It’s summer. Drowning is a tragedy that kills about half-million people each year worldwide, and is the second leading cause of traumatic death among children age 1 to 4 in the United States. Death from drowning (i.e. respiratory failure secondary to submersion/immersion in a liquid) occurs acutely secondary to hypoxia, laryngospasm, and aspiration. If surviving the initial event, complications such as ARDS and cerebral ischemia are usually the common final pathways (though they are susceptible, as you may imagine, to any of the complications facing critically ill, ventilated patients in the ICU).
Despite myths to the contrary, there is little actual difference in the pathophysiology between fresh- and saltwater drowning; moreover, your treatment varies not at all. One figure from an NEJM article summarizes the mortality of the patient based on their initial presentation to the ED (and rescuers). While the airway may be complicated by fluids, vomiting (aspiration of stomach contents is common), and edema, management of the patient in cardiac arrest secondary to respiratory arrest is no different: secure the airway, provide oxygenation (their shunt/ARDS may be difficult to overcome, acutely and in the coming days if they survive–and may be great candidates for ECMO in the right circumstances).
Poor survival is associated with prolonged submersion time (>10 minutes), prolonged immersion time (>5 minutes), warm water drowning, and delays in CPR (>10 minutes)–none of which should be surprising. Neurologic prognostic factors such as fixed pupils, poor GCS, diffuse edema on CT scan, and profound acidosis all hold true here.
Interestingly, cervical spine injury is actually pretty rare (though should be considered), any only makes up about 0.5% of drowning cases. Antibiotics are only expressly indicated in the case of drowning secondary to dirty liquid (think: sewer water), but I don’t think anyone would fault you for considering them otherwise.
Most of the statistics quoted here are from the Szpilman 2012 NEJM summary article. For other good sources, try these articles from Deranged Physiology, Life in the Fast Lane, or emDOCs.