Indirect laryngoscopy is more effective than direct laryngoscopy when tracheal intubation is performed by novice operators: a systematic review, meta-analysis, and trial sequential analysis.

PURPOSE: We sought to perform a systematic review and meta-analysis to determine whether indirect laryngoscopy has an advantage over direct laryngoscopy in terms of the tracheal intubation rate, glottic visualization, and intubation time when used by novice operators. METHODS: We extracted adult prospective randomized trials comparing tracheal intubation with indirect vs direct laryngoscopy in novice operators from electronic databases. We extracted the following data from the identified studies: success rate, glottic visualization, and intubation time. Data from each trial were combined via a random-effects model to calculate the pooled relative risk (RR) or weighted mean difference (WMD) with a 95% confidence interval (CI). We also performed a trial sequential analysis. RESULTS: We included 15 articles (17 trials) comprising 2,290 patients in the systematic review. Compared with the direct laryngoscopy, indirect laryngoscopy improved success rate (RR, 1.15; 95% CI, 1.07 to 1.24; P = 0.0002; I2 = 88%), glottic visualization (RR, 1.76; 95% CI, 1.36 to 2.28; P < 0.001; I2 = 85%), and intubation time (WMD, -9.06 sec; 95% CI, -16.4 to -1.76; P = 0.01; I2 = 98%) in tracheal intubation. Trial sequential analysis showed that the total sample size was sufficient to analyze the success rate and intubation time. CONCLUSION: In this systematic review, we found that the tracheal intubation success rate, glottic visualization, and intubation time were improved when novice operators used indirect laryngoscopy rather than direct laryngoscopy. Trial sequential analysis results indicated that the sample size was sufficient for examining the success rate and intubation time. STUDY REGISTRATION: PROSPERO (CRD42022309045); first registered 4 September 2022.

RéSUMé: OBJECTIF: Nous avons cherché à réaliser une revue systématique et une méta-analyse pour déterminer si la laryngoscopie indirecte présente un avantage par rapport à la laryngoscopie directe en termes de taux de succès d'intubation trachéale, de visualisation glottique et de temps d'intubation lorsqu'elle est utilisée par des opératrices et opérateurs novices. MéTHODE: Nous avons extrait des études randomisées prospectives chez l'adulte comparant l'intubation trachéale avec une laryngoscopie indirecte vs directe réalisée par des opérateurs et opératrices novices à partir de bases de données électroniques. Nous avons extrait les données suivantes des études identifiées : taux de succès, visualisation glottique et temps d'intubation. Les données de chaque étude ont été combinées au moyen d'un modèle à effets aléatoires pour le calcul du risque relatif (RR) groupé ou de la différence moyenne pondérée (DMP) avec un intervalle de confiance (IC) de 95 %. Nous avons également réalisé une analyse séquentielle des études. RéSULTATS: Nous avons inclus 15 articles (17 études) portant sur 2290 patient·es dans notre revue systématique. Par rapport à la laryngoscopie directe, la laryngoscopie indirecte a amélioré le taux de succès (RR, 1,15; IC 95 %, 1,07 à 1,24; P = 0,0002; I2 = 88 %), la visualisation glottique (RR, 1,76; IC 95 %, 1,36 à 2,28; P < 0,001; I2 = 85 %), et le temps d'intubation (DMP, −9,06 s; IC 95 %, −16,4 à −1,76; P = 0,01; I2 = 98 %) pour l'intubation trachéale. L'analyse séquentielle des études a montré que la taille totale de l'échantillon était suffisante pour analyser le taux de succès et le temps d'intubation. CONCLUSION: Dans cette revue systématique, nous avons constaté que le taux de succès de l'intubation trachéale, la visualisation glottique et le temps d'intubation étaient améliorés lorsque les opératrices et opérateurs novices utilisaient la laryngoscopie indirecte plutôt que la laryngoscopie directe. L'analyse séquentielle des études a montré que la taille totale de l'échantillon était suffisante pour analyser le taux de succès et le temps d'intubation. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42022309045); première inscription le 4 septembre 2022.

Sodium-glucose cotransporter 2 inhibitor-associated perioperative ketoacidosis: a systematic review of case reports.

Although the recommended preoperative cessation period for sodium-glucose cotransporter 2 inhibitors (SGLT2is) changed in 2020 (from 24 h to 3-4 days preoperatively) to reduce the risk of SGLT2i-associated perioperative ketoacidosis (SAPKA), the validity of the new recommendation has not been verified. Using case reports, we assessed the new recommendation effectiveness and extrapolated precipitating factors for SAPKA. We searched electronic databases up to June 1, 2022 to assess SAPKA (blood pH < 7.3 and blood or urine ketone positivity within 30 days postoperatively in patients taking SGLT2i). We included 76 publications with 99 cases. The preoperative SGLT2i cessation duration was reported for 59 patients (59.6%). In all cases with available cessation periods, the SGLT2is were interrupted < 3 days preoperatively. No SAPKA cases with > 2-day preoperative cessation periods were found. Many case reports lack important information for estimating precipitating factors, including preoperative SGLT2i cessation period, body mass index, baseline hemoglobin A1c level, details of perioperative fluid management, and type of anesthesia. Our study suggested that preoperative SGLT2i cessation for at least 3 days could prevent SAPKA. Large prospective epidemiologic studies are needed to identify risk factors for SAPKA.

Airtraq® versus GlideScope® for tracheal intubation in adults: a systematic review and meta-analysis with trial sequential analysis.

PURPOSE: In recent years, various types of indirect laryngoscopes have been developed. Nevertheless, no conclusions have been drawn about which type of indirect laryngoscope is most effective for tracheal intubation. We performed a systematic review and meta-analysis to determine whether the Airtraq® or the GlideScope® is more effective for tracheal intubation. METHODS: We extracted studies of adult prospective randomized trials comparing tracheal intubation between the Airtraq and GlideScope. An electronic database was used to extract the studies included in our meta-analysis. We extracted the following data from the identified studies: success rate, glottic visualization, and intubation time. Data from each trial were combined via a random-effects model for calculation of pooled relative risk (RR) or weighted mean difference (WMD) with a 95% confidence interval (CI). We also performed trial sequential analysis. RESULTS: We included eight trials comprising 571 patients for review. Compared with the GlideScope, Airtraq did not improve success rate, glottic visualization, or intubation time in tracheal intubation (success rate: RR, 0.98; 95% CI, 0.91 to 1.05; P = 0.58; I2 = 65%; glottic visualization: RR, 1.07; 95% CI, 0.88 to 1.29; P = 0.69; I2 = 64%; and intubation time: WMD, 1.4 seconds ; 95% CI, -6.2 to 9.1; P = 0.72; I2 = 96%). The quality of evidence was graded as "very low." Trial sequential analysis showed that total sample size did not reach the required information size for all parameters. CONCLUSION: In this meta-analysis, use of the Airtraq indirect laryngoscope did not result in improved success rate, glottic visualization, or intubation time in tracheal intubation compared with the GlideScope. Trial sequential analysis suggests that further studies are necessary to confirm these findings.

RéSUMé: OBJECTIF: Ces dernières années, différents types de laryngoscopes indirects ont été mis au point. Néanmoins, aucune conclusion n'a été tirée sur le type de laryngoscope indirect le plus efficace pour l'intubation trachéale. Nous avons réalisé une revue systématique et une méta-analyse pour déterminer quel dispositif était le plus efficace pour l'intubation trachéale, soit l'Airtraq® ou le GlideScope®. MéTHODE: Nous avons extrait les études portant sur les essais randomisés prospectifs chez l'adulte comparant l'intubation trachéale avec l'Airtraq ou le GlideScope. Une base de données électronique a été utilisée pour extraire les études incluses dans notre méta-analyse. Nous avons extrait les données suivantes des études identifiées : taux de réussite, visualisation glottique et temps d'intubation. Les données de chaque étude ont été combinées au moyen d'un modèle à effets aléatoires pour le calcul du risque relatif (RR) groupé ou de la différence moyenne pondérée (DMP) avec un intervalle de confiance (IC) de 95 %. Nous avons également réalisé une analyse séquentielle des études. RéSULTATS: Nous avons inclus huit études portant sur 571 patients pour notre revue. Par rapport au GlideScope, l'Airtraq n'a pas amélioré le taux de réussite, la visualisation glottique ou le temps d'intubation pour l'intubation trachéale (taux de réussite : RR, 0,98; IC 95 %, 0,91 à 1,05; P = 0,58; I2 = 65 %; visualisation glottique : RR, 1.07; IC 95 %, 0,88 à 1,29; P = 0,69; I2 = 64 %; et temps d'intubation : DMP, 1,4 seconde; IC 95 %, -6,2 à 9,1; P = 0,72; I2 = 96 %). La qualité des données probantes a été classée comme « très faible ¼. L'analyse séquentielle des études a montré que la taille totale de l'échantillon n'atteignait pas la taille d'information requise pour tous les paramètres. CONCLUSION: Selon cette méta-analyse, l'utilisation du laryngoscope indirect Airtraq® n'entraîne pas d'amélioration du taux de réussite, de la visualisation glottique ou du temps d'intubation pour une intubation trachéale par rapport au GlideScope®. L'analyse séquentielle des études suggère que d'autres études sont nécessaires pour confirmer ces résultats.

Comparison of hemostatic effect and safety between epinephrine and tramazoline during nasotracheal intubation: a double-blind randomized trial.

BACKGROUND: Nasal bleeding is the most common complication during nasotracheal intubation (NTI). To reduce nasal bleeding, the nasal mucosa is treated with vasoconstrictors (epinephrine [E] or tramazoline [T]) prior to NTI. This study aimed to determine whether E or T is more effective and safe for reducing nasal bleeding during NTI. METHODS: This study was preregistered on UMIN-CTR after being approved by the IRB of the School of Dentistry at Aichi Gakuin University. Written consent was received from all the patients. Total 206 patients aged 20-70 years and classified as 1-2 on American Society of Anesthesiologists-physical status were scheduled to undergo general anesthesia with NTI. At last, 197 patients were randomly divided into two groups and treated with either E (n = 99; 3 patients were discontinued) or T (n = 98; 2 patient were discontinued). After induction of general anesthesia, each patient's nasal mucosa was treated using either E or T. The E used in this study was BOSMIN® SOLUTION 0.1% (Daiichi-Sankyo Co., Ltd., Tokyo), and the T used in this study was TRAMAZOLIN Nasal Solution 0.118% AFP, (Alfresa Pharma Corporation, Osaka). E was diluted five times according to the package insert (final concentration of E = 0.02%), and T was used in its original solution. After 2 min, NTI was performed via the right nostril. Primary outcome were the presence of nasal bleeding (if bleeding was recognized at the posterior pharyngeal wall via nasal cavity during intubation, it was defined as bleeding) and the degree of bleeding (classified as none, mild, moderate, or severe). Secondary outcomes were arrhythmia, and hemodynamic (mean atrial pressure and heart rate) changes associated with vasoconstrictors. RESULTS: The presence of bleeding was comparable in both groups (12.5%, E; 14.5%, T; P = 0.63). No significant difference between the groups regarding the degree of bleeding (P = 0.78) was observed, with most patients having no bleeding (n = 84, E; n = 82, T). No severe bleeding and no arrhythmias induced by vasoconstrictor were observed in the two groups. CONCLUSIONS: Nasal treatment with E or T shows no difference in nasal bleeding during NTI. Although no arrhythmia associated with E was observed in this study, it has been reported in literature. Therefore, as frequency and degree of nasal bleeding were comparable, nasal treatment with T could reduce the risk of NTI. TRIAL REGISTRATION: UMIN-CTR (Registration No. UMIN000037907 ). Registered (05/09/2019).

Comparison of Hemodynamic Responses to Administration of Vasopressin and Norepinephrine Under General Anesthesia: A Systematic Review and Meta-analysis of Randomized Controlled Trials with Trial Sequential Analysis.

OBJECTIVE: The authors performed a meta-analysis to determine if vasopressin improves hypotension more than norepinephrine under general anesthesia. DESIGN: Meta-analysis. SETTING: Operating room. PATIENTS: Patients who underwent surgery, with general anesthesia. INTERVENTIONS: Administration of vasopressin or norepinephrine in order to increase blood pressure. MEASUREMENTS AND MAIN RESULTS: The primary outcome of this study was to determine if vasopressin increased mean blood pressure more effectively compared with norepinephrine for patients under general anesthesia. The secondary outcome was to see if vasopressin increased heart rate (HR), central venous pressure (CVP), cardiac output (CO), and cardiac index (CI) more significantly compared with norepinephrine under general anesthesia. The authors calculated the weighted mean difference, with 95% confidence interval (CI) using the random-effects model, and calculated the required information size (RIS) by performing trial sequential analysis (TSA). The authors selected 6 studies for analysis. Vasopressin did not improve hypotension compared with norepinephrine under general anesthesia. (weighted mean difference = -0.84 mmHg, 95% CI: -5.90 to 4.23, p = 0.75, Cochran Q = 24.6, I2 = 84%) In TSA, only 35.5% of RIS was achieved. Similarly, vasopressin and norepinephrine were not significantly different in terms of HR, CVP, CO, and CI. In TSA, only 23.7% of the RIS was reached for HR but RIS was almost achieved for CVP and CO. CONCLUSIONS: Vasopressin did not improve hypotension compared with norepinephrine under general anesthesia. The RIS was not reached in TSA, and Grading of Recommendations Assessment, Development and Evaluation is very low. Therefore, further research is needed to reach more robust conclusions.

Asystole Triggered by the Mouth Opening With a Dental Mouth Gag Under General Anesthesia During Pediatric Oral Surgery: Report of a Rare Case.

The trigeminovagal reflex manifests as a sudden onset of bradycardia, hypotension, and cardiac arrest in response to the stimulation of the trigeminal nerve. The incidence of trigeminovagal reflex in maxillofacial surgical procedures is approximately 1.6%. We report a case of asystole in a pediatric patient in whom a dental mouth gag triggered the trigeminovagal reflex during oral surgery. The patient was a 5-year-old boy who was scheduled to undergo extraction of maxillary supernumerary teeth. After tracheal intubation, anesthesia was maintained with sevoflurane and remifentanil. At the beginning of the surgery, his mouth was opened with a dental mouth gag, and electrocardigram showed asystole for 20 seconds. Thereafter, his heart rate spontaneously returned to basal value within 60 seconds. Since sufficient mouth opening was required to conduct the surgery, his mouth was opened again with the gag. When the interincisal distance exceeded about 40 mm, his heart rate suddenly decreased, but spontaneously returned to baseline within 60 second. The subsequent anesthetic course was uneventful.

Effects of intrathecal opioids on cesarean section: a systematic review and Bayesian network meta-analysis of randomized controlled trials.

PURPOSE: We aimed to compare the beneficial and harmful effects of opioids used as adjuncts to local anesthetics in patients undergoing cesarean section under spinal anesthesia. METHODS: We searched electronic databases and ClinicalTrials.gov from their inception until March, 2021 without language restrictions. The primary outcome was the complete analgesia duration (Time to VAS > 0). Data were synthesized using the Bayesian random-effects model. Evidence confidence was evaluated using the Confidence In Network Meta-Analysis. RESULTS: We identified 66 placebo-controlled randomized controlled trials (RCTs) comprising 4400 patients undergoing elective cesarean section. Compared with the placebo, intrathecal opioids (fentanyl, sufentanil, and morphine) significantly prolonged the analgesia duration by 96, 96, and 190 min, respectively (mean difference). Despite morphine ranking first, opioid efficacy was similar; the results were inconsistent with respect to other analgesic outcomes. Except for diamorphine, all opioids were associated with significant increases in the pruritus incidence. Sufentanil and morphine were associated with increases in the respiratory depression incidence. CONCLUSIONS: We confirmed that intrathecal opioids benefit postoperative analgesia. Although morphine seems to be the most appropriate agent, some results were inconsistent, and the evidence confidence was often moderate or low, especially for adverse outcomes. Well-designed RCTs with an evidence-based approach are imperative for determining the most appropriate opioid for cesarean sections.

Anesthetic management in MAO-A and MAO-B deficiency: a case report.

Monoamine oxidase (MAO) deficiency is an X-linked hereditary disease characterized by spontaneous deletion of MAO-A and/or MAO-B on the X chromosome. Here, we describe the first reported case of a patient with MAO-A and MAO-B deficiency managed under general anesthesia in dental treatment. The patient was aged 11 years old when he was scheduled for dental treatment. He was diagnosed with MAO-A and MAO-B deficiency on genetic testing at 2 years of age. He was not given premedication, and standard monitoring with noninvasive blood pressure monitoring, pulse oximetry, and ECG was instituted. We also preemptively prepared a cardioverter-defibrillator. General anesthesia was induced with propofol 46 mg (2 mg/kg), then rocuronium 10 mg (0.4 mg/kg) and remifentanil 0.30 µg/kg/min were administered via separate infusion pumps. Orotracheal intubation was performed without complications. Anesthesia was maintained uneventfully with a continuous infusion of remifentanil 0.15-0.2 µg/kg/min and propofol 5.0-7.0 mg/kg. Fresh gas flow included oxygen and air. End-tidal CO2 concentration was maintained at around 35 mmHg throughout the procedure. We administered sugammadex 92 mg (4 mg/kg) for reversal of neuromuscular blockade and the patient was extubated. We achieved successful anesthetic management without any appreciable clinical signs of fatal arrhythmias in this patient with MAO-A and MAO-B deficiency.

Anesthetic Management of Reversible Cerebral Vasoconstriction Syndrome: A Case Report.

Reversible cerebral vasoconstriction syndrome (RCVS) is a group of disorders characterized by prolonged reversible cerebral vasoconstriction, associated with acute-onset, severe, episodic "thunderclap" headaches with or without other neurologic clinical features. We describe the first reported case, to our knowledge, of a patient with RCVS who was managed under general anesthesia in the field of oral and maxillofacial surgery. A 67-year-old woman with a diagnosis of RCVS made 2 months earlier was scheduled to undergo surgical extraction of the mandibular right third molar. Standard monitoring included noninvasive blood pressure measurement, pulse oximetry, and electrocardiography; a bispectral index (BIS) monitor sensor was placed on her forehead. General anesthesia was induced by target-controlled infusion of propofol to an effect site concentration of 5.0 µg · mL-1, with remifentanil, 0.50 µg · kg-1 per minute, and rocuronium, 40 mg. After tracheal intubation, anesthesia was maintained uneventfully with remifentanil, 0.15 to 0.2 µg · kg-1 per minute, and propofol, 2.0 to 3.0 µg · mL-1, in oxygen and air. The end-tidal carbon dioxide concentration was maintained at 38 to 42 mm Hg. The BIS reading was 40 to 60. Fentanyl, 0.1 mg, and acetaminophen, 750 mg, were administered before the end of surgery for postoperative analgesia. The postoperative course was uneventful, with no headaches or hypertensive complications. We successfully achieved anesthetic management with no appreciable clinical signs of cerebral ischemia or recurrence in a patient with RCVS. We used propofol as the anesthetic agent with BIS monitoring to detect cerebral ischemia. However, there is no definitive evidence of the utility of these measures for the prevention or diagnosis of RCVS, and further study is needed.

Novel identification of the free fatty acid receptor FFAR1 that promotes contraction in airway smooth muscle.

Obesity is one of the major risk factors for asthma. Previous studies have demonstrated that free fatty acid levels are elevated in the plasma of obese individuals. Medium- and long-chain free fatty acids act as endogenous ligands for the free fatty acid receptors FFAR1/GPR40 and FFAR4/GPR120, which couple to Gq proteins. We investigated whether FFAR1 and FFAR4 are expressed on airway smooth muscle and whether they activate Gq-coupled signaling and modulate airway smooth muscle tone. We detected the protein expression of FFAR1 and FFAR4 in freshly dissected native human and guinea pig airway smooth muscle and cultured human airway smooth muscle (HASM) cells by immunoblotting and immunohistochemistry. The long-chain free fatty acids (oleic acid and linoleic acid) and GW9508 (FFAR1/FFAR4 dual agonist) dose-dependently stimulated transient intracellular Ca(2+) concentration ([Ca(2+)]i) increases and inositol phosphate synthesis in HASM cells. Downregulation of FFAR1 or FFAR4 in HASM cells by small interfering RNA led to a significant inhibition of the long-chain free fatty acids-induced transient [Ca(2+)]i increases. Oleic acid, linoleic acid, or GW9508 stimulated stress fiber formation in HASM cells, potentiated acetylcholine-contracted guinea pig tracheal rings, and attenuated the relaxant effect of isoproterenol after an acetylcholine-induced contraction. In contrast, TUG-891 (FFAR4 agonist) did not induce the stress fiber formation or potentiate acetylcholine-induced contraction. These results suggest that FFAR1 is the functionally dominant free fatty acid receptor in both human and guinea pig airway smooth muscle. The free fatty acid sensors expressed on airway smooth muscle could be an important modulator of airway smooth muscle tone.

Effects of sniffing position for tracheal intubation: a meta-analysis of randomized controlled trials.

BACKGROUND: The purpose of this meta-analysis was to validate the efficacy of the sniffing position in the performance of intubation with direct laryngoscopy. METHODS: We searched MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and Web of Science. Six randomized controlled trials comprising 2759 adult participants were analyzed. The DerSimonian-Laird method was used to calculate pooled relative risk (RR) and the 95% confidence interval (CI) of Cormack-Lehane classification, Intubation Difficulty Scale, success rate of the first intubation, and weighted mean difference of intubation time. RESULTS: Compared with the other head positions, the sniffing position did not improve glottic visualization, success rate of the first intubation, or intubation time. However, the sniffing position was significantly associated with better Intubation Difficulty Scale compared with the simple head extension position. (RR,1.28; 95% CI, 1.15-1.42; p<0.0001) CONCLUSIONS: Although patients do not benefit from the sniffing position in terms of glottic visualization, success rate of the first intubation, or intubation time, the sniffing position can still be recommended as the initial head position for tracheal intubation because the sniffing position provides easier intubation conditions.

[Endotracheal intubation in an adult patient fitted with a Leksell frame using a Pentax Airwayscope with a pediatric-type INTLOCK blade (ITL-P)].

Several previous reports have established the Pentax Airwayscope (Pentax AWS, S-100, HOYA-PENTAX, Tokyo, Japan) as an efficient tool for tracheal intubation in adult patients. The Pentax AWS is often successfully used with an INTLOCK blade; to date, however, INTLOCK blades have been released for neonatal and pediatric patients only. In this case, we performed tracheal intubation using a Pentax AWS attached to a pediatric-type INTLOCK blade (ITL-P) in an adult patient fitted with a Leksell Stereotactic frame (Elekta, Sweden). The patient weighed 45 kg and was 154 cm tall, and was scheduled for a tumor biopsy due to glioblastoma in the brain stem. The patient was preoperatively fitted with a Leksell frame on her head. The patient was not premedicated and was monitored with electrocardiography (ECG), noninvasive blood pressure, and pulse oximetry. Following pre-oxygenation, general anesthesia was induced using propofol 4.0 microg x ml with target-controlled infusion and remifentanil 0.25 microg x kg(-1) hr(-1). After loss of consciousness, we administered 30-mg rocuronium boluses. We initially attempted tracheal intubation first using a Macintosh laryngoscope and then a Pentax AWS, but we could not achieve tracheal intubation with either of these instruments. Upon switching to a Pentax AWS with an ITL-P, we successfully achieved tracheal intubation without any complications. Anesthesia was maintained uneventfully with 3.0 microg x ml(-1) propofol and remifentanil 0.10 to 0.25 microg x kg(-1) x hr(-1) in oxygen and air. Further study is needed to facilitate the effective use of the Pentax AWS and the ITL-P in such cases.

Machine learning-based identification of the risk factors for postoperative nausea and vomiting in adults.

Postoperative nausea and vomiting (PONV) is a common adverse effect of anesthesia. Identifying risk factors for PONV is crucial because it is associated with a longer stay in the post-anesthesia care unit, readmissions, and perioperative costs. This retrospective study used artificial intelligence to analyze data of 37,548 adult patients (aged ≥20 years) who underwent surgery under general anesthesia at Tohoku University Hospital from January 1, 2010 to December 31, 2019. To evaluate PONV, patients who experienced nausea and/or vomiting or used antiemetics within 24 hours after surgery were extracted from postoperative medical and nursing records. We create a model that predicts probability of PONV using the gradient tree boosting model, which is a widely used machine learning algorithm in many applications due to its efficiency and accuracy. The model implementation used the LightGBM framework. Data were available for 33,676 patients. Total blood loss was identified as the strongest contributor to PONV, followed by sex, total infusion volume, and patient's age. Other identified risk factors were duration of surgery (60-400 min), no blood transfusion, use of desflurane for maintenance of anesthesia, laparoscopic surgery, lateral positioning during surgery, propofol not used for maintenance of anesthesia, and epidural anesthesia at the lumbar level. The duration of anesthesia and the use of either sevoflurane or fentanyl were not identified as risk factors for PONV. We used artificial intelligence to evaluate the extent to which risk factors for PONV contribute to the development of PONV. Intraoperative total blood loss was identified as the potential risk factor most strongly associated with PONV, although it may correlate with duration of surgery, and insufficient circulating blood volume. The use of sevoflurane and fentanyl and the anesthesia time were not identified as risk factors for PONV in this study.

[Efficacy of Glidescope video laryngoscope in difficult airways: a meta-analysis of randomized controlled trials].

BACKGROUND: Increased evidence indicates that the Glidescope video laryngoscope (GVL) is useful for difficult tracheal intubations. The aim of this meta-analysis was to assess the efficacy of the GVL in difficult tracheal intubations, comparing with that of Macintosh laryngoscopy. METHODS: The systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the PRISMA statement. The relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (CIs) were calculated by the Comprehensive Meta-analysis version 2.2.040 software for dichotomous and continuous outcomes, respectively. RESULTS: Fifteen randomized controlled trials including 860 tracheal intubations by GVL and 860 tracheal intubations by Macintosh laryngoscopy. GVL showed higher success rate (RR 1.065, 95% CI 1.017-1.117, P < 0.008) than does the Macintosh laryngoscope, whereas no difference was found in the duration for instrumentation. CONCLUSIONS: Our meta-analysis showed that GVL has an advantage over Macintosh laryngoscope in respect to the success rate for difficult tracheal intubations.

[Channeled videolaryngoscope: A meta-analysis of randomized controlled trials].

BACKGROUND: The aim of this meta-analysis was to assess the efficacy of the channeled videolaryngoscopes in routine tracheal intubation. METHODS: The systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the PRISMA statement. We included randomized controlled trials in humans comparing Airtraq and Pentax-AWS to Macintosh laryngoscopy regarding the successful first-attempt and time for instrumentation. The relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (CIs) were calculated for dichotomous and continuous outcomes, respectively. RESULTS: We included 20 trials with total of 2,370 patients. The channeled videolaryngoscopes showed higher success rate (RR 1.103, 95%CI 1.042 to 1.167, P <0.00069) and shorter duration for instrumentation (MD-10.873 s, 95%CI-18.588 s to-3.158 s, P< 0.0057). In studies examining novice laryngoscopists, successful first-attempt intubation (RR 1.28, 95%CI 1.14 to 1.45, P<0.000067) and time for instrumentation (MD-22.9 s, 95%CI-29.4 to-16.4, P<0.00001) were improved using the channeled videolaryngoscopes. With respect to experts' hands, there was no difference between the two devices in both of these outcomes for non-difficult intubations, while successful first-attempt intubation was improved for difficult intubations (RR 1.09, 95%CI 1.05 to 1.15, P<0.00011). CONCLUSIONS: Compared to the Macintosh laryngoscopy, channeled videolaryngoscopy offers advantages for novice laryngoscopists, while these benefits are not seen with experts' hands in normal airways. Even with skillful hands, channeled videolaryngoscopy improves the successful first-attempt intubation in difficult intubations.

[Efficacy of Pentax-AWS in difficult airways: a meta-analysis of randomized controlled trials].

BACKGROUND: Increased evidence indicates that the Pentax-AWS (AWS) is useful for difficult airways. The aim of this meta-analysis was to assess the efficacy of the AWS in difficult airways, comparing that of Macintosh laryngoscopy. METHODS: The systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the PRISMA statement. The relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (CIs) were calculated by the Comprehensive Meta-analysis version 2.2.040 software for dichotomous and continuous outcomes, respectively. RESULTS: Eighteen randomized controlled trials, performed in simulated difficult airways (published between 2006, October and 2012, May), included 981 tracheal intubations by AWS and 986 tracheal intubations by Macintosh laryngoscopy. AWS showed higher success rate (RR: 1.220, 95% CI: 1.126 to 1.322, P < 0.00001) and shorter duration for instrumentation (MD: -10.319 s, 95% CI: -14.309 s to -6.328 s, P < 0.00001). CONCLUSIONS: There is considerable evidence that AWS has an advantage over Macintosh laryngoscope in difficult airways.

[Efficacy of videolaryngoscopes for nasotracheal intubation: a meta-analysis of randomized controlled trials].

BACKGROUND: Increased evidence indicates that the videolaryngoscope is useful for nasotracheal intubation. The aim of this meta-analysis is to assess the efficacy of videolaryngoscopes (Glidescope, Airtraq and Pentax-AWS) in nasotracheal intubations, comparing with that of Macintosh laryngoscopy. METHODS: The systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the PRISMA statement. The relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (CIs) were calculated by the Comprehensive Meta-analysis version 2.2.040 software for dichotomous and continuous outcomes, respectively. RESULTS: Seven randomized controlled trials included 294 tracheal intubations by videolaryngoscopes and 253 tracheal intubations by Macintosh laryngoscopy. Videolaryngoscopes showed higher success rate (RR 1.116, 95% CI 1.021-1.220, P < 0.0155, I2 : 51%) and shorter intubation time (MD -11.9 sec, 95% CI-18.9(-) -5.0 sec, P < 0.0008, I2 84%) compared with the Macintosh laryngoscope. CONCLUSIONS: Our meta-analysis showed that the videolaryngoscope has an advantage over Macintosh laryngoscope in nasotracheal intubations.