Predicting Neck Fluid Accumulation While Supine.

Daniel Vena,Azadeh Yadollahi,Babak Taati

doi:10.1260/2040-2295.6.4.673

Abstract

When lying supine, fluid shifts rostrally from the legs and accumulates in the neck, which is a risk factor for obstructive sleep apnea. The objective of this study was to model neck fluid accumulation using one-time baseline measurements of body fluid, demographics, and anthropometrics. Using bioelectrical impedance, leg and neck fluid volumes (LFV and NFV) were measured continuously and simultaneously. Thirty non-obese adults (13 men) stood quietly for 5 minutes, and then lay supine for 90 minutes while fluid volumes were measured. Neck circumference (NC) was measured before and after the supine period. Results demonstrated that, compared to women, men experienced a greater increase in NC after lying supine. Furthermore, baseline LFV at the onset of lying supine was significantly correlated with ΔLFV (r = 0.44, p = 0.014) and ΔNC (r = 0.51, p = 0.008) after 90 minutes supine. The findings identify that sex and baseline LFV predict both the fluid leaving the legs and increase in NC during recumbency.

Highlights

Overnight neck fluid accumulation is a risk factor for upper airway pathologies and respiratory disorders [1]–[4]
Women had lower baseline neck fluid volume (NFV) and leg fluid volume (LFV) at standing and supine. Both experienced a similar change in LFV over the 90-minute supine period
In conclusion, this study demonstrates that a baseline measure LFV is predictive of the amount of fluid leaving the legs and the change in neck circumference (NC) after lying supine for 90 minutes

Summary

Introduction

Overnight neck fluid accumulation is a risk factor for upper airway pathologies and respiratory disorders [1]–[4]. The accumulation of neck fluid could cause distension of the neck veins and/or edema formation in the pharyngeal soft tissue. These changes increase pressure on the upper airway and could cause the narrowing of the upper airway [3, 5, 6], increase upper airway resistance [1,7] and collapsibility [4,8], and increase the severity of obstructive sleep apnea (OSA) [9]. It has been demonstrated that the volume of fluid leaving the legs while recumbent is correlated with increased neck circumference (NC) signaling the accumulation of fluid in the neck [2, 10, 11]

Objectives

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Results

Discussion

Conclusion