Ilkka Virkkunen

Prehospital therapeutic hypothermia for comatose survivors of cardiac arrest: a randomized controlled trial.

Background: Intravenous infusion of ice‐cold fluid is considered a feasible method to induce mild therapeutic hypothermia in cardiac arrest survivors. However, only one randomized controlled trial evaluating this treatment exists. Furthermore, the implementation rate of prehospital cooling is low. The aim of this study was to evaluate the efficacy and safety of this method in comparison with conventional therapy with spontaneous cooling often observed in prehospital patients.

Induction of therapeutic hypothermia during prehospital CPR using ice-cold intravenous fluid ☆

AIM OF THE STUDY Primarily, to investigate induction of therapeutic hypothermia during prehospital cardiopulmonary resuscitation (CPR) using ice-cold intravenous fluids. Effects on return of spontaneous circulation (ROSC), rate of rearrest, temperature and haemodynamics were assessed. Additionally, the outcome was followed until discharge from hospital. MATERIALS AND METHODS Seventeen adult prehospital patients without obvious external causes for cardiac arrest were included. During CPR and after ROSC, paramedics infused +4 degrees C Ringers acetate aiming at a target temperature of 33 degrees C. RESULTS ROSC was achieved in 13 patients, 11 of whom were admitted to hospital. Their mean initial nasopharyngeal temperature was 35.17+/-0.57 degrees C (95% CI), and their temperature on hospital admission was 33.83+/-0.77 degrees C (-1.34 degrees C, p<0.001). The mean infused volume of cold fluid was 1571+/-517 ml. The rate of rearrest after ROSC was not increased compared to previous reports. Hypotension was observed in five patients. Of the 17 patients, 1 survived to hospital discharge. CONCLUSION Induction of therapeutic hypothermia during prehospital CPR and after ROSC using ice-cold Ringers solution effectively decreased nasopharyngeal temperature. The treatment was easily carried out and well tolerated.

Pulseless electrical activity and unsuccessful out-of-hospital resuscitation: what is the cause of death?

AIMS To study the cause of deaths after witnessed cardiac arrest followed by pulseless electrical activity and unsuccessful of out-of-hospital resuscitation; and to detect any differences between causes of death determined at autopsy and those inferred from clinical history. METHODS In this prospective observational study, data were collected from 91 individuals treated by the emergency medical services in three urban communities in southern Finland. RESULTS Cause of death was determined at autopsy in 59 cases and without autopsy in 32 cases. There were significantly more diagnoses of acute myocardial infarction and fewer of pulmonary embolism and aortic dissection and rupture among cases without autopsy compared with those followed by autopsy. CONCLUSION In unsuccessful resuscitation from out-of-hospital cardiac arrest with pulseless electrical activity as initial rhythm, an autopsy should be performed to determine the correct cause of death.

Prehospital therapeutic hypothermia after cardiac arrest - from current concepts to a future standard

Therapeutic hypothermia has been shown to improve survival and neurological outcome after prehospital cardiac arrest. Existing experimental and clinical evidence supports the notion that delayed cooling results in lesser benefit compared to early induction of mild hypothermia soon after return of spontaneous circulation. Therefore a practical approach would be to initiate cooling already in the prehospital setting.The purpose of this review was to evaluate current clinical studies on prehospital induction of mild hypothermia after cardiac arrest. Most reported studies present data on cooling rates, safety and feasibility of different methods, but are inconclusive as regarding to outcome effects.

Does appropriate treatment of the primary underlying cause of PEA during resuscitation improve patients’ survival?

AIM OF THE STUDY We aimed to document how often patients received appropriate treatment of the primary cause underlying pulseless electrical activity (PEA) during cardiopulmonary resuscitation (CPR) and how it affected their outcome. METHODS Data were collected between 2003 and 2010 in Finland and Sweden. All adult patients who underwent in-hospital cardiac arrest (IHCA) with PEA as the initial rhythm were included, if CPR was attempted. Patients were divided into two groups: those who received appropriate treatment of the primary cause during CPR (treatment of the primary cause group) and those who received conventional CPR (non-specific treatment group). Survival between groups was compared and a multivariable logistic regression analysis was performed to exclude the effect of possible confounders. RESULTS Of 104 study patients, 19 (18%) received treatment of the primary cause and 85 (82%) received non-specific treatment. 30-Days survival of patients in treatment of primary cause group was superior compared to patients in the non-specific treatment group: 6 (32%) vs. 9 (11%) were alive 30 days after IHCA, p=0.03. Multivariable analysis suggested that treatment of the primary cause improves the odds of survival 2.5-fold, but this was not statistically significant. Age was the only significant independent prognostic factor for 30-days survival. CONCLUSION During CPR, only a fifth of patients received appropriate treatment of the primary cause underlying PEA. Those patients were more likely to be alive 30 days after IHCA, but age turned out to be the only significant individual factor for better survival.

Conduct of emergency research in patients unable to give consent—Experiences and perceptions of patients, their consent providing next of kin, and treating physicians following a prehospital resuscitation trial☆

OBJECTIVE According to a directive of the European Parliament, informed consent is required to conduct a clinical trial also in emergencies when the patient is unable to provide consent. In these cases surrogate consent can be obtained from the patients next of kin. There are no reports describing how patients and their next of kin perceive this policy. The perceptions of patients and their spouses involved in an emergency trial conducted under surrogate consent were surveyed. METHODS A survey was sent to survivors of prehospital cardiac arrest, to consent providers regardless of patient outcome, and to physicians who had recruited the patients. RESULTS 11 (92%) patients, 17 (68%) consent providers, and all physicians returned the survey. All held a positive attitude towards emergency research and were willing to participate without own consent in a trial approved by an institutional review board (IRB). Opinions among responding groups were similar albeit a significant difference regarding the perceived capability of the consent provider to decide upon patients enrolment. Spouses felt able to provide consent, but physicians were sceptical of this. Patients and their spouses would have appreciated additional information regarding the index trial after the acute phase. CONCLUSIONS Emergency research was perceived positively by cardiac arrest victims and their spouses previously involved in a resuscitation trial. Possible own participation in an emergency trial without personal consent was considered acceptable. Patients and their spouses would prefer additional research information after enrolment.

Hypothermic preconditioning of donor organs prior to harvesting and ischaemia using ice-cold intravenous fluids

To promote organ transplantation and viability, hypothermia has been applied as a protective agent for decades. Current management of organ preservation includes hypothermia as a component of static storage. In rare cases, hypothermic perfusion is initiated in the donor organs prior to harvesting but this requires invasive perfusion techniques. Therefore, hypothermic organ protection is currently achieved only after organ retrieval and onset of ischaemic injury cascades. The relevant mechanisms of cellular and organ damage involve ischaemia-reperfusion injury and apoptosis. In this hypothesis, we propose the possibility of inducing hypothermic protective effects prior to organ harvesting using infusion of ice-cold (+4 degrees C) intravenous fluid in the organ donor. This method of cooling to mild hypothermia (32-34 degrees C) has been found feasible in e.g. cardiac arrest victims and already during the ischaemic insult. We hypothesize that cooling with ice-cold fluid preceding organ harvesting would downregulate organ metabolism and oxygen consumption resulting in improved tolerance to ischaemia. Furthermore, according to existing evidence, mild hypothermia possesses anti-apoptotic effects and suppresses reperfusion associated inflammatory response. Finally, diabetes insipidus is often observed in the brain dead donor. Subsequent hypovolemia is conveniently treated with additional infusion of cold intravenous fluid. We offer this hypothesis as a simple method of improving donor organ viability via improved tolerance to ischaemia and reperfusion injury. This method of hypothermic preconditioning seems safe, inexpensive and easily applicable in virtually every institution treating organ donors. The feasibility and effects of this hypothesis could be further evaluated in comparison to current treatment protocols in laboratory settings including evaluation of organ preservation.

Statins for post resuscitation syndrome.

After sudden cardiac arrest, successful resuscitation and return of spontaneous circulation, a multi-faceted ischaemia/reperfusion related disorder develops. This condition now known as post resuscitation syndrome is characterised by marked increases in the inflammatory response and changes in coagulation profile and vascular reactivity. Additionally, the production of reactive oxygen species and activation of cytotoxic cascades of metabolism add to these injury mechanisms resulting in multiorgan perfusion deficits and dysfunction. Especially in the cerebrum these injuries may be the cause of significant morbidity and mortality. Recent evidence has shown that statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) exert numerous beneficial effects in cardiovascular diseases irrespective of the lipid status. Remarkably, these pleiotropic effects seem to extended beyond cardiovascular diseases such as immunomodulative and antioxidative properties. We hypothesised that administration of statins early in the post resuscitation phase would prove beneficial in the resuscitated patient via several pleiotropic effects. These include inhibition of excessive coagulation and inflammatory response, suppression of oxygen radical production and improved vascular reactivity. The discussed effects are mediated via multiple pathways activated in the cardiac arrest victim, to which statins have been shown to have a beneficial modulating effect in experimental settings and non-cardiac arrest patients. To test this hypothesis in clinical practice, a randomized, controlled trial with sufficient power and standardised post resuscitation treatment would be necessary. The generally good tolerance of statin therapy with minimal adverse effects would support this experiment, although a parenteral form of the drug to ensure adequate dosage might be a prerequisite.

Pulseless electrical activity and successful out-of-hospital resuscitation – long-term survival and quality of life: an observational cohort study

BackgroundThe aim of the study was to evaluate the long-term outcome of patients successfully resuscitated from pre-hospital cardiac arrest with initial pulseless electrical activity (PEA), because the long-term outcome of these patients is unknown. Survival, neurological status one year after cardiac arrest and self-perceived quality of life after five years were assessed.MethodsThis retrospective study included adult patients resuscitated from PEA between August 2001 and March 2003 in three urban areas in southern Finland. A validated questionnaire was sent to patients while neurological status according to the Cerebral Performance Category (CPC) -classification was assessed based on medical database notes recorded during follow-up evaluations.ResultsOut of 99 included patients in whom resuscitation was attempted, 41 (41%) were successfully resuscitated and admitted to hospital. Ten (10%) patients were discharged from hospital. Seven were alive after one year and six after five years following cardiac arrest. Five of the seven patients alive one year after resuscitation presented with the same functional level as prior to cardiac arrest.ConclusionsPatients with initial PEA have been considered to have poor prognosis, but in our material, half of those who survived to hospital discharge were still alive after 5 years. Their self-assessed quality of life seems to be good with only mild to moderate impairments in activities of daily life.

Assessment of futility in out‐of‐hospital cardiac arrest

Our aim was to evaluate the impact of futile resuscitation attempts to the outcome calculations of attempted resuscitation in out‐of‐hospital cardiac arrest (OHCA). Defined as partial resuscitations, we focused on a subgroup of patients in whom cardiopulmonary resuscitation (CPR) was initiated, but further efforts were soon abandoned due to evidence of futility.