Protocolized oxytocin infusion for elective cesarean delivery: a retrospective before-and-after study.

PURPOSE: To elucidate the clinical impact of the novel oxytocin protocol using a syringe pump with a stratified dose compared with the conventional practice of putting oxytocin into the bag. METHODS: This is a retrospective cohort study. We collected the data of the patients who underwent elective cesarean delivery under neuraxial anesthesia between June 2019 and May 2020. The patients were allocated to two groups according to oxytocin administration methods; the control group (the attending anesthesiologist put oxytocin 5-10 units in the infusion bag and adjusted manually after childbirth) and the protocol group (the oxytocin protocol gave oxytocin bolus 1 or 3 units depending on the PPH risk, followed by 5 or 10 unit h-1 via a syringe pump). We compared the total amount of oxytocin within 24 h postpartum, estimated blood loss, and adverse clinical events within 24 h postpartum between the two groups. RESULTS: During the study period, 262 parturients were included. Oxytocin doses of intraoperative and postoperative were significantly lower in the protocol group (9.7 vs. 11.7 units, intraoperative, 15.9 vs. 18 units, postoperative). The subgroup analyses showed that the impact was more remarkable in the low PPH risk than in the high PPH risk. The multivariate linear regression analyses also confirmed the difference. The groups had no significant difference in blood loss, requirement of additional uterotonics, and other adverse events. CONCLUSIONS: Our oxytocin infusion protocol significantly reduced oxytocin requirements in elective cesarean delivery under neuraxial anesthesia without increasing blood loss. However, we could not find other clinical benefits of the novel protocol.

Fixing the anesthesia research crisis in Japan.

To explore the current status of anesthesia research activity in Japan, we analyzed the number of abstracts presented at the Japanese Society of Anesthesiologists (JSA) annual meetings by several factors including gender, society branches, and subspecialty categories. The number of abstracts at JSA annual meetings has declined sharply since 2016 with no gender gap. A decrease in the neurological field predated the overall decline, but other subspecialty categories showed a similar decline. Although the Tokyo, Tokai-Hokuriku, and Kyushu branches were responsible for more than half of the reduction, the trend was similar among all branches. In a survey regarding academic activities of university hospital residents and faculty, Ph.D. aspirants' rate was only 20-30%. Residents had never presented an abstract at scientific conferences and never published any papers at nearly 40% and 30% of the university hospitals, respectively. Our survey suggests that junior anesthetists are losing interest in research. Senior faculty and mentors must redouble efforts to embed and encourage research in departments and by anesthetists in training. If a revival of anesthesia research in Japan does not occur then a service only specialty awaits.

Anesthesia practice for Cesarean delivery in Japan: a retrospective cohort study.

PURPOSE: General anesthesia for Cesarean delivery affects maternal and neonatal outcomes. We aimed to evaluate temporal trends in anesthesia management for Cesarean deliveries over 16 years and analyze interinstitutional variations in general anesthesia use in Japan. METHODS: In this retrospective cohort study, we obtained patient data from the nationwide health insurance claims database containing data for ten million individuals. We included patients who underwent Cesarean delivery between 1 January 2005 and 31 August 2021. The primary outcome was the use of general anesthesia. We evaluated institutional variations in general anesthesia use in medical facilities using two-level hierarchical logistic regression analyses with median odds ratios and intraclass correlation coefficients. RESULTS: The cohort included 86,793 patients who underwent 102,617 Cesarean deliveries at 2,496 institutions. General anesthesia was used in 3.7% (95% confidence interval [CI], 3.6 to 3.9) of all Cesarean deliveries. The temporal trend in the use of general anesthesia decreased gradually from 10.8% in 2005 to 2.9% in 2021 (P for trend < 0.001). The adjusted median odds ratio for medical facilities was 6.1 (95% CI, 5.9 to 6.7), and the intraclass correlation coefficient was 0.52 (95% CI, 0.51 to 0.55). CONCLUSION: Although the rate of general anesthesia use for Cesarean delivery in Japan decreased gradually from 2005 to 2021, general anesthesia was used in 3.7% of all Cesarean deliveries. The use of general anesthesia varied significantly across institutions, and 52% of the overall variations in general anesthesia practice can be explained by differences between facilities.

RéSUMé: OBJECTIF: L'anesthésie générale pour l'accouchement par césarienne affecte les issues maternelles et néonatales. Notre objectif était d'évaluer les tendances temporelles de la prise en charge anesthésique pour les accouchements par césarienne sur 16 ans et d'analyser les variations interinstitutionnelles dans l'utilisation de l'anesthésie générale au Japon. MéTHODE: Dans cette étude de cohorte rétrospective, nous avons obtenu des données sur les patient·es à partir de la base de données nationale des réclamations d'assurance maladie contenant des données pour dix millions de personnes. Nous avons inclus les personnes ayant bénéficié d'un accouchement par césarienne entre le 1er janvier 2005 et le 31 août 2021. Le critère d'évaluation principal était le taux d'utilisation de l'anesthésie générale. Nous avons évalué les variations institutionnelles dans l'utilisation de l'anesthésie générale dans les établissements médicaux à l'aide d'analyses de régression logistique hiérarchique à deux niveaux avec des rapports de cotes médians et des coefficients de corrélation intraclasse. RéSULTATS: La cohorte comprenait 86 793 patient·es ayant bénéficié de 102 617 accouchements par césarienne dans 2496 établissements. L'anesthésie générale a été utilisée dans 3,7 % (intervalle de confiance [IC] à 95 %, 3,6 à 3,9) de tous les accouchements par césarienne. La tendance temporelle de l'utilisation de l'anesthésie générale a diminué graduellement, passant de 10,8 % en 2005 à 2,9 % en 2021 (P pour la tendance < 0,001). Le rapport de cotes médian ajusté pour les établissements médicaux était de 6,1 (IC 95 %, 5,9 à 6,7), et le coefficient de corrélation intraclasse était de 0,52 (IC 95 %, 0,51 à 0,55).

Postpartum recovery of nulliparous women following scheduled cesarean delivery and spontaneous vaginal delivery: a prospective observational study.

BACKGROUND: Inpatient postpartum recovery trajectories following cesarean delivery and spontaneous vaginal delivery are underexplored. OBJECTIVE: This study primarily aimed to compare recovery following cesarean delivery and spontaneous vaginal delivery in the first postpartum week, and secondarily to evaluate psychometrically the Japanese version of the Obstetric Quality of Recovery-10 scoring tool. STUDY DESIGN: Following institutional review board approval, the EQ-5D-3L (EuroQoL 5-Dimension 3-Level) questionnaire and a Japanese version of the Obstetric Quality of Recovery-10 measure were used to evaluate inpatient postpartum recovery in uncomplicated nulliparous parturients delivering via scheduled cesarean delivery or spontaneous vaginal delivery. RESULTS: A total of 48 and 50 women who delivered via cesarean delivery and spontaneous vaginal delivery, respectively, were recruited. Women delivering via scheduled cesarean delivery experienced significantly worse quality of recovery on days 1 and 2 compared with those who had spontaneous vaginal delivery. Quality of recovery significantly improved daily, plateauing at days 4 and 3 for cesarean delivery and spontaneous vaginal delivery groups, respectively. Compared with cesarean delivery, spontaneous vaginal delivery was associated with prolonged time to analgesia requirement, decreased opioid consumption, reduced antiemetic requirement, and reduced times to liquid/solid intake, ambulation, and discharge. Obstetric Quality of Recovery-10-Japanese is a valid (correlates with the EQ-5D-3L including a global health visual analog scale, gestational age, blood loss, opioid consumption, time until first analgesic request, liquid/solid intake, ambulation, catheter removal, and discharge), reliable (Cronbach alpha=0.88; Spearman-Brown reliability estimate=0.94; and intraclass correlation coefficient=0.89), and clinically feasible (98% 24-hour response rate) measure. CONCLUSION: Inpatient postpartum recovery is significantly better in the first 2 postpartum days following spontaneous vaginal delivery compared with scheduled cesarean delivery. Inpatient recovery is largely achieved within 4 and 3 days following scheduled cesarean delivery and spontaneous vaginal delivery, respectively. Obstetric Quality of Recovery-10-Japanese is a valid, reliable, and feasible measure of inpatient postpartum recovery.

Comparison between neonatal outcomes of labor and delivery with labor neuraxial analgesia and without analgesia: A propensity score-matched study.

AIM: This single-center observational study aimed to investigate the association between labor neuraxial analgesia (LNA) and neonatal outcomes. METHODS: We conducted a retrospective cohort study at a tertiary perinatal center and included all vaginal deliveries performed between November 2015 and December 2021. Obstetric and neonatal outcomes were compared between deliveries with LNA (LNA group) and without analgesia (control group). Propensity score (PS) matching was used for statistical analysis. RESULTS: We included 2343 singleton deliveries performed in 1367 nulliparous and 976 multiparous women, in whom LNA was induced in 352 and 178 deliveries, respectively. After PS matching, the nulliparous LNA group had a significantly higher incidence of Apgar scores <7 at 1 (7.1% vs. 3.6%, p = 0.0139) and 5 min (2.3% vs. 0.7%, p = 0.0397) and meconium staining (29.8% vs. 23.2%, p = 0.0272) than the nulliparous control group. Other neonatal outcomes, including umbilical artery pH and neonatal intensive care unit admission rate, were comparable between the nulliparous LNA and control groups. No significant differences in neonatal outcomes were seen in multiparous women. Regarding fetal heart rate abnormalities, severe late deceleration (4.8% vs. 1.7%, p = 0.0036) and severe prolonged deceleration (17.0% vs. 11.9%, p = 0.0224) were more common in the nulliparous LNA group than in the nulliparous control group, and the multiparous LNA group exhibited more severe variable deceleration (21.3% vs. 14.3%, p = 0.0485) than the multiparous control group. CONCLUSION: Our findings suggest that LNA is associated with short-term adverse neonatal and obstetric outcomes in vaginal deliveries. LNA should be performed with precautionary measures and adequate medical resources.

Trend in neuraxial morphine use and postoperative analgesia after cesarean delivery in Japan from 2005 to 2020.

The increasing rate of cesarean deliveries warrants obstetric anesthesiologists to deliver high-quality post-cesarean delivery analgesia. The aim of this study was to evaluate the temporal trends in the use of neuraxial morphine for cesarean deliveries and to describe the current postoperative analgesia practices. A retrospective cohort study using nationwide health insurance claims databases was conducted from 2005 to 2020 in Japan. Pregnant women who had undergone cesarean deliveries were included. The annual rate of neuraxial morphine use was extracted and analyzed. Additionally, we explored the patient- and facility-level factors associated with neuraxial morphine use through a multilevel logistic regression analysis. The cohort included 65,208 cesarean delivery cases from 2275 institutions. The prevalence of neuraxial morphine use was 16.0% (95% confidence interval [CI], 15.8-16.3) in the overall cohort. Intrathecal morphine was used in 20.6% (95% CI, 20.2-21.0) of spinal anesthesia cases. The trend in neuraxial morphine use steadily increased from 2005 to 2020. The significant predictors of neuraxial morphine use included spinal anesthesia, recent surgery, large medical facilities, and academic hospitals. Variations in the utilization of postoperative analgesia were observed. Our study described the current trend of neuraxial morphine use and the variation in postoperative analgesia practice in Japan.

Current Epidemiology of the General Anesthesia Practice for Cesarean Delivery Using a Nationwide Claims Database in Japan: A Descriptive Study.

The current status of general anesthesia practice for cesarean delivery in Japan remains unknown. Therefore, using a nationwide claims database, we aimed to investigate general anesthesia use for cesarean delivery over a period of 15 years, and to analyze the general anesthesia practice in Japan. Patients who claimed the Japanese general anesthesia claim code (L008) for cesarean delivery between 1 January 2005, and 31 March 2020, were analyzed. Primary endpoint was the prevalence of general anesthesia use. We used two definitions of general anesthesia: L008 code only (insurance definition) and combination of the L008 code with muscle relaxant use (clinical definition). The general anesthesia claim cohort (L008) included 10,972 cesarean deliveries at 1111 institutions from 2005 to 2020. Muscle relaxants were used in 27.3% of L008 claims cases. The rate of general anesthesia use for cesarean delivery ranged from 3.9% in clinical definition to 14.4% in insurance definition of all cesarean deliveries. We observed a temporal trend of gradual decrease in general anesthesia use, regardless of its definition (p for trend < 0.001). We recommend the clinical definition of general anesthesia as the combination of L008 code and muscle relaxant use in a claims-based approach.

Programmed intermittent epidural bolus for labour analgesia: a randomized controlled trial comparing bolus delivery speeds of 125 mL·hr-1 versus 250 mL·hr-1.

PURPOSE: Programmed intermittent epidural bolus (PIEB) provides better analgesia for labour pain than continuous epidural infusion does. Nevertheless, commonly used PIEB regimens are associated with high sensory block. We hypothesized that a PIEB technique with slower bolus delivery speed would produce lower sensory levels. METHODS: We recruited term nulliparous women with singleton pregnancies during the first stage of labour. All participants had an American Society of Anesthesiologists Physical Status score of II-III, had epidural catheters placed at L3/4, and had epidural analgesia maintained with PIEB 10 mL every 40 min using 0.0625% bupivacaine with fentanyl 2 µg·mL-1. Women were randomized to receive PIEB delivered at 250 mL·hr-1 (G250) or 125 mL·hr-1 (G125). The study was completed six hours after the loading dose or at full cervical dilatation, whichever occurred first. The primary outcome was the presence of sensory block to ice ≥ T6 in at least one assessment during the study period (maximum six hours). RESULTS: We analyzed data from 90 women. The proportion of women presenting sensory block ≥ T6 at any time was not different between G125 and G250 groups (60.0% vs 64.4%; difference, -4.4%; 95% confidence interval [CI], -24.5 to 15.6; P = 0.66). The median [interquartile range] highest sensory block level was also not different between G125 and G250 groups (T6 [T7-T5] vs T5 [T7-T5], P = 0.39). Women in the G125 group had a lower incidence of hypotension than women in the G250 group did (11.1% vs 33.3%; difference, -22.2%; 95% CI, -38.8 to -5.67; P = 0.01). Quality of analgesia and patient satisfaction were not different between groups. CONCLUSION: The maintenance of epidural analgesia with a PIEB delivery speed of 125 mL·hr-1 did not produce lower sensory block levels when compared with 250 mL·hr-1. The slower injection speed regimen was associated with lower incidence of hypotension, but this secondary finding warrants confirmation in a future trial. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT03236298); registered 1 August 2017.

RéSUMé: OBJECTIF: L'administration programmée intermittente de bolus périduraux (PIEB, pour programmed intermittent epidural bolus) fournit une meilleure analgésie pour la douleur du travail que l'analgésie péridurale par perfusion continue. Néanmoins, les régimes de PIEB couramment utilisés sont associés à un bloc sensoriel élevé. Nous avons émis l'hypothèse qu'une technique de PIEB avec une vitesse d'administration plus lente du bolus produirait des niveaux sensoriels inférieurs. MéTHODE: Nous avons recruté des femmes nullipares à terme ayant des grossesses uniques au cours de la première étape du travail obstétrical. Toutes les participantes avaient un score de statut physique II-III de l'American Society of Anesthesiologists, des cathéters périduraux placés au niveau L3/4 et une analgésie péridurale maintenue avec des PIEB de 10 mL de bupivacaïne 0,0625 % et de 2 µg·mL-1 de fentanyl, administrés toutes les 40 minutes. Les femmes ont été randomisées à recevoir des PIEB administrés à une vitesse de 250 mL·h-1 (G250) ou 125 mL·h-1 (G125). L'étude se terminait six heures après la dose de charge ou lors de la dilatation cervicale complète, selon la première éventualité. Le critère d'évaluation principal était la présence d'un bloc sensoriel à la glace ≥ T6 lors d'au moins une évaluation au cours de la période à l'étude (pour un maximum de six heures). RéSULTATS: Nous avons analysé les données de 90 femmes. La proportion de femmes présentant un bloc sensoriel ≥ T6 à tout moment n'était pas différente entre les groupes G125 et G250 (60,0 % vs 64,4 %; différence, -4,4 %; intervalle de confiance [IC] à 95 %, -24,5 à 15,6; P = 0,66). Le niveau médian [écart interquartile] le plus élevé de bloc sensoriel n'était pas non plus différent entre les groupes G125 et G250 (T6 [T7-T5] vs T5 [T7-T5], P = 0,39). Les femmes du groupe G125 avaient une incidence d'hypotension plus faible que les femmes du groupe G250 (11,1 % vs 33,3 %; différence, -22,2 %; IC 95 %, -38,8 à -5,67; P = 0,01). La qualité de l'analgésie et la satisfaction des patientes n'étaient pas différentes d'un groupe à l'autre. CONCLUSION: Le maintien de l'analgésie péridurale avec une vitesse d'administration des PIEB de 125 mL·h-1 n'a pas entraîné de taux de blocs sensoriels inférieurs par rapport à une vitesse de 250 mL·h-1. Le régime de vitesse d'injection plus lente a été associé à une incidence plus faible d'hypotension, mais cette constatation secondaire mérite d'être confirmée dans une étude future. ENREGISTREMENT DE L'éTUDE: www.ClinicalTrials.gov (NCT03236298); enregistrée le 1er août 2017.

Developing a business case for a regional anesthesia block room: up with efficiency, down with costs.

BACKGROUND: Regional anesthesia techniques offer many benefits for total joint arthroplasty (TJA) patients. However, they require personnel and equipment resources, as well as valuable operating room (OR) time. A block room offers a dedicated environment to perform regional anesthesia procedures while potentially offsetting costs. METHODS: The goal of this prospective quality improvement study was to develop a business case for implementation of a regional anesthesia block room and to demonstrate the cost-effectiveness of this program in decreasing OR time for TJA. All elective TJA patients presenting between January 2019 and March 2020 were included in our analysis. RESULTS: Our detailed business plan was approved by the hospital leadership. 561 patients in the preintervention group and 432 in the postintervention group were included for data analysis. Mean total OR time per surgical case decreased from 166 to 143 min for a difference of 23 min (95% CI 17 to 29). Similarly, anesthesia controlled OR time decreased from 46 min to 26 min for a difference of 20 min (95% CI 17 to 22). The block room resulted in an additional primary TJA case per daily OR list. The percentage of TJA patients receiving a peripheral nerve block increased from 63.1% to 87.0% (p<0.001). No safety events or block room associated OR delays were observed. CONCLUSION: Implementing a regional anesthesia block room required a comprehensive business plan for securing the necessary resources to support the program. The regional anesthesia block room is a cost-effective method to improve patient care and OR efficiency.

Reducing Acute Hospitalization Length of Stay After Total Knee Arthroplasty: A Quality Improvement Study.

BACKGROUND: The introduction of bundled funding for total knee arthroplasty (TKA) has motivated hospitals to improve quality of care while minimizing costs. The aim of our quality improvement project is to reduce the acute hospitalization length of stay to less than 2 days and decrease the percentage of TKA patients discharged to inpatient rehabilitation using an enhanced recovery after surgery bundle. METHODS: This study used a before-and-after design. The pre-intervention period was January to December 2017 and the post-intervention period was January 2018 to August 2019. A root cause analysis was performed by a multidisciplinary team to identify barriers for rapid recovery and discharge. Four new interventions were chosen as part of an improvement bundle based on existing local practices, literature review, and feasibility analysis: (1) perioperative peripheral nerve block; (2) prophylactic antiemetic medication; (3) avoidance of routine preoperative urinary catheterization; and (4) preoperative patient education. RESULTS: The pre-intervention and post-intervention groups included 232 and 383 patients, respectively. Mean length of stay decreased from 2.82 to 2.13 days (P < .001). The need for inpatient rehabilitation decreased from 20.2% to 10.7% (P = .002). Mean 24-hour oral morphine consumption decreased from 60 to 38 mg (P < .001). The percentage of patients experiencing moderate-to-severe pain and postoperative nausea and vomiting within the first 24 hours decreased by 25% and 15%, respectively (P < .001). Thirty-day emergency department visits following discharge decreased from 12.9% to 7.3% (P = .030). CONCLUSION: Significant improvements in the recovery of patients after TKA were achieved by performing a root cause analysis and implementing a multidisciplinary, patient-centered enhanced recovery after surgery bundle. LEVEL OF EVIDENCE: Level III.

Management of pregnancy and delivery in women with Kawasaki disease and residual coronary artery lesion with detailed analysis of labor analgesia: combined experience of 13 cases in two institutions.

INTRODUCTION: Approximately half of Kawasaki disease patients are expected to have transitioned to adulthood, and an increasing number of patients with cardiovascular sequelae have gotten pregnant. Management of women with Kawasaki disease who have residual coronary artery disease is poorly established. Thus, we conducted detailed analysis of these cases. METHODS: We reviewed 19 pregnancies in 13 such women in two tertiary perinatal facilities, Saitama Medical Center and National Cardiovascular Center. The medical records were reviewed in all women with Kawasaki disease and coronary artery lesion between 1998 and 2015, with regard to age of diagnosis, types of coronary artery lesion, location, previous treatment, pregnancy course and medical management for coronary lesion, cardiac function, and planned mode of delivery. RESULTS: Fourteen parturients attempted vaginal delivery, and all but one received neuraxial analgesia, providing stable hemodynamics. Four elective and two emergency cesarean deliveries were performed due to obstetric indications, while one woman required cesarean delivery at preterm due to maternal cardiac indication. Among 14 attempted vaginal deliveries, instrumental vaginal delivery was performed in 50%. Cardiac events were noted in four women, all in post-partum period, such as non-sustained ventricular tachycardia or chest discomfort without ECG changes. Antithrombotic medication was exclusively low dose aspirin in 11 of 19 pregnancies (58%), and none received anticoagulation during pregnancy or delivery. CONCLUSION: Our case series support the practice of preferred vaginal delivery, with neuraxial labor analgesia in indicated patients, while highlighting the need for vigilance in the post-partum period.

Postoperative renal function in parturients with severe preeclampsia who underwent cesarean delivery: a retrospective observational study.

Although postoperative renal dysfunction is relatively rare after cesarean delivery, preeclampsia is considered as the high-risk population. On the other hand, hydroxyethyl starch (HES) administration for preventing maternal hypotension induced by spinal anesthesia for cesarean delivery is a common practice. However, the effect of HES administration during cesarean delivery on postoperative kidney function in parturients with severe preeclampsia is not well investigated. We retrospectively reviewed both medical and anesthesia records of patients with severe preeclampsia who underwent cesarean delivery from January 2011 to December 2013. Preoperative blood examinations were compared with postoperative values. All parturients received 6% HES 70/0.5 for preventing anesthesia-induced hypotension or for volume resuscitation during cesarean delivery. A total of 87 severe preeclampsia parturients were underwent cesarean section during the period. The amounts of HES administration were 859 ± 206 mL. There was significant reduction in serum creatinine, from 0.70 ± 0.29 mg/dL preoperatively to 0.62 ± 0.17 mg/dL in 3-7 days after the cesarean. Only one patient had postoperatively elevated serum creatinine up to clinically significant level (from 0.64 mg/dL to 1.35 mg/kg).

Outcomes of labor epidural analgesia among women aged over 40: A single-institution retrospective study.

AIM: The purpose of this study was to investigate the effects of labor epidural analgesia (LEA) on maternal and neonatal outcomes among parturients aged 40 years or older. METHODS: We retrospectively reviewed medical records of all laboring, singleton and cephalic deliveries at ≥36 weeks' gestation at the Saitama Medical Center from April 2003 to September 2012. Women aged ≥40 years who received LEA (≥40 with LEA group) were compared with women aged ≥40 years who delivered without LEA (≥40 without LEA group) and women <40 years who received LEA (<40 with LEA group). Extracted outcomes included mode of delivery, oxytocin augmentation, duration of labor, amount of estimated blood loss, umbilical artery pH, Apgar scores, and neonatal intensive care unit admission. RESULTS: This study included 4441 women. There were 74 women in the ≥40 with LEA group, 369 in the ≥40 without LEA group, and 601 in the <40 with LEA group. The maternal outcomes of emergency cesarean delivery rate (9.5%, 12.5%, 9.0%), instrumental delivery rate (33.8%, 10.3%, 28.3%), duration of labor (521 min, 321 min, 565 min), and estimated blood loss (524 g, 351 g, 412 g) were reported for the ≥40 with LEA, ≥40 without LEA, and <40 with LEA groups, respectively. Neonatal outcomes were not different between these groups. LEA use was not associated with emergency cesarean delivery in the multivariable analysis. CONCLUSION: Our study showed that parturients aged ≥40 with LEA can expect similar LEA-associated labor outcomes to younger parturients with LEA.

GlmS and NagB regulate amino sugar metabolism in opposing directions and affect Streptococcus mutans virulence.

Streptococcus mutans is a cariogenic pathogen that produces an extracellular polysaccharide (glucan) from dietary sugars, which allows it to establish a reproductive niche and secrete acids that degrade tooth enamel. While two enzymes (GlmS and NagB) are known to be key factors affecting the entrance of amino sugars into glycolysis and cell wall synthesis in several other bacteria, their roles in S. mutans remain unclear. Therefore, we investigated the roles of GlmS and NagB in S. mutans sugar metabolism and determined whether they have an effect on virulence. NagB expression increased in the presence of GlcNAc while GlmS expression decreased, suggesting that the regulation of these enzymes, which functionally oppose one another, is dependent on the concentration of environmental GlcNAc. A glmS-inactivated mutant could not grow in the absence of GlcNAc, while nagB-inactivated mutant growth was decreased in the presence of GlcNAc. Also, nagB inactivation was found to decrease the expression of virulence factors, including cell-surface protein antigen and glucosyltransferase, and to decrease biofilm formation and saliva-induced S. mutans aggregation, while glmS inactivation had the opposite effects on virulence factor expression and bacterial aggregation. Our results suggest that GlmS and NagB function in sugar metabolism in opposing directions, increasing and decreasing S. mutans virulence, respectively.