Continuous Pulse Oximetry and Capnography Monitoring for Postoperative Respiratory Depression and Adverse Events

Perioperative adverse events in adult patients with obstructive sleep apnea undergoing ambulatory surgery: An updated systematic review and meta-analysis

BACKGROUND

The suitability of ambulatory surgery for patients with obstructive sleep apnea (OSA) remains controversial. This systematic review and meta-analysis aimed to evaluate the odds of perioperative adverse events in patients with OSA undergoing ambulatory surgery, compared to patients without OSA.

METHODS

Four electronic databases were searched for studies published between January 1, 2011 and July 11, 2023. The inclusion criteria were: adult patients with diagnosed or high-risk of OSA undergoing ambulatory surgery; perioperative adverse events; control group included; general and/or regional anesthesia; and publication on/after February 1, 2011. We calculated effect sizes as odds ratios using a random effects model, and additional sensitivity analyses were conducted.

RESULTS

Seventeen studies (375,389 patients) were included. OSA was associated with an increased odds of same-day admission amongst all surgery types (OR 1.94, 95% CI 1.46-2.59, I2:79%, P < 0.00001, 11 studies, n = 347,342), as well as when only orthopedic surgery was considered (OR 2.68, 95% CI 2.05-3.48, I2:41%, P < 0.00001, 6 studies, n = 132,473). Three studies reported that OSA was strongly associated with prolonged post anesthesia care unit (PACU) length of stay (LOS), while one study reported that the association was not statistically significant. In addition, four studies reported that OSA was associated with postoperative respiratory depression/hypoxia, with one large study on shoulder arthroscopy reporting an almost 5-fold increased odds of pulmonary compromise, 5-fold of myocardial infarction, 3-fold of acute renal failure, and 5-fold of intensive care unit (ICU) admission.

CONCLUSIONS

Ambulatory surgical patients with OSA had almost two-fold higher odds of same-day admission compared to non-OSA patients. Multiple large studies also reported an association of OSA with prolonged PACU LOS, respiratory complications, and/or ICU admission. Clinicians should screen preoperatively for OSA, optimize comorbidities, adhere to clinical algorithm-based management perioperatively, and maintain a high degree of vigilance in the postoperative period.

Implementation of Continuous Capnography Protocol in a Postanesthesia Care Unit for Adult Patients at High-risk of Postoperative Respiratory Depression

PURPOSE

This project aimed to implement a continuous capnography protocol in the postanesthesia care unit (PACU) for postoperative adult patients who are at high risk for respiratory failure.

DESIGN

A preintervention and postintervention quality improvement design with retrospective chart reviews evaluated patient demographics (age, weight, body mass index [BMI], perioperative fluid intake and output, use of intraoperative positive-end expiratory pressure), length of surgery, average length of PACU stay, incidence of respiratory events, and adherence to a PACU capnography protocol.

METHODS

Preimplementation data were collected from retrospective chart reviews over a 3-month period. A continuous capnography protocol was implemented for same-day surgery patients with a BMI of 35 kg/m2 or greater and who received general anesthesia. Postimplementation data were collected over 3 months in addition to adherence to the capnography protocol. This was presented using descriptive statistics.

FINDINGS

Age, length of surgery, weight, BMI, perioperative fluid intake and output, and use of positive-end expiratory pressure did not impact PACU length of stay. The average PACU length of stay decreased from 76.76 to 71.82 minutes postimplementation but was not statistically significant (P = .470). The incidence of respiratory events was 6% (n = 3). After the implementation of the continuous capnography protocol, adherence to the continuous capnography monitoring was 86% (n = 43).

CONCLUSIONS

Patients who are at high risk for postoperative respiratory failure may benefit from continuous capnography monitoring in the PACU. Capnography monitoring may decrease PACU length of stay and provide earlier detection of pending respiratory depression or failure than pulse oximetry alone.

Executive Summary of the Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR) Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management

The Airway section of the Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) present the Guidelines for the integral management of difficult airway in adult patients. This document provides recommendations based on current scientific evidence, theoretical-educational tools and implementation tools, mainly cognitive aids, applicable to the treatment of the airway in the field of anesthesiology, critical care, emergencies and prehospital medicine. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations and optimization in the progression of the application of strategies to preserve adequate alveolar oxygenation in order to improve safety and quality of care.

Pro-Con Debate: Universal Versus Selective Continuous Monitoring of Postoperative Patients

In this Pro-Con commentary article, we discuss use of continuous physiologic monitoring for clinical deterioration, specifically respiratory depression in the postoperative population. The Pro position advocates for 24/7 continuous surveillance monitoring of all patients starting in the postanesthesia care unit until discharge from the hospital. The strongest arguments for universal monitoring relate to inadequate assessment and algorithms for patient risk. We argue that the need for hospitalization in and of itself is a sufficient predictor of an individual's risk for unexpected respiratory deterioration. In addition, general care units carry the added risk that even the most severe respiratory events will not be recognized in a timely fashion, largely due to higher patient to nurse staffing ratios and limited intermittent vital signs assessments (e.g., every 4 hours). Continuous monitoring configured properly using a "surveillance model" can adequately detect patients' respiratory deterioration while minimizing alarm fatigue and the costs of the surveillance systems. The Con position advocates for a mixed approach of time-limited continuous pulse oximetry monitoring for all patients receiving opioids, with additional remote pulse oximetry monitoring for patients identified as having a high risk of respiratory depression. Alarm fatigue, clinical resource limitations, and cost are the strongest arguments for selective monitoring, which is a more targeted approach. The proponents of the con position acknowledge that postoperative respiratory monitoring is certainly indicated for all patients, but not all patients need the same level of monitoring. The analysis and discussion of each point of view describes who, when, where, and how continuous monitoring should be implemented. Consideration of various system-level factors are addressed, including clinical resource availability, alarm design, system costs, patient and staff acceptance, risk-assessment algorithms, and respiratory event detection. Literature is reviewed, findings are described, and recommendations for design of monitoring systems and implementation of monitoring are described for the pro and con positions.

Obstructive Sleep Apnea and Risk of Postoperative Complications after Non-Cardiac Surgery

Obstructive sleep apnea (OSA), a common sleep disorder, poses significant challenges in perioperative management due to its complexity and multifactorial nature. With a global prevalence of approximately 22.6%, OSA often remains undiagnosed, and increases the risk of cardiac and respiratory postoperative complications. Preoperative screening has become essential in many institutions to identify patients at increased risk, and experts recommend proceeding with surgery in the absence of severe symptoms, albeit with heightened postoperative monitoring. Anesthetic and sedative agents exacerbate upper airway collapsibility and depress central respiratory activity, complicating intraoperative management, especially with neuromuscular blockade use. Additionally, OSA patients are particularly prone to opioid-induced respiratory depression, given their increased sensitivity to opioids and heightened pain perception. Thus, regional anesthesia and multimodal analgesia are strongly advocated to reduce perioperative complication risks. Postoperative care for OSA patients necessitates vigilant monitoring and tailored management strategies, such as supplemental oxygen and Positive Airway Pressure therapy, to minimize cardiorespiratory complications. Health care institutions are increasingly focusing on enhanced monitoring and resource allocation for patient safety. However, the rising prevalence of OSA, heterogeneity in disease severity, and lack of evidence for the efficacy of costly perioperative measures pose challenges. The development of effective screening and monitoring algorithms, alongside reliable risk predictors, is crucial for identifying OSA patients needing extended postoperative care. This review emphasizes a multidimensional approach in managing OSA patients throughout the perioperative period, aiming to optimize patient outcomes and minimize adverse outcomes.

A machine learning algorithm for detecting abnormal patterns in continuous capnography and pulse oximetry monitoring

Continuous capnography monitors patient ventilation but can be susceptible to artifact, resulting in alarm fatigue. Development of smart algorithms may facilitate accurate detection of abnormal ventilation, allowing intervention before patient deterioration. The objective of this analysis was to use machine learning (ML) to classify combined waveforms of continuous capnography and pulse oximetry as normal or abnormal. We used data collected during the observational, prospective PRODIGY trial, in which patients receiving parenteral opioids underwent continuous capnography and pulse oximetry monitoring while on the general care floor [1]. Abnormal ventilation segments in the data stream were reviewed by nine experts and inter-rater agreement was assessed. Abnormal segments were defined as the time series 60s before and 30s after an abnormal pattern was detected. Normal segments (90s continuous monitoring) were randomly sampled and filtered to discard sequences with missing values. Five ML models were trained on extracted features and optimized towards an Fβ score with β = 2. The results show a high inter-rater agreement (> 87%), allowing 7,858 sequences (2,944 abnormal) to be used for model development. Data were divided into 80% training and 20% test sequences. The XGBoost model had the highest Fβ score of 0.94 (with β = 2), showcasing an impressive recall of 0.98 against a precision of 0.83. This study presents a promising advancement in respiratory monitoring, focusing on reducing false alarms and enhancing accuracy of alarm systems. Our algorithm reliably distinguishes normal from abnormal waveforms. More research is needed to define patterns to distinguish abnormal ventilation from artifacts.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Capnography-An Essential Monitor, Everywhere: A Narrative Review

Capnography is now recognized as an indispensable patient safety monitor. Evidence suggests that its use improves outcomes in operating rooms, intensive care units, and emergency departments, as well as in sedation suites, in postanesthesia recovery units, and on general postsurgical wards. Capnography can accurately and rapidly detect respiratory, circulatory, and metabolic derangements. In addition to being useful for diagnosing and managing esophageal intubation, capnography provides crucial information when used for monitoring airway patency and hypoventilation in patients without instrumented airways. Despite its ubiquitous use in high-income-country operating rooms, deaths from esophageal intubations continue to occur in these contexts due to incorrect use or interpretation of capnography. National and international society guidelines on airway management mandate capnography's use during intubations across all hospital areas, and recommend it when ventilation may be impaired, such as during procedural sedation. Nevertheless, capnography's use across high-income-country intensive care units, emergency departments, and postanesthesia recovery units remains inconsistent. While capnography is universally used in high-income-country operating rooms, it remains largely unavailable to anesthesia providers in low- and middle-income countries. This lack of access to capnography likely contributes to more frequent and serious airway events and higher rates of perioperative mortality in low- and middle-income countries. New capnography equipment, which overcomes cost and context barriers, has recently been developed. Increasing access to capnography in low- and middle-income countries must occur to improve patient outcomes and expand universal health care. It is time to extend capnography's safety benefits to all patients, everywhere.

Incidence of postoperative opioid-induced respiratory depression episodes in patients on room air or supplemental oxygen: a post-hoc analysis of the PRODIGY trial

BACKGROUND

Supplemental oxygen (SO) potentiates opioid-induced respiratory depression (OIRD) in experiments on healthy volunteers. Our objective was to examine the relationship between SO and OIRD in patients on surgical units.

METHODS

This post-hoc analysis utilized a portion of the observational PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY (PRODIGY) trial dataset (202 patients, two trial sites), which involved blinded continuous pulse oximetry and capnography monitoring of postsurgical patients on surgical units. OIRD incidence was determined for patients receiving room air (RA), intermittent SO, or continuous SO. Generalized estimating equation (GEE) models, with a Poisson distribution, a log-link function and time of exposure as offset, were used to compare the incidence of OIRD when patients were receiving SO vs RA.

RESULTS

Within the analysis cohort, 74 patients were always on RA, 88 on intermittent and 40 on continuous SO. Compared with when on RA, when receiving SO patients had a higher risk for all OIRD episodes (incidence rate ratio [IRR] 2.7, 95% confidence interval [CI] 1.4-5.1), apnea episodes (IRR 2.8, 95% CI 1.5-5.2), and bradypnea episodes (IRR 3.0, 95% CI 1.2-7.9). Patients with high or intermediate PRODIGY scores had higher IRRs of OIRD episodes when receiving SO, compared with RA (IRR 4.5, 95% CI 2.2-9.6 and IRR 2.3, 95% CI 1.1-4.9, for high and intermediate scores, respectively).

CONCLUSIONS

Despite oxygen desaturation events not differing between SO and RA, SO may clinically promote OIRD. Clinicians should be aware that postoperative patients receiving SO therapy remain at increased risk for apnea and bradypnea.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02811302, registered June 23, 2016.

Ability of the integrated pulmonary index to predict impending respiratory events in the early postoperative period

BACKGROUND

In the early postoperative period, respiratory compromise is a significant problem. Standard-of-care monitoring includes respiratory rate (RR) and pulse oximetry, which are helpful; however, low SpO₂ is often a late sign during decompensation. The FDA-approved Capnostream-20p monitor records four variables (SpO₂, RR, End-tidal CO₂, heart rate), which are combined by fuzzy logic into a single, unit-less value (range 1-10) called the integrated pulmonary index (IPI). No published studies have assessed the performance of a low IPI to predict impending respiratory events.

METHODS

In this investigator-initiated study, adult patients undergoing general anesthesia were monitored with the Capnostream-20p monitor for up to 2 h during their recovery room stay. The study coordinator, who along with clinicians, was blinded to IPI values, recorded the time of any respiratory event, defined a priori as any one of eight respiratory-related interventions/conditions. The primary sensitivity endpoint (early detection success) was defined as at least 80% of events predicted by at least 2 consecutive low IPI (≤ 7) values within 2-15 min before an event occurred. Late detection was defined as low IPI values occurring with 2 min prior to or 2 min after the event occurred.

DISCUSSION

Of 358 patients, ≥ 1 respiratory event occurred in 183 (51.1%) patients. Of 802 total events, 606 were detected early (within 2-15 min prior to the event), and 653 were detected either early or late. Therefore, the sensitivity for early detection was 75.6% (95% confidence interval [CI]: 72.6-78.5%), which differed significantly from the 80% sensitivity goal by 4.4% (p = 0.0016). Sensitivity for total success (early or late) was 81.4% (95% CI: 78.7-84.1%), which was significantly different from the 90% on time sensitivity goal by 8.6% (p < 0.0001).

CONCLUSIONS

A low IPI was 75.6% sensitive for early detection (within 2-15 min) prior to respiratory events but did not achieve our preset threshold of 80% for success.

The EUPEMEN (EUropean PErioperative MEdical Networking) Protocol for Bowel Obstruction: Recommendations for Perioperative Care

Mechanical bowel obstruction is a common symptom for admission to emergency services, diagnosed annually in more than 300,000 patients in the States, from whom 51% will undergo emergency laparotomy. This condition is associated with serious morbidity and mortality, but it also causes a high financial burden due to long hospital stay. The EUPEMEN project aims to incorporate the expertise and clinical experience of national clinical specialists into development of perioperative rehabilitation protocols. Providing special recommendations for all aspects of patient perioperative care and the participation of diverse specialists, the EUPEMEN protocol for bowel obstruction, as presented in the current paper, aims to provide faster postoperative recovery and reduce length of hospital stay, postoperative morbidity and mortality rate.

Wearable device for prevention of postoperative and post-discharge hypoxemia: A randomized pilot trial

BACKGROUND

The Oxalert Enhanced Pulse Oximeter (EPO) is a wearable device that detects and alerts patients to hypoxemia. In a preplanned pilot trial, we estimated the effect of continuous saturation monitoring with patient alerts on in-hospital and post-discharge saturation; we further assessed the feasibility of the intervention.

METHODS

Noncardiac surgical patients were randomized to either the Oxalert with patient alerts (Monitor + Alert, N = 25) or the Oxalert without patient alerts (Monitor Only, N = 24). Monitoring continued during hospitalization for up to 6 days and for 24 h after hospital discharge. Patients in each group were compared on time-weighted average (TWA) SpO2 <90% (%) and area under SpO2 <90% (% * min) in-hospital and after discharge using the Wilcoxon rank sum test, with the treatment effect median difference and 95% confidence interval (CI) estimated using the Hodges-Lehmann estimator of location shift.

RESULTS

We enrolled ≥2 patients per week, for a total of 49 patients in whom recording were obtained for a median [quartiles] of 91 [85, 95]% of the time in hospital. In-hospital, TWA SpO2 <90% was a median [quartiles] of 0.11 [0.03, 0.25]% for Monitor + Alert and 0.29 [0.04, 0.71]% for Monitor-Only patients, with estimated median difference (95% CI) of -0.1 (-0.4, 0)%, p = .120. In hospital, the area under the curve (AUC) SpO2 <90% was a median [quartiles] of 635 [204, 1513] % * min for Monitor + Alert and 1260 [117, 5278] % * min for Monitor-Only patients, with estimated median difference (95% CI) of -407 (-1816, 208) % * min, p = .349. Post-discharge, the estimated median difference (95% CI) was only -0.1 (-0.2, 0) %, p = .307.

CONCLUSIONS

The Oxalert system was well tolerated in both groups and enrollment was strong. Patients randomized to active Oxalert systems experienced half as many postoperative desaturation events while hospitalized, although the difference was not statistically significant in this small pilot trial. In contrast, the Oxalert system did not reduce post-discharge desaturation. Detecting postoperative deterioation in surgical patients after they arrive on regular hospital wards, and even after they have been discharged home, can potentially facilitate necessary "rescue" interventions. Wearable devices assessing vital signs, including oxygenation, are a practical requirement. In this pilot study, a wearable pulse oximeter, with and without hypoxemia alarms, was tested for feasibility and acceptability for signal collection in postoperative cases, including at home. Results indicate that a full-scale trial is warranted to test for possible clinical benefit with this type of "wearable" where late postoperative hypoxia could be a concern. The trial was registered at ClincialTrial.gov (NCT04453722).

Free-living core body temperature monitoring using a wrist-worn sensor after COVID-19 booster vaccination: a pilot study

Core body temperature (CBT) is a key vital sign and fever is an important indicator of disease. In the past decade, there has been growing interest for vital sign monitoring technology that may be embedded in wearable devices, and the COVID-19 pandemic has highlighted the need for remote patient monitoring systems. While wrist-worn sensors allow continuous assessment of heart rate and oxygen saturation, reliable measurement of CBT at the wrist remains challenging. In this study, CBT was measured continuously in a free-living setting using a novel technology worn at the wrist and compared to reference core body temperature measurements, i.e., CBT values acquired with an ingestible temperature-sensing pill. Fifty individuals who received the COVID-19 booster vaccination were included. The datasets of 33 individuals were used to develop the CBT prediction algorithm, and the algorithm was then validated on the datasets of 17 participants. Mean observation time was 26.4 h and CBT > 38.0 °C occurred in 66% of the participants. CBT predicted by the wrist-worn sensor showed good correlation to the reference CBT (r = 0.72). Bland-Altman statistics showed an average bias of 0.11 °C of CBT predicted by the wrist-worn device compared to reference CBT, and limits of agreement were - 0.67 to + 0.93 °C, which is comparable to the bias and limits of agreement of commonly used tympanic membrane thermometers. The small size of the components needed for this technology would allow its integration into a variety of wearable monitoring systems assessing other vital signs and at the same time allowing maximal freedom of movement to the user.

Hypoventilation in the PACU is associated with hypoventilation in the surgical ward: Post-hoc analysis of a randomized clinical trial

OBJECTIVE

To evaluate the association between early postoperative hypoventilation in the last hour of the post-anesthesia care unit (PACU) stay and hypoventilation during the rest of the first 48 postoperative hours in the surgical ward.

DESIGN

Sub-analysis of a clinical trial.

SETTING

PACU and surgical wards of a single medical center.

PATIENTS

Adults having abdominal surgery under general anesthesia.

INTERVENTIONS

Monitoring with a respiratory volume monitor from admission to PACU until the earlier of 48 h after surgery or discharge.

MEASUREMENTS

The exposure was having at least one low minute-ventilation (MV) event during the last hour of PACU stay, defined as MV lower than 40% the predicted value lasting at least 1 min. The primary outcome was low MV events lasting at least 2 min during the rest of the first 48 postoperative hours, while in the surgical ward. The secondary outcome was the rate of low MV events per monitored hour.

MAIN RESULTS

Data of 292 patients were analyzed, of which 20 (6.8%) patients had a low MV event in PACU. Low MV events in the surgical ward were found in 81 (28%) patients. All patients who had low MV events in PACU had events again in the ward, while 61/272 (22%) had an event in the ward but not in PACU. The incidence rate of low MV events per hour was 24 (95% CI: 13, 46) among patients having an event in the PACU, and 2 (1, 4) among those who did not.

CONCLUSIONS

In adults recovering from abdominal surgery, events of hypoventilation during the first postoperative hour are associated with similar events during the rest of the first 48 postoperative hours, with positive predictive value approaching 100%. Sixty-one patients had ward hypoventilation that was not preceded by hypoventilation in PACU.

Perioperative management of obstructive sleep apnea in lower extremity orthopedic procedures: A review of evidence to inform the development of a clinical pathway

Obstructive sleep apnea (OSA) is unrecognized in as high as 80% of patients before surgery. When untreated, OSA increases a surgical patient's propensity for airway collapse and sleep deprivation lending to a higher risk for emergent re-intubation, prolonged recovery time, escalation of care, hospital readmission, and longer length of stay. We have reviewed the evidence regarding diagnostic performance of OSA screening methods and the impact of perioperative management strategies on postoperative complications among patients with diagnosed or suspected OSA who are undergoing orthopedic surgery. We then integrated the data and recommendations from professional society guidelines to develop an evidence-based clinical care pathway to optimize the perioperative management of this surgical population. Successful management of patients with diagnosed or suspected OSA encompass five facets of care: screening, education, airway management, medications, and monitoring. This narrative review revealed two gaps in the evidence to inform management of patients undergoing orthopedic surgery 1) during the perioperative setting to include evidence-based interventions that reduce postoperative complications and 2) after discharge to an unmonitored environment. The clinical care pathway as well as perspectives for future research are discussed.

Nocturnal respiratory abnormalities among ward-level postoperative patients as detected by the Capnostream 20p monitor: A blinded observational study

PURPOSE

This prospective observational study aimed to establish the frequency of postoperative nocturnal respiratory abnormalities among patients undergoing major surgery who received ward-level care. These abnormalities may have implications for postoperative pulmonary complications (PPCs).

METHODS

Eligible patients underwent blinded noninvasive continuous capnography with pulse oximetry using the Capnostream™ 20p monitor over the first postoperative night. All patients received oxygen supplementation and patient-controlled opioid analgesia. The primary outcome was the number of prolonged apnea events (PAEs), defined as end-tidal carbon dioxide (EtCO2) ≤5 mmHg for 30-120 seconds or EtCO2 ≤5 mmHg for >120 seconds with oxygen saturation (SpO2) <85%. Secondary outcomes were the proportion of recorded time that physiological indices were aberrant, including the apnea index (AI), oxygen desaturation index (ODI), integrated pulmonary index (IPI), and SpO2. Exploratory analysis was conducted to assess the associations between PAEs, PPCs, and pre-defined factors.

RESULTS

Among 125 patients who had sufficient data for analysis, a total of 1800 PAEs occurred in 67 (53.4%) patients. The highest quartile accounted for 89.1% of all events. Amongst patients who experienced any PAEs, the median (IQR) number of PAE/patient was four (2-12). As proportions of recorded time (median (IQR)), AI, ODI, and IPI were aberrant for 12.4% (0-43.2%), 19.1% (2.0-57.1%), and 11.5% (3.1-33.3%) respectively. Only age, ARISCAT, and opioid consumption/kg were associated with PPCs.

CONCLUSIONS

PAE and aberrant indices were frequently detected on the first postoperative night. However, they did not correlate with PPCs. Future research should investigate the significance of detected aberrations.

Respiratory Monitoring after Opioid-Sparing Bariatric Surgery in Patients with Obstructive Sleep Apnea (OSA)

Introduction with Aim: Postoperative respiratory depression can complicate a patient’s recovery after surgery. A predictive score (PRODIGY) was recently proposed to evaluate the risk of opioid-induced postoperative respiratory depression. For the first time, we applied this score to a cohort of patients receiving bariatric surgery, stratified by Obstructive Sleep Apnea (OSA) status. In addition, we recorded continuous postoperative capnography to evaluate respiratory depression and apnea episodes (Respiratory Events, RE). Materials and Methods: The present study was approved by our IRB and comprised continuous surveillance of respiratory variables during postoperative recovery (in PACU) after robotic bariatric surgery. We utilized continuous capnography and pulse oximetry (Capnostream 35, Medtronic Inc., and Profox Respiratory Oximetry software). Preoperative preparation included OSA evaluation for all bariatric patients, additional sleep studies for severe OSA grades, and evaluation of risk for respiratory depression (low, intermediate, or high) using the published PRODIGY score. In addition, we evaluated patients by OSA status. All patients received multimodal intraoperative non-opioid anesthesia from the same team. After surgery, all patients received continuous respiratory surveillance in PACU (average duration exceeding 140 min). Respiratory depression events were scored using a modified list of the five standard published categories. Events were measured according to analysis of continuously recorded tracing of the compiled respiratory variables by observers kept blind from the study patient’s group. Results: Of the 80 patients evaluated (18 male), 56 had obstructive sleep apnea and were using CPAP at home (OSA); 24 did not. OSA patients received CPAP via an oronasal mask or a nasal pillow pressure support immediately after arriving in PACU, utilizing their at-home settings. We encountered 115 respiratory depression events across 48 patients. The most frequent respiratory event recorded was a transient desaturation (as low as 85%), which usually lasted 20–30 sec and resolved spontaneously in 3 to 5 min; most episodes followed small boluses of IV opioid analgesia administered during recovery, on demand. All episodes resolved spontaneously without any nursing or medical intervention. OSA patients had significantly more events than non-OSA patients (1.84 (1.78–1.9) mean events vs. 0.50 (0.43–0.57) for non-OSA, p = 0.0002). The level of PRODIGY score (low, intermediate, or high), instead, was not predictive of the number of events when we treated this variable as continuous (p = 0.39) or categorical (high vs. low, p = 0.65, and intermediate vs. low, p = 0.17). Conclusions: We attribute these novel results, showing a lack of respiratory events requiring intervention, to opioid-free anesthesia, early CPAP utilization, and head-up positioning on admission to PACU. Furthermore, all these patients had light postoperative narcotic requirements. Finally, an elevated PRODIGY score in our patients did not sufficiently predict respiratory events, but OSA status alone did. Key Points Summary: We investigated the incidence of Respiratory Events (RE) in Obstructive Sleep Apnea patients after surgery (56 patients) and compared them to similar patients without OSA (24 patients). All patients received identical robotic-assisted surgery and low- or no-opiate anesthesia. Patients were pre-screened with the standard published PRODIGY scores and were monitored after PACU arrival with continuous oximetry and capnography (Capnostream 35 and Profox analysis). OSA patients showed more RE than non-OSA (1.8 vs. 0.5, p = −0.0002). However, patients with elevated PRODIGY scores did not develop more frequent RE compared to patients with low scores. We attribute these novel results to opioid-sparing anesthesia/analgesia and immediate CPAP utilization on admission to PACU.

The effect of hyperoxia on ventilation during recovery from general anesthesia: A randomized pilot study for a parallel randomized controlled trial

STUDY OBJECTIVE

While supplemental O₂ inhalation corrects hypoxemia, its effect on post-anesthesia ventilation remains unknown. This pilot trial tested the hypothesis that hyperoxia increases the time spent with a transcutaneous PCO₂ (TcPCO₂) > 45 mmHg, compared with standard O₂ supplementation.

DESIGN

Single-blinded, parallel two-arm randomized pilot trial.

SETTING

University hospital.

PATIENTS

20 patients undergoing robotic-assisted laparoscopic nephrectomy.

MEASUREMENTS

After institutional approval and informed consent, patients were randomized to receive O₂ titrated to arterial saturation (SpO₂): 90-94% (Conservative O₂, N =10), or to SpO₂ > 96% (Liberal O₂, N = 10) for up to 90 min after anesthesia. Continuous TcPCO₂, respiratory inductance plethysmography (RIP), and SpO₂, were recorded. We calculated the percentage of time at TcPCO₂ > 45 mmHg for each patient and compared the two groups using analysis of covariance, adjusting for sex, age, and body mass index. We also estimated the sample size required to detect the between-group difference observed in this pilot trial. RIP signals were used to calculate apnea/hypopnea index (AHI), which was then compared between two groups.

MAIN RESULTS

The mean percentage of time with a TcPCO₂ > 45 mmHg was 80.6% for the Conservative O₂ (N=9) and 61.2% for the Liberal O₂ (N=10) group [between-group difference of 19.4% (95% CI: -18.7% to 57.6%), P = 0.140]. With an observed effect size of 0.73, we estimated that 30 participants per group are required, to demonstrate this difference with a power of 80% at a two-sided alpha of 5%. Means SpO₂ were 94.5% and 99.9% for the Conservative O₂ and the Liberal O₂ groups, respectively. AHI was significantly higher in the Conservative O₂, compared with the Liberal O₂ group (median AHI: 16 vs. 3; P = 0.0014).

CONCLUSIONS

Hyperoxia in the post-anesthesia period reduced the time spent at TcPCO₂ > 45 mmHg and significantly decreased AHI, while mean SpO₂ ranged inside the a priori defined limits.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04723433.

Regional respiratory sound abnormalities in pneumothorax and pleural effusion detected via respiratory sound visualization and quantification: case report

Assessment of respiratory sounds by auscultation with a conventional stethoscope is subjective. We developed a continuous monitoring and visualization system that enables objectively and quantitatively visualizing respiratory sounds. We herein present two cases in which the system showed regional differences in the respiratory sounds. We applied our novel continuous monitoring and visualization system to evaluate respiratory abnormalities in patients with acute chest disorders. Respiratory sounds were continuously recorded to assess regional changes in respiratory sound volumes. Because we used this system as a pilot study, the results were not shown in real time and were retrospectively analyzed. Case 1 An 89-year-old woman was admitted to our hospital for sudden-onset respiratory distress and hypoxia. Chest X-rays revealed left pneumothorax; thus, we drained the thorax. After confirming that the pneumothorax had improved, we attached the continuous monitoring and visualization system. Chest X-rays taken the next day showed exacerbation of the pneumothorax. Visual and quantitative findings showed a decreased respiratory volume in the left lung after 3 h. Case 2 A 94-year-old woman was admitted to our hospital for dyspnea. Chest X-rays showed a large amount of pleural effusion on the right side. The continuous monitoring and visualization system visually and quantitatively revealed a decreased respiratory volume in the lower right lung field compared with that in the lower left lung field. Our newly developed continuous monitoring and visualization system enabled quantitatively and visually detecting regional differences in respiratory sounds in patients with pneumothorax and pleural effusion.

An Educational Intervention to Improve Comfort with Applying and Interpreting Transcutaneous CO2 and End-tidal CO2 Monitoring in the PACU

PURPOSE

The purpose of this study was to assess the effectiveness of an educational program about measuring ventilation using devices that assess carbon dioxide levels in patients recovering from a surgical procedure.

DESIGN

A pre-post survey of knowledge attainment from an educational intervention about measuring ventilation using end-tidal carbon dioxide (EtCO₂) and transcutaneous carbon dioxide (tcPCO₂) devices in the postanesthesia care unit (PACU) was distributed to current members of the American Society of PeriAnesthesia Nurses.

METHODS

Participants received a 12-question pre-intervention (five were related to demographics) and a five-question post-intervention survey. Non-demographic survey questions used a one to five Likert scale to assess comfortability or confidence. The intervention created was a voice-over presentation designed to improve PACU RN's comfort and confidence with using and interpreting tcPCO₂ or EtCO₂ in the PACU.

FINDINGS

PACU RNs (N = 108) reported they 'never' or 'rarely' used EtCO₂ (n = 57, 52.7%) monitoring or tcPCO₂ (n = 93, 86.1%) monitoring in the PACU. A paired t test revealed statistically significant differences in the PACU RN's pre-survey and posttest comfortability of applying and interpreting EtCO₂ or tcPCO₂ monitors (P < .05).

CONCLUSIONS

Capnography monitoring should be considered a standard of care for PACU patients. Education of registered nurses working in the PACU is critical before implementing EtCO₂ or tcPCO₂ monitoring.

Validation of the STOP-Bang questionnaire as a preoperative screening tool for obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder that is highly associated with postoperative complications. The STOP-Bang questionnaire is a simple screening tool for OSA. The objective of this systematic review and meta-analysis is to evaluate the validity of the STOP-Bang questionnaire for screening OSA in the surgical population cohort.

METHODS

A systematic search of the following databases was performed from 2008 to May 2021: MEDLINE, Medline-in-process, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO, Journals @ Ovid, Web of Science, Scopus, and CINAHL. Continued literature surveillance was performed through October 2021.

RESULTS

The systematic search identified 4641 articles, from which 10 studies with 3247 surgical participants were included in the final analysis. The mean age was 57.3 ± 15.2 years, and the mean BMI was 32.5 ± 10.1 kg/m² with 47.4% male. The prevalence of all, moderate-to-severe, and severe OSA were 65.2, 37.7, and 17.0%, respectively. The pooled sensitivity of the STOP-Bang questionnaire for all, moderate-to-severe, and severe OSA was 85, 88, and 90%, and the pooled specificities were 47, 29, and 27%, respectively. The area under the curve for all, moderate-to-severe, and severe OSA was 0.84, 0.67, and 0.63.

CONCLUSIONS

In the preoperative setting, the STOP-Bang questionnaire is a valid screening tool to detect OSA in patients undergoing surgery, with a high sensitivity and a high discriminative power to reasonably exclude severe OSA with a negative predictive value of 93.2%.

TRIAL REGISTRATION

PROSPERO registration  CRD42021260451 .

VOLUMETRIC CAPNOGRAPHY FOR RESPIRATORY MONITORING OF PATIENTS DURING ROUTINE COLONOSCOPY WITH ROOM-AIR AND CARBON DIOXIDE INSUFFLATION

BACKGROUND

Capnography and carbon dioxide (CO2) insufflation during gastrointestinal endoscopy under sedation are associated with safety and comfort improvements, respectively. Capnography can provide early detection of apnea and hypoxemia, whereas CO2 insufflation causes lower periprocedural discomfort. This is the first study to report the application of volumetric capnography in colonoscopy.

OBJECTIVE

This study aimed to evaluate the use of volumetric capnography with room air (RA) and CO2 insufflation during routine colonoscopy.

METHODS

In this prospective cohort study, 101 patients who underwent routine colonoscopy under sedation with volumetric capnography monitoring were included. Insufflation with RA was used to distend the intestinal lumen in group 1 (n=51), while group 2 (n=50) used CO2 insufflation. The primary endpoints were episodes of hypoxia, alveolar hypoventilation, and end-tidal CO2 (EtCO2). The secondary endpoints were tidal volume per minute, consumption of sedation medications, and post-procedure pain using the Gloucester modified pain scale.

RESULTS

The number of episodes of hypoxia (SpO2<90%) was similar between the groups: four episodes in Group 1 and two episodes in Group 2. The duration of hypoxia was significantly longer in group 2 (P=0.02). Hypoalveolar ventilation (EtCO2) occurred more frequently in Group 2 than in Group 1 (27 vs 18 episodes, P=0.05). Regarding EtCO2, Group 2 showed higher values in cecal evaluation (28.94±4.68 mmHg vs 26.65±6.12 mmHg, P=0.04). Regarding tidal volume per minute, Group 2 had significantly lower values at the cecal interval compared to Group 1 (2027.53±2818.89 vs 970.88±1840.25 L/min, P=0.009). No episodes of hypercapnia (EtCO2 > 60 mmHg) occurred during the study. There was no difference in the consumption of sedation medications between the groups. Immediately after colonoscopy, Group 2 reported significantly less pain than Group 1 (P=0.05).

CONCLUSION

In our study, volumetric capnography during colonoscopy was feasible and effective for monitoring ventilatory parameters and detecting respiratory complications. CO2 insufflation was safe and associated with less pain immediately after colonoscopy.

The evidence base for US joint commission hospital accreditation standards: cross sectional study

OBJECTIVE

To evaluate the evidence upon which standards for hospital accreditation by The Joint Commission on Accreditation of Healthcare Organizations (the Joint Commission) are based.

DESIGN

Cross sectional study.

SETTING

United States.

PARTICIPANTS

Four Joint Commission R3 (requirement, rationale, and reference) reports released by July 2018 and intended to become effective between 1 July 2018 and 1 July 2019.

INTERVENTIONS

From each R3 report the associated standard and its specific elements of performance (or actionable standards) were extracted. If an actionable standard enumerated multiple requirements, these were separated into distinct components. Two investigators reviewed full text references, and each actionable standard was classified as either completely supported, partly supported, or not supported; Oxford evidence quality ratings were assigned; and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess the strength of recommendations.

MAIN OUTCOME MEASURE

Strengths of recommendation for actionable standards.

RESULTS

20 actionable standards with 76 distinct components were accompanied by 48 references. Of the 20 actionable standards, six (30%) were completely supported by cited references, six were partly supported (30%), and eight (40%) were not supported. Of the six directly supported actionable standards, one (17%) cited at least one reference of level 1 or 2 evidence, none cited at least one reference of level 3 evidence, and five (83%) cited references of level 4 or 5 evidence. Of the completely supported actionable standards, strength of recommendation in five was deemed GRADE D and in one was GRADE B.

CONCLUSIONS

In general, recent actionable standards issued by The Joint Commission are seldom supported by high quality data referenced within the issuing documents. The Joint Commission might consider being more transparent about the quality of evidence and underlying rationale supporting each of its recommendations, including clarifying when and why in certain instances it determines that lower level evidence is sufficient.

Opioid abuse and perioperative care: a new medical disease

PURPOSE OF REVIEW

This review article aims to describe the perioperative clinical implications of opioid use or opioid use disorder (OUD) and to provide recommendations related to analgesia, anesthesia, and postoperative care for patients with this 'new medical disease'.

RECENT FINDINGS

Evidence suggest that 1 in 4 surgical patients will be using opioids preoperatively. Management of these patients, or those with OUD, can be challenging given their opioid tolerance, hyperalgesia, decreased pain tolerance, and increased pain sensitivity. Therefore, an individualized plan that considers how to manage OUD treatment medications, the risk of relapse, multimodal analgesia, and postoperative monitoring requirements is highly important. Fortunately, recent publications provide both insight and guidance on these topics. Postoperatively, persistent opioid utilization appears higher in patients currently using opioids and even for those with a prior history. Although numerous other adverse outcomes are also associated with opioid use or abuse, some may be modifiable with cessation.

SUMMARY

A coordinated, evidence-based, multidisciplinary team approach is critical when caring for patients with OUD to ensure safety, provide adequate analgesia, and reduce the risk of relapse. Enhanced postoperative monitoring, multimodal analgesia, and a plan for preoperative opioid management may help to modify the risks of adverse postoperative outcomes.

Undetected Respiratory Depression in People with Opioid Use Disorder

BACKGROUND

Opioid-related deaths are increasing globally. Respiratory complications of opioid use and underlying respiratory disease in people with Opioid Use Disorder (OUD) are potential contributory factors. Individual variation in susceptibility to overdose is, however, incompletely understood. This study investigated the prevalence of respiratory depression (RD) in OUD treatment and compared this to patients with chronic obstructive pulmonary disease (COPD) of equivalent severity. We also explored the contribution of opioid agonist treatment (OAT) dosage, and type, to the prevalence of RD.

METHODS

There were four groups of participants: 1) OUD plus COPD ('OUD-COPD', n = 13); 2) OUD without COPD ('OUD', n = 7); 3) opioid-naïve COPD patients ('COPD'n = 13); 4) healthy controls ('HC'n = 7). Physiological indices, including pulse oximetry (SpO₂%), end-tidal CO₂ (ETCO₂), transcutaneous CO₂ (TcCO₂), respiratory airflow and second intercostal space parasternal muscle electromyography (EMG_para), were recorded continuously over 40 min whilst awake at rest. Significant RD was defined as: SpO₂%< 90% for > 10 s, ETCO₂ per breath > 6.6 kPa, TcCO₂ overall mean > 6 kPa, respiratory pauses > 10 s RESULTS: At least one indicator was observed in every participant with OUD (n = 20). This compared to RD episode occurrence in only 2/7 HC and 2/13 COPD participants (p < 0.05,Fisher's exact test). The occurrence of RD was similar in OUD participants prescribed methadone (n = 6) compared to those prescribed buprenorphine (n = 12).

CONCLUSIONS

Undetected RD is common in OUD cohorts receiving OAT and is significantly more severe than in opioid-naïve controls. RD can be assessed using simple objective measures. Further studies are required to determine the association between RD and overdose risk.

Current and Future Perspective of Devices and Diagnostics for Opioid and OIRD

OIRD (opioid-induced respiratory depression) remains a significant public health concern due to clinically indicated and illicit opioid use. Respiratory depression is the sine qua non of opioid toxicity, and early detection is critical for reversal using pharmacologic and non-pharmacologic interventions. In addition to respiratory monitoring devices such as pulse oximetry, capnography, and contactless monitoring systems, novel implantable sensors and detection systems such as optical detection and electrochemical detection techniques are being developed to identify the presence of opioids both in vivo and within the environment. These new technologies will not only monitor for signs and symptoms of OIRD but also serve as a mechanism to alert and assist first responders and lay rescuers. The current opioid epidemic brings to the forefront the need for additional accessible means of detection and diagnosis. Rigorous evaluation of safety, efficacy, and acceptability will be necessary for both new and established technologies to have an impact on morbidity and mortality associated with opioid toxicity. Here, we summarized existing and advanced technologies for opioid detection and OIRD management with a focus on recent advancements in wearable and implantable opioid detection. We expect that this review will serve as a complete informative reference for the researchers and healthcare professionals working on the subject and allied fields.

Wireless wearables for postoperative surveillance on surgical wards: a survey of 1158 anaesthesiologists in Western Europe and the USA

Background

Several continuous monitoring solutions, including wireless wearable sensors, are available or being developed to improve patient surveillance on surgical wards. We designed a survey to understand the current perception and expectations of anaesthesiologists who, as perioperative physicians, are increasingly involved in postoperative care.

Methods

The survey was shared in 40 university hospitals from Western Europe and the USA.

Results

From 5744 anaesthesiologists who received the survey link, there were 1158 valid questionnaires available for analysis. Current postoperative surveillance was mainly based on intermittent spot-checks of vital signs every 4-6 h in the USA (72%) and every 8-12 h in Europe (53%). A majority of respondents (91%) considered that continuous monitoring of vital signs should be available on surgical wards and that wireless sensors are preferable to tethered systems (86%). Most respondents indicated that oxygen saturation (93%), heart rate (80%), and blood pressure (71%) should be continuously monitored with wrist devices (71%) or skin adhesive patches (54%). They believed it may help detect clinical deterioration earlier (90%), decrease rescue interventions (59%), and decrease hospital mortality (54%). Opinions diverged regarding the impact on nurse workload (increase 46%, decrease 39%), and most respondents considered that the biggest implementation challenges are economic (79%) and connectivity issues (64%).

Conclusion

Continuous monitoring of vital signs with wireless sensors is wanted by most anaesthesiologists from university hospitals in Western Europe and in the USA. They believe it may improve patient safety and outcome, but may also be challenging to implement because of cost and connectivity issues.

Clinical implications of opioid-induced ventilatory impairment

Opioid-induced ventilatory impairment is the primary mechanism of harm from opioid use. Opioids suppress the activity of the central respiratory centres and are sedating, leading to impairment of alveolar ventilation.Respiratory physiological changes induced with acute opioid use include depression of the hypercapnic ventilatory response and hypoxic ventilatory response. In chronic opioid use a compensatory increase in hypoxic ventilatory response maintains ventilation and contributes to the onset of sleep-disordered breathing patterns of central sleep apnoea and ataxic breathing. Supplemental oxygen use in those at risk of opioid-induced ventilatory impairment requires careful consideration by the clinician to prevent failure to detect hypoventilation, if oximetry is being relied on, and the overriding of hypoxic ventilatory drive. Obstructive sleep apnoea and opioid-induced ventilatory impairment are frequently associated, with this interrelationship being complex and often unpredictable. Monitoring the patient for opioid-induced ventilatory impairment poses challenges in the areas of reliability, avoidance of alarm fatigue, cost, and personnel demands. Many situations remain in which patients cannot be provided effective analgesia without opioids, and for these the clinician requires a comprehensive knowledge of opioid-induced ventilatory impairment.

Current Issues in the Use of Opioids for the Management of Postoperative Pain: A Review

Importance

Uncontrolled and indiscriminate prescribing of opioids has led to an opioid crisis that started in North America and spread throughout high-income countries. The aim of this narrative review was to explore some of the current issues surrounding the use of opioids in the perioperative period, focusing on drivers that led to escalation of use, patient harms, the move away from using self-reported pain scores alone to assess adequacy of analgesia, concerns about the routine use of controlled-release opioids for the management of acute pain, opioid-free anesthesia and analgesia, and prescription of opioids on discharge from hospital.

Observations

The origins of the opioid crisis are multifactorial and may include good intentions to keep patients pain free in the postoperative period. Assessment of patient function may be better than unidimensional numerical pain scores to help guide postoperative analgesia. Immediate-release opioids can be titrated more easily to match analgesic requirements. There is currently no good evidence to show that opioid-free anesthesia and analgesia affects opioid prescribing practices or the risk of persistent postoperative opioid use. Attention should be paid to discharge opioid prescribing as repeat and refill prescriptions are risk-factors for persistent postoperative opioid use. Opioid stewardship is paramount, and many governments are passing legislation, while statutory bodies and professional societies are providing advice and guidance to help mitigate the harm caused by opioids.

Conclusions and Relevance

Opioids remain a crucial part of many patients' journey from surgery to full recovery. The last few decades have shown that unfettered opioid use puts patients and societies at risk, so caution is needed to mitigate those dangers. Opioid stewardship provides a multilayered structure to allow continued safe use of opioids as part of broad pain management strategies for those patients who benefit from them most.

Preventing Postoperative Opioid-Induced Respiratory Depression Through Implementation of an Enhanced Monitoring Program

BACKGROUND

Opioid-induced respiratory depression (OIRD) is a serious complication that can lead to negative outcomes. There are known risk factors for OIRD; however, a lack of national guidelines for the prevention and early detection of OIRD exists.

METHODS

An evidence-based practice study was conducted to create an enhanced monitoring (EM) program. The EM program consisted of risk stratification of surgical spine patients, including the use of STOP-BANG screening for obstructive sleep apnea, capnography monitoring, use of home positive airway pressure therapy, capnography alarm optimization, hospitalist consultation, nursing education, and patient education.

RESULTS

Approximately 17% (N = 937/5,462) of surgical spine patients were enrolled in the EM program. Fifty-six percent of EM patients were monitored with capnography and had out of range end-tidal carbon dioxide levels 17% of the time. The rate of transfers to the intensive care unit (ICU) for OIRD decreased, though not statistically significant (p = .151).

CONCLUSIONS

The EM program with risk stratification was found to reduce transfers to the ICU for OIRD. Although not statistically significant, the decreased number of transfers was clinically significant. Engagement of the interprofessional team and capnography alarm parameter optimization helped to reduce nonactionable alarms.

Impact of a continuous enhanced cardio-respiratory monitoring pathway on cardio-respiratory complications after bariatric surgery: A retrospective cohort study

STUDY OBJECTIVE

To determine the impact of an enhanced monitoring pathway consisting of continuous postoperative cardio-respiratory monitoring on adverse outcomes after bariatric.

DESIGN

Single-center, retrospective cohort study.

PATIENTS

Adult patients who underwent bariatric surgeries between 2009 and 2016.

INTERVENTIONS

We evaluated the use of an enhanced monitoring pathway consisting of a distant, continuous, non-invasive respiratory monitoring system on postoperative cardio-respiratory complications in patients undergoing bariatric surgery. Treating physicians had the option to assign patients to enhanced monitoring (intervention group) in the postoperative period for suspected or diagnosed OSA or other clinical concerns. The control group had intermittent vital sign checks as per institutional standards.

MEASUREMENTS

The primary outcome was a composite of cardio-respiratory complications (rapid response team activation, intensive care admission, respiratory complications), major adverse cardiac events, and all-cause mortality. The secondary outcome was length of stay (LOS).

MAIN RESULTS

Of 1450 patients, 752 patients received enhanced monitoring (intervention) and 698 patients received standard monitoring (control). Univariate analysis showed that, compared to control, enhanced monitoring was associated with lower odds of composite cardio-respiratory complications (OR: 0.41, 95%CI: 0.32-0.53, p < 0.001) and lower odds of prolonged LOS > 2 days (OR: 0.37, 95% CI: 0.28-0.49, p < 0.001. After adjusting for potential confounders, enhanced monitoring remained associated with a reduction in composite cardio-respiratory complications (OR: 0.64, 95% CI: 0.46-0.88, p = 0.005).

CONCLUSIONS

Our study demonstrates that postoperative enhanced monitoring pathway was associated with a lower incidence of cardio-respiratory composite events, compared to a standard of care, in patients undergoing bariatric surgery. As our results show association rather than causation, future prospective randomized trials are needed to confirm the benefit of enhanced monitoring. Findings of our study add to the existing literature involved in clinical management pathways to reduce the incidence of adverse postoperative outcomes in high-risk patients undergoing inpatient surgeries.

Respiration monitoring in PACU using ventilation and gas exchange parameters

The importance of perioperative respiration monitoring is highlighted by high incidences of postoperative respiratory complications unrelated to the original disease. The objectives of this pilot study were to (1) simultaneously acquire respiration rate (RR), tidal volume (TV), minute ventilation (MV), SpO₂ and PetCO₂ from patients in post-anesthesia care unit (PACU) and (2) identify a practical continuous respiration monitoring method by analyzing the acquired data in terms of their ability and reliability in assessing a patient’s respiratory status. Thirteen non-intubated patients completed this observational study. A portable electrical impedance tomography (EIT) device was used to acquire RR_EIT, TV and MV, while PetCO₂, RR_Cap and SpO₂ were measured by a Capnostream35. Hypoventilation and respiratory events, e.g., apnea and hypopnea, could be detected reliably using RR_EIT, TV and MV. PetCO₂ and SpO₂ provided the gas exchange information, but were unable to detect hypoventilation in a timely fashion. Although SpO₂ was stable, the sidestream capnography using the oronasal cannula was often unstable and produced fluctuating PetCO₂ values. The coefficient of determination (R²) value between RR_EIT and RR_Cap was 0.65 with a percentage error of 52.5%. Based on our results, we identified RR, TV, MV and SpO₂ as a set of respiratory parameters for robust continuous respiration monitoring of non-intubated patients. Such a respiration monitor with both ventilation and gas exchange parameters would be reliable and could be useful not only for respiration monitoring, but in making PACU discharge decisions and adjusting opioid dosage on general hospital floor. Future studies are needed to evaluate the potential clinical utility of such an integrated respiration monitor.

Remote transmission monitoring for postoperative perineural analgesia after major orthopedic surgery: A multicenter, randomized, parallel-group, controlled trial

STUDY OBJECTIVE

After surgery, patients reported the delay in receiving help as the primary factor for poorly controlled pain. This study aimed to compare the effectiveness of patient management through two communication modalities: remote transmission (RT) versus bedside control (BC). We hypothesized that using remote technology for pump programming may provide the best postoperative infusion regimen for the patient's self-assessment of pain and adverse events.

DESIGN

A multicenter, randomized, parallel-group, controlled trial.

SETTING

Anesthesiology department and orthopedic surgery ward at three university hospitals.

PATIENTS

Eighty patients undergoing orthopedic surgery with postoperative perineural patient-controlled analgesia were included.

INTERVENTIONS

Two groups (n = 40 for each group) were formed by randomization. In the postoperative period, perineural analgesia was followed up via an RT system or BC for 72 h.

MEASUREMENTS

A nurse assessed daily pain, sensory and motor blocks and adverse events. Patients completed a questionnaire three times a day and alerted for any problem according to the group (RT system or nurses' follow-up). On the third postoperative day, the nurse removed the catheter, completed the final assessment, and collected the historical data from the pump. A physician's shorter response time to change the patient control analgesia (PCA) program was the primary endpoint.

RESULTS

Of the 80 patients, 71 were analyzed (34 were randomized to the RT group and 37 to the BC group). Fifty-eight pump setting changes were noted. Analysis of repeated evaluations shows that mean time (SD) to change the PCA pump settings was significantly lower in the RT group (20 min (22.3 min)) than in the BC group (55.9 min (71.1 min)); mean difference [95% CI], -35.9 min [-74.3 to 2.4]); β estimation [95% CI], -34 [-63 to -6], p = 0.011). Pain relief, sensory and motor blocks did not differ between the groups: β estimation [95% CI], 0.1 [-0.4 to 0.6], p = 0.753; 0.5 [-0.4 to 1.4], p = 0.255; 0.9 [-0.04 to 1.8], p = 0.687, respectively. β = -34 [-63 to -6], p = 0.011). The consumption of ropivacaine, nurse workload and the cost of the analgesia regimen decreased in the RT group. No differences were noted in satisfaction scores or complication rates.

CONCLUSIONS

The response time for the physician to change the PCA program when necessary was shorter for patients using RT and alerts to the physician were more frequent compared with spot checks by nurses. RT helps to decrease nurses' workload, ropivacaine consumption, and costs but did not affect postoperative pain relief, complication rate, or patient-reported satisfaction score.

IRB CONTACT INFORMATION

Comité de Protection des Personnes, Sud Méditerranée III, Montpellier-Nîmes, France, registration number EudraCT A01698-35.

CLINICAL TRIAL NUMBER

ClinicalTrials.gov ID:NCT02018068 PROTOCOL: The full trial protocol can be accessed at Department of Anesthesiology and Critical Care Medicine, Medical Research and Statistics Unit, Lapeyronie University Hospital, Avenue Doten G Giraud, Montpellier, France. s-bringuierbranchereau@chu-montpellier.fr.

Inpatient Respiratory Arrest Associated With Sedative and Analgesic Medications: Impact of Continuous Monitoring on Patient Mortality and Severe Morbidity

OBJECTIVES

The primary study objective was to investigate the impact of surveillance monitoring (i.e., continuous monitoring optimized for deterioration detection) on mortality and severe morbidity associated with administration of sedative/analgesic medications in the general care setting. A second objective was consideration of the results in the context of previous investigations to establish practice recommendations for this approach to patient safety.

METHODS

Retrospective review of available rescue event and patient safety data from a tertiary care hospital in a rural setting was performed for a 10-year period. Systematic analysis of all adult general care inpatient data followed by chart review for individual patients was used to identify patient death or permanent harm (i.e., ventilator dependency, hypoxic encephalopathy) related to administration of sedative/analgesics.

RESULTS

Of 111,488 patients in units with surveillance monitoring available, none died or were harmed by opioid-induced respiratory depression when surveillance monitoring was in use. One patient died from opioid-induced respiratory depression in a unit where surveillance monitoring was available; however, the patient was not monitored at the time of the adverse event. In unmonitored units (15,209 patients during 29 months of incremental implementation), three patients died from opioid overdose (19.73 deaths per 100,000 at risk patients). The reduced death rate when surveillance monitoring was available (0.0009%) versus not available (0.02%) was significant (P = 0.03).

CONCLUSIONS

For a 10-year period, the rescue system with continuous surveillance monitoring had a profound effect on death from sedative/analgesic administration in the general care setting. This approach to patient safety can help address the risk of sedative/analgesic-related respiratory arrests in hospitals.

Wavelet Transform Artificial Intelligence Algorithm-Based Data Mining Technology for Norovirus Monitoring and Early Warning

Norovirus monitoring and early warning can be used for diagnosis without etiological testing, and the treatment of this disease does not require the antibiotics. It often occurs in preschool children and affects their growth and development, so the coping measures for this disease are more prevention than treatment. In this study, the clinical data of 2133 children with diarrhea were collected. Based on the artificial intelligence (AI) algorithm of wavelet transform, a related model for data mining and processing of children's intestinal ultrasound images and stool specimens was constructed. Then, the norovirus infection trend was warned based on the wavelet analysis algorithm model. The results showed that the intestinal ultrasound image processed by the wavelet transform algorithm was clearer. The positive detection rate of norovirus in children with clinical diarrhea was as high as 59%, and the children had different degrees of body damage, of which the probability of compensatory metabolic acidosis was the highest. The epidemiological analysis found that children with norovirus infection were mainly concentrated in the age group under 2 years old and over 5 years old and showed a peak of infection in December. In summary, the intelligent algorithm based on wavelet transform can realize the noise reduction of intestinal ultrasound, and it should protect children with susceptible age and susceptible seasons to reduce the clinical infection rate of norovirus.

Clinical evaluation of a wearable sensor for mobile monitoring of respiratory rate on hospital wards

A wireless and wearable system was recently developed for mobile monitoring of respiratory rate (RR). The present study was designed to compare RR mobile measurements with reference capnographic measurements on a medical-surgical ward. The wearable sensor measures impedance variations of the chest from two thoracic and one abdominal electrode. Simultaneous measurements of RR from the wearable sensor and from the capnographic sensor (1 measure/minute) were compared in 36 ward patients. Patients were monitored for a period of 182 ± 56 min (range 68–331). Artifact-free RR measurements were available 81% of the monitoring time for capnography and 92% for the wearable monitoring system (p < 0.001). A total of 4836 pairs of simultaneous measurements were available for analysis. The average reference RR was 19 ± 5 breaths/min (range 6–36). The average difference between the wearable and capnography RR measurements was − 0.6 ± 2.5 breaths/min. Error grid analysis showed that the proportions of RR measurements done with the wearable system were 89.7% in zone A (no risk), 9.6% in zone B (low risk) and < 1% in zones C, D and E (moderate, significant and dangerous risk). The wearable method detected RR values > 20 (tachypnea) with a sensitivity of 81% and a specificity of 93%. In ward patients, the wearable sensor enabled accurate and precise measurements of RR within a relatively broad range (6–36 b/min) and the detection of tachypnea with high sensitivity and specificity.

Tapentadol versus oxycodone analgesia and side effects after laparoscopic hysterectomy: A randomised controlled trial

BACKGROUND

Tapentadol is an opioid, which acts as a μ-opioid receptor agonist and inhibits noradrenaline reuptake in the central nervous system. This dual mechanism of action results in synergistic analgesic effects and potentially less side effects. This has been shown in treatment of chronic pain but postoperative studies are sparse.

OBJECTIVES

The main aim was to compare the analgesic effect of tapentadol with oxycodone after laparoscopic hysterectomy. Opioid side effects were recorded as secondary outcomes.

DESIGN

Randomised, blinded trial.

SETTING

Single-centre, Oslo University Hospital, Norway, December 2017 to February 2019.

PATIENTS

Eighty-six opioid-naïve American Society of Anesthesiologists physical status 1 to 3 women undergoing laparoscopic hysterectomy for nonmalignant conditions.

INTERVENTION

The patients received either oral tapentadol (group T) or oxycodone (group O) as part of multimodal pain treatment. Extended-release study medicine was administered 1 h preoperatively and after 12 h. Immediate-release study medicine was used as rescue analgesia.

MAIN OUTCOME MEASURES

Pain scores, opioid consumption and opioid-induced side effects were evaluated during the first 24 h after surgery.

RESULTS

The groups scored similarly for pain at rest using a numerical rating scale (NRS) 1 h postoperatively (group T 4.4, 95% CI, 3.8 to 5.0, group O 4.6, 95% CI, 3.8 to 5.3). No statistically significant differences were found between the groups for NRS at rest or while coughing during the 24-h follow-up period (P = 0.857 and P = 0.973). Mean dose of oral rescue medicine was similar for the groups (P = 0.914). Group T had significantly lower odds for nausea at 2 and 3 h postoperatively (P = 0.040, P = 0.020) and less need for antiemetics than group O. No differences were found for respiratory depression, vomiting, dizziness, pruritus, headache or sedation.

CONCLUSION

We found tapentadol to be similar in analgesic efficacy to oxycodone during the first 24 h after hysterectomy, but with significantly less nausea.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03314792.

Patient monitoring in the nonoperating room anesthesia (NORA) setting: current advances in technology

PURPOSE OF REVIEW

Nonoperating room anesthesia (NORA) procedures continue to increase in type and complexity as procedural medicine makes technical advances. Patients presenting for NORA procedures are also older and sicker than ever. Commensurate with the requirements of procedural medicine, anesthetic monitoring must meet the American Society of Anesthesiologists standards for basic monitoring.

RECENT FINDINGS

There have been improvements in the required monitors that are used for intraoperative patient care. Some of these changes have been with new technologies and others have occurred with software refinements. In addition, specialized monitoring devises have also been introduced into NORA locations (depth of hypnosis, respiratory monitoring, point-of care ultrasound). These additions to the monitoring tools available to the anesthesiologist working in the NORA-environment push the boundaries of procedures which may be accomplished in this setting.

SUMMARY

NORA procedures constitute a growing percentage of total administered anesthetics. There is no difference in the monitoring standard between that of an anesthetic administered in an operating room and a NORA location. Anesthesiologists in the NORA setting must have the same compendium of monitors available as do their colleagues working in the operating suite.

Ventilation Monitoring

Ventilation or breathing is vital for life yet is not well monitored in hospital or at home. Respiratory rate is a neglected vital sign and tidal volumes together with breath sounds are checked infrequently in many patients. Medications with the potential to depress ventilation are frequently administered, and may be accentuated by obesity causing airway obstruction in the form of sleep apnea. Sepsis may adversely affect ventilation by causing an increase in respiratory rate, often a very early sign of infection. Changes in ventilation may be early signs of deterioration in the patient.

Large difference between Enghoff and Bohr dead space in ventilated infants with hypoxemic respiratory failure

BACKGROUND

Ventilated neonates with hypoxemic respiratory failure (HRF) may show a ventilation-perfusion (V/Q) mismatch.

OBJECTIVE

To evaluate the difference between the Bohr (V_{d, Bohr} ) and Enghoff (V_{d, Enghoff} ) dead spaces in infants by using volumetric capnography based on ventilator graphics and capnograms.

METHODS

This study enrolled 46 ventilated infants (mean birth weight, 2239 ± 640 g; mean gestational age, 35.5 ± 3.3 weeks). We performed volumetric capnography and calculated V_{d, Bohr} and V_{d, Enghoff} when arterial blood sampling was necessary for treatment. According to the oxygenation index (OI) based on the Montreux definition of neonatal acute respiratory distress syndrome, each measurement was classified into the HRF (OI ≥ 4) or control (OI < 4) group. Then, a regression analysis was performed to evaluate the correlation between the OI and the difference between V_{d, Enghoff} and V_{d, Bohr} .

RESULTS

The median V_{d, Enghoff} /tidal volume (V_T ) was significantly higher in the HRF group (0.55 [interquartile range, 0.47-0.68]) than in the control group (0.46 [0.37-0.57]). The HRF group showed a larger difference between V_{d, Enghoff} /V_T and V_{d, Bohr} /V_T than the control group (median, 0.22 [0.15-0.29] vs. 0.10 [0.06-0.14], respectively). Moreover, the regression analysis of the relationship between OI and V_{d, Enghoff} /V_T  - V_{d, Bohr} /V_T showed a positive correlation (r = .60, p < .001).

CONCLUSION

Ventilated neonates with hypoxemic respiratory failure showed a large difference between V_{d, Enghoff} and V_{d, Bohr} , possibly reflecting a low V/Q mismatch and right-to-left shunting.

Modeling the Cost Savings of Continuous Pulse Oximetry and Capnography Monitoring of United States General Care Floor Patients Receiving Opioids Based on the PRODIGY Trial

INTRODUCTION

Despite the high incidence of respiratory depression on the general care floor and evidence that continuous monitoring improves patient outcomes, the cost-benefit of continuous pulse oximetry and capnography monitoring of general care floor patients remains unknown. This study modeled the cost and length of stay savings, investment break-even point, and likelihood of cost savings for continuous pulse oximetry and capnography monitoring of general care floor patients at risk for respiratory depression.

METHODS

A decision tree model was created to compare intermittent pulse oximetry versus continuous pulse oximetry and capnography monitoring. The model utilized costs and outcomes from the PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY (PRODIGY) trial, and was applied to a modeled cohort of 2447 patients receiving opioids per median-sized United States general care floor annually.

RESULTS

Continuous pulse oximetry and capnography monitoring of high-risk patients is projected to reduce annual hospital cost by $535,531 and cumulative patient length of stay by 103 days. A 1.5% reduction in respiratory depression would achieve a break-even investment point and justify the investment cost. The probability of cost saving is ≥ 80% if respiratory depression is decreased by ≥ 17%. Expansion of continuous monitoring to high- and intermediate-risk patients, or to all patients, is projected to reach a break-even point when respiratory depression is reduced by 2.5% and 3.5%, respectively, with a ≥ 80% probability of cost savings when respiratory depression decreases by ≥ 27% and ≥ 31%, respectively.

CONCLUSION

Compared to intermittent pulse oximetry, continuous pulse oximetry and capnography monitoring of general care floor patients receiving opioids has a high chance of being cost-effective.

TRIAL REGISTRATION

www.clinicaltrials.gov , Registration ID: NCT02811302.

Evaluation of Noninvasive Respiratory Volume Monitoring in the PACU of a Low Resource Kenyan Hospital

This research aims to evaluate the use of the noninvasive respiratory volume monitor (RVM) compared to the standard of care (SOC) in the Post-Anesthesia Care Unit (PACU) of Kijabe Hospital, Kenya. The RVM provides real-time measurements for quantitative monitoring of non-intubated patients. Our evaluation was focused on the incidence of postoperative opioid-induced respiratory depression (OIRD). The RVM cohort (N = 50) received quantitative OIRD assessment via the RVM, which included respiratory rate, minute ventilation, and tidal volume. The SOC cohort (N = 46) received qualitative OIRD assessment via patient monitoring with oxygenation measurements (SpO₂) and physical examination. All diagnosed cases of OIRD were in the RVM cohort (9/50). In the RVM cohort, participants stayed longer in the PACU and required more frequent airway maneuvers and supplemental oxygen, compared to SOC (all p < 0.05). The SOC cohort may have had fewer diagnoses of OIRD due to the challenging task of distinguishing hypoventilation versus OIRD in the absence of quantitative data. To account for the higher OIRD risk with general anesthesia (GA), a subgroup analysis was performed for only participants who underwent GA, which showed similar results. The use of RVM for respiratory monitoring of OIRD may allow for more proactive care.

Perioperative Management of the Patient With Obstructive Sleep Apnea: A Narrative Review

The prevalence of obstructive sleep apnea (OSA) has reached 1 billion people worldwide, implying significant risk for the perioperative setting as patients are vulnerable to cardiopulmonary complications, critical care requirement, and unexpected death. This review summarizes main aspects and considerations for the perioperative management of OSA, a condition of public health concern. Critical determinants of perioperative risk include OSA-related changes in upper airway anatomy with augmented collapsibility, diminished capability of upper airway dilator muscles to respond to airway obstruction, disparities in hypoxemia and hypercarbia arousal thresholds, and instability of ventilatory control. Preoperative OSA screening to identify patients at increased risk has therefore been implemented in many institutions. Experts recommend that in the absence of severe symptoms or additional compounding health risks, patients may nevertheless proceed to surgery, while heightened awareness and the adjustment of postoperative care is required. Perioperative caregivers should anticipate difficult airway management in OSA and be prepared for airway complications. Anesthetic and sedative drug agents worsen upper airway collapsibility and depress central respiratory activity, while the risk for postoperative respiratory compromise is further increased with the utilization of neuromuscular blockade. Consistently, opioid analgesia has proven to be complex in OSA, as patients are particularly prone to opioid-induced respiratory depression. Moreover, basic features of OSA, including intermittent hypoxemia and repetitive sleep fragmentation, gradually precipitate a higher sensitivity to opioid analgesic potency along with an increased perception of pain. Hence, regional anesthesia by blockade of neural pathways directly at the site of surgical trauma as well as multimodal analgesia by facilitating additive and synergistic analgesic effects are both strongly supported in the literature as interventions that may reduce perioperative complication risk. Health care institutions are increasingly allocating resources, including those of postoperative enhanced monitoring, in an effort to increase patient safety. The implementation of evidence-based perioperative management strategies is however burdened by the rising prevalence of OSA, the large heterogeneity in disease severity, and the lack of evidence on the efficacy of costly perioperative measures. Screening and monitoring algorithms, as well as reliable risk predictors, are urgently needed to identify OSA patients that are truly in need of extended postoperative surveillance and care. The perioperative community is therefore challenged to develop feasible pathways and measures that can confer increased patient safety and prevent complications in patients with OSA.

Perioperative adherence to continuous positive airway pressure and its effect on postoperative nocturnal hypoxemia in obstructive sleep apnea patients: a prospective cohort study

Background

Although continuous positive airway pressure (CPAP) is the first line treatment for obstructive sleep apnea (OSA) patients, the perioperative adherence rate is unclear. The objective of this study was to determine the perioperative adherence rate of patients with OSA with a CPAP prescription and the effect of adherence on nocturnal oxygen saturation.

Methods

This prospective cohort study included adult surgical patients with a diagnosis of OSA with CPAP prescription undergoing elective non-cardiac surgery. Patients were divided into CPAP adherent and non-adherent groups based on duration of usage (≥ 4 h/night). Overnight oximetry was performed preoperatively and on postoperative night 1 and 2 (N1, N2). The primary outcome was adherence rate and the secondary outcome was nocturnal oxygen saturation.

Results

One hundred and thirty-two patients completed the study. CPAP adherence was 61% preoperatively, 58% on postoperative N1, and 59% on N2. Forty-nine percent were consistently CPAP adherent pre- and postoperatively. Using a linear fixed effects regression, oxygen desaturation index (ODI) was significantly improved by CPAP adherence (p = 0.0011). The interaction term CPAP x N1 was significant (p = 0.0015), suggesting that the effect of CPAP adherence varied on N1 vs preoperatively. There was no benefit of CPAP adherence on postoperative mean SpO₂, minimum SpO₂, and percentage of sleep duration with SpO₂ < 90%. Use of supplemental oxygen therapy was much lower in the CPAP adherent group vs non-adherent group (9.8% vs 46.5%, p <  0.001).

Conclusions

Among patients with a preoperative CPAP prescription, approximately 50% were consistently adherent. CPAP adherence was associated with improved preoperative ODI and the benefit was maintained on N1. These modest effects may be underestimated by a higher severity of OSA in the CPAP adherent group and a higher rate of oxygen supplementation in the non-adherent group.

Trial registration

ClinicalTrials.Gov registry (NCT02796846).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01371-0.