Opioid Induced Respiratory Depression

Investigators will enroll 493 patients who will undergo non-cardiac surgery, receive supplemental oxygen via face mask or nasal cannula, and will be on continuous pulse oximetry monitor in the Post Anesthesia Care Unit (PACU). Research personnel will screen and select subjects for this study. The CRA will ensure that each subject meets the enrollment criteria, and the informed consent is properly executed. Upon arrival at the PACU, each subject will be fitted with a supplemental oxygen mask or nasal cannula containing the Linshom sensor, which will be connected to Linshom Cyber G-15 monitor for data collection. A pulse oximeter will be applied to the hand (non-NIBP arm), which will be connected to a hospital monitor (SOC). The Linshom G-15 monitor will collect data every 100 milliseconds. The Linshom CPRM will automatically initiate baseline data capture. The CRA will begin recording any clinical interventions (e.g., medications and stimulation upon detection of changes in patient's condition) that are performed by the PACU staff, paying close attention to time at which those interventions occurred. Data collection will be performed throughout the subject's entire PACU stay. After data collection, the Linshom engineers will retrieve the data from all monitors and time-sync all data collected from each patient (Linshom CPRM and pulse oximetry). Manually recorded data regarding the time points at which clinical interventions were provided by the PACU staff will also be reviewed and those time points will be noted as RDEs. The Linshom CPRM system monitors the distinct metric of RDE occurrence. Throughout a given patient's stay, nurses will be provided with two distinct cues (each cue comprised of an auditory and visual component), 1 from CPRM, 1 from SoC, alerting them to a patient's respiratory state. In addition, clinical staff will have access to a summary metrics of critical parameters and RDE occurrences on the Linshom monitor (total RDE count, time since last RDE).

The goal of this study is to determine if a relationship can be detected between the administration of an opioid and quantitative respiratory depression in spontaneously breathing non-intubated patients who have undergone general anesthesia and have received perioperative opioids. The primary aim is to determine the temporal effect of opioid administration on respiratory depression as assessed by minute ventilation with a reduction of at least 20% in the percent of predicted minute ventilation. A secondary aim is to determine a dose response of opioid administration and its effect on minute ventilation. The investigators aim to determine the influence of opioid administration on minute ventilation on spontaneously breathing patients during post-anesthesia care unit (PACU) stay.

This study will evaluate whether quantitative pupillometry measurements can be used to identify children at risk for postoperative opioid-induced respiratory depression (OIRD) following tonsillectomy. Opioid-induced respiratory depression is a serious and potentially life-threatening complication that can occur after surgery, and current monitoring approaches are limited in their ability to predict which patients are at highest risk. In this prospective observational cohort study, approximately 300 pediatric patients undergoing tonsillectomy will undergo non-invasive pupillometry measurements at defined perioperative time points, including preoperative, intraoperative, and postoperative periods. Pupillometry measurements will be collected using a commercially available, FDA-regulated infrared pupillometer. These measurements will include pupil size, constriction and dilation velocities, and latency in response to light stimulation. Pupillometry data will be collected for research purposes only and will not be used to guide clinical care or treatment decisions. Standard clinical care will not be altered as part of this study. Clinical outcomes, including the occurrence of postoperative opioid-induced respiratory depression, opioid use, sedation levels, pain scores, and other postoperative events, will be recorded from the medical record. The goal of this study is to evaluate the relationship between pupillary response patterns and the occurrence of postoperative respiratory depression, and to support the development of predictive models that may improve early identification of patients at risk for opioid-related adverse events.