We report a case of epidural anesthesia in a patient presenting for cesarean section with Moyamoya disease. Epidural anesthesia was performed using 0.5% bupivacaine and fentanyl 100 microgram. We used NIRS (near infrared spectroscopy) to monitor neurologic complication. A stable hemodynamic state was produced using left lateral uterine displacement, i.v. infusion of crystalloid solution and ephedrine. The patient had no neurological deficit and there was no significant intraoperative decrease in cerebral oxygenation measured by near infrared spectroscopy.
Anesthesia, Epidural* ; Bupivacaine ; Cesarean Section* ; Ephedrine ; Female ; Fentanyl ; Hemodynamics ; Humans ; Moyamoya Disease* ; Oxygen ; Pregnancy ; Spectrum Analysis

In recent years, the types and quantities of fentanyl analogs have increased rapidly. It has become a hotspot in the illicit drug control field of how to quickly identify novel fentanyl analogs and to shorten the blank regulatory period. At present, the identification methods of fentanyl analogs that have been developed mostly rely on reference materials to target fentanyl analogs or their metabolites with known chemical structures, but these methods face challenges when analyzing new compounds with unknown structures. In recent years, emerging machine learning technology can quickly and automatically extract valuable features from massive data, which provides inspiration for the non-targeted screening of fentanyl analogs. For example, the wide application of instruments like Raman spectroscopy, nuclear magnetic resonance spectroscopy, high resolution mass spectrometry, and other instruments can maximize the mining of the characteristic data related to fentanyl analogs in samples. Combining this data with an appropriate machine learning model, researchers may create a variety of high-performance non-targeted fentanyl identification methods. This paper reviews the recent research on the application of machine learning assisted non-targeted screening strategy for the identification of fentanyl analogs, and looks forward to the future development trend in this field.
Fentanyl ; Substance Abuse Detection/methods* ; Mass Spectrometry/methods* ; Illicit Drugs/analysis*

BACKGROUND: In general, we know that a thoracic sympathicotomy may have influence an cardiac autonomic nervous activity to change vital signs. The purpose of this study was to analyse preoperative and postoperative heart rate variability to evaluate the influence of a sympathicotomy on cardiac autonomic activity. METHODS: We studied 14 healthy patients, ASA physical status I and II, undergoing an endoscopic thoracic sympathicotomy. A laryngeal airway mask was performed on all patients for tracheal intubation. Intravenous anesthesia was induced by administration of propofol 10 mg/kg, and fentanyl 2ng/kg and was maintained with propofol 10ng/kg/hr and N2O-O2 (2 L/min-2 L/min). An electrocardiogram was checked in the supine position with Biopac Student Lab. at an hour before anesthetic induction, after a left and right sympathicotomy and at 3 - 4 hours after emergence. A spike 2 version 3.0 was used for analyzing heart rate variability and a Fast Fourier Transform was used to yield a power spectrum. Frequency bands were divided to low frequency (0.02 - 0.09 Hz), middle frequency (0.1 - 0.15 Hz), and high frequency (0.16 - 1.0 Hz) components. RESULTS: There were no significant changes of heart rate, high frequency component, low frequency component and ratio of low to high frequency component. CONCLUSIONS: Influence of a thoracic sympathicotomy on cardiac autonomic activity was less in the supine position at rest. However, we think that the response of the cardiac autonomic activity to sympathetic stimulation like position change and exercise after a sympathicotomy may yield different results and studies about this must be done.
Anesthesia, Intravenous ; Electrocardiography ; Fentanyl ; Fourier Analysis ; Heart Rate* ; Heart* ; Humans ; Intubation ; Masks ; Propofol ; Supine Position ; Vital Signs

OBJECTIVETo investigate the effect of dexmedetomidine on oxygenation function in adult patients with balanced anesthesia by propofol-fentanyl under one-lung ventilation (OLV).

METHODSTwenty-two patients undergoing thoracic operation were randomly divided into the study group and control group, both receiving propofol and fentanyl balanced anesthesia. In the study group, additional infusion of dexmedetomidine (0.3 µg/kg loading dose, 0.3 µg·kg(-1)·h(-1) maintenance dose) was administered, and the patients in the control group received only normal saline. Arterial blood samples were obtained at 4 time points from each patient during anesthesia for blood gas analysis.

RESULTSIn the study group, the pH values remained stable, the oxygenation index tended to decline progressively, but the incidence of hypoxemia was low; in the control group, the pH value and oxygenation index both declined progressively with a higher incidence of hypoxemia.

CONCLUSIONDexmedetomidine can better maintain the oxygenation function of OLV patients in balanced anesthesia by propofol and fentanyl, and its mechanism may be related to the decreased dose of propofol used.

Adult ; Balanced Anesthesia ; Blood Gas Analysis ; Dexmedetomidine ; pharmacology ; Female ; Fentanyl ; Humans ; Male ; Middle Aged ; One-Lung Ventilation ; Propofol

We replaced anesthesia of operations, which has done under local or general anesthesia, by MAC(monitored anesthesia care) with various patient's monitoring devices such as BIS(bispectral index). From April 2003 to March 2004, 48 cases of operations were done in MAC with supplemental equipments. Induction, maintenance of anesthesia was performed by propofol and midazolam. Pain control was done by fentanyl and ketamine. For monitoring the depth of anesthesia in real time, and BIS scale was checked and was maintained in 40-60. All anesthesias were done by the anesthesiologist that was communicated with operator for information between patient's status and operation procedures. All operations and anesthesias progressed with stability and safety, and there was no major postoperative complication. Because BIS was relatively accurate device, there was no over dose of anesthetic agents, which was induced by patient's uncertain pain complain under sedation and no anxiety of operator, that was raised by no responsive patient. BIS made possible that operation under MAC was effective and safe, operator perform it with non-stress condition and followed by good surgical result.
Anesthesia* ; Anesthesia, General ; Anesthesia, Intravenous ; Anesthetics ; Anxiety ; Conscious Sedation* ; Fentanyl ; Humans ; Ketamine ; Midazolam ; Postoperative Complications ; Propofol ; Spectrum Analysis ; Surgery, Plastic*

Objective To provide the reference for the identification of unknown fentanyl analogues by studying the characteristic ions and main fragmentation pathways of fentanyl analogues in the modes of collision induced dissociation （CID） and electron ionization （EI）. Methods Nine fentanyl analogues （2, 2'-difluorofentanyl, acetyl fentanyl, fentanyl, butyl fentanyl, valeryl fentanyl, acryloyl fentanyl, furan fentanyl, 4-fluorine isobutyl fentanyl, carfentanyl） were selected and analyzed with ultra-high performance liquid chromatography-quadrupole time-of-flight-mass spectrometry （UHPLC-QTOF-MS） and gas chromatography-mass spectrometry （GC-MS）. The mass spectrum obtained was analyzed. The CID and EI fragmentation routes of fentanyl analogues were speculated. Results The CID and EI fragmentation pathways were highly similar. In the CID mode, characteristic ions were formed by the carbon-nitrogen bond cleavage between the piperidine ring and the N-phenyl-amide moiety, within the piperidine ring, and between the phenethyl and piperidine ring. While in the EI mode, dissociation of the piperidine ring, as well as cleavage between the piperidine ring and the phenethyl were the main fragmentation pathways. Conclusion This study summarizes the main fragmentation pathways and characteristic ions of fentanyl analogues in the CID and EI modes, which is useful for forensic laboratories to identify and structural analyze fentanyl type new psychoactive substance in practical work.
Chemistry Techniques, Analytical/methods* ; Chromatography, High Pressure Liquid ; Fentanyl/analysis* ; Gas Chromatography-Mass Spectrometry ; Humans ; Mass Spectrometry

BACKGROUNDOpioid switching is a therapeutic maneuver to improve analgesic response and/or reduce adverse side effects although the underlying mechanisms remain unknown. The µ-opioid receptor (MOR) has an important role in mediating the actions of morphine and other analgesic agents. This study is aimed at exploring the changes of MOR in the periaqueductal gray (PAG) in rats when morphine is substituted for equianalgesic fentanyl.

METHODSForty rats were randomly assigned to five treatment groups: 7 days normal saline group (N group), 7 days fentanyl group (F group), 7 days morphine group (M group), 7 days morphine and 7 days fentanyl-switching group (MF group), and 14 days morphine group (MM group). Rats repeatedly received subcutaneous injections of morphine sulfate (10 mg/kg) or equianalgesic fentanyl sulfate (0.1 mg/kg) twice daily. Rats' antinociceptive response to thermal pain was evaluated by the tail flick latency assay. MOR mRNA and protein expression in the PAG were measured using RT-PCR and Western blotting analyses respectively.

RESULTSThis study showed that after morphine was substituted with fentanyl on day 8, the tail flick latency (TFL) increased from (3.9 ± 0.4) seconds to (11.4 ± 0.4) seconds. The results also demonstrated that both MOR mRNA and protein expression in the PAG of rats in the MF group were less than that in the M group (P < 0.05) but more than that in MM group (P < 0.05).

CONCLUSIONSEquianalgesic fentanyl was still antinociceptive effective in rats with morphine tolerance, which may be due to the switching from morphine to fentanyl attenuating the decline of MOR expression in the PAG of rats.

Analgesics, Opioid ; pharmacology ; Animals ; Drug Tolerance ; Fentanyl ; pharmacology ; Male ; Morphine ; pharmacology ; Periaqueductal Gray ; chemistry ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Receptors, Opioid, mu ; analysis ; genetics

High frequency jet ventilation(HFJV) administered through a thin catheter instead of a standard endotracheal tube provides improved operation field during laryngeal microsurgery. In this study, effect of changes in inspiration time and frequency on gas exchange was observed. Sixty five patients(ASA class 1-2) underwent laryngeal microsurgery were divided into 3 groups according to inspiration time(50%, 40% and 30%) and then subdivided into 3 groups according to frequency(3.3 Hz, 2.5 Hz and 1.7 Hz). Driving pressure was same in all groups(2.4 kg, cm). Anesthesia was induced with thiopental sodium, fentanyl and succinylcholine with 100% oxygen mask ventilation and maintained with intermittent intravenous anesthetics during jet ventilation via 10 Fr. catheter with 100% oxygen. Jet cannular was located 1 cm proximal to carina. Arterial blood gas analysis and hemodynamic data(blood pressure and heart rate) were measured at 0 minute(just after catheter intubated and jet ventilation started), 5 minute, 10 minute and after then, every 10 minutes. There was significant change in PaCO; by varing inspiration time but, no significant change by frequency except in group of 3.3 Hz at inspiration time 40% and 30%. Number of patients who showed in excess of 45 mmHg of PaCO2 at 20 minute were 2 out of 19, 9 out of 23 and 9 out of 23 in inspiration time 50%, 40% and 30%, respectively. In summary, HFJV via thin catheter located 1 cm proximal to carina during laryngeal microsurgery can be done safely with inspiration time 50% under good operation field at driving pressure 2.4 kg/cm and frequency 3.3, 2.5 and 1.7 Hz.
Anesthesia ; Anesthetics, Intravenous ; Blood Gas Analysis ; Catheters ; Fentanyl ; Heart ; Hemodynamics ; High-Frequency Jet Ventilation* ; Humans ; Masks ; Microsurgery* ; Oxygen ; Succinylcholine ; Thiopental ; Ventilation

BACKGROUND: Significant analgesic synergy is obtained when opioids are combined with dilute local anesthetics, but serious side effects of intraspinal opioid can develope. The purpose of this study was to see how much does additional fentanyl make change of hemodynamics and analgesic dermatome according to variation of local anesthetic concentration. METHODS: Thirty patients were divided into three groups who were receiving epidurally 0.33% bupivacaine 15 ml(group 1), 0.33% bupivacaine 15 ml including fentanyl 100 g(group 2), 0.25% bupivacaine 15 ml including fentanyl 100 g(group 3) at the C7-T1 interspace. We observed mean arterial blood pressure, pulse rate and arterial blood gas analysis to be changed. Evaluation of the onset and duration of analgesic action by pin prick test were taken. Also side effects and complications were checked. RESULTS: Decreases of mean arterial blood pressure was statistically significant between 10 and 120 minutes in group 1, between 10 and 50 minutes in group 2, between 10 and 40 minutes in group 3 after drug administration. Decreases of pH and increases of PaCO2 were statistically significant between 30 and 60 minutes in group 1, between 30 and 120 minutes in group 2, 3 after drug administration. In three groups, number of analgesic dermatome was maximal at 40 minutes after drug administraion. The duration of analgesia in C8 dermatome was 153 29 minutes in group 1, 168 21 minutes in group 2, 131 31 minutes in group 3. Inadvertant dural puncture was developed in one patient. Transient pruritus, nausea/vomiting and solmnolence were developed in group 2, 3. CONCLUSIONS: Three groups provided sufficient analgesia for operation. fentanyl affects on hemodynamics, ventilation but not on number of maximal analgesic dermatome. Also it produces side effects such as, mild pruritus, somnolence, nausea/vomiting.
Analgesia ; Analgesics, Opioid ; Anesthesia, Epidural* ; Anesthetics ; Anesthetics, Local ; Arterial Pressure ; Blood Gas Analysis ; Bupivacaine* ; Fentanyl ; Heart Rate ; Hemodynamics ; Humans ; Hydrogen-Ion Concentration ; Pruritus ; Punctures ; Ventilation

BACKGROUND: The combination of ketamine and propofol, fentanyl and propofol has been used for anesthesia induction and total intravenous anesthesia. Advantages of using the combination have included hemodynamic stability intraoperatively and superior analgesia. METHODS: Forty patients (ASA physical status 1, 2) scheduled for cesarean section were randomized to either propofol-fentanyl (n=20) (P-F) or propofol-ketamine (n=20) (P-K) group. We checked to the cardiovascular effects of anesthetic induction, neonatal outcome, and maternal recovery time during cesarean section. RESULTS: There were no significant differences in systolic and mean arterial pressure in both groups. Diastolic arterial pressure was increased significantly in both groups at intubation, but degree of increase was less in P-F group. The Apgar scores of the newborn and blood gas analysis of umbilical vein were not significantly different in both groups. Maternal recovery from anesthesia was significantly quicker in P-F group. CONCLUSIONS: Propofol infusion coupled with fentanyl or ketamine would provide good anesthesia instead of inhalational anesthesia for cesarean section without significant adverse effects on both mother and fetus. However, recovery from anesthesia was faster and cardiovascular changes were less with P-F than P-K group.
Analgesia ; Anesthesia* ; Anesthesia, Intravenous ; Anesthetics ; Arterial Pressure ; Blood Gas Analysis ; Cesarean Section* ; Female ; Fentanyl ; Fetus ; Hemodynamics ; Humans ; Infant, Newborn ; Intubation ; Ketamine ; Mothers ; Pregnancy ; Propofol ; Umbilical Veins