End-tidal Carbon Dioxide Monitoring Research Articles

Correlation between EtCO2 and PCO2 in patients undergoing critical care transport

ABSTRACT OBJECTIVES End-tidal carbon dioxide (EtCO2) monitoring is widely used as a surrogate for the partial pressure of carbon dioxide (PCO2) in critically ill patients receiving manual or mechanical ventilation in prehospital, emergency, and critical care settings. Specific targets for ETCO2 are a key component of Emergency Medical Services (EMS) protocols, especially for specific patient groups such as those with traumatic brain injury. However, the correlation between EtCO2 and venous or arterial PCO2 is uncertain. We aimed to assess the correlation between EtCO2 and PCO2 in intubated patients undergoing critical care transport (CCT), and in specific subgroups of patients. METHODS We performed a retrospective review of patients undergoing emergency transport by a multi-state CCT agency. Patients were included if they had an advanced airway and both an EtCO2 and PCO2 reading within 5 minutes of each other. We obtained data on patient demographics, transport characteristics, medical categories, vital signs, lab values, and specific interventions. We performed univariable and multivariable binary logistic regression to assess the association between delta PCO2 and these characteristics. RESULTS We included 6,459 patients (mean age 58.4 years [SD 18.5], 57.1% male), of which a subset of 551 patients had multiple EtCO2-PCO2 measurements within 5 minutes. The median (IQR) initial delta PCO2 was 12.9 mmHg (7.1, 21.9). 3,967 (61.4%) patients had a delta PCO2 >10 mmHg and 1,843 (28.5%) had a delta PCO2 >20 mmHg. We identified an independent association between delta PCO2 >10 mmHg and age, male sex, interfacility transport, venous sampling site, respiratory rate, hypotension, hypoxia, and thoracostomy. In patients with multiple blood gas measurements, 76% had delta PCO2 >10 mmHg over the duration of the transport. CONCLUSIONS We identified substantial differences between EtCO2 and PCO2 across patients with medical and traumatic conditions undergoing critical care transport. The PCO2 assessment should be strongly considered as part of ventilatory management in patients encountered in emergency and critical care settings.

Transcutaneous carbon dioxide monitoring in children undergoing rigid bronchoscopy: a prospective blinded observational study.

Anesthetic management during rigid bronchoscopy in children can be challenging, and continuous end-tidal carbon dioxide (EtCO2) monitoring is often unachievable. Transcutaneous carbon dioxide (TcCO2) monitoring is strongly correlated with the partial pressure of carbon dioxide (PaCO2) and EtCO2. We aimed to investigate the incidence of hypercapnia in children undergoing rigid bronchoscopy. We enrolled patients aged < 18yr scheduled for rigid bronchoscopy in a prospective observational study. We recorded TcCO2 values from anesthesia induction to the postanesthesia care unit (PACU) stay. We ended monitoring when TcCO2 reached values ≤ 50mm Hg. The operating room (OR) team was blinded to the TcCO2. The outcome of primary interest was the incidence of hypercapnia (TcCO2 > 50mm Hg) in the OR. Other outcomes were the incidences of hypercapnia in the PACU and severe hypercapnia (TcCO2 > 90mm Hg), factors possibly related to hypercapnia (patient, surgery, or anesthesia factors), and the incidence of perioperative adverse events. A total of 30 patients were enrolled. The median [interquartile range (IQR)] age was 3.5 [1.5-8.0] yr. The incidence of hypercapnia was 100% in the OR and 60% in the PACU. Five cases (17%) presented with severe hypercapnia in the OR. The highest median [IQR] TcCO2 was 69 [61-79] mm Hg. The most common adverse event was oxygen desaturation (57%, 17/30). Patients with severe hypercapnia had long stays in the PACU. Hypercapnia was a frequent event in children undergoing rigid bronchoscopy and severe hypercapnia was associated with a long PACU stay. Further studies are needed to assess the utility of TcCO2 monitoring in guiding ventilatory interventions during these cases.

Oesophageal intubations in anaesthetic practice across Australia and New Zealand: A webAIRS analysis of 109 incidents.

Oesophageal intubations are more common than may be realised and can potentially cause significant patient harm even if promptly identified and corrected. Reports of morbidity due to unrecognised oesophageal intubation continue to present in coroner and media reports. Therefore, it would be helpful to identify mechanisms to prevent these events and implement strategies to avoid and identify incorrect endotracheal tube placement. This analysis of oesophageal intubations reported to webAIRS aims to provide an in-depth analysis of all events in which oesophageal intubation occurred. WebAIRS is a web-based, bi-national incident reporting system collecting voluntarily reported anaesthetic events across Australia and New Zealand, with more than 10,500 incidents registered. A structured search through the webAIRS database identified 109 reports of oesophageal intubation reported between July 2009 and September 2022. A common cause of oesophageal intubation was the misidentification of the larynx due to a poor laryngeal view. Desaturation directly attributed to the misplaced endotracheal tube occurred in 43% of all reports. The authors precisely defined early recognised oesophageal intubation and delayed or unrecognised oesophageal intubation. Most reports (74%) described early recognition of the misplaced intubation, of which 27% led to directly contributed to hypoxia. Cardiovascular collapse as a direct consequence of the late recognition of oesophageal intubation was described in five (18%) of these events. There was inconsistency in end-tidal carbon dioxide monitoring and interpretation of the resulting waveform. Findings show that oesophageal intubation continues to be an issue in anaesthesia. Incidents described confusion in diagnosis, human factors issues and cognitive bias. Clear diagnostic guidance and treatment strategies are required to be developed, tested and implemented.

Multi-Modal Assessment of Cerebral Hemodynamics in Resuscitated Out-of-Hospital Cardiac Arrest Patients: A Case-Series.

We assessed the feasibility of concurrent monitoring of cerebral hemodynamics in adult, comatose out-of-hospital cardiac arrest (OHCA) patients admitted to the National University Heart Centre Singapore from October 2021 to August 2023. Patients underwent continuous near-infrared spectroscopy (NIRS) monitoring in the first 72 h after return of spontaneous circulation (ROSC) and 30-min transcranial Doppler ultrasound (TCD) monitoring at least once. With constant mechanical ventilatory settings and continuous electrocardiographic, pulse oximeter and end-tidal carbon dioxide monitoring, blood pressure was manipulated via vasopressors and cerebral autoregulation assessed by measuring changes in regional cerebral oxygenation (NIRS) and cerebral blood flow velocities (TCD) in response to changes in mean arterial pressure. The primary outcome was neurological recovery at hospital discharge. Amongst the first 16 patients (median age 61, 94% males), we observed four unique patterns: preserved cerebral autoregulation, loss of cerebral autoregulation, cardio-cerebral asynchrony and cerebral circulatory arrest. Patients with preserved cerebral autoregulation had lower levels of neuro-injury biomarkers (neurofilaments light and heavy) and the majority (86%) were discharged with good neurological recovery. Multi-modal assessment of cerebral hemodynamics after OHCA is feasible and derived patterns correlated with neurological outcomes. The between- and within-patient heterogeneity in cerebral hemodynamics calls for more research on individualized treatment strategies.

End-tidal carbon dioxide and arterial to end-tidal carbon dioxide gradient are associated with mortality in patients with neurological injuries

Pre-hospital end-tidal carbon dioxide (EtCO2) monitoring and arterial to end-tidal carbon dioxide gradient (Pa-EtCO2) have been associated with mortality in patients with traumatic brain injury. Our study aimed to analyze the association between alveolar EtCO2 or Pa-EtCO2 and mortality in patients admitted in intensive care unit (ICU) with neurological injuries. In our retrospective analysis from using large de-identified ICU databases (MIMIC-III and -IV and eICU databases), we included 2872 ICU patients with neurological injuries, identified according to the International Classification of Diseases (ICD-9 and -10), who underwent EtCO2 monitoring. We performed logistic regression and extended Cox regression to assess the association between mortality and candidate covariates, including EtCO2 and Pa-EtCO2. In-hospital mortality was 26% (n = 747). In univariate analysis, both the Pa-EtCO2 gradient and EtCO2 levels during the first 24 h were significantly associated with mortality (for a 1 mmHg increase: OR = 1.03 [CI95 1.016–1.035] and OR = 0.94 [CI95 0.923–0.953]; p < 0.001). The association remained significant in multivariate analysis. The time-varying evolution of EtCO2 was independently associated with mortality (for a 1 mmHg increase: HR = 0.976 [CI95 0.966–0.985]; p < 0.001). The time-varying Pa-EtCO2 gradient was associated with mortality only in univariate analysis. In neurocritical patients, lower EtCO2 levels at admission and throughout the ICU stay were independently associated with mortality and should be avoided.

End-Tidal Carbon Dioxide Monitoring in Anesthesia: Unraveling the Mysteries of Respiratory and Circulatory Physiology

The present article underscored the indispensable significance of end-tidal carbon dioxide (ETCO2) monitoring in anesthesia and critical care, offering critical insights into both ventilation and metabolism dynamics. The meticulous management of tidal volume, respiratory rate, and inspired oxygen levels during anesthesia plays a pivotal role in maintaining optimal arterial oxygen and carbon dioxide concentrations. Effective ventilation is imperative for proper gas exchange within the alveoli and maintaining a stable acid-base balance. In the context of circulatory physiology during anesthesia, cardiac output, blood pressure, and tissue perfusion hold paramount importance. The present article highlights how anesthesia-induced alterations in vascular tone and cardiac function could influence circulation and tissue oxygenation, impacting parameters like blood pressure, heart rate, and ETCO2. Monitoring these parameters provides essential data for assessing circulatory status, guiding anesthesia management, and averting complications. ETCO2 monitoring has evolved into a standard practice in anesthesia and critical care settings, offering real-time, non-invasive insights. The present article delved into the extensive clinical applications, challenges, and future directions of ETCO2 monitoring. Encompassing fundamental principles, technological nuances, clinical implications, limitations, and avenues for research, this article advanced the understanding of this monitoring technique and its positive impact on patient care. The present article also discussed how ETCO2 levels reflect alveolar ventilation, providing critical data for assessing ventilation adequacy, readiness for extubation, and identification of impending respiratory distress. Furthermore, it delved into how ETCO2 levels serve as an indicator of cardiac output and tissue perfusion, guiding management strategies in various shock states and offering prognostic insights during CPR. Challenges and limitations associated with ETCO2 monitoring were clarified, with emphasis on technical considerations, patient populations with specific challenges, and potential interpretation pitfalls. The article outlines the exciting future directions of ETCO2 monitoring, encompassing wearable technology, remote monitoring capabilities, artificial intelligence integration, and potential applications beyond traditional realms. Keywords: Anesthesia; Capnography; Critical care; End-tidal carbon dioxide; ETCO2 monitoring

Research Progress on End-Tidal Carbon Dioxide Detection Technology Based on Non-Dispersive Infrared Method

The concentration of end-tidal carbon dioxide is one of the important indicators for evaluating whether the human respiratory system is normal. Accurately detecting of end-tidal carbon dioxide is of great significance in clinical practice. With the continuous promotion of the localization of end-tidal carbon dioxide monitoring technology, its application in clinical practice in China has become increasingly widespread in recent years. The study is based on the non-dispersive infrared method and comprehensively elaborates on the detection principle, gas sampling methods, key technologies, and technological progress of end-tidal carbon dioxide detection technology. It comprehensively introduces the current development status of this technology and provides reference for application promotion and further improvement.

Does end-tidal carbon dioxide monitoring in gastrointestinal endoscopy have a clinical advantage?

Aims: In current guidelines recommended CO2 monitoring for patient safety and comfort in sedation for gastrointestinal endoscopy. We aimed to investigate whether carbon dioxide monitoring, which was developed for the early detection of adverse respiratory events shows the expected benefit in its clinical use.&#x0D; Methods: Asa I-II patients, average age 48±15, were divided into two groups, standard monitoring was performed on Group S (n=30), and EtCO2, Integrated Pulmonary Index measurements were added to the Group K (n=30). Patients received Fentanyl 1µgr/kg, propofol 1 mg/kg and propofol 10-30 mg in a bolus by providing BIS to be 60-85. Adverse respiratory events were recorded. The time to Fast-tracking score being 14 was recorded and patients with two consecutive Fast-tracking scores of 14 were discharged. Patient satisfaction was questioned the next day.&#x0D; Results: There is no difference between groups in heart rate and mean arterial pressure, and decreased during the procedure compared to baseline in both groups. While EtCO2 was similar at all times, IPI was lower than baseline. While the processing time was 21±6 in Group S, it was 38±11 in Group K. No adverse respiratory events occurred. Recovery heart rates, peripheral oxygen saturation, mean arterial pressure and scores were similar. There was no difference in patient satisfaction.&#x0D; Conclusions: There wasn’t a clinical advantage with measuring EtCO2 added to the standard monitoring in gastrointestinal tract endoscopy. We believe that more studies are needed on optimum monitoring during moderate sedation in patients with less clinical risk.

Prehospital end-tidal carbon dioxide measurement

The prehospital environment presents numerous challenges regarding the diagnosis and subsequent management of critically ill patients—diagnostic aids are limited; point-of-care testing is almost universally unavailable and senior medical advice can be beyond timely reach. Pulse oximetry provides real-time assessment of peripheral tissue oxygen saturation, but not of ventilation adequacy. The past decade has seen the gradual introduction of end-tidal carbon dioxide monitoring or capnography into routine resuscitation practice following successive national audit reports, coronial reports and subsequent guidance regarding safe airway management. However, capnography alone does not prevent adverse outcomes, particularly if it is not properly interpreted. Capnography is now regarded as essential monitoring whenever airway management or ventilation is required. The increasing availability of capnography in the prehospital setting can provide dynamic, real-time information that can aid assessment and treatment of pathology at the first point of contact and direct onward management. This article reviews the pathophysiology associated with the production, transport and excretion of carbon dioxide and suggests a number of ways in which accurate measurement and interpretation can potentially be a useful diagnostic tool and inform management choices in the prehospital setting.

Progress of end-tidal carbon dioxide monitoring in non-intubated patients

End-tidal carbon dioxide (ETCO2) monitoring is an important tool for assessing respiratory and circulatory status of patients. It has become an integral component of perioperative anesthesia care in patients undergoing general anesthesia with endotracheal intubation. ETCO2 monitoring can also benefit non-intubated patients. This review covers the basics of ETCO2 and methods of partial pressure of ETCO2 (PETCO2) monitoring and focuses on the literature regarding PETCO2 monitoring for non-intubated patients. Most studies explored the superiority of PETCO2 monitoring in patients under sedation outside operating room, while others investigated the potential advantages of PETCO2 monitoring in other scenarios such as post-anesthesia care unit, cardiopulmonary resuscitation, and patient-controlled analgesia. As carbon dioxide detection technology and sampling circuits continue to improve, PETCO2 monitoring is expected to be used in more medical scenarios.

Technical validation of the EMMA capnometer under hyperbaric conditions.

End-tidal carbon dioxide (ETCO2) monitoring is essential for monitoring intubated critical care patients, yet its use in hyperbaric environments can be problematic. We postulated that the EMMA mainstream capnometer may function accurately under hyperbaric conditions. Stage 1. The EMMA mainstream capnometer was tested at 101 kPa against a reference side-stream capnometer, Philips IntelliVue M3015B microstream, using 10 customised reference gases of various carbon dioxide (CO₂) concentrations (2.47%-8.09%, or 18.5-60.7 mmHg at 101 kPa) in either air or oxygen. Stage 2. The functionality and accuracy of the EMMA capnometer was tested under hyperbaric conditions, 121-281 kPa, using the same test gases. At 101 kPa, the EMMA capnometer measured CO₂ at levels lower than expected (mean of differences = -2.5 mmHg (95% CI -2.1 to -2.9, P < 0.001)). The Philips capnometer measured CO₂ more closely to expected CO₂ (mean of differences = -1.1 mmHg (95% CI -0.69 to -1.4, P < 0.001). Both devices demonstrated a significant linear relationship with expected CO₂. The EMMA capnometer functioned up to the maximum test pressure (281 kPa). The device over-read CO₂ measurements at pressures > 141 kPa. Although variance increased at pressures in the therapeutic range for hyperbaric treatments, a significant linear relationship between expected and EMMA measured CO₂ was demonstrated. The EMMA capnometer tolerated pressures to 281 kPa, but its display was limited to CO₂ < 99 mmHg. This study validated EMMA capnometer function to 281 kPa in the hyperbaric environment. The device over-read CO₂ measurements at pressures >141 kPa, however there was a linear relationship between expected and measured CO₂. The EMMA capnometer may be clinically useful for monitoring expired CO₂ in patients undergoing hyperbaric oxygen treatment.

Dynamic Lateral Semisitting Position for Supracerebellar Approaches: Technical Note and Case Series.

It has always been a matter of debate which position is ideal for the supracerebellar approach. The risk of venous air embolism (VAE) is the major deterrent for surgeons and anesthesiologists, despite the fact that sitting and semisitting positions are commonly used in these operations. To demonstrate a reduction on the risk of VAE and tension pneumocephalus throughout the operation period while taking advantages of the semisitting position. In this study, 11 patients with various diagnoses were operated in our department using the supracerebellar approach in the dynamic lateral semisitting position. We used end-tidal carbon dioxide and arterial blood pressure monitoring to detect venous air embolism. None of the patients had clinically significant VAE in this study. No tension pneumocephalus or major complications were observed. All the patients were extubated safely after surgery. The ideal position, with which to apply the supracerebellar approach, is still a challenge. In our study, we presented an alternative position that has advantages of the sitting and semisitting positions with a lower risk of venous air embolism.

Benchmarking Hospital Practices and Policies on Intrahospital Neurocritical Care Transport: The Safe-Neuro-Transport Study.

An electronic survey was administered to multidisciplinary neurocritical care providers at 365 hospitals in 32 countries to describe intrahospital transport (IHT) practices of neurocritically ill patients at their institutions. The reported IHT practices were stratified by World Bank country income level. Variability between high-income (HIC) and low/middle-income (LMIC) groups, as well as variability between hospitals within countries, were expressed as counts/percentages and intracluster correlation coefficients (ICCs) with a 95% confidence interval (CI). A total of 246 hospitals (67% response rate; n = 103, 42% HIC and n = 143, 58% LMIC) participated. LMIC hospitals were less likely to report a portable CT scanner (RR 0.39, 95% CI [0.23; 0.67]), more likely to report a pre-IHT checklist (RR 2.18, 95% CI [1.53; 3.11]), and more likely to report that intensive care unit (ICU) physicians routinely participated in IHTs (RR 1.33, 95% CI [1.02; 1.72]). Between- and across-country variation were highest for pre-IHT external ventricular drain clamp tolerance (reported by 40% of the hospitals, ICC 0.22, 95% CI 0.00-0.46) and end-tidal carbon dioxide monitoring during IHT (reported by 29% of the hospitals, ICC 0.46, 95% CI 0.07-0.71). Brain tissue oxygenation monitoring during IHT was reported by only 9% of the participating hospitals. An IHT standard operating procedure (SOP)/hospital policy (HP) was reported by 37% (n = 90); HIC: 43% (n= 44) vs. LMIC: 32% (n = 46), p = 0.56. Amongst the IHT SOP/HPs reviewed (n = 13), 90% did not address the continuation of hemodynamic and neurophysiological monitoring during IHT. In conclusion, the development of a neurocritical-care-specific IHT SOP/HP as well as the alignment of practices related to the IHT of neurocritically ill patients are urgent unmet needs. Inconsistent standards related to neurophysiological monitoring during IHT warrant in-depth scrutiny across hospitals and suggest a need for international guidelines for neurocritical care IHT.

Transcutaneous Carbon Dioxide Monitoring More Accurately Detects Hypercapnia than End-Tidal Carbon Dioxide Monitoring during Non-Intubated Video-Assisted Thoracic Surgery: A Retrospective Cohort Study

Transcutaneous carbon dioxide (PtcCO2) monitoring is known to be effective at estimating the arterial partial pressure of carbon dioxide (PaCO2) in patients with sedation-induced respiratory depression. We aimed to investigate the accuracy of PtcCO2 monitoring to measure PaCO2 and its sensitivity to detect hypercapnia (PaCO2 > 60 mmHg) compared to nasal end-tidal carbon dioxide (PetCO2) monitoring during non-intubated video-assisted thoracoscopic surgery (VATS). This retrospective study included patients undergoing non-intubated VATS from December 2019 to May 2021. Datasets of PetCO2, PtcCO2, and PaCO2 measured simultaneously were extracted from patient records. Overall, 111 datasets of CO2 monitoring during one-lung ventilation (OLV) were collected from 43 patients. PtcCO2 had higher sensitivity and predictive power for hypercapnia during OLV than PetCO2 (84.6% vs. 15.4%, p < 0.001; area under the receiver operating characteristic curve; 0.912 vs. 0.776, p = 0.002). Moreover, PtcCO2 was more in agreement with PaCO2 than PetCO2, indicated by a lower bias (bias ± standard deviation; -1.6 ± 6.5 mmHg vs. 14.3 ± 8.4 mmHg, p < 0.001) and narrower limit of agreement (-14.3-11.2 mmHg vs. -2.2-30.7 mmHg). These results suggest that concurrent PtcCO2 monitoring allows anesthesiologists to provide safer respiratory management for patients undergoing non-intubated VATS.

Respiratory function monitoring during early resuscitation and prediction of outcomes in prematurely born infants.

Over the last decade, there has been increased use of end-tidal carbon dioxide (ETCO2) and oxygen saturation (SpO2) monitoring during resuscitation of prematurely born infants in the delivery suite. Our objectives were to test the hypotheses that low end-tidal carbon dioxide (ETCO2) levels, low oxygen saturations (SpO2) and high expiratory tidal volumes (VTE) during the early stages of resuscitation would be associated with adverse outcomes in preterm infants. Respiratory recordings made in the first 10 min of resuscitation in the delivery suite of 60 infants, median GA 27 (interquartile range 25-29) weeks were analysed. The results were compared of infants who did ordid not die or did or did not develop intracerebral haemorrhage (ICH) or bronchopulmonary dysplasia (BPD). Twenty-five infants (42%) developed an ICH and23 (47%) BPD; 11 (18%) died. ETCO2 at approximately 5min after birth was lower in infants who developed anICH, this remained significant after adjusting for gestational age, coagulopathy and chorioamnionitis (p=0.03). ETCO2 levels were lower in infants who developed ICH or died compared to those that survived without ICH, which remained significant after adjustment for gestational age, Apgar score at 10min, chorioamnionitis and coagulopathy (p=0.004). SpO2 at approximately 5min waslower in the infants who died compared to those who survived which remained significant after adjusting for the5-min Apgar score and chorioamnionitis (p=0.021). ETCO2 and SpO2 levels during early resuscitation in the delivery suite were associated with adverse outcomes.

Combined use of Jackson Rees circuit with end-tidal carbon dioxide monitoring: an easy and safer technique during awake blind nasal intubation

Combined use of Jackson Rees circuit with end-tidal carbon dioxide monitoring: an easy and safer technique during awake blind nasal intubation

Therapeutic Implications of Monitoring End-tidal Carbon Dioxide in SubMassive Pulmonary Embolism

While managing submassive pulmonary embolism in Intensive Care Unit, it is always a challenge to identify the parameters to identify the deterioration. It is important to understand it as further therapeutic decision about the use of thrombolytics is based on its recognition. Bedside monitoring of end-tidal carbon dioxide which is readily available, continuous, noninvasive, and nonoperator dependent can be of help in deciding on the need of thrombolytics in such cases before development of hypotension.

At-home end-tidal carbon dioxide measurement in children with invasive home mechanical ventilation.

Carbon dioxide concentration trending is used in chronic management of children with invasive home mechanical ventilation (HMV) in clinical settings, but options for end-tidal carbon dioxide (EtCO2 ) monitoring at home are limited. We hypothesized that a palm-sized, portable endotracheal capnograph (PEC) that measures EtCO2 could be adapted for in-home use in children with HMV. We evaluated the internal consistency of the PEC by calculating an intraclass correlation coefficient of threeback-to-back breaths by children (0-17 years) at baseline health in the clinic. Pearson's correlation was calculated for PEC EtCO2 values with concurrent mean values of in-clinic EtCO2 and transcutaneous CO2 (TCM) capnometers. The Bland-Altman test determined their level of agreement. Qualitative interviews and surveys assessed usability and acceptability by family-caregivers at home. CO2 values were collected in awake children in varied activity levels and positions (N = 30). The intraclass correlation coefficient for the PEC was 0.95 (p < 0.05). The correlation between the PEC and in-clinic EtCO2 device was 0.85 with a mean difference of -3.8 mmHg and precision of ±1.1 mmHg. The correlation between the PEC and the clinic TCM device was 0.92 with a mean difference of 0.2 mmHg and precision of ±1.0. Family-caregivers (N = 10) trialed the PEC at home; all were able to obtain measurements at home while children were awake and sometimes asleep. A portable, noninvasive device for measuring EtCO2 was feasible and acceptable, with values that trend similarly to currently in-practice, outpatient models. These devices may facilitate monitoring of EtCO2 at home in children with invasive HMV.

Accuracy evaluation of mainstream and sidestream end-tidal carbon dioxide monitoring during noninvasive ventilation: a randomized crossover trial (MASCAT-NIV trial)

BackgroundThe end-tidal partial pressure of carbon dioxide (PETCO2) can be used to estimate the arterial partial pressure of carbon dioxide (PaCO2) in patients who undergo mechanical ventilation via endotracheal intubation. However, no reliable method for measuring PETCO2 during noninvasive ventilation (NIV) has been established. The purpose of this study was to evaluate the correlation and agreement between PaCO2 and PETCO2 measured by these two methods and to compare them in patients who underwent NIV after extubation.MethodsThis study was a randomized, open-label, crossover trial in a mixed intensive care unit. We included patients who were planned for NIV after extubation and for whom the difference between PETCO2 and PaCO2 was ≤ 5 mmHg. We compared mainstream capnography using an inner cup via face mask (the novel method) with sidestream capnography (the previous method) during NIV. The relationships between PaCO2 and PETCO2 were evaluated by computing the Pearson correlation coefficient, and the agreement between PaCO2 and PETCO2 was estimated using the Bland–Altman method.ResultsFrom April 2020 to October 2021, 60 patients were included to the study. PaCO2 and PETCO2 were well correlated in both methods (the novel methods: r = 0.92, P < 0.001; the previous method: r = 0.79, P < 0.001). Mean bias between PaCO2 and PETCO2 measured using the novel method was 2.70 (95% confidence interval [CI], 2.15–3.26) mmHg with 95% limits of agreement (LoA) ranging from − 1.61 to 7.02 mmHg, similar to the result of measurement during SBT (mean bias, 2.51; 95% CI, 2.00–3.02; 95% LoA, − 1.45 to 6.47 mmHg). In contrast, measurement using the previous method demonstrated a larger difference (mean bias, 6.22; 95% CI, 5.22–7.23; 95% LoA, − 1.54 to 13.99 mmHg).ConclusionThe current study demonstrated that the novel PETCO2 measurement was superior to the previous method for PaCO2 prediction. During NIV, the novel method may collect as sufficient exhalation sample as during intubation. Continuous PETCO2 measurement combined with peripheral oxygen saturation monitoring is expected to be useful for early recognition of respiratory failure among high-risk patients after extubation.Trial registration UMIN-CTR UMIN000039459. Registered February 11, 2020.

Point-of-Care Ultrasound Use by EMS Providers in Out-of-Hospital Cardiac Arrest.

Paramedics received training in point-of-care ultrasound (POCUS) to assess for cardiac contractility during management of medical out-of-hospital cardiac arrest (OHCA). The primary outcome was the percentage of adequate POCUS video acquisition and accurate video interpretation during OHCA resuscitations. Secondary outcomes included POCUS impact on patient management and resuscitation protocol adherence. A prospective, observational cohort study of paramedics was performed following a four-hour training session, which included a didactic lecture and hands-on POCUS instruction. The Prehospital Echocardiogram in Cardiac Arrest (PECA) protocol was developed and integrated into the resuscitation algorithm for medical non-shockable OHCA. The ultrasound (US) images were reviewed by a single POCUS expert investigator to determine the adequacy of the POCUS video acquisition and accuracy of the video interpretation. Change in patient management and resuscitation protocol adherence data, including end-tidal carbon dioxide (EtCO2) monitoring following advanced airway placement, adrenaline administration, and compression pauses under ten seconds, were queried from the prehospital electronic health record (EHR). Captured images were deemed adequate in 42/49 (85.7%) scans and paramedic interpretation of sonography was accurate in 43/49 (87.7%) scans. The POCUS results altered patient management in 14/49 (28.6%) cases. Paramedics adhered to EtCO2 monitoring in 36/36 (100.0%) patients with an advanced airway, adrenaline administration for 38/38 (100.0%) patients, and compression pauses under ten seconds for 36/38 (94.7%) patients. Paramedics were able to accurately obtain and interpret cardiac POCUS videos during medical OHCA while adhering to a resuscitation protocol. These findings suggest that POCUS can be effectively integrated into paramedic protocols for medical OHCA.