Overview Definition Epidemiology Accidental vs. Non-accidental drowning Pathophysiology Management Prevention
Definition2002 World congress on drowning defined drowning as “a process resulting in primary respiratory impairment from submersion in a liquid medium”Near drowning refers to survival (even if temporary) beyond 24 hours after a submersion episode.Shepard, Suzanne et al. Drowning. Emedicine.medscape.com/article/772753-overview. Updated 6/9/2009 .
Fatal Drowning Statistics In 2005, 3,582 fatal unintentional drownings in U.S. 1 in 4 drownings were children < 14 years old Drowning is the second-leading cause of unintentional injury-related death for children ages 1 to 14 years India has a drowning mortality rate of 8.5/100000 population.Water Injuries-Fact Sheet. www .cdc.gov/HomeandRecreationalSafety/Water-Safety/waterinjuries-factsheet Accessed25 Sept 2009.
Location of DrowningBrenner et al. looked at death certificates from victims of unintentional drownings in 1995Infant drownings: 55% in bathtubsAge 1-4 years, 56% in artificial pools and 26% in other bodies of freshwaterChildren 63% of drownings were in natural bodies of freshwater Brenner RA, Trumble AC, Smith GS, Kessler EP, Overpeck MD. Where children drown, United States, 1995. Pediatrics 2001;108(1):85 ﾐ
Features which differentiate between accidental, non-accidental, and homicidal submersion injuries to children Accidental submersion: Typically a baby momentarily left alone or with a sibling in the bath Majority of children 8-15 months of age Child the youngest in the family No features suggesting child abuse Epilepsy related: Child with history of epilepsy Bathing alone A child older than 24 months Non-accidental submersion: Atypical submersion description, with inconsistent details Late referral to hospital Associated history of child abuse Child outside 8-24 month age span Child left with unsuitable carer Homicidal drowning: Maternal history of mental illness Child outside the 8-24 month age range Previous history of child abuse Kemp, Alison et al. Accidents and child abuse in bathtub submersions. Archives of Disease in Childhood 1994; 70: 435-438.
Signs & symptoms75% of kids who develop sxs do so within 7 hours of eventComa to agitated alertnessCyanosis, coughing, and the production of frothy pink sputumTachypnea, tachycardiaLow-grade feverRales, rhonchi & less often wheezesSigns of associated trauma to the head and neck should be sought
“Hypoxic March of Drowning”A pathophysiology summary 1. Involuntary submersion Voluntary apnea, tachycardia, hypoxia, hypercarbia 1. Involuntary inspiration Triggered by hypercarbia and hypoxia arterial hypoxemia, tissue hypoxia, tissue acidosis, and tachycardia 1. Water enters lungs Increased peripheral airway resistance, pulmonary vessel vasoconstriction/hypertension with shunting of blood, decreased lung compliance, decreased surfactantPearn, John. The management of near drowning. BMJ 1995. (291) 1447-1452
“Hypoxic March of Drowning”continued4. Decompensation -gasping with further inhalation -swallowing with emesis -loss of consciousness4. Neuronal dysfunction -blood brain barrier breaks down4. Cardiac dysfunction -bradycardia, arrhythmias, asystole7. Brain Death8. Somatic Death
Diving ReflexInfants and young childrenSudden contact with water less than 20 degrees CelsiusCauses: Bradycardia vasoconstriction of nonessential vascular beds shunting of blood to the coronary and cerebral circulation Shepard, Suzanne et al. Drowning. Emedicine.medscape.com/article/772753-overview. Updated 6/9/2009 .
Dry Drowning10-20% of patients experience a laryngospasm that prevents aspiration of fluid into the lungsTight spasm often persists until cardiac arrestLungs remain dryLarge volumes of fluid ingested into stomachMajor cause for electrolyte abnormalities in children (hyponatremia from fresh water, hypernatremia from salt water)
Wet Drowning1-3 mL/kg water aspirated hinders gas exchangeWhen fluid is in the lungs, vagus nerve stimulates vasoconstriction pulmonary vessels and pulmonary hypertensionFreshwater diffuses rapidly across alveolar- capillary membrane and saltwater damages the membraneSurfactant is denatured by freshwater and washed away by salt waterIn both salt water and freshwater aspiration, compliance is decreased
Hypoxic-Ischemic EncephalopathyInitial phase Energy failure from hypoxia/ischemiaReperfusion Injury 6-24 hours later Cerebral edema, apoptosis
Mechanism of Hypoxic-Ischemic EncephalopathyExcitatory amino acids, glutamate and aspartate, are released in response to hypoxia/ischemiaActivation receptors, NMDA, AMPA, Kainate Ion channels open Influx of calcium into cells Cell deathLipid peroxidation of cell membranes Destruction of Na+/K+ ATPase Cerebral edema, neuron deathIncreased rate of apoptosis Related to influx of calcium into cell and nucleus
Complications of hypoxic-IschemicEncephalopathyAutonomic instability Hypertension Tachycardia Diaphoresis Agitation Muscle rigidity
AspirationChemical Pneumonia pH less than 2.5 Volume greater than 0.3mL/Kg Inflammatory reaction by cytokines TNF-alpha, IL-8Bacterial Pneumonia Anaerobic organisms
Other organ involvementOccur 24-72 hours after initial insultHeart: decreased contractility, dilation, tricuspid regurgitation, stress induced cardiomyopathyRenal: acute tubular necrosis, oliguria, anuriaHepatic: increased LFT’s, hypoalbuminemia, coagulopathy, hyperbilirubinemiaRhabdomyolysis
DifferentialsChild Abuse & Neglect: Physical AbuseChild Abuse & Neglect: Sexual AbuseMunchausen Syndrome by Proxy
WORKUP-Laboratory Studies The following studies are indicated in near drowning: Blood gas analysis with co-oximetry to detect methemoglobinemia and carboxyhemoglobinemia CBC count, prothrombin time with international normalized ratio (INR), partial thromboplastin time, fibrinogen, D-dimer, fibrin split products
Serum electrolytes (with glucose)Liver enzymes, especially aspartate aminotransferase and alanine aminotransferaseRenal function tests (BUN, creatinine)
Drug screen and ethanol level (consider)Continuous pulse oximetry and cardiorespiratory monitoring (may be needed)Cardiac troponin I testing (may be useful as a marker to predict children who have an elevated risk of not surviving to hospital discharge)
Imaging StudiesChest radiographyHead CT and cervical spine imaging if trauma suspectedExtremity, abdominal, pelvic imaging if clinically indicatedEchocardiography if myocardial dysfunction present
Other TestsConsider electrocardiography if the patient has arrhythmias. Monitor the patient if rewarming is necessary, because dysrhythmias are common when rewarming patients who suffer cold-water immersion injuries.
Swan-Ganz catheter for monitoring cardiac output and related hemodynamic parameters may be useful in patients with unstable cardiovascular status or in those who require multiple inotropic and vasoactive medication requirements.
Labs & testschangesVery mild electrolyteModerate leukocytosisHct and Hgb usually normal initallyFresh water aspiration, the Hct may fall slightly in the first 24 hrs due to hemolysisIncrease in free Hgb without a change in Hct is commonDIC occasionallyABG – metabolic acidosis & hypoxemia
EKG-Sinus tachycardia & nonspecific ST-segment and T-wave changesReverts to normal within hoursOminous - ventricular arrhythmias, complete heart blockCXR-May be normal initially despite severe respiratory disturbancesPatchy infiltratesPulmonary edema
Management: necessary Bystander resuscitation CPR 30% pediatric cardiac arrest patients receive bystander CPR PUSH HARD, PUSH FAST Minimize interruptions Some bystander CPR, better than none Heimlich maneuver contraindicated because it can cause emesis, aspiration Rescue breaths at rates > 20 breaths/min contraindicated because venous return can be obstructed
Arrival to the hospital• General Assessment: • Appearance • Work of Breathing • Circulation• Primary Assessment: • Airway • Breathing • Circulation • Disability • Exposure Pediatric Advanced Life Support Provider Manual
Management ET intubation: Cannot maintain PaO2 > 80 mm Hg on 100% O2 by face mask Inability to protect airway or handle secretions Respiratory failure - PaCO2 >45 mm Hg Worsening ABG results Peep: shifts interstitial pulmonary water into the capillaries increases lung volume by preventing of alveolar collapse provides better alveolar ventilation and decreases capillary blood flow
Management ECMO If despite intubation, cannot oxygenateBroncoscopy Removal of vomit, debris in lungsAlbuterol For bronchospasmAspiration Pneumonia Clindamycin for bacterial pneumonia is drug of choiceManage electrolyte abnormalities hypoglycemia
Management of HypothermiaTwo types: 1. Rapid immersion in cold water, rapid onset of hypothermia, core temperature < 86 degrees F Neuroprotective, preferential shunting of blood to heart, brain 2. Gradual onset of hypothermiaRapidly re-warm patients with gradual onset of hypothermia patients at risk for ventricular fibrillation and neuronal injury
Guidelines for treating cold-waterdrowningPatients with severe hypothermia may appear dead because of profound bradycardia and vasoconstriction.Resuscitation should continue while aggressive attempts are made to restore normal body temperature.
ManagementDo not stop resuscitation of a patient until their core temperature is at least 30 degrees Celsius!
Guidelines for treating warm-water drowning:Patients arriving at the emergency department in cardiopulmonary arrest after a warm-water submersion have a dismal prognosis. The benefits of resuscitative efforts should be continuously reassessed in such situations
Connpatients, the Conn classification system may beFor other classification system: used as a guideline to quantify the extent of cerebral hypoxia.Category A – AlertCategory B - Blunted consciousness; admit and observe for pulmonary compromise, which may result in hypoxemia and worsen CNS injuryCategory C - Comatose (C1 - decorticate, C2 - decerebrate, and C3 - flaccid [worse prognosis than C1])
PrognosisRelated to duration of submersion Time greater than 25 min, prognosis is poorIndicators of poor outcome: Fixed, dilated pupils Low GCS comaSurvivors of resuscitation have good neurological outcomes if they show purposeful movement within 24 hours
Prevention Designate a responsible adult to supervise water related activities Adults should not be doing other tasks at the same time as supervision, no alcohol while supervising Swim with a buddy No alcohol before, during swimming Learn to swim AAP does not recommend swimming lessons as a primary prevention method for children under 4 years old Learn CPRWater Injuries-Fact Sheet. www .cdc.gov/HomeandRecreationalSafety/Water-Safety/waterinjuries-factsheet Accessed 25Sept 2009
PreventionFence swimming pools on 4 sides, at least 4 feet tallDo not use air or foam filled water toys in place of life-jackets