The symptom of fatigue can be associated with much pathology, but invariably for many patients it is often a symptom of poor lifestyle – as the Mars Bar advert says “Work/Rest/Play” i.e there is usually an imbalance with Overwork/ Poor Quality sleep / Inappropriate Exercise activity, and I would also add Inappropriate Ingesting (e.g. poor diet).
Nonetheless, when clinical history or family history raises concern it may be prudent to exclude organic pathology.
Typically, clinical history and exam should help rule out Cardio-respiratory disorders or Neuro-muscular disorders as a cause of fatigue and in particular exertional fatigue.
If a diagnosis is not clear basic pathology testing with E/LFT, FBC, TSH, and Iron Studies would be suitable for first-line screening. What is of relevance here it whether the patient is anaemic or not. Anaemia in itself is also a “symptom” – there is usually a cause, and although GI bleeding may be one cause, most anaemias are due to other disease processes.
Moreover, the non anaemic patient may still have fatigue related to suboptimal iron status. New Australian guidelines have suggested Iron sufficiency usually requires a ferritin of 30ug/L or more. Often patients (male or female) will be iron deplete with ferritins between 10-30, yet their Hb will be within the reference range – although a quick comparison with Hb levels from previous years may reveal a downtrend in Hb levels.
Iron is not only required for Haemoglobin function, but is also relevant in muscle myoglobin and intra-cellular enzyme function.
The FERRIM study was to determine the efficacy of intravenous iron compared with placebo in decreasing fatigue 6 weeks after treatment initiation in non-anemic patients with iron deficiency (serum ferritin ≤50 ng/ml). Fatigue was assessed using the Brief Fatigue Inventory (BFI; severity of fatigue) and the Short Performance Inventory (SPI; improvement in fatigue) questionnaires. Patients were followed-up for 12 weeks. Patients in the intravenous iron group reported improvement in fatigue (65% and 63% of patients after 6 and 12 weeks, respectively) significantly more often than in the placebo group (40% and 34% of patients after 6 and 12 weeks, p=0.02 and 0.006, respectively) as evaluated by the SPI.
Unfortunately, there is a subgroup of patients who continue to suffer long-term Chronic Fatigue not due to any obvious aetiology. One of the hallmarks of these patients is systemic exertion intolerance.
The disease known as chronic fatigue syndrome (CFS) has long defied classification, because the symptoms vary greatly in the millions of people who are affected by it. In February 2015 a panel commissioned by the US Department of Health and Human Services (HHS) produced an influential report on how the disease should be diagnosed. The guidelines come with a new moniker: systemic exertion intolerance disease (SEID).
The treatment of these various diseases related to fatigue will sometimes be fairly straight forward such as the provision of iron infusion for those patients with sub-optimal iron status.
Yet other times, conditions such as SEID may require a more eclectic approach to therapy.
Dr Davidson offers IV infusion therapy at NLDH.