End-tidal Carbon Dioxide Monitoring Research Articles

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

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

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.
 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.
 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.
 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.

Naloxone Use for Opioid Reversal in Patients with Sickle Cell Disease

Patients with sickle cell disease (SCD) are known to require increased dosing of drugs including opioids due to differences in renal and hepatic metabolism. While it is known that SCD patients require higher opioid doses to achieve the same degree of analgesia, it is not clear if this is associated with a similar increase in drug toxicities. A significant risk of opioid use is respiratory depression, and naloxone is used for rapid reversal of this adverse effect. In the setting of a nationwide opioid shortage in 2018, our institution established a policy requiring the use of patient-controlled analgesia (PCA) rather than intravenous push (IVP) for hospitalized SCD patients. This coincided with a mandate for end tidal carbon dioxide (ETCO) monitoring with PCA use, effectively implementing ETCO in the routine care of this population. In this study, we describe our experience using naloxone for opioid reversal in hospitalized SCD patients.We studied naloxone use in patients admitted to the University of Illinois at Chicago for two 24-month time periods (July 31, 2015 - July 31, 2017 and May 1, 2018 - May 1, 2020). These dates were chosen to compare naloxone use before and after implementation of ETCO monitoring. A pharmacy reporting tool was used to identify every dose of naloxone administered within the hospital during these dates. We isolated patients on the inpatient sickle cell service and compared the proportion of SCD patients between study periods using Fisher's exact test. For SCD patients who received naloxone, we obtained baseline patient characteristics and divided doses into episodes when multiple doses were given within a day. For each episode, we studied analgesic regimens, details of the hospitalization, and laboratory values. Given the small data sample, we used descriptive statistics for analysis.Among 931 total naloxone doses given in the two time periods, 35 were given to SCD patients. Out of 580 total distinct patients, there were 14 patients admitted to the sickle cell service. There were 5 out of 279 (1.8%) SCD patients who received 12 out of 443 (2.7%) doses between July 2015 and July 2017. There were 10 out of 309 (3.2%) SCD patients who received 23 out of 488 (4.7%) doses between May 2018 and May 2020. There was no significant difference in naloxone use by SCD patients before and after implementation of ETCO. For the two time periods combined, there were 14 out of 580 (2.4%) SCD patients who received 35 out of 931 (3.8%) doses. We were able to manually confirm 10 SCD patients and 17 episodes of naloxone use by chart review. Among these, 2 patients who only had 1 episode each received naloxone in the absence of opioid overdose. One patient with multiple episodes had an episode of receiving naloxone for opioid overdose not involving hospital-administered medications. Among the remaining 8 SCD patients who appropriately received naloxone for opioid reversal in the hospital, 100% were black or African American race. Seven (87.5%) out of 8 had Hgb SS genotype, and male-to-female ratio was 1:1. Six out of 14 (42.9%) episodes occurred when patients were not receiving their usual pain regimen. Vaso-occlusive crisis was a diagnosis for 13 out of 14 (92.9%) episodes. A median of 2 doses of naloxone were given per episode. Median creatinine clearance was 20.85 mL/min, and several cases coincided with acute kidney injury. Median sedation scale score prior to naloxone dose was 1 (minimally sedated). One patient was treated with a naloxone continuous infusion.Our study highlights the relatively low use of naloxone in patients with SCD despite generally high usage of opioids. Nearly every patient admitted to the sickle cell service utilizes opioid pain medications, but the proportion of naloxone use in SCD patients is small. There was no significant difference in naloxone use after policy changes instituted the use of ETCO, but this may be due to sample size. The low rates of naloxone use in SCD patients may be related to mechanisms of hyperfiltration that necessitate increased opioid dosing. Our results suggest that the higher observed opioid dosages are not associated with worsened toxicities in SCD patients. With techniques such as ETCO, SCD patients can more safely be treated for pain using opioid medications, and providers should be mindful of pertinent pharmacological factors when caring for this population. DisclosuresSaraf: Pfizer: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

A national survey of capnography utilization among anaesthesiologists in Indonesia

BackgroundCapnography allows health-care providers to continuously monitor the concentration or partial pressure of carbon dioxide in respiratory gas. The American Society of Anaesthesiologists includes end-tidal carbon dioxide monitoring as mandatory monitoring for patients under sedation and anaesthesia. However, capnography is not widely considered for standard patient monitoring in Indonesia. We aim to investigate the utilization of capnography and reasons for lack of use among anaesthesiologists in Indonesia. MethodsAn internet-based questionnaire was distributed to participants of an online anaesthesiology national meeting. Data was collected and managed using REDCap electronic data capture tools hosted at Faculty of Medicine Universitas Indonesia. ResultsWe received 421 respondents' replies nationwide. Replies from anaesthesiologists (n = 367) was used for data analysis. 55.3% (n = 203) reported the availability of capnography in their hospitals. Approximately 77 (21%) of respondents utilize capnography routinely for intraoperative monitoring, 132 (36%) never use capnography. Only 59 (16%) routinely use capnography for intubation confirmation. The utilization of capnography outside the operating theatre was even lower. As many of 249 (67.9%) never use capnography for monitoring during procedural sedation, while 278 (75.8%) do not utilize capnography during patient transfer. ConclusionThe utilization of capnography for intraoperative monitoring is adopted only by half of anaesthesiologists in Indonesia. Outside the operating theatre capnography use is still limited. Capnography as a standard of care should be implemented in all health care institutions in Indonesia.

Effect of ETCO2 monitoring of poisoning patients with decreased mental state in ED

Purpose: This study aimed to analyse the effect of End-Tidal Carbon Dioxide (ETCO2) monitoring on patients who had been poisoned and presented in the emergency department with decreased consciousness. Methods: The data of patients over 18 years old presenting with poisoning from 2016 to 2020 was collected from the emergency department. We retrospectively analyzed their medical records, and defined patients with a Glasgow Coma Scale (GCS) score of 9 or less as having decreased consciousness. We divided the patients into two groups, one with ETCO2 monitoring and the other without, and the difference between the two groups was compared. Results: 168 patients participated in this study and 83 (49.4%) of them belonged to the ETCO2 monitoring group. In this group, the interval between arterial blood tests was statistically significantly longer and the rate of intubation was lower. In addition, in the monitoring group, the incidence of pneumonia and the rate of poor prognosis was not significantly higher. Conclusion: Although ETCO2 monitoring does not directly affect the prognosis of poisoned patients with decreased consciousness, it should be actively done as it can help to adequately treat patients while avoiding invasive techniques or unnecessary intubation.

Polysomnography parameters as predictors of respiratory adverse events following adenotonsillectomy in children

The first-line treatment of obstructive sleep apnea syndrome in children is adenotonsillectomy, but this may result in perioperative respiratory adverse events (PRAEs). The primary aim of this study is to examine whether the McGill oximetry score (MOS) and other polysomnography parameters can predict major PRAEs following adenotonsillectomy. We secondarily evaluated the MOS interrater reliability and correlation with other polysomnography parameters. This retrospective study included all children aged 0-18 years who underwent preoperative polysomnography between June 2010 and January 2016 prior to adenotonsillectomy at a tertiary pediatric institution. Oximetries from polysomnograms were assigned an MOS. Univariable and multivariable models for prediction of major PRAEs were constructed. MOS was correlated with polysomnography parameters and interrater reliability was evaluated. This study included 106 children; 15 had a major PRAE. A multivariable prediction model that combined MOS and age showed evidence for the ability to predict major PRAEs with an area under the receiver operating characteristic curve of 0.68 (95% confidence interval: 0.52, 0.84), whereby increased MOS and younger age were associated with PRAEs, but apnea-hypopnea index was not. MOS had excellent interrater reliability (κ = 0.95) and was highly correlated with oxygen saturation nadir and cumulative time percentage with oxygen saturation less than 90%. A prediction model including MOS and age may predict PRAEs following adenotonsillectomy. This suggests that nocturnal oximetry provides the most essential information of polysomnography measures to direct postoperative monitoring following adenotonsillectomy. Xiao L, Barrowman N, Momoli F, etal. Polysomnography parameters as predictors of respiratory adverse events following adenotonsillectomy in children. J Clin Sleep Med. 2021;17(11):2215-2223.

Respiratory Monitoring During Gamma Knife Radiosurgery: Anesthesiological Aspects.

Gamma Knife surgery (GKS) is a minimally invasive neurosurgical procedure, generally performed under moderate sedation along with local analgesia for fixation of a stereotactic frame to the patient's head, and is managed mostly by nonanesthesiologists. There are some risks for respiratory function during GKS and definite specifics for its management, since the presence of the stereotactic frame may impede access to the patient's airway and interfere with direct visual observation of him or her by medical personnel. Continuous monitoring for early detection of respiratory depression and timely intervention in the event of an emergency seem essential during radiosurgical procedures, but no relevant standards have been established to date. Since hypoventilation appears in advance of desaturation, sole monitoring of peripheral oxygen saturation (SpO2) by pulse oximetry is insufficient for detection of an early respiratory decline. According to the American Society of Anesthesiologists (ASA) practice guidelines for sedation and analgesia by nonanesthesiologists, the adequacy of ventilation during moderate and deep sedation should be evaluated by continuous observation of qualitative clinical signs and monitoring of end-tidal carbon dioxide (EtCO2). Overall, combined use of pulse oximetry and capnography may be recommended during GKS and may enhance its safety, especially in cases of medically fragile, uncooperative, or pediatric patients.