DROWNING

INTRODUCTION Primary respiratory impairment due to submersion in liquid medium Outcome may be immediate death, delayed death or morbidity or life without morbidity

DEFINITIONS Drowning : Death by suffocation in a liquid medium. Near drowning: Immersion seeking medical attention in which the patient survives for atleast 24 hours. Wet drowning: Water in the lung due to aspiration Dry drowning: Dry lungs due to laryngospasm

PATHOPHYSIOLOGY Laryngospasm Increased Left ventricular afterload Systemic hypoxemia & acidosis Cardiac depression Apnoea Alveolar hypoxia and hypercapnia Laryngospasm Increased Left ventricular afterload Aspiration of water ARDS & altered surfactant Pulmonary edema

ASPIRATION Aspiration of 1-3ml/kg liquid causes deleterious effects Fresh water enters microcirculation and destroys surfactant. Atelectasis, decreased compliance and V/Q mismatching Salt water causes exudation of protein rich fluid in the alveoli, alveolocapillary memb. damage and shunting Aspirated fluid can cause pulmonary vasoconstriction and hypertension.

MULTI ORGAN FAILURE Hypoxemia and acidosis will depress the myocardium VF can occur in near drowning in very cold water. Hepatic and renal failure can occur. DIC also can develop.

OTHER SEQUELAE Direct injury to the head and neck can also cause brain damage. Sometimes, aspiration of sand, silt, vomitus can obstruct bronchi causing bronchospasm, pneumonia and abscess Rhabdomyolysis and acute tubular necrosis

COMORBID CONDITIONS Seizures Myocardial infarction Diabetes Hypoglycemia Suicidal tendencies Neurological illness

INVESTIGATIONS CBC, RFT, ABG, pulse oximetry ECG X ray chest, CT brain, X ray or CT cervical spine Blood alcohol Urine toxicology screen for the drugs

PREHOSPITAL CARE Remove the victim from the water in prone position after ruling out the neck injury No need to give compressions for the removal of water, as they are not proven to remove the fluid and delay the CPR. Start CPR, if needed. Begin rewarming. Remove the cloth immediately. Shift the patient to the hospital as early as possible Give adequate support to the neck

IN HOSPITAL CARE Put NG tube to aspirate the gastric contents before intubation. Endotracheal intubation. Rewarming Correction of acid base disturbances and electrolytes Treating the underlying medical illness.

ENDOTRACHEAL INTUBATION Intubation and mechanical ventilatory support : Failure of trial with non invasive ventilation with Bilevel positive airway pressure ventilation in conscious victims A-a gradient of > 60-80mmHg PaCo2 > 45mmHg Altered level of consciousness and not able to maintain the airway High PEEP will help to remove the water from the lungs ( 4 cmH2O to 14 cmH2O)

REWARMING Wrap the patient with warm blankets. Give warm fluids through nasogastric tube. We can give warm(40 C) fluids through IV and bladder lavage to increase the core temperature. Other measures like extracorporeal blood warming and open heart massage also have been tried.

OTHER MEASURES Treat the underlying medical illness Treat other conditions like pneumonia and multiorgan dysfunction Do not abandon the resuscitation until the body temperature reaches 30C Attempt central venous access cautiously as it may stimulate the hypothermic atrium causing dysrhythmias.