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
New 3D cultured cells mimic the progress of NASH
02.04.2020 | Tokyo University of Agriculture and Technology
Geneticists are bringing personal medicine closer to recently admixed individuals
02.04.2020 | Estonian Research Council
Electrolytes play a key role in many areas: They are crucial for the storage of energy in our body as well as in batteries. In order to release energy, ions - charged atoms - must move in a liquid such as water. Until now the precise mechanism by which they move through the atoms and molecules of the electrolyte has, however, remained largely unknown. Scientists at the Max Planck Institute for Polymer Research have now shown that the electrical resistance of an electrolyte, which is determined by the motion of ions, can be traced back to microscopic vibrations of these dissolved ions.
In chemistry, common table salt is also known as sodium chloride. If this salt is dissolved in water, sodium and chloride atoms dissolve as positively or...
Drops of water falling on or sliding over surfaces may leave behind traces of electrical charge, causing the drops to charge themselves. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now begun a detailed investigation into this phenomenon that accompanies us in every-day life. They developed a method to quantify the charge generation and additionally created a theoretical model to aid understanding. According to the scientists, the observed effect could be a source of generated power and an important building block for understanding frictional electricity.
Water drops sliding over non-conducting surfaces can be found everywhere in our lives: From the dripping of a coffee machine, to a rinse in the shower, to an...
90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous
An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...
The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.
One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...
An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.
A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...
06.04.2020 | Event News
02.04.2020 | Event News
26.03.2020 | Event News
06.04.2020 | Life Sciences
06.04.2020 | Power and Electrical Engineering
06.04.2020 | Social Sciences