Capnography Monitoring Research Articles

Quantifying neurovascular coupling through a concurrent assessment of arterial, capillary, and neuronal activation in humans: A multimodal EEG-fNIRS-TCD investigation

BackgroundThis study explored a novel multimodal neuroimaging approach to assess neurovascular coupling (NVC) in humans using electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and transcranial Doppler ultrasound (TCD). MethodsFifteen participants (nine females; age 19–32) completed concurrent EEG-fNIRS-TCD imaging during motor (finger tapping) and visual (“Where's Waldo?”) tasks, with synchronized monitoring of blood pressure, capnography, and heart rate. fNIRS assessed microvascular oxygenation within the frontal, motor, parietal, and occipital cortices, while the middle and posterior cerebral arteries (MCA/PCA) were insonated using TCD. A 16-channel EEG set-up was placed according to the 10–20 system. Wilcoxon signed-rank tests were used to compare physiological responses between the active and resting phases of the tasks, while cross-correlations with zero legs compared cerebral and systemic hemodynamic responses across both tasks. ResultsTime-frequency analysis demonstrated a reduction in alpha and low beta band power in electrodes C3/C4 during finger tapping (p<0.045) and all electrodes during the Waldo task (all p<0.001). During Waldo, cross-correlation analysis demonstrated the change in oxygenated hemoglobin and cerebral blood velocity had a moderate-to-strong negative correlation with systemic physiological influences, highlighting the measured change resulted from neuronal input. Deoxygenated hemoglobin displayed the greatest negative cross-correlation with the MCA/PCA within the motor cortices and visual during the motor and visual tasks, respectively (range:0.54, -0.82). ConclusionsThis investigation demonstrated the feasibility of the proposed EEG-fNIRS-TCD response to comprehensively assess the NVC response within human, specifically quantifying the real-time temporal synchrony between neuronal activation (EEG), microvascular oxygenation changes (fNIRS), and conduit artery velocity alterations (TCD).

Continuous Capnography for Early Detection of Respiratory Compromise During Gastroenterological Procedural Sedation and Analgesia.

Gastroenterology nurses working across a variety of clinical settings are responsible for periprocedural monitoring during moderate to deep procedural sedation and analgesia (PSA) to identify signs of respiratory compromise and intervene to prevent cardiorespiratory events. Pulse oximetry is the standard of care for respiratory monitoring, but it may delay or fail to detect abnormal ventilation during PSA. Continuous capnography, which measures end-tidal CO2 as a marker of alveolar ventilation, has been endorsed by a number of clinical guidelines. Large clinical trials have demonstrated that the addition of continuous capnography to pulse oximetry during PSA for various gastroenterological procedures reduces the incidence of hypoxemia, severe hypoxemia, and apnea. Studies have shown that the cost of adding continuous capnography is offset by the reduction in adverse events and hospital length of stay. In the postanesthesia care unit, continuous capnography is being evaluated for monitoring opioid-induced respiratory depression and to guide artificial airway removal. Studies are also examining the utility of continuous capnography to predict the risk of opioid-induced respiratory depression among patients receiving opioids for primary analgesia. Continuous capnography monitoring has become an essential tool to detect early signs of respiratory compromise in patients receiving PSA during gastroenterological procedures. When combined with pulse oximetry, it can help reduce cardiorespiratory adverse events, improve patient outcomes and safety, and reduce health care costs.

Integrated pulmonary index during procedural sedation and analgesia: A cluster-randomized trial.

To evaluate the effectiveness of utilizing the integrated pulmonary index for capnography implementation during sedation administered by nurses. Cluster-randomized trial. Participants were enrolled from the interventional radiology department at an academic hospital in Canada. Nurses were randomized to either enable or disable the Integrated Pulmonary Index feature of the capnography monitor. Procedures were observed by a research assistant to collect information about alarm performance characteristics. The primary outcome was the number of seconds in an alert condition state without an intervention being applied. The number of seconds in an alarm state without intervention was higher in the group that enabled the integrated pulmonary index compared to the group that disabled this feature, but this difference did not reach statistical significance. Likewise, the difference between groups for the total alarm duration, total number of alarms and the total number of appropriate alarms was not statistically significant. The number of inappropriate alarms was higher in the group that enabled the Integrated Pulmonary Index, but this estimate was highly imprecise. There was no difference in the odds of an adverse event (measured by the Tracking and Reporting Outcomes of Procedural Sedation tool) occurring between groups. Desaturation events were uncommon and brief in both groups but the area under the SpO2 90% desaturation curve scores were lower for the group that enabled the integrated pulmonary index. Enabling the integrated pulmonary index during nurse-administered procedural sedation did not reduce nurses' response times to alarms. Therefore, integrating multiple physiological parameters related to respiratory assessment into a single index did not lower the threshold for intervention by nurses. The time it takes to respond to capnography monitor alarms will not be reduced if the integrated pulmonary Iindex feature of capnography monitors is enabled during nurse-administered procedural sedation. Results do not support the routine enabling of the integrated pulmonary index when nurses use capnography to monitor patients during procedural sedation as a strategy to reduce the time it takes to initiate responses to alarms. CONSORT. There was no patient or public contribution. This study was prospectively registered at ClinicalTrials.gov (ID: NCT05068700).

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

PurposeThis 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. DesignA 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. MethodsPreimplementation 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. FindingsAge, 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). ConclusionsPatients 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.

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.

Monitoring of physiologic features and treatment aspects of children on home invasive mechanical ventilation.

Pediatric home invasive mechanical ventilation patients are a small but resource-intensive cohort, requiring close monitoring and multidisciplinary care. Patients are often dependent on their ventilator for life support, with any significant complications such as equipment failure, tracheostomy blockage, or accidental decannulation becoming potentially life-threatening if not identified quickly. This review discusses the indications and variations in practice worldwide, in terms of models of care, including home care provision, choice of equipment, and monitoring. With advances in technology, optimal monitoring strategies for home, continue to be debated: In-built ventilator alarms are often inadequately sensitive for pediatric patients, necessitating additional external monitoring devices to minimize risk. Pulse oximetry has been the preferred monitoring modality at home, though in some special circumstances such as congenital central hypoventilation syndrome, home carbon dioxide monitoring may be important to consider. Children should be under regular follow-up at specialist respiratory centers where clinical evaluation, nocturnal oximetry, and capnography monitoring and/or poly(somno)graphy and analysis of ventilator download data can be performed regularly to monitor progress. Recent exciting advances in technology, particularly in telemonitoring, which have potential to hugely benefit this complex group of patients are also discussed.

Procedural sedation of adult patients in the emergency department: a best practice implementation project.

The emergency department is a fast-paced and complex health care setting, where critical care is provided to patients of all ages. However, various environmental factors, such as high patient volumes, overburdened staff, and frequent nurse turnover, can hinder the use of evidence-based practices during procedural sedation. Proper patient monitoring is essential to prevent adverse events during procedural sedation. The goal of this implementation project was to enhance compliance with best practices for patient monitoring during procedural sedation in the emergency department. The project used the JBI Model of Evidence-Based Healthcare and JBI's Getting Research into Practice (GRiP) tool for implementing evidence-based monitoring practices for adult patients during procedural sedation in the emergency department. A baseline audit was conducted to assess current practice against evidence-based recommendations, followed by the implementation of strategies to improve compliance with best practices. The project concluded with a follow-up audit to determine any improvement in practice. The baseline audit revealed 81% overall compliance with evidence-based practice. Three barriers were identified, namely, lack of staff education, increased turnover rate of nurses, and the need for nurses to be mobile during procedural sedation. Strategies were implemented to improve compliance with evidence-based practice. The follow-up audit showed an overall improvement of 95% after project implementation. The project improved best practices for patient monitoring during procedural sedation in the emergency department. However, more work remains to be done to ensure the sustainability of the best practices, including monitoring of end-tidal capnography and vital sign assessment.

Lung tissue injury and hemodynamic effects of ventilations synchronized or unsynchronized to continuous chest compressions in a porcine cardiac arrest model

AimCompare lung injury and hemodynamic effects in synchronized ventilations (between two chest compressions) vs. unsynchronized ventilations during cardiopulmonary resuscitation (CPR) in a porcine model of cardiac arrest. MethodsTwenty pigs were randomized to either synchronized or unsynchronized group. Ventricular fibrillation was induced electrically and left for 1.5 minutes. Four minutes of basic chest compression:ventilation (30:2) CPR was followed by eight minutes of either synchronized or unsynchronized ventilations (10/min) during continuous compressions before defibrillation was attempted. Aortic, right atrial and intracerebral pressures, carotid and cerebral blood flow and cardiac output were measured. Airway monitoring included capnography and respiratory function monitor. Macro- and microscopic lung injuries were assessed post-mortem. ResultsThere were no significant differences between groups in any of the measured hemodynamic variables or inspiration time (0.4 vs. 1.0 s, p = 0.05). The synchronized ventilation group had lower median peak inspiratory airway pressure (57 vs. 94 cm H2O, p < 0.001), lower minute ventilation (3.7 vs. 9.4 l min−1, p < 0.001), lower pH (7.31 vs. 7.53, p < 0.001), higher pCO2 (5.2 vs. 2.5 kPa, p < 0.001) and lower pO2 (31.6 vs. 54.7 kPa, p < 0.001) compared to the unsynchronized group after 12 minutes of CPR. There was significant lung injury after CPR in both synchronized and unsynchronized groups. ConclusionSynchronized and unsynchronized ventilations resulted in similar hemodynamics and lung injury during continuous mechanical compressions of pigs in cardiac arrest. Animals that received unsynchronized ventilations with one second inspiration time at a rate of ten ventilations per minute were hyperventilated and hyperoxygenated.Institutional protocol number: FOTS, id 6948.

Safety standards in anesthesiology and during regional anesthesia: implementation in Ukraine

Patient safety in surgical settings is an integral part of the further sustainable development of medicine in Ukraine. This is key in times of the war and post-war state when the budget deficit at all levels of public administration and health care is significant and may grow significantly in the future. Medical errors during anesthetic management and surgery are particularly costly and significantly burden the health care system. Even the wealthiest economies cannot afford such mistakes. The price is particularly high for Ukrainian realities, and these mistakes are fatal for our health care. For this review, the authors used the electronic databases MEDLINE and Embase. 15 studies were included in the review. A part of the data was also included from the department research. Demonstration of own results is limited, as the data have already been published in other publications or materials are in the reviewing process. Basic monitoring according to the WHO standards / World Federation of Societies of Anesthesiologists (WFSA) is mainly used in hospitals of European Union countries. Results are close to 100 % for pulseoximetry and blood pressure, 98 % for electrocardiography, and 96 % for capnography. In Ukraine, monitoring methods do not have critical differences, except for a slightly lower (73.7 %) spread of capnography and ECG monitoring (83.4 %). The situation is less encouraging in the context of regional anesthesia. In Ukraine, the situation is much worse. According to the survey conducted by our department, ultrasound navigation is available in only 67 % of hospitals. There is also a low level of taking safety measures, which include checklists, training, and clinical analyzes of errors. Conclusions. According to the data of this literature review, the components of the Declaration of Helsinki on safety in anesthesiology are gradually being implemented in Ukraine, the use of the WHO checklist “Safe surgery” and safety standards of regional anesthesia is spreading. The main directions for further development are the education of physicians and other staff on patient safety, the approval of national standards and monitoring of their implementation in practice, the creation of a notification and audit system for complications and critical incidents during anesthesia.

Value of integrated pulmonary index monitoring for the detection of adverse respiratory events in patients undergoing sedation for gastrointestinal system endoscopy.

To determine if the integrated pulmonary index detects changes in ventilation status early in patients undergoing gastrointestinal endoscopy under sedation, and to determine the risk factors affecting hypoxia. The retrospective study was conducted at the endoscopy unit of a tertiary university hospital in Turkey and comprised data between October 2018 and December 2019 related to patients of either gender aged >18 years who were assessed as American Society of Anaesthesiologists grade I-III and underwent elective lower and upper gastrointestinal endoscopy. Monitoring was done with capnography in addition to standard procedures. Data was analysed using SPSS 23. Of the 154 patients, 94(%) were females and 60(%) were males. The overall mean age was 50.88±11.8 years (range: 20-70 years). Mean time under anaesthesia was 23.58±4.91 minutes and mean endoscopy time was 21.73±5.06 minutes. During the procedure, hypoxia was observed in 42(27.3%) patients, severe hypoxia in 23(14.9%) and apnoea in 70(45.5%). Mean time between apnoea and hypoxia was 12.59±7.99 seconds, between apnoea and serious hypoxia 21.07±17.64 seconds, between integrated pulmonary index score 1 and hypoxia 12.91±8.17 sec, between integrated pulmonary index score 1 and serious hypoxia 21.59±14.13 seconds, between integrated pulmonary index score <7 and hypoxia 19.63±8.89 seconds, between integrated pulmonary index score <7 and serious hypoxia 28.39±12.66 seconds, between end-tidal carbon dioxide and hypoxia 12.95±8.33 seconds, and between end-tidal carbon dioxide and serious hypoxia 21.29±7.55 seconds. With integrated pulmonary index score 1, sensitivity value for predicting hypoxia and severe hypoxia was 88.1% and 95.7%, respectively, and specificity was 67% and 60.3%, respectively. With integrated pulmonary index score <7, the corresponding values were 100%, 100%, 42% and 64.1%, respectively. Capnographic monitoring, especially the follow-up integrated pulmonary index score, was found to be valuable and reliable in terms of finding both time and accuracy of the risk factor in the diagnosis of respiratory events.

Abstract 185: Regional Oxygen Saturation and Capnography Monitoring During Resuscitation After Cardiac Arrest in a Swine Pediatric ARDS Model

Introduction: Survival and outcomes after cardiac arrest (CA) depend largely on the effectiveness of cardiopulmonary resuscitation (CPR). Traditional invasive methods of monitoring CPR can be challenging out-of-hospital and are lacking in more than 50% of in-hospital pediatric CA. Regional oxygen saturation (rSO 2 ) monitoring with Near Infrared Spectroscopy (NIRS) and volumetric capnography offers a noninvasive approach that could potentially overcome these challenges. Aim: To determine the feasibility and effectiveness of NIRS and volumetric capnography monitoring in a swine model of pediatric hypoxia induced CA. Approach: Juvenile pigs were sedated and mechanically ventilated. Mild to moderate Acute Respiratory Distress Syndrome (ARDS) was induced by continuous oleic acid infusion. Respiratory and hemodynamic variables were monitored using invasive and noninvasive (NIRS and capnography) monitoring to assess efficacy of CPR. Animals were randomized into one of the two groups: High-quality CPR (hqCPR) to achieve coronary perfusion pressure of 25-30 mmHg and low-quality CPR (lqCPR) to achieve coronary perfusion pressure of 10-15 mmHg. Trajectories over time were analyzed using regression analyses. The discriminatory ability to distinguish between groups based on trajectories were analyzed using receiver operating characteristics curve (ROC) analysis. Results: 39 animals (23±3 kg) were included in our study. In the hqCPR group, there are generally higher values for cerebral and renal rSO 2 , ETCO 2 , volume of CO 2 elimination (VCO 2 ), and carotid blood flow, compared to the lqCPR group (p&lt;0.0001). Cerebral and renal rSO 2 values increase over time, while ETCO 2 , VCO 2 , and carotid flow values decrease in the hqCPR group. Cerebral rSO2 had a ROC AUC of 0.76 (95% CI: 0.58-0.94), whereas renal rSO2 had a ROC AUC of 0.54 (95% CI: 0.22-0.87) representing nearly no discrimination ability. ETCO 2 had a ROC AUC of 0.66 (95% CI: 0.49-0.84), whereas VCO 2 had a ROC AUC of 0.62 (95% CI: 0.38-0.85). Conclusions: Higher mean cerebral rSO2 values during CPR might be used to assess quality of CPR effectiveness and provide real-time adjustments as needed. This could guide healthcare providers in optimizing CPR quality and improving outcomes for cardiac arrest patients.

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

BackgroundSupplemental 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.MethodsThis 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.ResultsWithin 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).ConclusionsDespite 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 registrationClinicaltrials.gov: NCT02811302, registered June 23, 2016.

Patient Safety during Propofol Sedation before and after Implementation of Capnography Monitoring.

Endoscopic procedures are routinely applied to cancer screening programs and surveillance. The preferred technique is usually deep sedation with propofol being a convenient agent allowing for a quicker patient recovery while maintaining a similar safety profile compared to traditional agents. However, adverse events, including respiratory depression and consequent undesirable cardiovascular side effects, may occur. The goal of this work is to evaluate the patient safety impact of adding capnography during endoscopic procedures under deep propofol sedation. Data were retrospectively collected from patients undergoing deep, procedural sedation for gastrointestinal (GI) endoscopy in October 2019 to January 2021 in a single Turkish university hospital. Included in the analysis were all adult patients classified by the American Society of Anesthesiologists (ASA) as I-IV, who were scheduled for GI endoscopy utilizing propofol alone or in combination. Data on 1840 patients were collected, of whom 1610 (730 pre- and 880 post-capnography implemention) met inclusion criteria. The primary outcome was a change in the composite incidence of mild oxygen desaturation (SpO2 75-90% for <60 s), severe oxygen desaturation (SpO2 < 75% anytime or <90% for >60 s), bradycardia (<60 ppm), and tachycardia (>25% from baseline). Without capnography, on average, 7.5 events of the primary endpoint were observed per 100 procedures and 2.9 with additional capnography monitoring (p < 0.001). A significant reduction was observed for mild oxygen desaturation, with a resulting odds ratio of 0.25 (95% CI 0.14 to 0.46). ASA I patients had the highest difference in combined incidence of any oxygen desaturation of 5.85% in the pre-capnography group and 0.64% in the post-capnography group. Although procedural sedation using propofol is not associated with severe adverse events, the incidence of composite adverse events could be reduced with the addition of capnography monitoring.

Identifying Early Opioid-Induced Respiratory Depression and Rapid Response Team Activation

BackgroundOpioids can cause respiratory depression, which could lead to patient harm. The project site noted a gap in identifying and monitoring postsurgical thoracic patients at risk for opioid-induced respiratory depression (OIRD), so an evidence-based solution was sought. AimsThe purpose of this quality improvement project was to determine if translating the research by Khanna et al. (2020) on implementing the prediction of opioid-induced respiratory depression in patients monitored by capnography (PRODIGY) risk prediction tool would affect rapid response team (RRT) activation among postsurgical thoracic patients in a cardiovascular and thoracic care unit (CVTCU) at John Muir Medical Center, Concord Campus over four weeks. MethodsThe four-week quantitative quasi-experimental project had a total sample size of 29 participants. Pulse oximetry was used to identify OIRD in the comparison group (n = 12). The implementation group consisted of patients identified as at-risk for OIRD by the PRODIGY risk prediction tool and were monitored with pulse oximetry and capnography (n = 17). ResultsA χ2 analysis showed χ2 (1, n = 29) = .73, p = .393 for activation of the RRT using the PRODIGY risk prediction tool, which was not statistically significant. However, clinical significance was supported by a 5.9% increase in RRT activations. ConclusionBased on the results, implementing the PRODIGY risk prediction tool and capnography monitoring on at-risk patients may affect RRT activation in this population.

SAMAY S24: a novel wireless 'online' device for real-time monitoring and analysis of volumetric capnography.

Volumetric capnography (VCap) provides information about CO2 exhaled per breath (VCO2br) and physiologic dead space (VDphys). A novel wireless device with a high response time CO2 mainstream sensor coupled with a digital flowmeter was designed to monitor all VCap parameters online in rabbits (SAMAY S24).Ten New Zealand rabbits were anesthetized and mechanically ventilated. VCO2br corresponds to the area under the VCap curve. We used the modified Langley method to assess the airway VD (VDaw) and the alveolar CO2 pressure. VDphys was estimated using Bohr's formula, and the alveolar VD was calculated by subtracting VDaw from VDphys. We compared (Bland-Altman) the critical VCap parameters obtained by SAMAY S24 (Langley) with the Functional Approximation based on the Levenberg-Marquardt Algorithm (FA-LMA) approach during closed and opened chest conditions.SAMAY S24 could assess dead space volumes and VCap shape in real time with similar accuracy and precision compared to the 'offline' FA-LMA approach. The opened chest condition impaired CO2 kinetics, decreasing the phase II slope, which was correlated with the volume of CO2 exhaled per minute.

Capnographic monitoring reduces hypoxia incidence in older patients undergoing gastrointestinal endoscopy under propofol sedation: study protocol for a multicenter randomized controlled trial

BackgroundHypoxia is a very common adverse event that occurs during gastrointestinal endoscopy under sedation, especially in older patients, owing to limited reservation of heart, brain, lung, and other organs. Prolonged or severe hypoxia can cause ischemia of the coronary artery and permanent nervous system damage, and even result in death. Hence, it is imperative to reduce or prevent hypoxia during gastrointestinal endoscopy under sedation in older patients. Although several oxygen delivery methods would reduce hypoxia during this procedure, early detection of respiratory depression and early administration of intervention would be the best method to reduce or even confirm the hypoxia. Capnographic monitoring is reportedly more sensitive for detecting respiratory depression before the onset of hypoxia than the current clinical routine monitoring of pulse oxygen saturation; however, its effect is controversial. Therefore, in this study, we aimed to improve the safety of gastrointestinal endoscopy under sedation in older patients.MethodsA multicenter, randomized, single-blind, two-arm parallel-group, controlled with an active comparator, interventional superiority clinical trial will be conducted to evaluate the impact of an additional capnographic monitoring-based intervention on the incidence of hypoxia in older patients. Patients (n = 1800) scheduled for gastrointestinal endoscopy with propofol sedation will be randomly assigned to either a control or interventional arm, wherein standard or capnographic monitoring is implemented, respectively.DiscussionThis study primarily aims to examine whether an additional capnographic monitoring-based intervention can reduce the incidence of hypoxia in older patients during gastrointestinal endoscopy under propofol and sufentanil sedation. The results of this study may extensively impact gastrointestinal endoscopy under sedation and the development of associated guidelines.Trial registrationClinicalTrials.gov NCT05030870. Registered on September 1, 2021.

Preventing unrecognised oesophageal intubation.

Major harm from unrecognised oesophageal intubation continues, despite the 2018 Royal College of Anaesthetists' 'no trace, wrong place' campaign. It is likely that publicly reported cases represent a fraction of real occurrences. This article summarises a 2022 consensus guideline on the prevention of unrecognised oesophageal intubation from the Project for Universal Management of Airway and international airway societies. The guideline is written for all airway operators and assistants, in any clinical setting, and readers are advised to deepen their understanding by studying the original guideline. The recommendations include how to avoid and recognise oesophageal intubation as well as a set of logical actions to take when it is a plausible possibility, even if it is not suspected. The guideline emphasises the importance of videolaryngoscopy, capnography and oxygen saturation monitoring for all tracheal intubations, wherever performed. It introduces the concept of sustained exhaled carbon dioxide, which is central to identifying oesophageal intubation, and acting to prevent progression to unrecognised oesophageal intubation. In the absence of sustained exhaled carbon dioxide, the default action is to remove the tube. This will mean some tracheal placed tubes are removed but based on a risk-benefit analysis, this is desirable. The tube should only be left in place if there is clear danger in removing it and in this event, its position should be confirmed, using repeat videolaryngoscopy plus one other of bronchoscopy, skilled ultrasound or use of an oesophageal detector device. The importance of human factors is underlined; for instance, the value of a shared and vocalised report of videolaryngoscopy view and trained assistants working with the operator to confirm whether the criteria for sustained exhaled carbon dioxide are met, to minimise error and improve team working.

ROLE OF CAPNOGRAPHY IN SAFE SEDATION OF VITRECTOMY PATIENTS

Purpose: To evaluate the efficiency of the capnography monitoring added to routine monitoring on oxygen desaturation, hypoxemia, and other vital parameters. Methods: 100 adult patients who had elective vitrectomy under sedation were included in this study. Patients were divided into “experiment”(capnography added to routine monitoring) and “control”(capnography not added to routine monitoring) groups. Hypoxemia, desaturation, tachycardia, bradycardia, additional maneuvers for the airway were compared. Increase and decrease in end-tidal carbon dioxide (EtCO2) levels, hypoxemia, desaturation, Integrated Pulmonary Index (IPI) levels requiring attention (5-7), and intervention (1-4) were determined in the experiment group, and frequencies of them were assessed. Results: Desaturation and bradycardia rates and counts in the experiment group were significantly lower than the control group. No significant difference was seen between groups in terms of hypoxemia, tachycardia, and additional maneuvers. 76%(38/50) of experiment group patients had decrease in EtCO2, 10%(5/50) increase in EtCO2, 38%(19/50) apnea, 52%(26/50) IPI levels requiring attention, 14%(7/50) IPI levels requiring intervention. Conclusion: With addition of the capnography to routine monitoring of sedated vitrectomy patients, oxygen desaturation and bradycardia can be less likely to occur, and with instant follow-up of the EtCO2, apnea, and IPI levels; respiratory depression can be recognized before oxygen desaturation develops.

Implementing capnography monitoring in recovery units: barriers and solutions

Implementing capnography monitoring in recovery units: barriers and solutions

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

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