Peds in a Pod: Submersion

Splash!!!

Welcome to the first entry of our monthly pediatric blog. Here we will talk about evidence based medicine and it’s clinical utility in the ER with our younger patients. Enjoy!

Here’s a case to get us started. You’re working in the ER in early June when you get a notification from EMS that they are bringing in a 4 year old girl who was found facedown in her pool. EMS states that she was in the water for no more than five minutes as per her mother. They state that the mother removed the patient from the water and immediately started CPR, they also report that the temperature of the water was fairly cold in the high 60s°F, low 70s°F. EMS placed the patient in C-spine immobilization and continued CPR. The patient arrives in the ED 3 minutes later with CPR in progress. She is cold, pulseless with dilated and fixed pupils. Her core temperature is 88°F. What should you do next? When should you terminate your efforts?

Up here in the Northeast summer is right around the corner and the incidence of drowning increases. As per the 2002 World Congress on Drowning, held inAmsterdam, the consensus definition for drowning is a process resulting in primary respiratory impairment from submersion in a liquid medium. Implicit in this definition is that a liquid-air interface is present at the entrance to the victim’s airway, which prevents the individual from breathing oxygen. The true incidence of drowning is actually unknown because it is not mandatory to report drowning deaths. Estimates range from 150,000 to 500,000 deaths per year worldwide. The total number of drowning accidents is estimated to be 500 to 600 times higher. Drowning is a leading cause of mortality in children between 1 and 14 years of age with a bimodal distribution of children less than 5 and then children 15-25. Death by submersion is the second most common cause of accidental death in children, exceeded only by motor vehicle accidents.

So what happens exactly? Typically after submersion, panic starts and there is some voluntary breath holding (children about 10-20 seconds and adults about 60 seconds). Then the reflexive inspiration occurs causing aspiration and reflex laryngospasm when the water contacts the lower respiratory tract. Water is swallowed and the laryngospasm stops and the victim actively breathes in the liquid medium. Hypoxia and resultant ischemia are typically the cause of morbidity and mortality in drowning. There is increased permeability of the capillary endothelium and surfactant disruption causing ALI/ARDS. Aspiration leads to abnormal surfactant function which causes alveolar collapse, atelectasis, intrapulmonary shunting, and pulmonary injury/hypertension. The resultant hypoxemia then causes neuronal injury and other significant end organ injuries (i.e. fatal cardiac dysrhythmias); it is important to note that electrolyte abnormalities do not usually occur from the drowning itself but may result from the acidosis and hypercarbia that occurs.

Continued aspiration of cold water can produce extremely rapid core cooling as long as circulation remains intact resulting in hypothermia (core temperature below 35°C/95°F). This acute submersion hypothermia may protect the brain temporarily from lethal, especially if it occurs prior to the onset of brain ischemia

PREHOSPITAL CARE– Focus on resuscitationà PALS (push hard, push fast), supplemental O2, C-spine immobilization is ONLY needed if there is a history of diving, significant trauma or if the patient was intoxicated or under the influence of any illicit drugs (younger patients tend to have less incidence of traumatic drowning). In a study conducted by Watson et al. in the journal of trauma a cohort of 2,244, 11 patients (0.5%) had an n incidence of cervical spine injury. These 11 patients had drowned in open bodies of water, had clinical signs of serious injury, and had a history of diving, motorized vehicle crash, or fall from height. No C-spine injuries occurred in 880 low-impact submersions.

The Heimlich maneuver SHOULD NOT be attempted unless there is suspicion for a foreign body as it could increase the risk of aspiration resulting from the abdominal thrusts.

ED CARE– ABCDE!!!! Airway– Supplemental O2 or intubation (remember vent settings for ALI/ARDS!!) if necessary. Use C-spine precautions if warranted. Breathing– There may be bronchospasm which can be treated with beta 2 agonists if the patient can tolerate it. There may also be an increased work of breathing which may require CPAP or some form of PEEP in order to recruit the collapsed alveoli. Several case reports have described the use of surfactant but data is limited , and no large RCTs have been performed to evaluate its use. It’s also expensive and there is limited availability making it not a routine part of care.

Circulation-Volume depletion may occur and IVF is often required. Hypotension may ensue secondary to a cold diuresis because antidiuretic hormone (ADH) release is decreased after vasoconstriction, which causes blood to move to the core causing central volume receptors to sense fluid overload. Disability– Perform a baseline neuro exam as well as document the size and reactivity of the pupils. Exposure– Remove wet clothing, inspect for hypothermia or signs of other injuries.

Managing Hypothermia– Rewarming techniques should be used until the patient is warmed to approximately 32°C to 34°C (90°F-94°F). There are no published RCTs of hypothermia in children after cardiac arrest. Current recommendations are based on extrapolation from existing RCTs in adult and newborn humans. The American Heart Association guidelines in 2006 recommend that hypothermia be considered in children for 12 to 24 hours who remain comatose after resuscitation from cardiac arrest. Further study is also needed to establish therapeutic hypothermia guidelines and recommendations for monitoring/ correcting associated electrolyte abnormalities, cold dieresis, hyperglycemia, and mechanisms to avoid temperature fluctuations in treatment. Temperature fluctuations, especially temperature below the target range of 32°C (90°F) have been associated with increased mortality.

ECMO!!!- The use of extracorporeal membranous oxygenation (ECMO) in pediatric critical care has been well-established, and its use for selective circumstances, such as post cardiac surgery with depressed myocardium, has shown success. An advantage of extracorporeal rewarming in drowning victims is early restoration of normoxic cerebral perfusion regardless of the cardiac rhythm, reduction of the blood viscosity, and controlled restoration of body temperature. Extracorporeal rewarming was used in the longest submerged patient that survived neurologically intact (child’s core temperature was 19°C [66°F], and she was submerged for at least 66 minutes).

NOT RECOMMENDED– Steroids have not been shown to increase survival. Prophylactic antibiotics have not been shown to affect outcomes and are not recommended unless the drowning occurred in contaminated waters (i.e. sewage)

PROGNOSIS– Currently there are some scoring systems that have been mentioned (i.e. Orlowski system, PRISM scores) but they have low specificities and sensitivities and are cumbersome to use in the ER and contain some subjective measurements. Because of this, there are no absolute reliable measures indicators or measurements of survival or death. However based on cases in the past, the following have been mentioned as favorable factors: a) Witnessed arrest b) Intact pulses upon arrival to emergency department c) Bradycardic rhythm (as opposed to asystole) d) Submersion time < 5 mins e) Alert upon arrival to emergency department f) Reactive pupils g) Bystander CPR or prompt initiation of resuscitation h) Hypothermiaà Hypothermic protection is dependent on slowing cerebral metabolism before irreversible hypoxic-ischemic injury has occurred and only occurs in the most frigid water. The speed of cooling may be more important than the actual temperature. If the body is quickly cooled before ischemia has occurred, this appears to be protective. If a child is immersed in icy water, he is cooled quickly and his brain may cool to protective levels prior to ischemic effects.

DISPOSITION– Any child that arrives in a serious state, such as cardiopulmonary arrest, and survives deserves special attention. In these children, we must resuscitate enough, yet not too much. It has been shown that aggressive and prolonged resuscitation simply increases the number of survivors with poor neurological outcome. A quick bedside echo is helpful in a resuscitation to evaluate the presence of cardiac motion. In addition, it is also reasonable to resuscitate a child until mild hypothermia (32°C-34°C [90°F-93°F) is reached; remember someone is not dead until they are warm and dead.

Patients that initially require oxygen or improve after a trial of bronchodilators also deserve diligent monitoring. Ultimately, the decision is based on the history, physical, ED course, the appearance of the child, reliability/comfort of the parents and accessibility to return to the hospital. Basically this all means that if a child looks great and does not have any respiratory difficulty, discharging them home after 4 hours in the ED is recommended. It is generally recommended that symptomatic patients should be admitted until symptoms resolve.

PREVENTION– Promote appropriate barriers and improve family education that all children can be at risk, even strong swimmers. Actions as simple as placing a fence (greater than 4 feet tall) to separate the pool from the house can prevent over 50% of drowning accidents. Put toys away in a safe place as they tend to lure children towards the pool and may cause accidental falls. And above all, appropriate supervision-àSpecific recommendations regarding adult supervision from the Centers for Disease Control include no alcohol use, no phone use, and no performing other tasks while supervising children around water. Families must be aware that epilepsy is a risk factor for submersion injury, including drowning in tub. Buckets of water may also cause another form of drowning as well as unattended infant bath seats.

References:

Watson R, Cummings P, Quan L, et al. Cervical spine injuries among submersion victims J Trauma. 2001;51:658-662.

Staudinger T, Bankier A, Strohmaier W, et al. Exogenous surfactant therapy in a patient with adult respiratory distress syndrome after near drowning. Resuscitation. 1997;35:179- 182.

Cubattoli L, Franchi F, Coratti G. Surfactant therapy for acute respiratory failure after drowning: Two children victim of cardiac arrest. Resuscitation. 2009;80:1088-1089.

EBMedicine.net: EM Practice- Pediatric Submersion Injuries June 2011

Adult respiratory distress syndrome and artificial surfactant replacement in the pediatric patient. Perez-Benavides F, et al. Texas Tech Health Sciences Center School of Medicine.

Bolte RG, Bowers RS, Thorne JK, et al. The use of extracorporeal rewarming in a child submerged for 66 minutes. JAMA. 1988;260(3):377-379.

Fink EL, Clark RS, Kochanek P, et al. A tertiary care center’s experience with therapeutic hypothermia after pediatric cardiac arrest. Pediatric Crit Care Med. 2010;11(1):66-74.

Brenner R. Prevention of drowning in infants, children, and adolescents. Pediatrics. 2003;112:440.

Causey A, Tilelli J, Swanson M. Predicting discharge in uncomplicated near-drowning. American Journal of Emergency Medicine. 2000;18(1):obtained from MDConsult.com.

Blaivas M, Fox JC. Outcome in cardiac arrest patients found to have cardiac standstill on the bedside emergency department echocardiogram. Acad Emerg Med. 2001;8(6):616-621.