Muscular atrophy common in intensive care

Lars Larsson, Professor of Neurophysiology specialising in Muscular Physiology at the Department of Physiology and Pharmacology researches muscle cells and how ageing and disease impair muscle function. He is particularly interested in a type of muscle paralysis that affects some patients in intensive care and hopes to understand the underlying mechanisms, improve diagnostics and develop specific treatment methods.

Professor Lars Larsson. Photo: Ulf Sirborn

Many intensive care patients on a respirator develop serious muscular atrophy or paralysis of the muscles of the torso and limbs. The condition causes considerable suffering, increases the risk of complication and contributes greatly to the cost of healthcare. Lars Larsson, who researches muscle cells, described the first patient in Sweden with this specific muscle disease 20 years ago, and since then has focused his work on the causes of this muscular atrophy and on improving diagnostics and developing methods of treatment.

“An estimated 30 to 60 per cent of patients in intensive care and on a respirator are affected by this muscle disease,” he says, “but unfortunately many still are not diagnosed correctly.”

Professor Larsson’s research has highlighted the causes of the atrophy, which is the result of a lack of the motor protein myosin. One of the most important triggers is the total absence of muscular load, activity and other mechanical influence. This condition, which is unique to the intensive care situation, activates processes that cause a critical drop in the muscle cells’ contractile protein.

“Mechanical stimulation of the muscles, by which I mean active physiotherapy, can therefore offset this atrophy,” he explains.

Professor Larsson’s research group is now working on evaluating the protective effect on the musculature of different substances and on passing potential therapies on to clinical trials and, hopefully, to routine care.

Text: Anders Nilsson, first published in "From Cell to Society" 2015. Translation: Neil Betteridge.