Drowning: a cry for help.

IN this issue of ANESTHESIOLOGY, Layon and Modell review current evidenced-based management of drowning victims who reach medical care. Modern resuscitation research of the drowning victim now spans decades. This review article expertly and comprehensively evaluates information resulting from that investigation; perhaps as important as that which is said, is that which is not said. Throughout the 1960s and 1970s, Dr. Model and his colleagues provided groundbreaking research describing principally pulmonary and blood electrolyte responses to drowning and the effects of the liquid medium on these responses (e.g., fresh water vs. salt water). That era can now be considered as the golden age of drowning research. Preclinical models were developed and exploited. Clinical case series and experimental interventions were reported that harnessed simultaneous advances in critical care. However, the work did not progress to the level of randomized intervention trials, and the science did not keep pace with that of brain resuscitation research. This is particularly crucial because asphyxial brain injury is often the terminal event or persistent debilitating factor in those resuscitated from cardiac arrest caused by drowning. A review of the PubMed database reveals negligible current effort to better define drowning pathophysiology or clinical management of its victims. Indeed, the majority of papers cited by Layon and Modell were published before 1990. Is this subject of concern to anesthesiologists? Drowning victims are typically treated first at the site of rescue, later in the emergency department, and unless death or hospital discharge ensues, are transferred to medical intensive care units. Although trauma may accompany drowning, this infrequently results in a call for perioperative management. Yet, anesthesiologists pride themselves on their expertise in resuscitation medicine and this offers great opportunity to participate in revitalization of the endeavor to improve management of drowning victims. Drowning is a major public health problem. In the United States, it is a leading cause of accidental death through the first 5 decades of life, with peak incidences occurring during early childhood and adolescence.# Estimates vary but suggest that at least 150,000 to 800,000 people die worldwide from accidental drowning each year, with untold numbers sustaining permanent neurocognitive deficits. Despite the prevalence of this disorder, novel information applicable to medical management has been scant over the past 2 decades. This is held in contrast to major advances in both cardiopulmonary and cerebral resuscitation. Most notably, it has been proved that induced mild/moderate hypothermia initiated after restoration of spontaneous circulation for out-of-hospital ventricular fibrillation cardiac arrest reduces both mortality and neurologic morbidity. This success was predicated on extensive preclinical research. Preclinical models of ischemic and anoxic cerebral injury have dramatically improved, particularly those that allow analysis of long-term outcome. Understanding the immediate and delayed cellular responses to ischemia has radically altered how we think about the response of brain to energy deprivation and reperfusion injury. Knowledge of ischemia and reperfusion injury is highly relevant to drowning and can allow a platform for rational investigation of novel intervention. Yet, little research is performed, and modern, validated, and clinically relevant preclinical models are not available to examine these complex pathologic conditions in the specific context of drowning. It cannot be assumed that simple major cerebral vessel occlusion in laboratory animals will mimic interactions among tissue energy deprivation, temperature shifts, electrolyte abnormalities, and pulmonary injury often associated with immersion in various fluids. Similarly, there is need for clinical research. The earlier the intervention takes place, the larger the effect on a positive outcome. What interventions, achievable in the field, can be implemented to improve functional outcome? Is hyperoxia adverse? Should efforts be made to sustain hypothermia? At either preclinical or clinical levels, both are known to substantively alter outcome from cardiac arrest, but no work has focused on drowning. Within the hospital, little data define the role of intracranial pressure management or electrophysiologic monitoring, cerebral microdialysis, neurochemical markers, tissue oxygen management, pharmacologic intervention, glucose control, rewarming strategies (cold drowning), temperature management, or influence of respiratory care on brain outcome specific to drowning This Editorial View accompanies the following article: Layon AJ, Modell JH. Drowning: Update 2009. ANESTHESIOLOGY 2009;110:1390–401