Evaluation of Respiratory Function in Fibromyalgia
Condition: Fibromyalgia; Respiratory Alkalosis and Metabolic Acidosis; Chronic Hyperventilation
MeSH terms: Fibromyalgia; Myofascial Pain Syndromes; Hyperventilation; Alkalosis, Respiratory; Acidosis; Alkalosis
Study type: Observational

Summary: 
      This study will evaluate respiratory function in people with fibromyalgia and whether or not
      breathing patterns in this patient group can be explained by stress, emotional or
      biomechanical variables. In addition, examine the relationship between physical ability and
      lactate values.
    

Detailed description: 
      Fibromyalgia is characterized by persistent widespread pain and affects approximately 1-3% of
      the general population. Fibromyalgia is a multifactorial syndrome and much research has been
      done and several interesting facts discovered. Still, the etiology is unknown. The autonomic
      nervous system may be the cause of several symptoms of this condition and a pattern of
      abnormal autonomous functions has been described . Besides the autonomous nerve system the
      respiratory system has also potential to impact various body organs mainly by altered blood
      gas chemistry. Deviant respiratory function in local pain condition as in cervical and lumbar
      spine has been reported. Respiratory function in generalized pain as in people with
      fibromyalgia has not been given much consideration.

      This project is an observational cross sectional study with the purpose to examine
      respiratory function in people with fibromyalgia and compare with age-matched controls.

      Respiratory function will be examined by spirometry and blood gases. Both static (vital
      capacity, tidal volume) and dynamic lung volumes (forced vital capacity, forced expiratory
      volume in 1 second) and the ratio of forced expiratory volume in 1 second and forced vital
      capacity will be used. Spirometry will be performed in seated position. Respiratory rate will
      be examined in a sitting position using intensive care equipment with electrodes placed under
      each clavicle and over the lower ribs on the left side. After five minutes of relaxing,
      breathing frequency is observed during one minute. A value is noted every ten second and a
      mean value is calculated. Subjects are not aware of when the observation begin. An arterial
      blood sample will be taken to determine carbon dioxide, oxygen, saturation, bicarbonate, pH
      and base excess levels. Other blood samples that will be taken is magnesium in venous blood
      and lactate in capillary blood. Arterial and venous blood samples will be taken in supine
      position while capillary samples will be done in seated position. Lactate will be sampled
      before and directly after a six minutes walking test.

      Chest mobility, postural balance, spinal mobility, pain sensitivity test and body mass index
      will be measured as physical or biomechanical variables. By using a tape measure chest
      mobility will be measured in a standing position at the xiphoid process and axillary level.
      Spinal mobility will be measured in a seated position between C7-T5 measuring the difference
      between upright position and full flexion of the spine. By using an analyzing software
      program called Cervico thoracic ratio 5.0, postural balance can be calculated based on the
      same method of measuring spinal mobility described above. Pain sensitivity test will be
      performed over paraspinal muscles between the level of C7-T7 with a total of 14 locations by
      using a pressure algometer with the subject lying prone. Measurement of the subject's weight
      and height will be recorded and the body mass index (BMI) will be calculated.

      Heart rate variability and self administered questionnaires (Hospital and anxiety depression
      scale, Pain catastrophizing scale, Perceived stress scale, Montgomery-Asberg Depression
      Rating Scale) will be used to assess stress or emotional variables. The Rand 36-item will be
      used as a quality-of-life measurement. Heart rate variability will be measured during five
      minutes by a portable ECG device in a sitting position with electrodes placed under each
      clavicle and over the lower ribs on the left side. Questionnaires are encouraged to be filled
      in before the visit.

      For physical function a standardized six minutes walking test and a chair stand test will
      take place for measuring endurance and strength.

      All measurement will be executed at the same visit. Data about smoking habits, pain duration,
      analgetic drug use will be registered.
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        Patients with diagnosed fibromyalgia and healthy subjects included as controls.
      
Keywords: Fibromyalgia; Respiratory function