Effect of hypothermia therapy after outpatient cardiac arrest due to ventricular fibrillation

Therapeutic temperature management after cardiac arrest and the risk of bleeding: systematic review and meta-analysis

AIM

Prognosis after cardiac arrest in the era of modern critical care is still poor with a high mortality of approximately 90%. Around 30% of the survivors have neurological impairments. Targeted temperature management (TTM) is the only treatment option which can improve mortality and neurological outcome. It is so far unclear if bleeding complications occur more often in patients undergoing TTM treatment.

METHODS

We conducted a systematic literature research in September 2013 including three major databases i.e. MEDLINE, EMBASE and CENTRAL. All studies were rated in respect to the ILCOR Guidelines and concerning their level of evidence and quality. We then performed a meta-analysis on bleeding disposition under TTM.

RESULTS

We initially found 941 studies out of which 34 matched our requirements and were thus included in our overview. Five studies including 599 patients were summarized in a meta-analysis concerning bleeding complications of all severities. There was a trend toward higher bleeding in patients treated with TTM (RR: 1.30, 95% CI: 0.97-1.74) which did not reach significance (p=0.085). Seven studies with an overall 599 patients were included in our meta-analysis on bleeding requiring transfusion. There was no significant difference in the incidence of severe bleeding with a risk ratio of 0.97 (95% CI: 0.61-1.56, p=0.909).

CONCLUSIONS

The data included in our meta-analysis indicate that, concerning the risk of bleeding, TTM is a safe method for patients after cardiac arrest. We did not observe a significantly higher risk for bleeding in patients undergoing TTM.

Successful treatment of a young woman with acute complicated myocardial infarction

Therapeutic hypothermia is method used to improve the neurological status of patients who are at risk of ischaemia after myocardial infarction. We report a case of a 28-year-old woman who suffered acute myocardial infarction complicated by ventricular fibrillation. The patient was successfully resuscitated. Invasive and non-invasive medical treatment was applied including therapeutic hypothermia. Success was achieved due to adequate public reaction, fast transportation, blood vessel revascularization and application of therapeutic hypothermia. The patient was successfully discharged after one week of treatment, and just minor changes in heart function were present.

Therapeutic strategy using extracorporeal life support, including appropriate indication, management, limitation and timing of switch to ventricular assist device in patients with acute myocardial infarction

The appropriate indication for, management of and limitations to extracorporeal life support (ECLS) and the timing of a switch to a ventricular assist device (VAD) remain controversial issues in patients with acute myocardial infarction (AMI) complicated with cardiogenic shock or cardiopulmonary arrest. To evaluate and discuss these issues, we studied patients with AMI treated with ECLS and compared deceased and discharged patients. Thirty-eight patients with AMI who needed ECLS [35 men (92.1 %), aged 59.9 ± 13.5 years] were enrolled in this study. Of these 38 patients, 34 subsequently underwent percutaneous coronary intervention (PCI), and four subsequently received coronary artery bypass grafting (CABG). Fourteen patients (36.8 %) were discharged from the hospital. The outcome was not favorable for those patients with deteriorating low output syndrome (LOS) and the development of leg ischemia, hemolysis and multiple organ failure during ECLS. Levels of creatine kinase, creatine kinase-MB (CK-MB), lactate dehydrogenase, serum creatinine (Cr) and amylase after the patient had been put on ECLS and fluctuation of the cardiac index, blood pressure, arterial blood gas analysis and CK-MB and Cr levels during ECLS were indicators to switch from the ECLS to VAD. In the case of patients with no complication associated with ECLS, 4.6-5.6 days after initiation of ECLS was assumed to be the threshold to decide whether to switch from ECLS to VAD. Patients with AMI who suddenly developed refractory pulseless ventricular tachycardia or ventricular fibrillation without deteriorating LOS and who underwent successful PCI or CABG, and who prevented the complications associated with ECLS, showed a high probability of recovering with ECLS.

Report from J-PULSE multicenter registry of patients with shock-resistant out-of-hospital cardiac arrest treated with nifekalant hydrochloride

BACKGROUND

Nifekalant hydrochloride (NIF) is an intravenous class-III antiarrhythmic agent that purely blocks the K(+)-channel without inhibiting β-adrenergic receptors. The present study was designed to investigate the feasibility of NIF as a life-saving therapy for out-of-hospital ventricular fibrillation (VF).

METHODS AND RESULTS

The Japanese Population-based Utstein-style study with basic and advanced Life Support Education study was a multi-center registry study with 4 participating institutes located at the northern urban area of Osaka, Japan. Eligible patients were those treated with NIF because of out-of-hospital VF refractory to 3 or more precordial shocks and intravenous epinephrine. Between February 2006 and February 2007, 17 patients were enrolled for the study. The time from a call for emergency medical service to the first shock was 12(6-26)min. The time from the first shock to the NIF administration was 25.5(9-264)min and the usage dose of NIF was 25(15-210)mg. When excluding 3 patients in whom percutaneous extracorporeal membrane oxygenation was applied before NIF administration, the rate of return of spontaneous circulation was 86% and the rate of admission alive to the hospital was 79%. One patient developed torsade de pointes.

CONCLUSIONS

Intravenous administration of NIF seems to be feasible as a potential therapy for advanced cardiac life-support in patients with out-of-hospital VF, and therefore further study is warranted.

Contemporary practices in postcardiac arrest syndrome: the role of mild therapeutic hypothermia

Out-of-hospital cardiac arrest remains a major cause of mortality and morbidity despite progress in resuscitative practices. The number of survivors with severe neurological impairment at hospital discharge is similarly dismal. Recently, much attention has been directed toward the use of mild therapeutic hypothermia in the care of comatose survivors with postcardiac arrest syndrome. Recent research suggests mild hypothermia lowers mortality and improves neurological outcome after successful treatment of cardiac arrest. The current 2005 updated guidelines of International Liaison Committee on Resuscitation and European Resuscitation Council recommend the utilization of mild induced hypothermia in postresuscitation treatment. Hypothermia induction in order to avoid the pathophysiological mechanisms of euthermia and hyperthermia and subsequent complications are briefly discussed. Cooling methods, potential side effects and questions regarding implementation of therapeutic hypothermia recommendations in every day clinical practice and future investigation are also addressed.

Anesthesia and analgesia protocol during therapeutic hypothermia after cardiac arrest: a systematic review

BACKGROUND

Present practice guidelines recommend sedative-analgesic and neuromuscular blocking administration during therapeutic hypothermia in comatose patients after cardiac arrest. However, none suggests the best administration protocol. In this study, we evaluated intensivists' preferences regarding administration.

METHODS

A systematic literature review was conducted to identify clinical studies published between 1997 and July 2009. Selected articles had to meet the following criteria: use of hypothermia to improve neurologic outcome after cardiac arrest, and specific mention of the sedative protocol used. We checked drugs and dose used, the reason for their administration, and the specific type of neurologic and neuromuscular monitoring used.

RESULTS

We identified 44 studies reporting protocols used in 68 intensive care units (ICUs) from various countries. Midazolam, the sedative used most often, was used in 39 ICUs at doses between 5 mg/h and 0.3 mg/kg/h. Propofol was used in 13 ICUs at doses up to 6 mg/kg/h. Eighteen ICUs (26%) did not report using any analgesic. Fentanyl was the analgesic used the most, in 33 ICUs, at doses between 0.5 and 10 microg/kg/h, followed by morphine in 4 ICUs. Neuromuscular blocking drugs were routinely used to prevent shivering in 54 ICUs and to treat shivering in 8; in 1 ICU, their use was discouraged. Pancuronium was used the most, in 24 ICUs, followed by cisatracurium in 14. Four ICUs used neuromuscular blocking drug administration guided by train-of-four monitoring and 3 ICUs used continuous monitoring of cerebral activity.

CONCLUSIONS

There is great variability in the protocols used for anesthesia and analgesia during therapeutic hypothermia. Very often, the drug and the dose used do not seem the most appropriate. Only 3 ICUs routinely used electroencephalographic monitoring during paralysis. It is necessary to reach a consensus on how to treat this critical care population.