Reflectance spectrophotometry for the assessment of gastroduodenal mucosal perfusion

1987 ◽  
Vol 252 (6) ◽  
pp. G797-G804 ◽  
Author(s):  
F. W. Leung ◽  
T. Morishita ◽  
E. H. Livingston ◽  
T. Reedy ◽  
P. H. Guth
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Regional Differences ◽  
Hemoglobin Concentration ◽  
Mucosal Blood Flow ◽  
Celiac Artery ◽  
Artery Occlusion ◽  
Reflectance Spectrophotometry ◽  
Vein Occlusion ◽  
Mucosal Perfusion

Reflectance spectrophotometry in assessing gastroduodenal mucosal perfusion was evaluated. Ischemia without congestion, e.g., during hemorrhagic hypotension or celiac artery occlusion, was associated with a reduction in the indexes of mucosal hemoglobin concentration and of oxygen saturation. Ischemia with congestion, e.g., during portal vein occlusion, or in absolute ethanol or suction-induced mucosal lesions, was associated with an increase in the index of mucosal hemoglobin concentration but a reduction in the index of oxygen saturation. An increase in the index of mucosal hemoglobin concentration associated with a normal index of oxygen saturation was found in the postischemic hyperemia after release of celiac artery occlusion and during the sustained increase in corpus mucosal blood flow induced by vagus nerve stimulation. Thus reflectance spectrophotometric measurements reflected ischemia, without or with congestion, and hyperemia. Additionally, although regional differences in reflectance spectrophotometric measurements were demonstrated in the duodenal, antral, and corpus mucosa, such differences bore no consistent relationship to regional differences in blood flow demonstrated in previous studies.

Octreotide decreases canine gastric mucosal blood flow: A controlled assessment by endoscopic reflectance spectrophotometry

1994 ◽  
Vol 40 (1) ◽  
pp. 56-61 ◽  
Author(s):  
Paul R. Tarnasky ◽  
Thomas O.G. Kovacs ◽  
Felix W. Leung ◽  
Ken Hirabayashi ◽  
Dennis M. Jensen
Keyword(s):  
Blood Flow ◽  
Mucosal Blood Flow ◽  
Gastric Mucosal Blood Flow ◽  
Reflectance Spectrophotometry

Limitations of laser-Doppler velocimetry and reflectance spectrophotometry in estimating gastric mucosal blood flow

1992 ◽  
Vol 263 (5) ◽  
pp. G810-G815 ◽  
Author(s):  
M. Casadevall ◽  
J. Panes ◽  
J. M. Pique ◽  
J. Bosch ◽  
J. Teres ◽  
...  
Keyword(s):  
Blood Flow ◽  
Gastric Mucosa ◽  
Reference Method ◽  
Mucosal Blood Flow ◽  
Gastric Mucosal Blood Flow ◽  
Hydrogen Gas ◽  
Laser Doppler ◽  
Reflectance Spectrophotometry ◽  
Doppler Flowmetry ◽  
Normovolemic Anemia

This study investigated the accuracy of laser-Doppler flowmetry (LDV) and reflectance spectrophotometry (RS) measurements as an index of blood flow in the gastric mucosa of the rat, in experimental conditions such as pharmacologically induced vasoconstriction, hypoxia, hyperoxia, and acute normovolemic anemia. Hydrogen gas clearance was used as a reference method. After vasopressin infusion, LDV signal and indexes of hemoglobin (IHb) and oxygen (ISO2) content in the gastric mucosa estimated by RS significantly decreased in parallel with the reduction of gastric mucosal blood flow (GMBF). Neither hypoxia (5% O2 administration) nor hyperoxia (100% O2) affected GMBF or LDV signal. However, both IHb and ISO2 significantly decreased or increased after hypoxia or hyperoxia, respectively. Acute normovolemic anemia induced a significant increase in GMBF, while LDV signal and ISO2 remained unchanged. IHb significantly decreased in linear relationship with the decrements in the hematocrit. It is concluded that 1) in pharmacologically induced GMBF changes, LDV and RS correlate with GMBF; 2) when changes in hemoglobin saturation are induced, LDV but not RS reflects GMBF; and 3) in acute normovolemic anemia, neither LDV nor RS reflects changes in GMBF.

Relationship of blood flow to antral lesion incidence in rat gastric mucosa after hemorrhage and retransfusion

1994 ◽  
Vol 266 (6) ◽  
pp. G1011-G1016
Author(s):  
A. Hachiya ◽  
M. Bessho
Keyword(s):  
Blood Flow ◽  
Hemoglobin Concentration ◽  
Mucosal Blood Flow ◽  
Causative Role ◽  
Antral Mucosa ◽  
Histological Lesion ◽  
Rat Gastric Mucosa ◽  
Gastric Mucosal Hemodynamics ◽  
Relationship Of ◽  
The Relationship

The relationship of gastric mucosal hemodynamics, energy metabolism, and acid to antral histological lesion incidence following hemorrhage and retransfusion was investigated in rats. Decrease of mucosal blood flow and of the index of mucosal oxygen saturation (ISO2) during hemorrhage were slightly greater in the corpus than in the antrum. ATP content and redox ratio in the corpus were decreased by shock; however, these hardly changed in the antrum. The index of tissue hemoglobin concentration (IHb) recovered to above the prehemorrhage value only in the antrum after retransfusion. Histological lesion incidence in the antral mucosa was more markedly increased by acid instillation and/or retransfusion than in the corpus. From these results, it was concluded that the decrease of blood flow is related as an underlying factor to induction of ischemic damage in the antral mucosa and that intraluminal acid and/or postischemic hyperemia play a causative role in the development of histologic lesions in the antral mucosa during shock and retransfusion in the rat stomach.

Clinical Application of Tissue Reflectance Spectrophotometry to Periodontal Disease

1988 ◽  
Vol 2 (2) ◽  
pp. 389-394 ◽  
Author(s):  
S. Shizukuishi ◽  
T. Hanioka ◽  
A. Tsunemitsu
Keyword(s):  
Periodontal Disease ◽  
Oxygen Saturation ◽  
Hemoglobin Concentration ◽  
Gingival Tissue ◽  
Reflectance Spectrophotometry ◽  
Oxygen Utilization ◽  
Oxygen Saturation Level ◽  
In Vivo Experiments

Rapid, accurate, and non-invasive measurements of hemodynamics and oxygen utilization in gingiva are clinically important in evaluation of the severity of the inflammatory response in periodontal disease. In the present study, tissue reflectance spectrophotometry was used to examine gingiva in vivo to estimate hemoglobin concentration (Hb index) and the oxygen saturation level of hemoglobin in gingiva (HbSO2 index). Reflectance spectrophotometry was also used to examine these parameters in experimental periodontitis in dogs, and in patients with periodontal disease. Both in vitro and in vivo experiments confirmed that the Hb index was positively correlated with hemoglobin concentration in gingival tissue. The relationship between the HbSO2 index and PO2 in gingiva was a sigmoid curve resembling the hemoglobin-oxygen dissociation curve. In rapidly advancing periodontitis resulting from ligature placement in dogs, the Hb index was significantly enhanced, but the HbSO2 index was reduced. This reduction corresponded to increases in gingival inflammation during the experiments. Furthermore, in humans, the Hb index was significantly higher in inflamed gingiva than in clinically healthy gingiva. A lower HbSO2 index was also found in inflamed gingiva. These findings are consistent with congested blood vessels, impaired venous return, and localized hypoxia in inflamed gingival tissue. Tissue reflectance spectrophotometry is clinically useful in estimating blood volume and oxygen saturation in diseased gingiva.

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