The utilization of post-resuscitation therapeutic hypothermia (TH)for non-neurologically intact adult patients after ventricular fibrillation (V-fib) arrest is supported by the literature and is becoming more common.[1-6] TH is less commonly used in other situations that have resulted in anoxic insult, due in large part to lack of clear evidence from clinical trials.
For example, it seems logical that provision of TH for patients who have suffered traumatic brain injury (TBI) would be beneficial, but many of the trials have demonstrated no benefit.[7-9] The optimal time to initiate TH, the appropriate duration of TH, and other issues concerning previous study design for patients with TBI have prompted another clinical trial that is currently underway.[10,11]
Perhaps in no area is proper use of TH less clear than in pediatrics, where essentially no trials have evaluated the use of hypothermia except in the neonatal period. A recent survey of pediatric intensivists revealed that only 9% use TH "all the time" for post-arrest pediatric patients and 38% use it "some of the time," demonstrating the difficulties in making treatment decisions without clinical trials.
Since initiating the prehospital TH program at Wake County EMS in October 2006, we have induced more than 300 patients and have encountered many atypical post-arrest patients, including pediatrics, drownings and electrocutions. Two case reports are discussed below as examples of the challenges associated with these patients.
Case 1: A 5-Year-Old with "Simple" Gastroenteritis
A previously healthy 5-year-old male was noted to have malaise, nausea and vomiting and was taken by private vehicle to his pediatrician. Anti-emetics were provided, and the patient improved. He was able to take liquids by mouth and was taken back home. Later that day, he was noticed to have a decreased level of consciousness, and EMS was summoned.
Fire first responders found the patient to have faint brachial pulses and a respiratory rate of 4. Respirations were assisted with a bag-valve mask (BVM) with good success. Paramedics arrived to find the patient with good air movement with the BVM as well as a sinus rhythm on the monitor at 130 bpm with weak brachial pulses.
While transferring the patient to the ambulance, he suffered bradycardic PEA arrest with a rate on the cardiac monitor of < 20 bpm and no palpable pulses. Compressions were initiated, and in the next 15 minutes, epinephrine and atropine were provided, BVM ventilations were continued, and his blood glucose was found to be 15. Dextrose was administered, and the level was corrected to 274.
The patient achieved return of spontaneous circulation (ROSC) after 15 minutes of resuscitative efforts. EMS providers bypassed two nearer hospitals (total transport time 20 minutes, 41 seconds) in order to transport the patient to an appropriate pediatric post-resuscitation care facility.
The patient presented to the pediatric emergency department (ED) with a heart rate of 152, a blood pressure of 74/29 and no purposeful neurologic activity. The patient suffered two additional episodes of arrest with both PEA and V-fib, each lasting approximately five minutes. The serum sodium was found to be markedly low and the potassium greater than 7.0. The working diagnosis was of acute adrenal insufficiency, and the patient was finally stabilized after 25 total minutes of pulselessness with use of IV stress dose steroids, defibrillation and treatment of the hyperkalemia.
The patient then was cooled to 33° with an endovascular device and maintained at that temperature for 24 hours. After 14 days of ICU care, the patient ate his first meal and was discharged home 19 days after the event. He has made a complete neurologic recovery and is being treated and monitored for his rare adrenal insufficiency that was exacerbated by a simple viral illness.
Case 2: A Shocking Day at Work
A 33-year-old male was working on a construction site when he accidentally cut into a power cable at a junction box. Tetany (involuntary contraction of muscles) ensued, and a swift thinking co-worker pulled the patient from the electrical source by his rubber boots. First responders provided compressions, and the patient was subsequently found to be in V-fib. He was defibrillated twice at 360J, and the airway was rapidly managed with a blind insertion airway device (BIAD). One milligram of epinephrine was given via the intraosseous route, and the patient subsequently achieved ROSC. His total time of pulselessness was estimated at 20 minutes.
The patient presented to the ED of a designated post-resuscitation facility with a blood pressure of 116/63, a sinus rhythm of 89 and some spontaneous respiratory effort. No purposeful response to pain was noted. Subsequently, there was concern regarding whether the patient had suffered internal injuries from the electrocution. Trauma and burn specialists were consulted. The patient had no elevation of his serum creatinine kinase, normal renal function and no myoglobin in his urine. This case was then considered as a V-fib arrest, and the patient was cooled intravascularly to 33° for 24 hours and re-warmed over 12 hours. He has made a complete neurologic recovery.
As the use of TH continues to become more common, EMS providers, medical directors, emergency physicians and hospital-based physicians will encounter challenges regarding the management of atypical patients. Ideally, randomized controlled trials could be utilized to evaluate treatment options. Such evidence is not available for many of the conditions encountered, so we are left to extrapolate from the data that are available. The cases presented are certainly not intended to address whether or not TH should be utilized in all pediatric or electrocution cases but rather to demonstrate that use in such cases is feasible and share the challenges so that we all may be better prepared to treat these atypical patients.
Disclosure: The author has received no monetary support from the sponsors of this supplement. His EMS system has received support from Philips in the form of equipment for evaluation and research purposes.