Health Rising had a recent post “IV Saline Solution For Chronic Fatigue Syndrome (ME/CFS)” with links to The Nitty Gritty on IV Saline and POTS / Speed and frequency – Does it Matter? and Dr. David Bell “Intravenous Fluid as a Treatment for ME/CFS”.
A reader had to give a presentation and had a flare. An IV solution enabled the reader to proceed with an excellent presentation. “I was able to get a saline IV which helped a tremendous amount. I also took some aspirin. I still had aphasia on stage but it made it 10x more dramatic and well received. The talk was a smashing success.”
My read of saline solution impact was because it reduced coagulation, decreased blood viscosity (allow it to flow faster), in addition to increasing blood volume. Hypercoagulation (thick blood) is a very common problem with CFS, as well as low blood volume.
- “The hypertonic saline solution therapy could significantly improve blood viscosity and reduced viscosity”
- ““Even as late as World War II and the Vietnam Way, it was thought that adding isotonic fluids to replace blood lost on the battlefield would be good because it lowered blood viscosity, making it easier for the heart to pump.”[UCSD]
- “At 10% blood volume replacement with hypertonic saline, reaction and coagulation times were significantly increased… We conclude that 7.5% hypertonic saline solution has anticoagulant effects if it replaces 7.5% or more of blood volume.”
- Human blood volume is 4.7 liters, so 0.35 liters or 1 1/2 cup would have an impact
- “Most institutions recommend the use of heparin to prevent occlusion [in catheters], however there is debate regarding the need for heparin and evidence to suggest 0.9% sodium chloride (normal saline) may be as effective.” 
- “Normal saline influences coagulation and endothelial function after traumatic brain injury and hemorrhagic shock in pigs.”Normal Saline resuscitation was associated with an early activation of coagulation, natural anticoagulation, and endothelial systems,”