Comparison of initial distribution volume of glucose and plasma volume in thoracic fluid-accumulated patients

Objective; We have reported that initial distribution volume of glucose ind icates the central extracellular fluid volume in the presence of fluid gain or loss. The purpose of this study was to describe changes in initial dist ribution volume of glucose, plasma volume determined by the indocyanine gre en dilution method (PV-ICG), and thoracic fluid content by thoracic electri cal bioimpedance in patients with or without apparent thoracic fluid accumu lation in the absence of pleural effusion. We also sought to test whether i nitial distribution volume of glucose rather than PV-ICG mirrors thoracic f luid content. Design. Prospective, clinical study. Setting. General intensive care unit. Patients. Eleven consecutive patients with apparent thoracic fluid accumula tion as judged by thoracic fluid content >0.05/ohm and underlying pathology and 20 consecutive acute myocardial infarction patients within 24 hrs afte r its onset were selected for study. None of the acute myocardial infarctio n patients had thoracic fluid content >0.05/ohm. Interventions: Five grams of glucose and 25 mg of indocyanine green were ad ministered simultaneously to calculate initial distribution volume of gluco se and PV-ICG daily for the fluid-accumulated patients, and the same dosage s were administered to the acute myocardial infarction patients immediately after their admission to the intensive care unit after percutaneous corona ry angioplasty. Only the data on the day of the maximal and minimal thoraci c fluid content in the fluid-accumulated patients were used for the study. The relationship between these two fluid volumes and thoracic fluid content was evaluated in the two patient groups. Measurements and Main Results. Initial distribution volume of glucose and t horacic fluid content rather than PV-ICG and thoracic. fluid content moved together in the same direction in each fluid-accumulated patient. Neither p ulmonary artery occlusion pressure, central venous pressure, nor PV-ICG pro duced a better correlation with cardiac index when compared with initial di stribution volume of glucose in patients with or without thoracic fluid acc umulation. Conclusions. We suggest that initial distribution volume of glucose rather than PV-ICG is a better indicator of the intrathoracic blood volume status, even although intravenously administered glucose cannot stay in the intrav ascular compartment.