Table 7.

Investigations of voice changes post fluid removal in vivo

#	Pt	Hydration Inducement	Hydration Measures	Hydration Status	Vocal Function measures	Main Results	Conclusions
Fisher et al. (2001) (48)	6M 2 F 40–85 yr 7pts end stage renal disease 1M healthy	Method Dialysis treatment including sodium modeling Able to drink ≤60z liquids + saline IV Fluid reversal fluid consumption according to pt customary habits Timing Fluid consumption overnight	Method Weight Fluid removed & delivered Blood pressure Temp. Heart Rate Timing Weight pre-dialysis Vitals every 15min	Pre presumed to be hypervolemic Post Not measured	Measures PTP 30 PPE Singing ‘Happy Birthday’ 11point scale PPVQ rating 11 point scale Timing Pre ✓ Post ✓	↓ body fluid correlated with ↑PTP & ↑PPE Fluid loss = 16–64% variance in PTP Phonatory changes were not considered to interfere with activity, were improved 6hrs post, and not present in all cases. 2 pts showed no reliable treatment response	Voice deterioration can result from rapid & severe hydration challenges Removal of extracellular water in a hypervolemic state to induce a normovolemic state can result in voice changes Phonation can occur despite large-volume & fast fluid removal from the body
Ori et al. (2006) (57)	11 M 5 F 35–78yr Chronic Hemodialysis 1.5–15yr	Method Dialysis session Timing 4 hours	Method Dry weight Weight Blood pressure Timing Before & after dialysis	Pre hypervolemic Post 3/8 pt = drywgt 2/8 pt > drywgt 3/8 pt < drywgt	Measures Lx imaging Measurement of VFs area, length, width PPVQ hoarseness mild or sig. Timing Pre ✓ Post ✓	Post dialysis VF thickness ↓ in 13/16pts, but ↑ in 3/16pts ↓ weight & blood pressure 62% pt perceived post dialysis hoarseness No relationship between perceived hoarseness & VF thickness changes	Pts may experience transient hoarseness when undergoing chronic hemodialysis ↓ VF thickness is observed during dialysis, probably as a result of hydration removal