Risk factors of more severe hypotension after spinal anesthesia for cesarean section.

BACKGROUND: The aim of this study was to examine the risk factors associated with the use of vasopressors to prevent hypotension that occurs after spinal anesthesia during cesarean section. Although the prophylactic use of vasopressors is already suggested as routine care in many parts of the world, the occurrence of spinal anesthesia-induced hypotension (SAIH) is still common in parturients. METHODS: This retrospective study included parturients receiving elective cesarean deliveries under spinal anesthesia from April 2016 to March 2020. Risk factors related to ephedrine dosage were analyzed using a hurdle model, and risk factors related to SAIH were further analyzed with logistic regression. RESULTS: Five risk factors, namely maternal body mass index (BMI, p < 0.001), baseline systolic blood pressure (SBP, p < 0.001), baseline heart rate (HR, p = 0.047), multiparity ( p = 0.003), and large fetal weight ( p = 0.005) were significantly associated with the requirement for ephedrine. Furthermore, a higher ephedrine dosage was significantly associated with maternal BMI ( p < 0.001), baseline SBP ( p < 0.001), baseline HR ( p < 0.001), multiparity ( p = 0.027), large fetal weight ( p = 0.030), maternal age ( p = 0.009), and twin pregnancies ( p < 0.001). Logistic regression analysis also showed that the same five risk factors-maternal BMI ( p = 0.030), baseline SBP ( p < 0.001), baseline HR ( p < 0.001), multiparity ( p < 0.001), and large fetal weight ( p < 0.001)-were significantly associated with SAIH, even in cases where vasopressors were administered. CONCLUSION: These findings can be useful for clinicians when deciding the dose of prophylactic ephedrine or phenylephrine to prevent SAIH.

Group-based trajectory analysis of acute pain after spine surgery and risk factors for rebound pain.

Background: This retrospective study was designed to explore the types of postoperative pain trajectories and their associated factors after spine surgery. Materials and methods: This study was conducted in a single medical center, and patients undergoing spine surgery with intravenous patient-controlled analgesia (IVPCA) for postoperative pain control between 2016 and 2018 were included in the analysis. Maximal pain scores were recorded daily in the first postoperative week, and group-based trajectory analysis was used to classify the variations in pain intensity over time and investigate predictors of rebound pain after the end of IVPCA. The relationships between the postoperative pain trajectories and the amount of morphine consumption or length of hospital stay (LOS) after surgery were also evaluated. Results: A total of 3761 pain scores among 547 patients were included in the analyses and two major patterns of postoperative pain trajectories were identified: Group 1 with mild pain trajectory (87.39%) and Group 2 with rebound pain trajectory (12.61%). The identified risk factors of the rebound pain trajectory were age less than 65 years (odds ratio [OR]: 1.89; 95% CI: 1.12-3.20), female sex (OR: 2.28; 95% CI: 1.24-4.19), and moderate to severe pain noted immediately after surgery (OR: 3.44; 95% CI: 1.65-7.15). Group 2 also tended to have more morphine consumption (p < 0.001) and a longer length of hospital stay (p < 0.001) than Group 1. Conclusion: The group-based trajectory analysis of postoperative pain provides insight into the patterns of pain resolution and helps to identify unusual courses. More aggressive pain management should be considered in patients with a higher risk for rebound pain after the end of IVPCA for spine surgery.

A Tapered Cuff Tracheal Tube Decreases the Need for Cuff Pressure Adjustment After Surgical Retraction During Anterior Cervical Spine Surgery: A Randomized Controlled, Double-Blind Trial.

Background: Surgical retraction to expose the vertebrae during anterior cervical spine surgery increases tracheal tube cuff pressure and may worsen postoperative sore throat and dysphonia. This randomized double-blind study investigated the effect of cuff shape on intraoperative cuff pressure and postoperative sore throat and dysphonia. Methods: Eighty patients were randomized to tracheal intubation with a tapered cuff or a conventional cylindrical high-volume low-pressure cuff (control) during anesthesia. Intraoperative cuff pressures were compared. The primary outcome was the incidence of pressure adjustment needed when the cuff pressure increased to > 25 mm Hg after surgical retraction. The secondary outcome was the incidence of postoperative sore throat and dysphonia. Results: The incidence of pressure adjustment after surgical retraction was significantly lower in the tapered group than in the control group (13% vs. 48%; P = 0.001; relative risk reduction, 74%). The median [interquartile range (IQR)] cuff pressure (mm Hg) was significantly lower for the tapered cuff than for the control cuff before surgical retraction [9 (7-12) vs. 12 (10-15); P < 0.001] and after retraction [18 (15-23) vs. 25 (18-31); P = 0.007]. The median (IQR) postoperative dysphonia score assessed by a single speech-language pathologist was lower in the tapered group than in the control group [4 (3-6) vs. 5.5 (5-7); P = 0.008]. Conclusion: A tapered cuff tracheal tube decreased the need for the adjustment of cuff pressure after surgical retraction during anterior cervical spine surgery, thereby avoiding intraoperative pressure increase. It also has a better outcome in terms of dysphonia. Clinical Trial Registration: [www.clinicaltrials.gov], identifier [NCT04591769].

Cervical spine immobilization does not interfere with nasotracheal intubation performed using GlideScope videolaryngoscopy: a randomized equivalence trial.

GlideScope-assisted nasotracheal intubation (NTI) has been proposed as an alternative to difficult orotracheal intubation for critical patients or those under cervical immobilization. We evaluated the difficulty of performing NTI using GlideScope under cervical orthosis. A total of 170 patients scheduled for elective cervical spinal surgery that required NTI were randomized to receive cervical immobilization using a cervical collar (collar group) or no cervical immobilization at all (control group) before anesthetic induction (group assignment at 1:1 ratio). All NTI during anesthetic induction were performed using the GlideScope. The primary outcome was time to intubation. The secondary outcomes were ease of intubation, including the necessity of auxiliary manipulations to assist intubation, and the nasotracheal intubation difficulty scale (nasoIDS). An exploratory analysis identified morphometric parameters as predictors of time to intubation, the necessity of auxiliary manipulations, and a nasoIDS score ≥ 4. For time to intubation, the mean difference (collar group-control) was - 4.19 s, with a 95% confidence interval (CI) of - 13.9 to 5.52 that lay within our defined equivalence margin of 16 s. Multivariate regressions precluded the association of cervical immobilization with a necessity for auxiliary manipulations (adjusted odds ratio [aOR] 0.53, 95% CI [0.26-1.09], P = 0.083) and a nasoIDS ≥ 4 (aOR 0.94 [0.84-1.05], P = 0.280). Among all morphometric parameters, the upper lip bite test class was predictive of a longer time to intubation (all analyses relative to class 1, 14 s longer for class 2, P = 0.032; 24 s longer for class 3, P = 0.070), increased necessity for auxiliary manipulation (aOR 2.29 [1.06-4.94], P = 0.036 for class 2; aOR 6.12 [1.04-39.94], P = 0.045 for class 3), and nasoIDS ≥ 4 (aOR 1.46 [1.14-1.89], P = 0.003 for class 3).The present study demonstrated that GlideScope achieved NTI in patients with or without cervical immobilization equivalently with respect to intubation time and ease.

Group-based trajectory analysis of postoperative pain in epidural analgesia for video-assisted thoracoscopic surgery and risk factors of rebound pain.

BACKGROUND: The current study aimed to investigate the patterns of postoperative pain trajectories over time and their associated risk factors in patients receiving video-assisted thoracoscopic surgery (VATS) and epidural analgesia (EA) for non-small cell lung cancer (NSCLC). METHODS: This retrospective study was conducted at a tertiary medical center and included patients undergoing VATS for stage I NSCLC between 2011 and 2015. Maximal pain intensity was recorded daily during the first postoperative week. Group-based trajectory analysis was performed to categorize variations in pain scores over time. Associations between pain trajectory classification and amount of EA administered and length of hospital stay (LOS) after surgery were also evaluated. RESULTS: A total of 635 patients with 4647 pain scores were included in the analysis, and 2 postoperative pain trajectory groups were identified: group 1, mild pain trajectory (78%); and group 2, rebound pain trajectory (22%). Risk factors for rebound pain trajectory were a surgical time longer than 3 hours (odds ratio [OR], 1.97; 95% CI, 1.27-3.07), female sex (OR, 1.62; 95% CI, 1.04-2.53), and higher pain score on postoperative day 0 (OR, 1.21; 95% CI, 1.08-1.36; linear effect). Although group 2 had a longer LOS (p < 0.001), they did not receive more EA than group 1 (p = 0.805). CONCLUSION: Surgical time, sex, and pain intensity after surgery were major determinants of rebound pain trajectory, and more aggressive pain control strategies should be considered in high-risk patients.

A systematic review and meta-analysis of the comparison of performance among step-tip, split-tip, and symmetrical-tip hemodialysis catheters.

OBJECTIVE: Patients with end-stage renal disease need vascular access to ensure sufficient blood flow during hemodialysis (HD). Patients who are poor candidates for arteriovenous access creation require long-term catheter placement. Problems such as dialysate recirculation, thrombosis, catheter-related infections, and malfunction can occur with HD catheters. Different tip designs (step, split, and symmetrical) have been developed to ameliorate the catheter-related problems. The aim of the study was to compare the efficacy and safety of split-tip, step-tip, and symmetrical-tip HD catheters. METHODS: The PubMed, Embase, Cochrane Library, and Scopus databases and the ClinicalTrials.gov registry were searched for studies published before November 2017. Studies comparing the clinical and rheologic outcomes of step-, split-, or symmetrical-tip catheters in patients undergoing HD were included in this meta-analysis. We conducted meta-analyses using random-effects models. The primary outcomes were catheter survival time and incidence of functioning catheters. The secondary outcomes were delivered blood flow rate, blood recirculation rate, and incidence of catheter-related complications. RESULTS: Seven randomized controlled trials and one retrospective study with a total of 988 patients were included. No significant differences were observed in the delivered blood flow rate (weighted mean difference, -5.37 mL/min; 95% confidence interval [CI], -23.75 to 13.02), incidence of catheter-related infections (risk ratio [RR], 1.18; 95% CI, 0.63-2.22), or incidence of catheter-related thrombosis (RR, 1.29; 95% CI, 0.64-2.59) between step-tip catheters and advanced (both split-tip and symmetrical-tip) catheters. Moreover, a meta-analysis of the incidence of functioning catheters at 1 month, 6 months, and 12 months revealed that the outcome of step-tip catheter use was better than that of split-tip catheter use, but with a significant difference only at 6 months (RR, 1.22; 95% CI, 1.02-1.46). CONCLUSIONS: None of the catheter types exhibited unique features that can enhance their suitability for application. Hence, catheters can be selected by also considering different factors, including costs, ease of procedures, expertise of the clinician, and education and preference of the patient.

A consensus envelope protein domain III can induce neutralizing antibody responses against serotype 2 of dengue virus in non-human primates.

We have previously demonstrated that vaccination with a subunit dengue vaccine containing a consensus envelope domain III with aluminum phosphate elicits neutralizing antibodies against all four serotypes of dengue virus in mice. In this study, we evaluated the immunogenicity of the subunit dengue vaccine in non-human primates. After vaccination, monkeys that received the subunit vaccine with aluminum phosphate developed a significantly strong and long-lasting antibody response. A specific T cell response with cytokine production was also induced, and this correlated with the antibody response. Additionally, neutralizing antibodies against serotype 2 were detected in two of three monkeys. The increase in serotype-2-specific antibody titers and avidity observed in these two monkeys suggested that a serotype-2-biased antibody response occurs. These data provide evidence that a protective neutralizing antibody response was successfully elicited in non-human primates by the dengue subunit vaccine with aluminum phosphate adjuvant.

Dengue-1 envelope protein domain III along with PELC and CpG oligodeoxynucleotides synergistically enhances immune responses.

The major weaknesses of subunit vaccines are their low immunogenicity and poor efficacy. Adjuvants can help to overcome some of these inherent defects with subunit vaccines. Here, we evaluated the efficacy of the newly developed water-in-oil-in-water multiphase emulsion system, termed PELC, in potentiating the protective capacity of dengue-1 envelope protein domain III. Unlike aluminum phosphate, dengue-1 envelope protein domain III formulated with PELC plus CpG oligodeoxynucleotides induced neutralizing antibodies against dengue-1 virus and increased the splenocyte secretion of IFN-γ after in vitro re-stimulation. The induced antibodies contained both the IgG1 and IgG2a subclasses. A rapid anamnestic neutralizing antibody response against a live dengue virus challenge was elicited at week 26 after the first immunization. These results demonstrate that PELC plus CpG oligodeoxynucleotides broaden the dengue-1 envelope protein domain III-specific immune responses. PELC plus CpG oligodeoxynucleotides is a promising adjuvant for recombinant protein based vaccination against dengue virus.

A novel single-dose dengue subunit vaccine induces memory immune responses.

To protect against dengue viral infection, a novel lipidated dengue subunit vaccine was rationally designed to contain the consensus amino acid sequences derived from four serotypes of dengue viruses. We found that the lipidated consensus dengue virus envelope protein domain III (LcED III) is capable of activating antigen-presenting cells and enhancing cellular and humoral immune responses. A single-dose of LcED III immunization in mice without extra adjuvant formulation is sufficient to elicit neutralizing antibodies against all four serotypes of dengue viruses. In addition, strong memory responses were elicited in mice immunized with a single-dose of LcED III. Quick, anamnestic neutralizing antibody responses to a live dengue virus challenge were elicited at week 28 post-immunization. These results demonstrate the promising possibility of a future successful tetravalent vaccine against dengue viral infections that utilizes one-dose vaccination with LcED III.

Development and application of a milli-whistle for use in gas chromatography detection.

A simple milli-whistle was developed for the use in GC (gas chromatography) detection, in which, compared to a thermal conductivity detector (TCD), 1 order of magnitude superior sensitivity can be obtained. The milli-whistle can be connected to the outlet of a GC capillary. The gas and makeup gas passing through the capillary produces a sound as it passes through the milli-whistle (i.e., the gas of the GC eluate). The sound can easily be detected by a microphone, which, after a Fourier transform (FT) by means of a LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench) built-in program, a very sharp frequency peak (full width at half-maximum, approximately 1.6 Hz) can be simultaneously observed. As a result, GC elutes can be qualitatively determined on the basis of their retention times, and a quantitative analysis can be achieved on the basis of the frequency shifts. When the makeup and carrier gases used were nitrogen, in the case of gas samples, including hydrogen, helium, argon, and carbon dioxide, the limits of detection were found to be approximately 3 microL/each injection; in the case of liquid samples, including methanol, cyclohexane, tetrahydrofuran, hexane, and acetone, the limits of detection were determined to be approximately 10 microg/each injection, respectively. When the gases were changed to hydrogen, the limits of detection were dramatically improved. When acetone was selected as the model sample, a linear relationship was found in the range of 0.2-200 microg/injection.

IL-6-transfected tumor cells modulate the status of CD8(+) and CD4(+) T cells to control tumor growth.

IL-6 is a proinflammatory cytokine secreted by tumor cells and immune cells to affect the development of cancer. This study demonstrates the effects of tumor-derived IL-6 on the malignancy of tumor cells and tumor immunity. The tumor cell line, EG7, was transfected with a mammalian expression vector encoding the full length of murine IL-6 to mimic IL-6-secreting tumor cells. Two IL-6 transfectants with low and high IL-6 production were compared in vitro and in vivo. While the in vitro proliferation rates of both transfectants and the parental line were similar, high expression of IL-6 induced a significant reduction in tumor growth in vivo. Concomitantly, there was an increase in IFN-gamma positive tumor-infiltrating lymphocytes and a decrease in the suppressive CD4(+)CD25(+)FoxP3(+) population. These results demonstrate the direct effects of tumor-derived IL-6 on cancer development and the induction of tumor immunity.

A novel dengue vaccine candidate that induces cross-neutralizing antibodies and memory immunity.

A novel dengue vaccine candidate comprised of a consensus dengue virus envelope protein domain III (cED III) was developed to fight against dengue virus infection. The amino acid sequence of this novel cED III was obtained by alignment of amino acid sequences from different isolates of the four serotypes of dengue viruses. A proof-of-concept study demonstrated that BALB/c mice immunized with the recombinant cED III developed neutralizing antibodies against all serotypes of dengue virus. Moreover, formulation of recombinant cED III with aluminum phosphate could induce long-lasting antibody responses and anamnestic neutralizing antibody responses following challenge with dengue virus at week 28 after priming. These results demonstrate the possibility of developing a single tetravalent vaccine against dengue viral infections.