Awake fiberoptic intubation in patients with stenosis of the upper airways: Utility of the laryngeal nerve block.

Awake fiberoptic intubation (AFOI) is mandatory to manage difficult airways. Superior laryngeal nerve block (SLNB) could reduce risks and improve patient comfort. The aim of this study is to assess the procedural comfort of SLNB during AFOI in a population of patients undergoing upper airway oncological surgery. Forty patients were randomized into two groups and were treated with continuous infusion of remifentanil, topic anesthesia and intercricoid block. In the study group (=20), SLNB was performed with lidocaine (L-SLNB); in the control group (n=20) SLNB was performed using saline (S-SLNB). AFOI was more comfortable in the L-SLNB group compared to S-SLNB patients [FOICS ≤ 1 in 18 patients (90%) L-SLNB; 2 (10%) S-SLNB (P <0.001)]. Intubation was faster in L-SLNB (47.45 ±15.38 sec) than S-SLNB (80.15 ±37.91 sec) (p <0.001). The SLNB procedure during AFOI is a safe and comfortable procedure in a population of patients undergoing upper airways surgery. Time to intubation was shorter in L-SLNB than in S-SLNB.

The Application of a Nanomaterial Optical Fiber Biosensor Assay for Identification of Brucella Nomenspecies.

Bacteria in the genus Brucella are the cause of brucellosis in humans and many domestic and wild animals. A rapid and culture-free detection assay to detect Brucella in clinical samples would be highly valuable. Nanomaterial optical fiber biosensors (NOFS) are capable of recognizing DNA hybridization events or other analyte interactions with high specificity and sensitivity. Therefore, a NOFS assay was developed to detect Brucella DNA from cultures and in tissue samples from infected mice. An ionic self-assembled multilayer (ISAM) film was coupled to a long-period grating optical fiber, and a nucleotide probe complementary to the Brucella IS711 region and modified with biotin was bound to the ISAM by covalent conjugation. When the ISAM/probe duplex was exposed to lysate containing ≥100 killed cells of Brucella, or liver or spleen tissue extracts from Brucella-infected mice, substantial attenuation of light transmission occurred, whereas exposure of the complexed fiber to non-Brucella gram-negative bacteria or control tissue samples resulted in negligible attenuation of light transmission. Oligonucleotide probes specific for B. abortus, B. melitensis, and B. suis could also be used to detect and differentiate these three nomenspecies. In summary, the NOFS biosensor assay detected three nomenspecies of Brucella without the use of polymerase chain reaction within 30 min and could specifically detect low numbers of this bacterium in clinical samples.

Near infrared photoimmunotherapy using a fiber optic diffuser for treating peritoneal gastric cancer dissemination.

BACKGROUND: Peritoneal dissemination (PD) of abdominal malignancies is a common form of metastasis and its presence signals a poor prognosis. New treatment is required for patients with PD. Near infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photo-absorber conjugate (APC). In this study, we investigate in vitro and in vivo efficacy of trastuzumab (tra)-IR700DX NIR-PIT on a human epidermal growth factor receptor type 2 (HER2)-positive gastric cancer cell line. METHODS: NIR-PIT effects were investigated in vitro and in vivo. Disseminated peritoneal implants mice were separated into 5 groups: (1) no treatment; (2) tra-IR700 i.v. only; (3) NIR light only; (4) NIR-PIT; (5) repeated NIR-PIT. The peritoneal cavity was irradiated with NIR light using a fiber optic diffuser delivered through the catheter. RESULTS: Specific binding and cell-specific killing was observed after NIR-PIT in vitro. In the in vivo study, fluorescence endoscopy showed high tumor accumulation of tra-IR700 within tumors. Significantly prolonged survival was achieved in the three treatment groups (tra-IR700 i.v. only, NIR-PIT, and repeated NIR-PIT groups) compared with control and NIR light only group (p < 0.05 for tra-IR700 i.v. only, p < 0.01 for NIR-PIT, and p < 0.0001 for repeated NIR-PIT). Moreover, most prolonged survival was shown for the repeated NIR-PIT group (p < 0.0001 vs tra-IR700 i.v. only, p < 0.01 vs NIR-PIT). CONCLUSION: NIR-PIT using a fiber optic diffuser to deliver light is a promising candidate for the treatment of disseminated peritoneal metastases and could be readily translated to humans.

Endoscopic near infrared photoimmunotherapy using a fiber optic diffuser for peritoneal dissemination of gastric cancer.

Near infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photo-absorber conjugate (APC) which is activated by near infrared light. Here, we describe the efficacy of endoscopic NIR-PIT using the APC trastuzumab-IR700DX (tra-IR700) in the setting of human epidermal growth factor 2 positive (HER2 + ) gastric carcinoma with peritoneal disseminations. In this in vivo study, fluorescence endoscopy showed high tumor accumulation of tra-IR700 within disseminated peritoneal implants. Mice with disseminated peritoneal gastric cancer were separated into 4 groups: (i) control (no treatment); (ii) tra-IR700 i.v. only; (iii) NIR light only; and (iv) endoscopic NIR-PIT. NIR light irradiation was carried out through a fiber optic diffuser under endoscopic guidance. In vivo bioluminescence images showed significantly greater therapeutic effect in the endoscopic NIR-PIT group than that in the control groups (P < .01 vs other control groups). Histological analysis showed diffuse cancer cell death in NIR-PIT-treated tumors. In conclusion, NIR-PIT with NIR light delivered via an endoscopic fiber optic diffuser is a promising method for the treatment of peritoneal dissemination of gastric cancer. Moreover, this technique could be readily used in other types of cancers with peritoneal dissemination provided that suitable antibodies could be found.

Awake Fiberoptic Intubation in Cervical Spine Injury: A Comparison between Atomized Local Anesthesia versus Airway Nerve Blocks.

Background In cooperative patients with cervical spine injury, awake fiberoptic intubation is an excellent option for elective and semi urgent situations. It allows documentation of neurologic examination before and after intubation and surgical positioning. We have compared anesthesia of airway by nerve block and the local anesthesia atomizer undergoing awake fiberoptic intubation in cervical spine injury patients, in terms of the intubation time and discomfort. Objective To compare the intubation time and discomfort in patient with cervical spine injury with anticipated difficult airway potential to aggravate pre-existing injury undergoing awake fiberoptic intubation, based on cough and gag scores, between anesthesia of airway by (transtracheal and bilateral superior laryngeal) nerve block with local anesthetic agent and the local anesthesia atomizer. Method After institutional ethical approval and having informed written consent, 30 patients scheduled for elective surgery who require awake fiberoptic intubation, were included in the study. Patients were allotted by computer-generated random series into two groups; Group N received nerve block (transtracheal and bilateral recurrent laryngeal nerve block) and Group A received atomized lignocaine. Result The time taken for awake fiberoptic intubation was significantly lower in nerve blocks group as compared with the atomizer group [Group N: 90.2±11.7secs and Group A: 210.4±10.6 secs (p=0.041)]. Atomizer group had an increased coughing and gagging episodes than nerve block group [Group N: one patient, Group A: 11 patients (p=0.006)]. Ease of intubation and patient comfort were significantly better in nerve block group. Demographic and hemodynamic parameters were comparable in the two groups. Conclusion The nerve blocks (bilateral superior laryngeal and transtracheal recurrent laryngeal) provides adequate airway anesthesia, lesser patient discomfort, and faster intubation to aid in awake fiberoptic intubation in patients with anticipated difficult airway as compared to topical anesthesia using atomizer.

Real-time, in-situ analysis of silver ions using nucleic acid probes modified silica microfiber interferometry.

A sensitive Ag+ sensor based on nucleic acid probes modified silica microfiber interferometry is designed and developed. The probes on microfiber surface plays the part on catching Ag+ as tentacles, while their conformation change from random coils to hairpins. It induces the fiber surface refractive index change, which is captured by the optical fiber and translated into a significant wavelength shift in the interferometric fringe. Such a combination enables an improved concentration sensitivity of 0.22nm/log M and limit of detection of 1.36 × 10-9M, taking the advantage of real-time and in-situ analysis. It shows good selectivity in the present of many other metal ions and offers potential to analysis in real matrix, especially in the environmental samples must be analyzed in a short time. This may provide insights into the preparation of sensing platforms for optical quantification of other small molecular, supplementing the existing tools.

Optical sensor based on hybrid FBG/titanium dioxide coated LPFG for monitoring organic solvents in edible oils.

A hybrid optical sensing scheme based on a fiber Bragg grating (FBG) combined with a titanium dioxide coated long period fiber grating (LPFG) for monitoring organic solvents in high refractive index edible oils is reported. In order to investigate and optimize the sensor performance, two different FBG/LPFG interrogation systems were investigated. The readout of the sensor was implemented using either the wavelength shift of the LPFG resonance dip or the variation in the optical power level of the reflected/transmitted light at the FBG wavelength peak, which in turn depends on the wavelength position of the LPFG resonance. Hexane concentrations up to 20%V/V, corresponding to the refractive index range from 1.451 to 1.467, were considered. For the transmission mode of operation, sensitivities of 1.41 nm/%V/V and 0.11 dB/%V/V, with resolutions of 0.58%V/V and 0.29%V/V, were achieved when using the LPFG wavelength shift and the FBG transmitted optical power, respectively. For the FBG reflection mode of operation, a sensitivity of 0.07 dB/%V/V and a resolution better than 0.16%V/V were estimated.

Comparison of Enk Fibreoptic Atomizer with translaryngeal injection for topical anaesthesia for awake fibreoptic intubation in patients at risk of secondary cervical injury: A randomised controlled trial.

BACKGROUND: Two methods of topical anaesthesia for awake fibreoptic intubation (FOI) in patients at risk of secondary cervical injury were compared: the translaryngeal injection (TLI) technique and the Enk Fibreoptic Atomizer. OBJECTIVE: The objective of this study was to determine which system of topical anaesthesia provides the fastest and most comfortable awake FOI, using the oral approach. DESIGN: A randomised controlled study. SETTING: A single centre trial between 2009 and 2011. PATIENTS: One hundred and twenty patients (63 women, 57 men) who underwent neurosurgery of the spine at Klinikum St. Georg Leipzig were randomly allocated into two groups (group TLI, 61 patients; group ENK-ATOMIZER, 59 patients). Inclusion criteria were an American Society of Anesthesiology (ASA) physical status of 1 to 3, age 18 to 80 years, and those who met any one of three indications for FOI - cervical instability, predicted difficult airway, a BMI greater than 40 kg m(-2), and who gave written informed consent.Exclusion criteria were emergency awake FOI, mental disability/delirium, polytrauma and contraindication to TLI. INTERVENTIONS: Two anaesthesiologists experienced in both techniques performed all anaesthesia procedures within the study. MAIN OUTCOME MEASURES: The primary outcome was the timing sequence of awake FOI. The incidence of coughing/gagging, ease of tracheal tube placement, mucosal bleeding, cardiopulmonary stability and postoperative outcomes were also investigated. RESULTS: Awake FOI was significantly faster using the TLI technique (mean, 191 s; range, 123 to 447 s; SD, 83.5) than the Enk Fibreoptic Atomizer [mean, 430 s; range, 275 to 773 s; SD, 124.9; (P = 0.0001)]. Patients in group TLI exhibited significantly less gagging (P = 0.047) but more mucosal bleeding (P <  .001). CONCLUSION: Awake FOI using the TLI technique was faster and provided better topical anaesthesia with less gagging during endoscopic intubation. However, the TLI technique was also more invasive. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00948350.

Fibreoptic vs videolaryngoscopic (C-MAC(®) D-BLADE) nasal awake intubation under local anaesthesia.

Numerous indirect laryngoscopes have been introduced into clinical practice and their use for tracheal intubation under local anaesthesia has been described. However, a study comparing indirect laryngoscopic vs fibreoptic intubation under local anaesthesia and sedation appears lacking. Therefore, we evaluated both techniques in 100 patients with an anticipated difficult nasal intubation time for intubation the primary outcome. We also assessed success rate, glottic view, Ramsey score, and patients' and anaesthetists' satisfaction. The median (IQR [range]) time for intubation was significantly shorter with the videolaryngoscope with 38 (24-65 [11-420]) s vs 94 (48-323 [19-1020]) s (p < 0.0001). There was no difference in the success rate of intubation (96% for both techniques; p > 0.9999) and satisfaction of the anaesthetists and patients. We conclude that in anticipated difficult nasal intubation a videolaryngoscope represents an acceptable alternative to fibreoptic intubation.

Awake intubation and awake prone positioning of a morbidly obese patient for lumbar spine surgery.

We describe the awake fibreoptic intubation followed by awake prone positioning of a woman weighing 180 kg with body mass index of 62 kg.m(-2) requiring emergency lumbar discectomy for cauda equina syndrome. This approach was taken to overcome difficulties in transfering an anaesthetised patient on to the operating table. Following topical anaesthesia with lidocaine and low-dose remifentanil infusion, oral intubation was performed using a split oral airway to guide the fibrescope. The patient positioned herself on the Jackson operating table, following which general anaesthesia was induced. This technique optimised protection of the patient's eyes and other pressure areas while preventing undue cardiorespiratory compromise. The patient tolerated the procedure well, and later confirmed that she would consent to undergoing the same procedure again if further surgery became necessary.

Indirect spectrophotometric determination of ultra trace amounts of selenium based on dispersive liquid-liquid microextraction-solidified floating organic drop.

A novel dispersive liquid-liquid microextraction-solidified floating organic drop (DLLME-SFOD) method combined with fiber optic-linear array detection spectrophotometry has been developed for the indirect determination of selenium. The method is based on the oxidation of the I(-) to iodine by inorganic Se(IV). The produced I2 reacts with the excess of I(-) ions in acidic media to give triiodide ions. The I3(-) is then extracted into 1-undecanol by DLLME-SFOD upon the formation of an ion pair with cetyltrimethylammonium cation. The extracted ion pair is determined by measuring its absorption at 360 nm. The absorbance signal is proportional to the selenium concentration in the aqueous phase. Under optimum conditions, the method provided an enrichment factor of 250 with a detection limit of 16.0 µg L(-1) and a linear dynamic range of 40.0-1000.0 µg L(-1). The relative standard deviation was found to be 2.1% (n=7) at 100.0 µg L(-1) concentration level. The method was successfully applied to th e determination of selenium in water samples and selenium plus tablet.

Wavelength-tunable picosecond soliton fiber laser with Topological Insulator: Bi2Se3 as a mode locker.

Based on the open-aperture Z-scan measurement, we firstly uncovered the saturable absorption property of the topological insulator (TI): Bi2Se3. A high absolute modulation depth up to 98% and a saturation intensity of 0.49 GWcm(-2) were identified. By incorporating this novel saturable absorber material into an erbium-doped fiber laser, wavelength tunable soliton operation was experimentally demonstrated. Our result indicates that like the atomic layer graphene, the topological insulator Bi2Se3 could also operate as an effective saturable absorber for the passive mode locking of lasers at the telecommunication band.

Experimental realization of a high-contrast grating based broadband quarter-wave plate.

Fabrication and experimental characterization of a broadband quarter-wave plate, which is based on two-dimensional and binary silicon high-contrast gratings, are reported. The quarter-wave plate feature is achieved by the utilization of a regime, in which the proposed grating structure exhibits nearly total and approximately equal transmission of transverse electric and transverse magnetic waves with a phase difference of approximately π/2. The numerical and experimental results suggest a percent bandwidth of 42% and 33%, respectively, if the operation regime is defined as the range for which the conversion efficiency is higher than 0.9. A compact circular polarizer can be implemented by combining the grating with a linear polarizer.

Evoked axonal oxytocin release in the central amygdala attenuates fear response.

The hypothalamic neuropeptide oxytocin (OT), which controls childbirth and lactation, receives increasing attention for its effects on social behaviors, but how it reaches central brain regions is still unclear. Here we gained by recombinant viruses selective genetic access to hypothalamic OT neurons to study their connectivity and control their activity by optogenetic means. We found axons of hypothalamic OT neurons in the majority of forebrain regions, including the central amygdala (CeA), a structure critically involved in OT-mediated fear suppression. In vitro, exposure to blue light of channelrhodopsin-2-expressing OT axons activated a local GABAergic circuit that inhibited neurons in the output region of the CeA. Remarkably, in vivo, local blue-light-induced endogenous OT release robustly decreased freezing responses in fear-conditioned rats. Our results thus show widespread central projections of hypothalamic OT neurons and demonstrate that OT release from local axonal endings can specifically control region-associated behaviors.

Continuous-wave laser stimulation of the rat prostate cavernous nerves using a compact and inexpensive all single mode optical fiber system.

BACKGROUND AND PURPOSE: Laser stimulation of the rat cavernous nerve (CN) recently has been demonstrated as an alternative to electrical stimulation for potential application in nerve mapping during nerve-sparing radical prostatectomy. Advantages include noncontact stimulation and improved spatial selectivity. Previous studies, however, have used large and/or expensive laser sources for stimulation. This study demonstrates the feasibility of optical stimulation of the rat CN, in vivo, using a compact, inexpensive all-single-mode fiberoptic system. MATERIALS AND METHODS: A 1455-nm wavelength infrared diode laser beam was coupled into a 9-µm-core single-mode fiber for delivery through a 10F laparoscopic probe and used for laser stimulation of the CN in a total of eight rats, in vivo. RESULTS: Laser stimulation of the CN was observed at threshold temperatures of 41°C, with intracavernous pressure response times as short as 4 s, and magnitudes up to 50 mm Hg, compared with baselines of 10 mm Hg. CONCLUSION: This novel, all-single-mode-fiber laser nerve stimulation system introduces several advantages including: (1) lower cost laser; (2) more robust fiberoptic design, eliminating alignment and cleaning of bulk optical components; and (3) improved Gaussian spatial beam profile for simplified alignment of the laser beam with the nerve. With further development, laser nerve stimulation may be useful for identification and preservation of the CN during prostate cancer surgery.

Antral lavage using the Luma transilluminaton wire and vortex irrigator--a safe and effective advance in treating pediatric sinusitis.

INTRODUCTION: While the treatment of pediatric sinusitis can be controversial, there is evidence that performing antral lavage in combination with adenoidectomy can improve treatment outcomes. We present an "over the wire" technique using new technology that can improve accuracy and reliability when performing antral lavage. METHODS: The LUMA fiberoptic light wire (Acclarent Inc.) and Vortex sinus irrigation catheter (Acclarent Inc.) were used to perform antral lavage as an adjunct in the treatment of pediatric sinusitis. DISCUSSION: We found this method to have multiple advantages over other techniques of lavage. These advantages include: 1) confirmation of position in the maxillary sinus by transillumination, 2) improvement of the safety and accuracy of the lavage, 3) ability to balloon dilate the natural ostium and ethmoid infundibulum or to obtain cultures at the time of lavage if clinically warranted or indicated by CT evidence, 4) avoidance of radiation from the use of fluoroscopy associated with other balloon sinuplasty equipment and techniques, and 5) no alteration of normal anatomy. CONCLUSION: We found this technique to give the surgeon a reliable, safe, versatile, and efficacious alternative before consideration of more invasive procedures in the pediatric population with chronic sinusitis.

Reduced Fresnel losses in chalcogenide fibers obtained through fiber-end microstructuring.

We demonstrate microstructuring of chalcogenide fiber facets in order to obtain enhanced transmission due to the antireflective properties of the microstructured surfaces. A variety of molding approaches have been investigated for As(2)S(3) and As(3)Se(3) fibers. Transmission as high as 97% per facet was obtained in the case of As(2)S(3) fiber, compared to the native, Fresnel-loss limited, transmission of 83%.

Atomised lidocaine for airway topical anaesthesia in the morbidly obese: 1% compared with 2%.

Airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in morbidly obese patients was evaluated using two doses of local anaesthetic. In this randomised, blinded prospective study, 40 ml of atomised 1% (n = 11) or 2% (n = 10) lidocaine was administered with high oxygen flow as carrier. Outcomes included time for intubation, patient tolerance to airway manipulation, haemodynamic parameters, the bronchoscopist's overall satisfaction, and serial serum lidocaine concentrations. Patients receiving lidocaine 1% had a longer mean (SD) time from the start of topicalisation to tracheal tube cuff inflation than those receiving lidocaine 2% (8.6 (0.9) min vs 6.9 (0.5) min, respectively; p < 0.05). Patients in the 1% cohort demonstrated increased responses to airway manipulation (p < 0.0001), reflecting lower bronchoscopist's satisfaction scores (p < 0.03). Haemodynamic responses to topicalisation and airway manipulation were similar in both groups. Peak plasma concentration was lower in the 1% group (mean (SD) 1.4 (0.3) and 3.8 (0.5) microg.ml(-1), respectively; p < 0.001). Airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in the morbidly obese is efficacious, rapid and safe. Compared with lidocaine 1%, the 2% dose provides superior intubating conditions.

Accuracy of real time noninvasive temperature measurements using magnetic resonance thermal imaging in patients treated for high grade extremity soft tissue sarcomas.

PURPOSE: To establish accuracy of real time noninvasive temperature measurements using magnetic resonance thermal imaging in patients treated for high grade extremity soft tissue sarcomas. METHODS: Protocol patients with advanced extremity sarcomas were treated with external beam radiation therapy and hyperthermia. Invasive temperature measures were compared to noninvasive magnetic resonance thermal imaging (MRTI) at 1.5 T performed during hyperthermia. Volumetric temperature rise images were obtained using the proton resonance frequency shift (PRFS) technique during heating in a 140 MHz miniannular phased array applicator. MRTI temperature changes were compared to invasive measurements of temperature with a multisensor fiber optic probe inside a #15 g catheter in the tumor. Since the PRFS technique is sensitive to drifts in the primary imaging magnetic field, temperature change distributions were corrected automatically during treatment using temperature-stable reference materials to characterize field changes in 3D. The authors analyzed MRT images and compared, in evaluable treatments, MR-derived temperatures to invasive temperatures measured in extremity sarcomas. Small regions of interest (ROIs) were specified near each invasive sensor identified on MR images. Temperature changes in the interstitial sensors were compared to the corresponding ROI PRFS-based temperature changes over the entire treatment and over the steady-state period. Nonevaluable treatments (motion/imaging artifacts, noncorrectable drifts) were not included in the analysis. RESULTS: The mean difference between MRTI and interstitial probe measurements was 0.91 degrees C for the entire heating time and 0.85 degrees C for the time at steady state. These values were obtained from both tumor and normal tissue ROIs. When the analysis is done on just the tumor ROIs, the mean difference for the whole power on time was 0.74 degrees C and during the period of steady state was 0.62 degrees C. CONCLUSIONS: The data show that for evaluable treatments, excellent correlation (deltaT < 1 degrees C) of MRTI-ROI and invasive measurements can be achieved, but that motion and other artifacts are still serious challenges that must be overcome in future work.