Drowning Three Peaks • Toddlers • Adolescents • Elderly In drowning... air hunger and usually panic Reflex inspiratory efforts lead to aspiration of water and laryngospasm asphyxia and hypoxaemia / acidosis Hypoxemia Occlusion of airways with water & particulate debris Changes in surfactant activity Bronchospasm Right-to-left shunting increased Physiologic dead space increased Asphyxia Laryngospasm maintained Relaxation of the airway Respiratory arrest Water enters lungs Cardiac arrest Surfactant washout V / Q mismatch* “Dry drowning” “Wet drowning” *mechanism in fresh and salt water slightly different Near Drowning Pulmonary Injury • Aspiration as little as 1-3 cc/kg can cause significant effect on gas exchange – Increased permeability – Exudation of proteinaceous material in alveoli – Pulmonary edema – decreased compliance Anoxic-ischemic injury • All organs may injured from hypoxia and ischemia . • CNS injury (ICP ,cerebral edema) The most frequent cause of mortality and long- term morbidity Pathophysiologic Changes Neurologic Effects • Cerebral edema 24 - 72 hours following injury • Loss of autoregulation of blood flow • Reperfusion injury Anoxic-ischemic injury • Pulmonary: wash out surfactant Pulmonary edema, ARDS • Cardiovascular: Arrhythmia( hypothermia ,hypoxemia) • Acid-base • Electrolytes Anoxic-ischemic injury • Renal ATN (hypoxemia,shock, hemoglobinuria) • Gasterointestinal hepatic trasaminases and serum pancratic enzymes are often acutely elevated Hypothermia • Mild hypothermia:T(34-36) • Moderate hypothermia T(30-34) increase oxygen consumption. • Below T 30: (sever hypothermia) shivering ceases and cellular metabolic rate decreases On moderate to sever hypothermia we have progressive bardycardia and hypotention hypoventilation • Deep coma with fixed and dilated pupils and absent reflexes at T (25-29) may give the false appearance of death Initial Assessment and Resuscitation Restating the obvious Initial Assessment and Resuscitation • Specialized issues – Abdominal thrust should not be used: thought to clear airways of liquid obstruction • Amount of fluid is usually small and non- obstructive • May increase risk of aspiration of gastric contents • Do not waste time, correcting hypoxia is paramount Immediate hospital management • Assess and manage ABC • 100% oxygen • Pulse oximetry (watch for false readings caused by peripheral shutdown and acidosis) • ABGs, FBC, U&E • CXR • Observation • Management of associated hypothermia Initial Assessment and Resuscitation • IV fluids N/S 10-20CC/kg or ringer lactate • Don’t use hypotonic serum or glucose • Marked vasoconstriction:epinephrine Hospital-based evaluation • Observed least 6-8 hr if they are asymptomatic on presentation to the ED serial monitoring of vital sign and pulmonary and neurologic assesment • 50% asypmtomatic child experience some level of respiratory distress • Pulmonary edema during the 1st 4-8 hr after submersion Laboratory • Arterial blood gases • Electrolytes • BUN/ Creatinine • Platelets/ PT & PTT/ CBC • Serum & Urine Hemoglobin Labs & tests • Very mild electrolyte changes • EKG – Sinus tachycardia & nonspecific • Moderate leukocytosis ST-segment and T-wave • Hct and Hgb usually normal changes initally – Reverts to normal within hours – Fresh water aspiration, the Hct – Ominous - ventricular arrhythmias, complete heart may fall slightly in the first 24 hrs block due to hemolysis • CXR – Increase in free Hgb without a change in Hct is common – May be normal initially despite severe respiratory disturbances • DIC occasionally – Patchy infiltrates • ABG – metabolic acidosis & – Pulmonary edema hypoxemia Imaging • Head CT scan is not helpful unless : 1. Suspicion of associated trauma injury 2. to rule out other possible causes of coma • MRI may detect change associated with hypoxic- ischemic injuries Therapy for the lungs • CPAP or PEEP • Aerosolized β-agonists for bronchospasm • Bronchoscopy • Prophylactic antibiotics have not been shown to be beneficial • Steroids: – No controlled human studies to support use – Animal models and retrospective studies in humans have failed to demonstrate benefit Brain therapy • ICP monitoring - not indicated, typically irreversible hypoxic cellular injury • Brain CT – not indicated, • Mild hyperventilation-Osmotherapy – diuretic-barbiturates not indicated • Corticosteroids (dexamethasone) - no proven benefit • Seizures - treat aggressively with fosphenytoin or phenytoin • Shivering or random, purposeless movements can increase ICP • Hypothermia and barbiturate coma - highly controversial & unlikely to benefit the patient Bad prognostic indicators • Submerged >10 min • Age <3 years • Time till BLS >10 min • Initial ABG pH <7.1 • CPR >25 min • Initial core temp <33o • Initial GCS <5 deep • hyperglycemia coma • apnea Good Prognostic Factors • Older child or young adult • Cold water • Adequate CPR/on scene ACLS/BLS • Conscious • Short submersion • Healthy Outcomes Long Term Prognosis • Overall, >15% survivors with significant neurologic deficits • Children with spontaneous, purposeful movements and had a normal brainstem examination at 24 hours progressed to full recovery • Those without these findings by 24 hours suffered severe neurologic deficits or death Recommendations • Pre-hospital resuscitation, including early intubation, ventilation, vascular access, and administration of advanced life support medications • Continued resuscitation and stabilization in the ED • Full supportive care in the ICU for a minimum of 48 hrs.