Abstract
Background
Young patients may survive accidental deep hypothermia with prolonged asystolic circulatory arrest because of protective effects of cold.
Case Summary
An 8-year-old boy fell through pond ice and was submerged for ≥147 minutes. Nadir peripheral body temperature was 7 °C (45 °F). After rewarming with extracorporeal membrane oxygenation, prolonged hospitalization, and neurorehabilitation, the child recovered.
Discussion
This is the longest submersion time and nadir body temperature survived in medical literature. Findings inform and extend time and temperature limits from which human life may be rescued from asystolic hypothermia. This case raises clinical, scientific, and ethical considerations for drowning rescue, organ preservation, and neurologic recovery after prolonged total body ischemia.
Take-Home Messages
Resuscitation and extracorporeal rewarming to save a child may be considered for upward of 2.5 hours of asystolic hypothermia with temperature as low as 7 °C (45 °F). If neurologic recovery is not observed, end-organ preservation on extracorporeal membrane oxygenation may bridge to pediatric organ donation.
Visual Summary An 8-Year-Old Boy Fell Through Pond Ice in Central Pennsylvania
After prolonged submersion, cardiopulmonary resuscitation (CPR) and extracorporeal membrane oxygenation (ECMO) core rewarming in the operating room (OR) were performed. The patient was managed in the pediatric intensive care unit (PICU). The reconstructed timeline is shown. EMS = emergency medical services.
History of Presentation
An 8-year-old boy (26 kg) wearing boots and a snow jacket went outside to play in −3 °C (27 °F) in December in Pennsylvania. Parents discovered sled tracks from home onto broken pond ice through which he fell. A review of parental history, prehospital responder, and emergency medical services documentation revealed underwater submersion time between 147 and 177 minutes. Maximum submersion time was time from leaving home to time pulled from water (177 minutes). Minimum submersion time was time from boy missing to time pulled from water (147 minutes). Submersion time included ground search and ice water grid search by rescue divers (Figure 1).
Figure 1 Rescue Divers Conduct a Grid Search for the Boy in an Ice-Covered Pond After Dark
Ducks are noted in the background, near the pond center. It is believed that the child abandoned his sled in the foreground, walked onto the pond, and fell through ice as he approached the ducks.
Take-Home Messages
•
Resuscitation and extracorporeal rewarming to save a child may be considered for upward of 2.5 hours of asystolic hypothermia with temperature as low as 7 °C (45 °F).
•
If meaningful neurologic function is not observed, end-organ preservation on extracorporeal membrane oxygenation may be a bridge to pediatric organ donation.
The boy was pulled from the frozen pond. Cardiopulmonary resuscitation (CPR) was initiated on firm land. Oral endotracheal intubation and positive pressure manual ventilation were performed. The end-tidal partial pressure of carbon dioxide (PCO2) was 30 mm Hg. No-touch infrared temperature measurement from the upper thigh was twice confirmed to be 7 °C (45 °F). The transport team was instructed not to initiate rewarming. CPR continued for 69 minutes during transport directly to a cardiac surgery operating room at Geisinger Medical Center in Danville, PA.
Past Medical History
The patient has no past medical history.
Differential Diagnosis
The differential diagnoses included ice water drowning, trauma, profound hypothermia, asystole, prolonged circulatory collapse, systemic hypoxemia with anoxic brain injury, and death.
Investigations
On arrival, a rapid primary survey revealed a cold, flaccid boy without spontaneous respiration or pulse, vomitus on his face and wet snow jacket, and no injuries or sign of struggle. Pupils were small and unreactive. PCO2 was 25 mm Hg. The electrocardiogram was isoelectric. Frothy pink fluid filled the endotracheal tube.
Management
A cervical collar was placed. The child was rapidly prepped with iodine and draped for rapid surgical exposure of femoral vessels as CPR continued. Intravenous heparin (100 units/kg) was given. The right common femoral artery and vein were directly cannulated for venoarterial extracorporeal membrane oxygenation (ECMO). Artificial circulation with ECMO was initiated 18 minutes after arrival. Ipsilateral leg arterial perfusion and venous drainage were then established with an antegrade superficial femoral artery cannula and retrograde distal femoral vein cannula, respectively.
The first recorded esophageal temperature after the initiation of ECMO was 15.2 °C (59 °F). The first gasometric result 26 minutes after initiation of ECMO obtained via α-stat measurement was as follows: pH 7.072, Pco2 35.3 mm Hg, Po2 351 mm Hg, O2 100%, bicarbonate 10.3 mmol/L, base excess −18 mmol/L, ionized calcium 1.2 mmol/L, sodium 141 mmol/L, potassium 5.9 mmol/L, glucose 221 mg/dL, serum lactate >15.0 mmol/L, and international normalized ratio >9.0. The peak serum potassium level 43 minutes after initiation of ECMO was 8.6 mmol/L. The nadir base excess level was −22 mmol/L. Sodium bicarbonate and insulin were administered.
At initiation of ECMO, the boy's rhythm was asystole. The boy was rewarmed with an ECMO heat exchanger-patient gradient ≤10 °C. The target ECMO flow and mean arterial pressure were >125 cc/kg/min and 50 to 60 mm Hg, respectively. As the patient's temperature approached 22 °C (72 °F), low-frequency and low-amplitude sinusoidal electrical deflections were noted on his electrocardiogram. As the patient continued to rewarm, these phasic electrical deflections slowly increased in frequency and amplitude. At approximately 28 °C (82 °F), sinusoidal deflections organized into more classic cardiac electrical activity reminiscent of sinus bradycardia with a wide complex. Amiodarone, calcium gluconate, magnesium sulfate, bolus epinephrine, and epinephrine and norepinephrine infusions were administered. After further rewarming, sinus bradycardia developed and ultimately progressed to normal sinus rhythm with a pulse pressure of 15 mm Hg over ECMO flow.
At 35.5 °C (96 °F), the child was transferred to the pediatric intensive care unit for further management. Significant pulmonary edema and coagulopathy were present. The electroencephalogram demonstrated symmetric 2 to 4 Hz output without epileptiform activity on levetiracetam and low-dose propofol. Spontaneous respirations with ventilator dyssynchrony were noted. Pupils were small and sluggishly reactive. After approximately 10 hours, the boy opened his eyes and turned to painful stimuli and his mother's voice.
On postoperative day 1, the child was transferred to Children's Hospital of Philadelphia per our regional practice for management of children on ECMO. With worsening pulmonary failure and concern for ECMO differential hypoxia syndrome, a right internal jugular vein arterial-inflow cannula was placed. Brain computed tomography demonstrated mild hypoxic changes and small foci of hemorrhagic transformation. The child was decannulated from femoral ECMO and de-escalated to single cannula internal jugular venovenous ECMO. Necrotizing pneumonia required tube thoracostomy. On day 12, the child was decannulated from ECMO. On day 30, he was successfully extubated. Brain magnetic resonance imaging demonstrated early sequelae of hypoxic ischemic changes. The child was alert with spontaneous upper and lower limb movement. Vision, hearing, and swallow function were intact. Higher cognitive function and hypothermic peripheral axonal sensorimotor polyneuropathy slowly improved with time.
Outcome and Follow-Up
On day 59, the boy was discharged to inpatient neurorehabilitation. At 6-month follow-up, he was giving short commands, standing without support, riding a tricycle, eating soft foods, and relearning simple tasks. Peripheral neuromuscular weakness continued to improve.
Discussion
Drowning is a leading cause of pediatric mortality.1 Ice water drowning causes asystolic hypothermia before death. Young and otherwise healthy patients may survive accidental deep hypothermia with prolonged circulatory arrest.1-5 Resuscitation and survival after ice water submersion up to 83 minutes1,2,6 and accidental hypothermia as low as 11.8 °C (53 °F)4,6 are reported. Our patient survived ice water submersion for ≥147 minutes and body temperature that may have been as low as 7 °C (45 °F). This considerably extends the hypothermic circulatory arrest time and temperature nadir from which human life has been rescued.
This case informs clinical and scientific considerations related to limits from which human life may survive. Recovery with meaningful neurologic function is possible after upward of 2.5 hours of asystolic hypothermia with a temperature as low as 7 °C (45 °F). Further scientific and ethical questions arise about decision to rescue, organ preservation, and neuroplasticity after prolonged total-body ischemia.7 These topics are progressively relevant as methods for cryopreservation and thawing of human brain tissue are being developed.8
Drowning submersion time, water temperature, and patient age are prognostic indicators that guide management after drowning. In general, young age is associated with better prognosis.1-3,5,6 Children have a large body surface area to volume ratio and low subcutaneous fat, which contribute to rapid cooling in cold water.4,6,9 If water temperature is >6 °C (43 °F), survival is unlikely for submersion >30 minutes. However, if water is <6 °C (43 °F), survival after >60 minutes of ice water submersion is reported.1,2 As such, current drowning guidelines recommend CPR within 60 minutes of any submersion with unstipulated time extension if water is ice cold.1
The diving reflex and protective effects of cold allow survival after ice water drowning.5 Face immersion in cold water triggers compensatory apnea, bradycardia, and limb and splanchnic vasoconstriction to redistribute cardiac output to the heart and brain and minimize heat loss. The diving reflex deepens until poikilothermia causes asystolic cardiac arrest. Deepening hypothermia further reduces cellular metabolic demand, increases anaerobic metabolism, and shifts the oxygen-hemoglobin dissociation curve leftward. These adaptive responses delay cellular anoxia and amplify end-organ protection after circulatory collapse, most notably neuroprotection—hypothermia increases brain ischemic tolerance by reducing encephaloelectric oxygen demand by 5% to 7% per 1 °C reduction.10 Indeed, cardiac surgeons have routinely used hypothermia for more than half a century in patients on cardiopulmonary bypass.11 Controlled circulatory arrest at 18 °C (64 °F) provides roughly 60 minutes of neuroprotection to safely perform open cardiac or great vessel repair in children and adults.12 With cold in mind, the transport team was instructed not to rewarm the boy.2 Low core temperature minimized his brain oxygen demand and prolonged neuroprotection during CPR until ECMO re-established circulation.
Direct transport to the cardiac operating room facilitated rapid surgical ECMO cannulation. Before the patient arrived, surgical, critical care, anesthesia, perfusion, and nursing teams prepared. This key point facilitated surgical ECMO cannulation within 18 minutes of arrival without interruption of CPR.
The child was rewarmed with a temperature gradient ≤10 °C between patient and heat exchanger. Resuscitation pharmacology is ineffective at low temperature,1 and so resuscitation drugs were held until the core temperature approached 28 °C (82 °F). At 35.5 °C (96 °F), ECMO rewarming was terminated to maintain neuroprotective effects of mild hypothermia after cardiac arrest. Therapeutic hypothermia is controversial but may prevent brain swelling and increased intracranial pressure after circulatory collapse.10
As rescue divers searched for the boy's body, we deliberated whether to attempt resuscitation and likelihood of meaningful neurologic recovery of a child submerged for at least 90 minutes. We reviewed literature for guidance2-4,6 and drew from institutional experience with a 2-year-old submerged in ice water for 40 minutes who received 101 minutes of CPR.3 The toddler recovered with no sequelae. For our current patient, the decision was made to resuscitate and rewarm the boy because of his young age and protective effects of ice water submersion. We reasoned that if meaningful neurologic function were not observed after rewarming, end-organ preservation on ECMO may allow family goodbyes and organ harvest for transplantation to give other sick children the gift of life.9 This important point should be considered by providers faced with the difficult decision to attempt resuscitation of a patient with asystolic hypothermia >90 minutes.
Patients who survive prolonged asystolic hypothermia often exhibit early neurologic deficits that improve with time. Apraxia, ataxia, aphasia, and peripheral axonal sensorimotor polyneuropathy13 are common, even with reassuring brain imaging. Fortunately, many of these patients experience complete or near complete neurologic recovery after neurorehabilitation.1,2,4,6,13 Indeed, our patient exhibited early deficits that improved with time, which highlights posttraumatic neuroplasticity of the pediatric brain.
This boy's rescue was a regional medical effort across 2 health care systems. Many trained and committed interdisciplinary providers cared for him. This is noteworthy in the context of a remarkable case.
Limitations
Peripheral temperature measurement is not as accurate as core temperature measurement. Environmental conditions may influence values, and measurements are less reliable at temperature extremes. As such, the initial 7 °C temperature measurement should be interpreted in the context of a peripheral infrared measurement in a patient with profound hypothermia who was submerged in ice water for more than 2.5 hours.
Conclusions
Survival is possible after upward of 2.5 hours of asystolic hypothermia with a temperature as low as 7 °C (45 °F).
Abbreviations and Acronyms
CPR
=
cardiopulmonary resuscitation
ECMO
=
extracorporeal membrane oxygenation
PCO2
=
partial pressure of carbon dioxide
Acknowledgments
The authors acknowledge and thank the boy's incredibly supportive parents and family; rescue divers Scott and Joey Stoermer; first responders Jim Buckley, and Rodney Decker, EMT; Pennsylvania State Police; Geisinger Emergency Medicine Medical Center providers Jennifer Spinozzi, MD, and Christopher Berry, MD; LifeFlight 1 Robert Frey, Faith Worthington, RN, and Jack Blessee, EMT; operating room/anesthesia Victor Mallory, PA-C, Marcos Awad, MD, Barb Witt, RN, Deborah Miller, RN, Shelby Thomas, RN, Lacee Polly, RN, Anne DeVries, RN, Mark Pohler, MD, Christopher Heiss, CRNA, Erin Arney, CRNA, Shannon Slabinski, CRNA, Christopher Tucker, SRNA, Kurt Erdman, SRNA, Branden Birth, CRNA, Dan Kelly, CRNA, and Kyle Palmer; perfusion Matthew Bauer, RN, Cody Trowbridge, CCP, Douglas Bower, CCP, Shelly Broyan, CCP, Cody Mascho, CCP, and Irina Hilkert; PICU, Richard Lambert, MD, Deborah Lipinski, RPh, Emily Peet, RN, Abigail Medina, RN, Alfia Valdez, RN, Gary Eble, RN, Kalyn Lash, RN, Trisha Hoffman, RN, Joe Mlinarich, RT, Kendra Peachy, RT, and Mary Heddings; pediatric neurology Laufey Sigurdardottir, MD, and Marvin Braun, MD, PhD; LifeFlight 2 Greg Gallerizio, Tyffany Cavanaugh, RN, and Mark Blanchard, EMT; CHOP providers Holly Hendrick, MD, Hera Mahmood, MD, Ryan Morgan, MD, Adam Himebauch, MD, Garrett Keim, MD, and Liz Malick; many other CHOP providers cared for this child. Robert Dowling, MD, PhD (hon), and Miriam Freundt, MD, provided input.
Funding Support and Author Disclosures
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Footnote
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
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