Does severe obstructive sleep apnea syndrome alter retrobulbar blood flow? A color Doppler ultrasound study

Purpose

To evaluate extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of severe obstructive sleep apnea (OSA) on retrobulbar blood flow.

Methods

Between February 2014 and September 2015, 30 patients with severe OSA (apnea–hypopnea index (AHI) > 30) and 28 controls were prospectively included in this study. Intraocular pressure (IOP) was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels.

Results

The mean AHI score for the OSA group was 63.2 ± 21.5 per hour. The IOP values were significantly higher in the severe OSA group (p < 0.05). The central retinal artery peak systolic velocity (PSV) (p < 0.05) and end-diastolic velocity (EDV) (p < 0.02), and the ophthalmic artery (OA) PSV and EDV, were found to be significantly lower in the OSA group (p < 0.05).

Conclusion

Severe OSA causes an increase in IOP and a decrease in flow velocity in the retrobulbar circulation.

     

Efficiency of quantitative echogenicity for investigating supraspinatus tendinopathy by the gray-level histogram of two ultrasound devices

Purpose

The gray-level histogram of ultrasound is a promising tool for scanning the hypoechogenic appearance of supraspinatus tendinopathy, and the aim of this study was to test the hypothesis that the gray-level value of the supraspinatus tendon in the painful shoulder has a lower value on B-mode images even though in different ultrasound devices.

Methods

Sixty-seven patients who had unilateral shoulder pain with rotator cuff tendinopathy underwent bilateral shoulder ultrasonography, and we compared the mean gray-level values of painful shoulders and contralateral shoulders without any pain in each patient using two ultrasound devices. The echogenicity ratio (symptomatic/asymptomatic side) of two ultrasound devices was compared.

Results

A significant difference existed between the symptomatic shoulder and contralateral asymptomatic shoulder (p < 0.001) on the mean gray-level value measurements of each device. The symptomatic-to-asymptomatic tendon echogenicity ratio of device A was 0.919 ± 0.090 in the transverse plane and 0.937 ± 0.081 in the longitudinal plane, and the echogenicity ratio of device B was 0.899 ± 0.113 in the transverse plane and 0.940 ± 0.113 in the longitudinal plane.

Conclusions

The decline of the mean gray-level value and the echogenicity ratio of the supraspinatus tendon in the painful shoulder may be utilized as a useful sonographic reference of unilateral rotator cuff lesions.

Level of evidence

Diagnostic level III.

     

Apoptotic and genotoxic effects of low-intensity ultrasound on healthy and leukemic human peripheral mononuclear blood cells

Purpose

To scrutinize the apoptotic and genotoxic effects of low-intensity ultrasound and an ultrasound contrast agent (SonoVue; Bracco Diagnostics Inc., EU) on human peripheral mononuclear blood cells (PMBCs).

Methods

PMBCs were subjected to a low-intensity ultrasound field (1-MHz frequency; spatial peak temporal average intensity 0.18 W/cm2) followed by analysis for apoptosis and DNA damage (single-strand breaks + double-strand breaks). The comet assay was then repeated after 2 h to examine the ability of cells to repair DNA breaks.

Results

The results demonstrated that low-intensity ultrasound was capable of selectively inducing apoptosis in leukemic PMBCs, but not in healthy cells. The introduction of ultrasound contrast agent SonoVue resulted in an increase in apoptosis in both groups. DNA analysis after ultrasound exposure indicated that ultrasound triggered DNA damage in leukemic PMBCs (66.05 ± 13.36%), while the damage was minimal (7.01 ± 0.89%) in control PMBCs. However, both cell lines demonstrated an ability to repair DNA single- and double-strand breaks 2 h after sonication.

Conclusions

The study demonstrated that low-intensity ultrasound selectively induced apoptosis in cancer PMBCs. Ultrasound-induced DNA damage was observed primarily in leukemic PMBCs. Nevertheless, both cell lines were able to repair ultrasound-mediated DNA strand breaks.

     

The effect of ultrasound with acoustic radiation force on rabbit lung tissue: a preliminary study

Purpose

Acoustic radiation force (ARF) elastography has recently become available. The previous animal studies have revealed lung injuries induced by diagnostic ultrasound, but the effects on the lung resulting from exposure to ultrasound with ARF are unknown. This study aimed to assess the risk of lung injury associated with ultrasound with ARF.

Methods

A focused 2.5-MHz transducer that emits ultrasound with ARF was used. A rabbit was anesthetized, and the transducer was placed in the right subcostal region. Exposure settings of mechanical index (MI) 0.80, pulse duration 10 ms, pulse repetition time 5 s, and exposure time 150 s were applied.

Results

One red spot (7 × 6 mm) was observed on the surface of the right lung corresponding to the area of exposure. Alveolar hemorrhage was observed microscopically. This lesion was visible across a range of 20–170 μm in depth from the pleural surface.

Conclusion

The first example of lung hemorrhage induced by ultrasound with ARF was observed in this study. This observation suggests the possibility of lung injury in humans when ARF elastography is applied with the transducer directed toward the lung. Further studies are needed to determine the safety of this modality.

     

Ultrasound thermal monitoring with an external ultrasound source for customized bipolar RF ablation shapes

Purpose

Thermotherapy is a clinical procedure which delivers thermal energy to a target, and it has been applied for various medical treatments. Temperature monitoring during thermotherapy is important to achieve precise and reproducible results. Medical ultrasound can be used for thermal monitoring and is an attractive medical imaging modality due to its advantages including non-ionizing radiation, cost-effectiveness and portability. We propose an ultrasound thermal monitoring method using a speed-of-sound tomographic approach coupled with a biophysical heat diffusion model.

Methods

We implement an ultrasound thermometry approach using an external ultrasound source. We reconstruct the speed-of-sound images using time-of-flight information from the external ultrasound source and convert the speed-of-sound information into temperature by using the a priori knowledge brought by a biophysical heat diffusion model.

Results

Customized treatment shapes can be created using switching channels of radio frequency bipolar needle electrodes. Simulations of various ablation lesion shapes in the temperature range of 21–59 \(^\circ \)C are performed to study the feasibility of the proposed method. We also evaluated our method with ex vivo porcine liver experiments, in which we generated temperature images between 22 and 45 \(^\circ \)C.

Conclusion

In this paper, we present a proof of concept showing the feasibility of our ultrasound thermal monitoring method. The proposed method could be applied to various thermotherapy procedures by only adding an ultrasound source.

     

Assessment of a new prototype hydrogel CO<Subscript><Emphasis Type="Bold">2</Emphasis></Subscript> sensor; comparison with air tonometry

Objective

Gastrointestinal ischemia is always accompanied by an increased luminal CO₂. Currently, air tonometry is used to measure luminal CO₂. To improve the response time a new sensor was developed, enabling continuous CO₂ measurement. It consists of a pH-sensitive hydrogel which swells and shrinks in response to luminal CO₂, which is measured by the pressure sensor. We evaluated the potential clinical value of the sensor during an in vitro and in vivo study.

Methods

The response time to immediate, and stepwise change in pCO₂ was determined between 5 and 15 kPa, as well as temperature sensitivity between 25 and 40 °C at two pCO₂ levels. Three sensors were compared to air tonometry (Tonocap^®) in healthy volunteers using a stepwise incremental exercise test, followed by a period of hyperventilation and an artificial CO₂-peak.

Results

The in vitro response time to CO₂ increase and decrease was mean 5.9 and 6.6 min. The bias, precision and reproducibility were +5%, 3% and 2%, resp. Increase of 1 °C at constant pCO₂ decreased sensor signal by 8%. In vivo tests: The relation with the Tonocap was poor during the exercise test. The response time of the sensor was 3 min during hyperventilation and the CO₂ peak.

Conclusion

The hydrogel carbon dioxide sensor enabled fast and accurate pCO₂ measurement in a controlled environment but is very temperature dependent. The current prototype hydrogel sensor is still too unstable for clinical use, and should therefore be improved.

     

Prediction of spontaneous vaginal delivery by transperineal ultrasound performed just after full cervical dilatation is determined

Purpose

To investigate whether transperineal ultrasound examination just after full cervical dilatation is determined can predict the mode of delivery.

Methods

This was a prospective observational study of pregnant women. After full cervical dilatation was determined by vaginal examination during labor, transperineal ultrasound was immediately performed, and the head direction (HD), progression distance (PD), and angle of progression (AoP) were measured. The cases were divided into two groups: spontaneous vaginal delivery and operative delivery due to failure of progression. Differences between the groups were statistically analyzed using Student’s t test and Fisher’s exact test.

Results

Of the 50 women, 42 had spontaneous vaginal deliveries and 8 had vacuum extractions. The spontaneous delivery group had significantly higher HD, PD, and AoP values than the vacuum extraction group. The areas under the receiver-operating characteristic curves for the prediction of spontaneous vaginal delivery were 0.850 for HD, 0.827 for PD, and 0.783 for AoP. The optimum cut-off points and positive predictive values were 83° and 92.9 % for HD, 56 mm and 94.9 % for PD, and 146° and 94.3 % for AoP, respectively.

Conclusion

Transperineal ultrasound examination just after full cervical dilatation was determined was useful in predicting spontaneous vaginal delivery.

     

Comparing position and orientation accuracy of different electromagnetic sensors for tracking during interventions

Purpose

To compare the position and orientation accuracy between using one 6-degree of freedom (DOF) electromagnetic (EM) sensor, or the position information of three 5DOF sensors within the scope of tumor tracking.

Methods

The position accuracy of Northern Digital Inc Aurora 5DOF and 6DOF sensors was determined for a table-top field generator (TTFG) up to a distance of 52 cm. For each sensor 716 positions were measured for 10 s at 15 Hz. Orientation accuracy was determined for each of the orthogonal axis at the TTFG distances of 17, 27, 37 and 47 cm. For the 6DOF sensors, orientation was determined for sensors in-line with the orientation axis, and perpendicular. 5DOF orientation accuracy was determined for a theoretical 4 cm tumor. An optical tracking system was used as reference.

Results

Position RMSE and jitter were comparable between the sensors and increasing with distance. Jitter was within 0.1 cm SD within 45 cm distance to the TTFG. Position RMSE was approximately 0.1 cm up to 32 cm distance, increasing to 0.4 cm at 52 cm distance. Orientation accuracy of the 6DOF sensor was within 1\(^\circ \), except when the sensor was in-line with the rotation axis perpendicular to the TTFG plane (4\(^\circ \) errors at 47 cm). Orientation accuracy using 5DOF positions was within 1\(^\circ \) up to 37 cm and 2\(^\circ \) at 47 cm.

Conclusions

The position and orientation accuracy of a 6DOF sensor was comparable with a sensor configuration consisting of three 5DOF sensors. To achieve tracking accuracy within 1 mm and 1\(^\circ \), the distance to the TTFG should be limited to approximately 30 cm.

     

Nasal continuous positive airway pressure decreases respiratory muscles overload in young infants with severe acute viral bronchiolitis

Objective

To determine the efficacy of nasal continuous positive airway pressure (nCPAP) on respiratory distress symptoms and respiratory effort in young infants with acute respiratory syncytial virus bronchiolitis.

Design

Prospective study.

Setting

The paediatric intensive care unit of a university hospital.

Patients

Twelve infants less than 3 months of age, with severe respiratory distress.

Interventions

Respiratory distress was quantified with a specific scoring system. Oesophageal pressure (Pes) was measured during spontaneous ventilation before and after nCPAP, delivered through an infant-adapted ventilator. Simultaneous recording of gastric pressure (Pgas) was performed in the five oldest patients.

Measurements and results

The respiratory distress score decreased after nCPAP, particularly accessory muscles’ use and expiratory wheezing. The breathing pattern was modified, with shorter inspiratory and longer expiratory time. Pes swings and PTPes_insp, two indices of inspiratory effort, were reduced by 54 (±4)% and 59 (±5)%. PTPgas_exp, an indicator of expiratory muscles activity, was completely abolished. A significant correlation was observed between the respiratory distress score and Pes swings at baseline and after nCPAP.

Conclusions

In young infants with severe acute respiratory syncytial virus bronchiolitis, nCPAP rapidly unloads respiratory muscles and improves respiratory distress symptoms.

     

Shear wave elastography of the spleen: evaluation of spleen stiffness in healthy volunteers

Purpose

The aim of this study was to assess the mean value of spleen stiffness measured by Shear wave elastography in healthy patients and its dependence on age, sex, and spleen dimensions, and to evaluate the repeatability of this method.

Methods

The final study group included 59 healthy volunteers without any clinical evidence of liver disease, portal hypertension, hematological disorders, and without any pathological ultrasonographic spleen findings. Each patient underwent abdominal ultrasound examination and elastography of the liver and the spleen.

Results

The mean value of spleen stiffness was 16.6 ± 2.5 kPa. In the group of men (N = 25), it was 17.3 ± 2.7 kPa, and in the group of women (N = 34), it was 16.1 ± 2.2 kPa. The study confirmed no correlation between spleen stiffness and sex, age of patients, and spleen size. Coefficient of repeatability and correlation coefficient between the results of the first and the second measurement showed good but not ideal repeatability of the measurement results.

Conclusion

Our outcomes may be a reference point for evaluating spleen stiffness in research on patients with various illnesses.

     

Synthetic aperture ultrasound imaging with a ring transducer array: preliminary ex vivo results

Purpose

The conventional medical ultrasound imaging has a low lateral spatial resolution, and the image quality depends on the depth of the imaging location. To overcome these problems, this study presents a synthetic aperture (SA) ultrasound imaging method using a ring transducer array.

Methods

An experimental ring transducer array imaging system was constructed. The array was composed of 2048 transducer elements, and had a diameter of 200 mm and an inter-element pitch of 0.325 mm. The imaging object was placed in the center of the ring transducer array, which was immersed in water. SA ultrasound imaging was then employed to scan the object and reconstruct the reflection image.

Results

Both wire phantom and ex vivo experiments were conducted. The proposed method was found to be capable of producing isotropic high-resolution images of the wire phantom. In addition, preliminary ex vivo experiments using porcine organs demonstrated the ability of the method to reconstruct high-quality images without any depth dependence.

Conclusion

The proposed ring transducer array and SA ultrasound imaging method were shown to be capable of producing isotropic high-resolution images whose quality was independent of depth.

     

Determination of functional residual capacity by oxygen washin-washout: a validation study

Objective

To validate a new system for functional residual capacity (FRC) measurements using oxygen washin/washout in spontaneously breathing humans. The system (LUFU, Drägerwerk AG, Lübeck, Germany) consists of an unmodified EVITA 4 ventilator, a side-stream paramagnetic oxygen sensor and a dedicated software.

Design

Laboratory study and measurements in spontaneously breathing volunteers.

Setting

Pulmonary function laboratory of a university hospital.

Participants

20 healthy and 15 lung diseased volunteers.

Interventions

FRC was measured by LUFU (LUFU-FRC) and by helium dilution (He-FRC); intra-thoracic gas volume (ITGV) was determined by body plethysmography. Each measurement cycle consisted of four independent LUFU-FRC determinations (step change of FiO₂ from 0.21 to 0.5 and back and from 0.21 to 1.0 and back), two helium-dilution runs and two body box measurements. Repeatability and agreement between methods were determined by comparing different measurements of one technique and by comparing different techniques among each other.

Measurements and results

Repeatability of LUFU-FRC was estimated by comparing washin to washout and the different FiO₂steps. The difference of the means was 3.7% at the most. Agreement between methods resulted in the following differences (mean?±?standard deviation of differences) for healthy and lung-diseased volunteers, respectively: LUFU-FRC vs. He-FRC –0.40?±?0.50?L (0.02?±?0.95?L), LUFU-FRC vs. ITGV –0.43?±?0.54?L (–0.18?±?0.61?L) and He-FRC vs. ITGV –0.03?±?0.43?L (–0.20?±?0.98?L).

Conclusions

LUFU is a non-invasive method for the determination of FRC that requires only minor additional equipment and no modification to the ventilator. It can be used in difficult conditions such as breathing patterns with variations from breath to breath. The results of this study show that LUFU is sufficiently reliable and repeatable to warrant its clinical application.

     

Clinical,Ultrasound, and Predictability Outcomes Following Certolizumab Pegol Treatment (with Methotrexate) in Patients with Moderate-to-Severe Rheumatoid Arthritis: 52-Week Results from the CZP-SPEED Study

Introduction

To assess the impact of certolizumab pegol (CZP) treatment on clinical, patient-reported, and musculoskeletal ultrasound outcomes and to determine the treatment response time point most predictive of long-term outcomes in Italian patients with rheumatoid arthritis (RA).

Methods

CZP-SPEED (NCT01443364) was a 52-week, open-label, prospective, interventional, multicenter study. Biologic-naïve patients with moderate-to-severe active RA, who had failed at least one DMARD treatment, received CZP (400 mg at weeks 0, 2, and 4, then 200 mg every 2 weeks) concomitantly with methotrexate. The primary objective was to identify the time point of clinical response {decrease in 28-joint Disease Activity Score [DAS28(ESR)]?≥?1.2} most predictive of a clinical response at week 52. Additional clinical and patient-reported outcomes were measured. Power Doppler (PD) ultrasound was used to assess synovial effusion, synovial proliferation, PD signal, cartilage damage, and bone erosion according to international guidelines.

Results

A total of 132 patients were enrolled and received CZP; 91/132 (69%) completed to week 52. Predicted 52-week responses for early responders (week 2 onwards) were between 65% and 70%. Rapid improvements in joint cavity widening and PD signal were observed to week 8 and maintained to week 52. Cartilage damage and bone erosion were stable over 52 weeks. No new safety signals were identified.

Conclusion

In Italian CZP-treated patients with moderate-to-severe RA, week 12 clinical responses may be predictive of long-term response at week 52. Rapid improvements in clinical, patient-reported, and musculoskeletal ultrasound outcomes were maintained to week 52. These data may aid rheumatologists to make earlier treatment decisions.

Trial Registration

ClinicalTrials.gov identifier, NCT01443364.

Funding

UCB Pharma.

     

Estimating needle tip deflection in biological tissue from a single transverse ultrasound image: application to brachytherapy

Purpose

This paper proposes a method to predict the deflection of a flexible needle inserted into soft tissue based on the observation of deflection at a single point along the needle shaft.

Methods

We model the needle-tissue as a discretized structure composed of several virtual, weightless, rigid links connected by virtual helical springs whose stiffness coefficient is found using a pattern search algorithm that only requires the force applied at the needle tip during insertion and the needle deflection measured at an arbitrary insertion depth. Needle tip deflections can then be predicted for different insertion depths.

Results

Verification of the proposed method in synthetic and biological tissue shows a deflection estimation error of \(<\)2 mm for images acquired at 35 % or more of the maximum insertion depth, and decreases to 1 mm for images acquired closer to the final insertion depth. We also demonstrate the utility of the model for prostate brachytherapy, where in vivo needle deflection measurements obtained during early stages of insertion are used to predict the needle deflection further along the insertion process.

Conclusion

The method can predict needle deflection based on the observation of deflection at a single point. The ultrasound probe can be maintained at the same position during insertion of the needle, which avoids complications of tissue deformation caused by the motion of the ultrasound probe.

     

Automatic adjustment of pressure support by a computer-driven knowledge-based system during noninvasive ventilation: a feasibility study

Objective

To evaluate the feasibility of using a knowledge-based system designed to automatically titrate pressure support (PS) to maintain the patient in a “respiratory comfort zone” during noninvasive ventilation (NIV) in patients with acute respiratory failure.

Design and setting

Prospective crossover interventional study in an intensive care unit of a university hospital.

Patients

Twenty patients.

Interventions

After initial NIV setting and startup in conventional PS by the chest physiotherapist NIV was continued for 45?min with the automated PS activated.

Measurements and results

During automated PS minute-volume was maintained constant while respiratory rate decreased significantly from its pre-NIV value (20?±?3 vs. 25?±?3?bpm). There was a trend towards a progressive lowering of dyspnea. In hypercapnic patients PaCO₂ decreased significantly from 61?±?9 to 51?±?2?mmHg, and pH increased significantly from 7.31?±?0.05 to 7.35?±?0.03. Automated PS was well tolerated. Two system malfunctions occurred prompting physiotherapist intervention.

Conclusions

The results of this feasibility study suggest that the system can be used during NIV in patients with acute respiratory failure. Further studies should now determine whether it can improve patient-ventilator interaction and reduce caregiver workload.

     

Outcomes Following Implantation of Two Second-Generation Trabecular Micro-Bypass Stents in Patients with Open-Angle Glaucoma on One Medication: 18-Month Follow-Up

Introduction

The study objective was to evaluate the intraocular pressure (IOP) and medication-lowering effect of 2 second-generation trabecular micro-bypass stents in eyes with open-angle glaucoma (OAG) on one preoperative medication.

Methods

Fifty-seven qualified phakic eyes with OAG on 1 medication, preoperative medicated IOP of 18–30 mmHg, and preoperative unmedicated (post-washout) IOP of 22–38 mmHg underwent implantation of 2 second-generation trabecular micro-bypass stents in a standalone procedure. Evaluations included IOP, best-corrected visual acuity, medication use, fundus and slit lamp examinations, visual field, cup to disc ratio, pachymetry, and complications and interventions. Subjects have been followed for 18 months, and follow-up is ongoing.

Results

At Month 12 postoperative, 100% of eyes had achieved an IOP reduction ≥20% (100% had IOP ≤18 mmHg and 67% had IOP ≤15 mmHg) without medication versus preoperative unmedicated IOP, and 75% had IOP reduction ≥20% without medication versus preoperative medicated IOP. The Month 12 mean unmedicated IOP had decreased by 42%, to 14.2 ± 1.9 mmHg vs 24.4 ± 1.3 mmHg preoperatively, and this reduction was maintained through 18 months (14.4 ± 2.1 mmHg). A high safety profile was observed.

Conclusion

In this prospective, open-label, single-arm study, the standalone implantation of two second-generation trabecular micro-bypass stents in OAG patients on 1 preoperative medication resulted in IOP reduction to ≤15 mmHg and elimination of medication through 18 months, with favorable safety.

Trial Registration

ClinicalTrials.gov identifier, NCT02868190.

Funding

Glaukos Corporation, San Clemente, CA.

     

Pooled Aquablation Results for American Men with Lower Urinary Tract Symptoms due to Benign Prostatic Hyperplasia in Large Prostates (60–150 cc)

Introduction

To present short-term safety and efficacy data of men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) treated with Aquablation.

Methods

Men with LUTs secondary to BPH (60–150 cc) underwent Aquablation treatment from February 2016 to December 2017 across 17 investigational sites in the USA from two contemporary investigational device exemption (IDE) studies called WATER (NCT02505919) and WATER II (NCT03123250).

Results

One hundred seven males with mean age of 67.3?±?6.5 years were treated with Aquablation; mean prostate volume was 99.4?±?24.1 cc. The pooled results show that large prostates have an average procedure time of less than 36 min and discharge on average 1.6?±?1 days. The IPSS decreased by 16.7?±?8.1 points at 3 months and Q_max increased by 11.2?±?12.4 ml/s. The Clavien-Dindo (CD) grade 2 or higher event rate at 3 months was 29%. A non-hierarchical breakdown for CD events yielded 18% grade 2 and 19% grade 3 or higher.

Conclusion

Men with LUTS secondary to BPH (60–150 cc) in a pooled analysis were treated safely and effectively with Aquablation up to 3 months postoperatively.

Trial Registration

ClinicalTrials.gov identifiers, NCT02505919 and NCT03123250.

Funding

PROCEPT BioRobotics.

     

Regional lung derecruitment after endotracheal suction during volume- or pressure-controlled ventilation: a study using electric impedance tomography

Objective

To assess lung volume and compliance changes during open- and closed-system suctioning using electric impedance tomography (EIT) during volume- or pressure-controlled ventilation.

Design and setting

Experimental study in a university research laboratory.

Subjects

Nine bronchoalveolar saline-lavaged pigs.

Interventions

Open and closed suctioning using a 14-F catheter in volume- or pressure-controlled ventilation at tidal volume 10?ml/kg, respiratory rate 20?breaths/min, and positive end-expiratory pressure 10?cmH₂O.

Measurements and results

Lung volume was monitored by EIT and a modified N₂ washout/-in technique. Airway pressure was measured via a pressure line in the endotracheal tube. In four ventral-to-dorsal regions of interest regional ventilation and compliance were calculated at baseline and 30?s and 1, 2, and 10?min after suctioning. Blood gases were followed. At disconnection functional residual capacity (FRC) decreased by 58?±?24% of baseline and by a further 22?±?10% during open suctioning. Arterial oxygen tension decreased to 59?±?14% of baseline value 1?min after open suctioning. Regional compliance deteriorated most in the dorsal parts of the lung. Restitution of lung volume and compliance was significantly slower during pressure-controlled than volume-controlled ventilation.

Conclusions

EIT can be used to monitor rapid lung volume changes. The two dorsal regions of the lavaged lungs are most affected by disconnection and suctioning with marked decreases in compliance. Volume-controlled ventilation can be used to rapidly restitute lung aeration and oxygenation after lung collapse induced by open suctioning.

     

Effect of synbiotic therapy on the incidence of ventilator associated pneumonia in critically ill patients: a randomised,double-blind,placebo-controlled trial

Objective

To investigate the effect of enteral Synbiotic 2000 FORTE^® (a mixture of lactic acid bacteria and fibre) on the incidence of ventilator associated pneumonia (VAP) in critically ill patients.

Design

Prospective, randomised, double blind, placebo controlled trial.

Setting

Tertiary referral centre, general Adult Intensive Care Unit (ICU).

Patients and participants

259 enterally fed patients requiring mechanical ventilation for 48 h or more were enrolled.

Intervention

All patients were enterally fed as per a standard protocol and randomly assigned to receive either synbiotic 2000 FORTE^® (twice a day) or a cellulose-based placebo for a maximum of 28 days.

Measurements and results

Treatment group (n = 130) was well matched with placebo group (n = 129) for age (mean 49.5 and 50 years, respectively) and APACHE II score (median 17 for both). Oropharyngeal microbial flora and colonisation rates were unaffected by synbiotics. The overall incidence of VAP was lower than anticipated (11.2%) and no statistical difference was demonstrated between groups receiving synbiotic and placebo in the incidence of VAP (9 and 13%, P = 0.42), VAP rate per 1,000 ventilator days (13 and 14.6, P = 0.91) or hospital mortality (27 and 33%, P = 0.39), respectively.

Conclusions

Enteral administration of Synbiotic 2000 FORTE^® has no statistically significant impact on the incidence of VAP in critically ill patients.

     

Efficacy of the echo pattern classification of ovarian tumors 2000 in conjunction with transvaginal ultrasonography for diagnosis of ovarian masses

Purpose

Because of the need for rapid, accurate clinical differentiation between malignant and benign ovarian masses, we investigated the diagnostic efficacy of the echo pattern classification used together with transvaginal ultrasound.

Methods

We classified, on the basis of six echo pattern types, transvaginal ultrasound images of 405 ovarian masses treated surgically between January 2011 and December 2012. We compared the resulting classifications to the postoperative histopathologic diagnoses and computed the diagnostic sensitivity and specificity of the echo pattern-based classification for malignancy.

Results

Our review yielded the following echo patterns: type I, n = 61; type II; n = 154; type III, n = 82; type IV, n = 61; type V, n = 34; and type VI, n = 13. Histopathologically, there were 75 borderline malignant/malignant tumors and 330 benign tumors. Diagnostic sensitivity was 80.0 % and specificity was 85.5 % when echo types I–III were categorized as benign and types IV–VI were categorized as malignant. Further, with respect to benign tumors: sensitivity and specificity for chocolate cysts were 85.5 and 88.4 %, respectively, and for dermoid cysts were 67.2 and 97.9 %, respectively.

Conclusions

With the echo pattern classification, ovarian masses can be diagnosed easily and accurately upon transvaginal ultrasound.