Influence of Rapid Fluid Loading on Airway Structure and Function in Healthy Humans
Received 5 June 2009; received in revised form 12 August 2009; accepted 17 August 2009. published online 23 October 2009.
Abstract
Background
The present study examined the influence of rapid intravenous fluid loading (RFL) on airway structure and pulmonary vascular volumes using computed tomography imaging and the subsequent impact on pulmonary function in healthy adults (n = 16).
Methods and Results
Total lung capacity (ΔTLC = −6%), forced vital capacity (ΔFVC = −14%), and peak expiratory flow (ΔPEF = −19%) decreased, and residual volume (ΔRV = +38%) increased post-RFL (P < .05). Airway luminal cross-sectional area (CSA) decreased at the trachea, and at airway generation 3 (P < .05), wall thickness changed minimally with a tendency for increasing in generation five (P = .13). Baseline pulmonary function was positively associated with airway luminal CSA; however, this relationship deteriorated after RFL. Lung tissue volume and pulmonary vascular volumes increased 28% (P < .001) post-RFL, but did not fully account for the decline in TLC.
Conclusions
These data suggest that RFL results in obstructive/restrictive PF changes that are most likely related to structural changes in smaller airways or changes in extrapulmonary vascular beds.
1Department of Physiology and Biomedical Engineering and Department of Internal Medicine, Mayo Clinic, Rochester, MN
2Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
3Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA
Reprint requests: Dr. Bruce D. Johnson, Mayo Clinic College of Medicine, Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905. Tel: (507) 284-4441.
This study was supported by the National Institute of Health Grant HL71478 and Center for Translational Science Activities Grant Number 1 UL1 RR024150.
ABSTRACT