Initial loading of dexmedetomidine and continuous propofol sedation for prevention of delayed recovery: A randomized controlled trial.

BACKGROUND: Sedation with continuous dexmedetomidine and bolus midazolam administration provides a lower incidence of unacceptable patient movement during procedures but requires a longer recovery time. The authors aimed to compare recovery time and unacceptable patient movement during sedation with initial loading of dexmedetomidine followed by continuous propofol infusion with those during sedation with continuous dexmedetomidine and bolus midazolam administration. METHODS: In this prospective randomized controlled trial, 54 patients undergoing dental surgery and requiring intravenous sedation were assigned to either the dexmedetomidine and propofol group (n = 27, dexmedetomidine administered at 6 µg/kg/h for 5 minutes, followed by continuous propofol infusion using a target-controlled infusion) or the dexmedetomidine and midazolam group (n = 27, dexmedetomidine administered at 0.2-0.7 µg/kg/h continuously after the same initial loading dose with bolus midazolam). A bispectral index of 70 through 80 was maintained during the procedure. Patient movement that interfered with the procedure and time from the end of sedation to achieving a negative Romberg sign were assessed. RESULTS: Times from the end of sedation to achieving a negative Romberg sign in the dexmedetomidine and propofol group (median, 14 minutes [interquartile range, 12-15 minutes]) were significantly shorter (P < .001) than in the dexmedetomidine and midazolam group (median, 22 minutes [interquartile range, 17.5-30.5 minutes]). The incidence of unacceptable patient movement was comparable between groups (n = 3 in the dexmedetomidine and propofol group, n = 4 in the dexmedetomidine and midazolam group; P = .999). CONCLUSIONS: Sedation with a single loading dose of dexmedetomidine followed by continuous propofol infusion can prevent delayed recovery without increasing unacceptable patient movement. PRACTICAL IMPLICATIONS: The combination of dexmedetomidine and propofol may provide high-quality sedation for ambulatory dental practice. This clinical trial was registered in the University Hospital Medical Information Network Clinical Trials Registry. The registration number is UMIN000039668.

Evaluation of the effects of manual acupuncture and electroacupuncture at LI4 and LI11 on perception thresholds: a prospective crossover trial.

OBJECTIVE: The objective of the study was to investigate and compare the effects of manual acupuncture (MA) and electroacupuncture (EA) on current perception thresholds (CPTs) using quantitative methods. METHODS: Twenty-nine healthy volunteers participated in this prospective crossover trial, in which three acupuncture methods were compared: control, MA, and EA. Acupuncture needles were inserted to a depth of 15 mm at LI4 and LI11 on the left side and retained for 30 min with or without electrical stimulation at a frequency of 2 Hz (EA and MA, respectively). The needles were removed and participants rested for 30 min. CPT in the left mental region was measured at 2000, 250, and 5 Hz, corresponding to the activation of Aß, Aδ, and C-fibers, respectively, at four time points: baseline, T0; 15 min after needle application, T1; immediately after needle removal, T2; and 30 min after needle removal, T3. In the control session, only a sensory test was performed (without acupuncture). RESULTS: Significant effects of time course on CPT were observed (p < 0.001). CPT values increased significantly at T1, T2, and T3, compared with those at T0, at all stimulation frequencies during MA and EA. Changes in CPT values with EA were not significantly greater than those with MA. CONCLUSIONS: Both MA and EA increased the sensory thresholds of Aß, Aδ, and C-fibers in the mental region for ⩾30 min after needle removal. Additional of electrical stimulation may not confer additional benefits over needling alone. TRIAL REGISTRATION NUMBER: UMIN000017983 (University Hospital Medical Information Network Clinical Trials Registry).

Clinical Use of Preformed Microcuff® Pediatric Endotracheal Tubes in Japan.

Preformed cuffed oral endotracheal tubes are widely used to intubate children undergoing oral surgery. To evaluate the efficacy and safety of oral Ring-Adair-Elwyn (RAE) Microcuff® pediatric endotracheal tubes, we retrospectively investigated the endotracheal tube exchange rate and associated complications in Japanese children younger than 2 years of age undergoing cheiloplasty or palatoplasty. The exchange rate was 3.5%, and although unplanned extubations occurred in 2 patients, no severe complications were observed. Our results suggest that oral RAE Microcuff® tubes are effective and safe for intubating Japanese children younger than 2 years of age, with a low tube exchange rate and minor complications.

Frequency of the requirement of inappropriate uncuffed tracheal tube size for pediatric patients: a retrospective observational analysis.

BACKGROUND: The insertion of inappropriately sized uncuffed endotracheal tubes (ETTs) with a tight seal or presence of air leakage may be necessary in children. This study aimed to analyze the frequency of the requirement of inappropriately sized uncuffed ETT insertion, air leakage after the ETT was replaced with one of a larger size, and factors associated with air leakage after ETT replacement. METHODS: Patients under 2 years of age who underwent oral surgery under general anesthesia with uncuffed ETTs between December 2013 and May 2015 were enrolled. The ETT size was selected at the discretion of the attending anesthesiologists. A leak test was performed after intubation. The ETT was replaced when considered necessary. Data regarding the leak pressure (PLeak) and inspiratory and expiratory tidal volumes were extracted from anesthesia records. We considered a PLeak of 10 < PLeak ≤ 30 cmH2O to be appropriate. The frequencies of the requirement of inappropriately sized ETTs, absence of leakage after ETT replacement, ETT size difference, and leak rate were calculated. A logistic regression was performed, with PLeak, leak rate, and size difference included as explanatory variables and presence of leakage after replacement as the outcome variable. RESULTS: Out of the 156 patients enrolled, 109 underwent ETT replacement, with the requirement of inappropriately sized ETTs being observed in 25 patients (23%). ETT replacement was performed in patients with PLeak ≤ 10 cmH2O; leakage was absent after replacement (PLeak < 30 cmH2O) in 52% of patients (25/48). In the multivariate logistic model, the leak rate before ETT replacement was significantly associated with the presence of leakage after replacement (p = 0.021). CONCLUSIONS: Inappropriately sized ETTs were inserted in approximately 23% of the patients. The leak rate may be useful to guide ETT replacement.

Age-based prediction of uncuffed tracheal tube size in children to prevent inappropriately large tube selection: a retrospective analysis.

BACKGROUND: This study aims to validate our previously reported prediction technique for uncuffed tracheal tube (TT) sizes in children younger than 2 years of age based on a calculated outer diameter (ODCal, mm) in each patient according to the regression equation ODCal = 0.00223 × age (day) + 4.88 and to investigate a better method to select initial TT sizes to decrease re-intubation frequency, especially since large tubes can damage the trachea. METHODS: We included patients younger than 2 years of age who underwent oral surgery under general anesthesia with tracheal intubation between July 2011 and December 2016 at the Osaka University Dental Hospital. The OD of the actual TT and the age in days were extracted from anesthesia records. Agreement rates, estimated numbers of required tubes, and size reduction frequencies were compared to obtain recommended OD (ODRec) values in 2 selection groups: "average selection" in the range "nearest to the ODCal value (ODCal - 0.35 < ODRec ≤ ODCal + 0.35)" and "safe selection" in the range "nearest to the value below ODCal (ODCal - 0.7 < ODRec ≤ ODCal)". RESULTS: The agreement rates for an ODRec in the average selection and safe selection groups were 60.8 and 55.1%, respectively (P = 0.001). The estimated number of required tubes per patient were 1.40 ± 0.51 and 1.47 ± 0.55 (P < 0.001), respectively. The estimated frequencies of size reductions were 13.3 and 4.0% (P < 0.001), respectively. CONCLUSIONS: Because the size reduction frequency is lower despite a slightly higher number of required TTs, selecting an ODRec based on "safe selection" parameters is desirable to avoid complications due to intubation with larger TTs.

Dexmedetomidine and Midazolam Sedation Reduces Unexpected Patient Movement During Dental Surgery Compared With Propofol and Midazolam Sedation.

PURPOSE: Owing to its unpredictability, unexpected patient movement is one of the most important problems during surgery while under monitored anesthesia care with sedation. The purpose of this study was to compare unexpected patient movement during dental surgery while under dexmedetomidine and propofol sedation. MATERIALS AND METHODS: The authors designed and implemented a prospective randomized controlled trial. Patients undergoing dental surgery requiring intravenous sedation were randomly assigned to dexmedetomidine and midazolam (dexmedetomidine group) or propofol and midazolam (propofol group) sedation. In each group, midazolam 0.02 mg/kg was administered in conjunction with continuous administration of dexmedetomidine or propofol to maintain a bispectral index value of 70 to 80. Unexpected patient movement interfering with the procedure was defined as acceptable, defined as no body movement or only 1 controllable movement, or unacceptable, defined as at least 2 controllable movements or any uncontrollable movement. The primary outcome was unexpected patient movement, and the secondary outcome was defined as snoring and cough reflex. Other variables included demographic and procedural characteristics. Continuous or ordinal variables were analyzed using the Student t test or Mann-Whitney test. Dichotomous or categorical variables were analyzed using the χ2 test or Fisher exact test. A P value less than.05 was considered statistically significant. RESULTS: Eighty-eight patients were enrolled in the study (dexmedetomidine group, n = 44; propofol group, n = 44). There were no relevant differences between groups for demographics and baseline variables. Intraoperative unacceptable patient movement occurred more commonly in the propofol group (n = 13; 30%) than in the dexmedetomidine group (n = 4; 9%; P = .015). Intraoperative snoring occurred more commonly in the dexmedetomidine than in the propofol group (P = .045). Incidence and number of cough reflexes were comparable between groups. CONCLUSION: Dexmedetomidine and midazolam sedation decreases unexpected patient movement during dental surgery compared with propofol and midazolam sedation.

Airway management for glossopexy in infants with micrognathia and obstructive breathing.

STUDY OBJECTIVES: To identify airway management and tracheal intubation techniques for glossopexy in infants with preexisting airway obstruction under general anesthesia. DESIGN: Retrospective, observational study. SETTINGS: Operating room of a university hospital between January 2003 and March 2015. All operations were performed by oral and maxillofacial surgeons. PATIENTS: Thirteen patients who received general anesthesia for glossopexy and reversal after 7 months. MEASUREMENTS: The medical records of these infants were retrospectively examined to evaluate the following: age, sex, height and weight at surgery, preoperative airway status, tracheal intubation route (oral or nasal), method for inducing general anesthesia, method for establishing the airway during mask ventilation, apparatus used for tracheal intubation, Cormack-Lehane classification when using a Macintosh laryngoscope and video laryngoscope, and the need for airway placement after extubation. RESULTS: Prone positioning and/or an airway of some kind before surgery were required in 38.5% of infants needing glossopexy. Difficult mask ventilation was common, occurring in 50% of the patients, and the incidence of airway placement during mask ventilation was significantly higher in infants with preoperative complete or incomplete obstruction (100%) than in infants with snoring (25%). Of these high-risk infants, 25% could not be intubated with a direct laryngoscope or Glidescope Cobalt and required fiberoptic intubation. CONCLUSION: There are severe cases of infants with difficult mask ventilation and difficult tracheal intubation in which a fiberscope is required because video laryngoscopy fails to improve the view of the larynx.

Trigeminal nervous system sensitization by infraorbital nerve injury enhances responses in a migraine model.

Background Although the peripheral and central sensitizations of trigeminal nervous system may be one of the important factors of migraine, the precise mechanism is not fully understood. In this study, we examined the influence of the sensitization of the second division of the trigeminal nerve (V2) by chronic constriction injury (CCI) of the infraorbital nerve (ION) on migraine headache, using the capsaicin-induced migraine model. Methods Male Sprague-Dawley rats were assigned to four groups: (a) sham surgery and topical-dural vehicle application (Sham + Vehicle) group, (b) CCI-ION and topical-dural vehicle application (CCI-ION + Vehicle) group, (c) sham surgery and topical-dural capsaicin application (Sham + Capsaicin) group, (d) CCI-ION and topical-dural capsaicin application (CCI-ION + Capsaicin) group. Behavioral testing and immunohistochemical staining were performed. Results In the behavioral test, the Sham + Capsaicin group showed significantly longer duration of immobilization and shorter duration of exploration compared with the Sham + Vehicle group, which is similar to clinical features of migraine patients. Moreover, CCI-ION enhanced these effects in the CCI-ION + Capsaicin group. Immunohistochemical staining for phospho-extracellular signal-related kinase (pERK) in the trigeminal ganglion (TG) containing first and second divisions of the trigeminal nerve and the trigeminocervical complex (TCC) revealed that pERK expression was significantly increased in the CCI-ION + Capsaicin group compared with the other groups. However, comparing between effects of the peripheral and central sensitizations (in the TG and TCC), from our results, peripheral sensitization would play a much less or not significant role. Conclusions These data demonstrate that the sensitization of V2 could influence the activation and the sensitization of the first division of the trigeminal nerve in the TCC, subsequently exacerbating pain sensation and pain-related behaviors. We have shown for the first time that the existence of the central sensitization of V2 can be an exacerbating factor for migraine related nociceptive thresholds/activation.

Effectiveness of dexmedetomidine for emergence agitation in infants undergoing palatoplasty: a randomized controlled trial / Eficácia de dexmedetomidina para o surgimento de agitação em lactentes submetidos à palatoplastia: estudo clínico randomizado

OBJECTIVES: In infants, there is a high incidence of emergence agitation (EA) after sevoflurane (Sev) anesthesia. This study aimed to test the hypothesis that dexmedetomidine (Dex) administration would reduce the incidence and severity of EA after Sev-based anesthesia in infants undergoing palatoplasty. METHODS: A prospective randomized clinical trial was conducted with 70 patients undergoing palatoplasty, aged 10-14 months. Infants were randomly allocated into two groups: Dex (n = 35) and saline (n = 35). In the Dex group, Dex (6 µg/kg/h) was administered approximately 10 min before the end of the surgery for 10 min, followed by 0.4 µg/kg/h until 5 min after extubation. In the saline group, an equivalent amount of saline was administered in a similar manner. After the surgery, patients were transferred to the postanesthetic care unit (PACU). The infant's behavior and pain were assessed with scoring system for EA (5-point rating scale) and pain scale (PS; 10-point rating scale), respectively. EA and PS were estimated at six time points (after extubation, leaving the operating room, 0, 30, 60, and 120 min after arrival in PACU). RESULTS: EA and PS scores were significantly lower in the Dex group than in the saline group from extubation to 120 min after arrival in PACU. CONCLUSIONS: Dex administration has the advantage of a reduced EA and PS without any adverse effects. Dex provided satisfactory recovery in infants undergoing palatoplasty.

OBJETIVOS: Em crianças, é elevada a incidência de surgimento de agitação (SA) em seguida à anestesia com sevoflurano (Sev). Este estudo teve como objetivo testar a hipótese de que a administração de dexmedetomidina (Dex) reduziria a incidência e a gravidade do SA após anestesia com Sev em lactentes submetidos à palatoplastia. MÉTODOS: Estudo clínico prospectivo randomizado, feito com 70 pacientes submetidos a uma palatoplastia, com 10-14 meses. As crianças foram divididas randomicamente em dois grupos: Dex (n = 35) e solução salina (n = 35). No grupo de Dex, Dex (6 µg/kg/h) foi administrada cerca de 10 minutos antes do fim da cirurgia durante 10 minutos, seguida de 0,4 µg/kg/h até 5 minutos após a extubação. No grupo de solução salina, uma quantidade equivalente de salina foi administrada com o mesmo esquema de dosagem. Após a cirurgia, os pacientes foram transferidos para a unidade de cuidados pós-anestésicos (UCPA). O comportamento e a dor dos bebês foram avaliados com um sistema de pontuação para SA (escala de classificação de 5 pontos) e com uma escala de dor (ED; escala de classificação de 10 pontos), respectivamente. SA e ED foram estimados em seis pontos cronológicos (após a extubação, ao deixar a sala de cirurgia e 0, 30, 60 e 120 minutos após a chegada à UCPA). RESULTADOS: Os escores SA e ED foram significativamente menores no grupo Dex versus grupo salina, desde a extubação até 120 minutos após a chegada à UCPA. CONCLUSÕES: A administração de Dex tem a vantagem de uma redução no SA e na ED, sem quaisquer efeitos adversos. Dex proporcionou uma recuperação satisfatória em lactentes submetidos à palatoplastia.

Effectiveness of dexmedetomidine for emergence agitation in infants undergoing palatoplasty: a randomized controlled trial.

OBJECTIVES: In infants, there is a high incidence of emergence agitation (EA) after sevoflurane (Sev) anesthesia. This study aimed to test the hypothesis that dexmedetomidine (Dex) administration would reduce the incidence and severity of EA after Sev-based anesthesia in infants undergoing palatoplasty. METHODS: A prospective randomized clinical trial was conducted with 70 patients undergoing palatoplasty, aged 10-14 months. Infants were randomly allocated into two groups: Dex (n=35) and saline (n=35). In the Dex group, Dex (6 µg/kg/h) was administered approximately 10 min before the end of the surgery for 10 min, followed by 0.4 µg/kg/h until 5 min after extubation. In the saline group, an equivalent amount of saline was administered in a similar manner. After the surgery, patients were transferred to the postanesthetic care unit (PACU). The infant's behavior and pain were assessed with scoring system for EA (5-point rating scale) and pain scale (PS; 10-point rating scale), respectively. EA and PS were estimated at six time points (after extubation, leaving the operating room, 0, 30, 60, and 120 min after arrival in PACU). RESULTS: EA and PS scores were significantly lower in the Dex group than in the saline group from extubation to 120 min after arrival in PACU. CONCLUSIONS: Dex administration has the advantage of a reduced EA and PS without any adverse effects. Dex provided satisfactory recovery in infants undergoing palatoplasty.

[Effectiveness of dexmedetomidine for emergence agitation in infants undergoing palatoplasty: a randomized controlled trial]. / Eficácia de dexmedetomidina para o surgimento de agitação em lactentes submetidos à palatoplastia: estudo clínico randomizado.

OBJECTIVES: In infants, there is a high incidence of emergence agitation (EA) after sevoflurane (Sev) anesthesia. This study aimed to test the hypothesis that dexmedetomidine (Dex) administration would reduce the incidence and severity of EA after Sev-based anesthesia in infants undergoing palatoplasty. METHODS: A prospective randomized clinical trial was conducted with 70 patients undergoing palatoplasty, aged 10-14 months. Infants were randomly allocated into two groups: Dex (n=35) and saline (n=35). In the Dex group, Dex (6µg/kg/h) was administered approximately 10min before the end of the surgery for 10min, followed by 0.4µg/kg/h until 5min after extubation. In the saline group, an equivalent amount of saline was administered in a similar manner. After the surgery, patients were transferred to the postanesthetic care unit (PACU). The infant's behavior and pain were assessed with scoring system for EA (5-point rating scale) and pain scale (PS; 10-point rating scale), respectively. EA and PS were estimated at six time points (after extubation, leaving the operating room, 0, 30, 60, and 120min after arrival in PACU). RESULTS: EA and PS scores were significantly lower in the Dex group than in the saline group from extubation to 120min after arrival in PACU. CONCLUSIONS: Dex administration has the advantage of a reduced EA and PS without any adverse effects. Dex provided satisfactory recovery in infants undergoing palatoplasty.

Haemostatic management for oral surgery in patients supported with left ventricular assist device--a preliminary retrospective study.

We investigated haemostatic management, frequency of postoperative bleeding, and prognosis of patients who had left ventricular assist devices, and who were having oral surgical procedures between April 2002 and March 2014, to identify risk factors for bleeding and find out which were the best methods of haemostasis. Medical records were examined retrospectively and we recorded details of the patients, and frequency of bleeding together with factors associated with it. Twenty-nine patients had 39 oral operations, and there were 17 bleeds (44%). The first procedure for each patient was used for statistical calculations. Duration of bleeding tended to be longer for patients with implantable devices (median (interquartile range, IQR) 12.0 (3-18) days) than for those with extracorporeal devices (median (IQR) 3.0 (1-4) days; p=0.079). There was a significantly greater difference in prothrombin time-international normalised ratio (PT-INR) before and after operation in patients who bled, whose median (range) was 0.85 (0.2-1.81), than in those who did not (median (IQR) 0.16 (-0.09-0.31) (p=0.015). There were moderate correlations with postoperative bleeding were seen for the difference between preoperative and postoperative PT-INR (r=0.479, p=0.012) and PT-INR value when bleeding (r=0.407, p=0.035). In conclusion, postoperative bleeding occurred after oral operations in 17/29 patients with left ventricular assist devices by a median (IQR) of 0.85 (0.2-1.81) of the preoperative value.

Neural mechanism underlying hyperalgesic response to orofacial pain in Parkinson's disease model rats.

To investigate the neural mechanism of pain originating from the orofacial region in PD patients, we used PD model rats produced by unilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle. We investigated effects of nigrostriatal lesions on the behavioral response (face rubbing) to formalin injection into the upper lip. We also examined expression of c-Fos and phosphorylated extracellular signal-regulated kinase (pERK) in the trigeminal spinal subnucleus caudalis (Vc) and expression of c-Fos in the periaqueductal gray matter (PAG). Face rubbings following formalin injection showed a biphasic profile, with the first phase for the first 5 min and the second phase from 10 to 90 min. Rats with 6-OHDA lesions showed increased face rubbings in the second phase when formalin was injected ipsilaterally to the lesion, and c-Fos expression in the Vc increased. When formalin was injected contralaterally, face rubbings were reduced in the first phase, however, expression levels of c-Fos and pERK in the Vc were unchanged. No significant difference was found in c-Fos expression in the PAG between 6-OHDA- and saline-injected rats. These results suggest that unilateral dopamine depletion in the nigrostriatal pathway may be involved in hypersensitivity to noxious stimulation delivered to the orofacial region.

A prospective, randomized controlled trial of conscious sedation using propofol combined with inhaled nitrous oxide for dental treatment.

PURPOSE: Adverse reactions during propofol sedation include a decrease in arterial blood pressure, propofol-induced pain on injection, and airway complications. The purpose of this study was to investigate whether combined use of intravenous propofol and inhaled nitrous oxide could decrease the hypotensive and other adverse effects of propofol. PATIENTS AND METHODS: We designed and implemented a prospective, randomized controlled trial. Patients undergoing dental procedures requiring intravenous sedation were randomly allocated to 2 groups: group P comprised those receiving sedation with propofol alone, and group N+P comprised those receiving sedation with 40% nitrous oxide inhalation and propofol. During the dental procedures, the sedation level was maintained at an Observer's Assessment of Alertness/Sedation scale score of 4 by adjusting propofol's target plasma concentration. Nitrous oxide inhalation was the predictor variable, whereas the hemodynamic changes, amount and concentration of propofol, and adverse events were the outcome variables. RESULTS: Eighty-eight patients were successfully analyzed without any complications. The total amount of propofol was significantly less in group N+P (249.8 ± 121.7 mg) than in group P (310.3 ± 122.4 mg) (P = .022), and the mean concentration of propofol was significantly less in group N+P (1.81 ± 0.34 µg/mL) than in group P (2.05 ± 0.44 µg/mL) (P = .006). The mean blood pressure reduction in group N+P (11.0 ± 8.0 mm Hg) was significantly smaller than that in group P (15.8 ± 10.2 mm Hg) (P = .034). Pain associated with the propofol injection and memory of the procedure were less in group N+P (P = .011 and P = .048, respectively). Nitrous oxide did not affect respiratory conditions or recovery characteristics. CONCLUSIONS: The results of this study suggest that nitrous oxide inhalation combined with propofol sedation attenuates the hypotensive effect and pain associated with propofol injections, along with potentiating the amnesic effect.

Arteriosclerosis can predict hypotension during anesthesia induction in patients 40 years and older.

STUDY OBJECTIVES: To identify the factors that predict blood pressure (BP) changes during induction of general anesthesia, and the relationship between the level of arteriosclerosis and BP changes during anesthesia induction. DESIGN: Prospective, case-control observational study. SETTINGS: Operating room of a university hospital. PATIENTS: Seventy-two patients who received general anesthesia for oral and maxillofacial surgery. MEASUREMENTS: Brachial-ankle pulse wave velocity (baPWV) and central BP were measured. The primary variable was the parameters affecting BP changes during the induction of general anesthesia. For additional analyses, the parameters were compared between high and low PWV groups (1606 cm/s was the cutoff value of baPWV). To measure the relationships between the parameters and BP changes, bivariate and multiple linear regression analyses were performed. RESULTS: Seventy-two patients (including 41 men) with a mean age of 61.7 years and a median baPWV value of 1606 cm/s were evaluated. Significantly higher values for age, central BP, preoperative systolic BP (SBP), amount of decrease in SBP and diastolic BP, and number of patients with diabetes mellitus (DM) and hypertension were observed in the high PWV group. Multiple linear regression analysis demonstrated that age, baPWV, and DM were factors independently associated with the amount of decrease in SBP. CONCLUSION: In patients 40 years and older, age, baPWV, and DM are thought to be effective predictors of the amount of decrease in SBP during induction of general anesthesia.

Which nostril should be used for nasotracheal intubation: the right or left? A randomized clinical trial.

STUDY OBJECTIVE: To determine which nostril is more suitable for nasotracheal intubation in patients with normal patency of both nostrils. DESIGN: Prospective, randomized clinical trial. SETTING: Operating room of a university medical center. PATIENTS: 191 ASA physical status 1 and 2 patients scheduled for elective oral surgery requiring general anesthesia with nasotracheal intubation. INTERVENTIONS: Patients were randomized to two groups to undergo nasotracheal intubation through the right nostril (Group R; n = 96) or the left nostril (n = 95). Standard traditional nasotracheal intubation was performed using the Macintosh laryngoscope. Tube rotation was attempted for alignment toward the glottis, and Magill forceps were then used to assist intubation, as necessary. MEASUREMENTS: Epistaxis was inspected in the pharynx after the tube tip was passed through the nasal cavity and 15 minutes after nasotracheal intubation was completed. Intubation time was the interval between when the anesthesiologist opened the patient's mouth with the cross finger maneuver and when the tube was connected to the anesthetic circuit after nasotracheal completion. MAIN RESULTS: The frequency of epistaxis was significantly lower in Group R than Group L (P = 0.0006). Although there was no significant difference in nasal passage time between two groups, the intubation time in Group R (24.5 ± 9.4 sec) was shorter than in Group L (30.5 ± 15.6 sec; P = 0.0015). CONCLUSION: Nasal intubation via the right nostril is more safely performed than with the left nostril. Because of less epistaxis and faster intubation.

The effect of nitrous oxide inhalation on the hypotensive response to propofol: a randomized controlled trial.

OBJECTIVE: Decrease in arterial blood pressure is a prominent adverse reaction during propofol (Disoprivan; AstraZeneca K.K., Osaka, Japan) sedation. The purpose of this prospective randomized study was to explore the effects of nitrous oxide (N2O) on the hypotensive response during propofol sedation. STUDY DESIGN: Twenty-six healthy volunteers received intravenous sedation with propofol alone (group P, n=13) or a combined technique using 20% N2O and propofol (group N+P, n=13). Propofol was administered by a target-controlled infusion system to attain and maintain a plasma propofol concentration of 1.5µg/mL. Hemodynamic and autonomic parameters were measured. RESULTS: Mean arterial pressure decreased in both groups, the hypotensive response in group N+P being significantly smaller than in group P. Reduction in the low-frequency power of systolic blood pressure variability, indicative of sympathetic nervous activity, was also smaller in group N+P than in group P. CONCLUSIONS: Addition of N2O to propofol sedation can attenuate the hypotensive effect of propofol.

[Perioperative management of tongue reduction surgery for macroglossia associated with Beckwith-Wiedemann syndrome -A retrospective evaluation of 14 patients--].

BACKGROUND: Macroglossia is the commonest symptom of Beckwith-Wiedemann syndrome (BWS) and sometimes requires surgical tongue reduction for cosmetic, feeding, drooling and speech problems. METHODS: We retrospectively reviewed the perioperative course of 14 BWS patients. The subjects were children who underwent tongue reduction surgery or glossopexy between 1994 and 2008 at Osaka Medical Center for Maternal & Child Health. RESULTS: The median age was 18 months, and the median weight was 12.2 kg at the time of surgery. One patient had the trachea intubated and another had tracheostomy to keep airway patency. Other 12 patients had no artificial airway and were premedicated with midazolam or diazepam and had the trachea intubated after induction with sevoflurane and nitrous oxide in oxygen. Only one patient developed difficult mask ventilation for which a nasal airway was applied. No patients demonstrated difficult intubation. All without preoperative artificial airway were extubated in the OR after the surgery. One patient demonstrated hypoglycemia. Airway compromise in the two patients who was intubated or had tracheostomy prior to surgery was not alleviated by the surgery. CONCLUSIONS: Airway disorder was not alleviated by tongue reduction surgery or glossopexy.

Cough reflex under intravenous sedation during dental implant surgery is more frequent during procedures in the maxillary anterior region.

PURPOSE: The present study was performed to evaluate the incidence of cough episodes and the association between cough episodes and patient-related and site-specific parameters during implant surgery when performed under intravenous sedation. MATERIALS AND METHODS: One hundred forty-seven patients scheduled for dental implant surgeries under intravenous sedation were enrolled in this study. Heart rate, blood pressure, percutaneous oxygen saturation, and bispectral index were monitored. Sedation was induced intravenously by a bolus administration of midazolam and maintained by a continuous administration of propofol. Sedation level was adjusted to achieve scores of 3 to 4 on the Ramsay Sedation Scale. Surgical procedures were divided into 11 stages. Implant sites were labeled as right maxillary molar, maxillary anterior, left maxillary molar, right mandibular molar, mandibular anterior, and left mandibular molar sites. When coughing occurred, heart rate, blood pressure, percutaneous oxygen saturation, bispectral index, procedure being performed, and surgical site being stimulated were recorded. RESULTS: One hundred seventy-two cough episodes were observed in 97 patients (66%). Cough episodes occurred during all stages of surgery but were substantially more frequent during preparation of the implant site. The incidence of cough episodes was significantly higher at the maxillary anterior site and lowest at the right mandibular molar areas. CONCLUSION: These findings suggest that difficulties in swallowing and in the suction of intraoral fluids have variable effects at different surgical sites. Careful suction of intraoral water and an appropriate sedation level are required, especially in procedures in the maxillary anterior region.

Small bolus of esmolol effectively prevents sodium nitroprusside-induced reflex tachycardia without adversely affecting blood pressure.

PURPOSE: Hypotensive anesthesia with sodium nitroprusside (SNP) often is associated with reflex tachycardia. The purpose of this study was to investigate whether a small bolus of esmolol could counteract SNP-induced reflex tachycardia and sympathetic activation without affecting blood pressure. MATERIALS AND METHODS: Using a time-series study design, 27 healthy young patients scheduled for mandibular osteotomy were enrolled in this study. General anesthesia was maintained with 2% sevoflurane and 67% nitrous oxide in oxygen. SNP was administered to decrease the mean arterial pressure to 55 to 65 mm Hg. When heart rate (HR) increased reflexively to higher than 95 beats/min from SNP-induced hypotension, esmolol 0.5 mg/kg was given. Blood pressure and HR were measured, and the low-frequency component (0.04 to 0.15 Hz) of systolic blood pressure variability and high-frequency component (0.15 to 0.4 Hz) of HR variability were calculated to evaluate the autonomic condition. Data were analyzed using 1-way analysis of variance after multiple comparisons or t test. P < .05 was considered statistically significant. RESULTS: Of the 27 patients analyzed, 19 patients (70%) required esmolol. In these patients, SNP caused an increase in the low-frequency component of systolic blood pressure variability and a decrease in the high-frequency component of HR variability, leading to tachycardia (HR range, 95.9 ± 7.3 to 106.7 ± 7.4 beats/min; P < .001). Esmolol suppressed the effects of SNP on the low-frequency component of systolic blood pressure variability and high-frequency component of HR variability, resulting in an immediate decrease in HR to 86.9 ± 6.2 beats/min (P < .001), whereas mean arterial pressure remained unchanged. CONCLUSIONS: A small bolus of esmolol can suppress reflex tachycardia without significantly changing mean arterial pressure. Thus, esmolol restores the autonomic imbalance induced by SNP during hypotensive anesthesia.