Positive end-expiratory pressure during one-lung ventilation for preventing atelectasis after video-assisted thoracoscopic surgery: a triple-arm, randomized controlled trial

BACKGROUND

There is little evidence regarding the benefits of lung-protective ventilation in patients undergoing one-lung ventilation for thoracic surgery. This study aimed to determine the optimal level of positive end-expiratory pressure (PEEP) during one-lung ventilation for minimizing postoperative atelectasis through lung ultrasonography.

METHODS

A total of 142 adult patients scheduled for video-assisted thoracoscopic surgery at Seoul National University Hospital between May 2019 and February 2020 were enrolled in this study. Patients were randomly assigned to different groups: 1) PEEP 3 cmH2O group; 2) PEEP 6 cmH2O group; and 3) PEEP 9 cmH2O group during one-lung ventilation. The lung ultrasound score was used to evaluate lung aeration using ultrasonography 1 hour after surgery.

RESULTS

The 1-hour post-surgery lung ultrasound scores were 8.1±2.5, 6.8±2.6, and 5.9±2.6 in the PEEP 3, 6, and 9 cmH2O groups, respectively (P<0.001). The PEEP 3 cmH2O group showed significantly higher lung ultrasound scores than the PEEP 6 (adjusted P=0.034) and 9 cmH2O groups (adjusted P<0.001). The PaO2/FiO2 ratio measured at 10 minutes after the end of one-lung ventilation was significantly lower in the PEEP 3 cmH2O group (392 [331 to 469]) than the PEEP 6 cmH2O (458 [384 to 530], adjusted P=0.018) or PEEP 9 cmH2O groups (454 [374 to 522], adjusted P=0.016).

CONCLUSIONS

Although the optimal level of PEEP during one-lung ventilation was not determined, the application of higher PEEP can prevent aeration loss in the ventilated lung after video-assisted thoracoscopic surgery under one-lung ventilation.

Videolaryngoscopy vs. flexible fibrescopy for tracheal intubation in patients with cervical spine immobilisation: a randomised controlled trial

In patients with cervical spine immobilisation, tracheal intubation devices other than a direct laryngoscope are frequently used to facilitate tracheal intubation and avoid related complications. In this randomised controlled trial, we compared videolaryngoscopic and fibrescopic tracheal intubation in patients with a cervical collar. Tracheal intubation was performed using either a videolaryngoscope with a non-channelled Macintosh blade (n = 166) or a flexible fibrescope (n = 164) in patients having elective cervical spine surgery whose neck was immobilised with a cervical collar to simulate a difficult airway. The primary outcome was the first attempt success rate of tracheal intubation. Secondary outcomes were the overall success rate of tracheal intubation; time to tracheal intubation; use of additional airway manoeuvres; and incidence and severity of tracheal intubation-related airway complications. First attempt success rate was higher in the videolaryngoscope group than in the fibrescope group (164/166 (98.8%) vs. 149/164 (90.9%), p = 0.003). Tracheal intubation was successful within three attempts in all patients. Median (IQR [range]) time to tracheal intubation was shorter (50.0 (41.0-72.0 [25.0-170.0]) s vs. 81.0 (65.0-107.0 [24.0-178.0]) s, p < 0.001) and additional airway manoeuvres were less frequent (30/166 (18.1%) vs. 91/164 (55.5%), p < 0.001) in the videolaryngoscope group compared with the fibrescope group. The incidence and severity of intubation-related airway complications were not different between the two groups. When performing tracheal intubation in patients with a cervical collar, videolaryngoscopy with a non-channelled Macintosh blade was superior to flexible fibrescopy.

Robotic single-site surgery in benign gynecologic diseases: Experiences and learning curve based on 626 robotic cases at a single institute

AIM

The purpose of this study was to report on 626 cases of successful robotic single-site (RSS) surgeries to address various types of gynecologic disease and to evaluate the outcomes and learning curve inherent to RSS surgery in the gynecology field.

METHODS

A total of 626 cases of RSS surgeries were performed by 3 gynecologic surgeons at Ewha Womans University Medical Center, Robot Surgery Center from November 2014 to January 2018 were collected retrospectively. All of the patients' charts were reviewed, and the clinical characteristics and surgical variables were analyzed.

RESULTS

Among the total of 626 cases, there were 220 cases of RSS myomectomy (RSSM), 182 cases of RSS hysterectomy (RSSH), 195 of RSS adnexectomy, 24 of RSS sacrocolpopexy (RSS SCP) and 5 were classified as other RSS surgeries. The patient's mean age was 38.98 ± 10.07 years. There was 3.99 ± 2.15 min of mean docking time and 117.78 ± 51.18 min of mean operating time. The surgical variables were analyzed annually. The total operating time was seen to decrease significantly according to each period. The docking time declined significantly and gradually after 1 year. We also analyzed each of the surgical types by time. The operating time of RSSH, RSSM, RSS adnexectomy and RSS SCP fell over time. The tendency found was for operating time to decline sharply following the first 10 cases. When we analyzed the data at annual intervals, the operating time was most significantly less and stable following the first year. There were a few intraoperative or perioperative complications in 16 cases (2.6%).

CONCLUSION

Robotic single-site surgery is a feasible and safe procedure for treating various kinds of gynecologic diseases. The learning curve was approximately 10 cases of RSS surgery in gynecologic disease, having a greater amount of experience at performing RSS surgery was revealed to be key to achieving better surgical outcomes.

Health-related quality of life in patients with a germline BRCA mutation and metastatic pancreatic cancer receiving maintenance olaparib

BACKGROUND

Patients with metastatic pancreatic cancer often have a detriment in health-related quality of life (HRQoL). In the randomized, double-blind, phase III POLO trial progression-free survival was significantly longer with maintenance olaparib, a poly(ADP-ribose) polymerase inhibitor, than placebo in patients with a germline BRCA1 and/or BRCA2 mutation (gBRCAm) and metastatic pancreatic cancer whose disease had not progressed during first-line platinum-based chemotherapy. The prespecified HRQoL evaluation is reported here.

PATIENTS AND METHODS

Patients were randomized to receive maintenance olaparib (300 mg b.i.d.; tablets) or placebo. HRQoL was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item module at baseline, every 4 weeks until disease progression, at discontinuation, and 30 days after last dose. Scores ranged from 0 to 100; a ≥10-point change or difference between arms was considered clinically meaningful. Adjusted mean change from baseline was analysed using a mixed model for repeated measures. Time to sustained clinically meaningful deterioration (TSCMD) was analysed using a log-rank test.

RESULTS

Of 154 randomized patients, 89 of 92 olaparib-arm and 58 of 62 placebo-arm patients were included in HRQoL analyses. The adjusted mean change in Global Health Status (GHS) score from baseline was <10 points in both arms and there was no significant between-group difference [-2.47; 95% confidence interval (CI) -7.27, 2.33; P = 0.31]. Analysis of physical functioning scores showed a significant between-group difference (-4.45 points; 95% CI -8.75, -0.16; P = 0.04). There was no difference in TSCMD for olaparib versus placebo for GHS [P = 0.25; hazard ratio (HR) 0.72; 95% CI 0.41, 1.27] or physical functioning (P = 0.32; HR 1.38; 95% CI 0.73, 2.63).

CONCLUSIONS

HRQoL was preserved with maintenance olaparib treatment with no clinically meaningful difference compared with placebo. These results support the observed efficacy benefit of maintenance olaparib in patients with a gBRCAm and metastatic pancreatic cancer.

CLINCALTRIALS.GOV NUMBER

NCT02184195.

Seven-year Follow-up of Resin Infiltration Treatment on Noncavitated Proximal Caries

The purpose of this case report is to present success and failure outcomes of seven-year follow-up of resin infiltration treatment (RIT) used for the proximal caries of maxillary premolars. Although resin infiltration can be a good option for micro-invasive treatment, long-term follow-up data are not sufficient, and the outcome of this technique can be affected by factors such as technique sensitivity of procedure, patient's caries risk, and depth of caries progression. Therefore, careful case selection, application, and follow-up are needed.

Forming mechanism of the bipolar resistance switching in double-layer memristive nanodevices

To initiate resistance switching phenomena, it is usually necessary to apply a strong electric field to a sample. This forming process poses very serious obstacles in real nanodevice applications. In unipolar resistance switching (URS), it is well known that the forming originates from soft dielectric breakdown. However, the forming in bipolar resistance switching (BRS) is poorly understood. In this study, we investigated the forming processes in Pt/Ta₂O₅/TaOx/Pt and Pt/TaOx/Pt nanodevices, which showed BRS and URS, respectively. By comparing the double- and single-layer systems, we were able to observe differences in the BRS and URS forming processes. Using computer simulations based on an 'interface-modified random circuit breaker network model', we could explain most of our experimental observations. This success suggests that the BRS forming in our Pt/Ta₂O₅/TaOx/Pt double-layer system can occur via two processes, i.e., polarity-dependent resistance switching in the Ta₂O₅ layer and soft dielectric breakdown in the TaOx layer. This forming mechanism can be used to improve the performance of BRS devices. For example, we could improve the endurance properties of Pt/Ta₂O₅/TaOx/Pt cells by using a small forming voltage.

Computerized assessment of cognitive impairment in narcoleptic patients

OBJECTIVES - This study was aimed to investigate the comprehensive range of cognitive performance using the objective computerized assessment system in narcolepsy and age, gender, and IQ-matched healthy comparison. MATERIALS AND METHODS - The cognitive functions of 24 patients with narcolepsy and 24 healthy comparison subjects were assessed. RESULTS - Narcoleptics performed more frequent omission and commission errors in the vigilance test, and more frequent omission errors in the continuous performance test. Narcoleptics' response time was slower than healthy volunteers, and the differences were more exaggerated in more complex tasks. The simple repetitious working performance was more impaired in the narcoleptic subjects than in healthy comparison subjects. Narcolepsy group showed worse performances in the determination unit than the comparison group, and this impairment became more salient in faster stimuli relative to slower ones. CONCLUSIONS - Narcoleptics have deficits of efficiency in attention allocation and execution as well as simple vigilance problem.

Loss of neurofilaments alters axonal growth dynamics

The highly regulated expression of neurofilament (NF) proteins during axon outgrowth suggests that NFs are important for axon development, but their contribution to axon growth is unclear. Previous experiments in Xenopus laevis embryos demonstrated that antibody-induced disruption of NFs stunts axonal growth but left unresolved how the loss of NFs affects the dynamics of axon growth. In the current study, dissociated cultures were made from the spinal cords of embryos injected at the two-cell stage with an antibody to the middle molecular mass NF protein (NF-M), and time-lapse videomicroscopy was used to study early neurite outgrowth in descendants of both the injected and uninjected blastomeres. The injected antibody altered the growth dynamics primarily in long neurites (>85 microm). These neurites were initiated just as early and terminated growth no sooner than did normal ones. Rather, they spent relatively smaller fractions of time actively extending than normal. When growth occurred, it did so at the same velocity. In very young neurites, which have NFs made exclusively of peripherin, NFs were unaffected, but in the shaft of older neurites, which have NFs that contain NF-M, NFs were disrupted. Thus growth was affected only after NFs were disrupted. In contrast, the distributions of alpha-tubulin and mitochondria were unaffected; thus organelles were still transported into neurites. However, mitochondrial staining was brighter in descendants of injected blastomeres, suggesting a greater demand for energy. Together, these results suggest a model in which intra-axonal NFs facilitate elongation of long axons by making it more efficient.

Two cases of atrial flutter with fetal hydrops: successful fetal drug therapy

We describe two cases of fetal atrial flutter associated with severe fetal hydrops which were unresponsive to digoxin but were successfully treated with flecainide acetate. Two cases of fetal atrial flutter were identified in fetuses with severe fetal hydrops on 3rd trimester ultrasonogram(28 weeks' gestation and 30 weeks' gestation). Following failed digoxin monotherapy, flecainide acetate was added to digoxin. On the 7th day and 13th day after combined therapy, fetal heart rate converted to normal sinus rhythm without recurrence. Our cases showed that the combined therapy of digoxin and flecainide acetate can effectively treat fetal atrial flutter associated with fetal hydrops unresponsive to digoxin monotherapy.

Neuromuscular interactions between mivacurium and esmolol in rabbits

We compared the dose-response relationship and the neuromuscular blocking effects of mivacurium during infusions of esmolol in 40 anaesthetised rabbits. Train-of-four stimuli were applied every 10 s to the common peroneal nerve and the force of contraction of the tibialis anterior muscle was measured. Plasma cholinesterase activity decreased by 13% after esmolol infusion. The ED95 of mivacurium increased significantly from 29 (4.8) micrograms.kg-1 with placebo to 61 (9.8) micrograms.kg-1 during esmolol 100 micrograms.kg-1.min-1, 49 (8.2) micrograms.kg-1 during esmolol 300 micrograms.kg-1.min-1 and 54 (7.3) micrograms.kg-1 during esmolol 500 micrograms.kg-1.min-1, respectively (p < 0.001). The duration of neuromuscular block with mivacurium 0.16 mg.kg-1 was prolonged by 30% with esmolol due to diminished plasma cholinesterase activity (p < 0.05). Heart rate and mean arterial blood pressure decreased by 15% with esmolol (p < 0.05). The results of this study show that, in rabbits, esmolol decreased plasma cholinesterase activity, antagonised the neuromuscular blocking potency of mivacurium and prolonged its neuromuscular blocking effect.