Critical illness polyneuropathy (CIP) is a condition which occurs in intensive care medicine. Nerves stop functioning properly in patients who are critically ill, and muscle weakness and paralysis develop, making it difficult to move the limbs or breathe. This could mean that patients who were going to be removed from a ventilator have to remain on it and they might also have to stay longer in the hospital. Critical illness polyneuropathy is likely to occur in adults who are suffering from sepsis, where infection overwhelms the body, and multiple organ dysfunction, where a number of organs stop working properly. It is possible to recover from the condition but recovery appears to be slow.
Around 70 percent of patients with sepsis develop critical illness polyneuropathy. It is most likely to occur in male patients in intensive care who have inflammation throughout the body and breathing difficulties, and who are over 50 years of age. Inflammation of the entire body is known as systemic inflammatory response syndrome (SIRS) and this can be associated with infections, burns, severe injuries and blood loss. Signs of CIP include being unable to breathe without assistance, reduced limb movements and sometimes paralysis of the facial nerve.
Critical illness polyneuropathy is often associated with a similar condition known as critical illness myopathy (CIM), where muscles stop functioning properly. Both conditions cause muscle weakness and it can be difficult to distinguish between the two, particularly as both can occur together. Electrophysiologic testing of nerves shows abnormal nerve function in both CIP and CIM. A muscle biopsy, where a sample of muscle is removed and analyzed to look for abnormalities, can be used to diagnose CIM. In practice, the treatment for both critical illness polyneuropathy and CIM is the same, so it is not necessary to differentiate between them.
Research is ongoing into an effective treatment for critical illness polyneuropathy, so it is important to try and prevent the condition from developing in the first place. Prevention involves treating sepsis and multiple organ dysfunction as soon as possible before CIP develops. It is thought that the use of certain drugs, such as high doses of steroids, might increase the risk of CIP, so these should be avoided if possible. Those patients who survive their illness and leave intensive care may recover from CIP, although progress is slow and some may still experience some abnormalities over a year later. Patients with more severe cases of sepsis tend to have a poorer outlook.
