The influence of neuromuscular blockade on phase lag entropy and bispectral index: A randomized, controlled trial.

The aim of this study is to compare the effects of neuromuscular blockade (NMB) on phase lag entropy (PLE) and the bispectral index (BIS). We recorded the BIS, electromyograph (EMG) activity on a BIS monitor (EMG_BIS), PLE, and EMG activity on a PLE monitor (EMG_PLE) in 40 patients receiving general anesthesia. During the awake state, we analyzed the changes in parameters before and 2 min after the eyes were closed. During sedation, we compared the changes in the parameters before and at 4 min after injecting rocuronium (group R) or normal saline (group C) between the two groups. During anesthesia, we compared the changes in parameters before and at 4 min after injecting sugammadex (group B) or normal saline (group D) between the two groups. During the awake state, the BIS, EMG_BIS, and EMG_PLE, but not PLE, decreased significantly with closed eyes. An effect of EMG on the BIS was evident, but not on PLE. During sedation, the BIS decreased with the decrease in EMG_BIS regardless of NMB caused by rocuronium, but NMB decreased PLE, although the degree of the decrease in EMG_PLE after NMB was similar to that after placebo. To determine the effect of NMB on electroencephalograms (EEGs) in groups R and C, we plotted the power spectra before and at 4 min after injecting rocuronium or normal saline. Changes in slow and delta frequency bands were observed at 4 min after injecting rocuronium relative to before injecting rocuronium. There was no effect of EMG on either the BIS or PLE during anesthesia. In conclusion, the effect of electromyograph activity and/or neuromuscular blockade on BIS or PLE depends on the level of consciousness.

Factors Affecting Maternal and Fetal Outcomes of Non-Obstetric Surgery and Anesthesia during Pregnancy: a Retrospective Review of Data at a Single Tertiary University Hospital.

BACKGROUND: Anesthesia during pregnancy for non-obstetric surgery is generally known to have a negative impact on maternal and fetal outcomes. We assessed the risk of adverse outcomes in fetuses and mothers associated with non-obstetric surgery. METHODS: This retrospective study analyzed clinical data on pregnant women who received non-obstetric surgeries at a tertiary university hospital. We reviewed maternity admissions using hospital administrative data during the last 16 years. The outcome assessment included the presence of preterm labor, premature birth, abortion, or stillbirth and the data of newborns. Statistical analyses were performed using the t-test, χ² test, and multiple logistic regression was used for risk analysis. RESULTS: The incidence of non-obstetric surgery during pregnancy was 0.96%. Gestational age at or above 20 weeks increased the risk of all adverse events 4.5 fold when it was compared to gestational age less than 20 weeks, although the events were only preterm labor or premature birth and no fetal loss. All fetal loss cases occurred in patients at less than 20 weeks of pregnancy. The risk of adverse outcome increased by 2% for every 1 minute increase in anesthesia time. Babies of the mothers who had the adverse outcome event showed lower birth weight and higher neonatal intensive care unit admission rate than those of babies of the mothers without any adverse event after the surgery. CONCLUSION: Physicians should acknowledge and prepare for common possible adverse events at the stage of pregnancy after non-obstetric surgery, and effort to shorten the duration of surgery and anesthesia is needed.

Heparin-free veno-venous extracorporeal membrane oxygenation in a multiple trauma patient: A case report.

RATIONALE: Extracorporeal membrane oxygenation (ECMO) in multiple trauma patients with post-traumatic respiratory failure can be quite challenging because of the need for systemic anticoagulation, which may lead to excessive bleeding. In the last decade, there is a growing body of evidence that veno-venous ECMO (VV-ECMO) is lifesaving in multiple trauma patients with acute respiratory distress syndrome, thanks to technical improvements in ECMO devices. PATIENT CONCERNS: We report a case of a 17-year-old multiple trauma patient who was drunken and had confused mentality. DIAGNOSES: She was suffered from critical respiratory failure (life-threatening hypoxemia and severe hypercapnia/acidosis lasting for 70 minutes) accompanied by cardiac arrest and trauma-induced coagulopathy during general anesthesia. INTERVENTIONS: We decided to start heparin-free VV-ECMO after cardiac arrest considering risk of hemorrhage. OUTCOMES: She survived with no neurologic sequelae after immediate treatment with heparin-free VV-ECMO. LESSONS: Heparin-free VV-ECMO can be used as a resuscitative therapy in multiple trauma patients with critical respiratory failure accompanied by coagulopathy. Even in cases in which life-threatening hypoxemia and severe hypercapnia/acidosis last for >1 hours during CPR for cardiac arrest, VV-ECMO could be considered a potential lifesaving treatment.

The tidal volume challenge improves the reliability of dynamic preload indices during robot-assisted laparoscopic surgery in the Trendelenburg position with lung-protective ventilation.

BACKGROUND: The reliability of pulse pressure variation (PPV) and stroke volume variation (SVV) is controversial under pneumoperitoneum. In addition, the usefulness of these indices is being called into question with the increasing adoption of lung-protective ventilation using low tidal volume (VT) in surgical patients. A recent study indicated that changes in PPV or SVV obtained by transiently increasing VT (VT challenge) accurately predicted fluid responsiveness even in critically ill patients receiving low VT. We evaluated whether the changes in PPV and SVV induced by a VT challenge predicted fluid responsiveness during pneumoperitoneum. METHODS: We performed an interventional prospective study in patients undergoing robot-assisted laparoscopic surgery in the Trendelenburg position under lung-protective ventilation. PPV, SVV, and the stroke volume index (SVI) were measured at a VT of 6 mL/kg and 3 min after increasing the VT to 8 mL/kg. The VT was reduced to 6 mL/kg, and measurements were performed before and 5 min after volume expansion (infusing 6% hydroxyethyl starch 6 ml/kg over 10 min). Fluid responsiveness was defined as ≥15% increase in the SVI. RESULTS: Twenty-four of the 38 patients enrolled in the study were responders. In the receiver operating characteristic curve analysis, an increase in PPV > 1% after the VT challenge showed excellent predictive capability for fluid responsiveness, with an area under the curve (AUC) of 0.95 [95% confidence interval (CI), 0.83-0.99, P < 0.0001; sensitivity 92%, specificity 86%]. An increase in SVV > 2% after the VT challenge predicted fluid responsiveness, but showed only fair predictive capability, with an AUC of 0.76 (95% CI, 0.60-0.89, P < 0.0006; sensitivity 46%, specificity 100%). The augmented values of PPV and SVV following VT challenge also showed the improved predictability of fluid responsiveness compared to PPV and SVV values (as measured by VT) of 6 ml/kg. CONCLUSIONS: The change in PPV following the VT challenge has excellent reliability in predicting fluid responsiveness in our surgical population. The change in SVV and augmented values of PPV and SVV following this test are also reliable. TRIAL REGISTRATION: This trial was registered with Clinicaltrials.gov, NCT03467711 , 10th March 2018.

Ultrasound measurement of the vertebral level of Tuffier's line in elderly women.

BACKGROUND: It would be imprecise to generalize the vertebral level determined by palpation to patients of all ages. The purpose of this study was to compare the vertebral level passed by Tuffier's line in elderly women with that passed in adult women using ultrasound in the left lateral decubitus flexed position. METHODS: We enrolled 50 female patients over the age of 65 (elderly group) and 50 female patients between ages 20 and 50 (control group) who had been scheduled to undergo spinal anesthesia. Using ultrasound, we marked the L2-5 lumbar spinous processes and intervertebral spaces. The most cephalad part was labeled 1 and the most caudal part was labeled 11. We then identified which line of these vertebral levels Tuffier's line crossed. RESULTS: The median value of the numbers signifying the vertebral level of Tuffier's line was 3 (the L2-3 intervertebral space) in the elderly group, while it was 8 (the lower part of the L4 vertebra) in the control group. The vertebral level of Tuffier's line had statistically significant correlations with age, body mass index, and weight in the elderly group (P < 0.001). CONCLUSIONS: The vertebral level of Tuffier's line determined with ultrasound measurement in the left lateral decubitus flexed position was more cephalad in the elderly women than in those of the control group. Therefore, we should consider that the needle could be inserted at a higher level than expected, and use care in determining the level of needle insertion during spinal anesthesia in elderly women.

Dexmedetomidine-ketamine versus Dexmedetomidine-midazolam-fentanyl for monitored anesthesia care during chemoport insertion: a Prospective Randomized Study.

BACKGROUND: Dexmedetomidine as a sole agent showed limited use for painful procedures due to its insufficient sedative/analgesic effect, pronounced hemodynamic instability and prolonged recovery. The aim of this study was to compare the effects of dexmedetomidine-ketamine (DK) versus dexmedetomidine-midazolam-fentanyl (DMF) combination on the quality of sedation/analgesia and recovery profiles for monitored anesthesia care (MAC). METHODS: Fifty six patients undergoing chemoport insertion were randomly assigned to group DK or DMF. All patients received 1 µg.kg(-1) dexmedetomidine over 10 min followed by 0.2-1.0 µg.kg(-1)h(-1) in order to maintain 3 or 4 of modified Observer's Assessment of Analgesia and Sedation score checked every 3 min. At the start of dexmedetomidine infusion, patients in group DK or DMF received 0.5 mg.kg(-1) ketamine or 0.05 mg.kg(-1) midazolam + 0.5 µg.kg(-1) fentanyl intravenously, respectively. When required, rescue sedatives (0.5 mg.kg-1 of ketamine or 0.05 mg.kg-1 of midazolam) and analgesics (0.5 mg.kg-1 of ketamine or 0.5 µg.kg-1 of fentanyl) were given to the patients in DK or DMF group, respectively. The primary outcome of this study was the recovery parameters (time to spontaneous eye opening and the length of the recovery room stay). The secondary outcomes were parameters indicating quality of sedation/analgesia, cardiorespiratory variables, and satisfaction scores. RESULTS: There were no significant differences in the onset time, time to spontaneous eye opening, recovery room stay, the incidences of inadequate analgesia, hypotension and bradycardia between the two groups. Despite lower infusion rate of dexmedetomidine, more patients in the DMF group had bispectral index (BIS) < 60 than in the DK group and vice versa for need of rescue sedatives. The satisfaction scores of patients, surgeon, and anesthesiologist in the DMF group were significantly better than the DK group. CONCLUSIONS: The DK and DMF groups showed comparable recovery time, onset time, cardiorespiratory variables, and analgesia. However, the DMF group showed a better sedation quality and satisfaction scores despite the lower infusion rate of dexmedetomidine, and a higher incidence of BIS < 60 than the DK group. TRIAL REGISTRATION: Clinical Trial Registry of Korea KCT0000951 , registered 12/12/2013.

Airway management in patients with deep neck infections: A retrospective analysis.

Securing the airway in patients undergoing surgical intervention to control a deep neck infection (DNI) is challenging for anesthesiologists due to the distorted airway anatomy, limited mouth opening, tissue edema, and immobility. It is critical to assess the risk of a potential difficult airway and prepare the most appropriate airway management method.We reviewed our anesthetic experiences managing patients with DNIs, focusing on the need for video-laryngoscope or awake fiberoptic intubation beyond a standard intubation from the anesthesiologist's perspective.When patients had infections in the masticatory space, mouth of floor, oropharyngeal mucosal space, or laryngopharynx, their airways tended to be managed using methods requiring more effort by the anesthesiologists, and more extensive equipment preparation, compared with use of a standard laryngoscope. The degree to which the main lesion influenced the airway anatomy, especially at the level of epiglottis and aryepiglottic fold was related to the airway management method selected.When managing the airways of patients undergoing surgery for DNIs under general anesthesia, anesthesiologists should use imaging with computed tomography to evaluate the preoperative airway status and a comprehensive understanding of radiological findings, comorbidities, and patients' symptoms is needed.

Percutaneous Sacroplasty under Fluoroscopic Guidance Combined with Epidurogram for Sacral Insufficiency Fracture Resulting from Metastatic Tumor and Osteoporosis.

Sacral insufficiency fracture resulting from a metastatic tumor or an osteoporotic fracture causes severe low back pain and radiating pain mass effect on neural foramen and chemical irritants. Percutaneous sacroplasty is one of the effective treatment modalities for sacral insufficiency fracture and its pain. Because of the structural complexity of the sacrum, obtaining an epidurogram of the S1 and S2 nerve roots before the start of the procedure can be helpful to avoid nerve injury. We present 2 successful cases of percutaneous sacroplasty performed under fluoroscopic guidance. A 65-year-old man with sacral metastasis from stomach cancer and a 52-year-old man with sacral insufficiency fracture were suffering from severe buttock pain and radiating pain. After epidurography of the S1 and S2 nerve roots with steroid and contrast dye, percutaneous sacroplasty with fluoroscopy on the S1 or S2 body and alae was performed on both patients. There was no cement leakage or any other major complications. Both patients experienced significant reduction in pain.

Effect of Propofol and Desflurane on Immune Cell Populations in Breast Cancer Patients: A Randomized Trial.

Several factors can affect the perioperative immune function. We evaluated the effect of propofol and desflurane anesthesia on the surgery-induced immune perturbation in patients undergoing breast cancer surgery. The patients were randomly assigned to receive propofol (n = 20) or desflurane (n = 20) anesthesia. The total and differential white blood cell counts were determined with lymphocyte subpopulations before and 1 hr after anesthesia induction and at 24 hr postoperatively. Plasma concentrations of interleukin (IL)-2 and IL-4 were also measured. Both propofol and desflurane anesthesia preserved the IL-2/IL-4 and CD4(+)/CD8(+) T cell ratio. Leukocytes were lower in the propofol group than in the desflurane group at 1 hr after induction (median [quartiles], 4.98 [3.87-6.31] vs. 5.84 [5.18-7.94] 10(3)/µL) and 24 hr postoperatively (6.92 [5.54-6.86] vs. 7.62 [6.22-9.21] 10(3)/µL). NK cells significantly decreased 1 hr after induction in the propofol group (0.41 [0.34-0.53] to 0.25 [0.21-0.33] 10(3)/µL), but not in the desflurane group (0.33 [0.29-0.48] to 0.38 [0.30-0.56] 10(3)/µL). Our findings indicate that both propofol and desflurane anesthesia for breast cancer surgery induce a favorable immune response in terms of preservation of IL-2/IL-4 and CD4(+)/CD8(+) T cell ratio in the perioperative period. With respect to leukocytes and NK cells, desflurane anesthesia is associated with less adverse immune responses than propofol anesthesia during surgery for breast cancer. (Clinical trial registration at https://cris.nih.go.kr/cris number: KCT0000939).

Doxepin and imipramine but not fluoxetine reduce the activity of the rat glutamate transporter EAAT3 expressed in Xenopus oocytes.

BACKGROUND: Many researchers have suggested that the glutamatergic system may be involved in the effects of antidepressant therapies. We investigated the effects of doxepin, imipramine, and fluoxetine on the excitatory amino acid transporter type 3 (EAAT3). METHODS: EAAT3 was expressed in Xenopus oocytes by injection of EAAT3 mRNA. Membrane currents were recorded after application of L-glutamate (30 µM) in the presence or absence of various concentrations of doxepin, imipramine, and fluoxetine. To study the effects of protein kinase C (PKC) activation on EAAT3 activity, oocytes were pre-incubated with phorbol 12-myristate-13-acetate (PMA) before application of imipramine and doxepin. RESULTS: Doxepin at 0.063-1.58 µM significantly decreased EAAT3 activity. Imipramine reduced EAAT3 activity in a concentration-dependent manner at 0.16-0.95 µM. However, fluoxetine did not affect EAAT3 activity, and PMA increased EAAT3 activity. At 0.32 µM, imipramine caused an equivalent decrease in EAAT3 activity in the presence or absence of PMA. However, 0.79 µM doxepin did not abolish the enhancement of EAAT3 activity by PMA. CONCLUSIONS: We showed that doxepin and imipramine, but not fluoxetine, inhibited EAAT3 activity at clinically relevant concentrations. This reveals a novel mechanism of action for doxepin and imipramine; that they increase glutamatergic neurotransmission. PKC may be involved in the effects of doxepin on EAAT3, but is not involved in the effects of imipramine at the concentrations studied.

The degree of labor pain at the time of epidural analgesia in nulliparous women influences the obstetric outcome.

BACKGROUND: The increased pain at the latent phase can be associated with dysfunctional labor as well as increases in cesarean delivery frequency. We aimed to research the effect of the degree of pain at the time of epidural analgesia on the entire labor process including the mode of delivery. METHODS: We performed epidural analgesia to 102 nulliparous women on patients' request. We divided the group into three based on NRS (numeric rating scale) at the moment of epidural analgesia; mild pain, NRS 1-4; moderate pain, NRS 5-7; severe pain, NRS 8-10. The primary outcome was the mode of delivery (normal labor or cesarean delivery). RESULTS: There were significant differences in the mode of delivery among groups. Patients with severe labor pain had a significantly higher cesarean delivery compared to patients with moderate labor pain (P = 0.006). The duration of the first and second stage of labor, fetal heart rate, use of oxytocin and premature rupture of membranes had no differences in the three groups. CONCLUSIONS: Our research showed that the degree of pain at the time of epidural analgesia request might influence the rate of cesarean delivery. Further research would be necessary for clarifying the mechanism that the augmentation of pain affects the mode of delivery.

Hydrothorax with alveolar-pleural fistula mimicking re-expansion pulmonary edema during liver transplantation: a case report.

We present a case of an alveolar-pleural fistula with hepatic hydrothorax in a patient undergoing orthotropic liver transplantation, which was detected by drainage of transudate through an endotracheal tube during operation. A standard endotracheal tube was changed to a double-lumen tube to provide differential lung ventilation. The patient was diagnosed with an alveolar-pleural fistula by direct vision of an air leak during positive-pressure ventilation through a diaphragmatic incision. There was still a concern about worsening his ventilation due to persistent aspiration of pleural effusion towards the ipsilateral lung during the remaining operation period. Surgeon repaired the defect on the exposed lung surface via diaphragmatic opening. Anesthesiologists should consider an alveolar-pleural fistula as a possible differential diagnosis with re-expansion pulmonary edema when transudate emanating from the endotracheal tube is obtained in patients with massive hydrothorax.

Is small tidal volume with low positive end expiratory pressure during one-lung ventilation an effective ventilation method for endoscopic thoracic surgery?

BACKGROUND: The present study will focus on the rationale for the use of small tidal volume with 6 cmH2O positive end expiratory pressure (PEEP) with the changes of arterial oxygen tension, plateau airway pressure, and static lung compliance during one lung ventilation for endoscopic thoracic surgery. METHODS: Forty-three patients were intubated with a double-lumen endobronchial tube. After positioning the patients in the lateral decubitus, one-lung ventilation was started with 100% oxygen, tidal volume 10 ml/kg without PEEP; arterial oxygen tension, plateau airway pressure, and static compliance were checked as baseline values (T0). Fifteen minutes later, same parameters were measured (T15). The tidal volume had changed to 6 ml/kg with 6 cmH2O PEEP. Fifteen minutes later, the same parameters were measured (T30). RESULTS: Oxygen tension had decreased at T15 (282.1 ± 83.4 mmHg) compared to T0 (477.2 ± 82.4 mmHg) (P < 0.0001), but was maintained at T30 (270.4 ± 81.9 mmHg). There was no difference in peak inspiratory pressure at T15 or T30 compared to T0, plateau airway pressure was increased at T15 and T30 (P < 0.05) and static lung compliance was decreased at T15 and T30 (P < 0.0001). CONCLUSIONS: In carrying out one-lung ventilation for thoracic surgery using an endoscope, the addition of a PEEP of 6 cmH2O in the dependent lung, while reducing the tidal volume of 6 ml/kg, both oxygen tension and lung compliance are maintained without increasing the plateau airway pressure. Protective lung ventilation is useful for one lung ventilation.

Does intravenous ketamine enhance analgesia after arthroscopic shoulder surgery with ultrasound guided single-injection interscalene block?: a randomized, prospective, double-blind trial.

Ketamine has anti-inflammatory, analgesic and antihyperalgesic effect and prevents pain associated with wind-up. We investigated whether low doses of ketamine infusion during general anesthesia combined with single-shot interscalene nerve block (SSISB) would potentiate analgesic effect of SSISB. Forty adult patients scheduled for elective arthroscopic shoulder surgery were enrolled and randomized to either the control group or the ketamine group. All patients underwent SSISB and followed by general anesthesia. During an operation, intravenous ketamine was infused to the patients of ketamine group continuously. In control group, patients received normal saline in volumes equivalent to ketamine infusions. Pain score by numeric rating scale was similar between groups at 1, 6, 12, 24, 36, and 48 hr following surgery, which was maintained lower than 3 in both groups. The time to first analgesic request after admission on post-anesthesia care unit was also not significantly different between groups. Intraoperative low dose ketamine did not decrease acute postoperative pain after arthroscopic shoulder surgery with a preincisional ultrasound guided SSISB. The preventive analgesic effect of ketamine could be mitigated by SSISB, which remains one of the most effective methods of pain relief after arthroscopic shoulder surgery.

Clinical comparisons of 0.5% and 0.375% levobupivacaine for ultrasound-guided axillary brachial plexus block with nerve stimulation.

BACKGROUND: In an axillary brachial plexus block (ABPB), where relatively large doses of local anesthetics are administered, levobupivacaine is preferred due to a greater margin of safety. However, the efficacy of levobupivacaine in ABPB has not been studied much. We performed a prospective, double-blinded study to compare the clinical effect of 0.375% levobupivacaine with 0.5% levobupivacaine for ultrasound (US)-guided ABPB with nerve stimulation. METHODS: FORTY PATIENTS UNDERGOING ELECTIVE UPPER LIMB SURGERY WERE RANDOMIZED INTO TWO GROUPS: Group I (0.375% levobupivacaine) and Group II (0.5% levobupivacaine). All four main terminal nerves of the brachial plexus were blocked separately with 7 ml of levobupivacaine using US guidance with nerve stimulation according to study group. A blinded observer recorded the onset time for sensory and motor block, elapsed time to be ready for surgery, recovery time for sensory and motor block, quality of anesthesia, patient satisfaction and complications. RESULTS: There were no significant differences in the time to find nerve locations, time to perform block and number of skin punctures between groups. Insufficient block was reported in one patient of Group I, but no failed block was reported in either group. There were no differences in the onset time for sensory and motor block, elapsed time to be ready for surgery, patient satisfaction and complications. CONCLUSIONS: 0.375% levobupivacaine produced adequate anesthesia for ABPB using US guidance with nerve stimulation, without any clinically significant differences compared to 0.5% levobupivacaine.

The effects of hip abduction with external rotation and reverse Trendelenburg position on the size of the femoral vein; ultrasonographic investigation.

BACKGROUND: Femoral vein (FV) catheterization is required for critically ill patients, patients with difficult peripheral intravenous access, and patients undergoing major surgery. The purpose of this study was to evaluate the effects of hip abduction with external rotation (frog-leg position), and the frog-leg position during the reverse Trendelenburg position on diameter, cross-sectional area (CSA), exposed width and ratio of the FV using ultrasound investigation. METHODS: Ultrasonographic FV images of 50 adult subjects were obtained: 1) in the neutral position (N position); 2) in the frog-leg position (F position); 3) in the F position during the reverse Trendelenburg position (FRT position). Diameter, CSA, and exposed width of the FV were measured. Exposed ratio of the FV was calculated. RESULTS: The F and FRT positions increased diameter, CSA and exposed width of the FV significantly compared with the N position. However, the F and FRT positions had no significant effect on exposed ratio of the FV compared with the N position. The FRT position was more effective than the F position in increasing FV size. CONCLUSIONS: The F and FRT positions can be used to increase FV size during catheterization. These positions may increase success rate and reduce complication rate and, therefore, can be useful for patients with difficult central venous access or at high-risk of catheter-related complication.

Impending compartment syndrome of the forearm and hand after a pressurized infusion in a patient under general anesthesia -A case report-.

A 74-year-old woman underwent posterior lumbar decompressive fusion at L4-5 for treating spondylolisthesis, with the patient under general anesthesia and she was in the prone position. Following attempts to transfuse blood using a pressurized bag, the intravenous infusion site of the left hand along with the noninvasive blood pressure cuff was changed. Swelling and several bullae on the left forearm and hand were visible. Removal of intravenous catheter, hyaluronidase injection, wet dressing were subsequently performed. In postanesthesia recovery unit, the patient did not complain of pain, and the radial pulse and oxygen saturation of the left appeared normal. Three days after the incident, the edema on the patient's forearm and hand subsided, and the patient was discharged without any complications two weeks afterwards. Impending compartment syndrome should be given close attention, and particularly when performing pressurized infusion in patients who are unable to express pain because they are under general anesthesia.

Effect of stellate ganglion block on the cerebrovascular system: magnetic resonance angiography study.

BACKGROUND: Several studies have shown that stellate ganglion block (SGB) is an effective treatment for certain cerebrovascular related diseases; however, the direct effect of SGB on the cerebral vasculature is still unknown. The present study investigated the effect of SGB on the cerebral vascular system using magnetic resonance angiography. METHODS: Time-of-flight magnetic resonance angiography images of 19 healthy female volunteers (mean ages of 46.4 ± 8.9 yr) were obtained before and after SGB with 1.5-T magnetic resonance imaging. The authors determined successful interruption of sympathetic innervation to the head with the appearance of Horner syndrome and conjunctival injection. We measured changes in the average signal intensity and diameter of the major intracranial and extracranial arteries and their branches, which were presented with mean (±SE). RESULTS: The signal intensity changes were observed mainly in the ipsilateral extracranial vessels; the external carotid artery (11.2%, P < 0.001) and its downstream branches, such as the occipital artery (9.5%, P < 0.001) and superficial temporal artery (14.1%, P < 0.001). In contrast, the intensities of the intracranial arteries did not change with the exception of the ipsilateral ophthalmic artery, which increased significantly (10.0%, P = 0.008). After SGB, only the diameter of the ipsilateral external carotid artery was significantly increased (26.5%, P < 0.001). CONCLUSIONS: We were able to observe significant changes in the extracranial vessels, whereas the intracranial vessels were relatively unaffected (except for the ophthalmic artery), demonstrating that both perivascular nerve control and sympathetic nerve control mechanisms may contribute to the control of intracranial and extracranial blood vessels, respectively, after SGB.

The changes of heart rate variability after unilateral stellate ganglion block.

BACKGROUND: The effect of the unilateral stellate ganglion block (SGB) on cardiovascular regulation remains controversial. We wished to evaluate the changes in heart rate variability (HRV) after a unilateral stellate ganglion block in patients with head and neck pain in the present study. METHODS: Patients with head and neck pain (n = 89) were studied. HRV was determined before and after a C6 unilateral stellate ganglion block (right-sided SGB, 40; left-sided SGB, 49) using a paratracheal technique with 1% mepivacaine (6 ml). RESULTS: There were no significant differences in HRV indices before and after right-sided SGB. The log scale of power in the high frequency range (lnHF) was increased and ratio of power in the low frequency range (LF) to power in the high frequency range (HF) ratio was decreased after left-sided SGB. CONCLUSIONS: These results demonstrated that left-sided SGB increased parasympathetic activities in patients with head and neck pain.