Researchers may have developed a way to potentially assist prognostication in the first 24 hours after out-of-hospital cardiac arrest (OHCA) when patients are still in a coma. Their findings are revealed today at Acute Cardiovascular Care 2014 by Dr Jakob Hartvig Thomsen from Copenhagen, Denmark.
Acute Cardiovascular Care is the annual meeting of the Acute Cardiovascular Care Association (ACCA) of the European Society of Cardiology (ESC) and takes place 18-20 October in Geneva, Switzerland.
Dr Thomsen said: "When we talk to relatives and friends immediately after a cardiac arrest we often tell them that we're not able to say much about the prognosis for their Dad, Mom, friend, etc, for the next 3 to 4 days. This is incredibly distressing and loved ones are desperate for more information."
He added: "Therapeutic hypothermia is used in comatose survivors of OHCA to protect them from brain damage. Current recommendations say that prognostication should not be made until 72 hours after hypothermia when patients have returned to normothermia and the sedation has worn off.1 The prognostic tools presently available are not reliable until after this 72 hour period."
Dr Thomsen continued: "During hypothermia some patients lower their heart rate, which is called bradycardia. We hypothesised that this is a normal physiological reaction and that these patients may have less severe brain injury after their arrest and therefore lower mortality."
The study was conducted in the intensive care unit at Copenhagen University Hospital during 2004-2010 and was supported by the EU Interreg IV A programme. It included 234 comatose survivors of OHCA who underwent the hospital's standard 24 hour therapeutic hypothermia protocol. Heart rhythm was measured hourly and sinus bradycardia (defined as less than 50 heart beats per minute) was used to stratify the patients. The primary endpoint was 180 day mortality.
The investigators found that patients who experienced sinus bradycardia during therapeutic hypothermia had a 17% 180 day mortality rate compared to 38% in those with no sinus bradycardia (p<0.001) (figure 1), with a hazard ratio (HR) of 0.38. Sinus bradycardia during therapeutic hypothermia remained an independent predictor of lower 180 day mortality with a HR of 0.51 after adjusting for known confounding factors including sex, age, comorbidity, witnessed arrest and bystander CPR.
Dr Thomsen said: "Patients with sinus bradycardia during therapeutic hypothermia had a 50-60% lower mortality rate at 180 days than those with no sinus bradycardia. We also found that sinus bradycardia was directly associated with a better neurological status 180 days after the arrest."
Few patients are in sinus bradycardia when they arrive at the intensive care unit (a period called the induction phase). However the proportion rises during hypothermia to almost 50%, and then declines during the rewarming phase.
Dr Thomsen said: "We speculated that this proportion of patients who develop sinus bradycardia during hypothermia would have better brain function and a lower mortality rate, and that was what we found. "
He added: "Now when we observe that a patient experiences sinus bradycardia below 50 beats per minute within the first 24 hours we can tell families that their relative may have a chance of recovery."
Dr Thomsen continued: "There is a lot of discussion about defining criteria to identify patients we should stop treating when a vegetative state is inevitable. We shouldn't give up on patients who still have a chance so this is an area in which we need to be very certain. Our findings provide an early marker of patients who may do well. Hopefully in the future, together with other tools, we will be able to differentiate between those with a very good or very poor prognosis so we can prioritise intensive care resources."
He concluded: "We are currently validating our findings by conducting the same analysis in the 950 patients included in the Targeted Temperature Management trial which was conducted in 36 intensive care units."
Jacqueline Partarrieu | Eurek Alert!
Finnish research group discovers a new immune system regulator
23.02.2018 | University of Turku
Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy