Arterial Carbon Dioxide Levels Research Articles

Long-term mortality in patients with chronic obstructive pulmonary disease requiring acute non-invasive ventilation with and without obstructive sleep apnoea

IntroductionChronic obstructive pulmonary disease (COPD)/obstructive sleep apnoea (OSA) overlap syndrome (OVS) is associated with higher mortality compared with COPD alone in stable outpatients. However, the prognosis of patients hospitalised with...

Development and validation of a nomogram for predicting pulmonary complications in elderly patients undergoing thoracic surgery

BackgroundPostoperative pulmonary complications (PPCs) remain a prevalent concern among elderly patients undergoing surgery, with a notably higher incidence observed in elderly patients undergoing thoracic surgery. This study aimed to develop a nomogram to predict the risk of PPCs in this population.MethodsA total of 2963 elderly patients who underwent thoracic surgery were enrolled and randomly divided into a training cohort (80%, n = 2369) or a validation cohort (20%, n = 593). Univariate and multivariate logistic regression analyses were conducted to identify risk factors for PPCs, and a nomogram was developed based on the findings from the training cohort. The validation cohort was used to validate the model. The predictive accuracy of the model was evaluated by receiver operating characteristic (ROC) curve, area under ROC (AUC), calibration curve, and decision curve analysis (DCA).ResultsA total of 918 (31.0%) patients reported PPCs. Nine independent risk factors for PPCs were identified: preoperative presence of chronic obstructive pulmonary disease (COPD), elevated leukocyte count, higher partial pressure of arterial carbon dioxide (PaCO2) level, surgical site, thoracotomy, intraoperative hypotension, blood loss > 100 mL, surgery duration > 180 min, and malignant tumor. The AUC value for the training cohort was 0.739 (95% CI: 0.719–0.762), and it was 0.703 for the validation cohort (95% CI: 0.657–0.749). The P-values for the Hosmer-Lemeshow test were 0.633 and 0.144 for the training and validation cohorts, respectively, indicating a notable calibration curve fit. The DCA curve indicated that the nomogram could be applied clinically if the risk threshold was between 12% and 84%, which was found to be between 8% and 82% in the validation cohort.ConclusionThis study highlighted the pressing need for early detection of PPCs in elderly patients undergoing thoracic surgery. The nomogram exhibited promising predictive efficacy for PPCs in elderly patients undergoing thoracic surgery, enabling the identification of high-risk patients and consequently aiding in the implementation of preventive interventions.Graphical

Clinical study of prone positioning in invasive respiratory support for neonatal respiratory distress syndrome

To assess the effectiveness and safety of prone positioning in the treatment of neonatal respiratory distress syndrome (NRDS) using invasive respiratory support. A prospective study was conducted from June 2020 to September 2023 at Suining County People's Hospital, involving 77 preterm infants with gestational ages less than 35 weeks requiring invasive respiratory support for NRDS. The infants were randomly divided into a supine group (37 infants) and a prone group (40 infants). Infants in the prone group were ventilated in the prone position for 6 hours followed by 2 hours in the supine position, continuing in this cycle until weaning from the ventilator. The effectiveness and safety of the two approaches were compared. At 6 hours after enrollment, the prone group showed lower arterial blood carbon dioxide levels, inspired oxygen concentration, oxygenation index, rates of tracheal intubation bacterial colonization, and Neonatal Pain, Agitation and Sedation Scale scores compared to the supine group (P<0.05). There were no significant differences between the groups in terms of pH, arterial oxygen pressure, positive end-expiratory pressure, duration of mechanical ventilation, accidental extubation, ventilator-associated pneumonia, air leak syndrome, skin pressure sores, feeding intolerance, and grades II-IV intraventricular hemorrhage (P>0.05). Compared to supine positioning, prone ventilation effectively improves oxygenation, increases comfort, and reduces tracheal intubation bacterial colonization in neonates requiring mechanical ventilation for NRDS, without significantly increasing adverse reactions.

Analysis of the Long-Term Correlates Between Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease: A 10-Year Retrospective Study

Aim This study aims to assess the prevalence of overlap syndrome (OS) in Chronic Obstructive Pulmonary Disease (COPD) patients with Obstructive Sleep Apnea(OSA) symptoms undergoing polysomnography. We investigated the impact of hypoventilation and long-term oxygen therapy (LTOT) on the severity of OSA. Material and Methods We retrospectively reviewed COPD patients with OSA symptoms who underwent polysomnography from August 2012 to September 2022. The individuals' body mass index (BMI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), minimum and mean oxygen saturation values (minSpO2 and meanSpO2), sleep activities, REM period percentages (REM%), whether they used LTOT, and blood hematocrit levels and awake arterial carbon dioxide (PaCO2) levels were recorded. Results A total of 81 individuals with COPD were included in the study. The number of individuals with AHI&gt;5 was 76(93.9%). Participants included 9 with mild OSA, 24 with moderate OSA and 43 with severe OSA. The mean sleep efficiency was found to be %78.3. The mean value of REM% was 7.3. Sixteen of the patients (19.7%) were receiving LTOT. Sleep efficiency was statistically higher in the group using LTOT (p=0.048). AHI and ODI values were statistically higher in the group with high PaCO2 than in the group without (respectively; p=0.048, p=0.008). The mean values of min SpO2 and meanSpO2 were found to be lower in the group with high PaCO2 (p=0.013, p=0.008; respectively) Conclusion In OS participants, sleep efficiency is low, and having high PaCO2 is associated with lower minSpO2 and meanSpO2, higher ODI, and AHI. The use of LTOT increases sleep efficiency.

Effectiveness of Structured Teaching Programme on Knowledge Regarding Arterial Blood Gas Analysis among Nursing Students in Chitwan, Nepal A Pre-experimental One Group Pretest Post-test Design

Background: Arterial blood gas (ABG) analysis measures blood pH, oxygen (O2), and carbon dioxide (CO2) levels. Normal pH is 7.35-7.45, PaO2 ranges from 70-100 mm Hg, PaCO2 is 35-45 mm Hg, and SaO2 is 93-98%. HCO3 normal value is 22-26 meq/l. This study assesses the effectiveness of a structured teaching program on arterial blood gas analysis knowledge among nursing students. Methods: A pre-experimental study with a one-group pretest-posttest design evaluated the effectiveness of a structured teaching program on Arterial Blood Gas analysis knowledge among nursing students from two Purbanchal University-affiliated colleges. Narayani Samudayik Nursing College was chosen using a probability-based simple random sampling lottery method. Enumerative sampling was employed to select respondents for the study. Results: The study found that 87% of respondents initially had an average knowledge level of arterial blood gas analysis, with 13% having adequate knowledge. After intervention, 82.6% demonstrated adequate knowledge, and 17.4% maintained an average level. Mean knowledge scores significantly increased from 67.15 to 87.7 in pretest and posttest, respectively (p&lt;0.001). The results affirm the intervention's effectiveness in improving participants' understanding of arterial blood gas analysis..Conclusion: Most respondents had average knowledge of ABG analysis. Following the structured teaching program, the majority achieved adequate knowledge, demonstrating its significant positive impact in enhancing nursing students' unde standing of ABG analysis.

Intraoperative partial pressure of arterial carbon dioxide levels and adverse outcomes in patients undergoing lung transplantation

ObjectivePatients undergoing lung transplantation (LTx) often experience abnormal hypercapnia or hypocapnia. This study aimed to investigate the association between intraoperative PaCO2 and postoperative adverse outcomes in patients undergoing LTx. MethodsWe retrospectively reviewed the medical records of 151 patients undergoing LTx. Patients’ demographics, perioperative clinical factors, and pre- and intraoperative PaCO2 data after reperfusion were collected and analyzed. Based on the PaCO2 levels, patients were classified into three groups: hypocapnia (≤35 mmHg), normocapnia (35.1–55 mmHg), and hypercapnia (>55 mmHg). Univariate and multivariable logistic regressions were used to identify independent risk factors for postoperative composite adverse events and in-hospital mortality. ResultsIntraoperative hypercapnia occurred in 69 (45.7%) patients, and hypocapnia in 17 (11.2%). Patients with intraoperative PaCO2 of 35.1–45 mmHg showed a lower incidence of composite adverse events (53.3%) and mortality (6.2%) (P < 0.001). There was no significant difference in composite adverse events and mortality among preoperative PaCO2 groups (P > 0.05). Compared with intraoperative PaCO2 at 35.1–45 mmHg, the risk of composite adverse events in hypercapnia group increased: the adjusted OR was 3.07 (95% confidence interval [CI]: 1.36–6.94; P = 0.007). The risk of death was significantly higher in hypocapnia group than normocapnia group, the adjusted OR was 7.69 (95% CI: 1.68–35.24; P = 0.009). Over ascending ranges of PaCO2, PaCO2 at 55.1–65 mmHg had the strongest association with composite adverse events, the adjusted OR was 6.40 (95% CI: 1.18–34.65; P = 0.031). ConclusionThese results demonstrate that intraoperative hypercapnia independently predicts postoperative adverse outcomes in patients undergoing LTx. Intraoperative hypocapnia shows predictive value for postoperative in-hospital mortality in LTx.

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.

Pressure versus volume-controlled ventilation with BASKA mask airway in laparoscopic cholecystectomy: A randomized clinical study

ABSTRACT Background The best ventilation mode that suits with LMAs is still unclear. In this study, we investigated the ventilatory performance of Baska masks in patients who underwent elective laparoscopic cholecystectomy under general anaesthesia and pneumoperitoneum with either volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) mode. Methods Fifty-Six patients with ASA I – II, who underwent laparoscopic cholecystectomy, were randomly classified into VCV (n = 28) and PCV (n = 28) groups. The lung was ventilated with a tidal volume of 8 ml/kg in the VCV group. It was ventilated initially using an inflating pressure that delivered a tidal volume of 8 ml/kg with a maximum of 35 cmH2O in the PCV group. The primary outcome was the intraoperative oropharyngeal leak pressure (OLP) of the Baska mask. Secondary outcomes were intraoperative lung mechanics, arterial carbon dioxide levels, and perioperative adverse effects. Results After pneumoperitoneum inflation, the OLP, peak inflation pressure (PIP), mean pressure (Pmean), PaCO2, and end-tidal CO2 significantly increased, and the calculated dynamic compliance significantly decreased in both ventilation modes. All variables partially returned to baseline after pneumoperitoneum deflation. Patients ventilated with PCV mode demonstrated significantly lower PIP and PaCO2 levels but higher dynamic compliance with statistically comparable OLP-PIP difference and higher leak fraction. Conclusion In this study, Patients ventilated with PCV mode showed lower PIP and PaCO2 but higher dynamic compliance, and higher leak fraction. However, both modes investigated provided effective Baska mask ventilation and maintained the OLP throughout the procedure with a statistically comparable OLP-PIP difference.

Case Report of Malignant Hyperthermia in the Emergency Department.

Malignant hyperthermia (MH) is a rare but deadly condition that may be encountered in the emergency department (ED). This report highlights a case of a patient who initially presented for acute agitation with hypertension and tachycardia and provides explanation for how to manage MH. A 44-year-old male presented to the ED with altered mental status, eventually requiring intubation with etomidate and succinylcholine. Despite being afebrile initially, the patient developed a rectal temperature of 105.3° Fahrenheit (F) with significantly elevated arterial carbon dioxide levels after intubation. The treating team initiated cooling measures and dantrolene, leading to a positive outcome. Clinicians should strive for expeditious recognition of MH and treatment with an updated institutional protocol.

Transcutaneous carbon dioxide monitoring during prolonged apnoea with high-flow nasal oxygen.

The duration of apnoeic oxygenation with high-flow nasal oxygen is limited by hypercapnia and acidosis and monitoring of arterial carbon dioxide level is therefore essential. We have performed a study in patients undergoing prolonged apnoeic oxygenation where we monitored the progressive hypercapnia with transcutaneous carbon dioxide. In this paper, we compared the transcutaneous carbon dioxide level with arterial carbon dioxide tension. This is a secondary publication based on data from a study exploring the limits of apnoeic oxygenation. We compared transcutaneous carbon dioxide monitoring with arterial carbon dioxide tension using Bland-Altman analyses in anaesthetised and paralysed patients undergoing prolonged apnoeic oxygenation until a predefined limit of pH 7.15 or PCO2 of 12 kPa was reached. We included 35 patients with a median apnoea duration of 25 min. Mean pH was 7.14 and mean arterial carbon dioxide tension was 11.2kPa at the termination of apnoeic oxygenation. Transcutaneous carbon dioxide monitoring initially slightly underestimated the arterial tension but at carbon dioxide levels above 10kPa it overestimated the value. Bias ranged from -0.55 to 0.81 kPa with limits of agreement between -1.25 and 2.11 kPa. Transcutaneous carbon dioxide monitoring provided a clinically acceptable substitute for arterial blood gases but as hypercapnia developed to considerable levels, we observed overestimation at high carbon dioxide tensions in patients undergoing apnoeic oxygenation with high-flow nasal oxygen.

Clinical usefulness of end-tidal CO2 measured using a portable capnometer in patients with respiratory disease.

This study aimed to evaluate the correlation and agreement between end-tidal CO2 (EtCO2 ) measured with the novel portable capnometer (CapnoEye®) and partial pressure of arterial carbon dioxide (PaCO2 ) levels in patients with respiratory diseases and to compare the efficacy of EtCO2 and PvCO2 in predicting PaCO2 levels. We analyzed the correlation and the agreement between EtCO2 and PaCO2 and between PvCO2 and PaCO2 using Pearson's moment correlation coefficient in patients with type 1 and type 2 respiratory failure and both groups overall. A total of 100 samples were included that comprised 67 men (67%). The mean age of the subjects was 77 ± 13 years. Chronic obstructive pulmonary disease (COPD) (43%) was the most common disease. There was a high correlation between EtCO2 and PaCO2 (r = 0.88; p < 0.0001). Sixty-six PvCO2 samples were obtained, and there was a high correlation between PvCO2 and PaCO2 (r = 0.81; p < 0.0001). Regarding type 2 respiratory failure, there was a high correlation between EtCO2 and PaCO2 (r = 0.81). The Bland-Altman analysis between PaCO2 and EtCO2 revealed a bias of 5.7 mmHg, with limits of agreement ranging from -5.1 mmHg to 16.5 mmHg. In contrast, the analysis between PaCO2 and PvCO2 revealed a bias of -6.8 mmHg, and the limits of agreement ranged from -22.13 mmHg to 8.53 mmHg. EtCO2 measured by CapnoEye® was significantly correlated to PaCO2 levels in patients with respiratory diseases. Moreover, CapnoEye® may be more useful for predicting hypercapnia conditions in which respiratory diseases are compared with measure PvCO2 .

Ventilation during continuous compressions or at 30:2 compression-to-ventilation ratio results in similar arterial oxygen and carbon dioxide levels in an experimental model of prolonged cardiac arrest

BackgroundIn refractory out-of-hospital cardiac arrest, transportation to hospital with continuous chest compressions (CCC) from a chest compression device and ventilation with 100% oxygen through an advanced airway is common practice. Despite this, many patients are hypoxic and hypercapnic on arrival, possibly related to suboptimal ventilation due to the counterpressure caused by the CCC. We hypothesized that a compression/ventilation ratio of 30:2 would provide better ventilation and gas exchange compared to asynchronous CCC during prolonged experimental cardiopulmonary resuscitation (CPR).MethodsWe randomized 30 anaesthetized domestic swine (weight approximately 50 kg) with electrically induced ventricular fibrillation to the CCC or 30:2 group and bag-valve ventilation with a fraction of inspired oxygen (FiO2) of 100%. We started CPR after a 5-min no-flow period and continued until 40 min from the induction of ventricular fibrillation. Chest compressions were performed with a Stryker Medical LUCAS® 2 mechanical chest compression device. We collected arterial blood gas samples every 5 min during the CPR, measured ventilation distribution during the CPR using electrical impedance tomography (EIT) and analysed post-mortem computed tomography (CT) scans for differences in lung aeration status.ResultsThe median (interquartile range [IQR]) partial pressure of oxygen (PaO2) at 30 min was 110 (52–117) mmHg for the 30:2 group and 70 (40–171) mmHg for the CCC group. The median (IQR) partial pressure of carbon dioxide (PaCO2) at 30 min was 70 (45–85) mmHg for the 30:2 group and 68 (42–84) mmHg for the CCC group. No statistically significant differences between the groups in PaO2 (p = 0.40), PaCO2 (p = 0.79), lactate (p = 0.37), mean arterial pressure (MAP) (p = 0.47) or EtCO2 (p = 0.19) analysed with a linear mixed model were found. We found a deteriorating trend in PaO2, EtCO2 and MAP and rising PaCO2 and lactate levels through the intervention. There were no differences between the groups in the distribution of ventilation in the EIT data or the post-mortem CT findings.ConclusionsThe 30:2 and CCC protocols resulted in similar gas exchange and lung pathology in an experimental prolonged mechanical CPR model.

The Effect of Switching from Volume-Controlled to Pressure-Controlled Ventilation on Respiratory Distress and Asynchrony Index Improvement among Mechanically Ventilated Adults.

It is important to synchrony the time, intensity, and respiratory signal of the phrenic nerve between the patient and the ventilator. This study aimed to evaluate the effect of switching from volume-controlled to pressure-controlled ventilation on respiratory distress and asynchrony index improvement. In this randomized controlled clinical trial, 70 patients admitted to the intensive care unit under mechanical ventilation were included. Asynchronous evaluation was performed by examining the patient and evaluating and analyzing the graphic flow curve and ventilator pressure, which included trigger and flow asynchronous and asynchronous cycling. In the intervention group, the mode of ventilation was switched to PSIMV such that peak inspiratory pressures would be equivalent to positive end-expiratory pressure (PEEP) in the volume-controlled mode. Finally, again at 60, 75, and 90 min, information about the ventilator and the patient's symptoms, and arterial carbon dioxide levels were sent by arterial gas sample. The asynchronous index was also recorded in both groups. This study showed that the mean of variables such as height, ideal body weight, tidal volume, set rate; Sense, FiO2, PEEP did not differ significantly between the two groups. The mean of asynchrony was significantly reduced in both control group (16.51 ± 3.35-14.51 ± 2.90; P < 0.001) and intervention group (18.26 ± 6.13-13.32 ± 5.53; P < 0.001). Regardless of the type and severity of the disease, switching the ventilation mode from volume-controlled to pressure-controlled can improve patient adaptation to the ventilator, especially in cases with frequent asynchrony.

Volume-Controlled, Pressure-Controlled vs. Pressure-Controlled Volume-Guaranteed Ventilations in Improving Respiratory Dynamics During Laparoscopic Cholecystectomy

Introduction: Pressure-controlled volume-guaranteed (PCV-VG) mode has the advantage of both volume-controlled (VCV) and pressure-controlled ventilation (PCV). Our objective is to compare gaseous exchange and lung dynamic compliance (C dyn) after pneumoperitoneum and just before desufflation in VCV, PCV, and PCV-VG mode in laparoscopic cholecystectomy (LC). Materials and Methods: A total of 105 patients undergoing LC under general anesthesia were randomly distributed to group V (received VCV), group P (PCV), and group PV (PCV-VG) as mode of ventilation. Two arterial blood samples were taken for blood gas analysis: after the pneumoperitoneum (T1) and right before abdominal desufflation (T2). Arterial partial oxygen pressure (PaO2) and carbon dioxide (PaCO2) levels, oxygen saturation (SpO2) and end-tidal carbon dioxide were compared at these two points of time between the groups. Results: C dyn was higher in group P (43.21 ± 4.4 mL/cmH2O) compared with group V (39.18 ± 3.2 mL/cmH2O) and PV (40.37 ± 2.45 mL/cmH2O) at T2 (P &lt; 0.001). PaO2 was significantly higher (P &lt; 0.001) in group P (197.50 ± 17.29 mm Hg) at T2 compared with group V (178.90 ± 23.7 mm Hg) and PV (183.47 ± 22.99 mm Hg). Furthermore, PaCO2 was also significantly higher in Group P (40.19 ± 2.92 mm Hg) compared with group V (32.57 ± 2.09 mm Hg) and group PV (34.14 ± 3.27 mm Hg). Conclusion: PaO2 and dynamic compliance are higher in pressure-controlled mode but, high PaCO2 in pressure-controlled mode indicates inadequate ventilation. Therefore, pressure controlled volume guaranteed mode can be considered as a favorable ventilation strategy during LC because dynamic compliance and PaO2 are higher than volume controlled ventilation and PaCO2 is significantly less than pressure controlled mode.

CVR-MRICloud: An online processing tool for CO2-inhalation and resting-state cerebrovascular reactivity (CVR) MRI data.

Cerebrovascular Reactivity (CVR) provides an assessment of the brain's vascular reserve and has been postulated to be a sensitive marker in cerebrovascular diseases. MRI-based CVR measurement typically employs alterations in arterial carbon dioxide (CO2) level while continuously acquiring Blood-Oxygenation-Level-Dependent (BOLD) images. CO2-inhalation and resting-state methods are two commonly used approaches for CVR MRI. However, processing of CVR MRI data often requires special expertise and may become an obstacle in broad utilization of this promising technique. The aim of this work was to develop CVR-MRICloud, a cloud-based CVR processing pipeline, to enable automated processing of CVR MRI data. The CVR-MRICloud consists of several major steps including extraction of end-tidal CO2 (EtCO2) curve from raw CO2 recording, alignment of EtCO2 curve with BOLD time course, computation of CVR value on a whole-brain, regional, and voxel-wise basis. The pipeline also includes standard BOLD image processing steps such as motion correction, registration between functional and anatomic images, and transformation of the CVR images to canonical space. This paper describes these algorithms and demonstrates the performance of the CVR-MRICloud in lifespan healthy subjects and patients with clinical conditions such as stroke, brain tumor, and Moyamoya disease. CVR-MRICloud has potential to be used as a data processing tool for a variety of basic science and clinical applications.

Retrospective Analysis of Arterial Carbon Dioxide Level and Arterial pH Level at the Time of Initiation of Respiratory ECMO and Outcome

AbstractIntroduction Respiratory extracorporeal membrane oxygenation (ECMO) is well established and its popularity has increased during coronavirus disease 2019 (COVID-19) time. The efficacy of ECMO has been proved in refractory respiratory failure with varied etiology. More than 85,000 respiratory ECMO cases (neonatal, pediatric, adult) registered as per Extracorporeal Life support Organization (ELSO) statistics April 2022 report, with survived to discharge or transfer ranging from 58 to 73%. Early initiation of ECMO is usually associated with shorter ECMO run and better outcome. Many patient factors have been associated with mortality while on ECMO. Pre-ECMO patient pH and arterial partial pressure of carbon dioxide (paCO2) have been associated with poor outcome. We designed a retrospective study from a single tertiary care center and analyzed our data of all respiratory ECMO (neonatal, pediatric, and adult) to understand the effect of pre ECMO, paCO2, and arterial pH to ECMO outcome.Methods It is a retrospective analysis of data collected of patients with acute respiratory failure managed on ECMO from January 2010 to December 2021. Pre-ECMO (1–6 hours before initiation), paCO2, and arterial pH level were noted and analyzed with primary and secondary outcome. Primary outcome goal was survivor and discharged home versus nonsurvivor, while secondary goal was the number of ECMO days and incidence of neurological complications. The statistical analysis was done for primary outcome and incidences of neurological complications and p-value obtained by using chi-squared method. Meta-analysis was done by classifying the respiratory ECMO cases in three major category—COVID-19, H1N1 non-COVID-19, and H1N1 respiratory failure.Results The total 256 patients of respiratory failure were treated with ECMO during specified period by Riddhi Vinayak Multispecialty Hospital ECMO team. Data analysis of 251 patients (5 patients were transferred for lung transplant, hence been not included in study) done. Patients were divided on the basis of pH level less than 7.2 and more than 7.2 and analyzed for primary and secondary outcome. Similarly, patients were divided on the basis of paCO2 level of less than 45 and more than 45.Patient with pre-ECMO pH level more than 7.2 has statistically better survived extracorporeal life support (ECLS) (p-value: 0.008) and survival to discharge home (p-value: 0.038) chances. Pre-ECMO paCO2 level of less than 45 also showed better survival chance of survived ECLS (46.67 vs. 36.02) and survived to discharge home (42.22 vs. 31.06) but not statistically significant (p-value: 0.15 and 0.18, respectively). There was no significant difference in average number of ECMO days in patient survived to discharge home with paCO2 less than 45 and more than 45 (15.7 vs. 11.1 days), and also in pH more than 7.2 and pH less than 7.2 (15.8 vs. 11.6). The incidence of neurological complications was also found lower in patient with pH more than 7.2 (7.5 vs. 17.3%, p-value: 0.034) and in paCO2 level of less than 45 (4.4 vs. 12.65, p-value: 0.15).Conclusion Pre-ECMO arterial pH of more than 7.2 (statistically significant) and paCO2 of less than 45 (statistically not significant) have definitely better survival chances and have lesser incidences of neurological complications. There was no significance difference in the number of ECMO days in either group. Authors recommends early initiation of ECMO for mortality and morbidity benefits.

Risk factors of tracheal extubation failure in children with spinal muscular atrophy combined with pneumonia

Objective: To summarize the risk factors of tracheal extubation failure in children with spinal muscular atrophy (SMA) combined with pneumonia. Methods: In this retrospective study, clinical data of 34 children with SMA combined with pneumonia who were hospitalized in Children's Hospital Affiliated to Capital Institute of Pediatrics from August 2018 to December 2021 were analyzed. According to whether the extubation was successful or not, they were divided into the success group and the failure group. The risk factors that may affect the success of extubation between two groups were derived by comparing the clinical characteristics by Mann-Whitney U test and Chi-square test, followed by multivariate Logistic regression. Results: Among the 34 cases, there were 14 males and 20 females, aged 10.8 (6.0,25.2) months at the time of hospitalization, 31 cases were type 1 SMA and 3 cases were type 2. Eleven children were unable to eat independently before intubation, 22 were treated with airway clearance techniques and 28 had multiple pulmonary infections. There were 21 cases in the success group and 13 cases in the failure group. The failure group had higher maximum partial pressure of arterial carbon dioxide level during intubation and higher rate of consolidation changes in chest images before extubation (81 (49,86) vs. 48 (43,56) mmHg (1 mmHg=0.133 kPa), 6/13 vs. 10%(2/21), Z=-2.55, χ2=5.99, both P<0.05). Multivariate Logistic regression analysis showed that tube feeding before intubation (OR =39.88, 95%CI 3.36-473.29, P=0.003) and not receiving airway clearance therapy (OR =14.55, 95%CI 1.35-156.78, P=0.027) were independent risk factors for extubation failure. Conclusions: The independent risk factors of tracheal extubation failure in children with SMA combined with pneumonia are unable to eat independently before intubation and not receiving airway clearance therapy. Therefore, the conditions to improve the success of extubation consist of having the ability to eat independently before intubation, using airway clearance techniques to improve ventilation and to make the chest images as clear as possible.

Respiratory Drive in Patients with Sepsis and Septic Shock: Modulation by High-flow Nasal Cannula.

Experimental and pilot clinical data suggest that spontaneously breathing patients with sepsis and septic shock may present increased respiratory drive and effort, even in the absence of pulmonary infection. The study hypothesis was that respiratory drive and effort may be increased in septic patients and correlated with extrapulmonary determinant and that high-flow nasal cannula may modulate drive and effort. Twenty-five nonintubated patients with extrapulmonary sepsis or septic shock were enrolled. Each patient underwent three consecutive steps: low-flow oxygen at baseline, high-flow nasal cannula, and then low-flow oxygen again. Arterial blood gases, esophageal pressure, and electrical impedance tomography data were recorded toward the end of each step. Respiratory effort was measured as the negative swing of esophageal pressure (ΔPes); drive was quantified as the change in esophageal pressure during the first 500 ms from start of inspiration (P0.5). Dynamic lung compliance was calculated as the tidal volume measured by electrical impedance tomography, divided by ΔPes. The results are presented as medians [25th to 75th percentile]. Thirteen patients (52%) were in septic shock. The Sequential Organ Failure Assessment score was 5 [4 to 9]. During low-flow oxygen at baseline, respiratory drive and effort were elevated and significantly correlated with arterial lactate (r = 0.46, P = 0.034) and inversely with dynamic lung compliance (r = -0.735, P < 0.001). Noninvasive support by high-flow nasal cannula induced a significant decrease of respiratory drive (P0.5: 6.0 [4.4 to 9.0] vs. 4.3 [3.5 to 6.6] vs. 6.6 [4.9 to 10.7] cm H2O, P < 0.001) and effort (ΔPes: 8.0 [6.0 to 11.5] vs. 5.5 [4.5 to 8.0] vs. 7.5 [6.0 to 12.6] cm H2O, P < 0.001). Oxygenation and arterial carbon dioxide levels remained stable during all study phases. Patients with sepsis and septic shock of extrapulmonary origin present elevated respiratory drive and effort, which can be effectively reduced by high-flow nasal cannula.

End-tidal carbon dioxide measurements as a surrogate to arterial carbon dioxide during pediatric laparoscopic surgeries: a prospective observational cohort study

BackgroundMaintaining normocapnia during mechanical ventilation in anesthetized children during laparoscopic surgeries is highly recommended. There is a debate regarding the use of capnography (ETCO2) as a trend monitor for evaluation of arterial carbon dioxide levels (PaCO2). We analyzed the relationship between ETCO2 and PaCO2 with time in elective pediatric laparoscopic surgeries. MethodsThis study was a prospective observational cohort analysis of 116 paired comparisons between PaCO2 and ETCO2 computed from 29 children (ASA I, 12...72 months). Arterial blood samples were withdrawn before, at 15...minutes and 30...minutes during pneumoperitoneum and 1...minute after deflation. ETCO2 value was recorded simultaneously, while arterial blood was withdrawn. PaCO2...ETCO2 relationship was evaluated by Pearson's correlation coefficients and Bland Altman Method of agreement. ResultsOut of the 116 comparisons analyzed, a PaCO2...ETCO2 difference beyond 0 to ..± 5...mmHg was recorded in 71 comparisons (61.2%) with negative difference in 34 comparisons (29.3%). A positive significant correlation between PaCO2 and ETCO2 was recorded before (r...=...0.617, p...=...0.000) and at 15...minutes (r...=...0.582, p...=...0.001), with no significant correlation at 30 minutes (r...=...0.142, p...=...0.461), either after deflation (r...=...0.108, p...=...0.577). Bland-Altman plots showed agreement between ETCO2 and PaCO2 before inflation with mean PaCO2-ETCO2 difference 0.14........5.6...mmHg (limits of 95% agreement -10.84...11.2, simple linear regression testing p-value 0.971), with no agreement at 15...minutes (0.51........7.15, -13.5...14.5, p...=...0.000), 30...minutes. (2.62........7.83, -12.73...17.97, p...=...0.000), or after deflation (1.81........6.56, -10.93...14.55, p...=...0.015). ConclusionUsage of capnography as a trend monitor in pediatric laparoscopic surgeries may not be a reliable surrogate for PaCO2 levels. Trial registrationClinical Trials. gov (Identifier: NCT03361657)

Sleep increases leaks and asynchronies during home noninvasive ventilation: a polysomnographic study.

In patients treated with noninvasive ventilation, sleep-related breathing changes can modify patient-ventilator interactions, which could reduce its effectiveness. The aim of this prospective observational study was to determine the impact of sleep/wake state on leaks, upper airway obstructive events, and asynchronies in patients treated by long-term noninvasive ventilation. Stable patients adapted to noninvasive ventilation were considered for nocturnal polysomnography. Unintentional leaks, upper airway obstructive events, and asynchronies were compared between sleep and awake periods. Twenty-eight patients were enrolled. Underlying diagnoses were neuromuscular disease (n = 11), chest wall disease (n = 8), and obesity-hypoventilation (n = 9). Leaks were more frequent in sleep than in awake periods, with a median of 10% (interquartile range [IQR], 0%-75%) vs 1% (IQR, 0%-9%) of time (P < .001), respectively. During sleep, asynchronies with and without associated leak affected 27% of breaths (IQR, 16%-39%) compared with non-leak-related asynchronies that were recorded in 8% (IQR, 3%-25%) of breaths (P < .001). Asynchronies affecting more than 10% of total breaths were more frequent in sleep (25 patients, 89%) than in awake time (8 patients, 29%; P = .25). Eleven patients (39%) presented with 5 or more upper airway obstructive events without reduction in ventilatory drive per hour of sleep. In patients adapted to home noninvasive ventilation, leaks, asynchronies, and upper airway obstructive events are frequent during the night and are concentrated in sleep periods. Asynchronies are often associated with leaks. These findings may have clinical implications considering that in patients with low sleep efficiency respiratory events could be underestimated if sleep is not evaluated. Martí S, Ferré A, Sampol G, etal. Sleep increases leaks and asynchronies during home noninvasive ventilation: a polysomnographic study. J Clin Sleep Med. 2022;18(1):225-233.