A Newly Developed Sublingual Tonometric Method for the Evaluation of Tissue Perfusion and Its ValidationIn Vitroand in Healthy PersonsIn Vivoand the Results of the Measurements in COPD Patients

Introduction. Since its first publication in the medical literature, an extremely large number of references have demonstrated that the tonometric measurement of tissue perfusion is a reliable indicator of the actual condition of critically ill patients. Later a new method was developed by the introduction of sublingual tonometry for the determination of tissue perfusion. In comparison with gastric tonometry, the new method was simpler and could even be used in awake patients. Unfortunately, at present, because of severe failures of manufacturing, the device is withdrawn from commerce.Materials and Methods. In this study, we present a new method using a newly developed tool for the PslCO2measurement in sublingual tonometry as well as the data for its validationin vitroandin vivoand the results of 25 volunteers and 54 COPD patients belonging to different GOLD groups at their hospitalization due to the acute exacerbation of the disease but already in a stable condition at the time of the examination.Results and Conclusion. The results of the performed examinations showed that the method is suitable for monitoring the actual condition of the patients by mucosal perfusion tonometry in the sublingual region.

Moderate-dose Vasopressin Therapy May Impair Gastric Mucosal Perfusion in Severe Sepsis

Background The effects of moderate-dose vasopressin on gastric mucosal perfusion and its relation to global and hepatosplanchnic hemodynamic and oxygen transport variables were investigated in patients with severe sepsis. Methods Vasopressin was administered at a dose of 0.04 IU · kg⁻¹ · h⁻¹ over 4 h in 12 patients with severe sepsis who were receiving norepinephrine. During the study period, the norepinephrine infusion rate was reduced to keep mean arterial blood pressure constant. Hepatosplanchnic blood flow, oxygen delivery, and oxygen consumption (via hepatic venous catheterization using the Fick principle and continuous indocyanine green infusion technique), global hemodynamics (transpulmonary thermodilution method), and the difference between the gastric mucosal and arterial carbon dioxide tension (Pco₂-gap) were measured at baseline and 4 h after the start of the vasopressin infusion. Results The administration of 0.04 IU · kg⁻¹ · h⁻¹ vasopressin over 4 h was associated with minimal changes in global hemodynamics. Heart rate decreased slightly from 99 [81-115] (median [interquartile range]) to 96 [74-109] beats/min (P = 0.016) and cardiac index from 3.7 [2.8-4.7] to 3.5 [2.7-3.6] L · min⁻¹ · m⁻² (P = 0.003). Global oxygen delivery index decreased significantly from 461 [375-637] to 419 [352-551] ml · min⁻¹ · m⁻² (P = 0.002), whereas hepatosplanchnic blood flow and oxygen uptake remained unchanged. Gastric mucosal Pco₂-gap increased significantly from 13.3 [8.0-16.7] to 17.1 [10.3-28.7] mmHg (P = 0.002), suggesting that blood flow may have been redistributed away from the gut mucosa. Conclusions Vasopressin at a dosage of 0.04 IU · kg⁻¹ · h⁻¹ may impair gastric mucosal perfusion with minimal global hemodynamic effects.