Introduction: Laparoscopic Cholecystectomy uses carbon dioxide (CO2) which affects the respiratory, cardiovascular and renal system. The residual CO2 induces phrenic nerve irritation, manifesting as shoulder and abdominal pain. Recruitment maneuvers opens the lungs and helps expelling this residual carbon dioxide. However, there are limited studies on its role to hemodynamics especially in patients undergoing abdominal laparoscopic procedures. Methods: Sixty patients (51 15.1) scheduled for laparoscopic cholecystectomy under General Endotracheal Anesthesia were randomly allocated to two groups. The control group (Group C) underwent standard laparoscopic cholecystectomy procedures. The experimental group (Group R) was placed in a Trendelenburg and was given 4-5 manual pulmonary inflations at a pressure of 40cmH20. The blood pressure, heart rate, respiratory rate and oxygen saturation, as well as the post operative site pain and shoulder pain were measured using the Numerical Pain Scale (NPS) were monitored at 0, 1 and 2 hours post operatively. Results: The demographics and preoperative vital signs were comparable. The mean systolic blood pressure [119.5 vs 131.5; p=0.002], mean arterial pressure [91.8 vs 95.3; p=0.049], heart rate [74.9 vs 87.5; p <0.001] and respiratory rate [15.7 vs 16.2; p=0.02] were all differrent only during the immediate post operative period. The mean shoulder pain was lower in Group R immediately [1.9 ± 1.2; p=0.01] and 1 hour after surgery [0.7 ± 0.8; p=0.01]. Conclusion Recruitment maneuver significantly reduces the shoulder pain scores after laparoscopic cholecystectomy. It causes a decrease in blood pressure, heart rate and mean arterial pressure in the immediate post operative period.
Cholecystectomy, Laparoscopic ; Shoulder Pain ; Hemodynamics ; Carbon Dioxide

INTRODUCTION: Laryngeal mask airway (LMA), which is used in difficult airway maintenance conditions during emergencies, is rarely used in prolonged surgery despite its advantages over endotracheal tube (ETT). In this study, we conducted a comparative analysis of intraoperative gas exchanges between second-generation LMA and ETT during prolonged laparoscopic abdominal surgery. METHODS: Prolonged surgery was defined as a surgery lasting more than 2 h. In total, 394 patients who underwent laparoscopic liver resection via either second-generation LMA or ETT were retrospectively analysed. The following parameters were compared between the two groups of patients: end-tidal pressure of carbon dioxide (ETCO₂), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (PIP), arterial partial pressure of carbon dioxide (PaCO₂), pH and ratio of arterial partial pressure of oxygen to fractional inspired oxygen (PFR) during surgery. In addition, the incidence of postoperative pulmonary complications (PPCs), including pulmonary aspiration, was compared. RESULTS: The values of ETCO₂, TV, RR and PIP during pneumoperitoneum were comparable between the two groups. Although PaCO₂ at 2 h after induction was higher in patients in the LMA group (40.5 vs. 38.5 mmHg, P < 0.001), the pH and PFR values of the two groups were comparable. The incidence of PPC was similar. CONCLUSION During prolonged laparoscopic abdominal surgery, second-generation LMA facilitates adequate intraoperative gas exchange and may serve as an alternative to ETT.
Humans ; Laryngeal Masks ; Carbon Dioxide ; Retrospective Studies ; Intubation, Intratracheal ; Laparoscopy/adverse effects* ; Postoperative Complications/etiology* ; Oxygen

The purpose of this study was to investigate the effect of glutamate and its ionotropic receptor agonists on the response to acute hypoxia in rat carotid body in vitro. Briefly, after SD rats were anesthetized and decapitated, the bilateral carotid bifurcations were rapidly isolated. Then bifurcation was placed into a recording chamber perfused with 95% O₂-5% CO₂ saturated Kreb's solution. The carotid body-sinus nerve complex was dissected, and the carotid sinus nerve discharge was recorded using a suction electrode. To detect the response of carotid body to acute hypoxia, the chamber was perfused with 5% O₂-5% CO₂-90% N₂ saturated Kreb's solution for a period of 100 s at an interval of 15 min. To observe the effect of glutamate, ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor agonist AMPA or N-methyl-D-aspartate (NMDA) receptor agonist NMDA on the response to acute hypoxia in rat carotid body, the chamber was perfused with 5% O₂-5% CO₂-90% N₂ saturated Kreb's solution containing the corresponding reagent. The results showed that glutamate (20 μmol/L), AMPA (5 μmol/L) or NMDA (10 μmol/L) inhibited the acute hypoxia-induced enhancement of carotid sinus nerve activity, and these inhibitory effects were dose-dependent. In summary, the activation of glutamate ionotropic receptors appears to exert an inhibitory effect on the response to acute hypoxia in carotid body of rats.
Rats ; Animals ; Glutamic Acid/pharmacology* ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology* ; N-Methylaspartate/pharmacology* ; Carotid Body ; Rats, Sprague-Dawley ; Carbon Dioxide ; Receptors, N-Methyl-D-Aspartate ; Receptors, AMPA ; Hypoxia

C1 gases including CO, CO₂ and CH₄, are mainly derived from terrestrial biological activities, industrial waste gas and gasification syngas. Particularly, CO₂ and CH₄ are two of the most important greenhouse gases contributing to climate change. Bioconversion of C1 gases is not only a promising solution to addressing the problem of waste gases emission, but also a novel route to produce fuels or chemicals. In the past few years, C1-gas-utilizing microorganisms have drawn much attention and a variety of gene-editing technologies have been applied to improve their product yields or to expand product portfolios. This article reviewed the biological characteristics, aerobic or anaerobic metabolic pathways as well as the metabolic products of methanotrophs, autotrophic acetogens, and carboxydotrophic bacteria. In addition, gene-editing technologies (e.g. gene interruption technology using homologous recombination, group Ⅱ intron ClosTron technology, CRISPR/Cas gene editing and phage recombinase-mediated efficient integration of large DNA fragments) and their application in these C1-gas-utilizing microorganisms were also summarized.
Gene Editing ; Gases ; Carbon Dioxide ; Genetic Engineering ; Cloning, Molecular

Enzyme-catalyzed CO₂ reduction to value-added commodities is important for alleviating the global environmental issues and energy crises due to high selectivity and mild conditions. Owing to high energy density, formic acid or methanol produced from CO₂ using formate dehydrogenase (FDH) or multi-enzyme cascades are promising target chemicals for CO₂ utilization. However, the low activity, poor stability and low reusability of key enzymes involved in such process hampered its large-scale application. Enzyme immobilization provides an effective solution to these problems and significant progress have been made in immobilization carriers. Moreover, integration of enzyme immobilization with other catalysis techniques have been explored extensively. This review summarized the recent advances in the immobilization of enzymes using membranes, inorganic materials, metal-organic frameworks, covalent organic frameworks and other carriers, and illustrated the characteristics and advantages of different immobilization materials and immobilization methods. The synergistic effects and applications of immobilized enzymes and electrocatalytic or photocatalytic coupling reaction systems for CO₂ reduction were further summarized. Finally, the current challenges of enzyme immobilization technology and coupling reaction systems were pointed out and their development prospects were presented.
Enzymes, Immobilized ; Carbon Dioxide ; Catalysis ; Formate Dehydrogenases ; Metal-Organic Frameworks

OBJECTIVES: To investigate the therapeutic efficacy of volume-guaranteed high frequency oscillation ventilation (HFOV-VG) versus conventional mechanical ventilation (CMV) in the treatment of preterm infants with respiratory failure. METHODS: A prospective study was conducted on 112 preterm infants with respiratory failure (a gestational age of 28-34 weeks) who were admitted to the Department of Neonatology, Jiangyin Hospital Affiliated to Medical School of Southeast University, from October 2018 to December 2022. The infants were randomly divided into an HFOV-VG group (44 infants) and a CMV group (68 infants) using the coin tossing method based on the mode of mechanical ventilation. The therapeutic efficacy was compared between the two groups. RESULTS: After 24 hours of treatment, both the HFOV-VG and CMV groups showed significant improvements in arterial blood pH, partial pressure of oxygen, partial pressure of carbon dioxide, and partial pressure of oxygen/fractional concentration of inspired oxygen ratio (P<0.05), and the HFOV-VG group had better improvements than the CMV group (P<0.05). There were no significant differences between the two groups in the incidence rate of complications, 28-day mortality rate, and length of hospital stay (P>0.05), but the HFOV-VG group had a significantly shorter duration of invasive mechanical ventilation than the CMV group (P<0.05). The follow-up at the corrected age of 6 months showed that there were no significant differences between the two groups in the scores of developmental quotient, gross motor function, fine motor function, adaptive ability, language, and social behavior in the Pediatric Neuropsychological Development Scale (P>0.05). CONCLUSIONS Compared with CMV mode, HFOV-VG mode improves partial pressure of oxygen and promotes carbon dioxide elimination, thereby enhancing oxygenation and shortening the duration of mechanical ventilation in preterm infants with respiratory failure, while it has no significant impact on short-term neurobehavioral development in these infants.
Infant ; Child ; Infant, Newborn ; Humans ; Infant, Premature ; Prospective Studies ; Gestational Age ; Carbon Dioxide ; Respiratory Distress Syndrome, Newborn/therapy* ; High-Frequency Ventilation/methods* ; Respiration, Artificial ; Respiratory Insufficiency/therapy* ; Oxygen ; Cytomegalovirus Infections

OBJECTIVE: To evaluate the effect of transcutaneous acupoint electrical stimulation (TEAS) at Neiguan (PC 6) on general anesthesia under preserving spontaneous breathing in thoracoscopic lobectomy. METHODS: A total of 66 patients of primary lung cancer undergoing thoracoscopic lobectomy were divided to an observation group (33 cases, 1 case discontinued) and a control group (33 cases). In the observation group, TEAS at Neiguan (PC 6) was used 30 min before anesthesia induction till the end of surgery. The surgery time, maximum value of partial pressure of end-tidal carbon dioxide (P_ETCO₂) and minimum value of oxygen saturation (SpO₂) of the two groups were recorded. The dosage of propofol, sufentanil, remifentanil and dexmedetomidine were analyzed. Separately, before induction (T₀), at the start of surgery (T₁), thoracic exploration (T₂) and lobectomy (T₃), as well as 30 min (T₄) and 60 min (T₅) after lobectomy, the mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), serum cortisol (Cor) and norepinephrine (NE) were measured. The time of post anesthesia care unit (PACU) stay, ambulation, flatus, chest drainage and the incidence of nausea and vomiting were compared between the two groups. RESULTS: The maximum value of P_ETCO₂, the dosage of propofol and remifentanil in the observation group were lower than those in the control group (P < 0.05, P < 0.01), the minimum value of SpO₂ in the observation group was higher than that of the control group (P < 0.01). At T₁-T₅, the MAP, HR, serum Cor and NE levels in the observation group were all lower than those in the control group (P < 0.05). The ambulation time, the time for the flatus, chest drainage time, and the incidence of nausea and vomiting in the observation group were all lower than those in the control group (P<0.001, P < 0.01). CONCLUSION For the general anesthesia under preserving spontaneous breathing in thoracoscopic surgery, TEAS at Neiguan (PC 6) relieves stress response, reduces opioids dosage and promotes postoperative recovery.
Humans ; Acupuncture Points ; Carbon Dioxide ; Flatulence ; Propofol ; Remifentanil ; Anesthesia, General ; Nausea ; Norepinephrine ; Electric Stimulation

Extracorporeal carbon dioxide removal is an artificial lung auxiliary technique based on extrapulmonary gas exchange and can effectively remove carbon dioxide and provide oxygenation to a certain extent, and it is one of the effective treatment techniques for hypercapnia developed after mechanical ventilation and extracorporeal membrane oxygenation in recent years and has wide application prospect. This article elaborates on the development, working principle, advantages, classification, complications, and clinical application of extracorporeal carbon dioxide removal, so as to provide a new choice for extracorporeal carbon dioxide removal in clinical practice.
Humans ; Carbon Dioxide ; Extracorporeal Membrane Oxygenation ; Renal Dialysis ; Respiration, Artificial

Objective: To explore the clinical effects of fractional carbon dioxide laser combined with minimally invasive scar release in the treatment of post-acne atrophic scars. Methods: A retrospectively observational study was conducted. From January to June 2021, 60 patients with grade 3 and 4 post-acne atrophic scars who met the inclusion criteria were admitted to the First Affiliated Hospital of Henan University of Traditional Chinese Medicine. According to the adopted treatment methods, 30 patients treated with fractional carbon dioxide laser combined with minimally invasive scar release were included in combined treatment group (19 males and 11 females, aged (26±4) years), and 30 patients treated with fractional carbon dioxide laser alone were included in laser alone group (18 males and 12 females, aged (25±6) years). All the patients received the treatment once every two months, totally 3 times. Before the first treatment and 2 months after the last treatment, the scars were assessed by échelle d'évaluation clinique des cicatrices d'acné (ECCA). In 2 months after the last treatment, the curative effect was evaluated and the total effective rate was calculated according to the ECCA score. The adverse reactions of patients during the treatment were recorded. Data were statistically analyzed with independent sample t test, Wilcoxon rank-sum test, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. Results: Before the first treatment, the ECCA scores of patients in the two groups were similar (P>0.05). In 2 months after the last treatment, the ECCA scores of patients in combined treatment group were significantly lower than those of laser alone group (Z=-2.89, P<0.05). The ECCA scores of patients in combined treatment group and laser alone group in 2 months after the last treatment were both significantly lower than those before the first treatment (with Z values of -4.81 and -4.79, respectively, P<0.05). In 2 months after the last treatment, the treatment in laser alone group cured the scars in 2 patients, and were markedly effective in 13 patients, effective in 7 patients, and ineffective in 8 patients; the treatment in combined treatment group cured the scars in 4 patients, and were markedly effective in 22 patients, effective in 3 patients, and ineffective in one patients. The total effective rate of scar treatment in combined treatment group (96.67%, 29/30) was significantly higher than 73.33% (22/30) in laser alone group (P<0.05). During treatment, in combined treatment group, 3 patients had pain, one patient had redness and swelling, and one patient had pigmentation. In laser alone group, one patient had pain, and 2 patients had pigmentation. No infection occurred in the wounds of all the patients in the two groups. Conclusions: Compared with fractional carbon dioxide laser alone, fractional carbon dioxide laser combined with minimally invasive scar release for post-acne atrophic scars can result in a higher total effective rate, with simple operation and good effect, so it is worthy of clinical application.
Male ; Female ; Humans ; Cicatrix/therapy* ; Retrospective Studies ; Treatment Outcome ; Lasers, Gas/therapeutic use* ; Acne Vulgaris ; Atrophy ; Pain ; Carbon Dioxide

The use of light energy to drive carbon dioxide (CO₂) reduction for production of chemicals is of great significance for relieving environmental pressure and solving energy crisis. Photocapture, photoelectricity conversion and CO₂ fixation are the key factors affecting the efficiency of photosynthesis, and thus also affect the efficiency of CO₂ utilization. To solve the above problems, this review systematically summarizes the construction, optimization and application of light-driven hybrid system from the perspective of combining biochemistry and metabolic engineering. We introduce the latest research progress of light-driven CO₂ reduction for biosynthesis of chemicals from three aspects: enzyme hybrid system, biological hybrid system and application of these hybrid system. In the aspect of enzyme hybrid system, many strategies were adopted such as improving enzyme catalytic activity and enhancing enzyme stability. In the aspect of biological hybrid system, many methods were used including enhancing biological light harvesting capacity, optimizing reducing power supply and improving energy regeneration. In terms of the applications, hybrid systems have been used in the production of one-carbon compounds, biofuels and biofoods. Finally, the future development direction of artificial photosynthetic system is prospected from the aspects of nanomaterials (including organic and inorganic materials) and biocatalysts (including enzymes and microorganisms).
Carbon Dioxide/metabolism* ; Photosynthesis ; Metabolic Engineering