Randomized Assessment of the Optimal Time Interval Between Programmed Intermittent Epidural Boluses When Combined With the Dural Puncture Epidural Technique for Labor Analgesia.

BACKGROUND: The dural puncture epidural (DPE) and programmed intermittent epidural bolus (PIEB) techniques are recent advances in neuraxial labor analgesia. Previous studies have investigated the PIEB optimal interval for effective analgesia when a standard epidural technique is used to initiate labor analgesia. However, it is unknown whether these findings are applicable when DPE is used. METHODS: Patients were randomized into 1 of 5 groups with PIEB intervals of 35, 40, 45, 50, or 55 minutes. Labor analgesia was initiated on request with a DPE technique by epidural injection over 2 minutes of 15 mL of ropivacaine 0.1% with sufentanil 0.5 µg/mL after a dural puncture with a 25-gauge Whitacre needle. Effective analgesia was defined as no additional requirement for a patient-controlled bolus during the first stage of labor. The PIEB interval that was effective in 50% of patients (EI50) and 90% of patients (EI90) was estimated using probit regression. RESULTS: One hundred laboring parturients received the DPE technique of whom 93 proceeded to have analgesia maintained with PIEB using 10 mL boluses of ropivacaine 0.1% and sufentanil 0.5 µg/mL. Totals of 89.5% (17/19), 84.2% (16/19), 82.4% (14/17), 52.6% (11/19), and 36.8% (7/19) of patients in groups 35, 40, 45, 50, and 55, respectively, received effective PIEB analgesia. The estimated values for EI50 and EI90 were 52.5 (95% CI, 48.4-62.6) minutes and 37.0 (95% CI, 28.4-40.9) minutes, respectively. CONCLUSION: The estimate of the PIEB optimal interval for effective analgesia after the DPE technique was comparable to that reported in previous studies when analgesia was initiated using a conventional epidural technique.

Determination of the Optimal Volume of Programmed Intermittent Epidural Bolus When Combined With the Dural Puncture Epidural Technique for Labor Analgesia: A Random-Allocation Graded Dose-Response Study.

BACKGROUND: The dural puncture epidural (DPE) and the programmed intermittent epidural bolus (PIEB) techniques are recent innovations for labor analgesia. The optimal volume of PIEB during traditional epidural analgesia has been investigated previously but it is unknown whether these findings are applicable to DPE. This study aimed to determine the optimal volume of PIEB for effective labor analgesia after initiation of analgesia using DPE. METHODS: Parturients requesting labor analgesia received dural puncture with a 25-gauge Whitacre spinal needle and then had analgesia initiated with 15 mL of ropivacaine 0.1% with sufentanil 0.5 µg/mL. Analgesia was maintained using the same solution delivered by PIEB with boluses given at a fixed interval of 40 minutes starting 1 hour after the completion of the initial epidural dose. Parturients were randomized to 1 of 4 PIEB volume groups: 6, 8, 10, or 12 mL. Effective analgesia was defined as no requirement for a patient-controlled or manual epidural bolus for 6 hours after the completion of the initial epidural dose or until full cervical dilation. The PIEB volumes for effective analgesia in 50% of parturients (EV50) and 90% of parturients (EV90) were determined using probit regression. RESULTS: The proportions of parturients with effective labor analgesia were 32%, 64%, 76%, and 96% in the 6-, 8-, 10-, and 12-mL groups, respectively. The estimated values for EV50 and EV90 were 7.1 (95% confidence interval [CI], 5.9-7.9) mL and 11.3 (95% CI, 9.9-15.2) mL, respectively. There were no differences in side effects, including hypotension, nausea and vomiting, and fetal heart rate (FHR) abnormalities among groups. CONCLUSION: Under the conditions of the study, after initiation of analgesia using DPE, the EV90 of PIEB for effective labor analgesia using ropivacaine 0.1% with sufentanil 0.5 µg/mL was approximately 11.3 mL.

Determination of the Relative Potency of Norepinephrine and Phenylephrine Given as Infusions for Preventing Hypotension During Combined Spinal-Epidural Anesthesia for Cesarean Delivery: A Randomized Up-And-Down Sequential Allocation Study.

Purpose: The relative potency of norepinephrine and phenylephrine given as boluses to treat hypotension during spinal anesthesia for cesarean delivery has been reported but few data are available for infusions. This study aimed to determine the relative potency of norepinephrine and phenylephrine when given by infusion for preventing hypotension during combined spinal-epidural anesthesia for cesarean delivery. Methods: This was a prospective, randomized, double-blind, up-and-down sequential allocation study. Patients were randomly allocated to receive a prophylactic infusion of norepinephrine or phenylephrine started immediately after induction of anesthesia. The first patients received either norepinephrine 0.1 µg/kg/min or phenylephrine 0.5 µg/kg/min. An effective infusion rate was defined when no hypotension occurred before delivery. For each subsequent patient, the norepinephrine infusion rate was decreased or increased by 0.01 µg/kg/min or the phenylephrine infusion rate was decreased or increased by 0.05 µg/kg/min according to whether the infusion was effective or ineffective respectively in the previous patient. Values for the infusion rate that was effective in preventing hypotension in 50% of patients (ED50) for norepinephrine and phenylephrine were estimated using up-and-down sequential analysis and relative potency was estimated. Probit regression was used as a backup and sensitivity analysis. Results: The ED50 values for norepinephrine and phenylephrine calculated by the up-and-down method were 0.061 (95% CI 0.054-0.068) µg/kg/min and 0.368 (95% CI 0.343-0.393) µg/kg/min respectively. The estimated relative potency ratio for ED50 for norepinephrine to phenylephrine was 6.03:1 (95% CI 5.26:1 to 6.98:1). Conclusion: Under the conditions of this study, norepinephrine given by infusion was about 6 times more potent than phenylephrine. This information is useful for clinical practice and further comparative studies of norepinephrine versus phenylephrine. Clinical Trial Registration: http://www.chictr.org.cn/showproj.aspx, identifier [ChiCTR2200056237].

The Median Effective Dose of Oxytocin Needed to Prevent Uterine Atony During Cesarean Delivery in Elderly Parturients.

PURPOSE: Oxytocin is the first-line agent to prevent and treat uterine atony during cesarean delivery (CD). We compared the effective dose in 50% of the parturients (ED50) of a prophylactic oxytocin bolus during CD in young (<35 years) and old parturients (≥35 years) using Dixon's up-and-down method. PATIENTS AND METHODS: Twenty-eight young parturients (young group) and 25 old parturients (old group) undergoing CD under combined spinal-epidural anesthesia were enrolled. The initial oxytocin bolus was 0.5 IU, with increments or decrements of 0.25 IU. Maternal adverse effects, requirement for additional uterotonic agents, and estimated blood loss were recorded. RESULTS: The ED50 for oxytocin in the old group was higher than that in the young group (1.41 IU; 95% confidence interval, 0.63-2.19) vs 0.66 IU (0.04-1.29), P < 0.001). The total oxytocin dose in the old group was higher than in the young group (5.9 ± 2.9 vs 4.1 ± 2.1 IU, P = 0.01). The estimated blood loss in the older group and young group was 401.2 ± 204.5 mL and 289.3 ± 104.6 mL, respectively (P =0.01). The overall prevalence of adverse effects was higher in the old group than in the young group (68.0% vs 21.4%, P < 0.001). CONCLUSION: The initial bolus and total requirement of oxytocin for preventing uterine atony were higher in old parturients than in young parturients during CD. Advanced maternal age may necessitate higher doses of oxytocin.

Highly selective and sensitive turn-on fluorescent sensor for detection of Al3+ based on quinoline-base Schiff base.

A new aluminum ion fluorescent probe (4-(diethylamino)-2-hydroxybenzylidene)isoquinoline-1-carbohydrazide (HL1) has been conveniently synthesized and characterized. HL1 exhibited a highly selective and pronounced enhancement for Al3+ in the fluorescence emission over other common cations by forming a 2:1 complex, with a recognition mechanism based on excited-state intramolecular proton transfer (ESIPT) and intramolecular charge transfer (ICT). The strong fluorescent emission can be observed even at ppm level concentration of the probe in the presence of Al3+ with 41 fold intensity enhancement at 545 nm. HL1 displays good linear relationship with Al3+ in the low concentration and the limit of detection is 8.08 × 10-8 mol/L. Similar molecules with different substituents on salicylaldehyde phenyl ring were synthesized for studying the structure-activity relationship. Density-functional theory (DFT) calculations are in agreement with the proposed mechanism. It is confirmed that HL1 could be used to detect Al3+ ions in real sample by fluorescence spectrometry and Al3+ ions in cells by bioimaging.

Effects of intensity-modulated radiotherapy and chemoradiotherapy on attention in patients with nasopharyngeal cancer.

This study evaluated the short-term effects of intensity-modulated radiotherapy (IMRT) and cisplatin concurrent chemo-radiotherapy (CCRT) on attention in patients with nasopharyngeal cancer (NPC). Timely detection and early prevention of cognitive decline are important in cancer patients, because long-term cognitive effects may be permanent and irreversible. Thirty-eight NPC patients treated with IMRT (17/38) or CCRT (21/38) and 38 healthy controls were recruited for the study. Neuropsychological tests were administered to each patient before treatment initiation and within a week after treatment completion. Changes in attention performance over time were evaluated using difference values (D-values). Decreased attention was already observable in patients with NPC prior to treatment. Baseline quotient scores for auditory attention, auditory and visual vigilance, and auditory speed were lower in patients treated with CCRT than in healthy controls (P=0.037, P=0.001, P=0.007, P=0.032, respectively). Auditory stamina D-values were higher in patients treated with IMRT alone (P=0.042), while full-scale response control quotient D-values were lower in patients treated with CCRT (P=0.030) than in healthy controls. Gender, depression, education, and sleep quality were each related to decreased attention and response control. Our results showed that IMRT had no negative acute effects on attention in NPC patients, while CCRT decreased response control.

[Quantum chemistry study on fluorescence spectra of four flavonoid compounds].

The semi-empirical method PHF/PM3 of quantum chemistry was used for studying the fluorescence spectra of four flavonoid compounds. Firstly, the geometries of these four compounds were optimized by energy gradient method. The results show that in these four copmounds, the two six-membered rings on the left are in the same plane, but these are different torsion angles between this plane and the benzene-ring plane on the right. Secondly, vibrational analyses were performed for the four optimized configurations. There is no imaginary frequency in vibrational analyses. This indicates that the optimized configurations are essentially reasonable. Finally, on this basis, the electronic spectra were calculated by CIS method. All the calculated results are basically consistent with experimental values.

[Quantum chemistry study on fluorescence spectra of three flavonoid compounds].

A theoretical study on three flavonoid compounds by semi-empirical method is presented in the present paper. Their geometric configurations were optimized by the semi-empirical method RHF/PM3. For all the optimal configurations, there is no imaginary frequency in vibrational analyses. On this basis, the electronic spectra were calculated by CIS method. All the calculated results are basically consistent with experimental values.

[Resonance light scattering of quercetin].

Resonance light scattering(RLS) and absorption spectra of Quercetin were studied in the present paper. In the solution with pH 3.30 to pH 6.50, the RLS singal was very strong and stable, but decreased sharply with a increase in pH when pH > 6.50. In the B-R buffer solution at pH 4.00, the RLS intensity at 497 nm was maximum and proportional to the concentration of quercetin. The linear range is 0.0-3.0 x 10(-4) mol x L(-1) with the detection limit of 3.1 x 10(-7) mol x L(-1). Quantum chemistry calculation showed that this enhancement of RLS occurred because the neutral molecules of quercetin assembled into super-molecular aggregates by 4-4' hydrogen-bond. This result completely accords with the spectral data from experiments.