Arterial Carbon Dioxide Pressure Research Articles

Effects of General Anesthesia on the Results of Cardiac Catheterization in Pediatric Patients with Ventricular Septal Defect

<b>Background:</b> There is no gold standard sedation method for pediatric cardiac catheterization. In congenital heart diseases with intracardiac shunts, hemodynamic parameters are prone to change depending on the ventilation conditions and anesthetics, although few studies have examined these effects. The purpose of this study was to investigate the effects of two different sedation methods on the hemodynamic parameters. <b>Methods:</b> This study retrospectively evaluated consecutive patients with ventricular septal defect (VSD) below 1 year of age who underwent cardiac catheterization at Aichi Children’s Health and Medical Center, who were divided into age- and VSD diameter-matched general anesthesia (GA) and monitored anesthesia care (MAC) under the natural airway groups (<i></i>n = 40 each), for comparison of hemodynamic parameters. <b>Results:</b> In the GA group, arterial blood pH and arterial partial pressure of oxygen were significantly higher (<i>p</i> < 0.01), whereas arterial partial pressure of carbon dioxide was significantly lower than in the MAC group (<i>p</i> < 0.01). Mean pulmonary artery pressure (<i>p</i> < 0.05) and systemic blood pressure (<i>p</i> < 0.01) were lower in the GA group. Pulmonary vascular resistance index (<i>p</i> < 0.01) and systemic vascular resistance index (<i>p</i> < 0.01) were also significantly lower in the GA group than the MAC group. There were no significant differences in pulmonary blood flow index, systemic blood flow index, and pulmonary/systemic blood flow ratio between the two groups. <b>Conclusions:</b> Cardiac catheterization under GA in VSD patients results in different hemodynamic parameters compared to that under MAC. In particular, when using pulmonary artery pressure and pulmonary vascular resistance measured under GA for judgment regarding the surgical indications or perioperative management, consideration should be given to the fact that these parameters might be lower compared to those measured under MAC.

970: PHYSIOLOGY-BASED VENTILATOR COMPUTER DECISION SUPPORT OUTPERFORMS CLINICIANS IN AN IN SILICO TRIAL

Introduction: Intensivists are routinely required to titrate alveolar minute ventilation based on blood gas information. Survey data show that intensive care trainees feel insufficiently trained in ventilator management. Bedside decision support has the potential to facilitate more efficient ventilator titration and serve as a teaching tool for trainees. Methods: We developed an online ventilator calculator based upon arterial partial pressure of carbon dioxide (PaCO2) and Henderson-Hasselbalch equations, allowing clinicians to input ventilator parameters as well as current and desired blood gas information. We validated predictions among arterial blood gas (ABG) values from a single quaternary academic pediatric intensive care unit (PICU). We included all ABG values obtained between 1/1/2010 and 12/31/2020 among PICU patients receiving invasive pressure control, volume control, or volume targeted ventilation and concurrent pharmacologic muscle relaxation with a repeat blood gas analysis within 1-24 hours. We excluded ABGs from patients on extracorporeal support. We subsequently performed a retrospective in-silico trial on a subset of ABGs meeting criteria for ventilator weaning (pCO2 < 30 and pH > 7.35 or pCO2 < 50 and pH > 7.50) or escalation (pCO2 > 50 and pH < 7.30 or pCO2 > 45 and pH < 7.20), excluding patients with traumatic brain injury. Clinician behavior was compared against calculator recommendations, with a goal of achieving an ABG value that met neither weaning nor escalation criteria. Results: There were 16,835 included ABGs among 664 patients, with a median (IQR) time between ABGs of 3.8 (2.2-4.4) hours. The median (IQR) difference between predicted and actual PaCO2 values was 0.00 (-3.06-3.00) mmHg. 11,460/16,835 (68.1%) PaCO2 values were within 5 mmHg of predicted, and 14,902/16,835 (88.5%) were within 10 mmHg. There were 2,433 ABGs among 350 patients included in the in-silico trial. Calculator recommendations were preferable to clinician behavior in 1,149/1,534 (74.9%) weaning scenarios and 605/899 (67.3%) escalation scenarios. Conclusions: Computer decision support outperformed clinician actions in this retrospective in-silico trial and may provide a useful teaching tool for trainees. Prospective study is needed to determine feasibility and user satisfaction.

Effects of Retroperitoneal or Transperitoneal Pneumoperitoneum on Inferior Vena Cava Hemodynamics and Cardiopulmonary Function: A Prospective Real-Time Comparison.

Objective: To evaluate the effects of CO2 pneumoperitoneum on venous hemodynamics and cardiopulmonary function during transperitoneal or retroperitoneal laparoscopic surgery. Materials and Methods: A single-institution prospective study. Forty-three patients with renal-cell carcinoma undergoing retroperitoneal (22) or transperitoneal (21) laparoscopic partial nephrectomy were enrolled. Hemodynamic functions were monitored by minimally invasive FloTrac/Vigileo system. Transesophageal echocardiography was used to measure the diameter and blood flow of the inferior vena cava (IVC). Measured parameters were recorded at baseline, 10, 30, 60 minutes following insufflation to 14 mm Hg and 10 minutes following desufflation. Results: For hemodynamic changes in the transperitoneal laparoscopic surgery (TPL) and retroperitoneal laparoscopic surgery (RPL), transperitoneal CO2 insufflation resulted in a rapid parallel increase in central intravenous pressure (CVP), peak airway pressure (AWP), and IVC blood flow velocity after the first 30 minutes of pneumoperitoneum (p < 0.05). In contrast, CVP, AWP, and IVC blood flow velocity increased progressively in RPL. The variation of those parameters was significantly lower than that of TRL (p < 0.001; p = 0.002; p = 0.004). The mean maximum CVP in the two groups was 20 and 16 mm Hg, respectively. The IVC diameter at the cavoatrial junction was significantly reduced in TPL after 10 minutes of insufflation, but it remained unchanged in RPL throughout the surgery. For cardiopulmonary function changes, heart output decreased after a short period of pneumoperitoneum, but no statistical differences were observed between the two groups. The increments of partial pressure of arterial carbon dioxide and end-tidal carbon dioxide tension were significantly higher in RPL than TPL (p < 0.001; p < 0.001). Conclusions: Compared with retroperitoneal pneumoperitoneum, transperitoneal pneumoperitoneum has significant effects on IVC hemodynamics. Elevated intra-abdominal pressure (IAP) causes higher AWP and venous return resistance, which lead to the significant increase of CVP during transperitoneal approach. Adjusting the balance between IAP and CVP might be an effective way to control intravenous bleeding. Clinical Trial Registry: Registration number: ChiCTR2000038291.

Tests and Indices Predicting Extubation Failure in Children: A Systematic Review and Meta-analysis.

There is lack of consensus on what constitutes best practice when assessing extubation readiness in children. This systematic review aims to synthesize data from existing literature on pre-extubation assessments and evaluate their diagnostic accuracies in predicting extubation failure (EF) in children. A systematic search in PubMed, EMBASE, Web of Science, CINAHL, and Cochrane was performed from inception of each database to 15 July 2021. Randomized controlled trials or observational studies that studied the association between pre-extubation assessments and extubation outcome in the pediatric intensive care unit population were included. Meta-analysis was performed for studies that report diagnostic tests results of a combination of parameters. In total, 41 of 11,663 publications screened were included (total patients, n = 8111). Definition of EF across studies was heterogeneous. Fifty-five unique pre-extubation assessments were identified. Parameters most studied were: respiratory rate (RR) (13/41, n = 1945), partial pressure of arterial carbon dioxide (10/41, n = 1379), tidal volume (13/41, n = 1945), rapid shallow breathing index (RBSI) (9/41, n = 1400), and spontaneous breathing trials (SBT) (13/41, n = 5652). Meta-analysis shows that RSBI, compliance rate oxygenation pressure (CROP) index, and SBT had sensitivities ranging from 0.14 to 0.57. CROP index had the highest sensitivity [0.57, 95% confidence interval (CI) 0.4-0.73] and area under curve (AUC, 0.98). SBT had the highest specificity (0.93, 95% CI 0.92-0.94). Pre-extubation assessments studied thus far remain poor predictors of EF. CROP index, having the highest AUC, should be further explored as a predictor of EF. Standardizing the EF definition will allow better comparison of pre-extubation assessments.

Effects of intra-operative fluid management under the guidance of stroke volume variability on short-term prognosis after thoracoscopic lobectomy.

We aimed to explore the influence of intra-operative fluid management under the guidance of stroke volume variability (SVV) on the short-term prognosis after thoracoscopic lobectomy. A total of 171 eligible patients from April 2017 to April 2019 were selected. All patients received intra-operative fluid management under the guidance of SVV, and were divided into low-, middle- and high-level groups (n = 57) using a random-numbers table. The general data, respiratory function indices at different time points, haemodynamic indices at different time points, use of vasoactive drugs, short-term prognosis indices and incidence of complications were compared. There were no significant differences in age, gender, operation time, one-lung ventilation time, amount of bleeding, arterial partial pressure of oxygen, arterial partial pressure of carbon dioxide, lung compliance and peak airway pressure at different time points, usage amount of anisodamine and incidence rate of complications among the three groups. In the low-level group, the fluid infusion amount and urine volume were significantly larger, the forced expiratory volume in one second (FEV1), percentage of FEV1 in the predicted value (FEV1%pred) and FEV1/forced vital capacity (FEV1/FVC) seven days after operation were higher, and the six-minute walk test (6MWT) distance was longer than those in the other two groups. The usage amount of dopamine, norepinephrine and esmolol was smaller, and the postoperative exhaust time was shorter than those in the other two groups. The low-level group had a smaller usage amount of isosorbide dinitrate injection and shorter length of postoperative hospital stay than the high-level group. Stroke volume had a significant difference at T2 and T3 in the low-level group, central venous pressure (CVP) and stroke volume had significant differences at T2 and T3 in the middle-level group, and heart rate (HR), mean arterial pressure and CVP were significantly different at T2 and T3 in the high-level group. Fluid management under the guidance of low-level SVV (8% ≤ SVV ≤ 9%) was conducive to the maintenance of stable haemodynamics in patients during thoracoscopic lobectomy, thereby improving short-term prognosis.

Altered blood gas tensions of oxygen and carbon dioxide confound coronary reactivity to apnea

PurposeArterial blood gases change frequently during anesthesia and intensive care. Apnea can occur during diagnostic exams and airway and surgical interventions. While the impact of blood gas levels on coronary blood flow is established, their confounding effect on coronary vasoreactivity in response to an apneic stimulus, especially in coronary artery disease, is not known.MethodsSix anesthetized control swine and eleven swine with coronary artery stenosis were examined. Nine different blood gas levels from a combination of arterial partial pressure of oxygen (70, 100, and 300 mmHg) and carbon dioxide (30, 40, and 50 mmHg) were targeted. Apnea was induced by halting controlled positive pressure ventilation for 3–30s, while the left descending coronary artery flow was measured and reported relative to apnea duration, and at the adjusted mean (12s).ResultsAt normoxemic-normocapnic blood gas levels, apnea increased coronary blood flow in proportion to the duration of apnea in the control (r = 0.533, p &amp;lt; 0.001) and stenosed groups (r = 0.566, p &amp;lt; 0.001). This culminated in a 42% (95% CI: 27–58) increase in controls (p &amp;lt; 0.001) and, to a lesser extent, 27% (15–40) in the presence of coronary artery stenosis (p &amp;lt; 0.001). Vasoreactivity was augmented by mild-hypoxemic levels [81% (65–97), and 66% (53–79) increase in flow respectively, p &amp;lt; 0.001 vs. normoxemia], but markedly reduced during hyperoxia (7.5% (−8.2–23) and 0.3% (−12–13), respectively, p &amp;lt; 0.001 vs. normoxemia).ConclusionAlterations of blood oxygen and carbon dioxide affect coronary vascular reactivity induced by apnea in swine, which was attenuated further in the presence of coronary stenosis. Especially hyperoxia significantly reduces coronary blood flow and blunts coronary vascular reactivity.

Detection of increased intracranial pressure in trans-oral robotic thyroidectomy using optic nerve sheath diameter measurement.

During transoral robot-assisted thyroidectomy, there is a risk of increasing intracranial pressure because the site of CO2 insufflation is narrow and close to the brain. We analyzed the pre- to post-CO2 neck insufflation change in the optic nerve sheath diameter during transoral robot-assisted thyroidectomy. Changes in vital-signs, airway pressure, and arterial carbon dioxide pressure were analyzed along with postoperative complications. Among the 30 participants, the post-CO2 inflation mean optic nerve sheath diameter (5.64 ± 0.54 mm) was higher than the pre-induction diameter (4.81 ± 0.37 mm) with a mean difference of 0.83 (95% CI, 0.69-0.97; p < 0.001), but returned to baseline after CO2 deflation in most cases. One participant had sustained increased optic nerve sheath diameter (6.35 mm) associated with severe new-onset postoperative headache. Transient elevation in the intracranial pressure during low-pressure CO2 neck insufflation in the transoral robot-assisted thyroidectomy did not appear to adversely affect patients.

Efficacy and safety of remifentanil dose titration to correct the spontaneous hyperventilation in aneurysmal subarachnoid haemorrhage: protocol and statistical analysis for a prospective physiological study

IntroductionSpontaneous hyperventilation (SHV) is common in aneurysmal subarachnoid haemorrhage (aSAH). The reduction in arterial partial pressure of carbon dioxide (PaCO2) may change the brain physiology, such as haemodynamics, oxygenation, metabolism...

An observational study of the effects of smoking cessation earlier on the clinical characteristics and course of acute exacerbations of chronic obstructive pulmonary disease

BackgroundPrevious studies have focused on the negative effects of continued smoking on chronic obstructive pulmonary disease (COPD). However, few studies have investigated the positive effects of long-term smoking cessation on patients suffering from acute exacerbations of COPD.MethodsThe study recruited and followed current or former smokers who had been hospitalized and diagnosed with AECOPD. An in-depth analysis of clinical and laboratory indicators was conducted.Results125 patients were covered, including 72 short-term quitters and 53 long-term quitters. The results showed that long-term smoking cessation may result in milder dyspnea and cough, a higher oxygenation index, a lower arterial partial pressure of carbon dioxide, and milder pulmonary hypertension, airflow restriction, and gas retention in patients with AECOPD. However, despite the lower treatment intensity for long-term quitters, improvement in dyspnea and an increase in oxygenation index were comparable to those achieved by short-term quitters. Furthermore, patients with mild phlegm, which accounted for 84% of all subjects, showed greater improvement in phlegm in AECOPD patients with long-term cessation of smoking.ConclusionIt was found that in patients with AECOPD who quit smoking for a long period of time, there was a reduction in symptoms, improvement in lung function, reduction in treatment intensity, and better improvement in phlegm symptoms after therapy. It is beneficial and necessary to quit smoking early, even if you smoke a small amount of cigarettes.

Respiratory Mechanics and Gas Exchange in Acute Respiratory Distress Syndrome Associated with COVID-19

Aim. To compare respiratory mechanics and gas exchange in patients with acute respiratory distress syndrome (ARDS) with and without COVID-19.Material and methods. We examined 96 patients, who were divided into two groups. The main group included 48 patients with COVID-19-associated ARDS. The control group included 48 patients with ARDS not associated with COVID-19. Most characteristic patients were selected for the following baseline parameters: age, sex, SAPS II score, disease severity, plateau pressure (Pplateau), oxygenation index (PaO₂/FiO₂), and arterial-alveolar oxygen gradient (A-aO₂). Respiratory mechanics and gas exchange parameters assessed immediately after ARDS diagnosis and on days 1, 3 and 7 of treatment included arterial oxygen (PaO₂) and carbon dioxide (PaCO₂) pressure, tidal volume (Vt), respiratory rate (RR), respiratory minute volume (RMV), positive end expiratory pressure (PEEP), and Pplateau.Results. Patients in the main group had higher Vt (9.7 vs. 5.1 ml/kg, P&lt;0.001), RR (38 vs. 30 min-1, P&lt;0.001), and RMV (27.7 vs. 10.5 l/min, P&lt;0.001). Control group patients showed hypercapnia (PaCO₂ 43 vs. 38 mmHg, P&lt;0.001), lower respiratory compliance (30 vs. 48 ml/cm H₂O, P&lt;0.001) and ventilation ratio (VR) (1.5 vs. 2.0, P&lt;0.01). Lower PEEP values were required for patients in the main group. However, despite the higher rate of tracheal intubation in the control group (50% vs 16.7%) in the initial period of intensive care, the proportion of patients receiving invasive lung ventilation was significantly higher in the main group (33.3% vs.14.6%) by day 7.Conclusion. The initial phase (the first 7 days) of ARDS associated with COVID-19 is characterized by higher values of Vt, RR and RMV, as well as lung compliance vs «typical» ARDS with almost identical PaO₂/FiO₂ values.

Non-invasive ventilation for preoxygenation before general anesthesia: a systematic review and meta-analysis of randomized controlled trials

Background and objectivesPreoxygenation is crucial for providing sufficient oxygen reservoir to a patient before intubation and enables the extension of the period between breathing termination and critical desaturation (safe apnoea time). Conventionally, face mask ventilation is used for preoxygenation. Non-invasive ventilation is a new preoxygenation method. The study objective was to compare the outcomes of non-invasive ventilation and face mask ventilation for preoxygenation.MethodPubMed, Embase, Cochrane Library, and the ClinicalTrials.gov registry were searched for eligible studies published from database inception to September 2021. Individual effect sizes were standardized, and a meta-analysis was conducted using random effects models to calculate the pooled effect size. Inclusion criteria were randomised controlled trials of comparing the outcomes of non-invasive ventilation or face mask ventilation for preoxygenation in patients scheduled for surgeries. The primary outcome was safe apnea time, and the secondary outcomes were post-operative complications, number of patients who achieved the expired O2 fraction (FeO2) after 3 min of preoxygenation, minimal SpO2 during tracheal intubation, partial pressure of oxygen in the arterial blood (PaO2) and partial pressure of carbon dioxide (PaCO2) after preoxygenation, and PaO2 and PaCO2 after tracheal intubation.Results13 trials were eligible for inclusion in this study. Significant differences were observed in safe apnoea time, number of patients who achieved FeO2 90% after preoxygenation for 3 min, and PaO2 and PaCO2 after preoxygenation and tracheal intubation. Only in the non-obese subgroup, no significant difference was observed in safe apnoea time (mean difference: 125.38, 95% confidence interval: − 12.26 to 263.03).ConclusionNon-invasive ventilation appeared to be more effective than conventional methods for preoxygenation. We recommend non-invasive ventilation based on our results.

Ventilatory neural drive in chronically hypercapnic patients with COPD: effects of sleep and nocturnal noninvasive ventilation.

Sleep brings major challenges for the control of ventilation in humans, particularly the regulation of arterial carbon dioxide pressure (P aCO2 ). In patients with COPD, chronic hypercapnia is associated with increased mortality. Therefore, nocturnal high-level noninvasive positive-pressure ventilation (NIV) is recommended with the intention to reduce P aCO2 down to normocapnia. However, the long-term physiological consequences of P aCO2 "correction" on the mechanics of breathing, gas exchange efficiency and resulting symptoms (i.e. dyspnoea) remain poorly understood. Investigating the influence of sleep on the neural drive to breathe and its translation to the mechanical act of breathing is of foremost relevance to create a solid rationale for the use of nocturnal NIV. In this review, we critically discuss the mechanisms by which sleep influences ventilatory neural drive and mechanical consequences in healthy subjects and hypercapnic patients with advanced COPD. We then discuss the available literature on the effects of nocturnal NIV on ventilatory neural drive and respiratory mechanics, highlighting open avenues for further investigation.

Increased Respiratory Drive after Prolonged Isoflurane Sedation: A Retrospective Cohort Study.

Low-dose isoflurane stimulates spontaneous breathing. We, therefore, tested the hypothesis that isoflurane compared to propofol sedation for at least 48 h is associated with increased respiratory drive in intensive care patients after sedation stop. All patients in our intensive care unit receiving at least 48 h of isoflurane or propofol sedation in 2019 were included. The primary outcome was increased respiratory drive over 72 h after sedation stop, defined as an arterial carbon dioxide pressure below 35 mmHg and a base excess more than −2 mmol/L. Secondary outcomes were acid–base balance and ventilatory parameters. We analyzed 64 patients, 23 patients sedated with isoflurane and 41 patients sedated with propofol. Patients sedated with isoflurane were about three times as likely to show increased respiratory drive after sedation stop than those sedated with propofol: adjusted risk ratio [95% confidence interval]: 2.9 [1.3, 6.5], p = 0.010. After sedation stop, tidal volumes were significantly greater and arterial carbon dioxide partial pressures were significantly lower, while respiratory rates did not differ in isoflurane versus propofol-sedated patients. In conclusion, prolonged isoflurane use in intensive care patients is associated with increased respiratory drive after sedation stop. Beneficial effects of isoflurane sedation on respiratory drive may, thus, extend beyond the actual period of sedation.

Determinants of Arterial Pressure of Oxygen and Carbon Dioxide in Patients Supported by Veno-Arterial ECMO.

Background: The present study aimed to assess the determinants of arterial partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2) in the early phase of veno-arterial extracorporeal membrane oxygenation (VA ECMO) support. Even though the guidelines considered both the risks of hypoxemia and hyperoxemia during ECMO support, there are a lack of data concerning the patients supported by VA ECMO. Methods: This is a retrospective, monocentric, observational cohort study in a university-affiliated cardiac intensive care unit. Hemodynamic parameters, ECMO parameters, ventilator settings, and blood gas analyses were collected at several time points during the first 48 h of VA ECMO support. For each timepoint, the blood samples were drawn simultaneously from the right radial artery catheter, VA ECMO venous line (before the oxygenator), and from VA ECMO arterial line (after the oxygenator). Univariate followed by multivariate mixed-model analyses were performed for longitudinal data analyses. Results: Forty-five patients with femoro-femoral peripheral VA ECMO were included. In multivariate analysis, the patients’ PaO2 was independently associated with QEC, FDO2, and time of measurement. The patients’ PaCO2 was associated with the sweep rate flow and the PpreCO2. Conclusions: During acute VA ECMO support, the main determinants of patient oxygenation are determined by VA ECMO parameters.

Prognostic predictive value of intracranial pressure and cerebral oxygen metabolism monitoring in patients with spontaneous intracerebral hemorrhage

ObjectiveOur study aimed to investigate the predictive value of intracranial pressure (ICP) and cerebral oxygen metabolism monitoring in the postoperative prognosis of patients with spontaneous intracerebral hemorrhage (SICH).MethodsThe clinical data of 55 patients with SICH treated by neurosurgery were analyzed retrospectively. These patients were divided into two groups based on postoperative Glasgow Outcome Scale (GOS) scores, i.e., the poor prognosis group (GOS I-III) and the good prognosis group (GOS IV and V). Next, the ICP and cerebral oxygen metabolism indexes, such as brain temperature (BT), cerebral perfusion pressure (CPP), internal jugular venous oxygen saturation (SjvO2), and arterial partial pressure of carbon dioxide (PaCO2), were recorded after the operation. Further, the prognostic differences between the two groups were compared, and the predictive values were evaluated using the receiver operating characteristic curve (ROC) and area under the curve (AUC).ResultsThe results showed that the average ICP and BT in the good prognosis group were lower than those in the poor prognosis group. However, the CPP and SjvO2 in the good prognosis group were higher than those in the poor prognosis group. Moreover, the incidence of low PaCO2 in the poor prognosis group was higher than that in the good prognosis group.ConclusionsOur results demonstrated that the average ICP, BT, CPP, SjvO2, and arterial PaCO2 may reflect the changes in brain function and cerebral blood flow, which are significantly correlated with the prognosis of patients. Further, our findings indicated that the combined postoperative ICP levels with cerebral oxygen metabolism indexes could guide clinical treatments and predict prognosis.

High-flow nasal cannula oxygen therapy during anesthesia recovery for older orthopedic surgery patients: A prospective randomized controlled trial.

BACKGROUNDHypoxemia is a common complication in older patients during postoperative recovery and can cause pulmonary complications. Therefore, reducing the incidence of postoperative hypoxemia is a clinical concern.AIMTo investigate the clinical efficacy of high-flow nasal cannula oxygen (HFNCO) in the resuscitation period of older orthopedic patients.METHODSIn this prospective randomized controlled trial, 60 older patients who underwent orthopedic surgery under general anesthesia were randomly divided into two groups: those who used conventional face mask and those who used HFNCO. All patients were treated with 60% oxygen for 1 h after extubation. Patients in the conventional face mask group were treated with a combination of air (2 L) and oxygen (2 L) using a traditional mask, whereas those in the HFNCO group were treated with HFNCO at a constant temperature of 34 °C and flow rate of 40 L/min. We assessed the effectiveness of oxygen therapy by monitoring the patients’ arterial blood gas, peripheral oxygen saturation, and postoperative complications.RESULTSThe characteristics of the patients were comparable between the groups. One hour after extubation, patients in HFNCO group had a significantly higher arterial partial pressure of oxygen (paO2) than that of patients in conventional face mask group (P < 0.001). At extubation and 1 h after extubation, patients in both groups showed a significantly higher arterial partial pressure of carbon dioxide (paCO2) than the baseline levels (P < 0.001). There were no differences in the saturation of peripheral oxygen, paO2, and paCO2 between the groups before anesthesia and before extubation (P > 0.05). There were statistically significant differences in paO2 between the two groups before anesthesia and 1 h after extubation and immediately after extubation and 1 h after extubation (P < 0.001). However, there were no significant differences in the oxygen tolerance score before leaving the room, airway humidification, and pulmonary complications 3 d after surgery between the two groups (P > 0.05).CONCLUSIONHFNCO can improve oxygen partial pressure and respiratory function in elderly patients undergoing orthopedic surgery under general endotracheal anesthesia. Thus, HFNCO can be used to prevent postoperative hypoxemia.

The effect of high-frequency oscillatory ventilator combined with pulmonary surfactant in the treatment of neonatal respiratory distress syndrome.

Objective:To investigate the efficacy of high-frequency oscillatory ventilation (HFOV) combined with pulmonary surfactant (PS) in the treatment of neonatal respiratory distress syndrome (NRDS).Methods:This study is a retrospective clinical study. Seventy-two NRDS neonates were selected as the subjects from November 2019 to November 2020, and divided into observation group (40 cases, HFOV treatment) and control group (32 cases, conventional mechanical ventilation treatment). All cases were treated with PS and comprehensive treatment. The therapeutic effect, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), Percentage of inhaled oxygen concentration (FiO2), mean arterialpressure, oxygenation index (OI), and complications were compared in the 2 groups.Results:The total effective rate of the observation group was 90.0%, significantly higher than that of the control group. After treatment, the observation group has higher PaO2 levels and lower levels of PaCO2, mean arterial pressure, FiO2, and OI than the control group. There was no significant difference in the incidence of complications between the 2 groups.Conclusion:HFOV combined with PS has a significant effect on NRDS, which can improve the arterial blood gas index without increasing the incidence of complications.

Effect of Noninvasive Positive Pressure Ventilation on Prognosis and Blood Gas Level in COPD Patients Complicated with Respiratory Failure.

Chronic obstructive pulmonary disease (COPD) is a respiratory disease caused by chronic bronchitis, which seriously threatens the life safety of patients. Noninvasive positive pressure ventilation (NIPPV) has great advantages in its treatment. Here, we explore the effect of NIPPV on prognosis and blood gas level in COPD patients complicated with respiratory failure (RF). A case control study was retrospectively analyzed, where 36 COPD patients with RF were regarded as the regular group to carry on the routine treatment, and 42 patients were assigned to the research group to carry out the routine treatment plus NIPPV. The monofactorial analysis showed that the overall response rate, forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC in the research group were higher than those in the regular group, while partial pressure of arterial carbondioxide (PaCO2), posttreatment endotracheal intubation (EI), length of stay (LOS), tumor necrosis factor (TNF-α), interleukin (IL)-6, IL-1β, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and modified Medical Research Council (mMRC) scores in the research group were lower than those in the regular group. These results indicated that NIPPV can improve the curative effect of emergency medicine patients with RF, improve BG level and PF, reduce inflammation, and facilitate patient's recovery.

Retroperitoneoscopic Surgery in Children Does Not Cause Pathological Desaturation in Cerebral/Renal Oxygenation on Near-Infrared Spectroscopy Compared with Laparoscopic and Thoracoscopic Surgery.

Introduction: Cerebral and renal regional oxygen saturation (C-rSO2 and R-rSO2, respectively) were monitored using near-infrared spectroscopy in pediatric patients (range: 0.3-14.3 years) during minimally invasive surgery (MIS) taking at least 3 hours performed by laparoscopy (Lap), thoracoscopy (Tho), or retroperitoneoscopy (Ret) from January 2019 to December 2021. Materials and Methods: Criteria compared were operative time, preoperative/intraoperative hemoglobin, blood loss, mean arterial pressure, arterial partial pressure of carbon dioxide (PaCO2), peripheral oxygen saturation (SpO2), C-rSO2, and R-rSO2. Pathological desaturation (PD) was defined as >20% decrease from baseline, and statistical significance as P < .05. Results: Subjects (n = 79) were similar for gender, age, and body mass index. MIS procedures were: Lap = 45, Tho = 20, Ret = 14; one Lap case required conversion for severe adhesions, not PD. Intraoperative PaCO2 (mmHg) was significantly higher in Tho (maximum: 59.5 ± 17.0, minimum: 39.9 ± 7.5) versus Lap (maximum: 39.9 ± 5.1, minimum: 34.6 ± 3.9) and Ret (maximum: 37.8 ± 4.2, minimum: 35.0 ± 3.3); P < .0001 (maximum), P = .0013 (minimum). Minimum intraoperative SpO2 was significantly lower in Tho (P < .0001). Mean operative times were significantly shorter in Tho (259 ± 114 minutes) versus Lap (433 ± 154 minutes) and Ret (342 ± 100 minutes); P < .0001, respectively. PD was absent during Ret (C-rSO2: 0/14 = 0% and R-rSO2: 0/14 = 0%). Differences in PD for Lap (C-rSO2: 7/45 = 15.6% and R-rSO2: 10/45 = 22.2%) and Tho (C-rSO2: 9/20 = 45.0%, and R-rSO2: 7/20 = 35.0%) were significant; P = .0028 for C-rSO2 and P = .0497 for R-rSO2. Hemoglobin and blood loss were similar. Conclusions: PD was absent during Ret, despite longer operative times. If Ret is indicated for a procedure, neurodevelopmental sequelae of MIS could be minimized.

Clustering identifies endotypes of traumatic brain injury in an intensive care cohort: a CENTER-TBI study

BackgroundWhile the Glasgow coma scale (GCS) is one of the strongest outcome predictors, the current classification of traumatic brain injury (TBI) as ‘mild’, ‘moderate’ or ‘severe’ based on this fails to capture enormous heterogeneity in pathophysiology and treatment response. We hypothesized that data-driven characterization of TBI could identify distinct endotypes and give mechanistic insights.MethodsWe developed an unsupervised statistical clustering model based on a mixture of probabilistic graphs for presentation (< 24 h) demographic, clinical, physiological, laboratory and imaging data to identify subgroups of TBI patients admitted to the intensive care unit in the CENTER-TBI dataset (N = 1,728). A cluster similarity index was used for robust determination of optimal cluster number. Mutual information was used to quantify feature importance and for cluster interpretation.ResultsSix stable endotypes were identified with distinct GCS and composite systemic metabolic stress profiles, distinguished by GCS, blood lactate, oxygen saturation, serum creatinine, glucose, base excess, pH, arterial partial pressure of carbon dioxide, and body temperature. Notably, a cluster with ‘moderate’ TBI (by traditional classification) and deranged metabolic profile, had a worse outcome than a cluster with ‘severe’ GCS and a normal metabolic profile. Addition of cluster labels significantly improved the prognostic precision of the IMPACT (International Mission for Prognosis and Analysis of Clinical trials in TBI) extended model, for prediction of both unfavourable outcome and mortality (both p < 0.001).ConclusionsSix stable and clinically distinct TBI endotypes were identified by probabilistic unsupervised clustering. In addition to presenting neurology, a profile of biochemical derangement was found to be an important distinguishing feature that was both biologically plausible and associated with outcome. Our work motivates refining current TBI classifications with factors describing metabolic stress. Such data-driven clusters suggest TBI endotypes that merit investigation to identify bespoke treatment strategies to improve care.Trial registrationThe core study was registered with ClinicalTrials.gov, number NCT02210221, registered on August 06, 2014, with Resource Identification Portal (RRID: SCR_015582).