Elsevier

Resuscitation

Volume 62, Issue 2, August 2004, Pages 143-150
Resuscitation

A prospective, multicenter pilot study to evaluate the feasibility and safety of using the CoolGard™ System and Icy™ catheter following cardiac arrest

https://doi.org/10.1016/j.resuscitation.2004.02.016Get rights and content

Abstract

Background: Cardiac arrest causes devastating neurological morbidity and mortality. Mild/moderate hypothermia is neuroprotective after global cerebral ischemia. More rapid controlled attainment of the target temperature may increase efficacy. Methods: We assessed the safety and feasibility of endovascular cooling in a single arm study of comatose patients who had been successfully resuscitated after cardiac arrest. Core temperature was reduced to a target of 33 °C for 24 h using a closed loop endovascular system placed in the inferior vena cava, followed by controlled rewarming. Primary outcomes were speed and accuracy of cooling, survival and GOS after 30 days. Results: Thirteen patients were enrolled, six male, age 60±19 years. Time from cardiac arrest to return of spontaneous circulation was 14.3 min (range 5–32.5). It took 3 h and 39 min (median 210 min, IQ 80–315) to reach 33 °C; cooling averaged 0.8±0.3 °C/h (range 0.22–1.12 °C/h). Temperature was tightly maintained for all patients averaging 32.7±0.5 °C. Rewarming lasted 18.3±5.9 h. Five patients (38%) had 30-day Glasgow Outcome Scores of 1–2. Four patients died, none related to the hypothermia procedure. No unanticipated or procedure-related adverse events occurred. Conclusion: In comatose survivors of cardiac arrest, hypothermia via endovascular methods is safe and feasible, and target temperatures can be achieved and controlled rapidly and precisely. More studies are needed to assess the efficacy of rapid endovascular hypothermia after cardiac arrest.

Sumàrio

Contexto: A paragem cardı́aca causa morbilidade e mortalidade neurológicas devastantes. A hipotermia ligeira a moderada é neuroprotectora após isquemia cerebral global. A obtenção mais rápida e controlada da temperatura pretendida pode aumentar a eficácia. Métodos: Avaliámos a segurança e exequibilidade do arrefecimento endovascular num estudo com um único grupo de doentes comatosos que foram reanimados com sucesso após paragem cardı́aca. A temperatura central foi reduzida até 33 °C durante 24 h utilizando um sistema de arrefecimento endovascular em ansa colocado na veia cava inferior, seguido de reaquecimento controlado. Os outcomes primários foram velocidade e precisão do arrefecimento, sobrevivência e GCS após 30 dias. Resultados: Foram incluı́dos no estudo 13 doentes, seis homens, de idades 60 ± 19 Anos. O tempo desde a paragem cardı́aca até à recuperação da circulação espontânea foi de 14.3 min. (média 5–32.5). Foram necessárias 3 h e 39 min (mediana 210 min, IQ 80–315) para obter 33 °C; arrefecimento médio 0.8 ± 0.3 °C/h (média 0.22–1.12 °C/h). A temperatura foi mantida com rigor em todos os doentes com média de 32.7 ± 0.5 °C. O reaquecimento durou 18.3 ± 5.9 h. Cinco doentes (38%) tinham uma Glasgow Outcome Score (GOS) de 1–2. Quatro doentes morreram, nenhuma das mortes foi relacionada com a hipotermia. Não ocorreram quaisquer eventos não antecipáveis ou adversos relacionados com o procedimento. Conclusões: Nos comatosos sobreviventes de paragem cardı́aca, a hipotermia pelo método endovascular é segura e exequı́vel, e podem ser obtidas e controladas rapidamente e de forma precisa as temperaturas alvo. São necessários mais estudos para avaliar a eficácia da hipotermia endovascular rápida após paragem cardı́aca.

Resumen

Antecedentes: El paro cardiorrespiratorio causa morbilidad y mortalidad devastadora. La hipotermia leve/moderada es neuroprotectora después de isquemia cerebral global. La más rápida obtención controlada de la meta de temperatura puede aumentar la eficacia. Métodos: Evaluamos la seguridad y factibilidad del enfriamiento endovascular en un estudio de una etapa en pacientes comatosos que han sido resucitados exitosamente después de un paro cardı́aco. La temperatura central se redujo hasta una meta de 33 °C por 24 horas usando un sistema endovascular de asa cerrada localizado en el interior de la vena cava inferior, seguido por recalentamiento controlado. Los resultados primarios fueron enfriamiento rápido y preciso, sobrevida y GOS después de 30 dı́as. Resultados: Se enrolaron 13 pacientes, 6 varones, edad 60±19 años. El tiempo desde el paro cardı́aco hasta el retorno a circulación espontánea fue de 14.3 minutos (rango 5–32.5). Tomó 3 h y 39 min (mediana 210 min, IQ 80–315) para alcanzar los 33 °C; el enfriamiento promedió 0.8±0.3 °C/h(rango 0.22–1.12 °C/h). La temperatura fue mantenida estrechamente en todos los pacientes promediando 32.7±0.5 °C. El recalentamiento duró 18.3±5.9 h. Cinco pacientes (38%) tuvieron puntajes de resultados de Glasgow (GOS) de 1–2. Cuatro pacientes murieron, ninguno con relación al proceso de la hipotermia. No ocurrieron eventos no anticipados ni efectos adversos relacionados con el procedimiento. Conclusión: En sobrevivientes comatosos de paro cardı́aco, la hipotermia por método endovascular es segura y factible, y las metas de temperatura se pueden alcanzar y controlar en forma rápida y precisa. Son necesarios más estudios para evaluar la eficacia de la hipotermia endovascular rápida después de un paro cardı́aco.

Introduction

Each year there are at least 300,000 sudden cardiac deaths in the United States [1]. Of these, nearly 70% occur outside the hospital [2]. As many as 20% of patients will survive an out-of-hospital cardiac arrest [3], [4] although considerably lower numbers have been reported [5], [6], and substantially higher (∼40%) rates have been achieved with the advent of automated external defibrillation [7]. Survival after an in-hospital cardiac arrest is even less certain [8], [9], [10].

Most patients who do not awaken after cardiac arrest will die. Many of those who survive are left with enduring and devastating neurological deficits due to global cerebral ischemia [11], [12]. In recent placebo controlled trials [13], [14], survival with poor neurological outcome occurred in 6–11%.

For successful resuscitation, it is not only important to stop cardiac ischemia as quickly as possible but also to overcome post-resuscitation tissue injury [15], [16], [17]. The ability of tissue to survive anoxic no-flow states is reduced in normothermia compared with hypothermia [17], [18]. Clinical and experimental studies suggest a pronounced protective effect of hypothermia, especially in models of global forebrain ischemia mimicking the cerebral consequences of cardiac arrest [13], [14], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30].

To date only systemic external hypothermia has been shown to be efficacious as a neuroprotectant after global cerebral ischemia in humans. The procedure is laborious and time intensive. Average or median times to achieve cooling to 33 °C using external cooling devices has been 480 min [14], 287 min [29], and 301 min [30] in recent studies. Experimentally, rapid attainment of the target temperature may be more beneficial and offer better neuroprotection than slow cooling [31].

Endovascular methods of cooling may provide rapid cooling and temperature control for use in cardiac arrest patients. One such system has been developed by the Alsius Corporation (Irvine, CA, USA), where cooled saline solution is pumped through an intravascular heat exchange catheter placed in the inferior vena cava via femoral vein. We undertook this trial to assess the safety and feasibility of using this system for endovascular cooling after cardiac arrest. We also aimed to assess the speed of endovascular-induced hypothermia and the ability of the endovascular cooling method to maintain hypothermia within a tight range.

Section snippets

Study design and patient selection

This was a prospective, non-randomized, three clinical center trial performed in the United States, between March 2001 and September 2002, in which patients who had been successfully resuscitated following primary cardiac arrest, but had not regained consciousness (GCS≤8), were treated with moderate hypothermia induced by the CoolGard™ System with the Icy™ catheter. Patients were enrolled in the study when the following criteria were met: 18 years of age or older, suspicion of primary cardiac

Patients

A total of 13 patients were enrolled in this study; six males and seven females with a mean age of 60.2±18.7 years (range 32–83 years). “Down time”, was defined as the interval between onset of cardiac arrest and return of spontaneous circulation (pulse). When the recorded down time was imprecise (e.g. 15–20 min), the mean value between the two extremes given was used (in above example, 17.5 min). The average estimated down time was 14.3 min, with down time not reported for one subject. Down time

Discussion

After several positive pilot studies using moderate hypothermia (33–34 °C) following cardiac arrest in humans were reported [26], [27], [28], [30], Bernard et al. in an Australian study [13] confirmed in 77 randomized patients a significant benefit in favor of hypothermia. The Hypothermia After Cardiac Arrest Study Group [14], studying 275 patients in a randomized controlled trial, also showed significant improvements in neurologic outcome and mortality 6 months later. Based on these results,

Acknowledgements

Dr. Al-Senani was supported by NIH Training Grant NS007412. This study was funded by the Alsius Corporation. Study concept, design, monitoring, data analysis, and manuscript preparation were a cooperative effort between Alsius and the investigators. Drs. Grotta, Graffagnino, and Chung receive consulting fees from Alsius. Drs. Palmer and Collins are employees of Alsius.

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