT
Extension of rescue efforts; monitor for hypoxemia, hypercapnia, acidosis.
Administer Narcan if appropriate; use warming techniques (IV solutions, heated lavage).
RULE OF THUMB
Intubation: Consider if ALOC, apnea, or severe hypoxemia present.
CPR: Continue until core body temperature > 35°C. Metabolic processes depend on normal body temperature. Hypothermia complicates heart activity.
OTHER HOSPITAL MANAGEMENT CONSIDERATIONS
Conduct airway clearance and consider bronchoscopy; prone positioning assists in fluid clearance.
Use antibiotics for pneumonia prevention; may require diuretics, inotropic agents, and mechanical ventilation for ARDS.
PULMONARY EDEMA/ARDS
Drowning is a common cause of ARDS, involving pulmonary edema and poor compliance; employ protective lung strategies.
NEUROLOGIC INJURIES
Management aims to prevent ischemia, cerebral edema, and complications; monitor ICP and control seizures aggressively.
GLASGOW COMA SCALE
Eyes Open: 4-1 points, Verbal Response: 5-1 points, Motor Response: 6-1 points. Injury scoring: Minor (13-15), Moderate (9-12), Severe (3-8).
GENERAL PROGNOSIS - POOR OUTCOMES
Key factors for prognosis: Submersion time, water temperature, and initial cardiac rhythm play crucial roles in outcomes.
Higher GCS scores (above 5) are linked to better prognos.
FAVORABLE PROGNOSTIC FACTORS IN COLD-WATER NEAR DROWNING
Younger age, shorter submersion time, colder water temperature, cleaner water quality, minimal struggle, and good CPR technique improve survival chances.
SELF ASSESSMENT QUESTIONS
Continuous CPR until core temperature reaches 35°C serves to revive circulation and organ function.
Clinical manifestations in near-drowning victims: frothy, pink secretions, crackles, indicating severe pulmonary issues.