End-tidal Carbon Dioxide Levels Research Articles

Low intraoperative end-tidal carbon dioxide levels are associated with improved recurrence-free survival after elective colorectal cancer surgery

Study objectiveHigher levels of carbon dioxide (CO2) increase the invasive abilities of colon cancer cells in vitro. Studies assessing target values for end-tidal CO2 concentrations (EtCO2) to improve surgical outcome after colorectal cancer surgery are lacking. Therefore, we evaluated whether intraoperative EtCO2 was associated with differences in recurrence-free survival after elective colorectal cancer (CRC) surgery. DesignSingle center, retrospective analysis. SettingAnesthesia records, surgical databases and hospital information system of a tertiary university hospital. PatientsWe analyzed 528 patients undergoing elective resection of colorectal cancer at Heidelberg University Hospital between 2009 and 2018. InterventionsNone. MeasurementsIntraoperative mean EtCO2 values were calculated. The study cohort was equally stratified into low-and high-EtCO2 groups. The primary endpoint measure was recurrence-free survival until last known follow-up. Groups were compared using Kaplan-Meier analysis. Cox-regression analysis was used to control for covariates. Sepsis, reoperations, surgical site infections and cardiovascular events during hospital stay, and overall survival were secondary outcomes. Main resultsMean EtCO2 was 33.8 mmHg ±1.2 in the low- EtCO2 group vs. 37.3 mmHg ±1.6 in the high-EtCO2 group. Median follow-up was 3.8 (Q1-Q3, 2.5–5.1) years. Recurrence-free survival was higher in the low-EtCO2 group (log-rank-test: p = .024). After correction for confounding factors, lower EtCO2 was associated with increased recurrence-free survival (HR = 1.138, 95%-CI:1.015–1.276, p = .027); the hazard for the primary outcome decreased by 12.1% per 1 mmHg decrease in mean EtCO2. 1-year and 5-year survival was also higher in the low-EtCO2 group. We did not find differences in the other secondary endpoints. ConclusionsLower intraoperative EtCO2 target values in CRC surgery might benefit oncological outcome and should be evaluated in confirmative studies.

A comparative study between serum lactate level versus change in end tidal carbon dioxide level regarding assessment of hemodynamic instability in intensive care unit patients after cardiac surgeries

ABSTRACT Background After cardiac surgeries, elevated lactate level is used as a marker of tissue hypoperfusion. Still, there is a search for other helpful markers of hemodynamic instability. Exhaled carbon dioxide has been recently studied as marker of cardiac output and tissue perfusion and may be considered a reliable alternative which is more convenient and real time. Objectives The main aim is to correlate between end tidal carbon dioxide (ETCO2) and serum lactate level as indicators of hemodynamic instability in intensive care unit (ICU) patients after cardiac surgeries. The secondary objective is to correlate the measured parameters to the changes in the vital data and the resuscitation efforts. Methods A prospective cohort study that enrolled 51 adult patients admitted to ICU after cardiac surgeries. The serum lactate and ETCO2 values as well as vital data and vasopressor doses were recorded on admission to ICU, after 2 hours and after 6 hours. Results The study shows insignificant weak positive correlation between Lactate and ETCO2 levels at admission (r = 0.172, p value = 0.229), and insignificant negative weak correlation after 2 hours (r = -0.148, p value = 0.300) and after 6 hours (r = -0.235, p value = 0.096). Moreover, lactate level showed significant direct relation with the doses of vasopressors at admission, after 2 hours and after 6 hours postoperative (p value < 0.001 at all intervals). Whereas there was insignificant relation between ETCO2 and doses of vasopressors at all intervals (p value = 0.23, 0.4 and 0.18 respectively). Conclusion In post-cardiac surgery ICU patients we detected no statistically significant relation between serum lactate and ETCO2 as indicators of hemodynamic instability. The change in ETCO2 over a period of time has failed so far to be of a beneficial value as a non-invasive real-time cardiac output monitoring parameter. In addition, serum lactate had strong correlation with changes in vital signs and resuscitation efforts.

Tracheal injury diagnosed by a sudden increase in end-tidal carbon dioxide levels during mediastinoscopic subtotal esophagectomy: a case report

BackgroundMediastinoscopic surgery for esophageal cancer facilitates early postoperative recovery. However, it can occasionally cause serious complications. Here, we present the case of a patient with a tracheal injury diagnosed by a sudden increase in end-tidal carbon dioxide (EtCO2) during mediastinoscopic subtotal esophagectomy.Case presentationA 52-year-old man diagnosed with esophageal cancer was scheduled to undergo mediastinoscopic subtotal esophagectomy. During the mediastinoscopic procedure, the EtCO2 level suddenly increased above 200 mmHg, and the blood pressure dropped below 80 mmHg. We immediately asked the operator to stop insufflation and found a tracheal injury on the right side of the trachea near the carina by bronchoscopy. The endotracheal tube was replaced with a double-lumen tube, and the trachea was repaired via right thoracotomy. There were no further intraoperative complications. After surgery, the patient was extubated and admitted to the intensive care unit.ConclusionsMonitoring EtCO2 levels and close communication with the operator is important for safely managing sudden tracheal injury during mediastinoscopic esophagectomy.

Evaluation of the relationship between end-tidal carbon dioxide level and heart failure classification.

Heart failure is a disease with cardiac dysfunction, and its morbidity and mortality are associated with the degree of dysfunction. The New York Heart Association classifies the heart failure stages based on the severity of symptoms and physical activity. End-tidal carbon dioxide refers to the level of carbon dioxide that a person exhales with each breath. End-tidal carbon dioxide levels can be used in many clinical conditions such as heart failure, asthma, and chronic obstructive pulmonary disease. The aim of the study was to reveal the relationship between end-tidal carbon dioxide levels and the New York Heart Association classification of heart failure stages. This study was conducted at Kahramanmaraş Sütçü İmam University Faculty of Medicine Adult Emergency Department between 01/03/2019 and 01/09/2019. A total of 80 patients who presented to the emergency department with a history of heart failure or were diagnosed with heart failure during admission were grouped according to the New York Heart Association classification of heart failure stages. The laboratory parameters, ejection fraction values, and end-tidal carbon dioxide levels of the patients were measured and recorded in the study forms. End-tidal carbon dioxide levels and ejection fraction values were found to be significantly lower in the stage 4 group compared to the other groups. Furthermore, pro-B-type natriuretic peptide (BNP) values were found to be significantly higher in stage 4 group compared to the other groups. It was concluded that end-tidal carbon dioxide levels could be used together with pro-BNP and ejection fraction values in determining the severity of heart failure.

Comparative Analysis of Haemodynamic and Capnographic Changes in Laparoscopic Cholecystectomy and Open Cholecystectomy: A Randomised Clinical Study

Introduction: Laparoscopic cholecystectomy is now preferred over the open procedure due to advantages such as reduced blood loss and shorter hospital stays. However, concerns have been raised regarding the potential for increased Intra-abdominal Pressure (IAP) during laparoscopic procedures, which may impact haemodynamic stability and respiratory parameters. However, there is a lack of comprehensive analysis directly comparing both surgical approaches from both haemodynamic and capnographic perspectives. Aim: To compare the haemodynamic and capnographic changes between laparoscopic and open cholecystectomy. Materials and Methods: This randomised clinical study was conducted at Department of Anaesthesiology, Assam Medical College and Hospital, Dibrugarh, Assam, India from May 2021 to June 2022. The study included 300 patients scheduled for cholecystectomy, divided into two groups: Laparoscopic Cholecystectomy (LC) Group I (n=150) and Open Cholecystectomy (OC) Group II (n=150). Haemodynamic parameters, including Pulse Rate (PR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), and Oxygen Saturation (SpO2 ), were recorded. Capnographic parameters, such as End-Tidal Carbon Dioxide (EtCO2 ) levels, were also measured at regular intervals. Data analysis was performed using the student’s t-test and Chi-square test with Statistical Package for Social Sciences (SPSS) version 21.0 software and Microsoft excel. Results: There were no significant differences in age, body weight, and sex distribution between Group I and Group II. However, significant differences were observed in PR and SBP at 15 minutes (PR: 101.46 and 95.86; SBP: 148.57 and 140.97), 30 minutes (PR: 104.52 and 99.82; SBP: 141.28 and 136.07), and 45 minutes (PR: 102.52 and 97.70; SBP: 140.59 and 133.95) (p-value &lt;0.01). Highly significant differences were observed in MAP and EtCO2 postinsufflation at 15 minutes (MAP: 118.38 and 108.61; EtCO2: 36.48 and 33.89), 30 minutes (MAP: 111.11 and 106.01; EtCO2: 41.02 and 36.15), 45 minutes (MAP: 110.73 and 103.48; EtCO2: 42.65 and 38.36), and 60 minutes (MAP: 106.08 and 101.45; EtCO2: 41.10 and 38.21) (p-value &lt;0.01). DBP showed high significance at 15 minutes (103.21 and 93.23), 30 minutes (96.74 and 92.57), and 60 minutes (93.14 and 86.92) (p-value &lt;0.01), and significant (p-value=0.01) at 45 minutes (95.53 and 87.59). Oxygen saturation showed significance (p-value &lt;0.05) at 15 minutes (99.93 and 100). Conclusion: The present study demonstrated a significant increase in both haemodynamic and capnographic parameters, even in American Society of Anaesthesiologists (ASA) Grade-I and Grade-II patients undergoing laparoscopic cholecystectomy compared to the open surgical technique. These findings emphasise the need for careful monitoring during laparoscopic procedures.

A neonatal in-vitro study on the effect of the inflation pressure on end-tidal carbon dioxide levels.

Describing the association of the peak inflation pressure (PIP) with end-tidal carbon dioxide (ETCO2) is a prerequisite for the development of closed loop ventilation in neonatal intensive care. We aimed to develop an in-vitro system to study this relationship. A ventilator was connected to a test lung, supplied with a stable CO2 concentration from a cylinder. The PIP was altered and the change in ETCO2 per unit of PIP was calculated in three models mimicking respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD) and viral bronchiolitis. The median (IQR) change in ETCO2 per unit of PIP was 0.23(0.13-0.38) kPa/cmH2O, using 138 paired measurements of PIP and ETCO2. The median (IQR) change in ETCO2 per unit of PIP, was higher when starting at an ETCO2>6kPa [0.43(0.33-0.58) kPa/cmH2O] compared to starting at an ETCO2<6kPa [0.14(0.08-0.20) kPa/cmH2O, p<0.001]. The median (IQR) change in ETCO2 per unit of PIP, was larger in the model of RDS [0.33(0.13-0.51) kPa/cmH2O] compared to the BPD [0.23(0.13-0.33) kPa/cmH2O, p=0.043] and the bronchiolitis models [0.15(0.10-0.31) kPa/cmH2O, p=0.017]. The change in ETCO2 in response to increasing PIP was larger for higher ETCO2 values and in a model simulating neonatal RDS, compared to BPD and bronchiolitis.

EtCO2 Levels in Medical Students Wearing N95 Masks

Introduction: N95 masks are very popular for daily use and can actively filter microparticles such as viruses. However, there are concerns that prolonged wearing of the mask may result in exhaled CO2 accumulation between the face and the mask, which may cause increased end-tidal carbon dioxide (EtCO2) levels and physiological changes. This study aimed to determine EtCO2 levels in students wearing the N95 mask. Methods: This was an experimental study with a case-control design. The subjects were divided into a treatment and a control group and were subjected to five measurements in 120 minutes. The data were analyzed using the independent samples T-test (normally distributed data) and the Mann-Whitney U test (not normally distributed data). Results: Mann-Whitney test at minute 0 showed that p = 0.010, independent sample T-test at minute 30 showed that the control group p = 0.016, while in the treatment group p = 0.019. Independent sample T-test at minute 60 for the control group p = 0.034, while the treatment group p = 0.037. Independent sample T-test at minute 90 for the control group and treatment p = 0.001, and independent sample T-test showed that at minute 120 in the control and treatment groups p = 0.000. Conclusion: The EtCO2 measurements at each of the five time points showed a statistical difference (p &lt; 0.05). However, medical students who wore an N95 mask did not suffer adverse effects because the EtCO2 values in the control group were higher than in the treatment group.

Pitfalls in the Diagnosis of Peri-Operative Acute Pulmonary Embolism: A Case Report

An 80 years-old man with hypertension, atrial fibrillation, and coronary artery occlusion disease presented for an elective right femur bipolar hip arthroplasty under general anesthesia. Preoperative transthoracic echocardiography (TTE) showed only preexisting regional wall motion abnormality. During the reversal of muscular relaxation following surgery, there was a sudden decrease in blood pressure associated with rapid ventricular response, which was successfully treated by cardioversion. No decrease in end-tidal carbon dioxide level was observed during the hypotensive episode. However, despite fluid and blood resuscitation and vasopressor treatment, there was a repeated hemodynamic collapse postoperatively. A portable TTE showed dilated right atrium and right ventricle (RV), D-shaped left ventricle, and septal wall motion abnormalities consistent with RV pressure overload (McConnell’s sign). Computed tomography pulmonary angiography revealed multifocal PE (pulmonary embolism). Anticoagulation therapy was continued to avoid PE recurrence. The patient discharged uneventfully 30 days later. Perioperative PE is a rare and perhaps dangerous circumstance that can be challenging to diagnose when it happens under anesthesia. The likelihood of PE should always be suspected at the time of perioperative hemodynamic collapse.

Arterial versus end-tidal carbon dioxide levels in children with congenital heart disease: a prospective cohort study in patients undergoing pulmonary catheterization.

Fifty-seven children with congenital heart disease who underwent cardiopulmonary catheterization between March 2018 and April 2019 were included in a prospective cohort study at Children's Medical Center. Arterial and end-tidal CO2, and hemodynamic variables were assessed prior to the catheterization procedure. Then the patients underwent catheterization, and before being extubated, these variables were again assessed and compared to the baseline levels. End-tidal CO2 increased significantly in cyanotic patients following the catheterization procedure, and the difference between arterial and end-tidal CO2 decreased significantly. End-tidal CO2, arterial CO2, and their difference did not significantly change in non-cyanotic patients following the catheterization procedure. End-tidal and arterial CO2 were not significantly correlated in cyanotic patients (r=0.411, P=0.128), but they were correlated after the catheterization procedure (r=0.617, P=0.014). End-tidal CO2 can estimate arterial CO2 in non-cyanotic patients reasonably. End-tidal CO2 cannot be used to estimate arterial CO2 in cyanotic patients since there is no association. After cardiac defect correction, end-tidal CO2 can be a reliable predictor of arterial CO2.

The Effect of Supine Cycling and Progressive Lower Body Negative Pressure on Cerebral Blood Velocity Responses.

Moderate-intensity aerobic exercise increases cerebral blood velocity (CBv) primarily due to hyperpnea-induced vasodilation; however, the integrative control of cerebral blood flow (CBF) allows other factors to contribute to vasodilation. Lower body negative pressure (LBNP) can reduce CBv, the exact LBNP-intensity required to blunt the aforementioned exercise-induced CBv response is unknown. This could hold utility for concussion recovery, allowing individuals to exercise at higher-intensities without symptom exacerbation. Thirty-two healthy adults (age: 20-33 years; 19 females) completed a stepwise maximal-exercise test to determine each participant's wattage associated with their exercise-induced maximal CBv increase. During the second visit, participants completed moderate-intensity exercise at their determined threshold, while progressive LBNP was applied at 0, -20, -40, -60, -70, -80, and ~88 Torr. Bilateral middle cerebral artery blood velocities (MCAv), mean arterial pressure (MAP), heart rate, respiratory rate, and end-tidal carbon dioxide levels were measured continuously. Two-way analysis of variance with effect sizes compared between sexes and stages. Compared to resting-supine baseline, averaged MCAv was elevated during 0 and -20 Torr LBNP (q-value>7.73; p<0.001); no differences were noted between baseline and -40 to -70 Torr (q-value<|4.24|; p>0.262). Differences were present between females and males for absolute MCAv measures (q-value>11.2; p<0.001), but not when normalized to baseline (q-value<0.03; p>0.951). Supine cycling-elicited increases in MCAv were blunted during the application of LBNP ranging from -40 to -70 Torr. The blunted CBv response demonstrates the potential benefit of allowing individuals to aerobically train (moderate-intensity supine cycling with LBNP) without exacerbating symptoms during concussion recovery.

Does a change in end-tidal carbon dioxide level predict high altitude mountain sickness?

BackgroundIt is postulated that lack of hypoxic ventilatory response is a predictor for AMS. End-tidal carbon dioxide (ETCO2) is an accurate, noninvasive surrogate measure of ventilation. ObjectivesWe sought to determine if changes in baseline ETCO2 predicts the development of AMS. MethodsThis prospective cohort study took place in three separate high-altitude hiking treks. Subjects included a convenience sample of hikers. Predictor variable was change in ETCO2 levels and outcome variable was AMS. Measurements of ETCO2 levels were obtained at the base and repeated daily at various elevations and the summit of each hike. Concurrently, hikers were scored for AMS by a trained investigator. We utilized correlation coefficients and developed a linear regression model for analysis. Results21 subjects in 3 separate hikes participated: 10 ascended to 19,341 ft over 7 days, 6 ascended to 8900 ft in 1 day, and 4 ascended to 11,006 ft in 1 day. Mean age was 40 years, 67% were males, mean daily elevation gain was 2150 ft, and 5 hikers developed AMS. The correlation coefficients for ETCO2 and development of AMS were −0.46 (95%CI -0.33 to −0.57), and −0.77 (95%CI -0.71 to −0.83) for ETCO2 and altitude. ETCO2 predicted the development of symptoms better than the elevation with AUCs of 0.90 (95%CI 0.81–0.99) versus 0.64 (95%CI 0.45–0.83). An ETCO2 measurement of ≤22 mmHg was 100% sensitive and 60% specific for predicting AMS. ConclusionsETCO2 was strongly correlated with altitude and moderately correlated with AMS and it was a better predictor than altitude.

Association between prehospital end-tidal carbon dioxide levels and mortality in patients with suspected severe traumatic brain injury

PurposeSevere traumatic brain injury is a leading cause of mortality and morbidity, and these patients are frequently intubated in the prehospital setting. Cerebral perfusion and intracranial pressure are influenced by the arterial partial pressure of CO2 and derangements might induce further brain damage. We investigated which lower and upper limits of prehospital end-tidal CO2 levels are associated with increased mortality in patients with severe traumatic brain injury.MethodsThe BRAIN-PROTECT study is an observational multicenter study. Patients with severe traumatic brain injury, treated by Dutch Helicopter Emergency Medical Services between February 2012 and December 2017, were included. Follow-up continued for 1 year after inclusion. End-tidal CO2 levels were measured during prehospital care and their association with 30-day mortality was analyzed with multivariable logistic regression.ResultsA total of 1776 patients were eligible for analysis. An L-shaped association between end-tidal CO2 levels and 30-day mortality was observed (p = 0.01), with a sharp increase in mortality with values below 35 mmHg. End-tidal CO2 values between 35 and 45 mmHg were associated with better survival rates compared to < 35 mmHg. No association between hypercapnia and mortality was observed. The odds ratio for the association between hypocapnia (< 35 mmHg) and mortality was 1.89 (95% CI 1.53–2.34, p < 0.001) and for hypercapnia (≥ 45 mmHg) 0.83 (0.62–1.11, p = 0.212).ConclusionA safe zone of 35–45 mmHg for end-tidal CO2 guidance seems reasonable during prehospital care. Particularly, end-tidal partial pressures of less than 35 mmHg were associated with a significantly increased mortality.

Association between intraoperative end-tidal carbon dioxide and postoperative organ dysfunction in major abdominal surgery: A cohort study.

Data on the effects of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative organ dysfunction are limited. Thus, this study was designed to investigate the relationship between the intraoperative EtCO2 level and postoperative organ dysfunction in patients who underwent major abdominal surgery under general anesthesia. We conducted a cohort study involving patients who underwent major abdominal surgery under general anesthesia at Kyoto University Hospital. We classified those with a mean EtCO2 of less than 35 mmHg as low EtCO2. The time effect was determined as the minutes when the EtCO2 value was below 35 mmHg, whereas the cumulative effect was evaluated by measuring the area below the 35-mmHg threshold. The outcome was postoperative organ dysfunction, defined as a composite of at least one organ dysfunction among acute renal injury, circulatory dysfunction, respiratory dysfunction, coagulation dysfunction, and liver dysfunction within 7 days after surgery. Of the 4,171 patients, 1,195 (28%) had low EtCO2, and 1,428 (34%) had postoperative organ dysfunction. An association was found between low EtCO2 and increased postoperative organ dysfunction (adjusted risk ratio, 1.11; 95% confidence interval [CI], 1.03-1.20; p = 0.006). Additionally, long-term exposure to EtCO2 values of less than 35 mmHg (≥224 min) was associated with postoperative organ dysfunction (adjusted risk ratio, 1.18; 95% CI, 1.06-1.32; p = 0.003) and low EtCO2 severity (area under the threshold) (adjusted risk ratio, 1.13; 95% CI, 1.02-1.26; p = 0.018). Intraoperative low EtCO2 of below 35 mmHg was associated with increased postoperative organ dysfunction.

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.

ROLE OF CAPNOGRAPHY IN SAFE SEDATION OF VITRECTOMY PATIENTS

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

Capnography as a tool for triaging and diagnosis of diabetic ketoacidosis in the emergency department: A prospective observational study.

The cornerstone of management of acidosis in a patient with diabetic ketoacidosis (DKA) has traditionally been carried out by blood gas analysis, which is expensive and associated with significant risk. It is against this background that the correlation between end-tidal carbon dioxide (EtCO2), blood pH, and EtCO2 bicarbonate levels was analyzed. The predictive value of EtCO2 was also analyzed in the diagnosis of DKA. Finally, we aimed to determine the value of EtCO2 as a screening test for the exclusion of DKA. This was a prospective cohort study carried out in the emergency department of a tertiary care teaching hospital from September 2020 to September 2021. Patients with suspected DKA underwent simultaneous blood gas collection and EtCO2 analysis. A total of 123 patients with blood sugar levels >250 mg/dl and moderate-to-large (≥2+) urine ketones were studied. A cut-off value of EtCO2 ≤24 was determined to rule in DKA with a sensitivity of 93.02% and specificity of 91.9%. EtCO2 >26 could effectively rule out the diagnosis of DKA with sensitivity of 98.8% and specificity of 75.7%. A significant linear correlation between pH and EtCO2 (P < 0.0001, r = 0.82) and HCO3 and EtCO2 (r = 0.896, P < 0.0001) was found. EtCO2 values ≤24 can accurately identify patients with DKA in the presence of elevated blood sugar and urinary ketones and must be considered a valuable addition to the diagnostic criteria. EtCO2 values >26 can be an effective triaging tool for ruling our DKA. A significant linear correlation between pH and EtCO2 and pH and HCO3 was observed. EtCO2 can be considered a surrogate marker for the degree of response to the treatment in DKA.

Augmented-Medication CardioPulmonary Resuscitation Trials in out-of-hospital cardiac arrest: a pilot randomized controlled trial

BackgroundPreviously conducted physician-centered trials on the usefulness of vasopressin have yielded negative results; thus, patient-oriented trials have been warranted. We hypothesize that Augmented-Medication CardioPulmonary Resuscitation could be helpful for selected patients with out-of-hospital cardiac arrest (OHCA).MethodsThis is a double-blind, single-center, randomized, placebo-controlled trial conducted in the emergency department in a tertiary, university-affiliated hospital in Seoul, Korea. A total of 148 adults with non-traumatic OHCA who had initial diastolic blood pressure (DBP) < 20 mm Hg via invasive arterial monitoring during the early cardiac compression period were randomly assigned to two groups. Patients received a dose of 40 IU of vasopressin or placebo with initial epinephrine. The primary endpoint was a sustained return of spontaneous circulation. Secondary endpoints were survival discharge, and neurologic outcomes at discharge.ResultsOf the 180 included patients, 32 were excluded, and 148 were enrolled in the trial. A sustained return of spontaneous circulation was achieved by 27 patients (36.5%) in the vasopressin group and 24 patients (32.4%) in the control group (risk difference, 4.1%; P = .60). Survival discharge and good neurologic outcomes did not differ between groups. The trial group had significantly higher median DBPs during resuscitation than the control group (16.0 vs. 14.5 mm Hg, P < 0.01). There was no difference in end-tidal carbon dioxide, acidosis, and lactate levels at baseline, 10 min, and end-time.ConclusionAmong patients with refractory vasodilatory shock in OHCA, administration of vasopressin, compared with placebo, did not significantly increase the likelihood of return of spontaneous circulation.

Abstract 216: Association Between Trajectories Of End-tidal Carbon Dioxide And Return Of Spontaneous Circulation Among Emergency Department Patients With Out-of-hospital Cardiac Arrest: A Retrospective Analysis Of A Prospective Registry

Introduction: The level of end-tidal carbon dioxide (EtCO 2 ) reflects the blood flow generated by cardiopulmonary resuscitation (CPR). Static EtCO 2 parameters, such as average EtCO 2 levels, has been reported to be associated with outcomes following out-of-hospital cardiac arrest (OHCA). Hypothesis: Distinct trajectories of EtCO 2 during CPR was associated with OHCA outcomes. Methods: This was a retrospective analysis of a prospectively collected database on patients with OHCA who had been resuscitated in the emergency department of a tertiary medical center between 2015 and 2020. Adult patients with ≥3 measurements of EtCO 2 were included. The primary outcome was the return of spontaneous circulation (ROSC). Group-based trajectory modelling was used to identify the EtCO 2 trajectories. Multivariable logistic regression analysis was performed to evaluate the association between EtCO 2 trajectories and ROSC. The predictive performance of the EtCO 2 trajectories was assessed using the area under the receiver operating characteristic curve (AUC). Results: The study comprised 655 patients with OHCA. In the primary analysis, three distinct EtCO 2 trajectories, including 10-mmHg, 30-mmHg, and 50-mmHg trajectories, were identified. Compared with the 10-mmHg trajectory, both 30-mmHg (odds ratio [OR]: 4.66, 95% confidence interval [CI]: 3.15-6.90) and 50-mmHg (OR: 7.58, 95% CI: 4.30-13.35) trajectories were associated with a higher likelihood of ROSC. In a sensitivity analysis of excluding EtCO 2 measured before tracheal intubation or after sodium bicarbonate administration, the predictive ability of the identified EtCO 2 trajectories remained. As a single predictor of ROSC, EtCO 2 trajectories had an acceptable discriminative performance (AUC: 0.69, 95% CI: 0.66-0.73). Conclusion: Three distinct EtCO 2 trajectories during CPR were identified and significantly associated with OHCA outcomes, which may assist in guiding the ongoing resuscitation efforts.

Augmented-Medication CardioPulmonary Resuscitation (AMCPR) trial: a study protocol for a randomized controlled trial.

Objective Clinical trials on demodynamic-directed cardiopulmonary resuscitation have been limited. The aim of this study is to investigate whether Augmented-Medication CardioPulmonary Resuscitation (AMCPR) would improve the odds of return of spontaneous circulation (ROSC) in patients with out-of-hospital cardiac arrest. Methods This is a double-blind, single-center, randomized placebo-controlled trial that will be conducted in the emergency department of a tertiary, university-affiliated hospital in Seoul, Korea. A total of 148 adult patients with nontraumatic, nonshockable, out-of-hospital cardiac arrest who have an initial diastolic blood pressure above 20 mmHg will be randomly assigned to two groups of 74 patients (a 1:1 ratio). Patients will receive an intravenous dose of 40 IU of vasopressin with epinephrine, or a placebo with epinephrine. The primary endpoint is a sustained ROSC (over 20 minutes). Secondary endpoints are enhanced diastolic blood pressure, end-tidal carbon dioxide levels, acidosis, and lactate levels during resuscitation. Discussion AMCPR is a trial about tailored medication for select patients during resuscitation. This is the first randomized control trial to identify patients who would benefit from vasopressin for achieving ROSC. This study will provide evidence about the effect of administration of vasopressin with epinephrine to increase ROSC rate. Trial registration ClinicalTrials.gov identifier: NCT03191240. Registered on June 19, 2017.

Obstructive sleep apnea is position dependent in young infants

BackgroundObstructive sleep apnea in infants with Pierre Robin sequence is sleep-position dependent. The influence of sleep position on obstructive events is not established in other infants.MethodsWe re-evaluated ten-year pediatric sleep center data in infants aged less than six months, with polysomnography performed in different sleep positions. We excluded infants with syndromes, genetic defects, or structural anomalies.ResultsComparison of breathing between supine and side sleeping positions was performed for 72 infants at the median corrected age of 4 weeks (interquartile range (IQR) 2-8 weeks). Of the infants, 74% were male, 35% were born prematurely, and 35% underwent study because of a life-threatening event or for being a SIDS sibling. Upper airway obstruction was more frequent (obstructive apnea-hypopnea index (OAHI), p < 0.001), 95th-percentile end-tidal carbon dioxide levels were higher (p = 0.004), and the work of breathing was heavier (p = 0.002) in the supine than in the side position. Median OAHI in the supine position was 8 h−1 (IQR 4–20 h−1), and in the side position was 4 h−1 (IQR 0-10 h−1).ConclusionsObstructive upper airway events in young infants are more frequent when supine than when sleeping on the side.ImpactThe effect of sleep position on obstructive sleep apnea is not well established in infants other than in those with Pierre Robin sequence.A tendency for upper airway obstruction is position dependent in most infants aged less than 6 months. Upper airway obstruction is more common, end-tidal carbon dioxide 95th-percentile values higher, and breathing more laborious in the supine than in the side-sleeping position.Upper airway obstruction and obstructive events have high REM sleep predominance.As part of obstructive sleep apnea treatment in young infants, side-sleeping positioning may prove useful.