Assessment of photoplethysmographic signals for the determination of splanchnic oxygen saturation in humans

Abstract

SummaryThe need for a clinically applicable method of detecting splanchnic hypoxia has led to experimental animal studies which indicated the usefulness of intestinal pulse oximetry. Pulse oximetry relies on detection of photoplethysmographic signals. Before developing a pulse oximeter for the measurement of organ oxygen saturation peri-operatively, we designed a system based on a re¯ectance photoplethysmographic probe to investigate photoplethysmographic signals from human viscera (bowel, liver, and kidney). Recordings were obtained simultaneously from the abdominal viscera and the ®nger using identical probes. The probe was held sequentially for up to 2 min on the surface of viscera of 12 patients during routine laparotomy. Measurable splanchnic photoplethysmographic signals were recorded for the ®rst time in humans. There were no statistically signi®cant differences between photoplethysmographic amplitudes from viscera and those from the ®nger. Our results indicate the feasibility of pulse oximetry for the measurement of visceral oxygenation in humans.

Investigation of photoplethysmographic signals and blood oxygen saturation values obtained from human splanchnic organs using a fiber optic sensor

“…Currently, there is no widely accepted and readily available monitoring technique to assess splanchnic perfusion [5]. Polarographic oxygen electrodes have been used to monitor splanchnic tissue oxygenation, but predominately remain as research tools [1].…”

“…Studies in animals have found it to be a rapid, reproducible, as well as a highly sensitive and specific technique for detecting small bowel ischemia [10]. More recently an electro-optical pulse oximetry sensor has been used for the first time in humans to measure photoplethysmographic (PPG) signals from various abdominal organs [5]. However, none of these sensors are suitable for prolonged monitoring in the abdomen.…”

Pulse oximetry and photoplethysmographic waveform analysis of the esophagus and bowel

“…The esophageal pulse oximeter has also been used to investigate PPG signals in the human bowel [11]. In many critically ill patients, poor tissue oxygenation is due to disordered regional distribution of blood flow, despite high global blood flow and oxygen delivery.…”

Development of a New Splanchnic Perfusion Sensor

“…PLANCHNIC organs are particularly vulnerable to hypoperfusion [1]. If an organ or tissue is not sufficiently perfused with oxygenated blood, cell death and tissue necrosis can ensue.…”