Clinical paperModerate hypothermia for severe cardiogenic shock (COOL Shock Study I & II)☆
Introduction
Hypothermia has become an established therapeutic concept in the treatment of cardiovascular and neurological diseases. First routinely used in patients undergoing open heart surgery1 and neurosurgery,2 moderate hypothermia has meanwhile been shown to exhibit considerable protection from hypoxaemic brain injury after circulatory arrest.3, 4
While feasibility of moderate hypothermia in patients has been proven, there is still some debate about the haemodynamic side effects of hypothermia. Especially in patients with reduced left-ventricular function or even cardiogenic shock potentially detrimental effects of hypothermia have been discussed,5 since hypothermia has been observed to decrease cardiac output in healthy animals.6, 7 In consequence, earlier ILCOR and resuscitation guidelines have recommended not to use hypothermia in patients with out-of-hospital cardiac arrest and cardiogenic shock.5 However, current registries demonstrate that after cardiac arrest and resuscitation inotropes and/or vasopressors were administered to 77% of patients, and 18% of patients needed further inotropic drugs, vasopressors and/or intra-aortic balloon counter pulsation.8
We could previously show in animal experiments and isolated human cardiac muscle that moderate hypothermia exerts calcium-independent positive inotropic effects.7, 9 Thus, we tested the hypothesis that moderate hypothermia is safe to apply and improves cardiac contractile function in patients in cardiogenic shock.
Section snippets
Study design
The study was designed as a prospective, unblinded intervention trial where patients served as their own controls. The study protocol was approved by the ethics committee of the University of Göttingen. The study was carried out in accordance with the Declaration of Helsinki of the World Medical Association and its amendments10 and European Union guidelines for good clinical practice11 and was led independently of the sponsor. All patients or their immediate relatives, where necessary, gave
Acute effects of cooling on clinical, laboratory and haemodynamic parameters in cardiogenic shock
Moderate hypothermia (33.1 ± 0.1 °C) was reliably achieved in all patients of COOL Shock I, in average within 183 ± 27 min (Table 2). Cooling and moderate hypothermia had no short-term effects on haemoglobin, serum potassium, creatinine and lactate and did not affect global oxygen supply or consumption. In addition, cooling did not change electrocardiographic parameters such as the PQ or the QTc interval (Table 2).
Fig. 2 shows a typical haemodynamic response to cooling, hypothermia, and re-warming in
Discussion
The first major finding of the present study is that the induction of moderate hypothermia up to 24 h is feasible and safe for patients in cardiogenic shock, i.e. the worst condition of acute and chronic heart disease.
This is of crucial interest, since hypothermia has been shown to be the most effective therapeutic intervention to reduce neurological dysfunction and mortality in survivors of cardiac arrest, while at the same time cardiac arrest is in most cases secondary to pre-existing cardiac
Conflicts of interest
None declared.
Acknowledgement
Heat exchange balloon catheters, temperature probes and the cooling system were provided by Radiant Medical.
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2017, International Journal of CardiologyCitation Excerpt :We screened consecutive patients admitted to our Hospital for out-of-hospital cardiac arrest in order to perform an emergency coronary angiography with primary PCI and who received therapeutic hypothermia (HT group). Patients with out-of-hospital cardiac arrest and cardiogenic shock are usually treated by hypothermia in our institution, as previously shown in several studies [8–10]. As ethical committee considers hypothermia as standard of care in these patients, randomization of these patients to hypothermia or not was not allowed.
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2015, Best Practice and Research: Clinical AnaesthesiologyCitation Excerpt :While induced hypothermia has become the standard of care for many CA patients, the present guidelines do not make any explicit recommendations for patients in shock, as shock was an exclusion criterion in previous randomized trials [24]. Recent studies have shown that induced hypothermia improves hemodynamics and may reduce mortality in cardiogenic shock [36–38]. The recently published Target Temperature Management trial (TTM trial) found no differences in mortality or in the composite of poor neurologic function or death between an intervention of 33 and 36 °C.
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A Spanish translated version of the summary of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2012.09.034.
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These authors contributed equally to this work.