The predictive value of gastric reactance for postoperative morbidity and mortality in cardiac surgery patients

Abstract

No useful method to directly monitor the level of end organ tissue injury is currently available clinically. Gastric reactance has been proposed to measure changes in a tissue structure caused by ischemia. The purpose of this study was to assess whether gastric reactance is a reliable, clinically relevant predictor of complications and a potentially useful tool to assess hypoperfusion in cardiovascular surgery patients. The value of gastric reactance measurements, standard hemodynamic and regional perfusion variables, and scores to predict postoperative complications were compared in 55 higher risk cardiovascular surgery patients with cardiopulmonary bypass. Low frequency gastric reactance, X(L), had a significant predictive value of postoperative persistent shock requiring more than 48 h of vasopressors and associated complications, before, during and after surgery (p < 0.05). Results suggest that reactance is an earlier predictor of patients at risk than all other variables tested. Patients with a high reactance (X(L) > 26) before surgery had a significantly higher incidence of complications, higher mortality and more days in the ICU than patients with a low reactance (X(L) < 13). X(L) was found to be a reliable and clinically relevant measurement. These results justify further clinical research to explore how this information may be used to improve patient management.

Gastric Tissue Damage Analysis Generated by Ischemia: Bioimpedance, Confocal Endomicroscopy, and Light Microscopy

“…We proposed that bioimpedance and particularly gastric reactance is an early indicator of ischemia and we developed some studies that confirm the prognostic and diagnostic value of these measurements [20, 21]. However, before we may advocate the clinical use of this technology we need to first answer the following questions: (1) Can we quantify oedema and tissue damage from impedance parameters?, (2) Can we use this information to improve patient management and treatment?…”

Gastrointestinal ischemia monitoring through impedance spectroscopy as a tool for the management of the critically ill

“…Our research group reported a relationship between bioimpedance changes with tissular damage level generated by ischemia by means of confocal endomicroscopy and light microscopy 21 ; also two animal models of shock were made, one to monitor ischemic injury of the intestinal mucosa in a hemorrhagic shock model in rabbits, 22 other to show that combined splanchnic tissue indicators have the potential of been used as complementary tools for guiding a treatment in septic shock. 23 Finally, we developed some human studies to evaluate the clinical significance of the impedance measurements: in healthy volunteers, 24 in elective cardiovascular surgery patients, [25][26][27] and the last one in general critically ill patients. 28 This document attempts to summarize our work to date, showing the importance of gastric ischemia monitoring and main animal and human results.…”

“…Normal is defined as patients with a mean X L value below the threshold of 13 (green), very abnormal as above the threshold of 26 (red). The number presented at the top of each branch is the number of patients, followed by the number of patients who developed complications and its percentage Table 1 Analysis of receiver operating curves of impedance parameters and scoring systems obtained before, during, and after surgery (adapted from Beltran et al 27 ). percentage.…”

“…Finally, we developed some human studies to evaluate the clinical significance of the impedance measurements: in healthy volunteers, 24 in elective cardiovascular surgery patients, 25–27 and the last one in general critically ill patients. 28 This document attempts to summarize our work to date, showing the importance of gastric ischemia monitoring and main animal and human results.…”

Incidence of Gastric Mucosal Injury as Measured by Reactance in Critically Ill Patients

“…18 It was reported that hypoperfusion and ischemia cause changes in the impedance measurements of the gastric wall in cardiovascular surgery patients. 19 The value of these measurements as a prognostic index of postoperative outcome in cardiovascular surgery patients was validated by Beltran et al 20…”