An evaluation of the Integrated Pulmonary Index (IPI) for the detection of respiratory events in propofol sedated patients undergoing upper gastrointestinal endoscopy

Abstract

Background: Monitoring of patients respiratory and ventilatory status during moderate-to-deep sedation in upper gastrointestinal (GI) endoscopic procedures may enable early recognition of altered respiratory patterns with potential danger for vital functions. The current standards of care for monitoring the ventilatory status during sedation are pulse oximetry and visual inspection of the breathing pattern. EtCO2 monitoring is not routinely used. The Integrated Pulmonary Index (IPI) monitor is developed to detect specific patient’s respiratory depression and changes status during sedation, by measuring the EtCO2, respiratory rate, SpO2 and pulse rate, displayed on a monitor. This monitor might provide an indication of the patient’s overall ventilator status. The aim of this study was to explore the validity of the IPI index during PSA procedures and its application during upper GI endoscopy treatments, compared with our traditional current standards of monitoring care. Methods: Twenty patients, scheduled for upper GI endoscopy procedures gave their informed consent. All patients were moderately to deeply sedate by trained sedation practitioners. Aside from standard monitoring, additionally the IPI was continuously measured, on a capnostream monitor. All data were analyzed and compared with the clinical status of the patient. Results: All patients were moderate-to-deep sedated for upper GI endoscopy procedures. The mean age of the patients was 56 years. In 15/100 measure points, the IPI values (lower than 7) were not in agreement with the actual clinical state of the patient. The most common discrepancies, 9/100, were associated with an overshoot of the EtCO2 value, due to leakage of CO2, insufflated through the endoscope. Conclusion: The IPI value as an early warning monitor of the ventilation in moderate-to-deep sedation procedures remains unclear and deserves further study. Its use in upper endoscopic gastrointestinal procedures where CO2 insufflation is used by the endoscopist cannot be recommended.