Effect of residual volume after surgery of the discoid lateral meniscus on tibiofemoral joint biomechanics: a finite element analysis

BACKGROUND

The purpose of this study was to investigate the influence of different residual meniscus volume on the biomechanics of tibiofemoral joint after discoid lateral meniscus (DLM) surgery by finite element analysis.

METHODS

A knee joint model was established based on CT and MRI imaging data. The DLM model was divided into five regions according to conventional meniscectomy, with volumes of 15%, 15%, 15%, 15%, 15%, and 40% for each region. Additionally, the DLM model was divided into anterior and posterior parts to obtain ten regions. The DLM was resected according to the design scheme, and together with the intact discoid meniscus, a total of 15 models were obtained. Finite element analysis was conducted to assess shear and pressure trends on the knee joint.

RESULTS

The study observed significant changes in peak shear stress and compressive stress in the lateral meniscus and lateral femur cartilage. As the meniscus volume decreased, there was an increase in these stresses. Specifically, when the meniscus volume reduced to 40%, there was a sharp increase in shear stress (302%) and compressive stress (152%) on the meniscus, as well as shear stress (195%) and compressive stress (157%) on the lateral femur cartilage. Furthermore, the model grouping results showed that preserving a higher frontal volume in the meniscus model provided better biomechanical advantages.

CONCLUSION

The use of finite element analysis has demonstrated that preserving more than 55% of the meniscus volume is necessary to prevent a significant increase in joint stress, which can potentially lead to joint degeneration. Additionally, it is crucial to preserve the front volume of the DLM in order to achieve improved knee biomechanical outcomes.

Accuracy, Precision, and Residual Volume of Commonly Used Syringes for Intravitreal Injections and the Impact on Intraocular Pressure

PURPOSE

To compare accuracy, precision, and residual volume of commonly used syringes for intravitreal injections (IVIs) and to assess the intraocular pressure (IOP) rise by variations in volumes delivered.

DESIGN

Experimental laboratory study.

SUBJECTS

No subjects were involved in this study.

METHODS

We tested 8 syringe models with 2 different needle setups, with 2 different solutions (distilled water or glycerin) and target volumes (50 and 70 μL). To obtain the delivered and residual volumes, we weighed the syringe-needle setups with scale before liquid withdrawal, with liquid, and after liquid release. We also created an experimental eye model to determine the transient rise in IOP following stepwise 10-μL increases in injection volumes.

MAIN OUTCOME MEASURES

Delivered and residual volumes, IOP rise.

RESULTS

We tested a total of 600 syringe-needle setups. Becton Dickinson (BD) Ultra-Fine (0.34 ± 0.28 μL), Zero Residual (1.53 ± 1.15 μL), and Zero Residual Silicone Oil-free (1.40 ± 1.16 μL) syringes showed the lowest residual volume (P < 0.001) in comparison with the others (range: 24.86 ± 1.78 μL for Injekt-F to 51.97 ± 3.37 μL for Omnifix-F). The most accurate setups were (percentage deviation from target volume): Zero Residual Silicone Oil-free (+ 0.70%), Zero Residual 0.3 ml (+ 4.49%), BD Ultra-Fine (+ 7.83%), Injekt-F (9.42%), Norm-Ject (+ 15.88%), Omnifix-F (+ 16.96%), BD Plastipak Brazil (+17.96%), and BD Plastipak Spain syringes (+ 19.41%). There was a statistically significant difference between the Zero Residual Silicone Oil-free syringe and all other syringes (P < 0.0001), except for the Zero Residual 0.3-ml syringe (P = 0.029). The coefficient of variation was low for all syringes. The modeled IOP rise ranged from 32.3 (standard deviation [SD], 1.4) mmHg for 20-μL injection volume to 76.5 (SD, 1.0) mmHg for 80-μL injection volume. For the standard 50-μL injection volume, the peak pressure was 50.7 (SD, 0.1) mmHg, and the pressure rise duration was 28 (SD, 2) minutes.

CONCLUSIONS

There were significant differences in accuracy and residual volume between syringes, whereas they showed a high precision. Volume excess results in a considerable increase in IOP rise after injection. These findings may provide a relevant overview to clinicians and to both device and drug manufacturers regarding pharmacoeconomic, safety, and efficacy issues.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Influence of peritoneal residual volume on the results of the peritoneal equilibration test. Prospective study

BACKGROUND

Categorization of the capacity of ultrafiltration during a peritoneal equilibration test (PET) is a usual step during the monitoring of peritoneal transport characteristics of Peritoneal Dialysis (PD) patients. Quantifying the peritoneal residual volume (Vr) after the dwell preceding the PET (Vrpre) and at the end of the test (Vrpost) could help to improve the accuracy of the estimation of this variable.

METHOD

Following a prospective design, we calculated Vrpre and Vrpost in 116 patients, incident or prevalent on DP, who underwent one or two (n = 27) PET with 3,86/4,25% glucose-based PD solutions and complete drainage at 60 min. We evaluated the consistency of Vr by comparing Vrpre and Vrpost, as also these two parameters in repeated tests. We scrutinized potential associations between demographic and clinical factors, on one side, and the amount of Vr on the other, as also the impact of correcting ultrafiltration during PET for Vr on the categorization of the capacity of ultrafiltration.

RESULTS

As a mean, Vrpost was larger than Vrpre. Consequently, correction of ultrafiltration for Vr resulted in significantly higher values than those obtained according to the standard procedure (494 vs. 449 mL, p < 0,0005). We disclosed marked inconsistencies for different estimations of Vr in the same patients (Vrpre vs Vrpost and repeated PET studies). Moreover, no demographic or clinical variable was able to predict the amount of Vr. We observed a significant deviation (>200 mL) between both methods of estimation of the capacity of utrafiltration in only 12,9% of the patients. However, 21,1% of the patients categorized as cases of ultrafiltration failure according to the standard procedure did not maintain this condition after correction for Vr.

CONCLUSIONS

Correction for Vr of the capacity of ultrafiltration during a PET carries, as a mean, a minor impact on the categorization of this parameter. However, the results of the test can be significantly affected in 12,9% of the cases. We have been unable to detect demographic or clinical predictors of Vr, which suggests a random component for the mechanics of single peritoneal exchanges. We suggest that Vr should be estimated at the time of categorizing the capacity of ultrafiltration, whenever inconsistencies during serial PET studies are detected.

Air pollution enhance the progression of restrictive lung function impairment and diffusion capacity reduction: an elderly cohort study

BACKGROUND

Some evidences have shown the association between air pollution exposure and the development of interstitial lung diseases. However, the effect of air pollution on the progression of restrictive ventilatory impairment and diffusion capacity reduction is unknown. This study aimed to evaluate the effects of long-term exposure to ambient air pollution on the change rates of total lung capacity, residual volume, and diffusion capacity among the elderly.

METHODS

From 2016 to 2018, single-breath helium dilution with the diffusion capacity of carbon monoxide was performed once per year on 543 elderly individuals. Monthly concentrations of ambient fine particulate matters (PM_2.5) and nitric dioxide (NO₂) at the individual residential address were estimated using a hybrid Kriging/Land-use regression model. Linear mixed models were used to evaluate the association between long-term (12 months) exposure to air pollution and lung function with adjustment for potential covariates, including basic characteristics, indoor air pollution (second-hand smoke, cooking fume, and incense burning), physician diagnosed diseases (asthma and chronic airway diseases), dusty job history, and short-term (lag one month) air pollution exposure.

RESULTS

An interquartile range (5.37 ppb) increase in long-term exposure to NO₂ was associated with an additional rate of decline in total lung volume (- 1.8% per year, 95% CI: - 2.8 to - 0.9%), residual volume (- 3.3% per year, 95% CI: - 5.0 to - 1.6%), ratio of residual volume to total lung volume (- 1.6% per year, 95% CI: - 2.6 to - 0.5%), and diffusion capacity (- 1.1% per year, 95% CI: - 2.0 to - 0.2%). There is no effect on the transfer factor (ratio of diffusion capacity to alveolar volume). The effect of NO₂ remained robust after adjustment for PM_2.5 exposure.

CONCLUSIONS

Long-term exposure to ambient NO₂ is associated with an accelerated decline in static lung volume and diffusion capacity in the elderly. NO₂ related air pollution may be a risk factor for restrictive lung disorders.

Small Airways: Not Just Air Ducts - Pathophysiological Aspects and Clinical Implications

The airways smaller than 2 mm diameter are named small airways. They are essential for the transport and exchange of oxygen and carbon dioxide and at the same time play a relevant role in pulmonary mechanics, contributing to the subdivision of lung volumes. Measurement of small airway function is, therefore, crucial in patients with respiratory disease. This overview focuses on the physiological aspects of the small airways, considered as air ducts as well as determinants of pulmonary mechanics, the most common tools for evaluating their function and treatment implications.

Large tumour volume reduction of IDH-mutated anaplastic glioma involving the insular region following radiotherapy

Background

The impact of near-total resection of IDH-mutated anaplastic glioma (IDHmutAG) is well-established but there remains uncertainty of benefit in tumours of the insular cortex where the extent of safe resection may be limited. This study aimed to assess tumour volume reduction in patients following IMRT and impact of residual post-surgical volume.

Methods and materials

Patients with IDHmutAG involving insular cortex managed with IMRT from 2008 to 2019 had baseline patient, tumour and treatment factors recorded. Volumetric assessment of residual disease on MRI was performed at baseline, month+ 3 and month+ 12 post-IMRT. Potential prognostic factors were analysed for tumour reduction and relapse-free survival, and assessed by log-rank and Cox regression analyses.

Results

Thirty two patients with IDHmutAG of the insular cortex were managed with median follow-up post-IMRT of 67.2 months. Pathology was anaplastic astrocytoma (AAmut) in 20, and anaplastic oligodendroglioma (AOD) in 12 patients. Median pre-IMRT volume on T1 and T2Flair was 24.3cm³ and 52.2cm³. Twenty-seven patients were alive with 5-year relapse-free survival of 80%. There was a median 67 and 64% reduction from baseline occurring at 3 months post-IMRT for T1 and T2Flair respectively; and subsequent median 78 and 73% at 12 months. At 12 months AOD patients had median 83% T1 volume reduction compared to 63% in AAmut (p < 0.01). There was no difference on T2Flair volume (p = 0.64). No other pathological factors influenced volume reduction at 12 months. No factors were associated with relapse-free survival including baseline T1 (p = 0.52) and T2Flair (p = 0.93) volume.

Conclusion

IMRT provides large tumour volume reduction in IDHmutAG of the insular cortex. While maximal safe debulking remains standard of care when feasible, this patient cohort reported no significant negative impact of residual disease volume on relapse-free survival.

Susceptibility of individuals with lung dysfunction to systemic inflammation associated with ambient fine particle exposure: A panel study in Beijing

BACKGROUND

The underlying mechanism on the susceptibility of chronic obstructive pulmonary disease (COPD) patients to air pollution has yet to be clarified.

OBJECTIVES

Based on the COPD in Beijing (COPDB) study, we examined whether lung dysfunction contributed to pollutant-associated systemic inflammation in COPD patients.

METHODS

Proinflammatory biomarkers including interleukin-8 (IL-8) and tumor necrosis factor α (TNFα) were measured in serum samples collected from 53 COPD and 82 healthy participants. Concentrations of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM_2.5), carbonaceous components in PM_2.5, and PM size distribution were continuously monitored. Linear mixed effects models were used to examine the associations of biomarker differences with particle exposure, between COPD and healthy participants, and across subgroups with different levels of lung dysfunction.

RESULTS

COPD patients showed higher differences in IL-8 and TNFα levels associated with exposure to measured pollutants, comparing to healthy controls. In advanced analysis, particle-associated differences in IL-8 and TNFα levels were higher in participants with poorer lung ventilation and diffusion capacity, and higher ratio of residual volume. For example, an interquartile range increase in average PM_2.5 concentration 2 weeks before visits was associated with a 15.7% difference in IL-8 level in participants with the lowest ratio of measured value to predicted value of forced expiratory volume in 1 s (FEV1%pred) (65.2%), and the association decreased monotonically with increasing FEV1%pred. Associations between differences in TNFα level and average ultrafine particle concentration 1 week before visits increased gradually with increasing ratio of measured value to predicted value of residual volume/total lung capacity.

CONCLUSIONS

COPD patients, especially those with poorer lung function, are more susceptible to systemic inflammation associated with fine particle exposure.

Residual Volume Responsiveness Testing May Improve the Detection of Reversible Airway Obstruction in Asthma

BACKGROUND

Residual volume responsiveness to bronchodilator administration has been observed in subjects with chronic obstructive pulmonary disease. However, the prevalence of residual volume (RV) responsiveness has not been formally studied in asthma.

OBJECTIVE

To identify the prevalence and magnitude of RV responsiveness in asthma.

METHODS

Physician-diagnosed adult subjects with asthma on treatment for >12 months were prospectively recruited to perform spirometry and measurement of lung volumes using body plethysmography before and after administration of 360 μg of albuterol.

RESULTS

Among 120 subjects, 76% were women. The ethnic composition was 64% Caucasian, 32% Hispanic, and 13% African American. The mean age was 52 ± 15 years. The mean duration of asthma was 16 ± 15 years. The mean RV% responsiveness was -7.74 ± 14. Whereas patients with the lowest baseline forced expiratory volume in 1 second (FEV1) value showed the highest mean responsiveness (P = .001), the baseline RV value had minimal influence on RV responsiveness. Using -7.74% to define significant RV responsiveness, and ≥12% and ≥200 mL to define significant FEV1 responsiveness, more subjects showed isolated RV responsiveness (37%) compared with 6% with isolated FEV1 responsiveness and 14% with both FEV1 and RV responsiveness (P = .04). There was a minimal correlation between FEV1 responsiveness and RV responsiveness (r = 0.17, P = .06). The RV responsiveness was significantly associated with the wheeze score (P = .006) and dyspnea score (P = .029).

CONCLUSION

The addition of RV responsiveness testing to spirometry based responsiveness testing can improve the identification of reversible airway obstruction in asthma. RV responsiveness may be useful in monitoring symptoms associated with air trapping in asthma.

Endobronchial Valve (Zephyr) Treatment in Homogeneous Emphysema: One-Year Results from the IMPACT Randomized Clinical Trial

RATIONALE

The long-term safety and effectiveness of bronchoscopic lung volume reduction with Zephyr endobronchial valves in subjects with severe homogeneous emphysema with little to no collateral ventilation beyond 3 months have yet to be established.

METHODS

Ninety-three subjects were randomized to either bronchoscopic lung volume reduction with Zephyr valves or standard of care (SoC) (1:1). Zephyr valve subjects were assessed at 3, 6, and 12 months. SoC subjects were assessed at 3 and 6 months; they were then offered crossover to Zephyr valve treatment.

RESULTS

The mean group difference (Zephyr valve - SoC) for change in FEV1 from baseline to 6 months was 16.3 ± 22.1% (mean ± SD; p < 0.001). Secondary outcomes showed the mean between-group difference for the six-minute walk distance of +28.3 ± 55.3 m (p = 0.016); St. George's Respiratory Questionnaire, -7.51 ± 9.56 points (p < 0.001); modified Medical Research Council, -0.42 ± 0.81 points (p = 0.019); BODE index, -0.85 ± 1.39 points (p = 0.006); and residual volume of -430 ± 830 mL (p = 0.011) in favor of the Zephyr valve group. At 6 months, there were significantly more responders based on the minimal clinically important difference for these same measures in the Zephyr valve versus the SoC group. The clinical benefits were persistent at 12 months. The percentage of subjects with respiratory serious adverse events was higher in the Zephyr valve group compared to SoC during the first 30 days post-procedure but not statistically different for the Zephyr valve and SoC groups from 31 days to 6 months, and stable in the Zephyr valve group out to 12 months. There were 2 deaths in the SoC group in the 31-day to 6-month period and none in the Zephyr valve group out to 12 months.

CONCLUSIONS

Bronchoscopic lung volume reduction with Zephyr valves in subjects with severe homogeneous emphysema and little to no collateral ventilation provides clinically meaningful change from baseline in lung function, quality of life, exercise capacity, dyspnea, and the BODE index at 6 months, with benefits maintained out to 12 months.

Efficacy of Nebulized Glycopyrrolate on Lung Hyperinflation in Patients with COPD

Introduction

Lung hyperinflation in chronic obstructive pulmonary disease (COPD) is associated with activity limitation, impaired cardiac output, and mortality. Several studies have demonstrated that long-acting muscarinic antagonists (LAMAs) delivered by dry powder inhalers can promote lung deflation; however, the potential of nebulized LAMAs on improving hyperinflation in COPD is currently unknown.

Methods

This single-center, randomized, double-blind, two-way crossover study (NCT04155047) evaluated the efficacy of a single dose of nebulized LAMA [glycopyrrolate (GLY) 25 µg] versus placebo in patients with COPD and lung hyperinflation. Patients with moderate-to-severe COPD and a residual volume (RV) ≥ 130% of predicted normal were included. The primary endpoint was changed from baseline in RV at 6 h post-treatment. Other endpoints included changes from baseline in spirometric and plethysmographic measures up to 6 h post-treatment.

Results

A total of 22 patients (mean pre-bronchodilator RV, 153.7% of predicted normal) were included. The primary objective of the study was not met; the placebo-adjusted least squares (LS) mean [95% confidence interval (CI) change from baseline in RV with GLY at 6 h post-treatment was − 0.323 l (− 0.711 to 0.066); p = 0.0987]. A post hoc evaluation of the primary analysis was conducted after excluding a single statistical outlier; substantial improvements in RV with GLY compared with placebo was observed after exclusion of this outlier [placebo-adjusted LS mean change from baseline (95% CI) in RV was − 0.446 l (− 0.741 to − 0.150)]. Improvements from baseline were also observed with GLY compared with placebo in spirometric and plethysmographic measures up to 6 h post-treatment. GLY was generally safe, and no new safety signals were detected.

Conclusions

This is the first study to evaluate the effect of nebulized GLY on lung deflation. Nebulized GLY resulted in marked improvements in RV up to 6 h post-treatment, compared with placebo. Improvements were also observed with GLY in spirometric and plethysmographic parameters of lung function.

Trial Registration

ClinicalTrials.gov identifier, NCT04155047.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00166-5.

Clinical impact of long-term change in air trapping on pulmonary function and computed tomography parameters in chronic obstructive pulmonary disease

BACKGROUND/AIMS

Air trapping is associated with unfavorable outcomes in chronic obstructive pulmonary disease (COPD). The present study evaluated the association between longitudinal changes in air trapping with pulmonary function, computed tomography (CT) parameters and exacerbation.

METHODS

Patients enrolled in the Korean Obstructive Lung Disease (KOLD) study cohort from June 2005 to October 2015 were included. The study patients were categorized into four groups according to the change in residual volume to total lung capacity ratio (RV/TLC) over 3 years. The RV/TLC was considered abnormal when it was ≥ 40% and normal when it was < 40%.

RESULTS

A total of 279 patients were categorized into four groups: 76 in the "normal to normal" (N→N) group, 34 in the "abnormal to normal" (A→N) group, 33 in the "normal to abnormal" (N→A) group, and 136 in the "abnormal to abnormal" (A→A) group. For forced expiratory volume in 1 second and forced vital capacity (FVC), respectively, group A→N showed a large increase of 266 mL (p < 0.001) and 381 mL (p < 0.001), group N→A showed a marked decrease of 216 mL (p < 0.001) and 332 mL(p = 0.029), and group A→A showed a decrease of 16 mL (p = 0.426) and 6 mL (p = 0.011) compared to group N→N. Group A→N showed a significant decrease of -0.013 in expiratory to inspiratory ratio of the mean lung density (p < 0.001), while group A→N showed an increase of 0.005 (p < 0.001).

CONCLUSION

Patients with COPD whose RV/TLC changed from normal to abnormal showed deterioration of pulmonary function and worsening of CT parameters simultaneously.

[The end-tidal carbon dioxide as an early sign and predictor of the return of spontaneous circulation during out-of-hospital cardiac arrest. A systematic review.]

BACKGROUND

There is no clear evidence on the maximum level of end-tidal carbon dioxide (ETCO₂) predictor of the return of spontaneous circulation (RSC) after an out-of-hospital cardiorespiratory arrest. The aims of this work was to synthesise and analyse the available evidence on the usefulness of monitoring values ETCO₂ in an out-of-hospital cardiorespiratory arrest as an early sign and prognostic indicator of the RSC.

METHODS

Systematic review, with narrative synthesis of the results, of primary studies published in English or Spanish was conducted in Medline, CINAHL, Web of Science, EMBASE, Proquest, Scopus, Cochrane, ÍnDICEs CSIC and CUIDEN of studies that analyse the usefulness of monitoring of the level of ETCO₂ as a sign of the RSC after an out-of-hospital cardiorespiratory arrest. PRISMA declaration was followed. The risk of bias was assessed with the Newcastle-Ottawa Scale.

RESULTS

1,011 studies were found, eight of which fulfilled the inclusion criteria. The studies reported an association between the abrupt increase in ETCO₂ and RSC to disagree on the predictive cut-off points (an increase than 10 mmHg and initial values or three minutes greater than 10 mmHg or 19 mmHg). The studies were of moderate to high methodological quality.

CONCLUSIONS

ETCO₂ values correlate with the RSC in adults with cardiorespiratory arrest and could predict non-survival, so they should be incorporated into advanced life support algorithms and Utstein-style reports.

The effects of residual parotid volume on symptom-specific quality of life and complications in patients undergoing parotid surgery

PURPOSE

To measure postoperative residual parotid volumes in parotidectomy patients and to measure the effect of residual parotid volumes on the symptom-specific quality of life (SSQOL) and complications.

METHODS

Between January 2010 and December 2016, 148 parotid gland surgeries were performed, and 74 patients were included in the study. Bilateral parotid gland volumes were measured by Magnetic Resonance Imaging (MRI). Parotidectomy Outcome Inventory-8 and aesthetic scale questionnaire were applied to the patients. The volumetric averages obtained were compared with the questions in the SSQOL scale, the aesthetic scale data, and complications.

RESULTS

In the volumetric examination performed with MRI, the mean residual volumes of the operated parotid glands were 9.5 cm³, while the non-operated side was 28.8 cm³. The width of the surgery and the residual parotid tissue volume was inversely correlated. There was a statistically significant difference between the residual parotid gland volume and the pain related to the surgical area, depression in the surgical site, Frey's syndrome, incision scar, and numbness. As the residual parotid gland volumes decreased, the patients' cosmetic problems related to the surgical field increased significantly, and their SSQOL decreased.

CONCLUSION

Postoperative residual parotid tissue volume could be an objective parameter to measure patients' SSQOL and complications. After parotidectomy, the maximum amount of disease-free tissue of the parotid gland should be left in place to increase patients' quality of life and minimize complications.

Determining Static Hyperinflation in Patients with Severe Emphysema: Relation Between Lung Function Parameters and Patient-Related Outcomes

BACKGROUND

Bronchoscopic lung volume reduction techniques are minor invasive treatment modalities for severely hyperinflated emphysema patients. The severity of static lung hyperinflation determines eligibility and success rate for these treatments. However, it is not exactly known what parameter should be used to optimally reflect hyperinflation. Commonly used parameters are residual volume (RV) and the RV/Total lung capacity (TLC) ratio. Other parameters reflecting hyperinflation are Inspiratory Capacity/TLC and forced vital capacity.

OBJECTIVES

To define which of these function parameters is the most optimal reflection of hyperinflationin in relation to patient-related outcomes.

METHODS

In a retrospective cohort study, data from measurements during baseline visits of eight studies were pooled. Primary outcomes were RV/TLC ratio and RV as percentage of predicted (RV%pred), both measured by bodyplethysmography, compared to the patient-related outcome variables: 6-min walk distance (6MWD), the St. George's Respiratory Questionnaire (SGRQ), and the modified Medical Research Council (mMRC).

RESULTS

Two hundred seventy-four COPD patients (mean age 59 years; 66% female), FEV₁ 0.74 ± 0.28 L, RV 4.94 ± 1.06 L, 6MWD of 339 ± 95 m, were included in the analysis. Significant correlations (all p < 0.01) were found between RV%pred and 6MWD (r =  - 0.358), SGRQ (r = 0.184), and mMRC (r = 0.228). Also, there was a significant correlation between RV/TLC ratio and 6MWD (r =  - 0.563), SGRQ (r = 0.289) and mMRC (r = 0.354). Linear regression analyses showed that RV/TLC ratio was a better predictor of patient outcomes than RV%pred.

CONCLUSION

This study demonstrates that both RV/TLC ratio and RV%pred are relevant indicators of hyperinflation in patients with severe emphysema in relation to patient-related outcomes. RV/TLC ratio is more strongly related to the patient-related outcomes than RV%pred.

Glioblastoma survival is better analyzed on preradiotherapy MRI than on postoperative MRI residual volumes: A retrospective observational study

OBJECTIVES

Establishing an overall survival prognosis for resected glioblastoma during routine postoperative management remains a challenge. The aim of our single-center study was to assess the usefulness of basing survival analyses on preradiotherapy MRI (PRMR) rather than on postoperative MRI (POMR).

PATIENTS AND METHODS

A retrospective review was undertaken of 75 patients with glioblastoma treated at our institute. We collected overall survival and MRI volumetric data. We analyzed two types of volumetric data: residual tumor volume and extent of resection. Overall survival rates were compared according to these two types of volumetric data, calculated on either POMR or PRMR and according to the presence or absence of residual enhancement.

RESULTS

Analysis of volumetric data revealed progression of some residual tumors between POMR and PRMR. Kaplan-Meier analysis of the correlations between extent of resection, residual tumor volume, and overall survival revealed significant differences between POMR and PRMR data. Both MRI scans indicated a difference between the complete resection subgroup and the incomplete resection subgroup, as median overall survival was longer in patients with complete resection. However, differences were significant for PRMR (25.3 vs. 15.5, p =  0.012), but not for POMR (21.3 vs. 15.8 months, p =  0.145). With a residual tumor volume cut-off value of 3 cm³, Kaplan-Meier survival analysis revealed non-significant differences on POMR (p =  0.323) compared with PRMR (p =  0.007).

CONCLUSION

Survival in patients with resected glioblastoma was more accurately predicted by volumetric data acquired with PRMR. Differences in predicted survival between the POMR and PRMR groups can be attributed to changes in tumor behavior before adjuvant therapy.

Is there any correlation between HPV and early radioresponse before brachytherapy in cervix uteri carcinoma?

OBJECTIVE

The prognostic effect of human papilloma virus (HPV) on early radioresponse before brachytherapy was evaluated in locally advanced cervix uteri carcinoma patients.

METHODS

Between 2015 and 2018, 150 patients with locally advanced carcinoma of the cervix uteri from University of Health Sciences Okmeydani Training and Research Hospital and Istanbul Oncology Hospital underwent chemotherapy concomitant with external radiotherapy and brachytherapy after performing fluorodeoxyglucose positron emission tomography (FDG PET) and magnetic resonance imaging (MRI) for purposes of staging and treatment planning. The treatment results of patients analyzed retrospectively.

RESULTS

The median age of 57 patients was 53 years, and the initial tumor volume was 27 cm³. The median follow-up period was 22 months. The median tumor volume after external radiotherapy was significantly higher in patients without local control than those who responded to external radiotherapy (p = 0.031). The mean tumor diameter and volume in all HPV-negative patients after external radiotherapy were significantly higher than those of HPV-positive patients (p = 0.011 and p = 0.046, respectively). In a group of patients with poor early responses, local disease control could not be achieved despite the use of recommended higher doses of brachytherapy.

CONCLUSION

We could not determine the correlation between HPV contamination and patients who had early response intervention. But residual tumor of more than 2 cm in diameter after external radiotherapy may be a predictor of failed local control and development of metastasis within a short time.

Effects of Osteopathic Manual Therapy on Hyperinflation in Patients with Chronic Obstructive Pulmonary Disease: A Randomized Cross-Over Study

Osteopathic manual therapy (OMT) may reduce hyperinflation in patients with chronic obstructive pulmonary disease (COPD) by improving breathing mechanics. The aim of the study was to evaluate the immediate effects of OMT on hyperinflation in stable COPD patients with forced expired volume in 1 s (FEV₁) <50% predicted. Nineteen COPD patients of the median age 68 (IQR 63-72) years and the median FEV₁ 39.8 (IQR 33.4-46.6) % predicted were enrolled into the study. For the first session, patients were randomly assigned to either OMT or sham therapy. During the second session, the two groups of patients were crossed over. Pulmonary function and dyspnea were compared before and after both procedures. Neither pulmonary function nor dyspnea differed significantly before and after OMT or sham procedures. However, 36.7% and 47.4% patients achieved the minimally important difference for residual volume (RV) reduction after both OMT and sham therapy, respectively. Responders to OMT had a greater median (IQR) baseline sense of dyspnea compared to non-responders, assessed on a visual analog scale, of 7.0 (4.5-7.0) vs. 3.0 (0.0-5.0), p = 0.040, respectively. Although OMT did not have an immediate effect on hyperinflation or dyspnea, a subgroup experienced a reduction in RV following OMT and sham therapy. Future studies are needed to identify the characteristics of responders.

Significant Differences in Body Plethysmography Measurements Between Hospitals in Patients Referred for Bronchoscopic Lung Volume Reduction

During the evaluation of potential bronchoscopic lung volume reduction (BLVR) candidates in our hospital, we frequently observe patients with a lower residual volume (RV) value compared to the value measured in their referring hospital, although both measured by body plethysmography. We explored to what degree RV and other pulmonary function measurements match between referring hospitals and our hospital. We retrospectively analyzed a total of 300 patients with severe emphysema [38% male, median age 62 years (range 38-81), median forced expiratory volume in 1 s 29% (range 14-65) of predicted, and a median of 40 packyears (range 2-125)]. We measured a median RV of 4.47 l (range 1.70-7.57), which was a median 310 ml lower than in the referring hospitals (range - 3.04 to + 1.94), P < 0.001). In conclusion, this retrospective analysis demonstrated differences in RV measurements between different hospitals in patients with severe emphysema. Overestimation of RV can lead to unnecessary referrals for BLVR and potential treatment failures. To avoid disappointment and unnecessary hospital visits, it is important that body plethysmography measurements are accurately performed by applying preferably the unlinked method in these patients.

The effects of position on gastric residual volume of premature infants in NICU

Background

Nutrition cares are of the main measures to save premature infants. In this regard, proper positioning is one of the key measures that is done by nurses; still there is a paucity of studies in this field and the results of these few studies are an area of ongoing debates. In light of this, the present paper is an attempt to determine the effects of different positioning on gastric residual volume in premature infants in NICU.

Methods

A clinical trial cross-over study was carried out on premature infants in NICU. The subjects, who had inclusion criteria, were selected through convenience sampling based on inclusion criteria and randomly allocated into three groups. Gastric residual volume before and one hours after feeding was measured and recorded for three positions including right-lateral, left-lateral, and prone. The data was analyzed via SPSS-21 using descriptive statistics such as mean, standard deviation, and frequency; and inferential statistics such as Chi Squared, Kruskal Wallis test, and Friedman test.

Results

Totally, 135 infants in three groups were studied and the results showed that minimum and maximum gastric residual volumes were in prone (6.49 ± 8.25 ML) and supine (12.59 ± 11.9 ML) positions, respectively. However, Kruskal Wallis test did not show a significant relationship between the three positions under study and the mean gastric residual volume.

Conclusion

Prone position was featured with the lowest gastric residual volume and highest possibility of absorbing nutrient. Still, given the fact that no significant difference was found in the three groups, further and deeper studies are needed.

Trial registration

The project is approved by Iranian Registry of Clinical Trial with no. IRCT. 201404134736 N6.

A comprehensive approach to lung function in bronchiectasis

BACKGROUND

International guidelines recommend simple spirometry for bronchiectasis patients. However, pulmonary pathophysiology of bronchiectasis is very complex and still poorly understood. Our objective was to characterize lung function in bronchiectasis and identify specific functional sub-groups.

METHODS

This was a multicenter, prospective, observational study enrolling consecutive adults with bronchiectasis during stable sate. Patients underwent body-plethysmography before and after acute bronchodilation testing, diffusing lung capacity (DLCO) with a 3-year follow up. Air trapping and hyperinflation were a residual volume (RV) > 120%predicted and a total lung capacity>120%predicted. Acute reversibility was: ΔFEV1 ≥12% and 200 mL from baseline (FEV1rev) and ΔRV ≥10% reduction from baseline (RVrev). Sensitivity analyses included different reversibility cutoffs and excluded patients with concomitant asthma or chronic obstructive pulmonary disease.

RESULTS

187 patients were enrolled (median age: 68 years; 29.4% males). Pathophysiological abnormalities often overlapped and were distributed as follows: air trapping (70.2%), impaired DLCO (55.7%), airflow obstruction (41.1%), hyperinflation (15.7%) and restriction (8.0%). 9.7% of patients had normal lung function. RVrev (17.6%) was more frequent than FEV1rev (4.3%). Similar proportions were found after multiple sensitivity analyses. Compared with non-reversible patients, patients with RVrev had more severe obstruction (mean(SD) FEV1%pred: 83.0% (24.4) vs 68.9% (26.2); P = 0.02) and air trapping (RV%pred, 151.9% (26.6) vs 166.2% (39.9); P = 0.028).

CONCLUSIONS

Spirometry alone does not encompass the variety of pathophysiological characteristics in bronchiectasis. Air trapping and diffusion impairment, not airflow obstruction, represent the most common functional abnormalities. RVrev is related to worse lung function and might be considered in bronchiectasis' workup and for patients' functional stratification.

Bronchial thermoplasty reduces gas trapping in severe asthma

Background

In randomized controlled trials, bronchial thermoplasty (BT) has been proven to reduce symptoms in severe asthma, but the mechanisms by which this is achieved are uncertain as most studies have shown no improvement in spirometry. We postulated that BT might improve lung mechanics by altering airway resistance in the small airways of the lung in ways not measured by FEV₁. This study aimed to evaluate changes in measures of gas trapping by body plethysmography.

Methods

A prospective cohort of 32 consecutive patients with severe asthma who were listed for BT at two Australian university hospitals were evaluated at three time points, namely baseline, and then 6 weeks and 6 months post completion of all procedures. At each evaluation, medication usage, symptom scores (Asthma Control Questionnaire, ACQ-5) and exacerbation history were obtained, and lung function was evaluated by (i) spirometry (ii) gas diffusion (KCO) and (iii) static lung volumes by body plethysmography.

Results

ACQ-5 improved from 3.0 ± 0.8 at baseline to 1.5 ± 0.9 at 6 months (mean ± SD, p < 0.001, paired t-test). Daily salbutamol usage improved from 8.3 ± 5.6 to 3.5 ± 4.3 puffs per day (p < 0.001). Oral corticosteroid requiring exacerbations reduced from 2.5 ± 2.0 in the 6 months prior to BT, to 0.6 ± 1.3 in the 6 months after BT (p < 0.001). The mean baseline FEV₁ was 57.8 ± 18.9%predicted, but no changes in any spirometric parameter were observed after BT. KCO was also unaltered by BT. A significant reduction in gas trapping was observed with Residual Volume (RV) falling from 146 ± 37% predicted at baseline to 136 ± 29%predicted 6 months after BT (p < 0.005). Significant improvements in TLC and FRC were also observed. These changes were evident at the 6 week time period and maintained at 6 months. The change in RV was inversely correlated with the baseline FEV₁ (r = 0.572, p = 0.001), and in patients with a baseline FEV₁ of < 60%predicted, the RV/TLC ratio fell by 6.5 ± 8.9%.

Conclusion

Bronchial thermoplasty improves gas trapping and this effect is greatest in the most severely obstructed patients. The improvement may relate to changes in the mechanical properties of small airways that are not measured with spirometry.

Studying the effect of abdominal massage on the gastric residual volume in patients hospitalized in intensive care units

Background

The main problem of hospitalized patients in intensive care units is feeding, and if the patient does not receive the daily caloric intake required to his body, he will have malnutrition and problems related to it. Abdominal massage is a method used to improve digestive function in various studies, but few studies have been conducted in intensive care units, and sometimes, contradictory results have been obtained. Therefore, the present study is conducted with the aim of determining the effect of abdominal massage on the gastric residual volume in patients hospitalized in intensive care units.

Methods

This study was conducted as a clinical trial in Ahwaz, in 2017. Samples were 60 patients hospitalized in intensive care units who were randomly divided into case and control groups. The intervention period for the case group was 3 days and twice daily for 20 min. Measuring the gastric residual volume was investigated before the intervention and 1 hour after the second massage each day. Data were entered into the checklist designed by the researcher and were analyzed using SPSS version 24 and descriptive and inferential tests.

Results

The gastric residual volume on the second and third day after the intervention was less than before the intervention (p value< 0.05), the gastric residual volume before intervention with after intervention in the control group during different days, on each of the 3 days after the intervention, was more than before the intervention (p value< 0.05), and the gastric residual volume after the intervention in different days and the mean of different days in the case group was lower than the control group (p value> 0.05).

Conclusion

Results represent the effect of abdominal massage on reducing the gastric residual volume in patients hospitalized in intensive care units. Therefore, it is suggested that this method can be considered as a caring method in the daily care program for these patients.

Trial registration

IRCT2017062134641N2, registered 26 July 2017.

Accuracy of postvoid residual volumes after vaginal delivery: a prospective equivalence study to compare an automatic scanning device with transurethral catheterization

Introduction and hypothesis

Abnormal postvoid residual volumes (PVRV) after delivery are common in daily clinical practice. By using an automatic scanning device, unnecessary catheterizations can be prevented. The aim of this study was to determine the accuracy of PVRV after vaginal delivery measured by an automatic scanning device through a comparison with transurethral catheterization.

Materials and methods

This prospective observational equivalence study was performed in patients who delivered vaginally between June 2012 and May 2017 in three teaching hospitals in The Netherlands. After the first spontaneous void after delivery, postvoid residual volume (PVRV) was measured with a portable automatic scanning device (BladderScan® BVI 9400). Directly afterward, it was measured by catheterization. Correlation between measurements was calculated using Spearman’s correlation coefficient and agreement plot. The primary outcome was to validate the correlation between the BladderScan® compared with the gold standard of transurethral catheterization.

Results

Data of 407 patients was used for final analysis. Median PVRV as measured by BladderScan® was 380 ml (± 261–0–999 ml) and by catheterization was 375 ml (± 315–1800 ml). Mean difference between measurements was −12.9 ml (± 178 ml). There was a very good correlation between methods (Spearman’s rho = 0.82, p < 0.001). Using a cut-ff value of >500 ml, specificity and sensitivity were 85.4 and 85.6%, respectively.

Conclusions

The BladderScan® (BVI 9400) measures PVRV precisely and reliably after vaginal delivery and should be preferred over catheterization.

Short-term Analysis of the Residual Volume of an Eye Drop Following 23-Gauge Microincision Vitrectomy Surgery

Purpose

To evaluate the change of residual volume of eye drop after instillation in patients with 23-gauge microincision vitrectomy surgery (MIVS).

Methods

Patient who were treated 23-gauge MIVS from November 2014 to July 2015 were included. The residual volume was defined as the amount of remnant eye drop in patient's eyes after instillation, calculated as the difference between instillation volume and spilled volume of eye drop. Calculation of residual volume of eye drop was performed one day before surgery, and daily from postoperative day 1 to day 5.

Results

Forty consecutive patients were included. The residual volume of eye drop decreased from 30.3 ± 1.4 µL at baseline to 13.0 ± 1.5 µL at day 1, 18.3 ± 1.6 µL at day 2, 24.7 ± 1.5 µL at day 3, and 27.9 ± 1.4 µL in day 4, postoperatively (p < 0.001, respectively). The volume at postoperative day 5 was 29.4 ± 1.3 µL, but it was not different from the volume at baseline (p = 0.105). The change of residual volume was significantly correlated with postoperative chemosis (r = 0.672, p < 0.001) and effected by the number of quadrant with postoperative chemosis (p < 0.05).

Conclusions

This study shows that postoperative residual volume of eye drop after instillation decreased until postoperative day 4, and postoperative chemosis affects the change of residual volume. Thus, checking proper use of eye drops and teaching about instillation technique by physician is necessary for patients with 23-gauge MIVS.

The association between an abnormal post-voiding urine volume and a lower estimated glomerular filtration rate in patients with type 2 diabetes with no voiding symptoms

BACKGROUND/AIMS

Diabetic cystopathy is a frequent complication of diabetes mellitus. This study assessed the association between the post-voiding residual (PVR) urine volume and diabetic nephropathy in type 2 diabetics with no voiding symptoms.

METHODS

This study investigated 42 patients with type 2 diabetes who were followed regularly at our outpatient clinic between July 1, 2008 and June 30, 2009. No patient had voiding problems or International Prostate Symptom Scores (IPSSs) ≥ 12. An urologist performed the urological evaluations and the PVR was measured using a bladder scan. A PVR > 50 mL on two consecutive voids was considered abnormal, which was the primary study outcome.

RESULTS

The mean patient age was 60 ± 10 years; the IPSS score was 3.7 ± 3.3; and the diabetes duration was 11.9 ± 7.8 years. Seven of the 42 patients (16.7%) had a PVR > 50 mL. The presence of overt proteinuria or microalbuminuria was associated with an increased risk of a PVR > 50 mL (p < 0.01). Patients with a PVR > 50 mL had a significantly lower estimated glomerular filtration rate (eGFR) compared with those with a PVR ≤ 50 mL (59.2 ± 27.1 mL/min/1.73 m(2) vs. 28.7 ± 23.3 mL/min/1.73 m(2); p < 0.001). Multivariate logistic analysis revealed that a lower eGFR (odds ratio, 0.94; 95% confidence interval, 0.88 to 0.99; p = 0.04) was a significant risk factor for a PVR > 50 mL.

CONCLUSIONS

Patients with diabetic nephropathy had a significantly higher PVR and a lower eGFR was associated with an abnormal PVR.

Pulmonary outcome in former preterm, very low birth weight children with bronchopulmonary dysplasia: a case-control follow-up at school age

OBJECTIVE

To assess and compare long-term pulmonary outcomes in former preterm-born, very low birth weight (VLBW) children with and without bronchopulmonary dysplasia (BPD) born in the surfactant era.

STUDY DESIGN

Pulmonary function tests (ie, spirometry, body plethysmography, and gas transfer testing) were performed in children with a history of VLBW and BPD (n = 28) and compared with a matched preterm-born VLBW control group (n = 28). Medical history was evaluated by questionnaire.

RESULTS

At time of follow-up (mean age, 9.5 years), respiratory symptoms (36% vs 8%) and receipt of asthma medication (21% vs 0%) were significantly more frequent in the preterm-born children with previous BPD than in those with no history of BPD. The children with a history of BPD had significantly lower values for forced expiratory volume in 1 second (z-score -1.27 vs -0.4; P = .008), forced vital capacity (z-score -1.39 vs -0.71 z-score; P = .022), and forced expiratory flow rate at 50% of forced vital capacity (z-score -2.21 vs -1.04; P = .048) compared with the preterm control group.

CONCLUSION

Preterm-born children with a history of BPD are significantly more likely to have lung function abnormalities, such as airway obstruction and respiratory symptoms, at school age compared with preterm-born children without BPD.

Impact of disease severity on gastric residual volume in critical patients

AIM: To investigate whether illness severity has an impact on gastric residual volume (GRV) in medical critically ill patients.

METHODS: Medical intensive care unit (ICU) patients requiring nasogastric feeding were enrolled. Sequential Organ Failure Assessment (SOFA) score was assessed immediately preceding the start of the study. Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded on the first, fourth, seventh, and fourteenth day of the study period. GRV was measured every 4 h during enteral feeding. The relationship between mean daily GRV and SOFA scores and the correlation between mean daily GRV and mean APACHE II score of all patients were evaluated and compared.

RESULTS: Of the 61 patients, 43 patients were survivors and 18 patients were non-survivors. The mean daily GRV increased as SOFA scores increased (P < 0.001, analysis of variance). Mean APACHE II scores of all patients correlated with mean daily GRV (P = 0.011, Pearson correlation) during the study period. Patients with decreasing GRV in the first 2 d had better survival than patients without decreasing GRV (P = 0.017, log rank test).

CONCLUSION: GRV is higher in more severely ill medical ICU patients. Patients with decreasing GRV had lower ICU mortality than patients without decreasing GRV.