The efficacy of lumbar erector spinae plane block for postoperative analgesia management in patients undergoing lumbar unilateral bi-portal endoscopic surgery: a prospective randomized controlled trial.

BACKGROUND: The efficacy and reliability of erector spinae plane block (ESPB) in posterior open lumbar spine surgery has been demonstrated; however, few randomized controlled trials of lumbar ESPB (L-ESPB) in lumbar unilateral bi-portal endoscopic (UBE) surgery have been reported. METHODS: A total of 120 patients, aged 18 to 65 (who underwent elective lumbar UBE surgery under general anesthesia and exhibited an American Society of Anesthesiologists physical status of I to III) were randomly assigned in a 1:1 ratio to the ESPB group and the Control group. Ultrasound(US)-guided unilateral single-shot 0.25% ropivacaine L-ESPB was performed in the ESPB group, but not in the control group. Postoperative analgesic strategy for all patients: patient controlled intravenous analgesia (PCIA, diluted and dosed with fentanyl alone) was initiated immediately after surgery combined with oral compound codeine phosphate and ibuprofen sustained release tablets (1 tablet containing ibuprofen 200 mg and codeine 13 mg, 1 tablet/q12h) commenced 6 h postoperatively. We collected and compared patient-centred correlates intraoperatively and 48 h postoperatively. The primary outcomes were intraoperative and postoperative opioid consumption and postoperative quality of recovery-15 (QoR-15) scores. RESULTS: Compared to the control group (n = 56), the ESPB group (n = 58) significantly reduced intraoperative remifentanil consumption (estimated median difference - 280 mcg, 95% confidence interval [CI] - 360 to - 200, p < 0.001, power = 100%); significantly reduced fentanyl consumption at 24 h postoperatively (estimated median difference - 80mcg, 95%[CI] - 128 to - 32, p = 0.001, power = 90%); and significantly enhanced the QoR-15 score at 24 h postoperatively (estimated median difference 11, 95%[CI] 8 to 14, p < 0.001, power = 100%). Compared to the control group, the ESPB group enhanced the resting numeric rating scale (NRS) score up to 8 h postoperatively, and the active movement NRS score up to 4 h postoperatively. The incidence of postoperative nausea and vomiting (PONV) (p = 0.015, power = 70%), abdominal distension (p = 0.024, power = 64%), and muscular calf vein thrombosis (MCVT) (p = 0.033, power = 58%) was lower in the ESPB group than in the control group. Moreover, the occurrence of L-ESPB related adverse reactions was not found herein. CONCLUSION: US-guided L-ESPB reduces intraoperative and 24 h postoperative opioid consumption and improves patients' QoR-15 scores at 24 h postoperatively. L-ESPB can be safely and effectively utilized in lumbar UBE surgery. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200061908 , date of registration: 10/07/2022. Registry URL.

Comparison of the effect of dexmedetomidine intrathecal injection and intravenous infusion on subarachnoid blockade during knee arthroscopy procedures: a randomized controlled trial.

BACKGROUND: Comparison of whether intrathecal dexmedetomidine prolongs spinal anesthesia-associated sensorimotor blockade more than intravenous infusion during knee arthroscopy procedures performed under subarachnoid blockade. METHODS: Ninety patients aged 18-75 years, ASA class I-II, who underwent knee arthroscopy between October 2022 and April 2023 were randomized into intrathecal、intravenous and control groups.Subjects received three modes of administration: an intrathecal group (2 ml of 1% ropivacaine + 1 ml of 5 µg dexmedetomidine, along with intravenous saline infusion), an intravenous group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, with dexmedetomidine pumped intravenously at a dose of 0.5 µg/kg/h), and a control group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, along with intravenous saline infusion). Total analgesic duration, duration of sensory and motor blockade, Ramsay sedation score, Visual Analogue Score (VAS) at different postoperative time points, and occurrence of adverse effects were recorded. RESULTS: The total analgesia duration was significantly longer in the intrathecal group than in the intravenous and control groups (352.13 ± 51.70 min VS 273.47 ± 62.57 min VS 241.41 ± 59.22 min, P < 0.001).The onset of sensory block was shorter in the intrathecal group than in the intravenous and control groups (4 [3-4]min VS 5 [4-5]min VS 5 [4-5]min; P < 0.001);the onset of motor block was shorter in the intrathecal group than in the intravenous group and the control group (5 [4-5]min VS 5 [5-6]min VS 6[5.5-7]min; P < 0.001).Sedation scores were higher in the intravenous group than in the intrathecal and control groups (P < 0.001). At 5 h postoperatively, the VAS score in the intrathecal group was lower than that in the intravenous and control groups (P < 0.001). At 24 h postoperatively, the VAS score in the intrathecal group was lower than that in the control group (P < 0.001). In addition, the incidence of bradycardia was significantly higher in the intravenous group than in the intrathecal and control groups (30%, 6.5%, and 3.4%, respectively; P = 0.018, P = 0.007). CONCLUSIONS: Intrathecal administration of dexmedetomidine did prolong the total analgesia duration, as well as accelerate the onset of sensory-motor blockade compared with intravenous infusion, and did not result in any hemodynamic instability or other adverse events at the doses studied. TRIAL REGISTRATION: This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 26/09/2023 with the registration number ChiCTR2300076170.

Median effective dose (ED50) of esketamine combined with propofol for children to inhibit response of gastroscope insertion.

BACKGROUND: Propofol is the most commonly used drug for procedural sedation during gastroscopy. However, independent use of propofol can lead to increased dosage and additional side effects. Esketamine was found to be exceptional in combination with propofol for painless gastroscopy. No studies have calculated the median effective dose (ED50) of esketamine combined with propofol in pediatric painless gastroscopy. Here, we designed a research to study the ED50 of esketamine combined with propofol using the Dixon and Massey up-and-down sequential method for inhibiting the response of gastroscope insertion. METHODS: Children who met the inclusion and exclusion criteria were included in this study. Propofol and esketamine were used as anesthetics for painless gastroscopy in children. To explore the ED50, the initial propofol dose was set at 3 mg/kg in all children. The first child was given an esketamine dose of 0.1 mg/kg, followed by 30 s of slow bolus injection propofol. If anesthesia induction failed (coughing or body movement of children during gastroscope insertion), the esketamine dose was elevated in the next child, with a interval difference of 0.05 mg/kg. Otherwise, if the anesthesia induction was successful, the next dosage was reduced by 0.05 mg/kg. The study was stopped if nine crossover inflection points were reached. The ED50 of esketamine was calculated using probit regression, and the blood pressure, pulse oxygen saturation, heart rate, recovery time, and side effects were recorded in all children. RESULTS: A total of 26 children were included in this study. The ED50 of esketamine combined with 3 mg/kg propofol was 0.143 mg/kg (95% CI 0.047-0.398 mg/kg). The total consumption of propofol was 16.04 ± 5.37 mg. The recovery time was 16.38 ± 8.70 min. Adverse effects recorded were delayed awakening in two cases and increased oral secretions of another child during the examination inducing cough and hypoxemia (86% was the lowest). DISCUSSION: The ED50 of esketamine was 0.143 mg/kg when combined with 3 mg/kg propofol for successful sedation in pediatric gastroscope insertion. This sub-anaesthetic dose of esketamine was safe and efficacious with few complications in pediatric painless gastroscopy. TRIAL REGISTRATION: The study was registered at the Chinese Clinical Trial Registry ( www.chictr.org.cn ; registration number: ChiCTR2100052830 on 06/11/2021).

[Research progress of signal pathways of microglia activation in sleep disorders].

Sleep is an extremely important physiological state to maintain human life. Sleep disorders can not only cause anxiety and depression, but also induce multi-system diseases that seriously affect brain function and physical health. The neuroinflammation is a key pathological process after sleep disorders, which can induce a series of nervous system diseases. In recent years, the role of microglia activation in neuroinflammation has been paid more and more attention and become a research hotspot in this field. The imbalance of the central microenvironment after sleep disorders leads to changes in the activation and polarization of microglia, which triggers neuroinflammatory response. The activation and polarization of microglia in the sleep disorders are regulated by multiple signaling pathways and complex molecular mechanisms. This paper summarizes five signaling pathways of microglia activation in central inflammation induced by sleep disorders, including P2X7 receptor (P2X7R), p38MAPK, Toll-like receptor 4 (TLR4)/NF-κB, JAK/STAT, and α7 nicotinic acetylcholine receptor (α7-nAChR) pathways, in order to provide reference for further research and clinical treatment targets selection of sleep disorders.

CBLB502, a Toll-like receptor 5 agonist, offers protection against radiation-induced male reproductive system damage in mice.

CBLB502, a Toll-like receptor (TLR)5 agonist derived from Salmonella flagellin, was shown to protect mammalian hematopoietic and gastrointestinal systems from acute irradiation syndrome and to stimulate regeneration. To explore whether CBLB502 can improve testicular injuries caused by irradiation, mice were intraperitoneally injected with 0.2 mg/kg CBLB502 or vehicle control 30 min prior to applying 5.0 Gy ionizing radiation (IR). We observed these mice for the following 120 days and determined that CBLB502 pretreatment alleviated IR-induced oxidative stress, alleviated the distorted architecture of seminiferous tubules, reversed the decline of sperm quantity and quality, and helped recover male mouse fertility. Additionally, CBLB502 efficiently reduced DNA damage and chromosomal aberrations in IR-treated mice and their offspring. Due to the suppression of p53-dependent apoptosis, in IR-treated mice, CBLB502 was shown to significantly activate the nuclear factor kappa B (NFκB) pathway and reduce the apoptotic rate in association with an increase in anti-apoptotic B-cell lymphoma 2 levels and a decrease in the levels of DNA repair protein and proliferating cell nuclear antigen. Moreover, an IR-induced reduction in serum testosterone and superoxide dismutase levels and an increase in malondialdehyde levels were considerably reversed in CBLB502-pretreated mice. No significant reverse effects were found in Tlr5 knockout mice, suggesting that protection of the testis against IR by CBLB502 is primarily dependent on the TLR5 signaling pathway. Our results may help further investigations into potential CBLB502 applications for the protection of the male reproductive system during radiotherapy.

Alda-1 Attenuates Lung Ischemia-Reperfusion Injury by Reducing 4-Hydroxy-2-Nonenal in Alveolar Epithelial Cells.

OBJECTIVES: Excessive oxidative stress is a main cause of lung ischemia-reperfusion injury, which often results in respiratory insufficiency after open-heart surgery for a cardiopulmonary bypass. Previous studies demonstrate that the activation of aldehyde dehydrogenase-2 could significantly reduce the oxidative stress mediated by toxic aldehydes and attenuate cardiac and cerebral ischemia-reperfusion injury. However, both the involvement of aldehydes and the protective effect of the aldehyde dehydrogenase-2 agonist, Alda-1, in lung ischemia-reperfusion injury remain unknown. DESIGN: Prospective laboratory and animal investigation were conducted. SETTING: State Key Laboratory of Cardiovascular Disease. SUBJECTS: Primary human pulmonary alveolar epithelial cells, human pulmonary microvascular endothelial cells, and Sprague-Dawley rats. INTERVENTIONS: A hypoxia/reoxygenation cell-culture model of human pulmonary alveolar epithelial cell, human pulmonary microvascular endothelial cell, and an isolated-perfused lung model were applied to mimic lung ischemia-reperfusion injury. We evaluated the effects of Alda-1 on aldehyde dehydrogenase-2 quantity and activity, on aldehyde levels and pulmonary protection. MEASUREMENTS AND MAIN RESULTS: We have demonstrated that ischemia-reperfusion-induced pulmonary injury concomitantly induced aldehydes accumulation in human pulmonary alveolar epithelial cells and lung tissues, but not in human pulmonary microvascular endothelial cells. Moreover, Alda-1 pretreatment significantly elevated aldehyde dehydrogenase-2 activity, increased surfactant-associated protein C, and attenuated elevation of 4-hydroxy-2-nonenal, apoptosis, intercellular adhesion molecule-1, inflammatory response, and the permeability of pulmonary alveolar capillary barrier, thus alleviated injury. CONCLUSIONS: Our study indicates that the accumulation of 4-hydroxy-2-nonenal plays an important role in lung ischemia-reperfusion injury. Alda-1 pretreatment can attenuate lung ischemia-reperfusion injury, possibly through the activation of aldehyde dehydrogenase-2, which in turn removes 4-hydroxy-2-nonenal in human pulmonary alveolar epithelial cells. Alda-1 pretreatment has clinical implications to protect lungs during cardiopulmonary bypass.

A Novel Combined-Catheter to Monitor Left and Right Atrial Pressures: A Simple and Reliable Method for Pediatric Cardiac Surgery.

OBJECTIVE: To introduce a novel combined-catheter to monitor left and right atrial pressures. DESIGN: Prospective observational study. SETTING: Fuwai Hospital, China. PATIENTS: A total of 113 pediatric patients (77 men), median age 10.3 months, admitted between July 10, 2014, and February 5, 2015, were divided into two groups: the novel-catheter group and the traditional-method group. INTERVENTIONS: All patients received routine anesthesia and surgery. Left atrial pressure and central venous pressure (an estimate of right atrial pressure), measured through a catheter needle during surgery, were identified as the "gold standard." A novel combined-catheter, composed of a reformed triple-lumen catheter with a microtube inserted within its central cavity, was used in the novel-catheter group. A traditional triple-lumen catheter to monitor central venous pressure plus another single-lumen catheter to monitor left atrial pressure were used in the traditional-method group. MEASUREMENTS AND MAIN RESULTS: The novel combined-catheter could accurately monitor left atrial pressure and central venous pressure. Pressure values measured by the novel catheter correlated well with the gold standard (left atrial pressure, R = 0.98; central venous pressure, R = 0.99). Bland-Altman analyses revealed good agreement between pressures measured by the novel catheter and the gold standard. The absolute value of maximum difference was 0.67 mm Hg for left atrial pressure and 0.33 mm Hg for central venous pressure, which are acceptable in clinical practice. Left atrial pressure-monitoring catheter displaced into the right atrium occurred significantly less frequently in the novel-catheter group when compared with the traditional-method group (5 and 12 cases, respectively). CONCLUSIONS: This novel combined-catheter was safe and reliable at monitoring left and right atrial pressures, and infusion involved only one catheter without the disadvantages of the traditional method. This new novel method may be particularly useful in pediatric open-heart surgery.

Dexmedetomidine improves lung compliance in patients undergoing lateral decubitus position of shoulder arthroscopy: A randomized controlled trial.

BACKGROUND: The improvement of oxygenation and pulmonary mechanics in patients under general anesthesia can be achieved by dexmedetomidine (DEX) infusion. However, its role in patients undergoing lateral supine shoulder arthroscopy has not been thoroughly studied. This study aimed to evaluate the effect of DEX on lung compliance in patients undergoing shoulder arthroscopic surgery in a lateral decubitus position. METHODS: The patients who underwent lateral recumbent shoulder arthroscopy under general anesthesia were randomly divided into the DEX group (group D) and the control group (group N). At the start of the trial, group D was given 0.5 µg/kg/hours continuous pumping until 30 minutes before the end of anesthesia; Group N was injected with normal saline at the same volume. The patients were recorded at each time point after intubation: supine position for 5 minutes (T0), lateral position for 5 minutes (T1), lateral position for 1 hour (T2), lateral position for 2 hours (T3), airway peak pressure, platform pressure, dynamic lung compliance, and static lung compliance, etc. RESULTS: At the end of the drug infusion, the DEX group showed significant improved pulmonary mechanics and higher lung compliance than the control group. Compared with group N, group D's heart rate and mean arterial pressure were lower at all time points; there was no statistical difference in Tidal volume and Pressure end-tidal carbon dioxide data at each time point in Group D. CONCLUSION: DEX can improve lung compliance and reduce airway pressure and platform pressure of patients undergoing shoulder arthroscopy in the lateral position under general anesthesia.

General anesthesia with nerve blocks for a patient with femoral fracture and essential thrombocythemia: a case report.

Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm characterized by an abnormal increase in platelets. We report a female patient with a severe femoral fracture and ET who underwent the femoral intramedullary fracture fixation procedure. Her past medical history included hypertension and ET. On the second day of hospitalization, her platelet count was 922 × 109/L. In our case, general anesthesia combined with a femoral nerve block and a lateral femoral cutaneous nerve block were used when the platelet count was within normal range. After surgery, the platelet count increased to 979 × 109/L despite using anticoagulant drugs and hydroxyurea. The postoperative recovery went well after the follow-up of this patient. In this case report, we provide our experience of anesthesia management and review the progress of relevant literature to provide some reference.

Effect of tracheal intubation on postoperative complications in patients with pulmonary hypertension combined with non-cardiothoracic, non-obstetric surgery.

Endotracheal intubation can be associated with certain complications in certain group of patients. However, the relationship between endotracheal intubation and postoperative complications is unclear in patients with pulmonary hypertension (PHTN). This study evaluated the relationship between endotracheal intubation and postoperative complications in non-cardiothoracic and non-obstetric surgery patients with PHTN. A secondhand analysis of non-cardiothoracic, non-obstetric procedures was performed on patients with PHTN between 2007 and 2013 in a hospital at the University of Washington. Multivariable logistic regression analyses were used to calculate the adjusted odds ratios to estimate the association between anesthesia and 30-day postoperative complications. Interaction and stratified analyses were conducted according to the American Society of Anesthesiologists score (ASA), smoking, hypertension, and open surgical approach. A total of 573 patients were included in this study, and the mean age was 60.3; 54% were male. In a multivariate regression model for patients with non-cardiothoracic, non-obstetric surgery combined with PHTN, the risk of 30-day postoperative complications was higher in the tracheal intubation group than in patients with non-intubated anesthesia after adjusting for potential covariates (adjusted odds ratio = 2.47; 95% CI, 1.28-4.78). However, there was no significant difference in postoperative mortality between these groups. Statistical analysis showed no interaction between the variables of tracheal intubation and 30-day postoperative complications. In this study, we found that tracheal intubation anesthesia is associated with increased risk of 30-day postoperative complications in PHTN patients undergoing non-cardiothoracic, non-obstetric surgery. Further studies are needed to confirm our findings.

Comparison of the synergistic effects of sevoflurane and desflurane on muscle relaxant vecuronium in laparoscopic colon cancer surgery.

Sevoflurane and desflurane are commonly used inhalation anesthetics in clinical practice. This study compared the synergistic effects of sevoflurane and desflurane on the muscarinic agent vecuronium in laparoscopic colon cancer surgery. The aim of this study was to compare sevoflurane and desflurane in a synergistic effect on the muscle relaxant vecuronium in laparoscopic colon cancer surgery. Sixty patients undergoing elective laparoscopic radical resection of colon cancer were randomly divided into sevoflurane (n = 30) and desflurane (n = 30) groups. After anesthesia and successful tracheal intubation, patients in both groups were maintained with combined remifentanil. Muscle relaxant effects were monitored in both groups using a muscle relaxant monitor (train of stimuli-Watch), the onset time, T1 and T2 recovery time, and muscle relaxant dosage of vecuronium were observed. Hemodynamic changes were observed in both groups, and the dosage of vasoactive drugs was recorded. The quality of recovery of the patients was evaluated using the Mini-Mental State Examination (MMSE) and the discharge from the Aldrete score criteria. There was no significant difference in the onset time of vecuronium between the two groups (P > .05). The desflurane group's T1 and T2 recovery times were later than that of the sevoflurane group. The dosage of vecuronium was statistically significantly less than that in the sevoflurane group (P < .05); the extubation time in the desflurane group was statistically significantly longer than that in the sevoflurane group (P < .05). There were no significant differences in preoperative and intraoperative mean arterial pressure, heart rate, ephedrine and atropine dosage, MMSE score, and Aldrete score between the 2 groups (P > .05). Compared with sevoflurane, desflurane has a stronger synergistic effect on the muscle relaxant of vecuronium without increasing the incidence of cardiovascular adverse reactions and affecting patient recovery.

Effect of dexmedetomidine on intrapulmonary shunt in patients with sevoflurane maintained during one-lung ventilation: A case-control study.

BACKGROUND: The effects of dexmedetomidine on the circulatory system are complex. It is difficult to predict its effects on intrapulmonary shunts and hypoxic pulmonary vasoconstriction in patients with one-lung ventilation. This study aimed to investigate the effect of dexmedetomidine on intrapulmonary shunt in patients with sevoflurane during one-lung ventilation. METHODS: Forty patients requiring thoracoscopic lobectomy were randomly divided into the dexmedetomidine group (Group D, n = 20) and the normal saline group (Group N, n = 20). The arterial partial pressure of oxygen (PaO2), pulmonary shunt fraction (Qs/Qt), mean end-tidal sevoflurane concentration, mean arterial pressure, and heart rate were compared between the 2 groups at 3 time points: (i) after 5 minutes of two-lung ventilation (T0), (ii) after 30 minutes of one-lung ventilation (OLV) (T1), and (iii) after 45 minutes of OLV (T2). The dosage of sevoflurane from the beginning of OLV to T2 was calculated. RESULTS: There were no significant differences in age, body mass index, and FEV1/FVC between Groups D and N (P > .05). At T0, T1, and T2, the PaO2 levels of Group D and Group N were similar (P > .05), and the PaO2 levels of Group D and Group N decreased after OLV. The Qs/Qt level of Groups D and N were similar at T0 (P > .05), and the level of Groups D and N at T1 and T2 was higher than that at T0. The Qs/Qt of Group D was statistically significantly lower than that of Group N at T1 and T2 (P < .05). CONCLUSION: Compared with the control group, we found that dexmedetomidine can reduce the intrapulmonary shunt fraction and improve the body's status during OLV.

Transcriptome Analysis of Beet Webworm Shows That Histone Deacetylase May Affect Diapause by Regulating Juvenile Hormone.

The beet webworm (Loxostege sticticalis L.) is an important agricultural pest and can tolerate harsh environmental conditions by entering diapause. The diapause mechanism of beet webworm is unknown. Therefore, we conducted a transcriptomic study of the process from diapause induction to diapause release in beet webworms. The results revealed 393 gene modules closely related to the diapause of beet webworm. The hub gene of the red module was the HDACI gene, which acts through histone deacetylase (HDAC) enzymes. HDAC enzyme activity was regulated by the light duration and influenced the JH content under induced beet webworm diapause conditions (12 h light:12 h dark). In addition, transcriptomic data suggested that circadian genes may not be the key genes responsible for beet webworm diapause. However, we showed that the photoperiod affects HDAC enzyme activity, and HDAC can regulate the involvement of JH in beet webworm diapause. This study provided a new module for studying insect diapause and links histone acetylation and diapause at the transcriptome level.

High Expression of PRSS3 Indicates Unfavorable Clinical Outcomes in Colon Adenocarcinoma.

INTRODUCTION: Serine proteases have been implicated as key drivers and facilitators of cancer malignancy. Protease, serine, 3 (PRSS3), which belongs to the serine proteases family, is reported to be abundantly expressed in a variety of types of tumor and contributes to the initiation and development of cancers. However, the clinical role of PRSS3 in colon adenocarcinoma (CAC) was not clarified yet. In the present study, we explored the potential effect of PRSS3 in CAC and whether it is related to the poor survival of CAC patients. MATERIALS AND METHODS: The mRNA and protein levels of PRSS3 were examined in CAC samples and connective noncancerous colon samples through quantitative real-time polymerase chain reaction assay and immunohistochemistry staining. Univariate and multivariate analyses were performed to estimate the prognostic role of PRSS3 in enrolled CAC patients. RESULTS: PRSS3 expression in CAC samples was significantly increased compared with connective noncancerous samples. Moreover, a higher level of PRSS3 was found to be correlated with the larger tumor size, advanced T stage, and positive lymph node metastasis. In addition, PRSS3 was also defined as an unfavorable prognosis factor for CAC patients. CONCLUSIONS: High expression of PRSS3 was significantly related to the unfavorable clinical features and poor prognosis in CAC patients. It suggested that PRSS3 might serve as a novel prognostic indicator and potential drug target for CAC treatment.

Study on the preparation and flame retardant properties of an eco-friendly potassium-calcium carrageenan fiber.

Potassium-calcium carrageenan fibers were prepared in an eco-friendly fashion by wet spinning method. The forming process and flame retardant properties of this fiber compared with the traditional barium carrageenan fibers were studied in this paper. The results showed that the potassium ions were combined with the sulfate group in the carrageenan by ion bonding that made the potassium-calcium carrageenan fibers form a gel structure, which was a relative loose spatial network, while barium ions reacted with the sulfate groups of carrageenan to induce barium carrageenan fibers form a precipitated structure, which was a relative close spatial network. The limiting oxygen index, cone calorimeter, thermogravimetric analysis and pyrolysis-gas chromatography-mass spectrometry tests implied that K+-Ca2+ affected the pyrolysis behavior of potassium-calcium carrageenan fibers and catalyzed it to produce different pyrolysis products from Ba2+ in barium carrageenan fibers. In addition, the pyrolysis mechanism of potassium-calcium carrageenan fibers was elucidated in this paper.