Airway leakage due to malpositioning of esophageal temperature probe during robot-assisted radical prostatectomy: a case report

Measuring patients' core body temperature during surgery is essential and commonly performed with an esophageal temperature probe. The probe must be placed in the lower third of the esophagus for accurate measurement. In this case report, we describe our experience of discovering an inadvertently malpositioned esophageal temperature probe in the right inferior lobar bronchus, which led to ventilation-related problems in a patient undergoing prostate surgery.

Differences in the predicted nasoseptal flap length among races: A propensity score matching analysis

OBJECTIVES

We compared the lengths of a nasoseptal flap (NSF) and skull base according to race, age, and sex.

METHODS

We performed paranasal sinus computed tomography in 19,961 adult patients between 2003 and 2022. The race of the patients was East Asian (n = 71), Caucasian (n = 71), or Middle Eastern (n = 71). The expected lengths of the NSF and anterior skull base defect were measured and analyzed according to race, age, and sex.

RESULTS

Compared with Caucasians and Middle Easterners, East Asians had a shorter NSF length (p < 0.001) and lower ratio of the expected NSF length to the expected defect length (p < 0.001). There was no difference in the values among age groups. The expected NSF length was longer, and the ratio of the expected NSF length to the expected defect length was higher, in males than females (p < 0.001 for both).

CONCLUSIONS

East Asians and females had a shorter NSF length and lower ratio of expected NSF to surgical defect lengths after anterior skull base reconstruction compared with the other races and with males, respectively. Anatomical differences should be considered when long NSF lengths are required, such as for anterior skull base reconstruction.

YouTube as an Information Resource for Persons Interested in Septoplasty and/or Turbinoplasty

Background and Objectives: YouTube is a widely used web site. In general, many people search for medical information on YouTube. We evaluated the septoplasty and turbinoplasty videos on YouTube from an expert’s point of view.Methods: We used “septoplasty,” “turbinoplasty,” and “septoplasty turbinoplasty” to search YouTube. Of the 150 videos, we eventually viewed 83. Two researchers assessed the sources, lengths, and numbers of likes, dislikes, and views. The videos were classified as “excellent,” “moderate,” or “poor” in terms of utility; we also evaluated the uploaded material and content.Results: Of the 83 videos, 18 (21.7%) were excellent, 27 (32.5%) were moderate, and 38 (45.8%) were poor. We found no significant differences in length and mean likes, dislikes, and views between the groups classified as useful. Fifteen (39.5%) of 38 poor videos were by patients, and 13 (34.2%) of 38 poor videos were by physicians. When organized by content type, videos on personal experiences were significantly longer than the others. Of 20 videos on personal experiences, 15 (75%) were poor and all 5 advertisement videos (100%) were poor.Conclusion: Information from YouTube on septoplasty and turbinoplasty is not yet adequate. However, since YouTube content cannot be controlled, it is necessary to upload objective and accurate videos for patients and experts in professional groups such as the medical society. Such videos should be promoted and used actively.

Unexpected pulmonary edema and cardiac arrest following wedge resection of spontaneous pneumothorax -A case report-

Background

Reexpansion pulmonary edema is a rare but potentially lethal complication. We report a case of suspected reexpansion pulmonary edema that led to cardiac arrest.

Case

A 16-year-old male patient underwent wedge resection due to right pneumothorax. The patient showed pink frothy sputum three hours following surgery, and a chest x-ray showed right unilateral pulmonary edema. Thirteen hours following surgery, the patient continuously showed pink frothy sputum and presented with severe hypoxemia, tachypnea, and tachycardia. After transferring to the intensive care unit (ICU), he developed ventricular tachycardia. Cardiopulmonary resuscitation was performed for 32 min. Chest X-ray showed diffuse bilateral pulmonary edema. Extracorporeal membrane oxygenation was performed. During the 65 days of ICU care, the patient became mentally alert. However, follow-up echocardiography revealed severe heart failure.

Conclusions

Rexpansion pulmonary edema can rapidly progress to diffuse bilateral pulmonary edema. Therefore, careful observation is required for the patients who show signs of pulmonary edema after reexpansion.

Adverse events of sugammadex that occurred in a Korean population

Background

With increasing use, the incidence of adverse events associated with sugammadex, a neuromuscular blockade reverser, is increasing. This study aimed to identify and analyze cases of adverse events caused by sugammadex reported in Korean population.

Methods

Out of a total of 12 cases detected using various keywords in the Korean Journal of Anesthesia, Anesthesia and Pain Medicine (Seoul), KoreaMed, PubMed, EMBASE, Web of Science, and The Cochrane Library-CENTRAL from 2013 to December 2020, 10 cases directly associated with sugammadex were selected.

Results

Adverse events included five cases of anaphylaxis, one case of cardiac arrest, one case of profound bradycardia, one case of negative pressure pulmonary edema, and two cases of incomplete recovery. Three patients had American Society of Anesthesiologists physical status ≥ 3, two had emergency surgery, and two had a history of allergic reaction. Neuromuscular monitoring was applied in nine cases. The average dose of sugammadex was 2.87 mg/kg, and there were six cases in which one full vial was used, regardless of the state of neuromuscular recovery. Sugammadex was administered immediately after surgery in two cases, at train of four (TOF) 0 in four cases, at TOF 3 in one case, and after evaluation of the clinical signs only with no neuromuscular monitoring in one case.

Conclusions

Even with neuromuscular monitoring, an excessive dose of sugammadex was observed. Given that adverse events tend to occur within 10 min of administration, continuous monitoring is important even after administration.

Changes in the Sphenoid Bone Encountered During the Endoscopic Endonasal Transsphenoidal Approach

OBJECTIVES

We estimated volume changes in the posterior bony wall of the sphenoid sinus, as well as alterations in nasal function (including olfactory function and subjective symptoms), after sphenoid mucosal repositioning using the endoscopic endonasal transsphenoidal approach (EETSA).

METHODS

During 2010 and 2021, 13 patients underwent sphenoid mucosal repositioning during EETSA, while 24 patients (the control group) did not. Pre- and postoperative paranasal sinus computed tomography and the Mimics program were used to evaluate three-dimensional changes in the posterior wall of the sphenoid sinus. All patients underwent the Connecticut Chemosensory Clinical Research Center (CCCRC) test, the Cross-Cultural Smell Identification Test (CCSIT), Nasal Obstruction Symptoms Evaluation (NOSE), the Sino-Nasal Outcome Test-20 (SNOT-20), and visual analog scale (VAS) evaluation.

RESULTS

The increase in the volume of the posterior wall of the sphenoid sinus after surgery was objectively smaller in the sphenoid mucosal repositioning group than in the control group (P = .046). However, this did not affect olfactory function (as revealed by the CCCRC test or the CCSIT) or subjective symptoms (as revealed by the NOSE, SNOT-20, and VAS scores) (all P > .05).

CONCLUSION

Surgical closure via sphenoid mucosal repositioning during EETSA reduces the volume of the posterior wall of the sphenoid sinus and facilitates re-operation. We suggest that sphenoid mucosal repositioning is appropriate during EETSA.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Comparative study of new autologous material, bone-cartilage composite graft, for ossiculoplasty with Polycel® and Titanium

OBJECTIVE

Ossiculoplasty is a surgical procedure that recreates sound transmission of the middle ear in conductive hearing loss. Various materials have been used for ossicular reconstruction, but the most ideal material for ossiculoplasty remains controversial. The purpose of this study was to introduce a novel method of autologous ossiculoplasty, bone-cartilage composite graft (BCCG) and to compare its surgical results with different types of ossiculoplastic prostheses.

STUDY DESIGN

A retrospective study was performed in a tertiary referral centre.

METHODS

Data of 275 patients who received ossiculoplasty using the three different materials of BCCG, Polycel^® and titanium were analysed according to type of ossiculoplasty: partial or total ossicular replacement prosthesis (PORP or TORP). Hearing results, complication rates and clinical parameters including age, sex, past history, preoperative diagnosis and surgery type were compared among different groups.

RESULTS

Ossiculoplasty with BCCG showed satisfactory hearing outcomes and the lowest complication rate among the three different materials. In particular, its extrusion rate was 0%.

CONCLUSION

We propose that the BCCG technique is a useful alternative method for ossiculoplasty, with proper patient selection.

Optical reflection modulation using surface plasmon resonance in a graphene-embedded hybrid plasmonic waveguide at an optical communication wavelength

We propose a high-performance, graphene-based optical modulator with a surface plasmon resonance (SPR) at 1550 nm. In the proposed device, a graphene layer is embedded in a hybrid plasmonic waveguide to enhance the light-graphene interaction. The adjustment of the permittivity of the graphene causes a significant modulation of the absorption in the SPR through a variation of the field confinement in the graphene layer, in addition to a resonant angle shift. With an optimal thickness of a metal (Ag) film and the properly chosen operation point of the Fermi level of graphene, a modulation depth of ∼100% was achieved. As the number of graphene layers in the proposed device increases, the insertion loss decreases. With five-layer graphene, a 6% insertion loss was achieved.

Slot-embedded photonic-crystal resonator with enhanced modal confinement

A photonic-crystal (PC) resonator has attracted a great deal of attention for the strong light-matter interaction. Many attempts have been made to achieve a high-quality factor of the PC resonator, but they always have accompanied increases of modal volumes. In this work, we propose a novel method to enhance modal confinement of the PC resonator without compromising the quality factor. In the proposed structure, a thin low-index slot layer is embedded in a two-dimensional PC for vertical confinement, which results in a remarkable mode volume reduction without a decrease of the quality factor. By optimizing the slot thickness, a quality factor to mode volume ratio, which is a figure of merit for an optical resonator, could be increased by 8 times.

Dominant mode control of a graphene-embedded hybrid plasmonic resonator for a tunable nanolaser

A graphene-embedded tunable plasmonic nanodisk resonator operating at near-infrared wavelength range is proposed, in which a certain resonant mode among multiple whispering-gallery modes (WGMs) can be selected as a dominant mode by modulating the Fermi level of the graphene. Our theoretical investigation reveals that the dominant mode selection mechanism in the proposed resonator is governed by the figure-of-merit (FOM) of the one-dimensional (1D) waveguide of the resonator's vertical structure, which is defined as a propagation length to mode size ratio. As the conductivity of the graphene changes with a gating voltage, the wavelength dependence of the FOM changes and a WGM closest to the maximum FOM wavelength is selected. Partial tuning of the selected dominant mode is incurred by the change of the effective index of the 1D waveguide. This novel mode selection mechanism of the proposed resonator can be adopted to realize an optically pumped tunable nanolaser with a wide wavelength tuning range.

Metal nanodisk hybrid plasmonic resonator on dielectric substrate for relieved fabrication complexity

We propose a metal nanodisk hybrid plasmonic resonator (HPR), which consists of a metallic nanodisk on top of a dielectric slab. In contrast to the previously studied plasmonic resonator structures based on metal substrates such as the nanopatch resonator, the fabrication process of the proposed resonator is much easier because of a dielectric substrate. The performance of the proposed resonator has been theoretically investigated and compared to the previously studied structures. It has been shown that the performance of the proposed resonator is superior to that of the nanopatch resonator and comparable to that of a hybrid resonator based on a metal substrate.

Circular hybrid plasmonic waveguide with ultra-long propagation distance

We propose a novel plasmonic waveguide structure, which is referred to as a circular hybrid plasmonic waveguide (HPW) and consists of a metal wire covered with low- and high-index dielectric layers. The circular HPW exhibits two distinctly different modes, namely, the strongly localized mode and the extremely low-loss mode. Our numerical calculation demonstrates that the strongly localized mode exhibits 10^-4 order scale in normalized mode area and can be performed even in tens of nanometer sizes of waveguide geometry. In the extremely low-loss mode, the HPW exhibits ultra-long propagation distance of more than 10³μm that can be achieved by forming the dipole-like hybrid mode and properly adjusting the radius of the metal wire. It is also shown that, even with this long-range propagation, the mode area of the dipole-like hybrid mode can be maintained at subwavelength scale. The simultaneous achievement of a small mode area and ultra-long propagation distance contributes to the ultra-high propagation distance to mode size ratio of the waveguide. The HPW results are very helpful for plasmonic device applications in the fields of low-threshold nanolasers, ultrafast modulators, and optical switches.

Antinociceptive effects and synergistic interaction with morphine of intrathecal metabotropic glutamate receptor 2/3 antagonist in the formalin test of rats

Spinal metabotropic glutamate receptors (mGluRs) have been known to be involved in the modulation of nociception. While the antinociceptive effects of the mGluR1/5 have been demonstrated, the role of mGluR2/3 for nociception is less clear. This study investigated the effects of an intrathecal mGluR2/3 agonist, APDC, and a mGluR2/3 antagonist, LY341495, for inflammatory and acute pain in the formalin test and thermal stimulation test. We also examined their interaction with intrathecal morphine for the antinociceptive effect. APDC had little effect on the formalin-induced nociception. In contrast, LY341495 caused a dose-dependent suppression of the phase 2 flinching response to the formalin stimulus without affecting phase 1 flinching response. Furthermore, the suppression of pain behavior by LY341495 during phase 2 was reduced significantly by pretreatment with APDC. LY341495 and morphine also showed synergistic drug interaction for antinociception during phase 2 in the formalin test.

Effects of intracoronary calcium chloride on regional oxygen balance and mechanical function in normal and stunned myocardium in dogs

BACKGROUND

Brief myocardial ischaemia has been demonstrated to result in mechanical and coronary endothelial dysfunction, in which calcium may play a role. We examined whether the mechanical and vascular responses to calcium are altered in postischaemic, reperfused myocardium.

METHODS

Regional myocardial oxygen consumption (MVO2), mechanical function and coronary blood flow (CBF) in response to calcium chloride (0.10, 0.25, 0.50 and 0.75 mg ml(-1) of CBF) directly infused into the left anterior descending (LAD) artery were determined before (normal) and 30 min after a 15-min-period of LAD occlusion (stunned) in an open-chest canine model. Percentage segment shortening (%SS) and percentage postsystolic shortening (%PSS) in the LAD territory were determined using ultrasonic crystals and CBF using a Doppler transducer. Myocardial extraction of oxygen (EO2) and lactate (Elac) was calculated.

RESULTS

The infusion of calcium chloride resulted in dose-dependent increases in %SS and MVO2 but did not affect %PSS in normal myocardium. These changes were accompanied by parallel increases in CBF, resulting in no change in EO2. In stunned myocardium, the responses to calcium chloride were not significantly altered, with the exception of a reduction in %PSS. However, ischaemia and reperfusion itself significantly reduced %SS and Elac and increased %PSS.

CONCLUSIONS

These data suggest that calcium chloride improves regional systolic and diastolic function both in normal and stunned myocardium. Calcium chloride is unlikely to cause direct coronary vasoconstriction or to deteriorate regional mechanical function in postischaemic myocardium.

New E. coli cloning vector using a cellulase gene (celA) as a screening marker

The extracellular endoglucanase A gene of Clostridium thermocellum (celA) was used as a screening marker for E. coli cloning vector A 1.4-kb EcoRI fragment containing celA from pTvec/celA was isolated and cloned into a pUC18 deleting beta-galactosidase gene fragment. The constructed vectors, pCEL1, pCEL10, pCEL11, and pCEL20, have different multiple cloning sites within celA. If the cellulase, CelA, is inactivated by insertion of a foreign DNA fragment into multiple cloning sites, the recombinant transformants show no clear halos on an agar plate containing cellulose. This process overcomes the ambiguity of color screening in the X-gal/beta-galactosidase system, and over 90% of the recombinant transformants with no halos have foreign DNA inserts. Several E. coli strains were transformed successfully with pCEL series vectors regardless of mutation for alpha-complementation. Because E. coli strains do not have a cellulase gene, a vector using a cellulase gene screening marker can be used in any E. coli strain without limit. The new cloning system is very efficient, convenient, and cost effective.

Synergistic effects between intrathecal clonidine and neostigmine in the formalin test

Spinal alpha-2 adrenoceptors and cholinergic receptors are involved in the regulation of acute nociception and the facilitated processing. The aim of this study was to examine the pharmacological effect of an intrathecal alpha-2 agonist and a cholinesterase inhibitor on the facilitated pain model induced by formalin injection and to determine the nature of drug interaction using an isobolographic analysis. Both intrathecal clonidine and neostigmine dose-dependently suppressed the flinching during phase 1 and phase 2. Intrathecal pretreatment with atropine reversed the antinociceptive effects of clonidine and neostigmine in both phases. Pretreatment with intrathecal yohimbine attenuated the effect of clonidine. The antinociception of clonidine and neostigmine was not reversed by mecamylamine. Isobolographic analysis showed that intrathecal clonidine and neostigmine acted synergistically in both phase 1 and 2. Intrathecal pretreatment with atropine and yohimbine antagonized the effect of the mixture of clonidine and neostigmine in both phases, but no antagonism was observed with mecamylamine pretreatment. These data indicate that spinal clonidine and neostigmine are effective to counteract the facilitated state evoked formalin stimulus, and these two drugs interact in a synergistic fashion. In addition, the analgesic action of intrathecal clonidine is mediated by spinal muscarinic receptors as well as alpha-2 adrenoceptors.

Intracoronary propofol attenuates myocardial but not coronary endothelial dysfunction after brief ischaemia and reperfusion in dogs

We have investigated the effects of propofol on recovery of regional mechanical and coronary endothelial function and on lipid peroxidation in post-ischaemic myocardium in dogs. The animals were assessed for 180 min during reperfusion after 15-min of occlusion of the left anterior descending coronary artery (LAD). They were treated with intracoronary (i.c.) propofol 5 or 20 micrograms/ml of coronary flow or vehicle (control group) for 60 min, beginning 30 min before LAD occlusion. Propofol significantly enhanced recovery of regional contractile function (70% and 81% of baseline segment shortening in the propofol 5 and 20 micrograms ml-1 groups, respectively, compared with 51% in controls at 3 h of reperfusion). However, LAD flow responses to i.c. acetylcholine were similarly attenuated regardless of treatment with propofol throughout reperfusion. The increase in malondialdehyde induced by ischaemia-reperfusion was significantly suppressed by both doses of propofol. These results demonstrated that in vivo, propofol ameliorated dysfunction of the myocardium but not of the coronary endothelium resulting from brief ischaemia and reperfusion; the protection may be related, at least in part, to its ability to reduce lipid peroxidation.