Muscle relaxants are a necessary part of anesthesia during certain major operations. Studies have, however, hinted at respiratory risks connected with these drugs. POPULAR, a major prospective observational European study supported by the European Society of Anaesthesiology (ESA) and led by the Technical University of Munich (TUM), has confirmed the association between use of muscle relaxants and respiratory complications and assessed the chances of the current avoidance strategies.
Anesthetics make patients unconscious during an operation and prevent them from feeling pain. Muscles, however, are not paralyzed by these drugs and may still move. “To prevent this, we also use muscle relaxants or, more precisely, neuromuscular blocking agents,” says Professor Manfred Blobner, an anesthesiologist at TUM's Clinic for Anesthesiology and Intensive Care.
“These drugs are particularly needed when operating on a patient’s chest or abdomen. They are also used to protect the vocal cords from injury when a tube is placed in the airway to allow artificial ventilation,” says Blobner who is the chair of the POPULAR steering committee, a multinational group of researchers from TUM School of Medicine, Karolinska Institutet, University Hospital of Bonn, Amsterdam University Medical Center, Université de Lorraine Nancy, and the Faculty of Medicine University of Liverpool. The prospective observational POPULAR study collected data from 22,803 patients of 211 hospitals in 28 European countries.
Results confirm risk for patients
The first results from this study are now being published in “The Lancet Respiratory Medicine”. They confirm what earlier studies based on pre-existing data had hinted at: The use of neuromuscular blockers during general anesthesia is associated with a significantly increased risk of several respiratory complications after surgery.
The most common complications involving the respiratory system were a reduced capacity of the lung transiently to absorb oxygen (5.2%), and infections of the lung and respiratory tract (2.5%). Roughly three quarters of all patients (17150 people) were treated with neuromuscular blocking agents. They were shown to have a significantly higher risk (+4.4%) of developing any type of respiratory complication.
Neither monitoring nor drugs lower the risk
The study did not look into how the use of muscle relaxants might cause the negative effects. Earlier studies have shown that even small amounts of muscle relaxants remaining in the bodies of patients could be responsible for some of the complications. The data from POPULAR however show that established techniques used to avoid residual neuromuscular block do not lower the patients’ risk of pulmonary complications.
Neither drugs reversing the effects of the muscle relaxants nor monitoring of neuromuscular function during anesthesia to make sure that the muscle function is completely recovered did change the respiratory outcome. The researchers point out that this does not mean that these measures are unable to reduce residual paralysis but they must be used correctly. There may be flaws in the way these measures are implemented as well as other unknown causes for the complications.
Blocking agents remain important and helpful
“It's important to note that neuromuscular blocking agents have made surgery considerably safer and more effective since their introduction several decades ago,” says Professor Blobner. „We have constantly refined both the drugs and the techniques used. Many operations would not be possible without them. Still, the results from POPULAR raise important questions“.
Blobner and co-authors are planning to implement more targeted studies to identify the underlying mechanisms behind their findings. “Based on our results, we believe that patients undergoing minor surgical procedures that do not necessarily require neuromuscular blocking drugs might benefit from avoiding them. Using devices like laryngeal masks for anesthesia instead of tracheal tubes that go past the vocal cords could prove helpful as well,” says Blobner.
TUM's Clinic for Anesthesiology and Intensive Care: http://www.anaesth.med.tum.de/
POPULAR on the European Society of Anaesthesiology's Clinical Trial Network Website: http://www.esahq.org/research/clinical-trial-network/published-trials/popular
Prof. Dr. Manfred Blobner
Technical University of Munich
Clinic for Anesthesiology and Intensive Care Medicine
Kirmeier E, Eriksson LI, Lewald H, Jonsson Fagerlund M, Hoeft A, Hollmann M, Meistelman C, Hunter JM, Ulm K, Blobner M: Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR): a multicentre, prospective observational study. www.thelancet.com/respiratory Published online September 14, 2018 http://dx.doi.org/10.1016/S2213-2600(18)30294-7
Dr. Ulrich Marsch | Technische Universität München
Inselspital: Fewer CT scans needed after cerebral bleeding
20.03.2019 | Universitätsspital Bern
Building blocks for new medications: the University of Graz is seeking a technology partner
19.03.2019 | Karl-Franzens-Universität Graz
DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.
The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
22.03.2019 | Life Sciences
22.03.2019 | Life Sciences
22.03.2019 | Information Technology