ETCO2 Monitoring Research Articles

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.

2024 RECOVER Guidelines: Monitoring. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR.

To systematically review evidence on and devise treatment recommendations for patient monitoring before, during, and following CPR in dogs and cats, and to identify critical knowledge gaps. Standardized, systematic evaluation of literature pertinent to peri-CPR monitoring following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by Monitoring Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4weeks prior to finalization. Transdisciplinary, international collaboration in university, specialty, and emergency practice. Thirteen questions pertaining to hemodynamic, respiratory, and metabolic monitoring practices for identification of cardiopulmonary arrest, quality of CPR, and postcardiac arrest care were examined, and 24 treatment recommendations were formulated. Of these, 5 recommendations pertained to aspects of end-tidal CO2 (ETco2) measurement. The recommendations were founded predominantly on very low quality of evidence, with some based on expert opinion. The Monitoring Domain authors continue to support initiation of chest compressions without pulse palpation. We recommend multimodal monitoring of patients at risk of cardiopulmonary arrest, at risk of re-arrest, or under general anesthesia. This report highlights the utility of ETco2 monitoring to verify correct intubation, identify return of spontaneous circulation, evaluate quality of CPR, and guide basic life support measures. Treatment recommendations further suggest intra-arrest evaluation of electrolytes (ie, potassium and calcium), as these may inform outcome-relevant interventions.

Does the Addition of Oral Sampling Improve Waveform Capnography When Compared to Traditional Nasal Sampling in Open-Airway Patients?

BackgroundEnd-tidal carbon dioxide (EtCO2) is an invaluable anesthesia measure due to minimal delay in monitoring ventilation. Oral and Maxillofacial Surgery (OMS) presents special challenges because oral exhalations are not sampled effectively via nasal cannula normally used to avoid interfering with procedures. PurposeThe purpose of the study was to compare EtCO2 waveforms obtained in subjects using nasal monitoring and combined nasal and oral monitoring under simulated ventilatory conditions. Study design, setting, sampleA single-blinded, randomized crossover controlled study was conducted at the University of Illinois Chicago with healthy volunteers, who were blinded to the monitoring system used. Inclusion criteria required subjects be >18 years of age, be consentable and English-speaking. Exclusion criteria required no airway abnormalities, no edentulism, no conditions that preclude undergoing an OMS procedure under sedation. Predictor variableThe primary predictor variable was the EtCO2 monitoring system: nasal with a standard nasal cannula, and combined with a nasal cannula and oral device. The secondary predictor variable evaluated three ventilatory states (nasal breathing, oral breathing, apnea) in each arm, standardizing by maintaining consistent breath counts across observation periods. Main outcome variableThe main outcome variable was the number of waveforms recorded over 30 seconds for nasal and combined monitoring. Each recording was standardized by dividing it by the baseline waveforms and multiplying by 20. Higher values, closer to baseline, were considered more accurate depictions of ventilation. CovariatesCovariates were body mass index (BMI), age, sex, Mallampati score, and breathing method. AnalysesANOVA, ANCOVA, and MANOVA were performed. P-value<0.05 was considered statistically significant. ResultsThe sample included 25 subjects (18 male, 7 female) with mean age 29.9+7.98 years and BMI 23.9+3.51 kg/m2. Combined sampling detected more waveforms during nasal and oral breathing (p<0.001). Higher BMI correlated with reduced waveform capture during nasal sampling in oral breathing (p=0.013). Combined sampling detected more waveforms during nasal breathing (p=0.005) in subjects with BMI < 23.5 kg/m2. Mallampati score correlated with increased waveforms during nasal breathing. Conclusions and RelevanceOral EtCO2 sampling may improve accuracy of capnography waveform capture. Further clinical studies in sedated subjects undergoing OMS procedures are needed.

Anaesthetic Management for Rt Emphysematous Pyelonephritis with Grade I Hydroureteronephrosis with Perinephric Abscess with Left Lobar Pneumonia

ntroduction: A perinephric abscess is usually a complication of urologic infection which results from fat necrosis. Before the era of antibiotics, perinephric abscesses were due to prolonged bacteremia. More than 3/4 of perinephric abscesses are now due to complications of urinary tract infections. Case Report: We present a 71 year old female case with Right Emphysematous Pyelonephritis Grade I Hydroureteronephrosis with left perinephric abscess, left lobar pneumonia posted for bilateral DJ stenting with perinephric drain placement under continuous spinal anesthesia. Presented with H/o lower back pain, associated with fever since 3 days and H/o burning micturition, since 6 months. She is known case of Type 2 DM since 23 years and on Inj. Biphasic Insulin, Tablet vildagliptin, Tablet Dapaglifazone, known case of hypothyroidism and on tablet Thyroxin 50 mg OD in morning. H/o stroke 20 years back right side Upper &amp; lower limb affected. H/o previous appendectomy 20 years back, CT–KKUB suggestive of Emphysematous Pyelonephritis, right side with grade I HUN, left perinephric fat with ill diffused hypodense area in upper lobe of left kidney. Non obstructive left renal calculus 4.0mm. ECG shows RBBB, Saturation was 92% on Roomair, On ABG analysis severe metabolic acidosis found. We planned to administer continuous spinal anesthesia. Patient was explained about the continuous spinal anesthesia &amp; written informed consent was taken. Tablet Alprazolam 0.25 mg, and tablet Rantac, 15 was given previous night and in morning on the day of surgery. Nil per oral is maintained 8 hours before surgery. A 18 Gauge IV cannula was secured, a 5 lead Electrocardiogram, Pulse Oximeter, NIBP and ETCo2 monitoring was done. Under strict aseptic precautions, L3 L4 space was identified and using 18G tuhoy needle, Lumbar puncture is done. Injection Bupivacaine 0.8cc given, block is achieved till T8 level. Surgery was lasted for one and half hour. Vitals were stable. Patient shifted to recovery room and was under observation for an hour, patient was shifted to post operative ward. Conclusion: This is an Original case report, which provide a successful management of anesthesia, of bilateral DJ stenting with perinephric drain placement under continuous spinal anesthesia. Anesthesia Management for Right Emphysematous Pylonephritis with grade I HUN. With perinephric abscess with left lobar Pneumonia.

Observational Cross-Sectional Study of ETCO2 and Pulse Oximetry for Early Detection of Hypoxia in MAC Patient (Monitored Anaesthesia Care)

Background and Aim: The study aims to identify whether ETCO2 detects early hypoxia compared to monitoring of SpO2, HR and RR (Standard Monitor) in patients undergoing surgical procedure under MAC. Method: Total 336 patients belonging to Age group of 18-60 years, ASA grade 1 and grade 2, procedure lasting for &lt;4hrs, undergoing sedation under MAC for day care surgery. Measurements of Spo2, HR, RR, ETCO2, NIBP done by applying monitors. Nasal cannula also put for supplemental Oxygen. Result: Overall 92 episodes of disordered ventilation were detected out of which 67 were detected by ETCO2 (44- Hypoventilation and 23- Apnoea) and 25 were detected by Pulse Oximetry (4- Hypoventilation and 21- desaturation. Overall a mean delay of 51.04 seconds was seen in detection by Pulse Oximetry. Conclusion: In the study it was concluded that patients under sedation, underwent frequent episodes of disordered ventilation leading to hypoxia. In such scenarios it was seen that ETCO2 monitoring provided a practical advantage of detecting hypoventilation and apnea earlier than Pulse Oximetry showing desaturation. Keywords: Capnography, ETCO2, pulse oximetry.

Prehospital Use of Waveform Capnography in Intubated Neonates

Introduction Routine continuous monitoring of endotracheal tube placement with waveform capnography is considered standard of care in the prehospital setting. However, maintaining this standard in neonatal patients remains a challenge due to low tidal volumes that do not tolerate the additional dead space ETCO2 attachments add. Additionally, continuous ETCO2 can increase the risk of ETT dislodgement or kinking because of the weight and size of the capnography attachments relative to the patient and tube size. We hypothesize that there is a gap in care of intubated neonates when compared to adults in the prehospital setting in terms of continuous monitoring of ETT placement. Methods Data were obtained from a single air medical agency. Through a retrospective chart review, records of intubated neonates (<28 days), children (≥28 days–12 years), adolescents (13–18 years), and adults (aged ≥18 years) were analyzed. Records were available from 11/21/13–1/21/22. The number of intubation attempts, whether an intubation was successful, and the use of capnography were recorded in RedCap. Statistical analysis was performed in Microsoft Excel via Chi Square Goodness of Fit Tests. Results During the study period, 674 intubation attempts were identified, and 28 charts were excluded due to missing patient age. Continuous waveform ETCO2 monitoring was used on 62%, 94%, 95%, and 97% of successfully intubated neonates, children, adolescents, and adults, respectively. There was a statistically significant difference between use of continuous waveform capnography in adults and neonates (p-value = 0.013). There was also a statistically significant difference between use of continuous waveform capnography in intubated neonates, children, and adolescents (p-value = 0.049). Conclusion Continuous ETCO2 monitoring is underutilized in intubated neonates compared to children, adolescents, and adults in the prehospital setting in this study population. This suggests a gap in the standard of care provided to neonates. Additional studies are needed to determine if these results are consistent around the industry and if there is a higher rate of undetected tube displacement in neonates who are transported without waveform capnography.

The Use of End-Tidal CO2 and Integrated Pulmonary Index to Predict Postspinal Hypotension in Cesarean Section.

Early diagnosis and treatment of postspinal hypotension (PSH) in obstetric anaesthesia reduces the risk of maternofetal complications. In this study, the effect of EtCO2 and the integrated pulmonary index (IPI) in predicting PSH was investigated. Patients scheduled for cesarean section under spinal anaesthesia were included. The Capnostream 35 respiratory monitor (Medtronic, Inc., Dublin, Ireland) was used for EtCO2 and IPI. PSH developed in 52 (63.4%) of the 82 patients. EtCO2 and IPI values decreased significantly compared with baseline values in patients who developed PSH. There were statistically significant differences in EtCO2 (p = 0.001) and the IPI change (p = 0.045) in patients who developed PSH compared with those who did not. It was found that the EtCO2 difference had an independent effect on predicting PSH (p < 0.05), whereas the IPI difference did not (p > 0.05). One unit decrease in EtCO2 from the baseline increased the risk of PSH by 3.3 times. ROC curve analysis showed that the magnitude of change in EtCO2 was diagnostic for predicting PSH (AUC: 0.90 (0.83-0.97; p < 0.001)). IPI showed no predictive value for postspinal hypotension in cesarean section. However, EtCO2 monitoring, which is non-invasive and real-time monitoring, can be used to predict postspinal hypotension.

The Association of Prehospital End-Tidal Carbon Dioxide with Survival Following Out-of-Hospital Cardiac Arrest

Objective End tidal carbon dioxide (ETCO2) is often used to assess ventilation and perfusion during cardiac arrest resuscitation. However, few data exist evaluating the relationship between ETCO2 values and mortality in the context of contemporary resuscitation practices. We aimed to explore the association between ETCO2 and mortality following out-of-hospital cardiac arrest (OHCA). Methods We used the 2018–2021 ESO annual datasets to query all non-traumatic OHCA patients with attempted resuscitation. Patients with documented DNR/POLST, EMS-witnessed arrest, ROSC after bystander CPR only, or < 2 documented ETCO2 values were excluded. The lowest and highest ETCO2 values recorded during the total prehospital interval, in addition to the pre- and post-ROSC intervals for resuscitated patients, were calculated. Multivariable logistic regression models adjusted for age, sex, initial rhythm, witnessed status, bystander CPR, etiology, OHCA location, sodium bicarbonate administration, number of milligrams of epinephrine administered, and response interval were used to evaluate the association between measures of ETCO2 and mortality. Results Hospital outcome data were available for 14,122 patients, and 2,209 (15.6%) were classified as surviving to discharge. Compared to patients with maximum prehospital ETCO2 values of 30–40 mmHg, odds of mortality were increased for patients with maximum prehospital ETCO2 values of <20 mmHg (aOR: 3.5 [2.1, 5,9]), 20–29 mmHg (aOR: 1.5 [1.1, 2.1]), and >50 mmHg (aOR: 1.5 [1.2, 1.8]). After 20 minutes of ETCO2 monitoring, <12% of patients had ETCO2 values <10 mmHg. This cutpoint was 96.7% specific and 6.9% sensitive for mortality. Conclusion In this dataset, both high and low ETCO2 values were associated with increased mortality. Contemporary resuscitation practices may make low ETCO2 values uncommon, and field termination decision algorithms should not use ETCO2 values in isolation.

Early warning: End-tidal carbon dioxide is associated with central venous oxygenation under continuous cardiorespiratory monitoring in a porcine model of hemorrhagic shock and resuscitation

BackgroundEnd-tidal carbon dioxide (ETCO2) has previously shown promise as a predictor of shock severity and mortality in trauma. ETCO2 monitoring is non-invasive, real-time, and readily available in prehospital settings, but the temporal relationship of ETCO2 to systemic oxygen transport has not been thoroughly investigated in the context of hemorrhagic shock. MethodsA validated porcine model of hemorrhagic shock and resuscitation was used in male Yorkshire swine (N ​= ​7). Both ETCO2 and central venous oxygenation (SCVO2) were monitored and recorded continuously in addition to other traditional hemodynamic variables. ResultsLinear regression analysis showed that ETCO2 was associated with ScvO2 both throughout the experiment (β ​= ​1.783, 95% confidence interval (CI) [1.552–2.014], p ​< ​0.001) and during the period of most rapid hemorrhage (β ​= ​4.896, 95% CI [2.416–7.377], p ​< ​0.001) when there was a marked decrease in ETCO2. ConclusionsETCO2 and ScvO2 were closely associated during rapid hemorrhage and continued to be temporally associated throughout shock and resuscitation.

COMPARISON OF KETAMINE-MIDAZOLAM AND KETAMINE-MIDAZOLAM-BUTORPHANOL PREMEDICATION PRIOR TO SEVOFLURANE ANESTHESIA IN WOODCHUCKS (MARMOTA MONAX).

Cardiovascular disease is a frequent cause of death in the critically endangered Vancouver Island marmots (Marmota vancouverensis). This warrants the use of anesthetic protocols with minimal cardiovascular adverse effects. In this study, 12 adult male woodchucks (Marmota monax) were used as models for Vancouver Island marmots. The objective was to compare the physiological effects of two premedication protocols during induction and maintenance of anesthesia with sevoflurane. The two premedications were ketamine 10 mg/kg and midazolam 0.5 mg/kg (KM) or ketamine 10 mg/kg, midazolam 0.5 mg/kg, and butorphanol 1.0 mg/kg (KMB), administered intramuscularly prior to mask induction. Each marmot underwent three anesthetic events and protocols were assigned using a blinded randomized crossover design. Heart rate, respiratory rate, oxygen saturation, and body temperature were recorded throughout, and blood gases were assessed following induction. Resistance to induction was scored and time to induction was recorded. Although mask induction with sevoflurane was successful in all events (mean induction time of 2.1 min), KMB premedication resulted in a faster induction (mean induction time reduced by 1.2 ± 0.3 min) and lower resistance scores. Both protocols resulted in significant cardiovascular and respiratory depression; however, animals that received KMB were more hypercapnic than KM by 8.8 ± 2.8 mm Hg (P = 0.03) (mean venous partial pressure of carbon dioxide [PvCO2] for all: 79.9 mm Hg). In conclusion, if shorter induction times are desired, KMB premedication is preferred. However, cardiorespiratory variables including blood pressure should be monitored, and endotracheal intubation is recommended to allow for ETCO2 monitoring and provision of intermittent positive pressure ventilation.

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.

Trending Ability of End-Tidal Capnography Monitoring During Mechanical Ventilation to Track Changes in Arterial Partial Pressure of Carbon Dioxide in Critically Ill Patients With Acute Brain Injury: A Monocenter Retrospective Study.

Changes in arterial partial pressure of carbon dioxide (Pa co2 ) may alter cerebral perfusion in critically ill patients with acute brain injury. Consequently, international guidelines recommend normocapnia in mechanically ventilated patients with acute brain injury. The measurement of end-tidal capnography (Et co2 ) allows its approximation. Our objective was to report the agreement between trends in Et co2 and Pa co2 during mechanical ventilation in patients with acute brain injury. Retrospective monocenter study was conducted for 2 years. Critically ill patients with acute brain injury who required mechanical ventilation with continuous Et co2 monitoring and with 2 or more arterial gas were included. The agreement was evaluated according to the Bland and Altman analysis for repeated measurements with calculation of bias, and upper and lower limits of agreement. The directional concordance rate of changes between Et co2 and Pa co2 was evaluated with a 4-quadrant plot. A polar plot analysis was performed using the Critchley methods. We analyzed the data of 255 patients with a total of 3923 paired ΔEt co2 and ΔPa co2 (9 values per patient in median). Mean bias by Bland and Altman analysis was -8.1 (95 CI, -7.9 to -8.3) mm Hg. The directional concordance rate between Et co2 and Pa co2 was 55.8%. The mean radial bias by polar plot analysis was -4.4° (95% CI, -5.5 to -3.3) with radial limit of agreement (LOA) of ±62.8° with radial LOA 95% CI of ±1.9°. Our results question the performance of trending ability of Et co2 to track changes in Pa co2 in a population of critically ill patients with acute brain injury. Changes in Et co2 largely failed to follow changes in Pa co2 in both direction (ie, low concordance rate) and magnitude (ie, large radial LOA). These results need to be confirmed in prospective studies to minimize the risk of bias.

Capnometry during neonatal transport-Mini review.

The aim of this review was to give an overview of available data on end-tidal CO2 (etCO2 ) monitoring, also called capnometry, during neonatal transport. Pubmed/MEDLINE database was searched using research question (capno* OR etCO2 OR detCO2 OR (['end tidal' OR 'end-tidal'] AND [CO2 OR 'carbon dioxide']) AND (neonat* OR infant* OR newborn*) AND transport*). All articles relevant to the topic were reviewed and summarised. The lack of studies relevant to neonatal transport prompted us to extend the search to capnometry in a neonatal intensive care setting. The published studies are showing conflicting results. The different study populations, technologies used to measure etCO2 , types of etCO2 sampling and the diverse sites of blood gas tests make the data unsuitable for systematic comparison. Further research to obtain more data on capnometry during neonatal transport will be necessary to define precisely under what circumstances can end-tidal monitoring of CO2 be reliably used in neonates during transport and also how to interpret the measured values.

Non-invasive carbon dioxide monitoring during moderate sedation at different oxygen flow rates in patients undergoing endoscopic retrograde cholangio-pancreatography

ABSTRACT Background All patients receiving sedation to facilitate endoscopic procedures should have monitoring of cardiorespiratory parameters before, during, and after administration of sedation/analgesia. We evaluated the effects of different O2 flow rates on the non-invasive CO2 monitoring (EtCO2) in adult patients that were breathing spontaneously under moderate sedation during ERCP. Methods This prospective randomized double-blind study was conducted on 120 patients assigned randomly to one of the three equal groups (n = 40) (Group I; 2 L/min oxygen flow rate, Group II; 4 L/min oxygen flow rate, and Group III; 6 L/min oxygen flow rate). Primary outcome was EtCO2 at the end of procedure. Secondary outcomes included peripheral O2 saturation, hemodynamics, time to recovery, total propofol dose, patients’ satisfaction, sedation score, and complications. Results EtCO2 increased significantly between the studied groups at pre-intervention, induction, 5, 10, 20, and 30 min but without any clinical significance (p-value ˂ 0.05). The HR changes were statistically significant at 10 and 20 min after induction of anesthesia. While SpO2, MBP, and RR differences were statistically not significant between groups throughout the whole study periods (p-value >0.05). Arterial blood gas analysis showed PCO2 was significantly different between the study groups but still within the normal range of readings, while pH and HCO3 showed statistically insignificant differences between the three groups. Conclusion The study demonstrated that different O2 flow rates did not affect the non-invasive EtCO2 measurements by the Dual-Guard device during moderate sedation in patients undergoing ERCP. Non-invasive EtCO2 monitoring can provide an early warning sign of hypoventilation during moderate sedation.

Quantitative end-tidal carbon dioxide at initiation of resuscitation may help guide the ventilation of infants born at less than 30 weeks gestation.

Estimation of end-tidal carbon dioxide (EtCO2 ) with capnography can guide mask ventilation in infants born at less than 30 weeks of gestation. Chemical-sensitive colorimetric devices to detect CO2 are widely used at resuscitation. We aimed to quantify EtCO2 in the first breaths following initiation of mask ventilation at birth and correlated need for endotracheal intubation. Infants <30 weeks gestation receiving mask ventilation were randomised into two groups of mask-hold technique (one-person vs. two-person). Data on EtCO2 in the first 30 breaths, time to achieve 5 mmHg, 10 mmHg and 15 mmHg CO2 using a respiratory function monitor was determined. Twenty-five infants with a mean gestation of 27.3 (±3 weeks) and mean birth weight 920.4 (±188.3g) were analysed. The median EtCO2 was 5.6 mmHg in the first 10 breaths, whereas it was 12.6 mmHg for 11-20 breaths and 18 mmHg for 21-30 breaths. There was no significant difference in maximum median EtCO2 for the first 20 breaths, although EtCO2 was significantly lower in infants who were intubated (32.0 vs. 15.0, p=0.018). EtCO2 monitoring in infants <30 weeks gestation at birth is feasible and reflective of alveolar ventilation. EtCO2 may help guide ventilation of preterm infants at birth.

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

The purpose of this study was to assess the effectiveness of an educational program about measuring ventilation using devices that assess carbon dioxide levels in patients recovering from a surgical procedure. A pre-post survey of knowledge attainment from an educational intervention about measuring ventilation using end-tidal carbon dioxide (EtCO2) and transcutaneous carbon dioxide (tcPCO2) devices in the postanesthesia care unit (PACU) was distributed to current members of the American Society of PeriAnesthesia Nurses. Participants received a 12-question pre-intervention (five were related to demographics) and a five-question post-intervention survey. Non-demographic survey questions used a one to five Likert scale to assess comfortability or confidence. The intervention created was a voice-over presentation designed to improve PACU RN's comfort and confidence with using and interpreting tcPCO2 or EtCO2 in the PACU. PACU RNs (N=108) reported they 'never' or 'rarely' used EtCO2 (n=57, 52.7%) monitoring or tcPCO2 (n=93, 86.1%) monitoring in the PACU. A paired t test revealed statistically significant differences in the PACU RN's pre-survey and posttest comfortability of applying and interpreting EtCO2 or tcPCO2 monitors (P < .05). Capnography monitoring should be considered a standard of care for PACU patients. Education of registered nurses working in the PACU is critical before implementing EtCO2 or tcPCO2 monitoring.

0729 Assessing the Diagnostic Benefit of Polysomnography with Routine Carbon Dioxide Measurements in Adolescent and Adult Obese Patients

Abstract Introduction The diagnosis of obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS) has increased with the increasing prevalence of obesity. Adding routine transcutaneous carbon dioxide (TcCO2) or end-tidal carbon dioxide sensors (EtCO2) to a polysomnogram (PSG) may expand the analytic capabilities of the study. Our study looks at the utility of using CO2 monitoring in obese adolescent (age 13-18 years) and obese adults in increasing the diagnostic yield of the polysomnogram. Methods A retrospective chart review was conducted on obese adolescents (13-18 years) and obese adults (body mass index [BMI] &amp;gt; 95 percentile and &amp;gt;30 kg/m2 respectively) undergoing a PSG with EtCO2 monitoring. The CO2 values were documented while supine (awake) and while sleeping. The EtCO2 value was correlated with the BMI but the adults were also compared between Group 1 (BMI 30-40 kg/m2) and Group 2 (BMI &amp;gt;40 kg/m2). Patients with known hypoventilation syndromes or studies that had poor EtCO2 waveforms were excluded. Results 72 patients were identified between December 2019 and November 2020 at the Memorial Hermann Sleep Disorders Center. Amongst the adults, 52% were men, with an average age of 55 years (range 26-77) and an average BMI 40.5 kg/m2 (SD +/- 8.8). The average AHI on the diagnostic study (CMS criteria) was 31 events/hour (SD +/- 34.1) and the average oxygen saturation nadir was 80%. Twenty patients (28%) met the diagnostic criteria for OHS based on the baseline awake EtCO2. The mean EtCO2 was 40.1 mmHg in patients with a BMI between 30 and 40 kg/m2 (Group 1) versus 45.1 mmHg in patients with BMI &amp;gt;40 kg/m2 (Group 2) with a statistically significant p-value of 0.0002. Additionally, we identified 18 patients between the ages of 13-18 years with obesity amongst which, 4 patients also had a baseline EtCO2 of &amp;gt;45 torr (22%) with a potential diagnosis of OHS. Conclusion Patients diagnosed with OHS are reported to have a higher overall greater mortality. Our study suggests a higher diagnostic yield of OHS in adults and adolescents with the use of CO2 monitoring especially in the morbidly obese. This evidence would advocate for the routine use of CO2 monitoring in the obese patient population. Support (If Any)

How to avoid rapid carbon dioxide changes at the start of veno-venous extracorporeal membrane oxygenation: Role of end-tidal CO2 monitoring.

Background: Venovenous ECMO is a lifesaving technique for patients with severe respiratory failure. Management of carbon dioxide (CO2) levels at ECMO start is crucial, as recent studies found an association between rapid CO2 shifts and increased incidence of neurological complications.Purpose: To describe the role of end tidal CO2 (etCO2) monitoring at the ECMO start to minimize carbon dioxide shifts.Research design: Retrospective cohort study.Methods: We performed a retrospective analysis of patients who started venovenous ECMO support at our institution between 2011 and 2021. We analysed the minute-by-minute variations of etCO2, ventilatory parameters and arterial blood gas before and after the ECMO start.Results: 36 patients with a complete dataset of parameters were included. After the ECMO start, minute ventilation was progressively reduced from 10.8±;3.3 to 2.9±1.2 L/min (p<0.001). etCO2 did not vary significantly (baseline 37±10 vs 35±9 mmHg 20 minutes after ECMO start, p = 0.36). Despite a stable etCO2 level, a mild drop of arterial CO2 tension (9.5 mmHg, corresponding to a 18% change) was recorded at the first ABG sampled after the ECMO start. No patient developed neurological complications after the ECMO commencement.Conclusion: etCO2 monitoring during ECMO start is feasible and allows to adjust gas flow and ventilator settings to limit changes in arterial CO2 levels.

Factors affecting the arterial to end-tidal carbon dioxide gradient in ventilated neonates

Objective. To determine factors which influenced the relationship between blood carbon dioxide (pCO2) and end-tidal carbon dioxide (EtCO2) values in ventilated, newborn infants. Furthermore, to assess whether pCO2 levels could be predicted from continuous EtCO2 monitoring. Approach. An observational study of routinely monitored newborn infants requiring mechanical ventilation in the first 28 d after birth was undertaken. Infants received standard clinical care. Daily pCO2 and EtCO2 levels were recorded and the difference (gradient: ∆P-EtCO2) between the pairs were calculated. Ventilatory settings corresponding to the time of each blood gas assessment were noted. End-tidal capnography monitoring was performed using the Microstream sidestream Filterline H set capnograph. Main results. A total of 4697 blood gas results from one hundred and fifty infants were analysed. The infants had a median gestational age of 33.3 (range 22.3–42.0) weeks and birth weight of 1880 (395–5520) grams. Overall, there was moderate correlation between pCO2 and EtCO2 levels (r = 0.65, p < 0.001). The ∆P-EtCO2 for infants born less than 32 weeks of gestation was significantly higher (1.4 kPa) compared to infants born at greater than 32 weeks of gestation (0.8 kPa) (p < 0.001). In infants born at less than 32 completed weeks of gestation, pCO2 levels were independently associated with EtCO2, day after birth, birthweight and fraction of inspired oxygen (FiO2) (model r 2 = 0.52, p < 0.001). Significance. The results of end-tidal capnography monitoring have the potential to predict blood carbon dioxide values within the neonatal population.

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.